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• avconv stops streaming after some time

  4 juin 2014, par Dhrumil Doshi

  I am using raspberry-pi board and a usb camera attached with it. i use avconv tool to capture live video from camera and streaming it on network using rtp protocol.

  My command on server(raspberry-pi board) is as below :

  avconv -f video4linux2 -s 160x120 -i /dev/video0 -vcodec mpeg2video -r 25 -pix_fmt yuv420p -me_method epzs -b 2600k -bt 256k -f rtp rtp ://192.168.1.141:8554

  streaming works successfully using this command. Here IP address 192.168.1.141 is the ip address of my client pc. i can play live streaming on client side using vlc successfully.

  But Issue is after some time encoding and streaming on server stop automatically. And command hangs there.

  Output on server is as below :

  $ avconv -f video4linux2 -s 160x120 -v debug -i /dev/video0 -vcodec mpeg2video -r 25 -pix_fmt yuv420p -me_method epzs -b 2600k -bt 256k -f rtp rtp://192.168.1.141:8554
  
  avconv version 0.8.10-6:0.8.10-1+rpi1, Copyright (c) 2000-2013 the Libav developers
  
    built on Mar 22 2014 02:13:15 with gcc 4.6.3
  
    configuration: --arch=arm --enable-pthreads --enable-runtime-cpudetect --extra-version='6:0.8.10-1+rpi1' --libdir=/usr/lib/arm-linux-gnueabihf --prefix=/usr --disable-yasm --enable-bzlib --enable-libdc1394 --enable-libdirac --enable-libfreetype --enable-frei0r --enable-gnutls --enable-libgsm --enable-libmp3lame --enable-librtmp --enable-libopencv --enable-libopenjpeg --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-vaapi --enable-vdpau --enable-libvorbis --enable-libvpx --enable-zlib --enable-gpl --enable-postproc --enable-swscale --enable-libcdio --enable-x11grab --enable-libx264 --enable-libxvid --shlibdir=/usr/lib/arm-linux-gnueabihf --enable-shared --disable-static
  
    libavutil    51. 22. 2 / 51. 22. 2
  
    libavcodec   53. 35. 0 / 53. 35. 0
  
    libavformat  53. 21. 1 / 53. 21. 1
  
    libavdevice  53.  2. 0 / 53.  2. 0
  
    libavfilter   2. 15. 0 /  2. 15. 0
  
    libswscale    2.  1. 0 /  2.  1. 0
  
    libpostproc  52.  0. 0 / 52.  0. 0
  
  [video4linux2 @ 0x54d7a0] [4]Capabilities: 84000001
  
  [video4linux2 @ 0x54d7a0] The V4L2 driver changed the pixel format from 0x32315559 to 0x56595559
  
      Last message repeated 1 times
  
  [video4linux2 @ 0x54d7a0] The V4L2 driver changed the pixel format from 0x50323234 to 0x56595559
  
  [video4linux2 @ 0x54d7a0] The V4L2 driver set input_id: 0, input: Camera 1
  
  [rawvideo @ 0x54f860] err{or,}_recognition separate: 1; 1
  
  [rawvideo @ 0x54f860] err{or,}_recognition combined: 1; 1
  
  [video4linux2 @ 0x54d7a0] All info found
  
  [video4linux2 @ 0x54d7a0] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, video4linux2, from '/dev/video0':
  
    Duration: N/A, start: 21891.364784, bitrate: 9216 kb/s
  
      Stream #0.0, 1, 1/1000000: Video: rawvideo, yuyv422, 160x120, 1/30, 9216 kb/s, 30 tbr, 1000k tbn, 30 tbc
  
  [buffer @ 0x54f220] w:160 h:120 pixfmt:yuyv422
  
  [avsink @ 0x54d740] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
  
  [scale @ 0x54f7e0] w:160 h:120 fmt:yuyv422 -> w:160 h:120 fmt:yuv420p flags:0x4
  
  [mpeg2video @ 0x54ea60] err{or,}_recognition separate: 1; 1
  
  [mpeg2video @ 0x54ea60] err{or,}_recognition combined: 1; 1
  
  [mpeg2video @ 0x54ea60] detected 1 logical cores
  
  [mpeg2video @ 0x54ea60] Unsupported bit depth: 0
  
  [rawvideo @ 0x54f860] err{or,}_recognition separate: 1; 1
  
  [rawvideo @ 0x54f860] err{or,}_recognition combined: 1; 1
  
  Output #0, rtp, to 'rtp://192.168.1.141:8554':
  
    Metadata:
  
      encoder         : Lavf53.21.1
  
      Stream #0.0, 0, 1/90000: Video: mpeg2video, yuv420p, 160x120, 1/25, q=2-31, 2600 kb/s, 90k tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo -> mpeg2video)
  
  SDP:
  
  v=0
  
  o=- 0 0 IN IP4 127.0.0.1
  
  s=No Name
  
  c=IN IP4 192.168.1.141
  
  t=0 0
  
  a=tool:libavformat 53.21.1
  
  m=video 8554 RTP/AVP 32
  
  b=AS:2600
  
  
  
