Files
OpenSceneGraph/src/osgPlugins/ffmpeg/FFmpegDecoderAudio.cpp

305 lines
7.0 KiB
C++

#include "FFmpegDecoderAudio.hpp"
#include <osg/Notify>
#include <stdexcept>
#include <string.h>
//DEBUG
//#include <iostream>
namespace osgFFmpeg {
FFmpegDecoderAudio::FFmpegDecoderAudio(PacketQueue & packets, FFmpegClocks & clocks) :
m_packets(packets),
m_clocks(clocks),
m_stream(0),
m_context(0),
m_packet_data(0),
m_bytes_remaining(0),
m_audio_buffer((AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2),
m_audio_buf_size(0),
m_audio_buf_index(0),
m_end_of_stream(false),
m_exit(false)
{
}
FFmpegDecoderAudio::~FFmpegDecoderAudio()
{
if (isRunning())
{
m_exit = true;
join();
}
}
void FFmpegDecoderAudio::open(AVStream * const stream)
{
try
{
// Sound can be optional (i.e. no audio stream is present)
if (stream == 0)
return;
m_stream = stream;
m_context = stream->codec;
m_frequency = m_context->sample_rate;
m_nb_channels = m_context->channels;
m_sample_format = FFmpegSampleFormat(m_context->sample_fmt);
// Check stream sanity
if (m_context->codec_id == CODEC_ID_NONE)
throw std::runtime_error("invalid audio codec");;
// Find the decoder for the audio stream
AVCodec * const p_codec = avcodec_find_decoder(m_context->codec_id);
if (p_codec == 0)
throw std::runtime_error("avcodec_find_decoder() failed");
// Inform the codec that we can handle truncated bitstreams
//if (p_codec->capabilities & CODEC_CAP_TRUNCATED)
// m_context->flags |= CODEC_FLAG_TRUNCATED;
// Open codec
if (avcodec_open(m_context, p_codec) < 0)
throw std::runtime_error("avcodec_open() failed");
}
catch (...)
{
m_context = 0;
throw;
}
}
void FFmpegDecoderAudio::run()
{
try
{
decodeLoop();
}
catch (const std::exception & error)
{
osg::notify(osg::WARN) << "FFmpegDecoderAudio::run : " << error.what() << std::endl;
}
catch (...)
{
osg::notify(osg::WARN) << "FFmpegDecoderAudio::run : unhandled exception" << std::endl;
}
}
void FFmpegDecoderAudio::setAudioSink(osg::ref_ptr<osg::AudioSinkInterface> audio_sink)
{
// The FFmpegDecoderAudio object takes the responsability of destroying the audio_sink.
m_audio_sink = audio_sink;
}
void FFmpegDecoderAudio::fillBuffer(void * const buffer, size_t size)
{
size_t filled = 0;
uint8_t * dst_buffer = reinterpret_cast<uint8_t*>(buffer);
while (size != 0)
{
if (m_audio_buf_index == m_audio_buf_size)
{
m_audio_buf_index = 0;
// Pre-fetch audio buffer is empty, refill it.
const size_t bytes_decoded = decodeFrame(&m_audio_buffer[0], m_audio_buffer.size());
// If nothing could be decoded (e.g. error or no packet available), output a bit of silence
if (bytes_decoded == 0)
{
m_audio_buf_size = std::min(Buffer::size_type(1024), m_audio_buffer.size());
memset(&m_audio_buffer[0], 0, m_audio_buf_size);
}
else
{
m_audio_buf_size = bytes_decoded;
}
}
const size_t fill_size = std::min(m_audio_buf_size - m_audio_buf_index, size);
memcpy(dst_buffer, &m_audio_buffer[m_audio_buf_index], fill_size);
size -= fill_size;
dst_buffer += fill_size;
m_audio_buf_index += fill_size;
adjustBufferEndTps(fill_size);
}
}
void FFmpegDecoderAudio::decodeLoop()
{
const bool skip_audio = ! validContext() || ! m_audio_sink.valid();
if (! skip_audio && ! m_audio_sink->playing())
{
m_clocks.audioSetDelay(m_audio_sink->getDelay());
m_audio_sink->startPlaying();
}
else
{
m_clocks.audioDisable();
}
while (! m_exit)
{
// If skipping audio, make sure the audio stream is still consumed.
if (skip_audio)
{
bool is_empty;
FFmpegPacket packet = m_packets.timedPop(is_empty, 10);
if (packet.valid())
packet.clear();
}
// Else, just idle in this thread.
// Note: If m_audio_sink has an audio callback, this thread will still be awaken
// from time to time to refill the audio buffer.
else
{
OpenThreads::Thread::microSleep(10000);
}
}
}
void FFmpegDecoderAudio::adjustBufferEndTps(const size_t buffer_size)
{
int sample_size = nbChannels() * frequency();
switch (sampleFormat())
{
case SAMPLE_FORMAT_U8:
sample_size *= 1;
break;
case SAMPLE_FORMAT_S16:
sample_size *= 2;
break;
case SAMPLE_FORMAT_S24:
sample_size *= 3;
break;
case SAMPLE_FORMAT_S32:
sample_size *= 4;
break;
case SAMPLE_FORMAT_F32:
sample_size *= 4;
break;
default:
throw std::runtime_error("unsupported audio sample format");
}
m_clocks.audioAdjustBufferEndPts(double(buffer_size) / double(sample_size));
}
size_t FFmpegDecoderAudio::decodeFrame(void * const buffer, const size_t size)
{
for (;;)
{
// Decode current packet
while (m_bytes_remaining > 0)
{
int data_size = size;
const int bytes_decoded = avcodec_decode_audio2(m_context, reinterpret_cast<int16_t*>(buffer), &data_size, m_packet_data, m_bytes_remaining);
if (bytes_decoded < 0)
{
// if error, skip frame
m_bytes_remaining = 0;
break;
}
m_bytes_remaining -= bytes_decoded;
m_packet_data += bytes_decoded;
// If we have some data, return it and come back for more later.
if (data_size > 0)
return data_size;
}
// Get next packet
if (m_packet.valid())
m_packet.clear();
if (m_exit)
return 0;
bool is_empty = true;
m_packet = m_packets.tryPop(is_empty);
if (is_empty)
return 0;
if (m_packet.type == FFmpegPacket::PACKET_DATA)
{
if (m_packet.packet.pts != AV_NOPTS_VALUE)
{
const double pts = av_q2d(m_stream->time_base) * m_packet.packet.pts;
m_clocks.audioSetBufferEndPts(pts);
}
m_bytes_remaining = m_packet.packet.size;
m_packet_data = m_packet.packet.data;
}
else if (m_packet.type == FFmpegPacket::PACKET_END_OF_STREAM)
{
m_end_of_stream = true;
}
else if (m_packet.type == FFmpegPacket::PACKET_FLUSH)
{
avcodec_flush_buffers(m_context);
m_clocks.rewindAudio();
}
// just output silence when we reached the end of stream
if (m_end_of_stream)
{
memset(buffer, 0, size);
return size;
}
}
}
} // namespace osgFFmpeg