[FFmpeg-devel] [PATCH 1/6] avformat/matroskaenc: Split assembling CodecPrivate from writing it

[Andreas Rheinhardt]

Andreas Rheinhardt:
> This is in preparation for splitting writing and updating
> extradata more thoroughly later.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavformat/matroskaenc.c | 74 ++++++++++++++++++++++++---------------
>  1 file changed, 46 insertions(+), 28 deletions(-)
> 
> diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
> index 163af8aec8..b4756832eb 100644
> --- a/libavformat/matroskaenc.c
> +++ b/libavformat/matroskaenc.c
> @@ -1099,9 +1099,9 @@ static int get_aac_sample_rates(AVFormatContext *s, MatroskaMuxContext *mkv,
>  }
>  #endif
>  
> -static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
> -                                         const AVCodecParameters *par,
> -                                         AVIOContext *dyn_cp)
> +static int mkv_assemble_native_codecprivate(AVFormatContext *s, AVIOContext *dyn_cp,
> +                                            const AVCodecParameters *par,
> +                                            unsigned *size_to_reserve)
>  {
>      switch (par->codec_id) {
>      case AV_CODEC_ID_VORBIS:
> @@ -1112,7 +1112,7 @@ static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
>              return ff_isom_write_av1c(dyn_cp, par->extradata,
>                                        par->extradata_size, 1);
>          else
> -            put_ebml_void(pb, 4 + 3);
> +            *size_to_reserve = 4 + 3;
>          break;
>  #if CONFIG_MATROSKA_MUXER
>      case AV_CODEC_ID_FLAC:
> @@ -1139,7 +1139,7 @@ static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
>          if (par->extradata_size)
>              avio_write(dyn_cp, par->extradata, par->extradata_size);
>          else
> -            put_ebml_void(pb, MAX_PCE_SIZE + 2 + 4);
> +            *size_to_reserve = 4 + MAX_PCE_SIZE + 2;
>          break;
>  #endif
>      default:
> @@ -1153,21 +1153,21 @@ static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
>      return 0;
>  }
>  
> -static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
> -                                  AVCodecParameters *par,
> -                                  int native_id, int qt_id)
> +static int mkv_assemble_codecprivate(AVFormatContext *s, AVIOContext *dyn_cp,
> +                                     AVCodecParameters *par,
> +                                     int native_id, int qt_id,
> +                                     uint8_t **codecpriv, int *codecpriv_size,
> +                                     unsigned *size_to_reserve)
>  {
>      MatroskaMuxContext av_unused *const mkv = s->priv_data;
> -    AVIOContext *dyn_cp;
> -    uint8_t *codecpriv;
> -    int ret, codecpriv_size;
> +    int ret;
>  
> -    ret = avio_open_dyn_buf(&dyn_cp);
> -    if (ret < 0)
> -        return ret;
> +    *size_to_reserve = 0;
>  
>      if (native_id) {
> -        ret = mkv_write_native_codecprivate(s, pb, par, dyn_cp);
> +        ret = mkv_assemble_native_codecprivate(s, dyn_cp, par, size_to_reserve);
> +        if (ret < 0)
> +            return ret;
>  #if CONFIG_MATROSKA_MUXER
>      } else if (par->codec_type == AVMEDIA_TYPE_VIDEO) {
>          if (qt_id) {
> @@ -1193,7 +1193,7 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
>              if (!par->codec_tag && par->codec_id != AV_CODEC_ID_RAWVIDEO) {
>                  av_log(s, AV_LOG_ERROR, "No bmp codec tag found for codec %s\n",
>                         avcodec_get_name(par->codec_id));
> -                ret = AVERROR(EINVAL);
> +                return AVERROR(EINVAL);
>              }
>  
>              ff_put_bmp_header(dyn_cp, par, 0, 0, mkv->flipped_raw_rgb);
> @@ -1204,7 +1204,7 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
>          if (!tag) {
>              av_log(s, AV_LOG_ERROR, "No wav codec tag found for codec %s\n",
>                     avcodec_get_name(par->codec_id));
> -            ret = AVERROR(EINVAL);
> +            return AVERROR(EINVAL);
>          }
>          if (!par->codec_tag)
>              par->codec_tag = tag;
> @@ -1213,14 +1213,32 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
>  #endif
>      }
>  
> -    if (ret >= 0) {
> -        codecpriv_size = avio_get_dyn_buf(dyn_cp, &codecpriv);
> -        if ((ret = dyn_cp->error) >= 0 && codecpriv_size)
> -            put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv,
> -                            codecpriv_size);
> -    }
> -    ffio_free_dyn_buf(&dyn_cp);
> -    return ret;
> +    *codecpriv_size = avio_get_dyn_buf(dyn_cp, codecpriv);
> +    if (dyn_cp->error < 0)
> +        return dyn_cp->error;
> +    return 0;
> +}
> +
> +static int mkv_write_codecprivate(AVFormatContext *s, MatroskaMuxContext *mkv,
> +                                  AVCodecParameters *par,
> +                                  int native_id, int qt_id, AVIOContext *pb)
> +{
> +    AVIOContext *const dyn_bc = mkv->tmp_bc;
> +    uint8_t *codecpriv;
> +    unsigned size_to_reserve;
> +    int ret, codecpriv_size;
> +
> +    ret = mkv_assemble_codecprivate(s, dyn_bc, par, native_id, qt_id,
> +                                    &codecpriv, &codecpriv_size, &size_to_reserve);
> +    if (ret < 0)
> +        goto end;
> +    if (codecpriv_size)
> +        put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
> +    if (size_to_reserve)
> +        put_ebml_void(pb, size_to_reserve);
> +end:
> +    ffio_reset_dyn_buf(dyn_bc);
> +    return 0;
>  }
>  
>  #define MAX_VIDEO_COLOR_ELEMS 20
> @@ -1833,7 +1851,7 @@ static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv,
>  
>      if (!IS_WEBM(mkv) || par->codec_id != AV_CODEC_ID_WEBVTT) {
>          track->codecpriv_offset = avio_tell(pb);
> -        ret = mkv_write_codecprivate(s, pb, par, native_id, qt_id);
> +        ret = mkv_write_codecprivate(s, mkv, par, native_id, qt_id, pb);
>          if (ret < 0)
>              return ret;
>      }
> @@ -2626,7 +2644,7 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
>                  return ret;
>              memcpy(par->extradata, side_data, side_data_size);
>              avio_seek(mkv->track.bc, track->codecpriv_offset, SEEK_SET);
> -            mkv_write_codecprivate(s, mkv->track.bc, par, 1, 0);
> +            mkv_write_codecprivate(s, mkv, par, 1, 0, mkv->track.bc);
>              filler = MAX_PCE_SIZE + 2 + 4 - (avio_tell(mkv->track.bc) - track->codecpriv_offset);
>              if (filler)
>                  put_ebml_void(mkv->track.bc, filler);
> @@ -2649,7 +2667,7 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
>              }
>              par->extradata = side_data;
>              avio_seek(mkv->track.bc, track->codecpriv_offset, SEEK_SET);
> -            mkv_write_codecprivate(s, mkv->track.bc, par, 1, 0);
> +            mkv_write_codecprivate(s, mkv, par, 1, 0, mkv->track.bc);
>              par->extradata = old_extradata;
>          }
>          break;

Will apply this patchset later today unless there are objections.

- Andreas