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* image quality of Labtec Webcam 2200
@ 2009-09-11  7:09 Németh Márton
  2009-09-11 18:17 ` Németh Márton
  2009-09-13  7:20 ` Jean-Francois Moine
  0 siblings, 2 replies; 12+ messages in thread
From: Németh Márton @ 2009-09-11  7:09 UTC (permalink / raw)
  To: Thomas Kaiser, Jean-Francois Moine; +Cc: V4L Mailing List

Hi,

I have a Labtec Webcam 2200 and I have problems with the image quality
with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
each captured image as raw data and when libv4l was able to convert
then I also stored the result as bmp.

You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
There are three types of problems:
 a) Sometimes the picture contains a 8x8 pixel error, like in image #9
    http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
 b) Sometimes the brightness of the half picture is changed, like in
    images #7, #36 and #37
    http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
    http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
    http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
 c) Sometimes the libv4l cannot convert the raw image and the errno
    is set to EAGAIN (11), for example image #1, #2 and #3

Do you know how can I fix these problems?

Regards,

	Márton Németh

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-11  7:09 image quality of Labtec Webcam 2200 Németh Márton
@ 2009-09-11 18:17 ` Németh Márton
  2009-09-12  0:43   ` leandro Costantino
                     ` (2 more replies)
  2009-09-13  7:20 ` Jean-Francois Moine
  1 sibling, 3 replies; 12+ messages in thread
From: Németh Márton @ 2009-09-11 18:17 UTC (permalink / raw)
  To: Thomas Kaiser, Jean-Francois Moine, Luc Saillard
  Cc: V4L Mailing List, Németh Márton

Márton Németh wrote:
> Hi,
> 
> I have a Labtec Webcam 2200 and I have problems with the image quality
> with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
> each captured image as raw data and when libv4l was able to convert
> then I also stored the result as bmp.
> 
> You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
> There are three types of problems:
>  a) Sometimes the picture contains a 8x8 pixel error, like in image #9
>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>  b) Sometimes the brightness of the half picture is changed, like in
>     images #7, #36 and #37
>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>  c) Sometimes the libv4l cannot convert the raw image and the errno
>     is set to EAGAIN (11), for example image #1, #2 and #3
> 
> Do you know how can I fix these problems?

I investigated the c) point a little bit. When I get a negative return value
from the v4lconvert_convert() function then I print out the error message what the
v4lconvert_get_error_message() function returns. With the result log file
I executed a "grep v4l-convert |sort |uniq" command. All the error messages are
coming from the tinyjpeg.c (Small jpeg decoder library):

v4l-convert: error decompressing JPEG: error: more then 63 AC components (65) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (66) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (67) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (68) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (69) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (70) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (71) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (72) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (73) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (75) in huffman unit
v4l-convert: error decompressing JPEG: error: more then 63 AC components (76) in huffman unit
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x00
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x01
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x02
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x04
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x08
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x09
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x0a
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x10
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x12
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x14
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1a
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1b
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1c
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1f
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x80
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x82
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x87
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x88
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x89
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8a
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8b
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8c
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8d
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8e
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8f
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x90
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x91
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x92
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x93
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x94
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x95
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x96
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x97
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x99
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9b
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9c
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9d
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9e
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9f
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa3
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa5
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa6
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa7
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa9
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaa
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xab
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xad
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaf
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb3
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb5
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb7
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb8
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb9
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbc
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbd
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbe
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbf
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc0
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc4
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc6
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc7
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc9
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcb
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcc
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcf
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd1
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd2
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd3
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd4
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdc
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdf
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe5
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe7
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe8
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xea
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xeb
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xec
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf0
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf2
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf4
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf5
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf8
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf9
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfa
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfc
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfe
v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xff
v4l-convert: error decompressing JPEG: Pixart JPEG error, stream does not end with EOF marker
v4l-convert: error decompressing JPEG: unknown huffman code: 0000ff81
v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffec
v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffff

Regards,

	Márton Németh

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-11 18:17 ` Németh Márton
@ 2009-09-12  0:43   ` leandro Costantino
  2009-09-12  1:21   ` leandro Costantino
       [not found]   ` <c2fe070d0909111741l21120025v3f45eb8566d27c7a@mail.gmail.com>
  2 siblings, 0 replies; 12+ messages in thread
From: leandro Costantino @ 2009-09-12  0:43 UTC (permalink / raw)
  To: V4L Mailing List

Hi ,
i tested it with 2.6.31-rc9 & libvl 0.6.1 + svv  and cannot reproduce.

