v4l2_audio
#define VIDIOC_G_AUDIO _IOR('V', 33, struct v4l2_audio)
#define VIDIOC_S_AUDIO _IOW('V', 34, struct v4l2_audio)
#define VIDIOC_ENUMAUDIO _IOWR('V', 65, struct v4l2_audio)
#define VIDIOC_G_AUDIO_OLD _IOWR('V', 33, struct v4l2_audio)