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• How can I encode a video to play on a DLink DSM-520 using FFMPEG ?

  17 octobre 2020, par tolsen64

  I have been searching, testing, and coming up with nothing for over a week. I want to use FFMPEG to convert mp4's and mkv's to AVI files that will play on my DLink DSM-520. Mencoder will do it. The files that FFMPEG generates cause the player to lock up less than a minute into the video. First, here's what I use to encode the file using Mencoder (scraped from the test.bat file that PocketDIVXEncoder generates :

  



  mencoder.exe ftwd105.mp4 -af volnorm -srate 44100 -oac mp3lame -lameopts mode=0:cbr:br=128 -noodml -vf pp=ac,scale=720:404,crop=720:400,harddup -sws 9 -ovc lavc -lavcopts vcodec=mpeg4:mbd=1:last_pred=2:vstrict=1:threads=2:vmax_b_frames=0:vbitrate=1200 -ffourcc XVID -o ftwd105_HDTV.avi


  



  The output file plays perfectly on the DSM-520. Looking at the file using FFPROBE, I see this :

  



  Input #0, avi, from 'ftwd105_HDTV.avi':
  Metadata:
    encoder         : MEncoder Redxii-SVN-r37527-4.9.3 (x86_64)
  Duration: 00:44:32.96, start: 0.000000, bitrate: 1193 kb/s
    Stream #0:0: Video: mpeg4 (Simple Profile) (XVID / 0x44495658), yuv420p, 720x400 [SAR 1:1 DAR 9:5], 1053 kb/s, 23.98 fps, 23.98 tbr, 23.98 tbn, 24k tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 44100 Hz, stereo, s16p, 128 kb/s


  



  So now I try the same thing with FFMPEG.

  



  ffmpeg -i ftwd105.mp4 -vcodec mpeg4 -vtag XVID -b:v 1200k -s 720x400 -acodec libmp3lame -ab 128k -ar 44100 -ac 2 -f avi ftwd105_ffmpeg.avi


  



  This file does not play on the media player. It plays choppy with only clicking for sound for about 15-30 seconds, then it freezes. Looking at it with FFPROBE, it looks exactly the same as the one created by Mencoder.

  



  Input #0, avi, from 'ftwd105_ffmpeg.avi':
  Metadata:
    encoder         : Lavf57.0.100
  Duration: 00:44:33.14, start: 0.000000, bitrate: 1305 kb/s
    Stream #0:0: Video: mpeg4 (Simple Profile) (XVID / 0x44495658), yuv420p, 720x400 [SAR 1:1 DAR 9:5], 1165 kb/s, 23.98 fps, 23.98 tbr, 23.98 tbn, 24k tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 44100 Hz, stereo, s16p, 128 kb/s


  



  So now I encode the video using Xvid4PSP. It plays perfectly fine and FFPROBE shows this :

  



  Input #0, avi, from 'ftwd105_ps2.avi':
  Metadata:
    encoder         : VirtualDubMod 1.5.10.3 | www.virtualdub-fr.org || (build 2550/release)
  Duration: 00:44:33.09, start: 0.000000, bitrate: 861 kb/s
    Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 720x400 [SAR 1:1 DAR 9:5], 723 kb/s, 23.98 fps, 23.98 tbr, 23.98 tbn, 23.98 tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16p, 128 kb/s


  



  It's using Advanced Simple Profile so I look this up and change my FFMPEG options :

  



  ffmpeg -i ftwd105.mp4 -vcodec mpeg4 -vtag XVID -b:v 1200k -s 720x400 -profile:v 15 -level 0 -acodec libmp3lame -ab 128k -ar 44100 -ac 2 -f avi ftwd105_ffmpeg.avi


  



  But though the output file looks the same using FFPROBE as the one made by Xvid4PSP, it still doesn't play on the DSM-520.

