linux下使用ffmpeg指令从摄像头中录取视频

深碍√TFBOYSˉ_ 2023-07-15 13:20 20阅读 0赞

# Capture and stream video and audio #

Now, on machine with camera, open *Terminal/command prompt* and run following command to start capturing video and audio and generating live stream to another computer

Windows

ffmpeg -f dshow -i video="Integrated Webcam":audio="Microphone (Realtek Audio)" -profile:v high -pix_fmt yuvj420p -level:v 4.1 -preset ultrafast -tune zerolatency -vcodec libx264 -r 10 -b:v 512k -s 640x360 -acodec aac -ac 2 -ab 32k -ar 44100 -f mpegts -flush_packets 0 udp://192.168.1.4:5000?pkt_size=1316

Linux

On linux, instead of `dshow` ([DirectShow][]), we need to use 2 different drivers for video and audio:

*  video capture - `v4l2` ([Video For Linux drivers][])
 *  audio capture - `alsa` ([ALSA][])

ffmpeg -f v4l2 -i video="Integrated Webcam" -f alsa -i hw:0 -profile:v high -pix_fmt yuvj420p -level:v 4.1 -preset ultrafast -tune zerolatency -vcodec libx264 -r 10 -b:v 512k -s 640x360 -acodec aac -strict -2 -ac 2 -ab 32k -ar 44100 -f mpegts -flush_packets 0 udp://192.168.1.4:5000?pkt_size=1316

> Do not forget to replace video and audio devices names and destination IP address with previously discovered values.

## Options demystified ##

Lets reformat previous command so that we can see used options better

ffmpeg -f dshow \
    -i video="Integrated Webcam":audio="Microphone (Realtek Audio)" \
    -profile:v high -pix_fmt yuvj420p -level:v 4.1 -preset ultrafast -tune zerolatency \
    -vcodec libx264 -r 10 -b:v 512k -s 640x360 \
    -acodec aac -ac 2 -ab 32k -ar 44100 \
    -f mpegts -flush_packets 0 udp://192.168.1.4:5000?pkt_size=1316

*  `-f fshow` - windows system drivers for capturing video and audio
 *  `-f v4l2` - linux system drivers for capturing video
 *  `-f alsa` - linux system drivers for capturing audio
 *  `-i` - ffmpeg option that defines **input**
 *  `-vcodec libx264` - raw video from camera will be encoded using H264 video codec
 *  `-r 10` - video FPS (frames per second)
 *  `-b:v 512k` - video bitrate Kb/s (kilo bits per second)
 *  `-s 640x360` - video width and height
 *  `-acodec aac` - raw audio from microphone will be encoded using AAC audio codec
 *  `-ac 2` - 2 audio channels (stereo)
 *  `-ab 32k` - audio bitrate in Kb/s
 *  `-ar 44100` - audio sampling rate 44.1 KHz
 *  `-f mpegts` - video and audio will be packed into [MPEG transport stream (MPEG TS)][MPEG transport stream _MPEG TS]
 *  `udp://192.168.1.4:5000` - MPEG transport stream is sent via UDP protocol to computer with IP address 192.168.1.4 on IP port 5000.

# Play camera stream #

Windows/Linux

On destination computer stream can be watched using [VLC player][]

*  go to menu Media->Open Network Stream...
 *  in URL field type `udp://@0.0.0.0:5000` and press Play

[DirectShow]: https://en.wikipedia.org/wiki/DirectShow
[Video For Linux drivers]: https://en.wikipedia.org/wiki/Video4Linux
[ALSA]: https://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture
[MPEG transport stream _MPEG TS]: https://en.wikipedia.org/wiki/MPEG_transport_stream
[VLC player]: https://www.videolan.org/vlc/index.html