[FFmpeg-devel] [PATCH] examples/hw_decode: Use hw-config information to find pixfmt

[Jun Zhao]

On 2017/11/29 8:34, Mark Thompson wrote:
> This removes all remaining device-type specificity.
> ---
>  doc/examples/hw_decode.c | 55 ++++++++++++++++++++----------------------------
>  1 file changed, 23 insertions(+), 32 deletions(-)
>
> diff --git a/doc/examples/hw_decode.c b/doc/examples/hw_decode.c
> index 9c7adbf51a..8f48f3b706 100644
> --- a/doc/examples/hw_decode.c
> +++ b/doc/examples/hw_decode.c
> @@ -44,34 +44,6 @@ static AVBufferRef *hw_device_ctx = NULL;
>  static enum AVPixelFormat hw_pix_fmt;
>  static FILE *output_file = NULL;
>  
> -static enum AVPixelFormat find_fmt_by_hw_type(const enum AVHWDeviceType type)
> -{
> -    enum AVPixelFormat fmt;
> -
> -    switch (type) {
> -    case AV_HWDEVICE_TYPE_VAAPI:
> -        fmt = AV_PIX_FMT_VAAPI;
> -        break;
> -    case AV_HWDEVICE_TYPE_DXVA2:
> -        fmt = AV_PIX_FMT_DXVA2_VLD;
> -        break;
> -    case AV_HWDEVICE_TYPE_D3D11VA:
> -        fmt = AV_PIX_FMT_D3D11;
> -        break;
> -    case AV_HWDEVICE_TYPE_VDPAU:
> -        fmt = AV_PIX_FMT_VDPAU;
> -        break;
> -    case AV_HWDEVICE_TYPE_VIDEOTOOLBOX:
> -        fmt = AV_PIX_FMT_VIDEOTOOLBOX;
> -        break;
> -    default:
> -        fmt = AV_PIX_FMT_NONE;
> -        break;
> -    }
> -
> -    return fmt;
> -}
> -
>  static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
>  {
>      int err = 0;
> @@ -184,18 +156,23 @@ int main(int argc, char *argv[])
>      AVCodec *decoder = NULL;
>      AVPacket packet;
>      enum AVHWDeviceType type;
> +    int i;
>  
>      if (argc < 4) {
> -        fprintf(stderr, "Usage: %s <vaapi|vdpau|dxva2|d3d11va> <input file> <output file>\n", argv[0]);
> +        fprintf(stderr, "Usage: %s <device type> <input file> <output file>\n", argv[0]);
>          return -1;
>      }
>  
>      av_register_all();
>  
>      type = av_hwdevice_find_type_by_name(argv[1]);
> -    hw_pix_fmt = find_fmt_by_hw_type(type);
> -    if (hw_pix_fmt == -1) {
> -        fprintf(stderr, "Cannot support '%s' in this example.\n", argv[1]);
> +    if (type == AV_HWDEVICE_TYPE_NONE) {
> +        fprintf(stderr, "Device type %s is not supported.\n", argv[1]);
> +        fprintf(stderr, "Available device types:");
> +        type = AV_HWDEVICE_TYPE_NONE;
> +        while((type = av_hwdevice_iterate_types(type)) != AV_HWDEVICE_TYPE_NONE)
> +            fprintf(stderr, " %s", av_hwdevice_get_type_name(type));
> +        fprintf(stderr, "\n");
>          return -1;
>      }
>  
> @@ -218,6 +195,20 @@ int main(int argc, char *argv[])
>      }
>      video_stream = ret;
>  
> +    for (i = 0;; i++) {
> +        const AVCodecHWConfig *config = avcodec_get_hw_config(decoder, i);
> +        if (!config) {
> +            fprintf(stderr, "Decoder %s does not support device type %s.\n",
> +                    decoder->name, av_hwdevice_get_type_name(type));
> +            return -1;
> +        }
> +        if (config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX &&
> +            config->device_type == type) {
> +            hw_pix_fmt = config->pix_fmt;
> +            break;
> +        }
> +    }
> +
>      if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
>          return AVERROR(ENOMEM);
>  
LGTM and tesed