[FFmpeg-devel] [PATCH 2/2] lavf/assenc: handle extra sections after Events

[wm4]

On Sat,  4 Apr 2015 05:31:22 -0500
Rodger Combs <rodger.combs at gmail.com> wrote:

> ---
>  libavformat/assenc.c | 28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/libavformat/assenc.c b/libavformat/assenc.c
> index 3fb9384..5222616 100644
> --- a/libavformat/assenc.c
> +++ b/libavformat/assenc.c
> @@ -40,6 +40,8 @@ typedef struct ASSContext {
>      int cache_size;
>      int ssa_mode;
>      int ignore_readorder;
> +    uint8_t *trailer;
> +    size_t trailer_size;
>  } ASSContext;
>  
>  static int write_header(AVFormatContext *s)
> @@ -55,8 +57,23 @@ static int write_header(AVFormatContext *s)
>      ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS;
>      avpriv_set_pts_info(s->streams[0], 64, 1, 100);
>      if (avctx->extradata_size > 0) {
> -        avio_write(s->pb, avctx->extradata, avctx->extradata_size);
> -        if (avctx->extradata[avctx->extradata_size - 1] != '\n')
> +        size_t header_size = avctx->extradata_size;
> +        uint8_t *trailer = strstr(avctx->extradata, "\n[Events]");
> +
> +        if (trailer)
> +            trailer = strstr(trailer, "Format:");
> +        if (trailer)
> +            trailer = strstr(trailer, "\n");
> +
> +        if (trailer++) {
> +            header_size = (trailer - avctx->extradata);
> +            ass->trailer_size = avctx->extradata_size - header_size;
> +            if (ass->trailer_size)
> +                ass->trailer = trailer;
> +        }
> +
> +        avio_write(s->pb, avctx->extradata, header_size);
> +        if (avctx->extradata[header_size - 1] != '\n')
>              avio_write(s->pb, "\r\n", 2);
>          ass->ssa_mode = !strstr(avctx->extradata, "\n[V4+ Styles]");
>          if (!strstr(avctx->extradata, "\n[Events]"))
> @@ -192,7 +209,14 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
>  
>  static int write_trailer(AVFormatContext *s)
>  {
> +    ASSContext *ass = s->priv_data;
> +
>      purge_dialogues(s, 1);
> +
> +    if (ass->trailer) {
> +        avio_write(s->pb, ass->trailer, ass->trailer_size);
> +    }
> +
>      return 0;
>  }
>  

What extra sections are these? Fonts?