void decodeFrame() throw(PacketDecodeException)
{
if (!hasPacket())
throw PacketDecodeException();
int dataSize = sampleBufferAlloc;
int used =
#if (LIBAVCODEC_VERSION_MAJOR >= 53)
avcodec_decode_audio3(
pCodecCtx,
(int16_t*)sampleBufferAligned, &dataSize,
&packet);
#else
avcodec_decode_audio2(
pCodecCtx,
(int16_t*)sampleBufferAligned, &dataSize,
packetBuffer, packetBufferSize);
#endif
if (used < 0)
throw PacketDecodeException();
#if (LIBAVCODEC_VERSION_MAJOR >= 53)
if ((size_t)used > packet.size)
used = packet.size;
(char*&)(packet.data) += used;
packet.size -= used;
#else
if ((size_t)used > packetBufferSize)
used = packetBufferSize;
(char*&)packetBuffer += used;
packetBufferSize -= used;
#endif
if (dataSize < 0)
dataSize = 0;
sampleBuffer = sampleBufferAligned;
sampleBufferStart += sampleBufferSize;
sampleBufferSize = dataSize / sampleSize;
if (sampleBufferStart + sampleBufferSize > streamSize)
streamSize = sampleBufferStart + sampleBufferSize;
}
/**
* A callback function that decodes a video packet. This should be supplied
* to the <code>decodePacketTemplate</code> template.
*
* @param codecContext - the codec context that will be used to decode the callback.
* @param packet - the packet that is to be decoded.
* @return the decoded packet as an AVFrame.
*/
static AVFrame* decodeVideoPacketCallBack(AVCodecContext *codecContext,
AVPacket *packet) {
if (AVMEDIA_TYPE_VIDEO != findCodecType(codecContext)) {
throw IllegalArgumentException(
"The supplied codec context for decodeVideoPacket(AVCodecContext*,AVPacket*) must have media type AVMEDIA_TYPE_VIDEO.");
}
AVFrame *decodedFrame = avcodec_alloc_frame();
int bytesDecoded = 0;
int frameDecoded = 0;
bytesDecoded = avcodec_decode_video2(codecContext, decodedFrame,
&frameDecoded,
packet);
if (AVERROR_INVALIDDATA == bytesDecoded) {
throw InvalidPacketDataException(errorMessage(bytesDecoded));
}
if (0 > bytesDecoded) {
throw PacketDecodeException(errorMessage(bytesDecoded));
}
if (0 != frameDecoded) return decodedFrame;
return NULL;
}
static AVPacket* encodeFrameWrapper(AVCodecContext *codecContext, const AVFrame *frame,
std::tr1::function<int(AVCodecContext *codecContext, AVPacket *packet,
const AVFrame *frame, int *packetEncoded)> encodeCallback) {
if (NULL == codecContext) {
throw IllegalArgumentException("The codec context for encoding cannot be null.");
}
if (NULL == frame) {
throw IllegalArgumentException("The frame for encoding cannot be null.");
}
AVPacket *packet = new AVPacket();
packet->size = 0;
packet->data = NULL;
av_init_packet(packet);
int packetEncoded = 0;
int result = encodeCallback(codecContext, packet, frame, &packetEncoded);
if (AVERROR_INVALIDDATA == result) {
throw InvalidPacketDataException(errorMessage(result));
}
if (0 > result) {
throw PacketDecodeException(errorMessage(result));
}
if (0 != packetEncoded) return packet;
return NULL;
}
/**
* A callback function that decodes an audio packet. This should be supplied
* to the <code>decodePacketTemplate</code> template.
*
* @param codecContext - the codec context that will be used to decode the callback.
* @param packet - the packet that is to be decoded.
* @return the decoded packet as a vector of AVFrames.
*/
static vector<AVFrame*> decodeAudioPacketCallback(AVCodecContext *codecContext,
AVPacket *packet) {
if (AVMEDIA_TYPE_AUDIO != findCodecType(codecContext)) {
throw IllegalArgumentException(
"The supplied codec context for decoding audio must have media type AVMEDIA_TYPE_AUDIO.");
}
// This vector will contain all the audio frames decoded from the supplied packet.
vector<AVFrame*> frames;
// The frame pointer that will hold each new frame before it is placed in the vector.
AVFrame *decodedFrame = NULL;
// This will be set to 1 if a frame has successfully been decoded with the
// avcodec_decode_audio4() function.
int frameDecoded = 0;
int bytesDecoded = 0; // The number of bytes that were decoded in each iteration.
while (0 < packet->size) {
// Create a new frame to contain the decoded data if one is required.
if (NULL == decodedFrame) decodedFrame = avcodec_alloc_frame();
// Decode the packet and store it in the new frame.
// Also record how many bytes were decoded because it might not have been all
// of them.
bytesDecoded = avcodec_decode_audio4(codecContext, decodedFrame,
&frameDecoded,
packet);
// If there is an invalid data error throw a more specific exception.
if (AVERROR_INVALIDDATA == bytesDecoded) {
throw InvalidPacketDataException(errorMessage(bytesDecoded));
}
if (0 > bytesDecoded) {
throw PacketDecodeException(errorMessage(bytesDecoded));
}
// If a frame was successfully decoded add it the vector to be returned and
// set the pointer to null to indicate we need a new frame allocated.
if (0 != frameDecoded) {
frames.push_back(decodedFrame);
decodedFrame = NULL;
} else {
// If we haven't successfully decoded a frame reset the decode frame
// values to make sure it's ready for another decode attempt.
avcodec_get_frame_defaults(decodedFrame);
}
// Push the data pointer down the byte array passed the last byte that we
// decoded.
packet->data += bytesDecoded;
// Reduce the relative size of the data to the amount that is yet to be
// decoded.
packet->size -= bytesDecoded;
}
return frames;
}
