[FFmpeg-devel] [PATCH] avcodec/hevc_ps: allocate only the required HEVCHdrParams within a VPS

[Andreas Rheinhardt]

James Almer:
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  libavcodec/hevc_ps.c     | 17 +++++++++++++++--
>  libavcodec/hevc_ps.h     |  2 +-
>  libavcodec/vulkan_hevc.c |  2 +-
>  3 files changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
> index 20ceb09829..d3edc0810d 100644
> --- a/libavcodec/hevc_ps.c
> +++ b/libavcodec/hevc_ps.c
> @@ -442,13 +442,21 @@ static int decode_hrd(GetBitContext *gb, int common_inf_present,
>      return 0;
>  }
>  
> +static void uninit_vps(FFRefStructOpaque opaque, void *obj)
> +{
> +    HEVCVPS *vps = obj;
> +
> +    for (int i = 0; i < vps->vps_num_hrd_parameters; i++)
> +        ff_refstruct_unref(&vps->hdr[i]);
> +}
> +
>  int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx,
>                             HEVCParamSets *ps)
>  {
>      int i,j;
>      int vps_id = 0;
>      ptrdiff_t nal_size;
> -    HEVCVPS *vps = ff_refstruct_allocz(sizeof(*vps));
> +    HEVCVPS *vps = ff_refstruct_alloc_ext(sizeof(*vps), 0, NULL, uninit_vps);
>  
>      if (!vps)
>          return AVERROR(ENOMEM);
> @@ -538,12 +546,17 @@ int ff_hevc_decode_nal_vps(GetBitContext *gb, AVCodecContext *avctx,
>              goto err;
>          }
>          for (i = 0; i < vps->vps_num_hrd_parameters; i++) {
> +            HEVCHdrParams *hdr = ff_refstruct_allocz(sizeof(*hdr));
>              int common_inf_present = 1;
>  
> +            if (!hdr)
> +                return AVERROR(ENOMEM);
> +
>              get_ue_golomb_long(gb); // hrd_layer_set_idx
>              if (i)
>                  common_inf_present = get_bits1(gb);
> -            decode_hrd(gb, common_inf_present, &vps->hdr[i],
> +
> +            decode_hrd(gb, common_inf_present, hdr,
>                         vps->vps_max_sub_layers);
>          }

Why do you allocate the HEVCHdrParams separately when you know
vps_num_hrd_parameters before allocating the first one?

>      }
> diff --git a/libavcodec/hevc_ps.h b/libavcodec/hevc_ps.h
> index 9cdec9b6c1..ff94f90a5e 100644
> --- a/libavcodec/hevc_ps.h
> +++ b/libavcodec/hevc_ps.h
> @@ -150,7 +150,7 @@ typedef struct PTL {
>  
>  typedef struct HEVCVPS {
>      unsigned int vps_id;
> -    HEVCHdrParams hdr[HEVC_MAX_LAYER_SETS];
> +    HEVCHdrParams *hdr[HEVC_MAX_LAYER_SETS];
>  
>      uint8_t vps_temporal_id_nesting_flag : 1;
>      uint8_t vps_sub_layer_ordering_info_present_flag : 1;
> diff --git a/libavcodec/vulkan_hevc.c b/libavcodec/vulkan_hevc.c
> index 239bff75e5..a89d09a372 100644
> --- a/libavcodec/vulkan_hevc.c
> +++ b/libavcodec/vulkan_hevc.c
> @@ -563,7 +563,7 @@ static void set_vps(const HEVCVPS *vps,
>                      HEVCHeaderVPSSet sls[])
>  {
>      for (int i = 0; i < vps->vps_num_hrd_parameters; i++) {
> -        const HEVCHdrParams *src = &vps->hdr[i];
> +        const HEVCHdrParams *src = vps->hdr[i];
>  
>          sls_hdr[i] = (StdVideoH265HrdParameters) {
>              .flags = (StdVideoH265HrdFlags) {