[FFmpeg-devel] [PATCH 16/37] avformat/matroskadec: Treat SimpleBlock as EBML_BIN

[James Almer]

On 5/16/2019 7:30 PM, Andreas Rheinhardt wrote:
> Up until now, the SimpleBlock was treated specially: It basically had
> its own EBML category and it was also included in the BlockGroup EBML
> syntax (although a SimpleBlock must not exist in a BlockGroup according
> to the Matroska specifications). The latter fact also meant that
> a MatroskaBlock's buffer was always unreferenced twice.
> This has been changed: The type of a SimpleBlock is now an EBML_BIN.
> The only way in which SimpleBlocks are still different is that they
> share their associated structure with another unit (namely BlockGroup).
> This is also used to unref the block: It is always unreferenced via the
> BlockGroup syntax.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/matroskadec.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
> index 380db55340..93bf72661c 100644
> --- a/libavformat/matroskadec.c
> +++ b/libavformat/matroskadec.c
> @@ -81,7 +81,6 @@ typedef enum {
>      EBML_BIN,
>      EBML_NEST,
>      EBML_LEVEL1,
> -    EBML_PASS,
>      EBML_STOP,
>      EBML_SINT,
>      EBML_TYPE_COUNT
> @@ -696,7 +695,6 @@ static const EbmlSyntax matroska_blockadditions[] = {
>  static const EbmlSyntax matroska_blockgroup[] = {
>      { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock, bin) },
>      { MATROSKA_ID_BLOCKADDITIONS, EBML_NEST, 0, 0, { .n = matroska_blockadditions} },
> -    { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock, bin) },
>      { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock, duration) },
>      { MATROSKA_ID_DISCARDPADDING, EBML_SINT, 0, offsetof(MatroskaBlock, discard_padding) },
>      { MATROSKA_ID_BLOCKREFERENCE, EBML_SINT, 0, offsetof(MatroskaBlock, reference), { .i = INT64_MIN } },
> @@ -708,7 +706,7 @@ static const EbmlSyntax matroska_blockgroup[] = {
>  static const EbmlSyntax matroska_cluster_parsing[] = {
>      { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) },
>      { MATROSKA_ID_BLOCKGROUP,      EBML_NEST, 0, 0, { .n = matroska_blockgroup } },
> -    { MATROSKA_ID_SIMPLEBLOCK,     EBML_PASS, 0, 0, { .n = matroska_blockgroup } },
> +    { MATROSKA_ID_SIMPLEBLOCK,     EBML_BIN,  0, offsetof(MatroskaBlock, bin) },
>      { MATROSKA_ID_CLUSTERPOSITION, EBML_NONE },
>      { MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE },
>      { MATROSKA_ID_INFO,            EBML_NONE },
> @@ -1179,7 +1177,7 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska,
>          list->nb_elem++;
>      }
>  
> -    if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
> +    if (syntax->type != EBML_STOP) {
>          matroska->current_id = 0;
>          if ((res = ebml_read_length(matroska, pb, &length)) < 0)
>              return res;
> @@ -1253,8 +1251,6 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska,
>              level1_elem->parsed = 1;
>          }
>          return ebml_parse_nest(matroska, syntax->def.n, data);
> -    case EBML_PASS:
> -        return ebml_parse_id(matroska, syntax->def.n, id, data);
>      case EBML_STOP:
>          return 1;
>      default:

Applied (Last night). Thanks.