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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 
  cv2.imshow('my window',frame)
  error: ..\..\..\..\opencv\modules\highgui\src\window.cpp:261: error: (-215)
  size.width>0        && size.height>0
  

  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!

• iOS FFmpeg : Requested output format 'flv' is not a suitable output format

  14 novembre 2013, par user2992563

  I just upgraded my iOS compiled FFmpeg library to 1.2.1 and now I'm getting the following error message: Requested output format 'flv' is not a suitable output format.

  I tried changing format to 'avi' and 'mov' aswell, but it seems that no matter the format_name I pass I get the same error message.

  This is how I set up the format_name:

  avformat_alloc_output_context2(&file, NULL, "flv", cname)
  

  And this is how I write the stream packets:

  // Appends a data packet to the rtmp stream
  -(bool) writePacket: (Demuxer *) source
  {
  int code = 0;
  
  AVCodecContext
  *videoCodec = [source videoCodec],
  *audioCodec = [source audioCodec];
  
  // Write headers
  if(useHeaders)
  {
      AVStream
      *video = av_new_stream(file, VIDEO_STREAM),
      *audio = av_new_stream(file, AUDIO_STREAM);
  
      if (!video || !audio)
          @throw [NSException exceptionWithName: @"StreamingError" reason: @"Could not allocate streams" userInfo: nil];
  
      // Clone input codecs and extra data
      memcpy(video->codec, videoCodec, sizeof(AVCodecContext));
      memcpy(audio->codec, audioCodec, sizeof(AVCodecContext));
  
      video->codec->extradata = av_malloc(video->codec->extradata_size);
      audio->codec->extradata = av_malloc(audio->codec->extradata_size);
  
      memcpy(video->codec->extradata, videoCodec->extradata, video->codec->extradata_size);
      memcpy(audio->codec->extradata, audioCodec->extradata, audio->codec->extradata_size);
  
      // Use FLV codec tags
      video->codec->codec_tag = FLV_TAG_TYPE_VIDEO;
      audio->codec->codec_tag = FLV_TAG_TYPE_AUDIO;
      video->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
      video->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
      audio->codec->sample_rate = INPUT_AUDIO_SAMPLING_RATE;
  
      // Update time base
      video->codec->time_base.num = 1;
      audio->codec->time_base.den = video->codec->time_base.den = FLV_TIMEBASE;
  
      // Signal bitwise stream copying
      //video->stream_copy = audio->stream_copy = 1;
  
      if((code = avformat_write_header(file, NULL)))
          @throw [NSException exceptionWithName: @"StreamingError" reason: @"Could not write stream headers" userInfo: nil];
      useHeaders = NO;
  }
  bool isVideo;
  AVPacket *packet = [source readPacket: &isVideo];
  
  if(!packet)
      return NO;
  
  if(isVideo)
  {
      packet->stream_index = VIDEO_STREAM;
      packet->dts = packet->pts = videoPosition;
      videoPosition += packet->duration = FLV_TIMEBASE * packet->duration * videoCodec->ticks_per_frame * videoCodec->time_base.num / videoCodec->time_base.den;
  }
  else
  {
      packet->stream_index = AUDIO_STREAM;
      packet->dts = packet->pts = audioPosition;
      audioPosition += packet->duration = FLV_TIMEBASE * packet->duration / INPUT_AUDIO_SAMPLING_RATE;
  }
  
  packet->pos = -1;
  packet->convergence_duration = AV_NOPTS_VALUE;
  
  // This sometimes fails without being a critical error, so no exception is raised
  if((code = av_interleaved_write_frame(file, packet)))
      NSLog(@"Streamer::Couldn't write frame");
  
  av_free_packet(packet);
  return YES;
  }
  

  In the code above I had to comment out this line as stream_copy has been removed from the newest version of FFmpeg:

  video->stream_copy = audio->stream_copy = 1;
  

  Any help would be greatly appreciated!

• Connecting to RTSP stream via FFMpeg - 'could not find codec parameters for stream 0'

  14 novembre 2013, par user2992545

  I'm a beginner in the FFMpeg world, so please excuse me my overall level of knowledge and any mistakes.

