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• Opening file with unknown extension (Mjpeg ?) in OpenCV python

  14 novembre 2013, par bw4sz

  I am trying to open a third party video file into OpenCV with python.
  My camera (plotwatcher camera trap) shoots in a silly proprietary format. The extension is unique (.tlv) but i can play the file in VLC, and using ffmpeg i can see the following encoding :

  C:\Users\Ben>ffmpeg -i C:/Users/Ben/Documents/OpenCV_HummingbirdsMotion/PlotwatcherTest.tlv
  
  
  
  ffmpeg version N-58037-g355cea8 Copyright (c) 2000-2013 the FFmpeg developers
  
  built on Nov 11 2013 18:01:42 with gcc 4.8.2 (GCC)
  
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
  
  isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
  
  le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
  
  e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
  
  ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
  
  ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
  
  eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aa
  
  cenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavp
  
  ack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  
  libavutil      52. 52.100 / 52. 52.100
  
  libavcodec     55. 41.100 / 55. 41.100
  
  libavformat    55. 21.100 / 55. 21.100
  
  libavdevice    55.  5.100 / 55.  5.100
  
  libavfilter     3. 90.102 /  3. 90.102
  
  libswscale      2.  5.101 /  2.  5.101
  
  libswresample   0. 17.104 /  0. 17.104
  
  libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, avi, from 'C:/Users/Ben/Documents/OpenCV_HummingbirdsMotion/Plotwatche
  
  rTest.tlv':
  
  Duration: 00:00:05.00, start: 0.000000, bitrate: 14608 kb/s
  
  Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc), 1280x720, 10 tb
  
  r, 10 tbn, 10 tbc

  From this i can see file is encoded into mjpeg format.

  How can i open this file in open cv ?

  import cv2
  
  #import cv2.cv as cv
  
  import numpy as np
  
  cap = cv2.VideoCapture("C:/Users/Ben/Documents/OpenCV_HummingbirdsMotion/PlotwatcherTest.mjpg")
  
  ret, frame = cap.read()
  
  #show first image
  
  cv2.imshow('my window',frame)
  
  cv2.waitKey(0)
  
  cv2.destroyWindow('my window')

  I can see nothing has been loaded. When i try to view the first frame i get the error :

  File "C:\Users\Ben\Documents\OpenCV_HummingbirdsMotion\Test.py", line 21, in <module>
  
  cv2.imshow(&#39;my window&#39;,frame)
  
  error: ..\..\..\..\opencv\modules\highgui\src\window.cpp:261: error: (-215)
  
  size.width>0        &amp;&amp; size.height>0
  
  </module>

  I've tried leaving the native .tlv, mjpeg and mjpg, and .MJPG endings following the conceptual idea found here : MJPEG stream fails to open in OpenCV 2.4

  i appreciate all help !

• Changing portrait videos to landscape aspect with latest ffmpeg release is breaking

  19 décembre 2016, par zeal

  I am having an issue scaling videos recorded in portrait with the latest version of ffmpeg (2.1). This worked fine in a previous version, but I need the lastest version to fix a different issue.

  I am trying to take any video passed and make it 852 wide by 480 high. It works fine when converting videos that are wider then tall, but when the video is taller then wide it corrupts the video. It actually adds a letter box to the top and bottom, rather then left and right. Also, the meta data shows it as the correct height & width, but its wrong when played in windows.

  Here are the parameters I am using.

  ffmpeg -i INPUT -s 852x480 -r 30 -aspect 1.775 -b:v 2000000 -vcodec mpeg4 -vf "scale=iw*min(852/iw\,480 /ih):ih*min(852/iw\,480 /ih),pad=852:480 :(852-iw)/2:(480 -ih)/2" -ac 2 -b:a 128k -ar 44100 -y OUTPUT

  Console output from ffmpeg -i INPUT -r 30 -b:v 2000000 -vcodec mpeg4 -vf "scale=852:480" -ac 2 -b:a 128k -ar 44100 -y OUTPUT :

