scummvm/backends/audiocd/linux/linux-audiocd.cpp
Donovan Watteau 7ef9247637 BACKENDS: Restore original Cabal license header when quoting it
Our derivate work remains GPLv3+, since the original allowed it thanks
to its GPLv2+ license, but when we quote the original license we can't
(and shouldn't) change the fact that it was GPLv2+.
2022-11-05 22:04:30 +01:00

473 lines
12 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/>.
*
* Original license header:
*
* Cabal - Legacy Game Implementations
*
* Cabal 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 2 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/>.
*
*/
// Enable all forbidden symbols to allow us to include and use necessary APIs.
#define FORBIDDEN_SYMBOL_ALLOW_ALL
#include "backends/audiocd/linux/linux-audiocd.h"
#ifdef USE_LINUXCD
#include "backends/audiocd/audiocd-stream.h"
#include "backends/audiocd/default/default-audiocd.h"
#include "common/array.h"
#include "common/config-manager.h"
#include "common/str.h"
#include "common/debug.h"
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/cdrom.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
enum {
kLeadoutTrack = 0xAA
};
enum {
kBytesPerFrame = 2352,
kSamplesPerFrame = kBytesPerFrame / 2
};
enum {
kSecondsPerMinute = 60,
kFramesPerSecond = 75
};
enum {
// Keep about a second's worth of audio in the buffer
kBufferThreshold = kFramesPerSecond
};
static int getFrameCount(const cdrom_msf0 &msf) {
int time = msf.minute;
time *= kSecondsPerMinute;
time += msf.second;
time *= kFramesPerSecond;
time += msf.frame;
return time;
}
// Helper function to convert an error code into a human-readable message
static Common::String getErrorMessage(int errorCode) {
char buf[256];
buf[0] = 0;
#ifdef _GNU_SOURCE
// glibc sucks
return Common::String(strerror_r(errorCode, buf, sizeof(buf)));
#else
strerror_r(errorCode, buf, sizeof(buf));
return Common::String(buf);
#endif
}
class LinuxAudioCDStream : public AudioCDStream {
public:
LinuxAudioCDStream(int fd, const cdrom_tocentry &startEntry, const cdrom_tocentry &endEntry);
~LinuxAudioCDStream();
protected:
uint getStartFrame() const;
uint getEndFrame() const;
bool readFrame(int frame, int16 *buffer);
private:
int _fd;
const cdrom_tocentry &_startEntry, &_endEntry;
};
LinuxAudioCDStream::LinuxAudioCDStream(int fd, const cdrom_tocentry &startEntry, const cdrom_tocentry &endEntry) :
_fd(fd), _startEntry(startEntry), _endEntry(endEntry) {
// We fill the buffer here already to prevent any out of sync issues due
// to the CD not yet having spun up.
startTimer(true);
}
LinuxAudioCDStream::~LinuxAudioCDStream() {
stopTimer();
}
bool LinuxAudioCDStream::readFrame(int frame, int16 *buffer) {
// Create the argument
union {
cdrom_msf msf;
char buffer[kBytesPerFrame];
} arg;
int seconds = frame / kFramesPerSecond;
frame %= kFramesPerSecond;
int minutes = seconds / kSecondsPerMinute;
seconds %= kSecondsPerMinute;
// Request to read that frame
// We don't use CDROMREADAUDIO, as it seems to cause kernel
// panics on ejecting discs. Probably bad to eject the disc
// while playing, but at least let's try to prevent that case.
arg.msf.cdmsf_min0 = minutes;
arg.msf.cdmsf_sec0 = seconds;
arg.msf.cdmsf_frame0 = frame;
// The "end" part is irrelevant (why isn't cdrom_msf0 the type
// instead?)
