Method ProcessAudioPacket

src/FFmpegReader.cpp:2078–2324

Process an audio packet

// Process an audio packet
void FFmpegReader::ProcessAudioPacket(int64_t requested_frame) {
	AudioLocation location;
	// Calculate location of current audio packet
	if (packet && packet->pts != AV_NOPTS_VALUE) {
		// Determine related video frame and starting sample # from audio PTS
		location = GetAudioPTSLocation(packet->pts);

		// Track 1st audio packet after a successful seek
		if (!seek_audio_frame_found && is_seeking)
			seek_audio_frame_found = location.frame;
	}

	// Create or get the existing frame object. Requested frame needs to be created
	// in working_cache at least once. Seek can clear the working_cache, so we must
	// add the requested frame back to the working_cache here. If it already exists,
	// it will be moved to the top of the working_cache.
	working_cache.Add(CreateFrame(requested_frame));

	// Debug output
	ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::ProcessAudioPacket (Before)",
										  "requested_frame", requested_frame,
										  "target_frame", location.frame,
										  "starting_sample", location.sample_start);

	// Init an AVFrame to hold the decoded audio samples
	int frame_finished = 0;
	AVFrame *audio_frame = AV_ALLOCATE_FRAME();
	AV_RESET_FRAME(audio_frame);

	int packet_samples = 0;
	int data_size = 0;

#if IS_FFMPEG_3_2
		int send_packet_err =  avcodec_send_packet(aCodecCtx, packet);
		if (send_packet_err < 0 && send_packet_err != AVERROR_EOF) {
			ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::ProcessAudioPacket (Packet not sent)");
		}
		else {
			int receive_frame_err = avcodec_receive_frame(aCodecCtx, audio_frame);
			if (receive_frame_err >= 0) {
				frame_finished = 1;
			}
			if (receive_frame_err == AVERROR_EOF) {
				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::ProcessAudioPacket (EOF detected from decoder)");
				packet_status.audio_eof = true;
			}
			if (receive_frame_err == AVERROR(EINVAL) || receive_frame_err == AVERROR_EOF) {
				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::ProcessAudioPacket (invalid frame received or EOF from decoder)");
				avcodec_flush_buffers(aCodecCtx);
			}
			if (receive_frame_err != 0) {
				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::ProcessAudioPacket (frame not ready yet from decoder)");
			}
		}
#else
		int used = avcodec_decode_audio4(aCodecCtx, audio_frame, &frame_finished, packet);
#endif