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1.9. User Controls — The Linux Kernel documentation
https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/control.html
V4L2_CID_AUDIO_TREBLE (integer) Audio treble adjustment. V4L2_CID_AUDIO_MUTE (boolean) Mute audio, i. e. set the volume to zero, however without affecting V4L2_CID_AUDIO_VOLUME. Like ALSA drivers, V4L2 drivers must mute at load time to avoid excessive noise. Actually the entire device should be reset to a low power consumption state. V4L2_CID ...
Documentation:Modules/v4l2 - VideoLAN Wiki
https://wiki.videolan.org/Documentation:Modules/v4l2/
These options do not apply to audio streams in compressed data. v4l2-adev < string > : Audio input device default value: "". v4l2-audio-method < integer > : Allowed audio input methods (bitmask: 1 for OSS, 2 for ALSA) default value: 3. v4l2-stereo : Capture audio in stereo default value: enabled. v4l2-samplerate < integer > : Audio input sample ...
linux - Can v4l2 be used to read audio and video from the ...
https://stackoverflow.com/questions/917060/can-v4l2-be-used-to-read-audio-and-video-from-the-same-device
Most of the cheap v4l2 capture card's audio is only an analog pass through with a volume control requiring a jumper to capture the audio via the sound card's line input. Share. Improve this answer. Follow answered Dec 24 '09 at 19:53. wkulecz wkulecz. 1 1 1 bronze badge.
7.1. Differences between V4L and V4L2 — The Linux …
https://www.kernel.org/doc/html/v4.9/media/uapi/v4l/diff-v4l.html
To determine which of these controls are supported by a driver V4L provides the flags VIDEO_AUDIO_VOLUME, VIDEO_AUDIO_BASS, VIDEO_AUDIO_TREBLE and VIDEO_AUDIO_BALANCE. In the V4L2 API the ioctls VIDIOC_QUERYCTRL, VIDIOC_QUERY_EXT_CTRL and VIDIOC_QUERYMENU ioctl reports if the respective control is …
New V4L2 control infrastructure [LWN.net]
https://lwn.net/Articles/399547/
For example, if you have to find a volume control from a subdev. You can do that by calling v4l2_ctrl_find: struct v4l2_ctrl *volume; volume = v4l2_ctrl_find(sd->ctrl_handler, V4L2_CID_AUDIO_VOLUME); Since v4l2_ctrl_find will lock the handler you have to be careful where you use it.
1.12. V4L2 Controls — The Linux Kernel documentation
https://www.kernel.org/doc/html/v4.10/media/kapi/v4l2-controls.html
V4L2 Controls — The Linux Kernel documentation. 1.12. V4L2 Controls. ¶. 1.12.1. Introduction. ¶. The V4L2 control API seems simple enough, but quickly becomes very hard to implement correctly in drivers. But much of the code needed to handle controls is actually not driver specific and can be moved to the V4L core framework.
Jetson Linux API Reference: C:/Jenkins/workspace/doxy_l4t ...
https://docs.nvidia.com/jetson/l4t-multimedia/v4l2-controls_8h.html
#define V4L2_CID_AUDIO_VOLUME (V4L2_CID_BASE+5) Definition at line 62 of file v4l2-controls.h. #define V4L2_CID_AUTO_EXPOSURE_BIAS (V4L2_CID_CAMERA_CLASS_BASE+19) Definition at line 683 of file v4l2-controls.h. #define V4L2_CID_AUTO_FOCUS_RANGE (V4L2_CID_CAMERA_CLASS_BASE+31) ...
ioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO
http://v4l-test.sourceforge.net/spec/r9539.htm
V4L2_AUDCAP_STEREO: 0x00001: This is a stereo input. The flag is intended to automatically disable stereo recording etc. when the signal is always monaural. The API provides no means to detect if stereo is received, unless the audio input belongs to a tuner. V4L2_AUDCAP_AVL: 0x00002: Automatic Volume Level mode is supported.
Ubuntu – VLC is unable to open the MRL ‘file:///dev/video0 ...
https://itectec.com/superuser/ubuntu-vlc-is-unable-to-open-the-mrl-file-dev-video0-check-the-log-for-details/
qt debug: item v4l2-color-effect. qt debug: item v4l2-audio-volume. qt debug: item v4l2-audio-balance. qt debug: item v4l2-audio-mute. qt debug: item v4l2-audio-bass. qt debug: item v4l2-audio-treble. qt debug: item v4l2-audio-loudness. qt debug: item v4l2-set-ctrls. main debug: processing request item: v4l2:///dev/video1, node: Playlist, skip: 0
[v4,2/6] drivers:staging: ti-st: fmdrv_v4l2 sources ...
diff --git a/drivers/staging/ti-st/fmdrv_v4l2.c b/drivers/staging/ti-st/fmdrv_v4l2.c new file mode 100644 index 0000000..687d10f--- /dev/null +++ b/drivers/staging/ti ...
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