  



  Input #0, avi, from 'ftwd105_ffmpeg_asp.avi':
  Metadata:
    encoder         : Lavf57.0.100
  Duration: 00:44:33.14, start: 0.000000, bitrate: 1305 kb/s
    Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 720x400 [SAR 1:1 DAR 9:5], 1165 kb/s, 23.98 fps, 23.98 tbr, 23.98 tbn, 24k tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 44100 Hz, stereo, s16p, 128 kb/s


  



  So now i'm at a loss. Is FFMPEG incapable of generating a file that the DSM-520 can play ? The reason I want to use FFMPEG over Mencoder is that it's much faster. What takes FFMPEG 15 minutes takes Mencoder 40.

  



  I should note that all the files created by FFMPEG play fine on the PC and on my Visio television. The DSM-520 is hooked up to a bedroom tv that isn't a smart tv.

  



  Edit : I also tried libxvid in place of mpeg4 with the same results.

  


• How can I correctly provide a mock webcam video to Chrome ?

  15 décembre 2022, par doppelgreener

  I'm trying to run end-to-end testing in Chrome for a product that requires a webcam feed halfway through to operate. From what I understand this means providing a fake webcam video to Chrome using the --use-file-for-fake-video-capture="/path/to/video.y4m" command line argument. It will then use that as a webcam video.

  



  However, no matter what y4m file I provide, I get the following error from Chrome running under these conditions :

  



  DOMException: Could not start video source
{
  code: 0,
  message: "Could not start video source",
  name: "NotReadableError"
}


  



  Notably I can provide an audio file just fine using --use-file-for-fake-audio-capture and Chrome will work with it well. The video has been my sticking point.

  



  This error comes out of the following straightforward mediaDevices request :

  



  navigator.mediaDevices.getUserMedia({ video: true, audio: true })
  .then(data => {
    // do stuff
  })
  .catch(err => {
    // oh no!
  });


  



  (This always hits the “oh no !” branch when a video file is provided.)

  



  What I've tried so far

  



  I've been running Chrome with the following command line arguments (newlines added for readability), and I'm using a Mac hence the open command :

  





  open -a "Google Chrome" --args
  --disable-gpu
  --use-fake-device-for-media-stream
  --use-file-for-fake-video-capture="~/Documents/mock/webcam.y4m"
  --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"


  



  webcam.y4m and microphone.wav were generated from a video file I recorded.

  



  I first recorded a twenty-second mp4 video using my browser's MediaRecorder, downloaded the result, and converted it using the following command line commands :

  



  ffmpeg -y -i original.mp4 -f wav -vn microphone.wav
ffmpeg -y -i original.mp4 webcam.y4m


  



  When this didn't work, I tried the same using a twenty-second movie file I recorded in Quicktime :

  



  ffmpeg -y -i original.mov -f wav -vn microphone.wav
ffmpeg -y -i original.mov webcam.y4m


  



  When that also failed, I went straight to the Chromium file that explains fake video capture, went to the example y4m file list it provided, and downloaded the grandma file and provided that as a command line argument to Chrome instead :

  



  open -a "Google Chrome" --args
  --disable-gpu
  --use-fake-device-for-media-stream
  --use-file-for-fake-video-capture="~/Documents/mock/grandma_qcif.y4m"
  --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"


  



  Chrome provides me with the exact same error in all of these situations.

  



  The only time Chrome doesn't error out with that mediaDevices request is when I omit the video completely :

  



  open -a "Google Chrome" --args
  --disable-gpu
  --use-fake-device-for-media-stream
  --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"


  



  Accounting for C420mpeg2

  



  TestRTC suggests Chrome will “crash” if I give it a C420mpeg2 file, and recommends that simply replacing the metadata fixes the issue. Indeed the video file I generate from ffmpeg gives me the following header :

  



  YUV4MPEG2 W1280 H720 F30:1 Ip A1:1 C420mpeg2 XYSCSS=420MPEG2


  



  Chrome doesn't actually crash when run with this file, I just get the error above. If I edit the video file to the following header though per TestRTC's recommendations I get the same situation :

  



  YUV4MPEG2 W1280 H720 F30:1 Ip A1:1 C420 XYSCSS=420MPEG2


  



  The video file still gives me the above error in these conditions.

