Recherche avancée

Sur d’autres sites (12705)

• http: Support setting custom User-Agent

  6 mars 2014, par Clément Bœsch

  http: Support setting custom User-Agent
  Contextually make the default User-Agent use the common
  
  "Name/Version" pattern.
  Signed-off-by : Luca Barbato <lu_zero@gentoo.org>
  

  • [DBH] doc/protocols.texi
  • [DBH] libavformat/http.c

• Custom Reading Function for FFMPEG I/O

  20 septembre 2015, par Joe Allen

  I need to create a custom reading callback function that can read contents of a file in the form of a std::string into a uint8_t * buf. I tried multiple different methods found around the internet and on stackoverflow but sometimes it works and other the the program infinitely loops or stops execution half way.

  I have no problems with amr/3gp files but all wav/pcm files are causing some problems for some reason. All I know its something to do with the reading function I have so far.

  Ideally I would like to be able to give the program any type of file and then it converts it.

  This is how I am calling the readCallback function from the code :

  //create the buffer
  
  uint8_t * avio_ctx_buffer = NULL;
  
  
  
  //allocate space for the buffer using ffmpeg allocation method
  
  avio_ctx_buffer = (uint8_t *) av_malloc(avio_ctx_buffer_size);
  
  
  
  //Allocate and initialize an AVIOContext for buffered I/O.
  
  //audio variable contains the contents of the audio file
  
  avio_ctx = avio_alloc_context(avio_ctx_buffer, avio_ctx_buffer_size,0, &audio, &readCallback, NULL, NULL);

  Here is the callback function that works on some types of files :

  static int readCallback(void* opaque, uint8_t * buf, int buf_size){  
  
    std::string * file =static_cast(opaque);
  
    if(file->length() == 0){
  
     return AVERROR_EOF; //if we reach to the end of the string, return
  
                         // return End of file
  
    }
  
  
  
    // Creating a vector of the string size
  
    std::vector array(file->length());
  
  
  
    //Copying the contents of the string into the vector
  
    std::copy(file->begin(),file->end(),array.begin());
  
  
  
    //Copying the vector into buf
  
    std::copy(array.begin(),array.end(),buf);
  
  
  
  
  
    return file->length();
  
  
  
  }

• Why would a custom ffmpeg filter fail unless -threads=1 ?

  20 février 2018, par headdab

  I’m developing a filter I derived from vf_codecview, using a current ffmpeg tree and my filter doesn’t work correctly unless I add -threads=1 to the command line.

  I’ve read what I can find about writing ffmpeg filters, including doc/writing_filters.txt, but can’t figure out what might be going wrong.
  I’m not using the filter_slice() ideas mentioned therein, either.

  Are there any new, undocumented behaviors that affect how filters are run ?