[FFmpeg-devel] [PATCH] lavf/utils: Fix DTS for short H264 streams.

[Michael Niedermayer]

On Fri, Mar 11, 2016 at 12:34:19PM -0800, Sasi Inguva wrote:
> Fill DTS if all packets have been read in avformat_find_stream_info, and still
> has_decode_delay_been_guessed returns false.
> 
> Signed-off-by: Sasi Inguva <isasi at google.com>
> ---
>  libavformat/utils.c | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index 5f48de1..f22309d 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -877,6 +877,7 @@ static int has_decode_delay_been_guessed(AVStream *st)
>         avpriv_h264_has_num_reorder_frames(st->codec) == st->codec->has_b_frames)
>          return 1;
>  #endif
> +
>      if (st->codec->has_b_frames<3)
>          return st->nb_decoded_frames >= 7;
>      else if (st->codec->has_b_frames<4)
> @@ -3165,6 +3166,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
>      int64_t max_stream_analyze_duration;
>      int64_t max_subtitle_analyze_duration;
>      int64_t probesize = ic->probesize;
> +    int eof_reached = 0;
>  
>      flush_codecs = probesize > 0;
>  
> @@ -3331,6 +3333,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
>  
>          if (ret < 0) {
>              /* EOF or error*/
> +            eof_reached = 1;
>              break;
>          }
>  
> @@ -3454,6 +3457,40 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
>          count++;
>      }
>  
> +    if (eof_reached && ic->internal->packet_buffer) {
> +        int stream_index;
> +        for (stream_index = 0; stream_index < ic->nb_streams; stream_index++) {
> +            AVPacketList *pktl = ic->internal->packet_buffer;
> +            int64_t pts_buffer[MAX_REORDER_DELAY+1];
> +
> +            // EOF already reached while reading the stream above.
> +            // So continue with reoordering DTS with whatever delay we have.
> +            int codec_delay = st->codec->has_b_frames;
> +
> +            st = ic->streams[stream_index];
> +

> +            if (st->codec->codec_id != AV_CODEC_ID_H264 ||
> +                has_decode_delay_been_guessed(st)) {
> +                continue;
> +            }

has_decode_delay_been_guessed already contains the H264 check, theres
no need to duplicate it here



> +
> +
> +            for (; pktl; pktl = get_next_pkt(ic, st, pktl)) {
> +                if (pktl->pkt.stream_index != stream_index)
> +                    continue;
> +
> +                if (pktl->pkt.pts != AV_NOPTS_VALUE && codec_delay <= MAX_REORDER_DELAY) {
> +                    int j;
> +                    pts_buffer[0] = pktl->pkt.pts;
> +                    for (j = 0; j < codec_delay && pts_buffer[j] > pts_buffer[j + 1]; j++)
> +                      FFSWAP(int64_t, pts_buffer[j], pts_buffer[j + 1]);

wrong indention


> +
> +                    pktl->pkt.dts = select_from_pts_buffer(st, pts_buffer, pktl->pkt.dts);
> +                }
> +            }

this loop occurs elsewhere too, please factor it into a function
and not duplicate it otherwise it certainly would become out of
sync if either is changed

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

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
-------------- 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/20160312/ad68497b/attachment.sig>