  Press ctrl-c to stop encoding
  
  *** drop!
  
      Last message repeated 1 times
  
  *** 1 dup!
  
  *** 16 dup! fps= 25 q=2.0 size=    1027kB time=5.24 bitrate=1605.2kbits/s dup=1 drop=2    
  
  *** drop!
  
      Last message repeated 11 times
  
  *** drop!49 fps= 26 q=2.0 size=    1059kB time=5.92 bitrate=1464.9kbits/s dup=17 drop=14    
  
      Last message repeated 2 times
  
  *** drop!76 fps= 25 q=2.0 size=    2022kB time=11.00 bitrate=1505.7kbits/s dup=17 drop=17    
  
  *** drop!48 fps= 25 q=2.0 size=    4086kB time=21.88 bitrate=1529.8kbits/s dup=17 drop=18    
  
  *** 1 dup!
  
  *** 1 dup!0 fps= 25 q=2.0 size=    4171kB time=22.36 bitrate=1528.2kbits/s dup=18 drop=19    
  
  *** 1 dup!1 fps= 25 q=2.0 size=    4859kB time=26.00 bitrate=1530.8kbits/s dup=19 drop=19    
  
  *** 1 dup!0 fps= 25 q=2.0 size=    5152kB time=27.56 bitrate=1531.5kbits/s dup=20 drop=19    
  
  *** 1 dup!3 fps= 25 q=2.0 size=    5250kB time=28.08 bitrate=1531.7kbits/s dup=21 drop=19    
  
  *** drop!64 fps= 25 q=2.0 size=    7215kB time=38.52 bitrate=1534.5kbits/s dup=22 drop=19    
  
  *** 1 dup!6 fps= 25 q=2.0 size=    7306kB time=39.00 bitrate=1534.6kbits/s dup=22 drop=20    
  
  *** drop!07 fps= 25 q=2.0 size=    8288kB time=44.24 bitrate=1534.7kbits/s dup=23 drop=20    
  
  *** 1 dup!0 fps= 25 q=2.0 size=   10054kB time=53.56 bitrate=1537.8kbits/s dup=23 drop=21    
  
  *** 1 dup!9 fps= 25 q=2.0 size=   10342kB time=55.12 bitrate=1537.1kbits/s dup=24 drop=21    
  
      Last message repeated 1 times
  
  *** drop!93 fps= 25 q=1.6 size=   10445kB time=55.68 bitrate=1536.7kbits/s dup=26 drop=21    
  
  *** 1 dup!
  
  *** 7036829 dup! 25 q=2.0 size=   10630kB time=56.68 bitrate=1536.4kbits/s dup=27 drop=22 

  Any ideas ?

  Thanks in advance.

• VP8 for Real-time Video Applications

  15 février 2011, par noreply@blogger.com (John Luther)

  With the growing interest in videoconferencing on the web platform, it’s a good time to explore the features of VP8 that make it an exceptionally good codec for real-time applications like videoconferencing.

  VP8 Design History & Features

  Real-time applications were a primary use case when VP8 was designed. The VP8 encoder has features specifically engineered to overcome the challenges inherent in compressing and transmitting real-time video data.
  

  • Processor-adaptive encoding. 16 encoder complexity levels automatically (or manually) adjust encoder features such as motion search strategy, quantizer optimizations, and loop filtering strength.
  • Encoder can be configured to use a target percentage of the host CPU.
    Ability to measure the time taken to encode each frame and adjust encoder complexity dynamically to keep the encoding time per frame constant
  • Robust error recovery (packet retransmission, forward error correction, recovery frame/new keyframe requests)
  • Temporal scalability (i.e., a single video bitstream that can degrade as needed depending on a participant’s available bandwidth)
  • Highly efficient decoding performance on low-power devices. Conventional video technology has grown to a state of complexity where dedicated hardware chips are needed to make it work well. With VP8, software-based solutions have proven to meet customer needs without requiring specialized hardware.

  For a more information about real-time video features in VP8, see the slide presentation by WebM Project engineer Paul Wilkins (PDF file).

  Commercially Available Products

  Millions of people around the world have been using VP7/8 for video chat for years. VP8 is deployed in some of today’s most popular consumer videoconferencing applications, including Skype (group video calling), Sightspeed, ooVoo and Logitech Vid. All of these vendors are active WebM project supporters. VP8’s predecessor, VP7, has been used in Skype video calling since 2005 and is supported in the new Skype app for iPhone. Other real-time VP8 implementations are coming soon, including ooVoo, and VP8 will play a leading role in Google’s plans for real-time applications on the web platform.

  Real-time applications will be extremely important as the web platform matures. The WebM community has made significant improvements in VP8 for real-time use cases since our launch and will continue to do so in the future.

  John Luther is Product Manager of the WebM Project.

  

• Modify MBAFF chroma deblock functions to handle U/V at the same time

  30 novembre 2011, par Jason Garrett-Glaser

  Modify MBAFF chroma deblock functions to handle U/V at the same time