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• How to stream H.264 bitstream to browser

  21 janvier 2019, par BobtheMagicMoose

  This is a followup to https://raspberrypi.stackexchange.com/questions/93254/stream-usb-webcam-with-audio?noredirect=1#comment150507_93254

  I, like many other brave tinkerers before me, thought it would be a simple task to take an old USB camera (c920) can pair it with a raspberry pi to make a network streaming device (e.g., baby monitor). As those that have gone before me, I have now realized (after two days of tearing my hair out), that this is an extremely complicated task.

  Problem statement : I have a raspberry pi zero and a c920 webcam. I want to use the H.264 bitstream from the webcam and serve it on the pi without transcoding it (the feeble processor would really struggle). I want to combine the video stream with its audio and send it over to a browser (phone, tablet, pc - something HTML5 without NAPI).

  My current strategy is to do the following :

  ffmpeg -re -f s16le -i /dev/zero -f v4l2 -thread_queue_size 512 -codec:v h264 -s 1920x1080 -i /dev/video0 -codec:v copy -acodec aac -ab 128k -g 50 http://localhost:8090/camera.ffm (this is with dummy audio - I figured I would add audio later)

  Followed by sudo ffserver -d -f /etc/ffserver.conf to received the feed and broadcast it as a stream. This is the ffserver.conf file :

  `HTTPPort 8090
  
  HTTPBindAddress 0.0.0.0
  
  MaxHTTPConnections 2000
  
  MaxClients 1000
  
  MaxBandwidth 100000
  
  CustomLog -
  
  <feed>
  
    File /tmp/streamwebm.ffm
  
    FileMaxSize 50M
  
    ACL allow localhost
  
    ACL allow 128.199.149.46
  
    #ACL allow 127.0.0.1
  
    ACL allow 192.168.0.0 192.168.0.255
  
  </feed>
  
  <stream stream="stream">
  
  Format webm
  
  
  
  # Video Settings
  
  VideoFrameRate 30
  
  VideoSize 1920x1080
  
  
  
  # Audio settings
  
  AudioCodec libvorbis
  
  AudioSampleRate 48000
  
  AVOptionAudio flags +global_header
  
  
  
  MaxTime 0
  
  AVOptionVideo me_range 16
  
  AVOptionVideo qdiff 4
  
  AVOptionVideo qmin 4
  
  AVOptionVideo qmax 40
  
  #AVOptionVideo good
  
  AVOptionVideo flags +global_header
  
  
  
  # Streaming settings
  
  PreRoll 10
  
  StartSendOnKey
  
  
  
  Metadata author "author"
  
  Metadata copyright "copyright"
  
  Metadata title "Web app name"
  
  Metadata comment "comment"
  
  </stream>

  My basic html is<video>  <source src="http://localhost:8090/stream"> </source></video>

  The stream however, doesn’t work (the browser won’t connect) and I get the following :
  

  And the browser on the client says (failed) NET::ERR_CONNECTION_REFUSED

  Thoughts :
   Begin stream simple mp4 with ffserver explains that ffserver can’t stream .mp4 because of headers or something. This is why I am using webm (which doesn’t support h.264 I believe and is causing the really slow performance converting to vp9). I’m not concerned about CPU usage at the moment, just want to get an image to appear on the browser !

  • I hear one issue deals with ’chunking’ - that the camera h.264 is a bitstream but h.264 streams for html5 should be chunked. Not sure how that would work.

  • I have tried VLC for some things (RTP) but haven’t have success.

  • Most resources (SE and other sites) are from 2010-2015 and it seems as thought v4l2 and other things have developed since then.

  • As my problem is most likely general ignorance of the subject matter, I would appreciate any answers that provide some general understanding as to the theory behind different techniques. I know this makes the question more of a call for opinion and less appropriate for SE, but I’m fixing to throw my computer out the window (you know the feeling).

  Thank you !

