--- libgig/trunk/src/gig.cpp 2005/02/11 18:58:07 372 +++ libgig/trunk/src/gig.cpp 2005/02/17 02:22:26 384 @@ -2,8 +2,8 @@ * * * libgig - C++ cross-platform Gigasampler format file loader library * * * - * Copyright (C) 2003, 2004 by Christian Schoenebeck * - * * + * Copyright (C) 2003-2005 by Christian Schoenebeck * + * * * * * This library is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * @@ -23,6 +23,8 @@ #include "gig.h" +#include + namespace gig { namespace { // *************** Internal functions for sample decopmression *************** @@ -201,9 +203,8 @@ // *************** Sample *************** // * - unsigned int Sample::Instances = 0; - unsigned char* Sample::pDecompressionBuffer = NULL; - unsigned long Sample::DecompressionBufferSize = 0; + unsigned int Sample::Instances = 0; + buffer_t Sample::InternalDecompressionBuffer; Sample::Sample(File* pFile, RIFF::List* waveList, unsigned long WavePoolOffset) : DLS::Sample((DLS::File*) pFile, waveList, WavePoolOffset) { Instances++; @@ -244,9 +245,9 @@ } // we use a buffer for decompression and for truncating 24 bit samples to 16 bit - if ((Compressed || BitDepth == 24) && !pDecompressionBuffer) { - pDecompressionBuffer = new unsigned char[INITIAL_SAMPLE_BUFFER_SIZE]; - DecompressionBufferSize = INITIAL_SAMPLE_BUFFER_SIZE; + if ((Compressed || BitDepth == 24) && !InternalDecompressionBuffer.Size) { + InternalDecompressionBuffer.pStart = new unsigned char[INITIAL_SAMPLE_BUFFER_SIZE]; + InternalDecompressionBuffer.Size = INITIAL_SAMPLE_BUFFER_SIZE; } FrameOffset = 0; // just for streaming compressed samples @@ -260,7 +261,7 @@ std::list frameOffsets; SamplesPerFrame = BitDepth == 24 ? 256 : 2048; - WorstCaseFrameSize = SamplesPerFrame * FrameSize + Channels; + WorstCaseFrameSize = SamplesPerFrame * FrameSize + Channels; // +Channels for compression flag // Scanning pCkData->SetPos(0); @@ -341,9 +342,10 @@ * that will be returned to determine the actual cached samples, but note * that the size is given in bytes! You get the number of actually cached * samples by dividing it by the frame size of the sample: - * + * @code * buffer_t buf = pSample->LoadSampleData(acquired_samples); * long cachedsamples = buf.Size / pSample->FrameSize; + * @endcode * * @param SampleCount - number of sample points to load into RAM * @returns buffer_t structure with start address and size of @@ -389,10 +391,10 @@ * that will be returned to determine the actual cached samples, but note * that the size is given in bytes! You get the number of actually cached * samples by dividing it by the frame size of the sample: - * + * @code * buffer_t buf = pSample->LoadSampleDataWithNullSamplesExtension(acquired_samples, null_samples); * long cachedsamples = buf.Size / pSample->FrameSize; - * + * @endcode * The method will add \a NullSamplesCount silence samples past the * official buffer end (this won't affect the 'Size' member of the * buffer_t structure, that means 'Size' always reflects the size of the @@ -523,25 +525,29 @@ * for the next time you call this method is stored in \a pPlaybackState. * You have to allocate and initialize the playback_state_t structure by * yourself before you use it to stream a sample: - * - * - * gig::playback_state_t playbackstate;
- * playbackstate.position = 0;
- * playbackstate.reverse = false;
- * playbackstate.loop_cycles_left = pSample->LoopPlayCount;
- * - * + * @code + * gig::playback_state_t playbackstate; + * playbackstate.position = 0; + * playbackstate.reverse = false; + * playbackstate.loop_cycles_left = pSample->LoopPlayCount; + * @endcode * You don't have to take care of things like if there is actually a loop * defined or if the current read position is located within a loop area. * The method already handles such cases by itself. * + * Caution: If you are using more than one streaming thread, you + * have to use an external decompression buffer for EACH + * streaming thread to avoid race conditions and crashes! + * * @param pBuffer destination buffer * @param SampleCount number of sample points to read * @param pPlaybackState will be used to