  What I have here is a DVR, made by ITX Security. I have an SDK for it and currently I'm trying to connect to its RTSP using FFMPEG. I've been partially succesfull (i think), the best what I got was:

  `(...)bin>ffplay -user-agent "ITX Security" rtsp://ADMIN:1234@192.168.2.130:5554/live/
  
  [rtsp @ 02a242e0] UDP timeout, retrying with TCPB sq=0B f=0/0
  [rtsp @ 02a242e0] method PAUSE failed: 501 Not Implemented
  [rtsp @ 02a242e0] Could not find codec parameters for stream 0 (Video: h264):unspecified size Consider increasing the value for the 'analyzeduration' and 'probesize' options
  rtsp://ADMIN:1234@192.168.2.130:5554/live/: could not find codec parameters
  
  nan:  0.000 fd=0 aq=    0KB vq=    0KB sq=    0B f=0/0`
  

  Is it really indicating that it has trouble in playing the stream (because it lacks a proper codec?) - or am I just not getting the point?

  I've captured traffic between my computer and the DVR in question, and something is happening (at least that's what Wireshark says).

  https://www.dropbox.com/s/j65lige244kg8jt/rtsp_ffmpeg.pcap

  What am I doing wrong?

  Regards.

• ffmpeg minimal requirements configuration for encoding and decoding h264 files

  14 novembre 2013, par TheSquad

  I'm trying to compile ffmpeg with minimal requirements in order to encode/decode with h264.

  So far my command line configuration is :

  ./configure --disable-yasm --disable-everything --enable-encoder=libx264 --enable-encoder=libfaac --enable-decoder=h264 --enable-muxer=h264 --enable-demuxer=h264 --enable-parser=h264 --enable-protocol=file
  

  once compiled, I try this :

  ./ffmpeg -i ~/Dropbox/TestFile.mov -vcodec libx264 test.mp4
  

  but I get an error :

    ffmpeg version N-58081-g2925571 Copyright (c) 2000-2013 the FFmpeg developers
    built on Nov 14 2013 15:49:58 with Apple LLVM version 5.0 (clang-500.2.76) (based on LLVM 3.3svn)
    configuration: --disable-yasm --disable-everything --enable-encoder=libx264 --enable-encoder=libfaac --enable-decoder=h264 --enable-muxer=h264 --enable-demuxer=h264 --enable-parser=h264 --enable-protocol=file
    libavutil      52. 52.100 / 52. 52.100
    libavcodec     55. 43.100 / 55. 43.100
    libavformat    55. 21.100 / 55. 21.100
    libavdevice    55.  5.100 / 55.  5.100
    libavfilter     3. 91.100 /  3. 91.100
    libswscale      2.  5.101 /  2.  5.101
    libswresample   0. 17.104 /  0. 17.104
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/mGs/Dropbox/TestFile.mov':
    Metadata:
      major_brand     : qt  
      minor_version   : 0
      compatible_brands: qt  
      creation_time   : 2013-06-23 14:33:09
      model           : iPhone 4S
      model-fra       : iPhone 4S
      encoder         : 6.0
      encoder-fra     : 6.0
      date            : 2013-06-23T16:33:09+0200
      date-fra        : 2013-06-23T16:33:09+0200
      make            : Apple
      make-fra        : Apple
    Duration: 00:00:42.09, start: 0.000000, bitrate: 20960 kb/s
      Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080, 20880 kb/s, 29.97 fps, 29.97 tbr, 600 tbn, 1200 tbc (default)
      Metadata:
        rotate          : 180
        creation_time   : 2013-06-23 14:33:09
        handler_name    : Core Media Data Handler
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, 63 kb/s (default)
      Metadata:
        creation_time   : 2013-06-23 14:33:09
        handler_name    : Core Media Data Handler
  [NULL @ 0x7fd999802e00] Unable to find a suitable output format for 'test.mp4'
  test.mp4: Invalid argument
  

  This is probably coming from the fact that I have forgot something to enable on the ffmpeg configuration... But I can't found out what.

  The test file is a video got from iPhone 4S Camera.

• Video Concatnation using javacv

  14 novembre 2013, par bindal

  I have integrated this Javacv for concatenating 2 videos this code works find when i was using 2 videos recorded from rear camera,but when i record 1 video with front cameara and another with rear camera then another half video is rotated upside down Is there any specific settings while recording from front camera,

  I have used this library from github https://github.com/sourab-sharma/TouchToRecord

  Here is the recording file Video Recording

  Please give me some solution on this

  Thanks