libv4lconvert: remove broken ALTERNATE handling

libv4lconvert: remove broken ALTERNATE handling

[Hans Verkuil]

The V4L2 specification used to say that if field == V4L2_FIELD_ALTERNATE, the
height would have to be divided by two. This is incorrect, the height is that of
a single field. This has been corrected in the spec, now this code in libv4lconvert
needs to be removed as well.

Tested with both bttv and saa7146, the only two drivers supporting FIELD_ALTERNATE
today.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 lib/libv4lconvert/libv4lconvert.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/lib/libv4lconvert/libv4lconvert.c b/lib/libv4lconvert/libv4lconvert.c
index e2afc27..df06b75 100644
--- a/lib/libv4lconvert/libv4lconvert.c
+++ b/lib/libv4lconvert/libv4lconvert.c
@@ -1328,13 +1328,6 @@ int v4lconvert_convert(struct v4lconvert_data *data,
 		return to_copy;
 	}
 
-	/* When field is V4L2_FIELD_ALTERNATE, each buffer only contains half the
-	   lines */
-	if (my_src_fmt.fmt.pix.field == V4L2_FIELD_ALTERNATE) {
-		my_src_fmt.fmt.pix.height /= 2;
-		my_dest_fmt.fmt.pix.height /= 2;
-	}
-
 	/* sanity check, is the dest buffer large enough? */
 	switch (my_dest_fmt.fmt.pix.pixelformat) {
 	case V4L2_PIX_FMT_RGB24:
-- 
1.9.0

Re: libv4lconvert: remove broken ALTERNATE handling

[Hans de Goede]

Hi,

On 03/14/2014 01:39 PM, Hans Verkuil wrote:
> The V4L2 specification used to say that if field == V4L2_FIELD_ALTERNATE, the
> height would have to be divided by two. This is incorrect, the height is that of
> a single field. This has been corrected in the spec, now this code in libv4lconvert
> needs to be removed as well.
> 
> Tested with both bttv and saa7146, the only two drivers supporting FIELD_ALTERNATE
> today.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  lib/libv4lconvert/libv4lconvert.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/lib/libv4lconvert/libv4lconvert.c b/lib/libv4lconvert/libv4lconvert.c
> index e2afc27..df06b75 100644
> --- a/lib/libv4lconvert/libv4lconvert.c
> +++ b/lib/libv4lconvert/libv4lconvert.c
> @@ -1328,13 +1328,6 @@ int v4lconvert_convert(struct v4lconvert_data *data,
>  		return to_copy;
>  	}
>  
> -	/* When field is V4L2_FIELD_ALTERNATE, each buffer only contains half the
> -	   lines */
> -	if (my_src_fmt.fmt.pix.field == V4L2_FIELD_ALTERNATE) {
> -		my_src_fmt.fmt.pix.height /= 2;
> -		my_dest_fmt.fmt.pix.height /= 2;
> -	}
> -
>  	/* sanity check, is the dest buffer large enough? */
>  	switch (my_dest_fmt.fmt.pix.pixelformat) {
>  	case V4L2_PIX_FMT_RGB24:
> 

Looks good, feel free to pish this.

Regards,

Hans