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• iPhone - IMA WAV ADPCM audio stream for iOS

  21 mai 2013, par Siriss

  I am trying to write an app for a school project that will play a video stream of the lab. They use Foscam cameras, and from what I understand they only stream audio in FFMPEG and VLC (a wrapper of FFMPEG and others, correct ?). I can play the video stream in a UIWebView just fine, but I can't figure out how to get audio to work. I have read a bunch of post on here about the different audio stream options, but none support this format. I have also looked into VLCKit, but that seems to only work in OS X, not iOS.

  Is there a Framework, or Kit that can stream IMA WAV ADPCM audio from a VLC/FFMPEG file, or does someone know of a better way to get audio from a Foscam ?

  EDIT - I know more about the stream and I have tried a few things. I tried AVPlayer, but discovered Audio FIle Stream and Audio Queue Services but can't find a good tutorial.

  I also found THIS site, and tried the project with my stream and it did not work.

• How to get stream info from opened file in ffmpeg ?

  31 mai 2013, par Srv19

  I am trying to read video file using ffmpeg. I had working code that corresponded to somewhat old version of it, and started to try and upgrade to latest build version, exchanging all those deprecated functions for their actual analogues.

  However i have run into a problem. No streams seem to be retrieved and the load of video stops dead in tracks.

  here is the code i am using :

     // Open video file
  
     if(avformat_open_input(&pFormatCtx, filename.toStdString().c_str(), NULL, NULL)!=0)
  
         return FILE_NOT_OPENED; // Couldn't open file
  
  
  
     // Retrieve stream information
  
     if(avformat_find_stream_info(pFormatCtx,NULL)<0)
  
         return NO_STREAM_INFO; // Couldn't find stream information
  
  
  
     // Dump information about file onto standard error
  
     av_dump_format(pFormatCtx, 0, filename.toStdString().c_str(), false);
  
  
  
     // Find the first video stream
  
     videoStream=-1;
  
     for(unsigned i=0; inb_streams; i++)
  
         if(pFormatCtx->streams[i]->codec->codec_type==ffmpeg::AVMEDIA_TYPE_VIDEO)
  
         {
  
             videoStream=i;
  
             break;
  
         }
  
     if(videoStream==-1)
  
         return OTHER; // Didn't find a video stream
  
  
  
     // Get a pointer to the codec context for the video stream
  
     pCodecCtx=pFormatCtx->streams[videoStream]->codec;
  
  
  
     // Find the decoder for the video stream
  
     pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  
     if(pCodec==NULL)
  
         return CODEC_NOT_FOUND; // Codec not found
  
  
  
     // Open codec
  
     if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
  
         return CODEC_NOT_OPENED; // Could not open codec

  The problem arises in the cycle through video streams in ffmpeg::AVFormatContext *pFormatCtx. nb_streams field is 0, and i never actually enter the cycle, and codec is not loaded etc. Strange thing is, av_dump_format gives following output :

  License: GPL version 3 or later
  
  AVCodec version 3606372
  
  AVFormat configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  
  [asf @ 004e9540] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  Input #0, asf, from 'C:/Users/Public/Videos/Sample Videos/Wildlife.wmv':
  
    Metadata:
  
      SfOriginalFPS   : 299700
  
      WMFSDKVersion   : 11.0.6001.7000
  
      WMFSDKNeeded    : 0.0.0.0000
  
      comment         : Footage: Small World Productions, Inc; Tourism New Zealand | Producer: Gary F. Spradling | Music: Steve Ball
  
      title           : Wildlife in HD
  
      copyright       : В© 2008 Microsoft Corporation
  
      IsVBR           : 0
  
      DeviceConformanceTemplate: AP@L3
  
    Duration: 00:00:30.09, start: 0.000000, bitrate: 6977 kb/s
  
      Stream #0:0(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, 2 channels, fltp, 192 kb/s
  
      Stream #0:1(eng): Video: vc1 (Advanced) (WVC1 / 0x31435657), yuv420p, 1280x720, 5942 kb/s, 29.97 tbr, 1k tbn, 1k tbc

  and there are 2 streams, clear as day.

  I am utterly baffled. Please help.

• FFmpeg will not run from php

  15 mars 2015, par user2392940

  This is a live server i am on a Windows 2008 Web Edition R2 server with IIS7.

  I have tried all of this locally and it works perfectly. At first i thought this may have been a permisson issue i gave all ffmpeg folders and output folders full control. I also checked the php ini file to make sure exec is enabled.

  I was intially running the exec() function i later changed it to the system() function to see what ffmpeg was outputting. With the system() function it returns the error "Acess is denied". All of my research points to a IIS setting or Application Pool not having the correct permission. Any help would be much appreciated.

  FFmpeg location : C :\ffmpeg\bin\ffmpeg.exe

  I have been working on this for nearly a week even my server provider has no answer on why ffmpeg will not run from php. I believe this is a little deeper than full paths. It’s obviously a permission problem but the question is where is the permission problem ?

  It also seems that no .exe file can be executed from php.

  system ("$ffmpeg -i yourvideo/.mp4 -threads 1 -ss 20 -b 10k  -s 240x180 -vf fps=fps=1/20 -vframes 12 -aspect 4:3 thumbs/yourvideo/yourvideo.%01d.jpg 2>&1");