301147.626826] gspca: probing 093a:2626
[301147.641578] gspca: probe ok
[301147.641607] gspca: probing 093a:2626
[301147.641770] gspca: probing 093a:2626
[301147.641829] usbcore: registered new interface driver pac7311
[301147.641835] pac7311: registered

Could you try testing with svv.c app?

pd: quality is not the best, but works ok. Seem that the format is not
the proper or expected "pjpeg" on your streaming.


2009/9/11 Németh Márton <nm127@freemail.hu>:
> Márton Németh wrote:
>> Hi,
>>
>> I have a Labtec Webcam 2200 and I have problems with the image quality
>> with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
>> each captured image as raw data and when libv4l was able to convert
>> then I also stored the result as bmp.
>>
>> You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
>> There are three types of problems:
>>  a) Sometimes the picture contains a 8x8 pixel error, like in image #9
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>>  b) Sometimes the brightness of the half picture is changed, like in
>>     images #7, #36 and #37
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>>  c) Sometimes the libv4l cannot convert the raw image and the errno
>>     is set to EAGAIN (11), for example image #1, #2 and #3
>>
>> Do you know how can I fix these problems?
>
> I investigated the c) point a little bit. When I get a negative return value
> from the v4lconvert_convert() function then I print out the error message what the
> v4lconvert_get_error_message() function returns. With the result log file
> I executed a "grep v4l-convert |sort |uniq" command. All the error messages are
> coming from the tinyjpeg.c (Small jpeg decoder library):
>
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (65) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (66) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (67) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (68) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (69) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (70) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (71) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (72) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (73) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (75) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (76) in huffman unit
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x00
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x01
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x02
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x04
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x08
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x09
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x0a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x10
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x12
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x14
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x80
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x82
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x87
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x88
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x89
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8d
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8e
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x90
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x91
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x92
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x93
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x94
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x95
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x96
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x97
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x99
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9d
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9e
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa6
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaa
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xab
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xad
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbd
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbe
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc0
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc6
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcb
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd1
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd2
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xea
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xeb
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xec
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf0
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf2
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfa
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfe
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xff
> v4l-convert: error decompressing JPEG: Pixart JPEG error, stream does not end with EOF marker
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ff81
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffec
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffff
>
> Regards,
>
>        Márton Németh
> --
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^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-11 18:17 ` Németh Márton
  2009-09-12  0:43   ` leandro Costantino
@ 2009-09-12  1:21   ` leandro Costantino
       [not found]   ` <c2fe070d0909111741l21120025v3f45eb8566d27c7a@mail.gmail.com>
  2 siblings, 0 replies; 12+ messages in thread
From: leandro Costantino @ 2009-09-12  1:21 UTC (permalink / raw)
  To: Németh Márton
  Cc: Thomas Kaiser, Jean-Francois Moine, Luc Saillard, V4L Mailing List

Also , about the negative value. It happens to when using Pac7311 on
libv4l_convert. Usually it an -EAGAIN, that should be ignored.
svv application, just ignore that, and another apps take in account.
But would be nice to re test your webcam to find where the real problem is.
Best Regards


