[FFmpeg-devel] [PATCH 2/2] avcodec/nvdec: make explicit copy of frames unless user requested otherwise

[Philip Langdale]

On Mon,  5 Dec 2022 23:25:59 +0100
Timo Rothenpieler <timo at rothenpieler.org> wrote:

> ---
>  libavcodec/nvdec.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/nvdec.c b/libavcodec/nvdec.c
> index fbaedf0b6b..76ee395734 100644
> --- a/libavcodec/nvdec.c
> +++ b/libavcodec/nvdec.c
> @@ -51,6 +51,8 @@ typedef struct NVDECDecoder {
>  
>      CudaFunctions *cudl;
>      CuvidFunctions *cvdl;
> +
> +    int minimize_copies;
>  } NVDECDecoder;
>  
>  typedef struct NVDECFramePool {
> @@ -344,6 +346,8 @@ int ff_nvdec_decode_init(AVCodecContext *avctx)
>      int cuvid_codec_type, cuvid_chroma_format, chroma_444;
>      int ret = 0;
>  
> +    int minimize_copies = !!(avctx->hwaccel_flags &
> AV_HWACCEL_FLAG_MINIMIZE_COPIES); +
>      sw_desc = av_pix_fmt_desc_get(avctx->sw_pix_fmt);
>      if (!sw_desc)
>          return AVERROR_BUG;
> @@ -402,7 +406,7 @@ int ff_nvdec_decode_init(AVCodecContext *avctx)
>      params.CodecType           = cuvid_codec_type;
>      params.ChromaFormat        = cuvid_chroma_format;
>      params.ulNumDecodeSurfaces = frames_ctx->initial_pool_size;
> -    params.ulNumOutputSurfaces = frames_ctx->initial_pool_size;
> +    params.ulNumOutputSurfaces = minimize_copies ?
> frames_ctx->initial_pool_size : 1; 
>      ret = nvdec_decoder_create(&ctx->decoder_ref,
> frames_ctx->device_ref, &params, avctx); if (ret < 0) {
> @@ -417,6 +421,7 @@ int ff_nvdec_decode_init(AVCodecContext *avctx)
>      }
>  
>      decoder = (NVDECDecoder*)ctx->decoder_ref->data;
> +    decoder->minimize_copies = minimize_copies;
>      decoder->real_hw_frames_ref = real_hw_frames_ref;
>      real_hw_frames_ref = NULL;
>  
> @@ -554,7 +559,11 @@ copy_fail:
>  
>  finish:
>      CHECK_CU(decoder->cudl->cuCtxPopCurrent(&dummy));
> -    return ret;
> +
> +    if (ret < 0 || decoder->minimize_copies)
> +        return ret;
> +
> +    return av_frame_make_writable(frame);
>  }
>  
>  int ff_nvdec_start_frame(AVCodecContext *avctx, AVFrame *frame)

LGTM.


--phil