[FFmpeg-devel] [PATCH] cuvid: support AVCodecContext.hw_device_ctx API

[Philip Langdale]

On 2017-05-02 16:56, wm4 wrote:
> This is a newer API that is intended for decoders like the cuvid
> wrapper. Until now, the wrapper required to set an awkward
> "incomplete" hw_frames_ctx to set the device. Now the device
> can be set directly, and the user can get AV_PIX_FMT_CUDA output
> for a specific device simply by setting hw_device_ctx.
> 
> This still does a dummy ff_get_format() call at init time, and should
> be fully backward compatible.
> ---
> Not sure how to test correctly - it worked with mpv even when I
> accidentally didn't use the correct VO device.
> ---
>  libavcodec/cuvid.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/cuvid.c b/libavcodec/cuvid.c
> index 288083423e..3453003965 100644
> --- a/libavcodec/cuvid.c
> +++ b/libavcodec/cuvid.c
> @@ -802,9 +802,17 @@ static av_cold int 
> cuvid_decode_init(AVCodecContext *avctx)
>              goto error;
>          }
>      } else {
> -        ret = av_hwdevice_ctx_create(&ctx->hwdevice,
> AV_HWDEVICE_TYPE_CUDA, ctx->cu_gpu, NULL, 0);
> -        if (ret < 0)
> -            goto error;
> +        if (avctx->hw_device_ctx) {
> +            ctx->hwdevice = av_buffer_ref(avctx->hw_device_ctx);
> +            if (!ctx->hwdevice) {
> +                ret = AVERROR(ENOMEM);
> +                goto error;
> +            }
> +        } else {
> +            ret = av_hwdevice_ctx_create(&ctx->hwdevice,
> AV_HWDEVICE_TYPE_CUDA, ctx->cu_gpu, NULL, 0);
> +            if (ret < 0)
> +                goto error;
> +        }
> 
>          ctx->hwframe = av_hwframe_ctx_alloc(ctx->hwdevice);
>          if (!ctx->hwframe) {

Makes sense to me. Ship it.

--phil