2009/9/11 Németh Márton <nm127@freemail.hu>:
> Márton Németh wrote:
>> Hi,
>>
>> I have a Labtec Webcam 2200 and I have problems with the image quality
>> with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
>> each captured image as raw data and when libv4l was able to convert
>> then I also stored the result as bmp.
>>
>> You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
>> There are three types of problems:
>>  a) Sometimes the picture contains a 8x8 pixel error, like in image #9
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>>  b) Sometimes the brightness of the half picture is changed, like in
>>     images #7, #36 and #37
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>>  c) Sometimes the libv4l cannot convert the raw image and the errno
>>     is set to EAGAIN (11), for example image #1, #2 and #3
>>
>> Do you know how can I fix these problems?
>
> I investigated the c) point a little bit. When I get a negative return value
> from the v4lconvert_convert() function then I print out the error message what the
> v4lconvert_get_error_message() function returns. With the result log file
> I executed a "grep v4l-convert |sort |uniq" command. All the error messages are
> coming from the tinyjpeg.c (Small jpeg decoder library):
>
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (65) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (66) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (67) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (68) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (69) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (70) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (71) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (72) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (73) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (75) in huffman unit
> v4l-convert: error decompressing JPEG: error: more then 63 AC components (76) in huffman unit
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x00
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x01
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x02
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x04
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x08
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x09
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x0a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x10
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x12
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x14
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x80
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x82
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x87
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x88
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x89
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8a
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8d
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8e
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x90
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x91
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x92
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x93
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x94
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x95
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x96
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x97
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x99
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9b
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9c
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9d
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9e
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9f
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa6
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaa
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xab
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xad
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbd
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbe
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc0
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc6
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcb
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd1
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd2
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd3
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdf
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe7
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xea
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xeb
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xec
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf0
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf2
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf4
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf5
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf8
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf9
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfa
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfc
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfe
> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xff
> v4l-convert: error decompressing JPEG: Pixart JPEG error, stream does not end with EOF marker
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ff81
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffec
> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffff
>
> Regards,
>
>        Márton Németh
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
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>

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
       [not found]     ` <4AAB3CB5.7090106@freemail.hu>
@ 2009-09-12 14:51       ` leandro Costantino
  2009-09-12 18:26         ` Németh Márton
  0 siblings, 1 reply; 12+ messages in thread
From: leandro Costantino @ 2009-09-12 14:51 UTC (permalink / raw)
  To: Németh Márton
  Cc: Thomas Kaiser, Jean-Francois Moine, Luc Saillard, V4L Mailing List

Nice, i will take a look.
Anyway, be aware, that the "conversion error", is something expected
on pac7311, in fact, Hans have commented that on the libv4lconvert.
......
    if (result) {
        /* Pixart webcam's seem to regulary generate corrupt frames, which
           are best thrown away to avoid flashes in the video stream. Tell
           the upper layer this is an intermediate fault and it should try
           again with a new buffer by setting errno to EAGAIN */
        if (src_pix_fmt == V4L2_PIX_FMT_PJPG ||
            data->flags & V4LCONVERT_IS_SN9C20X) {
          V4LCONVERT_ERR("decompressing JPEG: %s",
            tinyjpeg_get_errorstring(data->jdec));
          errno = EAGAIN;
          return -1;
........
That's the result of the EAGAIN.

