pub unsafe extern "C" fn av_downmix_info_update_side_data(
frame: *mut AVFrame,
) -> *mut AVDownmixInfo展开描述
Get a frame’s AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
If the side data is absent, it is created and added to the frame.
@param frame the frame for which the side data is to be obtained or created
@return the AVDownmixInfo structure to be edited by the caller, or NULL if the structure cannot be allocated.