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• Problem with combining a video and an audio stream from USB device

  3 février 2020, par FHoevi

  I have two USB devices attached to an RPi, both show up as usual as /dev/video0. Here’s some additional info coming from two command line inputs :

  Device 1, video only (attached to an RPi4) :

  ffmpeg -f v4l2 -list_formats all -i /dev/video0 reports

  [video4linux2,v4l2 @ 0xe5e1c0] Compressed:       mjpeg :
  
  Motion-JPEG : 1280x720 640x480 320x240

  v4l2-ctl --list-formats-ext reports

  ioctl: VIDIOC_ENUM_FMT
  
          Type: Video Capture
  
          [0]: 'MJPG' (Motion-JPEG, compressed)
  
                  Size: Discrete 1280x720
  
                          Interval: Stepwise 0.033s - 0.033s with step 0.000s
  
  (30.000-30.000 fps)
  
                  Size: Discrete 640x480
  
                          Interval: Stepwise 0.033s - 0.033s with step 0.000s
  
  (30.000-30.000 fps)
  
                  Size: Discrete 320x240
  
                          Interval: Stepwise 0.033s - 0.033s with step 0.000s
  
  (30.000-30.000 fps)

  Does work : ffmpeg -f v4l2 -i /dev/video0 -vcodec h264_omx -preset ultrafast -tune zerolatency -g 300 -b:v 1M -mpegts_service_type advanced_codec_digital_hdtv -f mpegts udp://OtherMachine:Port?pkt_size=1316

  Device 2, video and audio (attached to an RPi3, but does not work either on the RPi4) :

  ffmpeg -f v4l2 -list_formats all -i /dev/video0 reports

  [video4linux2,v4l2 @ 0x2c41210] Compressed:       mjpeg :
  
  Motion-JPEG : 1920x1080 1280x720

  v4l2-ctl --list-formats-ext reports

  ioctl: VIDIOC_ENUM_FMT
  
                 Index       : 0
  
                 Type        : Video Capture
  
                 Pixel Format: 'MJPG' (compressed)
  
                 Name        : Motion-JPEG
  
                                Size: Discrete 1920x1080
  
                                              Interval: Discrete 0.033s
  
  (30.000 fps)
  
                                              Interval: Discrete 0.067s
  
  (15.000 fps)
  
                                Size: Discrete 1280x720
  
                                              Interval: Discrete 0.033s
  
  (30.000 fps)
  
                                              Interval: Discrete 0.067s
  
  (15.000 fps)

  After quite some tedious work and way too many hours I got this running :

  Video only : ffmpeg -f v4l2 -input_format mjpeg -i /dev/video0 -c:v copy -preset ultrafast -tune zerolatency -g 300 -f matroska udp://OtherMachine:Port?pkt_size=1316

  Does not work at all : ffmpeg -f v4l2 -input_format mjpeg -i /dev/video0 -c:v copy -preset ultrafast -tune zerolatency -g 300 -f mpegts udp://OtherMachine:Port?pkt_size=1316, on "OtherMachine" I do see that there is an incoming data stream via VLC, but it could not be digested properly.

  Audio only : ffmpeg -f alsa -thread_queue_size 1024 -i plughw:1 -c:a mp2 -ac 2 -ar 44100 -preset ultrafast -tune zerolatency -b:a 128K -f mpegts udp://OtherMachine:Port?pkt_size=1316

  But this does not work either :

  ffmpeg -f v4l2 -input_format mjpeg -i /dev/video0 -f alsa -thread_queue_size
1024 -i plughw:1 -c:v copy -c:a mp2 -ac 2 -ar 44100 -preset ultrafast -tune zerolatency -g 300  -b:a 128K -f mpegts udp://OtherMachine:Port?pkt_size=1316

  Could you please provide a hint on how to get these two streams for device 2 working together ? Both of them come from the same hardware/device, my guess is that the MJPG video stream is somehow not fully compliant with the mpegts standard (like it is for device 1) since it works with matroska, but not with mpegts. Could that be ? What needs to be done in that case ?

  Another hint, with the same kind of hardware setup I can do this

  cvlc -vvv v4l2:///dev/video0 --input-slave=alsa://plughw:1,0 --sout='#transcode{acodec=mpga,ab=128}:std{access=http,mux=asf,dst=:Port}'

  So, here my understanding is that video gets passed on unchanged (mjpeg) and audio gets transcoded via vlc’s mpga which presumably corresponds to mp2 for ffmpeg. The container format is asf, but I was not able to get that running with ffmpeg for no obvious reason. Anyway, picking up this vlc broadcast stream via http://StreamingMachine:Port on any other machine in my network is working well. But how to achieve that with ffmpeg directly and potentially not as http:// but udp :// or pipe stream ?

  Alternatively, let me ask this question : Given that I have an incoming mjpeg video stream as well as an incoming mp2 audio stream which kind of container format (ok, it’s obviously not mpegts) is the most appropriate one for combined streaming across my LAN or even into a pipe for further processing ? Believe me, I tried my very best over a couple of hours to find out how to proceed but with no success. At least to my humble knowledge there is nothing such like a table providing answers to questions of that kind.

  I’d be glad to get some insights.

  Best

• how to restream rtsp h264 as "live dvr" for iOs using ffserver ?

  18 mai 2017, par mojovski

  I would like to grab an existing stream from an IP-Camera delivering h264 encoded rtsp stream and restream it for iPhone/Ipad, where the user would have the opportunity to jump back in time for aprox. 1 minute. And later jump back to the "live" feed.

  Actually I would like to do the same as in wowza (http://www.wowza.com/addons/wowza-ndvr-addon) but with ff** software.

  Thank you for all your hints !

• Revision 5b76018057 : Merge "Added highbitdepth sse2 SAD acceleration and tests" into highbitdepth

  20 octobre 2014, par Alex Converse

  Changed Paths :
   Modify /vp9/common/vp9_rtcd_defs.pl

  
  
  Merge "Added highbitdepth sse2 SAD acceleration and tests" into highbitdepth