About, the half brightness picture, did that happens when autogain is off?
Best Regards
On Sat, Sep 12, 2009 at 2:16 AM, Németh Márton <nm127@freemail.hu> wrote:
> Hello,
>
> thank you for looking at this topic.
>
> leandro Costantino wrote:
>> > Hi ,
>> > i tested it with 2.6.31-rc9 & libvl 0.6.1 + svv  and cannot reproduce.
>> >
>> > 301147.626826] gspca: probing 093a:2626
>> > [301147.641578] gspca: probe ok
>> > [301147.641607] gspca: probing 093a:2626
>> > [301147.641770] gspca: probing 093a:2626
>> > [301147.641829] usbcore: registered new interface driver pac7311
>> > [301147.641835] pac7311: registered
>
> I have the same dmesg output. My Labtec Webcam 2200 has the following labels
> on the cable:
>
> M/N: V-UCE52
> P/N: 860-000073
> PID: CE73902
>
> Maybe there is more than one revision of the Labtec Webcam 2200 and I have
> one with a different hardware/firmware inside?
>
>> > Could you try testing with svv.c app?
>
> I used a bit modified svv.c to create the measurement result. The
> modifications are to create the output HTML report and save the raw
> and the BMP images. The display is not correct because I changed
> the format from V4L2_PIX_FMT_RGB24 to V4L2_PIX_FMT_BGR24 to easily
> save the result to BMP. The source code quality is not the best,
> I am sorry about that, but I can still attach my source code which I
> modified a little bit since my last report.
>
>> > pd: quality is not the best, but works ok. Seem that the format is not
>> > the proper or expected "pjpeg" on your streaming.
>
> Do you think about USB transfer problem?
>
> Regards,
>
>        Márton Németh
>
>> > 2009/9/11 Németh Márton <nm127@freemail.hu>:
>>> >> Márton Németh wrote:
>>>> >>> Hi,
>>>> >>>
>>>> >>> I have a Labtec Webcam 2200 and I have problems with the image quality
>>>> >>> with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
>>>> >>> each captured image as raw data and when libv4l was able to convert
>>>> >>> then I also stored the result as bmp.
>>>> >>>
>>>> >>> You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
>>>> >>> There are three types of problems:
>>>> >>>  a) Sometimes the picture contains a 8x8 pixel error, like in image #9
>>>> >>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>>>> >>>  b) Sometimes the brightness of the half picture is changed, like in
>>>> >>>     images #7, #36 and #37
>>>> >>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>>>> >>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>>>> >>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>>>> >>>  c) Sometimes the libv4l cannot convert the raw image and the errno
>>>> >>>     is set to EAGAIN (11), for example image #1, #2 and #3
>>>> >>>
>>>> >>> Do you know how can I fix these problems?
>>> >> I investigated the c) point a little bit. When I get a negative return value
>>> >> from the v4lconvert_convert() function then I print out the error message what the
>>> >> v4lconvert_get_error_message() function returns. With the result log file
>>> >> I executed a "grep v4l-convert |sort |uniq" command. All the error messages are
>>> >> coming from the tinyjpeg.c (Small jpeg decoder library):
>>> >>
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (65) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (66) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (67) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (68) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (69) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (70) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (71) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (72) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (73) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (75) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: error: more then 63 AC components (76) in huffman unit
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x00
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x01
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x02
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x04
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x08
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x09
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x0a
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x10
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x12
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x14
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1a
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1b
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1c
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1f
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x80
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x82
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x87
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x88
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x89
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8a
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8b
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8c
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8d
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8e
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8f
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x90
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x91
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x92
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x93
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x94
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x95
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x96
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x97
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x99
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9b
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9c
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9d
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9e
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9f
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa3
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa5
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa6
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa7
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa9
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaa
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xab
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xad
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaf
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb3
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb5
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb7
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb8
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb9
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbc
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbd
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbe
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbf
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc0
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc4
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc6
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc7
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc9
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcb
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcc
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcf
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd1
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd2
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd3
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd4
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdc
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdf
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe5
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe7
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe8
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xea
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xeb
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xec
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf0
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf2
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf4
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf5
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf8
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf9
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfa
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfc
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfe
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xff
>>> >> v4l-convert: error decompressing JPEG: Pixart JPEG error, stream does not end with EOF marker
>>> >> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ff81
>>> >> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffec
>>> >> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffff
>>> >>
>>> >> Regards,
>>> >>
>>> >>        Márton Németh
>>> >> --
>>> >> To unsubscribe from this list: send the line "unsubscribe linux-media" in
>>> >> the body of a message to majordomo@vger.kernel.org
>>> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-12 14:51       ` leandro Costantino
@ 2009-09-12 18:26         ` Németh Márton
  0 siblings, 0 replies; 12+ messages in thread
From: Németh Márton @ 2009-09-12 18:26 UTC (permalink / raw)
  To: leandro Costantino
  Cc: Thomas Kaiser, Jean-Francois Moine, Luc Saillard,
	V4L Mailing List, Németh Márton

leandro Costantino wrote:
> Nice, i will take a look.
> Anyway, be aware, that the "conversion error", is something expected
> on pac7311, in fact, Hans have commented that on the libv4lconvert.
> ......
>     if (result) {
>         /* Pixart webcam's seem to regulary generate corrupt frames, which
>            are best thrown away to avoid flashes in the video stream. Tell
>            the upper layer this is an intermediate fault and it should try
>            again with a new buffer by setting errno to EAGAIN */
>         if (src_pix_fmt == V4L2_PIX_FMT_PJPG ||
>             data->flags & V4LCONVERT_IS_SN9C20X) {
>           V4LCONVERT_ERR("decompressing JPEG: %s",
>             tinyjpeg_get_errorstring(data->jdec));
>           errno = EAGAIN;
>           return -1;
> ........
> That's the result of the EAGAIN.