  



  What can/should I do ?

  



  How should I be providing a video file to Chrome for this command line argument ?

  



  How should I be recording or creating the video file ?

  



  How should I convert it to y4m ?

  


• How can I correctly provide a fake webcam input to Chrome ?

  30 août 2018, par doppelgreener

  I’m trying to run end-to-end testing in Chrome for a product that requires a webcam feed halfway through to operate. From what I understand this means providing a fake webcam video to Chrome using the --use-file-for-fake-video-capture="/path/to/video.y4m" command line argument. It will then use that as a webcam video.

  However, no matter what y4m file I provide, I get the following error from Chrome running under these conditions :

  DOMException: Could not start video source
  
  {
  
    code: 0,
  
    message: "Could not start video source",
  
    name: "NotReadableError"
  
  }

  Notably I can provide an audio file just fine using --use-file-for-fake-audio-capture and Chrome will work with it well. The video has been my sticking point.

  This error comes out of the following straightforward mediaDevices request :

  navigator.mediaDevices.getUserMedia({ video: true, audio: true })
  
    .then(data => {
  
      // do stuff
  
    })
  
    .catch(err => {
  
      // oh no!
  
    });

  (This always hits the “oh no !” branch when a video file is provided.)

  What I’ve tried so far

  I’ve been running Chrome with the following command line arguments (newlines added for readability), and I’m using a Mac hence the open command :

  open -a "Google Chrome" --args
  
    --disable-gpu
  
    --use-fake-device-for-media-stream
  
    --use-file-for-fake-video-capture="~/Documents/mock/webcam.y4m"
  
    --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"

  webcam.y4m and microphone.wav were generated from a video file I recorded.

  I first recorded a twenty-second mp4 video using my browser’s MediaRecorder, downloaded the result, and converted it using the following command line commands :

  ffmpeg -y -i original.mp4 -f wav -vn microphone.wav
  
  ffmpeg -y -i original.mp4 webcam.y4m

  When this didn’t work, I tried the same using a twenty-second movie file I recorded in Quicktime :

  ffmpeg -y -i original.mov -f wav -vn microphone.wav
  
  ffmpeg -y -i original.mov webcam.y4m

  When that also failed, I went straight to the Chromium file that explains fake video capture, went to the example y4m file list it provided, and downloaded the grandma file and provided that as a command line argument to Chrome instead :

  open -a "Google Chrome" --args
  
    --disable-gpu
  
    --use-fake-device-for-media-stream
  
    --use-file-for-fake-video-capture="~/Documents/mock/grandma_qcif.y4m"
  
    --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"

  Chrome provides me with the exact same error in all of these situations.

  The only time Chrome doesn’t error out with that mediaDevices request is when I omit the video completely :

  open -a "Google Chrome" --args
  
    --disable-gpu
  
    --use-fake-device-for-media-stream
  
    --use-file-for-fake-audio-capture="~/Documents/mock/microphone.wav"

  Accounting for C420mpeg2

  TestRTC suggests Chrome will “crash” if I give it a C420mpeg2 file, and recommends that simply replacing the metadata fixes the issue. Indeed the video file I generate from ffmpeg gives me the following header :

  YUV4MPEG2 W1280 H720 F30:1 Ip A1:1 C420mpeg2 XYSCSS=420MPEG2

  Chrome doesn’t actually crash when run with this file, I just get the error above. If I edit the video file to the following header though per TestRTC’s recommendations I get the same situation :

  YUV4MPEG2 W1280 H720 F30:1 Ip A1:1 C420 XYSCSS=420MPEG2

  The video file still gives me the above error in these conditions.

  What can/should I do ?

  How should I be providing a video file to Chrome for this command line argument ?

  How should I be recording or creating the video file ?

  How should I convert it to y4m ?