  C:\Lib>ffmpeg -i "d\ca96cd13-2995-4794-b753-22be3b918659.mov" -r 30 -b:v 2000000 -vcodec mpeg4 -vf "
  
  scale=852:480" -ac 2 -b:a 128k -ar 44100 -y "d\portx.mp4"
  
  ffmpeg version N-58015-g8cdf4e0 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Nov 10 2013 18:04:45 with gcc 4.8.2 (GCC)
  
    configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32thread
  
  s --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-icon
  
  v --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-
  
  libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrw
  
  b --enable-libopenjpeg --enable-libopus --enable-librtmp --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-libx264 --enab
  
  le-libxavs --enable-libxvid --enable-zlib
  
    libavutil      52. 52.100 / 52. 52.100
  
    libavcodec     55. 41.100 / 55. 41.100
  
    libavformat    55. 21.100 / 55. 21.100
  
    libavdevice    55.  5.100 / 55.  5.100
  
    libavfilter     3. 90.102 /  3. 90.102
  
    libswscale      2.  5.101 /  2.  5.101
  
    libswresample   0. 17.104 /  0. 17.104
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'd\ca96cd13-2995-4794-b753-22be3b918659.mov':
  
    Metadata:
  
      major_brand     : qt
  
      minor_version   : 0
  
      compatible_brands: qt
  
      creation_time   : 2013-11-12 15:02:21
  
      model           : iPhone 5
  
      model-eng       : iPhone 5
  
      encoder         : 7.0.2
  
      encoder-eng     : 7.0.2
  
      date            : 2013-11-12T10:02:21-0500
  
      date-eng        : 2013-11-12T10:02:21-0500
  
      make            : Apple
  
      make-eng        : Apple
  
    Duration: 00:00:15.48, start: 0.000000, bitrate: 780 kb/s
  
      Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 480x360, 7
  
  05 kb/s, 29.98 fps, 30 tbr, 600 tbn, 1200 tbc (default)
  
      Metadata:
  
        rotate          : 90
  
        creation_time   : 2013-11-12 15:02:21
  
        handler_name    : Core Media Data Handler
  
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 62 kb/s (default)
  
      Metadata:
  
        creation_time   : 2013-11-12 15:02:21
  
        handler_name    : Core Media Data Handler
  
  Output #0, mp4, to 'd\portx.mp4':
  
    Metadata:
  
      major_brand     : qt
  
      minor_version   : 0
  
      compatible_brands: qt
  
      make-eng        : Apple
  
      model           : iPhone 5
  
      model-eng       : iPhone 5
  
      make            : Apple
  
      encoder-eng     : 7.0.2
  
      date            : 2013-11-12T10:02:21-0500
  
      date-eng        : 2013-11-12T10:02:21-0500
  
      encoder         : Lavf55.21.100
  
      Stream #0:0(und): Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 852x480, q=2-31, 2000 kb/s, 15360
  
   tbn, 30 tbc (default)
  
      Metadata:
  
        rotate          : 90
  
        creation_time   : 2013-11-12 15:02:21
  
        handler_name    : Core Media Data Handler
  
      Stream #0:1(und): Audio: aac (libvo_aacenc) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, s16, 128
  
   kb/s (default)
  
      Metadata:
  
        creation_time   : 2013-11-12 15:02:21
  
        handler_name    : Core Media Data Handler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> mpeg4)
  
    Stream #0:1 -> #0:1 (aac -> libvo_aacenc)
  
  Press [q] to stop, [?] for help
  
  frame=  465 fps=417 q=3.8 Lsize=    4118kB time=00:00:15.52 bitrate=2173.3kbits/s
  
  video:3860kB audio:243kB subtitle:0 global headers:0kB muxing overhead 0.348231%

• configure : Check whether MSVC requires using the C89-to-C99 converter

  4 novembre 2013, par Martin Storsjö

  configure : Check whether MSVC requires using the C89-to-C99 converter
  MSVC does support enough of C99 to work without the converter since
  
  the 2013 version. Try to detect which version of the compiler in
  
  the path needs to run the C99 converter or not. When the converter
  
  is omitted, compilation time is reduced quite drastically.
  Prior to this, users could still use —cc="c99conv -noconv cl"
  
  when running MSVC 2013 to achieve the same.
  This checks the version number instead of doing a normal compile
  
  test, since this check needs to be done earlier in configure, before
  
  the normal compile test helpers are usable.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] configure