The corrupted data coming from the device would be one reason. An other reason
could be the limitation of the libv4l 0.6.1 that it cannot understand the raw data
coming from the webcam. Maybe the raw data does not fulfill the JPEG specification
but still could have some meaning -- which we don't understand at the moment. The
different types of error messages mean for me that at least some of them could be
solved (i.e. "unknown huffman code").

> About, the half brightness picture, did that happens when autogain is off?

Yes, I tried to switch the "Auto Gain" control off before starting a measurement.
The half brightness pictures appears time to time.

Regards,

	Márton Németh

> Best Regards
> On Sat, Sep 12, 2009 at 2:16 AM, Németh Márton <nm127@freemail.hu> wrote:
>> Hello,
>>
>> thank you for looking at this topic.
>>
>> leandro Costantino wrote:
>>>> Hi ,
>>>> i tested it with 2.6.31-rc9 & libvl 0.6.1 + svv  and cannot reproduce.
>>>>
>>>> 301147.626826] gspca: probing 093a:2626
>>>> [301147.641578] gspca: probe ok
>>>> [301147.641607] gspca: probing 093a:2626
>>>> [301147.641770] gspca: probing 093a:2626
>>>> [301147.641829] usbcore: registered new interface driver pac7311
>>>> [301147.641835] pac7311: registered
>> I have the same dmesg output. My Labtec Webcam 2200 has the following labels
>> on the cable:
>>
>> M/N: V-UCE52
>> P/N: 860-000073
>> PID: CE73902
>>
>> Maybe there is more than one revision of the Labtec Webcam 2200 and I have
>> one with a different hardware/firmware inside?
>>
>>>> Could you try testing with svv.c app?
>> I used a bit modified svv.c to create the measurement result. The
>> modifications are to create the output HTML report and save the raw
>> and the BMP images. The display is not correct because I changed
>> the format from V4L2_PIX_FMT_RGB24 to V4L2_PIX_FMT_BGR24 to easily
>> save the result to BMP. The source code quality is not the best,
>> I am sorry about that, but I can still attach my source code which I
>> modified a little bit since my last report.
>>
>>>> pd: quality is not the best, but works ok. Seem that the format is not
>>>> the proper or expected "pjpeg" on your streaming.
>> Do you think about USB transfer problem?
>>
>> Regards,
>>
>>        Márton Németh
>>
>>>> 2009/9/11 Németh Márton <nm127@freemail.hu>:
>>>>>> Márton Németh wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I have a Labtec Webcam 2200 and I have problems with the image quality
>>>>>>>> with Linux 2.6.31 + libv4l 0.6.1. I made some experiments and stored
>>>>>>>> each captured image as raw data and when libv4l was able to convert
>>>>>>>> then I also stored the result as bmp.
>>>>>>>>
>>>>>>>> You can find my results at http://v4l-test.sourceforge.net/results/test-20090911/index.html
>>>>>>>> There are three types of problems:
>>>>>>>>  a) Sometimes the picture contains a 8x8 pixel error, like in image #9
>>>>>>>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>>>>>>>>  b) Sometimes the brightness of the half picture is changed, like in
>>>>>>>>     images #7, #36 and #37
>>>>>>>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>>>>>>>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>>>>>>>>     http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>>>>>>>>  c) Sometimes the libv4l cannot convert the raw image and the errno
>>>>>>>>     is set to EAGAIN (11), for example image #1, #2 and #3
>>>>>>>>
>>>>>>>> Do you know how can I fix these problems?
>>>>>> I investigated the c) point a little bit. When I get a negative return value
>>>>>> from the v4lconvert_convert() function then I print out the error message what the
>>>>>> v4lconvert_get_error_message() function returns. With the result log file
>>>>>> I executed a "grep v4l-convert |sort |uniq" command. All the error messages are
>>>>>> coming from the tinyjpeg.c (Small jpeg decoder library):
>>>>>>
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (65) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (66) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (67) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (68) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (69) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (70) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (71) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (72) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (73) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (75) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: error: more then 63 AC components (76) in huffman unit
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x00
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x01
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x02
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x04
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x08
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x09
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x0a
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x10
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x12
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x14
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1a
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1b
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1c
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x1f
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x80
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x82
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x87
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x88
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x89
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8a
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8b
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8c
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8d
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8e
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x8f
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x90
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x91
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x92
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x93
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x94
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x95
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x96
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x97
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x99
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9b
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9c
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9d
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9e
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0x9f
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa3
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa5
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa6
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa7
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xa9
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaa
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xab
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xad
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xaf
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb3
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb5
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb7
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb8
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xb9
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbc
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbd
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbe
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xbf
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc0
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc4
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc6
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc7
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xc9
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcb
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcc
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xcf
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd1
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd2
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd3
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xd4
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdc
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xdf
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe5
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe7
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xe8
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xea
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xeb
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xec
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf0
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf2
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf4
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf5
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf8
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xf9
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfa
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfc
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xfe
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error: invalid MCU marker: 0xff
>>>>>> v4l-convert: error decompressing JPEG: Pixart JPEG error, stream does not end with EOF marker
>>>>>> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ff81
>>>>>> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffec
>>>>>> v4l-convert: error decompressing JPEG: unknown huffman code: 0000ffff
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>>        Márton Németh

