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• How to parallelize this for loop for rapidly converting YUV422 to RGB888 ?

  16 avril 2015, par vineet

  I am using v4l2 api to grab images from a Microsoft Lifecam and then transferring these images over TCP to a remote computer. I am also encoding the video frames into a MPEG2VIDEO using ffmpeg API. These recorded videos play too fast which is probably because not enough frames have been captured and due to incorrect FPS settings.

  The following is the code which converts a YUV422 source to a RGB888 image. This code fragment is the bottleneck in my code as it takes nearly 100 - 150 ms to execute which means I can’t log more than 6 - 10 FPS at 1280 x 720 resolution. The CPU usage is 100% as well.

  for (int line = 0; line < image_height; line++) {
  
      for (int column = 0; column < image_width; column++) {
  
          *dst++ = CLAMP((double)*py + 1.402*((double)*pv - 128.0));                                                  // R - first byte           
  
          *dst++ = CLAMP((double)*py - 0.344*((double)*pu - 128.0) - 0.714*((double)*pv - 128.0));    // G - next byte
  
          *dst++ = CLAMP((double)*py + 1.772*((double)*pu - 128.0));                                                            // B - next byte
  
  
  
          vid_frame->data[0][line * frame->linesize[0] + column] = *py; 
  
  
  
          // increment py, pu, pv here
  
  
  
      }

  ’dst’ is then compressed as jpeg and sent over TCP and ’vid_frame’ is saved to the disk.

  How can I make this code fragment faster so that I can get atleast 30 FPS at 1280x720 resolution as compared to the present 5-6 FPS ?

  I’ve tried parallelizing the for loop across three threads using p_thread, processing one third of the rows in each thread.

  for (int line = 0; line < image_height/3; line++) // thread 1
  
  for (int line = image_height/3; line < 2*image_height/3; line++) // thread 2
  
  for (int line = 2*image_height/3; line < image_height; line++) // thread 3

  This gave me only a minor improvement of 20-30 milliseconds per frame.
  What would be the best way to parallelize such loops ? Can I use GPU computing or something like OpenMP ? Say spwaning some 100 threads to do the calculations ?

  I also noticed higher frame rates with my laptop webcam as compared to the Microsoft USB Lifecam.

  Here are other details :

  • Ubuntu 12.04, ffmpeg 2.6
  • AMG-A8 quad core processor with 6GB RAM
  • Encoder settings :
    • codec : AV_CODEC_ID_MPEG2VIDEO
    • bitrate : 4000000
    • time_base : (AVRational)1, 20
    • pix_fmt : AV_PIX_FMT_YUV420P
    • gop : 10
    • max_b_frames : 1

• ffmpeg rtmp live stream to Azure Media Services

  18 mars 2015, par Pilskalns

  Somehow I got publishing Azure Media Services to work, except there is huge frame drop (almost every frame) with those settings :

  ffmpeg -i "http://stream01/hls/live/playlist-mid.m3u8" -strict -2 -c:a aac -b:a 192k
  
  -ar 44100 -r 25 -g 60 -keyint_min 60 -b:v 2000k -c:v libx264 -bufsize 2000k
  
  -maxrate 2000k -f flv "rtmp://publishurl.working.is/mystream1"

  + I can’t play URL from Azure.

  When I publish to local nginx-rtmp server, frame drop stays and despite it I can play it. So, I believe that frame drop is ffmpeg related not Azure. Processor is not overloaded, available bandwidth is excellent.

  When I try original settings from this URL (at very bottom), I this get additionaly this ffmpeg error Past duration 0.719994 too large

  Here’s more from output :

  c:\ffmpeg\bin>ffmpeg -i "http://stream01/hls/live/playlist-mid.m3u8" -strict -2 -c:a aac -b:a 192k -ar 44100 -r 25 -g 60 -keyint_min 60 -b:v 2000k -c:
  
  v libx264 -bufsize 1000k -maxrate 2000k -f flv "rtmp://********.channel.mediaservices.windows.net:1935/live/9590f0be/mystream1"
  
  ffmpeg version N-69972-g6c91afe Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.9.2 (GCC)
  
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnu
  
  tls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-
  
  libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-l
  
  ibrtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --
  
  enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --ena
  
  ble-libxvid --enable-lzma --enable-decklink --enable-zlib
  
    libavutil      54. 19.100 / 54. 19.100
  
    libavcodec     56. 25.100 / 56. 25.100
  
    libavformat    56. 23.100 / 56. 23.100
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 11.100 /  5. 11.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  Input #0, hls,applehttp, from 'http://stream01/hls/live/playlist-mid.m3u8':
  
    Duration: N/A, start: 3314.605633, bitrate: N/A
  
    Program 0
  
      Metadata:
  
        variant_bitrate : 1500000
  
      Stream #0:0: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv), 854x480 [SAR 1:1 DAR 427:240], 50 fps, 50 tbr, 90k tbn, 100 tbc
  
      Metadata:
  
        variant_bitrate : 1500000
  
      Stream #0:1: Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 216 kb/s
  
      Metadata:
  
        variant_bitrate : 1500000
  
  [libx264 @ 0000000000306280] using SAR=1/1
  
  [libx264 @ 0000000000306280] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
  
  [libx264 @ 0000000000306280] profile High, level 3.0
  
  [libx264 @ 0000000000306280] 264 - core 144 r2525 40bb568 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options:
  
   cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 dead
  
  zone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_in
  
  tra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=60 keyint_min=31 scenecut=40 intra_refresh=0 rc_lookahea
  
  d=40 rc=cbr mbtree=1 bitrate=2000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 vbv_maxrate=2000 vbv_bufsize=1000 nal_hrd=none filler=0 ip_ratio=1.
  
