[FFmpeg-devel] [PATCH] lavf/mov.c: Set skip_samples according to first edit list, when -ignore_editlist is set.

[wm4]

On Fri, 11 Nov 2016 22:02:28 -0800
Sasi Inguva <isasi-at-google.com at ffmpeg.org> wrote:

> Signed-off-by: Sasi Inguva <isasi at google.com>
> ---
>  libavformat/isom.h |  2 ++
>  libavformat/mov.c  | 22 +++++++++++++++++++++-
>  2 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/isom.h b/libavformat/isom.h
> index d684502..6a8a4e3 100644
> --- a/libavformat/isom.h
> +++ b/libavformat/isom.h
> @@ -164,6 +164,8 @@ typedef struct MOVStreamContext {
>      uint32_t tmcd_flags;  ///< tmcd track flags
>      int64_t track_end;    ///< used for dts generation in fragmented movie files
>      int start_pad;        ///< amount of samples to skip due to enc-dec delay
> +    int first_elist_start_time;   ///< first edit list start time.
> +    int num_non_empty_elst;       ///< number of non empty edit lists.
>      unsigned int rap_group_count;
>      MOVSbgp *rap_group;
>  
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index 9ec7d03..676694e 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -3245,6 +3245,12 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
>          }
>      }
>  
> +    /* Adjust skip_samples correctly when ignore_editlist is set, to support gapless playback */
> +    if (mov->ignore_editlist && sc->num_non_empty_elst <= 1 &&
> +        st->codecpar->codec_id == AV_CODEC_ID_AAC && sc->first_elist_start_time > 0) {
> +        sc->start_pad = sc->first_elist_start_time;
> +    }
> +
>      /* only use old uncompressed audio chunk demuxing when stts specifies it */
>      if (!(st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
>            sc->stts_count == 1 && sc->stts_data[0].duration == 1)) {
> @@ -4424,9 +4430,11 @@ static int mov_read_elst(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>      MOVStreamContext *sc;
>      int i, edit_count, version;
>  
> -    if (c->fc->nb_streams < 1 || c->ignore_editlist)
> +    if (c->fc->nb_streams < 1)
>          return 0;
>      sc = c->fc->streams[c->fc->nb_streams-1]->priv_data;
> +    sc->first_elist_start_time = 0;
> +    sc->num_non_empty_elst = 0;
>  
>      version = avio_r8(pb); /* version */
>      avio_rb24(pb); /* flags */
> @@ -4463,9 +4471,21 @@ static int mov_read_elst(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>                     c->fc->nb_streams-1, i, e->time);
>              return AVERROR_INVALIDDATA;
>          }
> +
> +        if (!sc->first_elist_start_time && e->time > 0) {
> +            sc->first_elist_start_time = e->time;
> +        }
> +
> +        if (e->time >= 0) {
> +            sc->num_non_empty_elst++;
> +        }
>      }
>      sc->elst_count = i;
>  
> +    if (c->ignore_editlist) {
> +        av_freep(&sc->elst_data);
> +        sc->elst_count = 0;
> +    }
>      return 0;
>  }
>  

Why only AAC?