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• avdevice/decklink : remove pthread dependency

  15 avril 2017, par Aaron Levinson

  avdevice/decklink : remove pthread dependency
  Purpose : avdevice/decklink : Removed pthread dependency by replacing
  
  semaphore used in code appropriately.  Doing so makes it easier to
  
  build ffmpeg using Visual C++ on Windows.  This is a contination of
  
  Kyle Schwarz's "avdevice/decklink : Remove pthread dependency" patch
  
  that is available at https://patchwork.ffmpeg.org/patch/2654/ .  This
  
  patch wasn't accepted, and as far as I can tell, there was no
  
  follow-up after it was rejected.
  Notes : Used Visual Studio 2015 (with update 3) for this.
  Comments :
  — configure : Eliminated pthreads dependency for decklink_indev_deps
  
     and decklink_outdev_deps and replaced with threads dependency
  — libavdevice/decklink_common.cpp / .h :
  
  a) Eliminated semaphore and replaced with a combination of a mutex,
  
     condition variable, and a counter (frames_buffer_available_spots).
  
  b) Removed include of pthread.h and semaphore.h and now using
  
     libavutil/thread.h instead.
  — libavdevice/decklink_dec.cpp : Eliminated include of pthread.h and
  
     semaphore.h.
  — libavdevice/decklink_enc.cpp :
  
  a) Eliminated include of pthread.h and semaphore.h.
  
  b) Replaced use of semaphore with the equivalent using a combination
  
     of a mutex, condition variable, and a counter
  
     (frames_buffer_available_spots).  In theory, libavutil/thread.h and
  
     the associated code could have been modified instead to add
  
     cross-platform implementations of the sem_ functions, but an
  
     inspection of the ffmpeg source base indicates that there are only
  
     two cases in which semaphores are used (including this one that was
  
     replaced), so it was deemed to not be worth the effort.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] configure
  • [DH] libavdevice/decklink_common.cpp
  • [DH] libavdevice/decklink_common.h
  • [DH] libavdevice/decklink_dec.cpp
  • [DH] libavdevice/decklink_enc.cpp

• FFMPEG audio/video livestream with html5 dashjs player : time is not sync

  14 avril 2017, par Dániel Kis

  I am going to create a live video & audio stream with ffmeg with libvpx-vp9 codec, and I want to view it from html5 browser with dashjs. But when the dashjs opens the video it seatches for chunks than not yet exits. It seems that the chunk counter is running in double speed in client side.

  Here is how I create the stream :

  VP9_LIVE_PARAMS="-speed 6 -tile-columns 4 -frame-parallel 1 -threads 8 -static-thresh 0 -max-intra-rate 300 -deadline realtime -lag-in-frames 0 -error-resilient 1"
  
  TARGET_PATH="/var/www/html/live/stream"
  
  
  
  ffmpeg \
  
    -thread_queue_size 8192 \
  
    -f v4l2 -input_format mjpeg -r 30 -s 640x360 -i /dev/video0 \
  
    -thread_queue_size 16384 \
  
    -f alsa -ar 44100 -ac 2 -i hw:1,0 \
  
    -map 0:0 \
  
    -pix_fmt yuv422p \
  
    -c:v libvpx-vp9 \
  
      -s 640x360 -keyint_min 60 -g 60 ${VP9_LIVE_PARAMS} \
  
      -b:v 300k \
  
    -f webm_chunk \
  
      -header "${TARGET_PATH}/glass_360.hdr" \
  
      -chunk_start_index 1 \
  
    "${TARGET_PATH}/glass_360_%d.chk" \
  
    -map 1:0 \
  
    -c:a libvorbis \
  
      -b:a 64k -ar 44100 \
  
    -f webm_chunk \
  
      -audio_chunk_duration 2000 \
  
      -header "${TARGET_PATH}/glass_171.hdr" \
  
      -chunk_start_index 1 \
  
    "${TARGET_PATH}/glass_171_%d.chk" \

  some seconds later I call the ffmpeg again to create manifest file :

  ffmpeg \
  
    -analyzeduration 1000\
  
    -f webm_dash_manifest -live 1 \
  
    -i "${TARGET_PATH}/glass_360.hdr" \
  
    -f webm_dash_manifest -live 1 \
  
    -i "${TARGET_PATH}/glass_171.hdr" \
  
    -c copy \
  
    -map 0 -map 1 \
  
    -f webm_dash_manifest -live 1 \
  
      -adaptation_sets "id=0,streams=0 id=1,streams=1" \
  
      -chunk_start_index 1 \
  
      -chunk_duration_ms 2000 \
  
      -time_shift_buffer_depth 7200 \
  
      -minimum_update_period 7200 \
  
    "${TARGET_PATH}/glass_live_manifest.mpd"