if (ioctl(_fd, CDROMREADRAW, &arg) < 0) {
warning("Failed to CD read audio: %s", getErrorMessage(errno).c_str());
return false;
}
memcpy(buffer, arg.buffer, kBytesPerFrame);
return true;
}
uint LinuxAudioCDStream::getStartFrame() const {
return getFrameCount(_startEntry.cdte_addr.msf);
}
uint LinuxAudioCDStream::getEndFrame() const {
return getFrameCount(_endEntry.cdte_addr.msf);
}
class LinuxAudioCDManager : public DefaultAudioCDManager {
public:
LinuxAudioCDManager();
~LinuxAudioCDManager();
bool open() override;
void close() override;
bool play(int track, int numLoops, int startFrame, int duration, bool onlyEmulate,
Audio::Mixer::SoundType soundType) override;
protected:
bool openCD(int drive) override;
bool openCD(const Common::String &drive) override;
private:
struct Device {
Device(const Common::String &n, dev_t d) : name(n), device(d) {}
Common::String name;
dev_t device;
};
typedef Common::Array<Device> DeviceList;
DeviceList scanDevices();
bool tryAddDrive(DeviceList &devices, const Common::String &drive);
bool tryAddDrive(DeviceList &devices, const Common::String &drive, dev_t device);
bool tryAddDrive(DeviceList &devices, dev_t device);
bool tryAddPath(DeviceList &devices, const Common::String &path);
bool tryAddGamePath(DeviceList &devices);
bool loadTOC();
static bool hasDevice(const DeviceList &devices, dev_t device);
int _fd;
cdrom_tochdr _tocHeader;
Common::Array<cdrom_tocentry> _tocEntries;
};
static bool isTrayEmpty(int errorNumber) {
switch (errorNumber) {
case EIO:
case ENOENT:
case EINVAL:
#ifdef ENOMEDIUM
case ENOMEDIUM:
#endif
return true;
}
return false;
}
LinuxAudioCDManager::LinuxAudioCDManager() {
_fd = -1;
memset(&_tocHeader, 0, sizeof(_tocHeader));
}
LinuxAudioCDManager::~LinuxAudioCDManager() {
close();
}
bool LinuxAudioCDManager::open() {
close();
if (openRealCD())
return true;
return DefaultAudioCDManager::open();
}
void LinuxAudioCDManager::close() {
DefaultAudioCDManager::close();
if (_fd < 0)
return;
::close(_fd);
memset(&_tocHeader, 0, sizeof(_tocHeader));
_tocEntries.clear();
}
bool LinuxAudioCDManager::openCD(int drive) {
DeviceList devices = scanDevices();
if (drive >= (int)devices.size())
return false;
_fd = ::open(devices[drive].name.c_str(), O_RDONLY | O_NONBLOCK, 0);
if (_fd < 0)
return false;
if (!loadTOC()) {
close();
return false;
}
return true;
}
bool LinuxAudioCDManager::openCD(const Common::String &drive) {
DeviceList devices;
if (!tryAddDrive(devices, drive) && !tryAddPath(devices, drive))
return false;
_fd = ::open(devices[0].name.c_str(), O_RDONLY | O_NONBLOCK, 0);
if (_fd < 0)
return false;
if (!loadTOC()) {
close();
return false;
}
return true;
}
bool LinuxAudioCDManager::play(int track, int numLoops, int startFrame, int duration, bool onlyEmulate,
Audio::Mixer::SoundType soundType) {
// Prefer emulation
if (DefaultAudioCDManager::play(track, numLoops, startFrame, duration, onlyEmulate, soundType))
return true;
// If we're set to only emulate, or have no CD drive, return here
if (onlyEmulate || _fd < 0)
return false;
// HACK: For now, just assume that track number is right
// That only works because ScummVM uses the wrong track number anyway
if (track >= (int)_tocEntries.size() - 1) {
warning("No such track %d", track);
return false;
}
// Bail if the track isn't an audio track
if ((_tocEntries[track].cdte_ctrl & 0x04) != 0) {
warning("Track %d is not audio", track);
return false;
}
// Create the AudioStream and play it
debug(1, "Playing CD track %d", track);
Audio::SeekableAudioStream *audioStream = new LinuxAudioCDStream(_fd, _tocEntries[track], _tocEntries[track + 1]);
Audio::Timestamp start = Audio::Timestamp(0, startFrame, 75);
Audio::Timestamp end = (duration == 0) ? audioStream->getLength() : Audio::Timestamp(0, startFrame + duration, 75);
// Fake emulation since we're really playing an AudioStream
_emulating = true;
_mixer->playStream(
soundType,
&_handle,
Audio::makeLoopingAudioStream(audioStream, start, end, (numLoops < 1) ? numLoops + 1 : numLoops),
-1,
_cd.volume,
_cd.balance,
DisposeAfterUse::YES,
true);
return true;
}
LinuxAudioCDManager::DeviceList LinuxAudioCDManager::scanDevices() {
DeviceList devices;
// Try to use the game's path first as the device
tryAddGamePath(devices);
// Try adding the default CD-ROM
tryAddDrive(devices, "/dev/cdrom");
// TODO: Try others?
