[FFmpeg-devel] [PATCH v2 1/3] avutil/hwcontext: add a function to get the AVHWDeviceType

[Anton Khirnov]

Quoting Tong Wu (2022-06-30 04:45:56)
> Add a function to get the corresponding AVHWDeviceType from a given
> hardware pixel format.
> 
> Signed-off-by: Tong Wu <tong1.wu at intel.com>
> ---
>  libavutil/hwcontext.c | 12 ++++++++++++
>  libavutil/hwcontext.h |  9 +++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/libavutil/hwcontext.c b/libavutil/hwcontext.c
> index ab9ad3703e..3521ed34f4 100644
> --- a/libavutil/hwcontext.c
> +++ b/libavutil/hwcontext.c
> @@ -80,6 +80,18 @@ static const char *const hw_type_names[] = {
>      [AV_HWDEVICE_TYPE_VULKAN] = "vulkan",
>  };
>  
> +enum AVHWDeviceType av_hwdevice_get_type_by_pix_fmt(enum AVPixelFormat fmt)
> +{
> +    int i, j;

Nit: you can and should declare loop indices in the loop statement
itself

> +    for (i = 0; hw_table[i]; i++) {
> +        for (j = 0; hw_table[i]->pix_fmts[j] != AV_PIX_FMT_NONE; j++) {
> +            if (hw_table[i]->pix_fmts[j] == fmt)
> +                return hw_table[i]->type;
> +        }
> +    }
> +    return AV_HWDEVICE_TYPE_NONE;
> +}
> +
>  enum AVHWDeviceType av_hwdevice_find_type_by_name(const char *name)
>  {
>      int type;
> diff --git a/libavutil/hwcontext.h b/libavutil/hwcontext.h
> index c18b7e1e8b..97f94403e2 100644
> --- a/libavutil/hwcontext.h
> +++ b/libavutil/hwcontext.h
> @@ -229,6 +229,15 @@ typedef struct AVHWFramesContext {
>      int width, height;
>  } AVHWFramesContext;
>  
> +/**
> + * Get the device type by a given pixel format.
> + *
> + * @param fmt Pixel format from enum AVPixelFormat.
> + * @return The type from enum AVHWDeviceType, or AV_HWDEVICE_TYPE_NONE if
> + *         not found.
> + */
> +enum AVHWDeviceType av_hwdevice_get_type_by_pix_fmt(enum AVPixelFormat fmt);

I wonder if we should consider the possibility of a format being
supported by more than one device type.

-- 
Anton Khirnov