Function av_channel_layout_retype

pub unsafe extern "C" fn av_channel_layout_retype(
    channel_layout: *mut AVChannelLayout,
    order: u32,
    flags: i32,
) -> i32

Change the AVChannelOrder of a channel layout.

Change of AVChannelOrder can be either lossless or lossy. In case of a lossless conversion all the channel designations and the associated channel names (if any) are kept. On a lossy conversion the channel names and channel designations might be lost depending on the capabilities of the desired AVChannelOrder. Note that some conversions are simply not possible in which case this function returns AVERROR(ENOSYS).

The following conversions are supported:

Any -> Custom : Always possible, always lossless. Any -> Unspecified: Always possible, lossless if channel designations are all unknown and channel names are not used, lossy otherwise. Custom -> Ambisonic : Possible if it contains ambisonic channels with optional non-diegetic channels in the end. Lossy if the channels have custom names, lossless otherwise. Custom -> Native : Possible if it contains native channels in native order. Lossy if the channels have custom names, lossless otherwise.

On error this function keeps the original channel layout untouched.

@param channel_layout channel layout which will be changed @param order the desired channel layout order @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants @return 0 if the conversion was successful and lossless or if the channel layout was already in the desired order >0 if the conversion was successful but lossy AVERROR(ENOSYS) if the conversion was not possible (or would be lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified) AVERROR(EINVAL), AVERROR(ENOMEM) on error