[book club issue 13] +ffmpeg video capture function

FFmpeg Video capture is very powerful , Not only can you capture video capture cards or USB The camera image , You can also do screen recording , At the same time, we also support RTP How to spread the video to support RTSP Streaming media server , Support live applications .

stay windows Next about ffmpeg There is very little information collected from the video , however ffmpeg Or support windows Next video capture .ffmpeg Support windows Next video for windows(VFW) Video capture of the device , however VFW The device is out of date , Is being WDM Instead of video devices , however ffmpeg There is no support for WDM The plan for , But it seems that there will be WDM To VFW Tools for , therefore ffmpeg It can still be done in windows The next video capture .

collection 10 Second video , Yes video4linux2 Video equipment to capture , collection QCIF(176*144) In the video , Per second 8 frame , The video device is /dev/video0, The video is encoded as H263, The output format is RTP, It's defined later IP Address and port , The bit stream corresponding to SDP File redirection to /tmp/ffmpeg.sdp in , Put this SDP The files can be uploaded to the streaming media server to realize live broadcast .