[FFmpeg-devel] [PATCH 001/279] Add a new channel layout API

[Lynne]

8 Dec 2021, 02:06 by jamrial at gmail.com:

>  
> +enum AVChannel {
> +    ///< Invalid channel index
> +    AV_CHAN_NONE = -1,
> +    AV_CHAN_FRONT_LEFT,
>

No, not the pixfmt mistake again. Set AV_CHAN_NONE to 0,
the rest can follow. Or keep AV_CHAN_NONE to -1
and add a new AV_CHAN_UNSPECIFIED as 0.


> +    AV_CHAN_FRONT_RIGHT,
> +    AV_CHAN_FRONT_CENTER,
> +    AV_CHAN_LOW_FREQUENCY,
> +    AV_CHAN_BACK_LEFT,
> +    AV_CHAN_BACK_RIGHT,
> +    AV_CHAN_FRONT_LEFT_OF_CENTER,
> +    AV_CHAN_FRONT_RIGHT_OF_CENTER,
> +    AV_CHAN_BACK_CENTER,
> +    AV_CHAN_SIDE_LEFT,
> +    AV_CHAN_SIDE_RIGHT,
> +    AV_CHAN_TOP_CENTER,
> +    AV_CHAN_TOP_FRONT_LEFT,
> +    AV_CHAN_TOP_FRONT_CENTER,
> +    AV_CHAN_TOP_FRONT_RIGHT,
> +    AV_CHAN_TOP_BACK_LEFT,
> +    AV_CHAN_TOP_BACK_CENTER,
> +    AV_CHAN_TOP_BACK_RIGHT,
> +    /** Stereo downmix. */
> +    AV_CHAN_STEREO_LEFT = 29,
> +    /** See above. */
> +    AV_CHAN_STEREO_RIGHT,
> +    AV_CHAN_WIDE_LEFT,
> +    AV_CHAN_WIDE_RIGHT,
> +    AV_CHAN_SURROUND_DIRECT_LEFT,
> +    AV_CHAN_SURROUND_DIRECT_RIGHT,
> +    AV_CHAN_LOW_FREQUENCY_2,
> +    AV_CHAN_TOP_SIDE_LEFT,
> +    AV_CHAN_TOP_SIDE_RIGHT,
> +    AV_CHAN_BOTTOM_FRONT_CENTER,
> +    AV_CHAN_BOTTOM_FRONT_LEFT,
> +    AV_CHAN_BOTTOM_FRONT_RIGHT,
> +
> +    /** Channel is empty can be safely skipped. */
> +    AV_CHAN_SILENCE = 64,
> +};
>

Why is AV_CHAN_SILENCE set to 64? If it's special,
set it to follow just after AV_CHAN_NONE or
AV_CHAN_UNSPECIFIED.

Finally, consider adding an AV_CHAN_NB at
the end, not part of the API, for jut in case.