pub unsafe extern "C" fn avdevice_dev_to_app_control_message(
    s: *mut AVFormatContext,
    type_: AVDevToAppMessageType,
    data: *mut c_void,
    data_size: usize
) -> c_int
Expand description

Send control message from device to application.

@param s device context. @param type message type. @param data message data. Can be NULL. @param data_size size of message data. @return >= 0 on success, negative on error. AVERROR(ENOSYS) when application doesn’t implement handler of the message.