• Optimizing FFmpeg/x264 Configuration for Ultra-Low Latency UDP Streaming [closed]

  17 décembre 2024, par pourjour

  I'm implementing a real-time screen streaming application using FFmpeg's libraries (libavcodec, libavformat) with H.264 encoding and UDP transport. While I have basic low-latency settings in place, I'm looking to minimize latency as much as possible while maintaining reasonable quality.
Here's my current encoder configuration :

  


  // Configure codec for low latency
codecContext->width = WIDTH;
codecContext->height = HEIGHT;
codecContext->time_base = AVRational{1, FPS};
codecContext->framerate = AVRational{FPS, 1};
codecContext->pix_fmt = AV_PIX_FMT_YUV420P;
codecContext->gop_size = 10;
codecContext->max_b_frames = 0;
codecContext->refs = 1;
codecContext->flags |= AV_CODEC_FLAG_LOW_DELAY;
codecContext->bit_rate = 3000000;

// x264 specific settings
av_opt_set(codecContext->priv_data, "preset", "ultrafast", 0);
av_opt_set(codecContext->priv_data, "tune", "zerolatency", 0);
av_opt_set(codecContext->priv_data, "delay", "0", 0);
av_opt_set(codecContext->priv_data, "profile", "baseline", 0);
av_opt_set(codecContext->priv_data, "x264opts",
           "no-mbtree:sliced-threads:sync-lookahead=0:rc-lookahead=0:"
           "no-scenecut:no-cabac:force-cfr", 0);


  


  For network transport, I'm using MPEGTS over UDP :

  


  QString url = QString("udp://%1:%2?pkt_size=1316").arg(targetAddress).arg(targetPort);


  


  Current issues :

  


  

  • Still experiencing 200-300ms latency Some quality degradation with
fast motion Occasional frame drops

  


  


  Questions :

  


  

  • Are there additional x264 options or FFmpeg settings I should
consider for reducing latency ?

  


  • What are the optimal GOP and bitrate
settings for balancing latency vs quality ?

  


  • Are there better muxer settings or alternative container formats I should consider ?

  


  • How can I optimize the network transport settings (packet size, buffering,
etc.) ?

  


  • Are there any tradeoffs I should be aware of with my current
configuration ?

  


  


• Revision cc6117d0f3 : update nestegg + prune some unused files https://github.com/kinetiknz/nestegg.

  14 décembre 2013, par James Zern

  Changed Paths :
   Delete /nestegg/.gitignore

  
   Add /nestegg/0001-include-paths.diff

  
   Add /nestegg/0002-ne_read_simple-uninitialized_variable.diff

  
   Modify /nestegg/AUTHORS

  
   Delete /nestegg/Makefile.am

  
   Add /nestegg/README.webm

  
   Delete /nestegg/configure.ac

  
   Delete /nestegg/docs/Doxyfile.in

  
   Delete /nestegg/docs/Makefile.am

  
   Modify /nestegg/halloc/src/halloc.c

  
   Modify /nestegg/include/nestegg/nestegg.h

  
   Delete /nestegg/m4/as-ac-expand.m4

  
   Delete /nestegg/m4/ax_create_stdint_h.m4

  
   Delete /nestegg/m4/pkg.m4

  
   Delete /nestegg/nestegg-uninstalled.pc.in

  
   Delete /nestegg/nestegg.pc.in

  
   Modify /nestegg/src/nestegg.c

  
   Modify /nestegg/test/test.c

  
   Modify /test/webm_video_source.h

  
   Modify /webmdec.c

  
  
  update nestegg

  + prune some unused files

  https://github.com/kinetiknz/nestegg.git

  commit f46223191d8116a36bf299b5b9793fcb798417b1
  Merge : 0851279 4b0190a
  Author : Matthew Gregan <kinetik@flim.org>
  AuthorDate : Wed Nov 27 13:50:43 2013 -0800
  Commit : Matthew Gregan <kinetik@flim.org>
  CommitDate : Wed Nov 27 13:50:43 2013 -0800

  Merge pull request #15 from shadone/master

  Fix compiler warning.

  Change-Id : I59eecdd68fced1ef61b67d446735539628d81484