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-11  7:09 image quality of Labtec Webcam 2200 Németh Márton
  2009-09-11 18:17 ` Németh Márton
@ 2009-09-13  7:20 ` Jean-Francois Moine
  2009-09-13 11:00   ` Németh Márton
  2009-09-13 18:48   ` Hans de Goede
  1 sibling, 2 replies; 12+ messages in thread
From: Jean-Francois Moine @ 2009-09-13  7:20 UTC (permalink / raw)
  To: Németh Márton
  Cc: Thomas Kaiser, V4L Mailing List, leandro Costantino, Hans de Goede

On Fri, 11 Sep 2009 09:09:20 +0200
Németh Márton <nm127@freemail.hu> wrote:

> You can find my results at
> http://v4l-test.sourceforge.net/results/test-20090911/index.html
> There are three types of problems: a) Sometimes the picture contains
> a 8x8 pixel error, like in image #9
> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
> b) Sometimes the brightness of the half picture is changed, like in
> images #7, #36 and #37
> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
> c) Sometimes the libv4l cannot convert the raw image and the errno is
> set to EAGAIN (11), for example image #1, #2 and #3
> 
> Do you know how can I fix these problems?

The error EAGAIN is normal when decoding pac7311 images, because they
are rotated 90°. But this error should occur one time only.

I looked at the raw image #1, and it seems that there are JPEG errors
inside (sequences ff ff). There should be a problem in the pac7311
driver. Hans, may you confirm?

-- 
Ken ar c'hentañ	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-13  7:20 ` Jean-Francois Moine
@ 2009-09-13 11:00   ` Németh Márton
  2009-09-13 14:42     ` leandro Costantino
  2009-09-13 18:48   ` Hans de Goede
  1 sibling, 1 reply; 12+ messages in thread
From: Németh Márton @ 2009-09-13 11:00 UTC (permalink / raw)
  To: Jean-Francois Moine
  Cc: Thomas Kaiser, V4L Mailing List, leandro Costantino, Hans de Goede

Jean-Francois Moine wrote:
> On Fri, 11 Sep 2009 09:09:20 +0200
> Németh Márton <nm127@freemail.hu> wrote:
> 
>> You can find my results at
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html
>> There are three types of problems: a) Sometimes the picture contains
>> a 8x8 pixel error, like in image #9
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>> b) Sometimes the brightness of the half picture is changed, like in
>> images #7, #36 and #37
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>> c) Sometimes the libv4l cannot convert the raw image and the errno is
>> set to EAGAIN (11), for example image #1, #2 and #3
>>
>> Do you know how can I fix these problems?
> 
> The error EAGAIN is normal when decoding pac7311 images, because they
> are rotated 90°. But this error should occur one time only.

I have the feeling that the Labtec Webcam 2200 is not based on the PAC7311
but on PAC7312. The PAC7312 also contains a microphone input and the
Labtec Webcam 2200 also have a built-in microphone.
See http://www.pixart.com.tw/productsditel.asp?ToPage=1&productclassify_id=12&productclassify2_id=33
for the datasheets. See also http://labtec.com/index.cfm/gear/details/EUR/EN,crid=30,contentid=761 .

