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• images->video->web canvas : RGB/YUV issues

  5 février 2016, par nrob

  We’ve written an web app which :

  1. takes 3D, time dependent weather data
  2. tiles each 3D time point to make a 2D frame (written out as a png image)
  3. stitches these frames together into a video (using ffmpeg/avconv)
  4. streams this video into a web app
  5. polls the canvas for frames
  6. sends the frames to the GPU where they are converted back to 3D and ray traced

  You can see the app here, code here and you can see the data video here

  Currently the pngs are written as RGB images, the video codec is in YUV and getting frames from the canvas returns RGB. As such there is a significant loss of information due to the conversion between image spaces.

  Does anyone have suggestions what is the best way round this ?

  I’ve tried a bunch of RGB video codecs, but I can’t get any to work, and I don’t know if the web browser will support it anyway. Can anyone suggest a good RGB codec (both lossy and lossless would be great)

  Also, is it possible to write to YUV images/read them from a video canvas in HTML5 ?

  Ultimately, I don’t even want anything to do with images/videos, I’m just hacking the codecs to stream/compress large animated 3D data volumes

• Stream to Azure Media Service from ffmpeg, stream can not be played

  24 juillet 2015, par Simon

  i try to send a stream from my RaspberryPI with debian wheezy to the AzureMediaService.
  I followed the instructions of this nice post.
  http://gtrifonov.com/2015/07/02/streaming-live-video-from-raspberrypi-to-azure-media-services/

  After a lot of trouble with the ffmpeg and libx264 builds i think i have it working now, to stream to the rtmp urls.

  INGESTURI="rtmp://office-klokklokmediastream.channel.mediaservices.windows.net:1935/live/3e541bc149754ebd975b95ec3583c949/mystream1"
  
  ffmpeg -framerate 30 -r 30 -s 640x480 -i /dev/video0 -vcodec libx264 -preset ultrafast -acodec libfaac -ab 48k -b:v 500k -maxrate 500k -bufsize 500k -r 30 -g 60 -keyint_min 60 -sc_threshold 0 -f flv $INGESTURI

  But when i try to watch the link in azure portal publish link or with the azure amsmediaplayer it tells me (i have reseted the channel already) :

  "The video could not be loaded, either because the server or network failed or because the format is not supported."

  The public stream url is :

  http://klokklokmediastream.streaming.mediaservices.windows.net/30c3920e-420a-4d33-8938-e79d0db240ff/c9fd3479-0d4b-4643-a3f9-5fd5831985d0.ism/Manifest

  In the linux shell i see the following output while streaming, looks for me as send stream is working :

  "root@raspberrypi:/home/pi/klokklok# ./azure_ffmpeg
  
  ffmpeg version N-73894-g830d3a0 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.6 (Debian 4.6.3-14+rpi1)
  
    configuration: --arch=armel --target-os=linux --enable-gpl --enable-libx264 --enable-nonfree
  
    libavutil      54. 28.100 / 54. 28.100
  
    libavcodec     56. 50.101 / 56. 50.101
  
    libavformat    56. 40.101 / 56. 40.101
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 25.100 /  5. 25.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.101 /  1.  2.101
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, video4linux2,v4l2, from '/dev/video0':
  
    Duration: N/A, start: -140462028.282167, bitrate: 110592 kb/s
  
      Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 640x480, 110592 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
  
  [libx264 @ 0x3321920] using cpu capabilities: none!
  
  [libx264 @ 0x3321920] profile Constrained Baseline, level 3.0
  
  [libx264 @ 0x3321920] 264 - core 146 r2538 121396c - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=1 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=60 keyint_min=31 scenecut=0 intra_refresh=0 rc_lookahead=0 rc=cbr mbtree=0 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=500 vbv_bufsize=500 nal_hrd=none filler=0 ip_ratio=1.40 aq=0
  
  Output #0, flv, to 'rtmp://office-klokklokmediastream.channel.mediaservices.windows.net:1935/live/3e501bc149754ebd975b95ec3583c949/mystream1':
  
    Metadata:
  
      encoder         : Lavf56.40.101
  
      Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv420p, 640x480, q=-1--1, 500 kb/s, 30 fps, 1k tbn, 30 tbc
  
      Metadata:
  
        encoder         : Lavc56.50.101 libx264
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  
  Press [q] to stop, [?] for help
  
  DTS 140462610481701, next:33333 st:0 invalid dropping
  
  PTS 140462610481701, next:33333 invalid dropping st:0
  
  DTS 140462610515017, next:66666 st:0 invalid dropping
  
  PTS 140462610515017, next:66666 invalid dropping st:0
  
  DTS 140462610548333, next:99999 st:0 invalid dropping
  
  PTS 140462610548333, next:99999 invalid dropping st:0
  
  frame=    4 fps=0.0 q=31.0 size=       7kB time=00:00:00.10 bitrate= 554.6kbits/DTS 140462610581650, next:133332 st:0 invalid dropping
  
