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• FFmpeg "Illegal instruction" Raspberry Pi Zero W

  20 août 2019, par ErezM

  I’ve been struggling with having FFmpeg run on Pi Zero W, as a newbie I can’t say where the root of the problem whether its the compilation configuration of the FFmpeg or maybe the syntax of the command line itself..

  The current configuration is :

  Raspberry Pi Zero Wireless
  Set GPU memory to 256

  Running OS :

  Linux raspberrypi 4.19.66+ #1253 Thu Aug 15 11:37:30 BST 2019 armv6l GNU/Linux
  
  
  
  PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
  
  NAME="Raspbian GNU/Linux"
  
  VERSION_ID="10"
  
  VERSION="10 (buster)"
  
  VERSION_CODENAME=buster
  
  ID=raspbian
  
  ID_LIKE=debian
  
  
  
  No LSB modules are available.
  
  Distributor ID: Raspbian
  
  Description: Raspbian GNU/Linux 10 (buster)
  
  Release: 10
  
  Codename: buster

  FFmpeg version and configuration :

  ffmpeg version N-94582-gd0fa1a58da Copyright (c) 2000-2019 the FFmpeg developers
  
  built with gcc 8 (Raspbian 8.3.0-6+rpi1)
  
  configuration: --arch=armel --target-os=linux --enable-gpl --enable-libx264 --enable-omx --enable-omx-rpi --enable-nonfree
  
  libavutil 56. 33.100 / 56. 33.100
  
  libavcodec 58. 55.100 / 58. 55.100
  
  libavformat 58. 31.101 / 58. 31.101
  
  libavdevice 58. 9.100 / 58. 9.100
  
  libavfilter 7. 58.100 / 7. 58.100
  
  libswscale 5. 6.100 / 5. 6.100
  
  libswresample 3. 6.100 / 3. 6.100
  
  libpostproc 55. 6.100 / 55. 6.100
  
  Hyper fast Audio and Video encoder

  Command to copy 30 seconds clip from the 10 second mark :

  sudo ffmpeg -ss 00:00:10 -t 00:00:30 -i GOPR2546.MP4 -c:v libx264 -c:a copy out.MP4

  The FFmpeg output :

  ffmpeg version N-94582-gd0fa1a58da Copyright (c) 2000-2019 the FFmpeg developers
  
  built with gcc 8 (Raspbian 8.3.0-6+rpi1)
  
  configuration: --arch=armel --target-os=linux --enable-gpl --enable-libx264 --enable-omx --enable-omx-rpi --enable-nonfree
  
  libavutil 56. 33.100 / 56. 33.100
  
  libavcodec 58. 55.100 / 58. 55.100
  
  libavformat 58. 31.101 / 58. 31.101
  
  libavdevice 58. 9.100 / 58. 9.100
  
  libavfilter 7. 58.100 / 7. 58.100
  
  libswscale 5. 6.100 / 5. 6.100
  
  libswresample 3. 6.100 / 3. 6.100
  
  libpostproc 55. 6.100 / 55. 6.100
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x210d360] Using non-standard frame rate 59/1
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'GOPR2546.MP4':
  
  Metadata:
  
  major_brand : mp41
  
  minor_version : 538120216
  
  compatible_brands: mp41
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  firmware : HD7.01.01.80.00
  
  Duration: 00:01:00.84, start: 0.000000, bitrate: 45293 kb/s
  
  Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 45043 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
  
  Metadata:
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  handler_name : GoPro AVC
  
  encoder : GoPro AVC encoder
  
  timecode : 11:20:21:32
  
  Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
  
  Metadata:
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  handler_name : GoPro AAC
  
  timecode : 11:20:21:32
  
  Stream #0:2(eng): Data: none (tmcd / 0x64636D74) (default)
  
  Metadata:
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  handler_name : GoPro TCD
  
  timecode : 11:20:21:32
  
  Stream #0:3(eng): Data: bin_data (gpmd / 0x646D7067), 41 kb/s (default)
  
  Metadata:
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  handler_name : GoPro MET
  
  Stream #0:4(eng): Data: none (fdsc / 0x63736466), 13 kb/s (default)
  
  Metadata:
  
  creation_time : 2019-08-20T11:09:41.000000Z
  
  handler_name : GoPro SOS
  
  Stream mapping:
  
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  
  Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  Illegal instruction

  The result is an empty out.MP4 file... I’ve tried different configuration but never got it to work.

  the one minute input file i’m using to test can be downloaded from https://dl.dropboxusercontent.com/s/dxd285zrz6d57da/GOPR2546.MP4

  Thank you all in advance !!

• Video Conferencing in HTML5 : WebRTC via Web Sockets

  14 juin 2012, par silvia

  A bit over a week ago I gave a presentation at Web Directions Code 2012 in Melbourne. Maxine and John asked me to speak about something related to HTML5 video, so I went for the new shiny : WebRTC – real-time communication in the browser.

