Re: saa7146: please test the vb2 conversion!

[Stefan Herdler <herdler@nurfuerspam.de>]

On 07/04/23 09:04, Hans Verkuil wrote:
> On 07/04/2023 00:43, Stefan Herdler wrote:
[...]
>>
>> VBI output is used to switch the aspect-ratio via WSS.
>> this should be supported by any av7110 card.
>>
>> The software is run a daemon or plugin, so the userspace-facing change
>> shouldn't matter.
>>
>> I'll test this as soon as possible.
>>
>>
>>
>>
>> I've done only basic testing so far, but unfortunately it already failed.
>>
>> The test:
>> Switch to a channel[*] and view the decoded video with tvtime.
>>
>> The resulting picture is corrupted.
>> Almost green with some pink traces at the outlines.
>>
>> It reminds me to YCbCr component-yideo on a RGB-input.
>> Maybe the input-format of saa7146 not set correctly?
>>
>> The OSD is equally affected, but the card seems to run stable.
>
> That's weird. When you are in this state, can you run
> 'v4l2-ctl -V -d /dev/videoX' for the video device that tvtime
> is using? I'll try to test it with tvtime as well next week.
> I have done my tests using qvidcap and qv4l2, and that looked fine.

I've done some more testing and the result is somehow confusing to me.

At first I tried qv4l and it shows correct videos with any driver.
And with any pixel format setting I tried.


After boot /dev/video0 (there is only this device) starts always with
this settings:
Format Video Capture:
        Width/Height      : 384/288
        Pixel Format      : 'BGR3' (24-bit BGR 8-8-8)
        Field             : Interlaced
        Bytes per Line    : 1152
        Size Image        : 331776
        Colorspace        : SMPTE 170M
        Transfer Function : Default (maps to Rec. 709)
        YCbCr/HSV Encoding: Default (maps to ITU-R 601)
        Quantization      : Default (maps to Full Range)
        Flags             :


On the working "old" driver tvtime switches to the following settings:
Format Video Capture:
        Width/Height      : 720/576
        Pixel Format      : 'UYVY' (UYVY 4:2:2)
        Field             : Interlaced
        Bytes per Line    : 1440
        Size Image        : 829440
        Colorspace        : SMPTE 170M
        Transfer Function : Default (maps to Rec. 709)
        YCbCr/HSV Encoding: Default (maps to ITU-R 601)
        Quantization      : Default (maps to Limited Range)
        Flags             :
It seems tvtime needs this 'UYVY' pixel format to work.


On the "new" driver, with patches [1], tvtime switches to:
Format Video Capture:
        Width/Height      : 720/576
        Pixel Format      : 'BGR3' (24-bit BGR 8-8-8)
        Field             : Interlaced
        Bytes per Line    : 2160
        Size Image        : 1244160
        Colorspace        : SMPTE 170M
        Transfer Function : Default (maps to Rec. 709)
        YCbCr/HSV Encoding: Default (maps to ITU-R 601)
        Quantization      : Default (maps to Full Range)
        Flags             :
And now it is getting weird:
I can switch to the correct 'UYVY' settings using qv4l.
But tvtime always switches back to 'BGR3'.

Using qv4l while tvtime is running doesn't work and sometimes
causes freezing of both programs (on all drivers).


I have also build a new driver just without the patches [2].
It shows the "old" correct behavior.
So I think, the cause of the change must be somewhere in the
patches.



Btw.:
I also tried to open the video device with the usual
media-players, but I had no luck so far (with any driver).


Regards

Stefan


[1] git checkout -B saa7146-clean 837736a79a76c9becddf0caf905b27c144a64030
[2] git checkout -B saa7146-clean 2653fad0d8a9625667e9a78133ea9e1245b7c40c

>
> Regards,
>
> 	Hans
>
[...]