raze-gles/libraries/zmusic/decoder/mpg123_decoder.cpp

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2019-11-10 22:58:51 +00:00
/*
** mpg123_decoder.cpp
**
**---------------------------------------------------------------------------
** Copyright 2008-2010 Chris Robinson
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. 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.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
**---------------------------------------------------------------------------
**
*/
#include <algorithm>
#include <stdio.h>
#include "mpg123_decoder.h"
#include "i_module.h"
#ifdef HAVE_MPG123
FModule MPG123Module{"MPG123"};
#include "mpgload.h"
#ifdef _WIN32
#define MPG123LIB "libmpg123-0.dll"
#elif defined(__APPLE__)
#define MPG123LIB "libmpg123.0.dylib"
#else
#define MPG123LIB "libmpg123.so.0"
#endif
bool IsMPG123Present()
{
#if !defined DYN_MPG123
return true;
#else
static bool cached_result = false;
static bool done = false;
if (!done)
{
done = true;
auto abspath = module_progdir + "/" MPG123LIB;
cached_result = MPG123Module.Load({abspath.c_str(), MPG123LIB});
}
return cached_result;
#endif
}
static bool inited = false;
off_t MPG123Decoder::file_lseek(void *handle, off_t offset, int whence)
{
auto &reader = reinterpret_cast<MPG123Decoder*>(handle)->Reader;
if(whence == SEEK_CUR)
{
if(offset < 0 && reader->tell()+offset < 0)
return -1;
}
else if(whence == SEEK_END)
{
if(offset < 0 && reader->filelength() + offset < 0)
return -1;
}
if(reader->seek(offset, whence) != 0)
return -1;
return (off_t)reader->tell();
}
ssize_t MPG123Decoder::file_read(void *handle, void *buffer, size_t bytes)
{
auto &reader = reinterpret_cast<MPG123Decoder*>(handle)->Reader;
return (ssize_t)reader->read(buffer, (long)bytes);
}
MPG123Decoder::~MPG123Decoder()
{
if(MPG123)
{
mpg123_close(MPG123);
mpg123_delete(MPG123);
MPG123 = 0;
}
if (Reader) Reader->close();
Reader = nullptr;
}
bool MPG123Decoder::open(MusicIO::FileInterface *reader)
{
if(!inited)
{
if (!IsMPG123Present()) return false;
if(mpg123_init() != MPG123_OK) return false;
inited = true;
}
Reader = reader;
{
MPG123 = mpg123_new(NULL, NULL);
if(mpg123_replace_reader_handle(MPG123, file_read, file_lseek, NULL) == MPG123_OK &&
mpg123_open_handle(MPG123, this) == MPG123_OK)
{
int enc, channels;
long srate;
if(mpg123_getformat(MPG123, &srate, &channels, &enc) == MPG123_OK)
{
if((channels == 1 || channels == 2) && srate > 0 &&
mpg123_format_none(MPG123) == MPG123_OK &&
mpg123_format(MPG123, srate, channels, MPG123_ENC_SIGNED_16) == MPG123_OK)
{
// All OK
Done = false;
return true;
}
}
mpg123_close(MPG123);
}
mpg123_delete(MPG123);
MPG123 = 0;
}
Reader = nullptr; // need to give it back.
return false;
}
void MPG123Decoder::getInfo(int *samplerate, ChannelConfig *chans, SampleType *type)
{
int enc = 0, channels = 0;
long srate = 0;
mpg123_getformat(MPG123, &srate, &channels, &enc);
*samplerate = srate;
if(channels == 2)
*chans = ChannelConfig_Stereo;
else
*chans = ChannelConfig_Mono;
*type = SampleType_Int16;
}
size_t MPG123Decoder::read(char *buffer, size_t bytes)
{
size_t amt = 0;
while(!Done && bytes > 0)
{
size_t got = 0;
int ret = mpg123_read(MPG123, (unsigned char*)buffer, bytes, &got);
bytes -= got;
buffer += got;
amt += got;
if(ret == MPG123_NEW_FORMAT || ret == MPG123_DONE || got == 0)
{
Done = true;
break;
}
}
return amt;
}
bool MPG123Decoder::seek(size_t ms_offset, bool ms, bool mayrestart)
{
int enc, channels;
long srate;
if (!mayrestart || ms_offset > 0)
{
if (mpg123_getformat(MPG123, &srate, &channels, &enc) == MPG123_OK)
{
size_t smp_offset = ms ? (size_t)((double)ms_offset / 1000. * srate) : ms_offset;
if (mpg123_seek(MPG123, (off_t)smp_offset, SEEK_SET) >= 0)
{
Done = false;
return true;
}
}
return false;
}
else
{
// Restart the song instead of rewinding. A rewind seems to cause distortion when done repeatedly.
// offset is intentionally ignored here.
if (MPG123)
{
mpg123_close(MPG123);
mpg123_delete(MPG123);
MPG123 = 0;
}
Reader->seek(0, SEEK_SET);
// Do not call open with our own reader variable, that would be catastrophic.
auto reader = std::move(Reader);
return open(reader);
}
}
size_t MPG123Decoder::getSampleOffset()
{
return mpg123_tell(MPG123);
}
size_t MPG123Decoder::getSampleLength()
{
off_t len = mpg123_length(MPG123);
return (len > 0) ? len : 0;
}
#endif