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/* aKode: Wav-Decoder
Copyright (C) 2004 Allan Sandfeld Jensen <kde@carewolf.com>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include <string.h>
#include "audioframe.h"
#include "decoder.h"
#include "file.h"
#include "wav_decoder.h"
#include <iostream>
namespace aKode {
bool WavDecoderPlugin::canDecode(File* src) {
char header[4];
bool res = false;
src->openRO();
if (src->read(header, 4) != 4 || memcmp(header, "RIFF",4) != 0 ) goto close;
src->seek(8);
if (src->read(header, 4) != 4 || memcmp(header, "WAVE",4) != 0 ) goto close;
src->seek(20);
if (src->read(header, 2) != 2 || memcmp(header, "\x01\0",2) != 0 ) goto close;
res = true;
close:
src->close();
return res;
}
extern "C" { WavDecoderPlugin wav_decoder; }
struct WavDecoder::private_data
{
private_data() : valid(false), buffer_length(0), buffer(0) {};
AudioConfiguration config;
bool valid;
long position;
long pos;
long length;
unsigned int buffer_length;
unsigned char *buffer;
File *src;
};
WavDecoder::WavDecoder(File *src) {
d = new private_data;
openFile(src);
}
bool WavDecoder::openFile(File* src) {
d->src = src;
src->openRO();
src->fadvise();
// Get format information
unsigned char buffer[4];
src->seek(4);
src->read((char*)buffer, 4); // size of stream
d->length = buffer[0] + buffer[1]*256 + buffer[2] * (1<<16) + buffer[3] * (1<<24) + 8;
src->seek(16);
src->read((char*)buffer, 4); // should really be 16
d->pos = 20 + buffer[0] + buffer[1]*256;
if (buffer[2] != 0 || buffer[3] != 0) goto invalid;
src->read((char*)buffer, 2); // check for compression
if (*(short*)buffer != 1) goto invalid;
src->read((char*)buffer, 2);
d->config.channels = buffer[0] + buffer[1]*256;
if (d->config.channels <=2)
d->config.channel_config = MonoStereo;
else
d->config.channel_config = MultiChannel;
src->read((char*)buffer, 4);
d->config.sample_rate = buffer[0] + buffer[1]*256 + buffer[2] * (1<<16) + buffer[3] * (1<<24);
src->seek(34);
src->read((char*)buffer, 2);
d->config.sample_width = buffer[0] + buffer[1]*256;
// Various sanity checks
if (d->config.sample_width != 8 && d->config.sample_width != 16 && d->config.sample_width != 32) goto invalid;
if (d->config.sample_rate > 200000) goto invalid;
find_data:
src->seek(d->pos);
src->read((char*)buffer, 4);
if (memcmp(buffer, "data", 4) != 0)
if (memcmp(buffer, "clm ", 4) != 0)
goto invalid;
else {
src->read((char*)buffer, 4);
d->pos = d->pos+ 8 + buffer[0] + buffer[1]*256;
goto find_data;
}
src->seek(d->pos+8); // start of data
d->position = 0;
d->valid = true;
// 1024 samples:
d->buffer_length = 1024*((d->config.sample_width+7)/8)*d->config.channels;
d->buffer = new unsigned char[d->buffer_length];
return true;
invalid:
std::cerr << "Invalid WAV file\n";
d->valid = false;
src->close();
return false;
}
void WavDecoder::close() {
d->src->close();
delete[] d->buffer;
d->valid = false;
}
WavDecoder::~WavDecoder() {
delete d;
}
bool WavDecoder::readFrame(AudioFrame* frame)
{
if (!d->valid || eof()) return false;
unsigned long samples = 1024;
// read a frame
unsigned long length;
length = d->src->read((char*)d->buffer, d->buffer_length);
if (length != d->buffer_length) {
samples = length / (d->config.channels * ((d->config.sample_width+7)/8));
}
d->pos += length;
d->position += samples;
// Ensure the frame is properly configured
frame->reserveSpace(&d->config, samples);
int channels = d->config.channels;
if (d->config.sample_width == 8) {
// WAV 8bit is unsigned
uint8_t* buffer = (uint8_t*)d->buffer;
int8_t** data = (int8_t**)frame->data;
for(unsigned int i=0; i<samples; i++)
for(int j=0; j<channels; j++)
data[j][i] = (int(buffer[i*channels+j])) - 128;
}
else
if (d->config.sample_width == 16) {
int16_t* buffer = (int16_t*)d->buffer;
int16_t** data = (int16_t**)frame->data;
for(unsigned int i=0; i<samples; i++)
for(int j=0; j<channels; j++)
data[j][i] = buffer[i*channels+j];
} else
if (d->config.sample_width == 32) {
int32_t* buffer = (int32_t*)d->buffer;
int32_t** data = (int32_t**)frame->data;
for(unsigned int i=0; i<samples; i++)
for(int j=0; j<channels; j++)
data[j][i] = buffer[i*channels+j];
} else
return false;
frame->pos = position();
return true;
}
long WavDecoder::length() {
if (!d->valid) return -1;
long byterate = d->config.sample_rate * d->config.channels * ((d->config.sample_width+7)/8);
return (d->length-44)/byterate;
}
long WavDecoder::position() {
if (!d->valid) return -1;
long div = (d->position / d->config.sample_rate) * 1000;
long rem = (d->position % d->config.sample_rate) * 1000;
return div + (rem / d->config.sample_rate);
}
bool WavDecoder::eof() {
if (!d->src) return true;
else return d->src->eof();
}
bool WavDecoder::error() {
return !d->valid;
}
bool WavDecoder::seek(long pos) {
int samplesize = d->config.channels * ((d->config.sample_width+7)/8);
long byterate = d->config.sample_rate * samplesize;
long sample_pos = (pos * byterate) / 1000;
long byte_pos = sample_pos * samplesize;
if (byte_pos+44 >= d->length) return false;
if (!d->src->seek(byte_pos+44)) return false;
d->pos = byte_pos + 44;
return true;
}
bool WavDecoder::seekable() {
return d->src->seekable();
}
const AudioConfiguration* WavDecoder::audioConfiguration() {
if (!d->valid) return 0;
return &d->config;
}
} // namespace
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