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• JavaCV Fetch RTSP Meet "avcodec_open2() error -40 : Could not open audio codec" Error

  6 avril 2019, par Jeremy Lu

  I am trying to use javacv to fetch a rtsp monitoring camera and grabber the frames, but meet "avcodec_open2() error -40 : Could not open audio codec" error when the grabber is prepare to start after setup the parameters.

  Javacv version :

  • org.bytedeco.javacv-platform, 1.4.1
  • org.bytedeco.javacpp-presets.opencv-platform, 3.4.1-1.4.1

  Here is the Jave Exception Infomation :

  org.bytedeco.javacv.FrameGrabber$Exception: avcodec_open2() error -40: Could not open audio codec.  
  
    at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:835) ~[javacv-1.4.1.jar:1.4.1]  
  
    at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:663) ~[javacv-1.4.1.jar:1.4.1]  

  rtsp infomation :
  For the rtsp source, I also tried to download the FFplay and use command

  .\ffplay.exe -rtsp_transport tcp rtsp://admin:DWUUUP@10.193.8.71

  to show the frames from monitoring camera, and it works, and with following information

  • Input #0, rtsp, from ’rtsp ://admin:DWUUUP@10.193.8.71’ :

    • Metadata :
      • title : Media Presentation
    • Duration : N/A, start : 0.000000, bitrate : N/A
      • Stream #0:0 : Video : h264 (Main), yuvj420p(pc, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 15 fps, 24.17 tbr, 90k tbn, 30 tbc
      • Stream #0:1 : Audio : aac, 16000 Hz, 1 channels, fltp

  • [aac @ 000001fc123be880] Audio object type 0 is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.

  And here is the source code :

  FFmpegFrameGrabber grabber = new FFmpegFrameGrabber ("rtsp://admin:DWUUUP@10.193.8.71");
  
  grabber.setImageHeight(640);
  
  grabber.setImageWidth(360);
  
  grabber.setOption("rtsp_transport", "tcp");
  
  grabber.start(); // Where meet the problem
  
  
  
  Java2DFrameConverter converter = new Java2DFrameConverter();
  
  BufferedImage bufferedImage = converter.convert( grabber.grab() );
  
  ByteArrayOutputStream bateArrayOutputStream = new ByteArrayOutputStream();
  
  ImageIO.write(bufferedImage, "jpeg", bateArrayOutputStream);
  
  byte[] data = bateArrayOutputStream.toByteArray();
  
  bateArrayOutputStream.close();

  I have tested to change the rtsp to a mp4 file, the code can work.

  How can I fix this problem ? Thanks very much !

• App engine php flex env exec("ffmpeg...") - Unable to open logfile : /dev/stderr

  15 octobre 2018, par dan

  I’m trying to run FFMPEG on the app engine flex env for php.

  I’ve whitelisted the exec() function in my app.yaml and installed FFMPEG using the docker file - so far so good.

  When I’m running a exec("usr/bin/ffmpeg [args]...") I get an error that ffmpeg can’t access the dev/stderr and the function shuts down. see ref :

  WARNING : [pool app] child 44 said into stderr : "NOTICE : PHP message : ALERT - Unable to open logfile : /dev/stderr (attacker ’’, file ’/app/index.php’, line 49)"

  WARNING : [pool app] child 44 said into stderr : "NOTICE : PHP message : PHP Warning : exec() has been disabled for security reasons in /app/index.php on line 49"

  My configuration files are as follows :

  APP.YAML :

  runtime: custom
  
  env: flex
  
  runtime_config:
  
    document_root: .

  COMPOSER.JSON :

  {
  
      "require": {
  
          "php": "5.6.*",
  
          "google/cloud-storage": "^1.0",
  
      }
  
  }

  DOCKERFILE :

  FROM gcr.io/google-appengine/php:latest
  
  ENV DOCUMENT_ROOT /app
  
  RUN apt-get -y update && apt-get install -y ffmpeg

  INDEX.PHP :

  <?php
  
  //downloaded images into /tmp folder
  
  $cmd = "/usr/bin/ffmpeg -r 24 -i /tmp/frame_%05d.png -r 24 -vcodec libx264 -pix_fmt yuv420p -b 50M -s 1920x1080 -y /tmp/export.mp4";
  
  exec($cmd);
  
  ?>

  I’ve tried using all the other shell function - system(), exec_shell(),proc_open()
  With the same result.

  Any help ?

  Thank you

• Cannot open ".mp4" video files using OpenCV 2.4.3, Python 2.7 in Windows 7 machine

  24 octobre 2017, par TJ Monserrat

  I am currently working on a project that involves reading mp4 video files.
  The problem I encountered is that it using Python 2.7 (32 bit), OpenCV 2.4.3 (cv2.pyd) in a Windows 7 machine.

  The code snippet is as follows :

  try:
  
          video = cv2.VideoCapture("video.mp4")
  
  except:
  
          print "Could not open video file"
  
          raise
  
  print video.grab()

  "video.grab()" always returns false : meaning it doesn’t read the file "video.mp4"
  But when we try this :

  try:
  
          video = cv2.VideoCapture("video.avi")
  
  except:
  
          print "Could not open video file"
  
          raise
  
  print video.grab()

  "video.grab()" returns true : meaning it is able to read ".avi" files.

  Another is we have tried this same snippet on Linux and Mac and it seems to work fine, meaning it is able to read both mp4 files and avi files.

  This problem is similar to this problem and this problem. Both still don’t have a clear and workable answer.

  I would appreciate any help or workaround aside from just using Linux or Mac for programming this as I need this to work on all three systems.