  40 aq=1:1.00
  
  Output #0, flv, to 'rtmp://*******.channel.mediaservices.windows.net:1935/live/37b4e25/mystream1':
  
    Metadata:
  
      encoder         : Lavf56.23.100
  
      Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv420p, 854x480 [SAR 1:1 DAR 427:240], q=-1--1, 2000 kb/s, 25 fps, 1k tbn, 25 tbc
  
      Metadata:
  
        variant_bitrate : 1500000
  
        encoder         : Lavc56.25.100 libx264
  
      Stream #0:1: Audio: aac ([10][0][0][0] / 0x000A), 44100 Hz, stereo, fltp, 192 kb/s
  
      Metadata:
  
        variant_bitrate : 1500000
  
        encoder         : Lavc56.25.100 aac
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  
    Stream #0:1 -> #0:1 (aac (native) -> aac (native))
  
  Press [q] to stop, [?] for help
  
  [flv @ 0000000000305820] Failed to update header with correct duration.1.4kbits/s dup=0 drop=10697
  
  [flv @ 0000000000305820] Failed to update header with correct filesize.
  
  frame=10714 fps= 24 q=-1.0 Lsize=  100583kB time=00:07:11.08 bitrate=1911.4kbits/s dup=0 drop=10701
  
  video:90024kB audio:10042kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.516478%
  
  [libx264 @ 0000000000306280] frame I:190   Avg QP:10.58  size: 72438
  
  [libx264 @ 0000000000306280] frame P:3406  Avg QP:14.32  size: 19296
  
  [libx264 @ 0000000000306280] frame B:7118  Avg QP:19.55  size:  1784
  
  [libx264 @ 0000000000306280] consecutive B-frames:  8.8%  4.4% 10.5% 76.3%
  
  [libx264 @ 0000000000306280] mb I  I16..4: 23.0% 20.2% 56.8%
  
  [libx264 @ 0000000000306280] mb P  I16..4:  2.7%  4.5%  5.2%  P16..4: 41.9% 11.6%  8.7%  0.0%  0.0%    skip:25.4%
  
  [libx264 @ 0000000000306280] mb B  I16..4:  0.1%  0.1%  0.2%  B16..8: 26.5%  2.2%  0.5%  direct: 3.2%  skip:67.1%  L0:51.0% L1:38.2% BI:10.8%
  
  [libx264 @ 0000000000306280] 8x8 transform intra:31.3% inter:36.6%
  
  [libx264 @ 0000000000306280] coded y,uvDC,uvAC intra: 80.5% 73.5% 51.1% inter: 16.1% 18.8% 5.8%
  
  [libx264 @ 0000000000306280] i16 v,h,dc,p: 21% 29% 27% 23%
  
  [libx264 @ 0000000000306280] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 22% 32% 19%  4%  4%  4%  5%  4%  7%
  
  [libx264 @ 0000000000306280] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 30% 15%  4%  5%  5%  5%  4%  5%
  
  [libx264 @ 0000000000306280] i8c dc,h,v,p: 38% 30% 24%  8%
  
  [libx264 @ 0000000000306280] Weighted P-Frames: Y:1.8% UV:0.4%
  
  [libx264 @ 0000000000306280] ref P L0: 78.0%  8.5% 10.1%  3.3%  0.0%
  
  [libx264 @ 0000000000306280] ref B L0: 91.3%  7.9%  0.8%
  
  [libx264 @ 0000000000306280] ref B L1: 95.4%  4.6%
  
  [libx264 @ 0000000000306280] kb/s:1716.97
  
  Received signal 2: terminating.

• Can't obtain information with ffmpeg from Smooth Streaming Manifest file

  5 mars 2015, par Alberto

  I’m trying to get details for a stream of protocol Microsoft Smooth Streaming, with ffmpeg tools (ffprobe and ffplay) but when I run the next command :

  ffprobe -i http://b31282.cdn.telefonica.com/31282/Manifest

  I obtain this :

  http://b31282.cdn.telefonica.com/31282/Manifest: Invalid data found when processing input

  I assume that this Manifest file is correct and complies with standards of Smooth Streaming . This is a brief extract of Manifest file :

  <smoothstreamingmedia majorversion="2" minorversion="0" duration="0" timescale="10000000" islive="TRUE" lookaheadfragmentcount="2" dvrwindowlength="6000000000" canseek="TRUE" canpause="TRUE">
  
    <protection>
  
      <protectionheader systemid="9a04f079-9840-4286-ab92-e65be0885f95">oioAAAIAAQCUAjwAV...</protectionheader>
  
    </protection>
  
    <streamindex type="audio" language="esp" subtype="" chunks="0" timescale="10000000" url="QualityLevels({bitrate})/Fragments(audio_esp={start time})"></streamindex>
  
    <streamindex type="video" language="" subtype="" chunks="0" timescale="10000000" url="QualityLevels({bitrate})/Fragments(video={start time})"></streamindex>
  
  </smoothstreamingmedia>

  Is a Fedora 21 and ffmpeg version and configuration is :

  ffmpeg version git-2015-02-27-d490b26
  
  configuration: --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264
  
  libavutil         54. 19.100         
  
  libavcodec        56. 26.100          
  
  libavformat       56. 23.105           
  
  libavdevice       56.  4.100                   
  
  libavfilter        5. 11.102          
  
  libswscale         3.  1.101        
  
  libswresample      1.  1.100           
  
  libpostproc       53.  3.100 

  PD : I prefer use only ffmpeg tool

  PD2 : Same thing with a Microsoft Smooth Streaming Manifest file :

  ffmpeg -i http://mediadl.microsoft.com/mediadl/iisnet/smoothmedia/Experience/BigBuckBunny_720p.ism/Manifest
  
  Invalid data found when processing input

  Thanks for all