  My server’s clock is synced to "http://time.akamai.com/?iso"

  HTML5 player :

   
  
      
  
      
  
      
  
      
  
      
  
      <code class="echappe-js">&lt;script src=&quot;https://cdn.dashjs.org/latest/dash.all.min.js&quot;&gt;&lt;/script&gt;
  
  
    
  Live broadcast
    
  
     
  
         
     
     
  &lt;script&gt;<br />
  
                  var url = &quot;glass_live_manifest.mpd&quot;;<br />
  
                  var player = dashjs.MediaPlayer().create();<br />
  
                  player.initialize(document.querySelector(&quot;#videoPlayer&quot;), url, true);<br />
  
  <br />
  
     &lt;/script&gt;
     
    
   
  

• Displaying the current frame of a video after skipping using drawtext/start_number not evaluation any variables

  30 mars 2017, par DJ Quardaboff

  I would like to display the current frame number on a video while playing it with ffplay. I have already seen this solution, but when I seek to any part of the video, the counter resets. There’s a variable, start_number, which the ffplay documentation says is The starting frame number for the n/frame_num variable. The default value is "0". It seems that n is set to that when starting the video or seeking between I-frames. I thought setting this variable to %{floor(t*60)} would solve my problem, but after running this :

  ffplay -i "video.mp4" -vf drawtext="fontsize=30:box=1:boxcolor=white:fontcolor=black:fontfile=/Windows/Fonts/arial.ttf:start_number=floor(t*60):text=%{n}"

  I got the following console output :

  ffplay version N-84679-gd65b595 Copyright (c) 2003-2017 the FFmpeg developers
  
    built with gcc 6.3.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --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-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  
    libavutil      55. 51.100 / 55. 51.100
  
    libavcodec     57. 86.103 / 57. 86.103
  
    libavformat    57. 67.100 / 57. 67.100
  
    libavdevice    57.  3.101 / 57.  3.101
  
    libavfilter     6. 78.100 /  6. 78.100
  
    libswscale      4.  3.101 /  4.  3.101
  
    libswresample   2.  4.100 /  2.  4.100
  
    libpostproc    54.  2.100 / 54.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4':=    0B f=0/0
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      creation_time   : 2017-03-30T02:49:20.000000Z
  
      encoder         : Open Broadcaster Software v0.659b
  
    Duration: 00:05:36.85, start: 0.000000, bitrate: 72636 kb/s
  
      Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 162 kb/s (default)
  
      Metadata:
  
    creation_time   : 2017-03-30T02:49:20.000000Z
  
    handler_name    : Sound Media Handler
  
  Stream #0:1(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-1), 2560x1440, 72465 kb/s, 60 fps, 60 tbr, 1k tbn, 120 tbc (default)
  
  Metadata:
  
    creation_time   : 2017-03-30T02:49:20.000000Z
  
    handler_name    : Video Media Handler
  
    encoder         : AVC Coding
  
  [drawtext @ 00000000122770e0] [Eval @ 0000000008f3eb60] Undefined constant or missing '(' in 't*60)'
  
  [drawtext @ 00000000122770e0] Unable to parse option value "floor(t*60)"
  
  [drawtext @ 00000000122770e0] [Eval @ 0000000008f3ebd0] Undefined constant or missing '(' in 't*60)'
  
  [drawtext @ 00000000122770e0] Unable to parse option value "floor(t*60)"
  
  [drawtext @ 00000000122770e0] Error setting option start_number to value floor(t*60).
  
  [Parsed_drawtext_0 @ 000000000263eca0] Error applying options to the filter.
  
  Error initializing filter 'drawtext' with args 'fontsize=30:box=1:boxcolor=white:fontcolor=black:fontfile=/Windows/Fonts/arial.ttf:start_number=floor(t*60):text=%{n}'
  
     0.01 A-V:    nan fd=   0 aq=   22KB vq= 5866KB sq=    0B f=0/0

  In fact, any variable in start_number’s assignment invokes this error. I don’t know if I have the correct syntax, but does this mean it doesn’t evaluate expressions ? Or maybe it doesn’t accept variables for some reason ?

  After that downer I tried just setting the text to %{t}, which played the video, but repeatedly gave this error and had no text in the top left corner :

  [Parsed_drawtext_0 @ 0000000003e54ea0] %{t} is not known 0B f=0/0

  So does the current time variable just not work in drawtext ?
  Is there another way to write the current frame on the video or even on the console window ?

  Using Windows 10 Enterprise and the latest build of ffplay for windows at this time.