zoneminder/src/zm_ffmpeg_input.cpp

#include "zm_ffmpeg_input.h"
#include "zm_logger.h"
#include "zm_ffmpeg.h"

FFmpeg_Input::FFmpeg_Input() {
  input_format_context = NULL;
  video_stream_id = -1;
  audio_stream_id = -1;
}
FFmpeg_Input::~FFmpeg_Input() {
}

int FFmpeg_Input::Open( const char *filepath ) {

  int error;

  /** Open the input file to read from it. */
  if ((error = avformat_open_input( &input_format_context, filepath, NULL, NULL)) < 0) {

    Error("Could not open input file '%s' (error '%s')\n",
        filepath, av_make_error_string(error).c_str() );
    input_format_context = NULL;
    return error;
  } 

  /** Get information on the input file (number of streams etc.). */
  if ((error = avformat_find_stream_info( input_format_context, NULL)) < 0) {
    Error( "Could not open find stream info (error '%s')\n",
        av_make_error_string(error).c_str() );
    avformat_close_input(&input_format_context);
    return error;
  }

  for ( unsigned int i = 0; i < input_format_context->nb_streams; i += 1 ) {
    if ( is_video_stream( input_format_context->streams[i] ) ) {
      if ( video_stream_id == -1 ) {
        video_stream_id = i;
        // if we break, then we won't find the audio stream
        continue;
      } else {
        Warning( "Have another video stream." );
      }
    }
    if ( is_audio_stream( input_format_context->streams[i] ) ) {
      if ( audio_stream_id == -1 ) {
        audio_stream_id = i;
      } else {
        Warning( "Have another audio stream." );
      }
    }

#if LIBAVCODEC_VERSION_CHECK(57, 64, 0, 64, 0)
    streams[i].context = avcodec_alloc_context3( NULL );
    avcodec_parameters_to_context( streams[i].context, input_format_context->streams[i]->codecpar );
#else
    streams[i].context = input_format_context->streams[i]->codec;
#endif

    /** Find a decoder for the audio stream. */
    if (!(streams[i].codec = avcodec_find_decoder(input_format_context->streams[i]->codecpar->codec_id))) {
      Error( "Could not find input codec\n");
      avformat_close_input(&input_format_context);
      return AVERROR_EXIT;
    }

    /** Open the decoder for the audio stream to use it later. */
    if ((error = avcodec_open2( streams[i].context, streams[i].codec, NULL)) < 0) {
      Error( "Could not open input codec (error '%s')\n",
          av_make_error_string(error).c_str() );
      avcodec_free_context( &streams[i].context );
      avformat_close_input(&input_format_context);
      return error;
    }

  } // end foreach stream
  if ( video_stream_id == -1 )
    Error( "Unable to locate video stream in %s", filepath );
  if ( audio_stream_id == -1 )
    Debug( 3, "Unable to locate audio stream in %s", filepath );

  return 0;
} // end int FFmpeg::Open( const char * filepath )