[FFmpeg-devel] [PATCH 1/2] avcodec/cbs: Remove CBS_CONTENT_TYPE_POD

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Sat Oct 22 01:17:44 EEST 2022


Andreas Rheinhardt:
> It is equivalent to CBS_CONTENT_TYPE_INTERNAL_REFS
> with nb_offsets equal to zero.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavcodec/cbs.c          | 18 ++++--------------
>  libavcodec/cbs_internal.h | 21 ++++++++++++---------
>  2 files changed, 16 insertions(+), 23 deletions(-)
> 
> diff --git a/libavcodec/cbs.c b/libavcodec/cbs.c
> index 8d6e3c3442..504197e06d 100644
> --- a/libavcodec/cbs.c
> +++ b/libavcodec/cbs.c
> @@ -839,12 +839,10 @@ void ff_cbs_delete_unit(CodedBitstreamFragment *frag,
>  static void cbs_default_free_unit_content(void *opaque, uint8_t *data)
>  {
>      const CodedBitstreamUnitTypeDescriptor *desc = opaque;
> -    if (desc->content_type == CBS_CONTENT_TYPE_INTERNAL_REFS) {
> -        int i;
> -        for (i = 0; i < desc->type.ref.nb_offsets; i++) {
> -            void **ptr = (void**)(data + desc->type.ref.offsets[i]);
> -            av_buffer_unref((AVBufferRef**)(ptr + 1));
> -        }
> +
> +    for (int i = 0; i < desc->type.ref.nb_offsets; i++) {
> +        void **ptr = (void**)(data + desc->type.ref.offsets[i]);
> +        av_buffer_unref((AVBufferRef**)(ptr + 1));
>      }
>      av_free(data);
>  }
> @@ -981,14 +979,6 @@ static int cbs_clone_unit_content(CodedBitstreamContext *ctx,
>          return AVERROR(ENOSYS);
>  
>      switch (desc->content_type) {
> -    case CBS_CONTENT_TYPE_POD:
> -        ref = av_buffer_alloc(desc->content_size);
> -        if (!ref)
> -            return AVERROR(ENOMEM);
> -        memcpy(ref->data, unit->content, desc->content_size);
> -        err = 0;
> -        break;
> -
>      case CBS_CONTENT_TYPE_INTERNAL_REFS:
>          err = cbs_clone_internal_refs_unit_content(&ref, unit, desc);
>          break;
> diff --git a/libavcodec/cbs_internal.h b/libavcodec/cbs_internal.h
> index 5ccba3c901..045df91744 100644
> --- a/libavcodec/cbs_internal.h
> +++ b/libavcodec/cbs_internal.h
> @@ -31,9 +31,7 @@
>  
>  
>  enum CBSContentType {
> -    // Unit content is a simple structure.
> -    CBS_CONTENT_TYPE_POD,
> -    // Unit content contains some references to other structures, but all
> +    // Unit content may contain some references to other structures, but all
>      // managed via buffer reference counting.  The descriptor defines the
>      // structure offsets of every buffer reference.
>      CBS_CONTENT_TYPE_INTERNAL_REFS,
> @@ -78,9 +76,12 @@ typedef const struct CodedBitstreamUnitTypeDescriptor {
>      size_t content_size;
>  
>      union {
> +        // This union's state is determined by content_type:
> +        // ref for CBS_CONTENT_TYPE_INTERNAL_REFS,
> +        // complex for CBS_CONTENT_TYPE_COMPLEX.
>          struct {
> -            // Number of entries in the ref_offsets array.  Only nonzero
> -            // if the content_type is CBS_CONTENT_TYPE_INTERNAL_REFS.
> +            // Number of entries in the ref_offsets array.
> +            // May be zero, then the structure is POD-like.
>              int nb_offsets;
>              // The structure must contain two adjacent elements:
>              //   type        *field;
> @@ -191,18 +192,20 @@ int ff_cbs_write_signed(CodedBitstreamContext *ctx, PutBitContext *pbc,
>  #define MIN_INT_BITS(length) (-(INT64_C(1) << ((length) - 1)))
>  
>  #define TYPE_LIST(...) { __VA_ARGS__ }
> -#define CBS_UNIT_TYPE_POD(type, structure) { \
> +#define CBS_UNIT_TYPE_POD(type_, structure) { \
>          .nb_unit_types  = 1, \
> -        .unit_type.list = { type }, \
> -        .content_type   = CBS_CONTENT_TYPE_POD, \
> +        .unit_type.list = { type_ }, \
> +        .content_type   = CBS_CONTENT_TYPE_INTERNAL_REFS, \
>          .content_size   = sizeof(structure), \
> +        .type.ref       = { .nb_offsets = 0 }, \
>      }
>  #define CBS_UNIT_RANGE_POD(range_start, range_end, structure) { \
>          .nb_unit_types         = CBS_UNIT_TYPE_RANGE, \
>          .unit_type.range.start = range_start, \
>          .unit_type.range.end   = range_end, \
> -        .content_type          = CBS_CONTENT_TYPE_POD, \
> +        .content_type          = CBS_CONTENT_TYPE_INTERNAL_REFS, \
>          .content_size          = sizeof(structure), \
> +        .type.ref              = { .nb_offsets = 0 }, \
>      }
>  
>  #define CBS_UNIT_TYPES_INTERNAL_REF(types, structure, ref_field) { \

Will apply this patchset tonight unless there are objections.

- Andreas



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