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• Problems loading G.729 decoder with FFmpeg API

  20 juillet 2015, par gapc

  I built a class with the use of the FFmpeg API to decode several audio files (mp3, ogg, G.729, etc) and load them into a data structure as raw audio data. Now for example when I run the following code :

  codec = avcodec_find_decoder(AV_CODEC_ID_G729);
  
  if (codec == NULL){
  
      printf("Codec not found");
  
      exit(1);
  
  }

  The program will indeed output the error message, but if I load mp3 or ogg codecs there’s no issue.

  So to double check I executed in the terminal ffmpeg -decoders to see if the decoder is supported (which I also checked online) and outputs :

  A....D g729                 G.729

  I need the decoder for G.729. Is there anything I’m missing or doing something wrong ? Is there a different way to load this decoder ? Any suggestions would be greatly appreciated.

  The FFmpeg version installed is 2.7.1 on a Debian system

  API use example : https://www.ffmpeg.org/doxygen/2.7/decoding_encoding_8c-example.html

• Using ffmpeg ffprobe with Visual C++

  11 juillet 2015, par astracat111

  I have the following command line that gives me the duration of a video file :

  ffprobe.exe -i Video.mp4 show_entries format=duration -v quiet -of csv="p=0"

  When I run this, I get back the duration of my video successfully, running it from a command prompt. Now, I’m kind of a beginner with C++, so I’m not sure how I could get that duration to be put into a float inside of my program. I’ve looked through a lot of articles and question and answer forums online and I’ve found possible answers with...using stdout/stdin to grab the information...? I’m not sure.

  My strategy right now is to use CreateProcess() to run the process, then WaitForSingleObject(), then somehow use some command to grab the output data from the ffprobe process. Perhaps the data I’m looking for can be retrieved through the CreateProcess() function ? I feel like I’m very close, but I’m in serious need of help with this...

  As a side note, since I’m using Visual C++ Express 2010, I do not have access to MFC.

  If anyone could lead me in the right direction to this information it would be greatly appreciated.

• FFmpeg can't access file in Dropbox on Ubuntu 12.04

  30 juin 2015, par afterglowlee

  I have installed FFmpeg on Ubuntu 12.04. When I use ffmpeg -i command to check some video file online, it works :

  ffmpeg -i http://techslides.com/demos/sample-videos/small.mp4

  However, when I check a public file hosted in my Dropbox it gives ’No such file or directory error’ :

  ffmpeg -i https://dl.dropboxusercontent.com/u/51617581/bigbuck.webm

  and the error is :

  https://dl.dropboxusercontent.com/u/51617581/bigbuck.webm : No such
  file or directory

  and here is the version info of the ffmpeg installation :

  ffmpeg version 0.8.17-4:0.8.17-0ubuntu0.12.04.1, Copyright (c)
  2000-2014 the Libav developers built on Mar 16 2015 13:26:50 with
  gcc 4.6.3

  I have also tried both files on my Mac 10.10 laptop, and both of them work fine. Could anyone suggest where is the problem ? Many thanks.