Aegisub/aegisub/src/audio_provider_stream.cpp

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// Copyright (c) 2006, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------------
//
// AEGISUB
//
// Website: http://aegisub.cellosoft.com
// Contact: mailto:zeratul@cellosoft.com
//
///////////
// Headers
#include "config.h"
#include "audio_provider_stream.h"
#include "utils.h"
#define BUFSIZE 65536
///////////////
// Constructor
StreamAudioProvider::StreamAudioProvider() {
bufLen = 8192;
startPos = 0;
endPos = BUFSIZE;
buffered = 0;
hasBuf = false;
num_samples = ~0ULL;
}
//////////////
// Destructor
StreamAudioProvider::~StreamAudioProvider() {
for (std::list<BufferChunk*>::iterator cur=buffer.begin();cur!=buffer.end();cur++) {
delete *cur;
}
buffer.clear();
}
/////////////
// Get audio
void StreamAudioProvider::GetAudio(void *buf, int64_t start, int64_t count) {
// Write
int64_t left = count;
int written = 0;
int toWrite;
short *dst = (short*) buf;
while (hasBuf && left > 0) {
// Discard done
if (startPos == BUFSIZE) {
delete buffer.front();
buffer.pop_front();
startPos = 0;
}
// Is last?
bool isLast = buffer.size() == 1;
int size = BUFSIZE;
if (isLast) size = endPos;
// Write
toWrite = MIN(size-startPos,int(left));
memcpy(dst+written,&(buffer.front()->buf[startPos]),toWrite*2);
startPos += toWrite;
written += toWrite;
left -= toWrite;
buffered -= toWrite;
// Last
if (isLast) break;
}
// Still left, fill with zero
if (left > 0) {
hasBuf = false;
for (int64_t i=written;i<count;i++) {
dst[i] = 0;
}
}
}
//////////////////////////
// Append audio to stream
void StreamAudioProvider::Append(void *voidptr, int64_t count) {
// Read
int64_t left = count;
int read = 0;
int toRead;
short *src = (short*) voidptr;
while (left > 0) {
// Check space
if (endPos == BUFSIZE) {
buffer.push_back(new BufferChunk);
endPos = 0;
}
// Read
toRead = MIN(int(BUFSIZE-endPos),int(left));
memcpy(&(buffer.back()->buf[endPos]),src+read,toRead*2);
endPos += toRead;
read += toRead;
buffered += toRead;
left -= toRead;
}
// Set buffered status
if (buffered > bufLen) hasBuf = true;
}
//////////////////
// Set parameters
void StreamAudioProvider::SetParams(int chan,int rate,int bps) {
channels = chan;
sample_rate = rate;
bytes_per_sample = bps;
}
////////////////////////////
// Buffer chunk constructor
StreamAudioProvider::BufferChunk::BufferChunk() {
buf.resize(BUFSIZE);
isFree = true;
}