[FFmpeg-devel] [PATCH] webm_dash_manifest_demuxer: Fix initialization range for files with cues at the front

[Vignesh Venkatasubramanian]

On Fri, Apr 21, 2017 at 8:40 AM, Derek Buitenhuis
<derek.buitenhuis at gmail.com> wrote:
> The WebM DASH spec states:
>     The Initialization Segment shall not contain Clusters or Cues.
>     The Segment Index corresponds to the Cues.
>
> Previously, it included the cues if they were at the front.

Looks good. Thanks.

>
> Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
> ---
>  libavformat/matroskadec.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> index 9adca8d..b3f68d3 100644
> --- a/libavformat/matroskadec.c
> +++ b/libavformat/matroskadec.c
> @@ -3815,7 +3815,7 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t
>      return (int64_t)bandwidth;
>  }
>
> -static int webm_dash_manifest_cues(AVFormatContext *s)
> +static int webm_dash_manifest_cues(AVFormatContext *s, int64_t init_range)
>  {
>      MatroskaDemuxContext *matroska = s->priv_data;
>      EbmlList *seekhead_list = &matroska->seekhead;
> @@ -3854,6 +3854,11 @@ static int webm_dash_manifest_cues(AVFormatContext *s)
>      // cues end
>      av_dict_set_int(&s->streams[0]->metadata, CUES_END, cues_end, 0);
>
> +    // if the file has cues at the start, fix up the init range so tht

*that

> +    // it does not include it
> +    if (cues_start <= init_range)
> +        av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, cues_start - 1, 0);
> +
>      // bandwidth
>      bandwidth = webm_dash_manifest_compute_bandwidth(s, cues_start);
>      if (bandwidth < 0) return -1;
> @@ -3883,6 +3888,7 @@ static int webm_dash_manifest_read_header(AVFormatContext *s)
>  {
>      char *buf;
>      int ret = matroska_read_header(s);
> +    int64_t init_range;
>      MatroskaTrack *tracks;
>      MatroskaDemuxContext *matroska = s->priv_data;
>      if (ret) {
> @@ -3903,7 +3909,8 @@ static int webm_dash_manifest_read_header(AVFormatContext *s)
>
>          // initialization range
>          // 5 is the offset of Cluster ID.
> -        av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, avio_tell(s->pb) - 5, 0);
> +        init_range = avio_tell(s->pb) - 5;
> +        av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, init_range, 0);
>      }
>
>      // basename of the file
> @@ -3916,7 +3923,7 @@ static int webm_dash_manifest_read_header(AVFormatContext *s)
>
>      // parse the cues and populate Cue related fields
>      if (!matroska->is_live) {
> -        ret = webm_dash_manifest_cues(s);
> +        ret = webm_dash_manifest_cues(s, init_range);
>          if (ret < 0) {
>              av_log(s, AV_LOG_ERROR, "Error parsing Cues\n");
>              return ret;
> --
> 1.8.3.1
>



-- 
Vignesh