> I looked at the raw image #1, and it seems that there are JPEG errors
> inside (sequences ff ff). There should be a problem in the pac7311
> driver. Hans, may you confirm?
> 


^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-13 11:00   ` Németh Márton
@ 2009-09-13 14:42     ` leandro Costantino
  2009-09-13 15:59       ` Thomas Kaiser
  0 siblings, 1 reply; 12+ messages in thread
From: leandro Costantino @ 2009-09-13 14:42 UTC (permalink / raw)
  To: Németh Márton
  Cc: Jean-Francois Moine, Thomas Kaiser, V4L Mailing List, Hans de Goede

Actually it based on pac7302. Pac7311/02 also has support ( since gspca1 ).

I checked some old logs of the pac, and the driver init for 7302 seems ok.

The "ff ff ff" sequence, seems to been taken in account on conversion.
(libv4lconvert)

/* Special Pixart versions of the *_nbits functions, these remove the special
   ff ff ff xx sequences pixart cams insert from the bitstream */
#define pixart_fill_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted) \

This is really a tricky cam. I be back on windows to do further test.

pd: Nemeth, i could reproduce your problems now.

2009/9/13 Németh Márton <nm127@freemail.hu>:
> Jean-Francois Moine wrote:
>> On Fri, 11 Sep 2009 09:09:20 +0200
>> Németh Márton <nm127@freemail.hu> wrote:
>>
>>> You can find my results at
>>> http://v4l-test.sourceforge.net/results/test-20090911/index.html
>>> There are three types of problems: a) Sometimes the picture contains
>>> a 8x8 pixel error, like in image #9
>>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>>> b) Sometimes the brightness of the half picture is changed, like in
>>> images #7, #36 and #37
>>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>>> c) Sometimes the libv4l cannot convert the raw image and the errno is
>>> set to EAGAIN (11), for example image #1, #2 and #3
>>>
>>> Do you know how can I fix these problems?
>>
>> The error EAGAIN is normal when decoding pac7311 images, because they
>> are rotated 90°. But this error should occur one time only.
>
> I have the feeling that the Labtec Webcam 2200 is not based on the PAC7311
> but on PAC7312. The PAC7312 also contains a microphone input and the
> Labtec Webcam 2200 also have a built-in microphone.
> See http://www.pixart.com.tw/productsditel.asp?ToPage=1&productclassify_id=12&productclassify2_id=33
> for the datasheets. See also http://labtec.com/index.cfm/gear/details/EUR/EN,crid=30,contentid=761 .
>
>> I looked at the raw image #1, and it seems that there are JPEG errors
>> inside (sequences ff ff). There should be a problem in the pac7311
>> driver. Hans, may you confirm?
>>
>
>

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-13 14:42     ` leandro Costantino
@ 2009-09-13 15:59       ` Thomas Kaiser
  2009-09-13 18:50         ` Hans de Goede
  0 siblings, 1 reply; 12+ messages in thread
From: Thomas Kaiser @ 2009-09-13 15:59 UTC (permalink / raw)
  To: leandro Costantino
  Cc: Németh Márton, Jean-Francois Moine, V4L Mailing List,
	Hans de Goede

On 09/13/2009 04:42 PM, leandro Costantino wrote:
> Actually it based on pac7302. Pac7311/02 also has support ( since gspca1 ).
> 
> I checked some old logs of the pac, and the driver init for 7302 seems ok.
> 
> The "ff ff ff" sequence, seems to been taken in account on conversion.
> (libv4lconvert)
> 
> /* Special Pixart versions of the *_nbits functions, these remove the special
>    ff ff ff xx sequences pixart cams insert from the bitstream */
> #define pixart_fill_nbits(reservoir,nbits_in_reservoir,stream,nbits_wanted) \
> 
> This is really a tricky cam. I be back on windows to do further test.

Hey All

I thought Hans will come in, in this discussion.......

Anyway, I introduced support for the PAC7311 in gspcaV1 in 2006 [1]

Pixart is using a proprietary JEPG Format to code the image. It took me 
(and help from Jörg Schummer) more than a year to find out the basics 
to decode a frame.

They have this 0xffffffxx markers in the stream, I don't know for what 
this is good, just skip it. And they have a "MCU marker" for each MCU. 
As we know so far, this MCU marker tells what Quantization table should 
be used for decoding the MCU.

Hans did implement my findings into lib4vl and improved it :-)

So, when you get this errors, this is due to a unknown format Pixart is 
using.

