Merge pull request #14 from valnoel/fix_read_next_packet

cchampet · cchampet · commit 45650488d0c4 · 2014-12-03T19:20:12.000+01:00
Avoid a copy of packet data when readNextPacket
diff --git a/src/AvTranscoder/codedStream/AvInputStream.cpp b/src/AvTranscoder/codedStream/AvInputStream.cpp
@@ -72,43 +72,32 @@ bool AvInputStream::readNextPacket( CodedData& data )
 	if( ! _bufferized )
 		throw std::runtime_error( "Can't read packet on non-bufferized input stream." );
 
-	if( _streamCache.empty() )
-		_inputFile->readNextPacket( _streamIndex );
-
-	if( _streamCache.empty() )
-		return false;
-
-	_streamCache.front().getBuffer().swap( data.getBuffer() );
-
-	_streamCache.erase( _streamCache.begin() );
+	// if packet is already cached
+	if( ! _streamCache.empty() )
+	{
+		_streamCache.front().getBuffer().swap( data.getBuffer() );
+		_streamCache.erase( _streamCache.begin() );
+	}
+	// else read next packet
+	else
+	{
+		return _inputFile->readNextPacket( data, _streamIndex ) && _streamCache.empty();
+	}
 
 	return true;
 }
 
 void AvInputStream::addPacket( AVPacket& packet )
 {
-	//std::cout << "add packet for stream " << _streamIndex << std::endl;
-	CodedData data;
-	_streamCache.push_back( data );
-
+	// Do not cache data if the stream is declared as unused in process
 	if( ! _bufferized )
 		return;
 
-	// is it possible to remove this copy ?
-	// using : av_packet_unref ?
+	CodedData data;
+	_streamCache.push_back( data );
 	_streamCache.back().getBuffer().resize( packet.size );
 	if( packet.size != 0 )
 		memcpy( _streamCache.back().getPtr(), packet.data, packet.size );
-
-	// std::vector<unsigned char> tmpData( 0,0 );
-	// &tmpData[0] = packet.data;
-	// tmpData.size( packet.size );
-
-	// remove reference on packet because it's passed to CodedData
-	// packet.data = NULL;
-	// packet.size = 0;
-
-	// std::cout << this << " buffer size " << _streamCache.size() << std::endl;
 }
 
 VideoCodec& AvInputStream::getVideoCodec()
diff --git a/src/AvTranscoder/file/InputFile.cpp b/src/AvTranscoder/file/InputFile.cpp
@@ -144,7 +144,7 @@ AvInputStream& InputFile::getStream( size_t index )
 	return *_inputStreams.at( index );
 }
 
-bool InputFile::readNextPacket( const size_t streamIndex )
+bool InputFile::readNextPacket( CodedData& data, const size_t streamIndex )
 {
 	AVPacket packet;
 	av_init_packet( &packet );
@@ -157,15 +157,21 @@ bool InputFile::readNextPacket( const size_t streamIndex )
 			return false;
 		}
 
-		// send packet to stream buffer
-		_inputStreams.at( packet.stream_index )->addPacket( packet );
-
-		// We only read one stream and skip others
+		// if the packet stream is the expected one
+		// copy and return the packet data
 		if( packet.stream_index == (int)streamIndex )
 		{
+			data.getBuffer().resize( packet.size );
+			if( packet.size != 0 )
+				memcpy( data.getPtr(), packet.data, packet.size );
 			av_free_packet( &packet );
 			return true;
 		}
+		// else add the packet data to the stream cache
+		else
+		{
+			_inputStreams.at( packet.stream_index )->addPacket( packet );
+		}
 
 		// do not delete these 2 lines
 		// need to skip packet, delete this one and re-init for reading the next one
diff --git a/src/AvTranscoder/file/InputFile.hpp b/src/AvTranscoder/file/InputFile.hpp
@@ -86,16 +86,17 @@ class AvExport InputFile
 	AVFormatContext& getFormatContext() const { return *_formatContext; }
 
 	/**
-	 * @brief Read the next packet for the specified stream
-	 * @note For performances, each readed stream needs to be bufferized using the readStream() method.
-	 * @return if next packet was succefully readed
+	 * @brief Read the next packet of the specified stream
+	 * @param data: data of next packet read
+	 * @note For performances, each read stream needs to be bufferized using the readStream() method.
+	 * @return if next packet was succefully read
 	 **/
-	bool readNextPacket( const size_t streamIndex );
+	bool readNextPacket( CodedData& data, const size_t streamIndex );
 
 	/**
 	 * @brief Seek input stream at specified frame
 	 * @note clean also buffers in each InputStream
-	 * @return if next packet was succefully readed
+	 * @return if next packet was succefully read
 	 **/
 	void seekAtFrame( const size_t frame );
 