  PTS 140462610581650, next:133332 invalid dropping st:0
  
  DTS 140462610614965, next:166665 st:0 invalid dropping
  
  PTS 140462610614965, next:166665 invalid dropping st:0
  
  frame=    6 fps=5.1 q=29.0 size=       9kB time=00:00:00.16 bitrate= 462.5kbits/DTS 140462610648281, next:199998 st:0 invalid dropping
  
  PTS 140462610648281, next:199998 invalid dropping st:0
  
  DTS 140462610681598, next:233331 st:0 invalid dropping
  
  PTS 140462610681598, next:233331 invalid dropping st:0
  
  DTS 140462610714914, next:266664 st:0 invalid dropping
  
  PTS 140462610714914, next:266664 invalid dropping st:0
  
  frame=   14 fps=4.6 q=23.0 size=      21kB time=00:00:00.43 bitrate= 396.0kbits/DTS 140462610914810, next:466662 st:0 invalid dropping
  
  PTS 140462610914810, next:466662 invalid dropping st:0
  
  [flv @ 0x3320ae0] Failed to update header with correct duration.
  
  [flv @ 0x3320ae0] Failed to update header with correct filesize.
  
  frame=   15 fps=3.9 q=22.0 Lsize=      25kB time=00:00:00.50 bitrate= 407.8kbits/s
  
  video:24kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.373589%
  
  [libx264 @ 0x3321920] frame I:1     Avg QP:31.00  size:  2777
  
  [libx264 @ 0x3321920] frame P:14    Avg QP:26.68  size:  1531
  
  [libx264 @ 0x3321920] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x3321920] mb P  I16..4: 12.4%  0.0%  0.0%  P16..4: 29.7%  0.0%  0.0%  0.0%  0.0%    skip:57.9%
  
  [libx264 @ 0x3321920] coded y,uvDC,uvAC intra: 6.3% 13.9% 0.5% inter: 5.7% 21.4% 0.1%
  
  [libx264 @ 0x3321920] i16 v,h,dc,p: 52% 17% 16% 14%
  
  [libx264 @ 0x3321920] i8c dc,h,v,p: 63% 14% 20%  3%
  
  [libx264 @ 0x3321920] kb/s:387.47
  
  Exiting normally, received signal 2.
  
  "

  I cant find a solution for that so thanks a lot for any advice.

• Senior Software Engineer for Enterprise Analytics Platform

  28 janvier 2016, par Matthieu Aubry — Uncategorized

  We’re looking for a lead developer to work on Piwik Enterprise Analytics core platform software. We have some exciting challenges to solve and need you !

  You’ll be working with both fellow employees and our open-source community. Piwik staff lives in New Zealand, Europe (Poland, Germany) and in the U.S. We do the vast majority of our collaboration online.

  We are a small, flexible team, so when you come aboard, you will play an integral part in engineering. As a leader you’ll help us to prioritise work and grow our community. You’ll help to create a welcoming environment for new contributors and set an example with your development practices and communications skills. You will be working closely with our CTO to build a future for Piwik.

  Key Responsibilities

  • Strong competency coding in PHP and JavaScript.
  • Scaling existing backend system to handle ever increasing amounts of traffic and new product requirements.
  • Outstanding communication and collaboration skills.
  • Drive development and documentation of internal and external APIs (Piwik is an open platform).
  • Help make our development practices better and reduce friction from idea to deployment.
  • Mentor junior engineers and set the stage for personal growth.

  Minimum qualifications

  • 5+ years of experience in product development, security, usable interface design.
  • 5+ years experience building successful production software systems.
  • Strong competency in PHP5 and JavaScript application development.
  • Skill at writing tests and reviewing code.
  • Strong analytical skills.

  Location

  • Remote work position !
  • or you can join us in our office based in Wellington, New Zealand or in Wrocław, Poland.

  Benefits

  • Competitive salary.
  • Remote work is possible.
  • Yearly meetup with the whole team abroad.
  • Be part of a successful open source company and community.
  • In our Wellington (NZ) and Wroclaw (PL) offices : snacks, coffee, nap room, Table football, Ping pong…
  • Regular events.
  • Great team of people.
  • Exciting projects.

  Learn more

  Learn more what it’s like to work on Piwik in our blog post

  About Piwik

  At Piwik we develop the leading open source web analytics platform, used by more than one million websites worldwide. Our vision is to help the world liberate their analytics data by building the best open alternative to Google Analytics.

  The Piwik platform collects, stores and processes a lot of information : hundreds of millions of data points each month. We create intuitive, simple and beautiful reports that delight our users.

  Apply online

  To apply for this position, please Apply online here. We look forward to receiving your applications !