  Presentation slides

  I only had 20 min, so I had to make it tight. I wanted to show off video conferencing without special plugins in Google Chrome in just a few lines of code, as is the promise of WebRTC. To a large extent, I achieved this. But I made some interesting discoveries along the way. Demos are in the slide deck.

  UPDATE : Opera 12 has been released with WebRTC support.

  Housekeeping : if you want to replicate what I have done, you need to install a Google Chrome Web Browser 19+. Then make sure you go to chrome ://flags and activate the MediaStream and PeerConnection experiment(s). Restart your browser and now you can experiment with this feature. Big warning up-front : it’s not production-ready, since there are still changes happening to the spec and there is no compatible implementation by another browser yet.

  Here is a brief summary of the steps involved to set up video conferencing in your browser :

  1. Set up a video element each for the local and the remote video stream.
  2. Grab the local camera and stream it to the first video element.
  3. (*) Establish a connection to another person running the same Web page.
  4. Send the local camera stream on that peer connection.
  5. Accept the remote camera stream into the second video element.

  Now, the most difficult part of all of this – believe it or not – is the signalling part that is required to build the peer connection (marked with (*)). Initially I wanted to run completely without a server and just enter the remote’s IP address to establish the connection. This is, however, not a functionality that the PeerConnection object provides [might this be something to add to the spec ?].

  So, you need a server known to both parties that can provide for the handshake to set up the connection. All the examples that I have seen, such as https://apprtc.appspot.com/, use a channel management server on Google’s appengine. I wanted it all working with HTML5 technology, so I decided to use a Web Socket server instead.

  I implemented my Web Socket server using node.js (code of websocket server). The video conferencing demo is in the slide deck in an iframe – you can also use the stand-alone html page. Works like a treat.

  While it is still using Google’s STUN server to get through NAT, the messaging for setting up the connection is running completely through the Web Socket server. The messages that get exchanged are plain SDP message packets with a session ID. There are OFFER, ANSWER, and OK packets exchanged for each streaming direction. You can see some of it in the below image :

  

  I’m not running a public WebSocket server, so you won’t be able to see this part of the presentation working. But the local loopback video should work.

  At the conference, it all went without a hitch (while the wireless played along). I believe you have to host the WebSocket server on the same machine as the Web page, otherwise it won’t work for security reasons.

  A whole new world of opportunities lies out there when we get the ability to set up video conferencing on every Web page – scary and exciting at the same time !

• Video Conferencing in HTML5 : WebRTC via Web Sockets

  1er janvier 2014, par silvia

  A bit over a week ago I gave a presentation at Web Directions Code 2012 in Melbourne. Maxine and John asked me to speak about something related to HTML5 video, so I went for the new shiny : WebRTC – real-time communication in the browser.

  Presentation slides

  I only had 20 min, so I had to make it tight. I wanted to show off video conferencing without special plugins in Google Chrome in just a few lines of code, as is the promise of WebRTC. To a large extent, I achieved this. But I made some interesting discoveries along the way. Demos are in the slide deck.

  UPDATE : Opera 12 has been released with WebRTC support.

  Housekeeping : if you want to replicate what I have done, you need to install a Google Chrome Web Browser 19+. Then make sure you go to chrome ://flags and activate the MediaStream and PeerConnection experiment(s). Restart your browser and now you can experiment with this feature. Big warning up-front : it’s not production-ready, since there are still changes happening to the spec and there is no compatible implementation by another browser yet.

  Here is a brief summary of the steps involved to set up video conferencing in your browser :

  1. Set up a video element each for the local and the remote video stream.
  2. Grab the local camera and stream it to the first video element.
  3. (*) Establish a connection to another person running the same Web page.
  4. Send the local camera stream on that peer connection.
  5. Accept the remote camera stream into the second video element.

  Now, the most difficult part of all of this – believe it or not – is the signalling part that is required to build the peer connection (marked with (*)). Initially I wanted to run completely without a server and just enter the remote’s IP address to establish the connection. This is, however, not a functionality that the PeerConnection object provides [might this be something to add to the spec ?].

  So, you need a server known to both parties that can provide for the handshake to set up the connection. All the examples that I have seen, such as https://apprtc.appspot.com/, use a channel management server on Google’s appengine. I wanted it all working with HTML5 technology, so I decided to use a Web Socket server instead.

  I implemented my Web Socket server using node.js (code of websocket server). The video conferencing demo is in the slide deck in an iframe – you can also use the stand-alone html page. Works like a treat.

  While it is still using Google’s STUN server to get through NAT, the messaging for setting up the connection is running completely through the Web Socket server. The messages that get exchanged are plain SDP message packets with a session ID. There are OFFER, ANSWER, and OK packets exchanged for each streaming direction. You can see some of it in the below image :

  

  I’m not running a public WebSocket server, so you won’t be able to see this part of the presentation working. But the local loopback video should work.

  At the conference, it all went without a hitch (while the wireless played along). I believe you have to host the WebSocket server on the same machine as the Web page, otherwise it won’t work for security reasons.

  A whole new world of opportunities lies out there when we get the ability to set up video conferencing on every Web page – scary and exciting at the same time !