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• avcodec/cavsdec : Check frame_rate_code

  14 mai 2015, par Michael Niedermayer

  avcodec/cavsdec : Check frame_rate_code
  Fixes CID1239111 part1
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/cavsdec.c

• Recording screencast using ffmpeg produces audio that is out of sync with the video

  7 décembre 2014, par AgilE

  I’m on Fedora 20. I got it pre-compiled from the repo.

  I use the follow command to record screencasts :

  ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1366x768 -i :0.0 -acodec pcm_s16le -vcodec libx264 -preset ultrafast -crf 0 -threads 0 filename.mkv

  The audio is perfectly synced with the video at the beginning. However, as the video progresses, the audio starts lagging behind severely (say a lag of more than 4 seconds). I’ve included a sample output that ffmpeg shows while recording a video.

  ffmpeg version 2.1.3 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Jan 25 2014 15:11:42 with gcc 4.8.2 (GCC) 20131212 (Red Hat 4.8.2-7)
  
    configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-frei0r --enable-gnutls --enable-libass --enable-libcdio --enable-libcelt --enable-libdc1394 --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopencv --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect
  
    libavutil      52. 48.101 / 52. 48.101
  
    libavcodec     55. 39.101 / 55. 39.101
  
    libavformat    55. 19.104 / 55. 19.104
  
    libavdevice    55.  5.100 / 55.  5.100
  
    libavfilter     3. 90.100 /  3. 90.100
  
    libavresample   1.  1.  0 /  1.  1.  0
  
    libswscale      2.  5.101 /  2.  5.101
  
    libswresample   0. 17.104 /  0. 17.104
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Guessed Channel Layout for  Input Stream #0.0 : stereo
  
  Input #0, alsa, from 'pulse':
  
    Duration: N/A, start: 1391533629.323015, bitrate: 1536 kb/s
  
      Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
  
  [x11grab @ 0x153ad80] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1366 height: 768
  
  [x11grab @ 0x153ad80] shared memory extension found
  
  Input #1, x11grab, from ':0.0':
  
    Duration: N/A, start: 1391533629.365274, bitrate: 1007124 kb/s
  
      Stream #1:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1366x768, 1007124 kb/s, 30 tbr, 1000k tbn, 30 tbc
  
  [swscaler @ 0x1520460] deprecated pixel format used, make sure you did set range correctly
  
  No pixel format specified, yuv444p for H.264 encoding chosen.
  
  Use -pix_fmt yuv420p for compatibility with outdated media players.
  
  [libx264 @ 0x1551420] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
  [libx264 @ 0x1551420] profile High 4:4:4 Predictive, level 3.2, 4:4:4 8-bit
  
  [libx264 @ 0x1551420] 264 - core 138 r2363 c628e3b - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=0 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=cqp mbtree=0 qp=0
  
  Output #0, matroska, to 'testing.mkv':
  
    Metadata:
  
      encoder         : Lavf55.19.104
  
      Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p, 1366x768, q=-1--1, 1k tbn, 30 tbc
  
      Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s
  
  Stream mapping:
  
    Stream #1:0 -> #0:0 (rawvideo -> libx264)
  
    Stream #0:0 -> #0:1 (pcm_s16le -> pcm_s16le)
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x1520460] Warning: data is not aligned! This can lead to a speedloss
  
  frame=  213 fps= 27 q=-1.0 Lsize=    3572kB time=00:00:08.00 bitrate=3653.6kbits/s    
  
  video:2025kB audio:1501kB subtitle:0 global headers:0kB muxing overhead 1.291094%
  
  [libx264 @ 0x1551420] frame I:1     Avg QP: 0.00  size:692585
  
  [libx264 @ 0x1551420] frame P:212   Avg QP: 0.00  size:  6509
  
  [libx264 @ 0x1551420] mb I  I16..4: 100.0%  0.0%  0.0%
  
  [libx264 @ 0x1551420] mb P  I16..4: 47.2%  0.0%  0.0%  P16..4:  0.1%  0.0%  0.0%  0.0%  0.0%    skip:52.8%
  
  [libx264 @ 0x1551420] coded y,u,v intra: 0.7% 0.7% 0.7% inter: 0.1% 0.1% 0.1%
  
  [libx264 @ 0x1551420] i16 v,h,dc,p: 100%  0%  0%  0%
  
  [libx264 @ 0x1551420] kb/s:2335.32

  Is there something I’m missing ?

• How to extract image frames from a bagfile ?

  12 mars 2014, par Leyonce

  I am using ROS hydro on Ubuntu 12.04. After using the command "rosrun image_view extract_images _sec_per_frame :=0.01 image :=IMAGE_TOPIC_IN_BAGFILE" I'm having an error when executing"ffmpeg -r -b -i frame%04d.jpg .avi" The thing is I am not seeing the sequence of images after I play the bagfile.I ran "rosbag info" to obtain the topic in the bag file but when I run "rosrun rqtgraph rqtgraph" the /extract_image frame node is there all by itself.

  When I follow the tutorials on http://wiki.ros.org/rosbag/Tutorials/... I get an error " [FATAL] [1394583654.335465840] : Error opening file : play".After replacing play by "--clock" everything seemed to go just fine but there are no frames*.jpg in /home/.ros hence the sequence of images are still missing. I feel like I'm lacking something.Can anyone help ?