Re: [PATCH 5/7] winegstreamer: List all video formats with a macro and generate mappings.

[Zebediah Figura]

On 9/27/22 03:32, Rémi Bernon wrote:
> +/* List all supported raw video formats, with their metadata.
> -
> -
> -
> - Each element should be X(wg, guid, depth, type), with:
> -
> - wg: suffix of the GStreamer constant, and enum wg_video_format value.
> -
> - guid: suffix of the corresponding MEDIASUBTYPE / MFVideoFormat guid.
> -
> - depth: the number of bits of each video sample.
> -
> - type: whether the video format is RGB or YUV.
> -
> -
> - */
>
> +#define FOR_EACH_WG_VIDEO_FORMAT(F)  \
> - F(BGRA, ARGB32, 32, RGB)         \
> - F(BGRx, RGB32, 32, RGB)          \
> - F(BGR, RGB24, 24, RGB)           \
> - F(RGB15, RGB555, 16, RGB)        \
> - F(RGB16, RGB565, 16, RGB)        \
> - F(AYUV, AYUV, 32, YUV)           \
> - F(I420, I420, 12, YUV)           \
> - F(NV12, NV12, 12, YUV)           \
> - F(UYVY, UYVY, 16, YUV)           \
> - F(YUY2, YUY2, 16, YUV)           \
> - F(YV12, YV12, 12, YUV)           \
> - F(YVYU, YVYU, 16, YUV)           \
> -
>
> +enum wg_video_format
> +{
> - WG_VIDEO_FORMAT_UNKNOWN = 0,
>
> +#define X(x, g, d, t) WG_VIDEO_FORMAT_ ## x,
> - FOR_EACH_WG_VIDEO_FORMAT(X)
>
> +#undef X
> +};

I don't hate this, but I'm also less than thrilled about it.

One of the nice things about spelling things out explicitly is that it's 
easy for someone unfamiliar with the code to grep for constants to see 
how they're converted.

This also puts some burden on the reader to mentally preprocess the code 
first. It's probably not a big deal, since it's not difficult to 
understand what it's doing, but I'm not really sure it's worthwhile in 
this case.