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• OpenCV Reporting TBR instead of FPS when using capture.get(CV_CAP_PROP_FPS)

  22 février 2012, par Malife

  I have several videos that I am trying to process using OpenCV and Qt 4.7.4 on Mac OS 10.6.8 (Snow Leopard). If I create a cv::VideoCapture object and then query for the frame rate related to such video, what I get back is the TBR and not FPS.

  For instance if use ffprobe Video1.mp4 what I get is :

  >> ffprobe Video1.mp4      
  
  ffprobe version 0.7.8, Copyright (c) 2007-2011 the FFmpeg developers
  
  built on Nov 24 2011 14:31:00 with gcc 4.2.1 (Apple Inc. build 5666) (dot 3)
  
  configuration: --prefix=/opt/local --enable-gpl --enable-postproc --enable-swscale --   
  
  enable-avfilter --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-
  
  libdirac --enable-libschroedinger --enable-libopenjpeg --enable-libxvid --enable-libx264 
  
  --enable-libvpx --enable-libspeex --mandir=/opt/local/share/man --enable-shared --
  
  enable-pthreads --cc=/usr/bin/gcc-4.2 --arch=x86_64 --enable-yasm
  
  libavutil    50. 43. 0 / 50. 43. 0
  
  libavcodec   52.123. 0 / 52.123. 0
  
  libavformat  52.111. 0 / 52.111. 0
  
  libavdevice  52.  5. 0 / 52.  5. 0
  
  libavfilter   1. 80. 0 /  1. 80. 0
  
  libswscale    0. 14. 1 /  0. 14. 1
  
  libpostproc  51.  2. 0 / 51.  2. 0
  
  
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Video1.mp4':
  
  Metadata:
  
  major_brand     : isom
  
  minor_version   : 0
  
  compatible_brands: mp41avc1qt  
  
  creation_time   : 2012-01-09 23:09:43
  
  encoder         : vlc 1.1.3 stream output
  
  encoder-eng     : vlc 1.1.3 stream output
  
  Duration: 00:10:10.22, start: 0.000000, bitrate: 800 kb/s
  
  Stream #0.0(eng): Video: h264 (Baseline), yuvj420p, 704x480 [PAR 10:11 DAR 4:3], 798 
  
  kb/s, 27.71 fps, 1001 tbr, 1001 tbn, 2002 tbc
  
  Metadata:
  
    creation_time   : 2012-01-09 23:09:43

  Which correctly reports FPS = 27.71 and TBR = 1001. Nevertheless if I use the following OpenCV code to query for the FPS :

  QString filename = QFileDialog::getOpenFileName(this,
  
                                          "Open Video",
  
                                          "Video Files (*.mp4, *.mpg)");
  
  
  
  capture.release();
  
  capture.open(filename.toAscii().data());
  
  
  
  if (!capture.isOpened()){
  
      qDebug() <<"Error when opening the video!";
  
      return;
  
  }
  
  
  
  
  
  qDebug() << "Frame Rate:" << capture.get(CV_CAP_PROP_FPS);
  
  qDebug() << "Num of Frames:" << capture.get(CV_CAP_PROP_FRAME_COUNT);
  
  qDebug() << "OpenCV Version" << CV_VERSION;

  The output I get is :

  Frame Rate: 1001 
  
  Num of Frames: 610832 
  
  OpenCV Version 2.3.1 

  Which reports the TBR instead of the FPS. This behavior is consistent when I try to open different videos.

  I checked OpenCV's bug tracker and I also found this stack overflow question to be a similar but not quite the same problem, so I am at a loss to what to do next. Any hint or idea is most welcome since I've tried lots of things and seem to be getting nowhere.

• ffmpeg invalid data found when processing input

  28 février 2012, par user1222905

  I did download the .tar.gz for ffmpeg 0.10. I am trying to convert a file called message.h263 to output.mp4. I did : "ffmpeg -i message.h263 -vcodec libx264 -acodec libfaac -f mov out.mp4" the result I get is :

  ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  
    built on Feb 28 2012 15:11:37 with gcc 4.4.5
  
    configuration: 
  
    libavutil      51. 34.101 / 51. 34.101
  
    libavcodec     53. 60.100 / 53. 60.100
  
    libavformat    53. 31.100 / 53. 31.100
  
    libavdevice    53.  4.100 / 53.  4.100
  
    libavfilter     2. 60.100 /  2. 60.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0.  6.100 /  0.  6.100
  
  message.h263: Invalid data found when processing input

  HOW TO SOLVE THIS ? I am new to this stuff and i can ;t seem to get it out. I spend all my day solving this with no result. I am working under Ubuntu 10.10. Need help. Thx appreciate.

• Who can tell me the difference and relation between ffmpeg, libav, and avconv

  25 septembre 2014, par why

  when I run ffmpeg on Ubuntu, it shows :

  $ ffmpeg 
  
  ffmpeg version v0.8, Copyright (c) 2000-2011 the Libav developers
  
    built on Feb 28 2012 13:27:36 with gcc 4.6.1
  
  This program is not developed anymore and is only provided for compatibility. Use avconv instead (see Changelog for the list of incompatible changes).

  or it shows (depending on Ubuntu version) :

  $ ffmpeg
  
  ffmpeg version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers
  
    built on Jan 24 2013 14:49:20 with gcc 4.7.2
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.

  I found avconv on http://libav.org, I am just perplexed by them