I guess we should know what marker you get and how the image should look 
like.

Don't forget, this is all re-engineered -> guess work!

Thomas


[1] http://www.kaiser-linux.li/index.php?title=PAC7311

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-13  7:20 ` Jean-Francois Moine
  2009-09-13 11:00   ` Németh Márton
@ 2009-09-13 18:48   ` Hans de Goede
  1 sibling, 0 replies; 12+ messages in thread
From: Hans de Goede @ 2009-09-13 18:48 UTC (permalink / raw)
  To: Jean-Francois Moine
  Cc: Németh Márton, Thomas Kaiser, V4L Mailing List,
	leandro Costantino

Hi,

On 09/13/2009 09:20 AM, Jean-Francois Moine wrote:
> On Fri, 11 Sep 2009 09:09:20 +0200
> Németh Márton<nm127@freemail.hu>  wrote:
>
>> You can find my results at
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html
>> There are three types of problems: a) Sometimes the picture contains
>> a 8x8 pixel error, like in image #9
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>> b) Sometimes the brightness of the half picture is changed, like in
>> images #7, #36 and #37
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>> c) Sometimes the libv4l cannot convert the raw image and the errno is
>> set to EAGAIN (11), for example image #1, #2 and #3
>>
>> Do you know how can I fix these problems?
>
> The error EAGAIN is normal when decoding pac7311 images, because they
> are rotated 90°. But this error should occur one time only.
>
> I looked at the raw image #1, and it seems that there are JPEG errors
> inside (sequences ff ff). There should be a problem in the pac7311
> driver. Hans, may you confirm?
>

The pac7311 / pac7302 are very cheap crap cams (I bought one brand new
for 3 euros, and that was not in the bargain bin).

These cams use a custom jpeg format, and we are very luky to be able to
decompress this at all (thanks to some of the wizards who worked on the
original gspca driver).

Yes there are still some issues, but with no documentation what soever,
and unreliable hardware (I've seen hang cams which needed to be unplugged
/ replugged to start working again), I'm afraid there is nothing we can do.

Still if people want to work on improving support for them more power to
then, I'll gladly help where I can. The ff ff you've found are special
Pixart padding sequences, see tinyjpeg.c: pixart_fill_nbits()

Also interesting is the comment about some of the special Pxiart markers
in the tinyjpeg.c: pixart_decode_MCU_2x1_3planes() function. Which
summaries what i've learned while getting pac7302 cams to work (to a
certain extend).

Regards,

Hans

^ permalink raw reply	[flat|nested] 12+ messages in thread
* Re: image quality of Labtec Webcam 2200
  2009-09-13 15:59       ` Thomas Kaiser
@ 2009-09-13 18:50         ` Hans de Goede
  0 siblings, 0 replies; 12+ messages in thread
From: Hans de Goede @ 2009-09-13 18:50 UTC (permalink / raw)
  To: Thomas Kaiser
  Cc: leandro Costantino, Németh Márton, Jean-Francois Moine,
	V4L Mailing List

Hi,

On 09/13/2009 05:59 PM, Thomas Kaiser wrote:
> I thought Hans will come in, in this discussion.......
>

Hey hey, its weekend, give me some time to respond already :)

See my reply higher up in the thread.

Regards,

Hans

^ permalink raw reply	[flat|nested] 12+ messages in thread
end of thread, other threads:[~2009-09-13 18:47 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-09-11  7:09 image quality of Labtec Webcam 2200 Németh Márton
2009-09-11 18:17 ` Németh Márton
2009-09-12  0:43   ` leandro Costantino
2009-09-12  1:21   ` leandro Costantino
     [not found]   ` <c2fe070d0909111741l21120025v3f45eb8566d27c7a@mail.gmail.com>
     [not found]     ` <4AAB3CB5.7090106@freemail.hu>
2009-09-12 14:51       ` leandro Costantino
2009-09-12 18:26         ` Németh Márton
2009-09-13  7:20 ` Jean-Francois Moine
2009-09-13 11:00   ` Németh Márton
2009-09-13 14:42     ` leandro Costantino
2009-09-13 15:59       ` Thomas Kaiser
2009-09-13 18:50         ` Hans de Goede
2009-09-13 18:48   ` Hans de Goede

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