return devices;
}
bool LinuxAudioCDManager::tryAddDrive(DeviceList &devices, const Common::String &drive) {
struct stat stbuf;
if (stat(drive.c_str(), &stbuf) < 0)
return false;
// Must be a character or block device
if (!S_ISCHR(stbuf.st_mode) && !S_ISBLK(stbuf.st_mode))
return false;
return tryAddDrive(devices, drive, stbuf.st_rdev);
}
bool LinuxAudioCDManager::tryAddDrive(DeviceList &devices, const Common::String &drive, dev_t device) {
if (hasDevice(devices, device))
return true;
// Try opening the device and seeing if it is a CD-ROM drve
int fd = ::open(drive.c_str(), O_RDONLY | O_NONBLOCK, 0);
if (fd >= 0) {
cdrom_subchnl info;
info.cdsc_format = CDROM_MSF;
bool isCD = ioctl(fd, CDROMSUBCHNL, &info) == 0 || isTrayEmpty(errno);
::close(fd);
if (isCD) {
devices.push_back(Device(drive, device));
return true;
}
}
return false;
}
bool LinuxAudioCDManager::tryAddDrive(DeviceList &devices, dev_t device) {
// Construct the block name
// TODO: libblkid's blkid_devno_to_devname is exactly what we look for.
// This requires an external dependency though.
Common::String name = Common::String::format("/dev/block/%d:%d", major(device), minor(device));
return tryAddDrive(devices, name, device);
}
bool LinuxAudioCDManager::tryAddPath(DeviceList &devices, const Common::String &path) {
struct stat stbuf;
if (stat(path.c_str(), &stbuf) < 0)
return false;
return tryAddDrive(devices, stbuf.st_dev);
}
bool LinuxAudioCDManager::tryAddGamePath(DeviceList &devices) {
if (!ConfMan.hasKey("path"))
return false;
return tryAddPath(devices, ConfMan.get("path"));
}
bool LinuxAudioCDManager::loadTOC() {
if (_fd < 0)
return false;
if (ioctl(_fd, CDROMREADTOCHDR, &_tocHeader) < 0)
return false;
debug(4, "CD: Start Track: %d, End Track %d", _tocHeader.cdth_trk0, _tocHeader.cdth_trk1);
for (int i = _tocHeader.cdth_trk0; i <= _tocHeader.cdth_trk1; i++) {
cdrom_tocentry entry;
memset(&entry, 0, sizeof(entry));
entry.cdte_track = i;
entry.cdte_format = CDROM_MSF;
if (ioctl(_fd, CDROMREADTOCENTRY, &entry) < 0)
return false;
#if 0
debug("Entry:");
debug("\tTrack: %d", entry.cdte_track);
debug("\tAdr: %d", entry.cdte_adr);
debug("\tCtrl: %d", entry.cdte_ctrl);
debug("\tFormat: %d", entry.cdte_format);
debug("\tMSF: %d:%d:%d", entry.cdte_addr.msf.minute, entry.cdte_addr.msf.second, entry.cdte_addr.msf.frame);
debug("\tMode: %d\n", entry.cdte_datamode);
#endif
_tocEntries.push_back(entry);
}
// Fetch the leadout so we can get the length of the last frame
cdrom_tocentry entry;
memset(&entry, 0, sizeof(entry));
entry.cdte_track = kLeadoutTrack;
entry.cdte_format = CDROM_MSF;
if (ioctl(_fd, CDROMREADTOCENTRY, &entry) < 0)
return false;
#if 0
debug("Lead out:");
debug("\tTrack: %d", entry.cdte_track);
debug("\tAdr: %d", entry.cdte_adr);
debug("\tCtrl: %d", entry.cdte_ctrl);
debug("\tFormat: %d", entry.cdte_format);
debug("\tMSF: %d:%d:%d", entry.cdte_addr.msf.minute, entry.cdte_addr.msf.second, entry.cdte_addr.msf.frame);
debug("\tMode: %d\n", entry.cdte_datamode);
#endif
_tocEntries.push_back(entry);
return true;
}
bool LinuxAudioCDManager::hasDevice(const DeviceList &devices, dev_t device) {
for (DeviceList::const_iterator it = devices.begin(); it != devices.end(); it++)
if (it->device == device)
return true;
return false;
}
AudioCDManager *createLinuxAudioCDManager() {
return new LinuxAudioCDManager();
}
#endif // USE_LINUXCD