Files
scummvm-cursorfix/engines/awe/aifc_player.cpp
2026-02-02 04:50:13 +01:00

140 lines
4.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "awe/aifc_player.h"
#include "awe/detection.h"
namespace Awe {
static uint32 READ_IEEE754(const uint8 *p) {
const uint32 m = READ_BE_UINT32(p + 2);
const int exp = 30 - p[1];
return (m >> exp);
}
AifcPlayer::AifcPlayer() {
}
bool AifcPlayer::play(int mixRate, const char *path, uint32 startOffset) {
_ssndSize = 0;
if (_f.open(path)) {
_f.seek(startOffset);
uint8 buf[12];
_f.read(buf, sizeof(buf));
if (memcmp(buf, "FORM", 4) == 0 && memcmp(buf + 8, "AIFC", 4) == 0) {
const uint32 size = READ_BE_UINT32(buf + 4);
for (uint32 offset = 12; offset + 8 < size; ) {
_f.seek(startOffset + offset);
_f.read(buf, 8);
const uint32 sz = READ_BE_UINT32(buf + 4);
if (memcmp(buf, "COMM", 4) == 0) {
const int channels = _f.readUint16BE();
_f.readUint32BE(); // samples per frame
const int bits = _f.readUint16BE();
_f.read(buf, 10);
const int rate = READ_IEEE754(buf);
if (channels != 2) {
warning("Unsupported AIFF-C channels %d rate %d (%s)", channels, rate, path);
break;
}
_f.read(buf, 4);
if (memcmp(buf, "SDX2", 4) != 0) {
warning("Unsupported compression");
break;
}
debugC(kDebugSound, "AIFF-C channels %d rate %d bits %d", channels, rate, bits);
_rate.reset(rate, mixRate);
} else if (memcmp(buf, "SSND", 4) == 0) {
_f.readUint32BE(); // block offset
_f.readUint32BE(); // block size
_ssndOffset = startOffset + offset + 8 + 8;
_ssndSize = sz;
debugC(kDebugSound, "AIFF-C ssnd size %d", _ssndSize);
break;
} else if (memcmp(buf, "FVER", 4) == 0) {
const uint32 version = _f.readUint32BE();
if (version != 0xA2805140) {
warning("Unexpected AIFF-C version 0x%x (%s)", version, path);
}
} else if (memcmp(buf, "INST", 4) == 0) {
// unused
} else if (memcmp(buf, "MARK", 4) == 0) {
const int count = _f.readUint16BE();
for (int i = 0; i < count; ++i) {
_f.readUint16BE(); // marker_id
_f.readUint32BE(); // marker_position
const int len = _f.readByte();
if (len != 0) {
char name[256];
_f.read(name, len);
name[len] = 0;
}
// pad ((len + 1) & 1)
}
} else {
warning("Unhandled AIFF-C tag '%02x%02x%02x%02x' size %d offset 0x%x path %s", buf[0], buf[1], buf[2], buf[3], sz, startOffset + offset, path);
break;
}
offset += sz + 8;
}
}
}
_pos = 0;
_sampleL = _sampleR = 0;
return _ssndSize != 0;
}
void AifcPlayer::stop() {
_f.close();
}
static int16 decodeSDX2(int16 prev, int8 data) {
const int sqr = data * ABS(data) * 2;
return (data & 1) != 0 ? prev + sqr : sqr;
}
int8 AifcPlayer::readSampleData() {
if (_pos >= _ssndSize) {
_pos = 0;
_f.seek(_ssndOffset);
}
const int8 data = _f.readByte();
++_pos;
return data;
}
void AifcPlayer::decodeSamples() {
for (const uint32 pos = _rate.getInt(); pos == _rate.getInt(); _rate.offset += _rate.inc) {
_sampleL = decodeSDX2(_sampleL, readSampleData());
_sampleR = decodeSDX2(_sampleR, readSampleData());
}
}
void AifcPlayer::readSamples(int16 *buf, int len) {
for (int i = 0; i < len; i += 2) {
decodeSamples();
*buf++ = _sampleL;
*buf++ = _sampleR;
}
}
} // namespace Awe