Function std::audio_copy_frames

unsigned long audio_copy_frames(
    []unsigned char dst,
    unsigned int dst_format,
    int dst_channels,
    int dst_interleaved,
    int dst_first,
    []const unsigned char src,
    unsigned int src_format,
    int src_channels,
    int src_interleaved,
    int src_first,
    int channels,
    unsigned long frames,
)

The general copy streams use: 'channels' channels of 'frames' frames, from 'src' (src_channels per frame, src_interleaved, src_format, starting at channel src_first) to 'dst' (likewise). Channels of 'dst' outside [dst_first, dst_first + channels) are left untouched. Returns 'frames', or 0 (copying nothing) when a buffer is smaller than frames * its channels samples or the channel ranges don't fit.