store and reload the playback * state for the next ReadAndLoop() call + * @param pExternalDecompressionBuffer (optional) external buffer to use for decompression * @returns number of successfully read sample points + * @see CreateDecompressionBuffer() */ - unsigned long Sample::ReadAndLoop(void* pBuffer, unsigned long SampleCount, playback_state_t* pPlaybackState) { + unsigned long Sample::ReadAndLoop(void* pBuffer, unsigned long SampleCount, playback_state_t* pPlaybackState, buffer_t* pExternalDecompressionBuffer) { unsigned long samplestoread = SampleCount, totalreadsamples = 0, readsamples, samplestoloopend; uint8_t* pDst = (uint8_t*) pBuffer; @@ -559,7 +565,7 @@ if (!pPlaybackState->reverse) { // forward playback do { samplestoloopend = this->LoopEnd - GetPos(); - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend)); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend), pExternalDecompressionBuffer); samplestoread -= readsamples; totalreadsamples += readsamples; if (readsamples == samplestoloopend) { @@ -585,7 +591,7 @@ // read samples for backward playback do { - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], samplestoreadinloop); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], samplestoreadinloop, pExternalDecompressionBuffer); samplestoreadinloop -= readsamples; samplestoread -= readsamples; totalreadsamples += readsamples; @@ -609,7 +615,7 @@ // forward playback (not entered the loop yet) if (!pPlaybackState->reverse) do { samplestoloopend = this->LoopEnd - GetPos(); - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend)); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend), pExternalDecompressionBuffer); samplestoread -= readsamples; totalreadsamples += readsamples; if (readsamples == samplestoloopend) { @@ -639,7 +645,7 @@ // if not endless loop check if max. number of loop cycles have been passed if (this->LoopPlayCount && !pPlaybackState->loop_cycles_left) break; samplestoloopend = this->LoopEnd - GetPos(); - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoreadinloop, samplestoloopend)); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoreadinloop, samplestoloopend), pExternalDecompressionBuffer); samplestoreadinloop -= readsamples; samplestoread -= readsamples; totalreadsamples += readsamples; @@ -661,7 +667,7 @@ // if not endless loop check if max. number of loop cycles have been passed if (this->LoopPlayCount && !pPlaybackState->loop_cycles_left) break; samplestoloopend = this->LoopEnd - GetPos(); - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend)); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], Min(samplestoread, samplestoloopend), pExternalDecompressionBuffer); samplestoread -= readsamples; totalreadsamples += readsamples; if (readsamples == samplestoloopend) { @@ -676,7 +682,7 @@ // read on without looping if (samplestoread) do { - readsamples = Read(&pDst[totalreadsamples * this->FrameSize], samplestoread); + readsamples = Read(&pDst[totalreadsamples * this->FrameSize], samplestoread, pExternalDecompressionBuffer); samplestoread -= readsamples; totalreadsamples += readsamples; } while (readsamples && samplestoread); @@ -695,17 +701,22 @@ * and SetPos() if you don't want to load the sample into RAM, * thus for disk streaming. * + * Caution: If you are using more than one streaming thread, you + * have to use an external decompression buffer for EACH + * streaming thread to avoid race conditions and crashes! + * * @param pBuffer destination buffer * @param SampleCount number of sample points to read + * @param pExternalDecompressionBuffer (optional) external buffer to use for decompression * @returns number of successfully read sample points - * @see SetPos() + * @see SetPos(), CreateDecompressionBuffer() */ - unsigned long Sample::Read(void* pBuffer, unsigned long SampleCount) { + unsigned long Sample::Read(void* pBuffer, unsigned long SampleCount, buffer_t* pExternalDecompressionBuffer) { if (SampleCount == 0) return 0; if (!Compressed) { if (BitDepth == 24) { // 24 bit sample. For now just truncate to 16 bit. - unsigned char* pSrc = this->pDecompressionBuffer; + unsigned char* pSrc = (unsigned char*) ((pExternalDecompressionBuffer) ? pExternalDecompressionBuffer->pStart : this->InternalDecompressionBuffer.pStart); int16_t* pDst = static_cast(pBuffer); if (Channels == 2) { // Stereo unsigned long readBytes = pCkData->Read(pSrc, SampleCount * 6, 1); @@ -742,14 +753,17 @@ currentframeoffset = this->FrameOffset; // offset in current sample frame since last Read() this->FrameOffset = 0; - if (assumedsize > this->DecompressionBufferSize) { - // local buffer reallocation - hope this won't happen - if (this->pDecompressionBuffer) delete[] this->pDecompressionBuffer; - this->pDecompressionBuffer = new unsigned char[assumedsize << 1]; // double of current needed size - this->DecompressionBufferSize = assumedsize << 1; + buffer_t* pDecompressionBuffer = (pExternalDecompressionBuffer) ? pExternalDecompressionBuffer : &InternalDecompressionBuffer; + + // if decompression buffer too small, then reduce amount of samples to read + if (pDecompressionBuffer->Size < assumedsize) { + std::cerr << "gig::Read(): WARNING - decompression buffer size too small!" << std::endl; + SampleCount = WorstCaseMaxSamples(pDecompressionBuffer); + remainingsamples = SampleCount; + assumedsize = GuessSize(SampleCount); } - unsigned char* pSrc = this->pDecompressionBuffer; + unsigned char* pSrc = (unsigned char*) pDecompressionBuffer->pStart; int16_t* pDst = static_cast(pBuffer); remainingbytes = pCkData->Read(pSrc, assumedsize, 1); @@ -870,8 +884,8 @@ assumedsize = GuessSize(remainingsamples); pCkData->SetPos(remainingbytes, RIFF::stream_backward); if (pCkData->RemainingBytes() < assumedsize) assumedsize = pCkData->RemainingBytes(); - remainingbytes = pCkData->Read(this->pDecompressionBuffer, assumedsize, 1); - pSrc = this->pDecompressionBuffer; + remainingbytes = pCkData->Read(pDecompressionBuffer->pStart, assumedsize, 1); + pSrc = (unsigned char*) pDecompressionBuffer->pStart; } } // while @@ -881,11 +895,54 @@ } } + /** + * Allocates a decompression buffer for streaming (compressed) samples + * with Sample::Read(). If you are using more than one streaming thread + * in your application you HAVE to create a decompression buffer + * for EACH of your streaming threads and provide it with the + * Sample::Read() call in order to avoid race conditions and crashes. + * + * You should free the memory occupied by the allocated buffer(s) once + * you don't need one of your streaming threads anymore by calling + * DestroyDecompressionBuffer(). + * + * @param MaxReadSize - the maximum size (in sample points) you ever + * expect to read with one Read() call + * @returns allocated decompression buffer + * @see DestroyDecompressionBuffer() + */ + buffer_t Sample::CreateDecompressionBuffer(unsigned long MaxReadSize) { + buffer_t result; + const double worstCaseHeaderOverhead = + (256.0 /*frame size*/ + 12.0 /*header*/ + 2.0 /*compression type flag (stereo)*/) / 256.0; + result.Size = (unsigned long) (double(MaxReadSize) * 3.0 /*(24 Bit)*/ * 2.0 /*stereo*/ * worstCaseHeaderOverhead); + result.pStart = new int8_t[result.Size]; + result.NullExtensionSize = 0; + return result; + } + + /** + * Free decompression buffer, previously created with + * CreateDecompressionBuffer(). + * + * @param DecompressionBuffer - previously allocated decompression + * buffer to free + */ + void Sample::DestroyDecompressionBuffer(buffer_t& DecompressionBuffer) { + if (DecompressionBuffer.Size && DecompressionBuffer.pStart) { + delete[] (int8_t*) DecompressionBuffer.pStart; + DecompressionBuffer.pStart = NULL; + DecompressionBuffer.Size = 0; + DecompressionBuffer.NullExtensionSize = 0; + } + } + Sample::~Sample() { Instances--; - if (!Instances && pDecompressionBuffer) { - delete[] pDecompressionBuffer; - pDecompressionBuffer = NULL; + if (!Instances && InternalDecompressionBuffer.Size) { + delete[] (unsigned char*) InternalDecompressionBuffer.pStart; + InternalDecompressionBuffer.pStart = NULL; + InternalDecompressionBuffer.Size = 0; } if (FrameTable) delete[] FrameTable; if (RAMCache.pStart) delete[] (int8_t*) RAMCache.pStart;