[FFmpeg-devel] [PATCH] libavcodec/mpegvideo_parser: set field_order correctly for progressive mpeg2

[Michael Niedermayer]

On Wed, Dec 06, 2017 at 02:54:50PM -0800, Aman Gupta wrote:
> From: Aman Gupta <aman at tmm1.net>
> 
> ---
>  libavcodec/mpegvideo_parser.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/mpegvideo_parser.c b/libavcodec/mpegvideo_parser.c
> index de70cd5632..be240b6890 100644
> --- a/libavcodec/mpegvideo_parser.c
> +++ b/libavcodec/mpegvideo_parser.c
> @@ -131,7 +131,7 @@ static void mpegvideo_extract_headers(AVCodecParserContext *s,
>                              }
>                          }
>  
> -                        if (!pc->progressive_sequence) {
> +                        if (!pc->progressive_sequence && !progressive_frame) {

Iam not against this if it results in more correct interlaced detection
in practice
But the spec uses progressive_sequence alone to determine the output

    ISO/IEC 13818-2: 1995 (E) / Recommendation ITU-T H.262 (1995 E)

    If progressive_sequence is 0 the period between two successive fields at the output of the decoding
    process is half of the reciprocal of the frame_rate. See Figure 7-20.

So the commit message seems wrong or inprecisse 

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Rewriting code that is poorly written but fully understood is good.
Rewriting code that one doesnt understand is a sign that one is less smart
then the original author, trying to rewrite it will not make it better.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20171207/bf1978b4/attachment.sig>