ref: 02fc812eff2d8e83887e3b149533e2ed3f95879f
dir: /src/i_sdlmusic.c/
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
// System interface for music.
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "SDL.h"
#include "SDL_mixer.h"
#include "i_midipipe.h"
#include "config.h"
#include "doomtype.h"
#include "memio.h"
#include "mus2mid.h"
#include "deh_str.h"
#include "gusconf.h"
#include "i_sound.h"
#include "i_system.h"
#include "i_swap.h"
#include "m_argv.h"
#include "m_config.h"
#include "m_misc.h"
#include "sha1.h"
#include "w_wad.h"
#include "z_zone.h"
#define MAXMIDLENGTH (96 * 1024)
#define MID_HEADER_MAGIC "MThd"
#define MUS_HEADER_MAGIC "MUS\x1a"
#define FLAC_HEADER "fLaC"
#define OGG_HEADER "OggS"
// Looping Vorbis metadata tag names. These have been defined by ZDoom
// for specifying the start and end positions for looping music tracks
// in .ogg and .flac files.
// More information is here: http://zdoom.org/wiki/Audio_loop
#define LOOP_START_TAG "LOOP_START"
#define LOOP_END_TAG "LOOP_END"
// FLAC metadata headers that we care about.
#define FLAC_STREAMINFO 0
#define FLAC_VORBIS_COMMENT 4
// Ogg metadata headers that we care about.
#define OGG_ID_HEADER 1
#define OGG_COMMENT_HEADER 3
// Structure for music substitution.
// We store a mapping based on SHA1 checksum -> filename of substitute music
// file to play, so that substitution occurs based on content rather than
// lump name. This has some inherent advantages:
// * Music for Plutonia (reused from Doom 1) works automatically.
// * If a PWAD replaces music, the replacement music is used rather than
// the substitute music for the IWAD.
// * If a PWAD reuses music from an IWAD (even from a different game), we get
// the high quality version of the music automatically (neat!)
typedef struct
{
sha1_digest_t hash;
char *filename;
} subst_music_t;
// Structure containing parsed metadata read from a digital music track:
typedef struct
{
boolean valid;
unsigned int samplerate_hz;
int start_time, end_time;
} file_metadata_t;
static subst_music_t *subst_music = NULL;
static unsigned int subst_music_len = 0;
static const char *subst_config_filenames[] =
{
"doom1-music.cfg",
"doom2-music.cfg",
"tnt-music.cfg",
"heretic-music.cfg",
"hexen-music.cfg",
"strife-music.cfg",
};
static boolean music_initialized = false;
// If this is true, this module initialized SDL sound and has the
// responsibility to shut it down
static boolean sdl_was_initialized = false;
static boolean musicpaused = false;
static int current_music_volume;
char *music_pack_path = "";
char *timidity_cfg_path = "";
static char *temp_timidity_cfg = NULL;
// If true, we are playing a substitute digital track rather than in-WAD
// MIDI/MUS track, and file_metadata contains loop metadata.
static boolean playing_substitute = false;
static file_metadata_t file_metadata;
// Position (in samples) that we have reached in the current track.
// This is updated by the TrackPositionCallback function.
static unsigned int current_track_pos;
// Currently playing music track.
static Mix_Music *current_track_music = NULL;
// If true, the currently playing track is being played on loop.
static boolean current_track_loop;
// Given a time string (for LOOP_START/LOOP_END), parse it and return
// the time (in # samples since start of track) it represents.
static unsigned int ParseVorbisTime(unsigned int samplerate_hz, char *value)
{
char *num_start, *p;
unsigned int result = 0;
char c;
if (strchr(value, ':') == NULL)
{
return atoi(value);
}
result = 0;
num_start = value;
for (p = value; *p != '\0'; ++p)
{
if (*p == '.' || *p == ':')
{
c = *p; *p = '\0';
result = result * 60 + atoi(num_start);
num_start = p + 1;
*p = c;
}
if (*p == '.')
{
return result * samplerate_hz
+ (unsigned int) (atof(p) * samplerate_hz);
}
}
return (result * 60 + atoi(num_start)) * samplerate_hz;
}
// Given a vorbis comment string (eg. "LOOP_START=12345"), set fields
// in the metadata structure as appropriate.
static void ParseVorbisComment(file_metadata_t *metadata, char *comment)
{
char *eq, *key, *value;
eq = strchr(comment, '=');
if (eq == NULL)
{
return;
}
key = comment;
*eq = '\0';
value = eq + 1;
if (!strcmp(key, LOOP_START_TAG))
{
metadata->start_time = ParseVorbisTime(metadata->samplerate_hz, value);
}
else if (!strcmp(key, LOOP_END_TAG))
{
metadata->end_time = ParseVorbisTime(metadata->samplerate_hz, value);
}
}
// Parse a vorbis comments structure, reading from the given file.
static void ParseVorbisComments(file_metadata_t *metadata, FILE *fs)
{
uint32_t buf;
unsigned int num_comments, i, comment_len;
char *comment;
// We must have read the sample rate already from an earlier header.
if (metadata->samplerate_hz == 0)
{
return;
}
// Skip the starting part we don't care about.
if (fread(&buf, 4, 1, fs) < 1)
{
return;
}
if (fseek(fs, LONG(buf), SEEK_CUR) != 0)
{
return;
}
// Read count field for number of comments.
if (fread(&buf, 4, 1, fs) < 1)
{
return;
}
num_comments = LONG(buf);
// Read each individual comment.
for (i = 0; i < num_comments; ++i)
{
// Read length of comment.
if (fread(&buf, 4, 1, fs) < 1)
{
return;
}
comment_len = LONG(buf);
// Read actual comment data into string buffer.
comment = calloc(1, comment_len + 1);
if (comment == NULL
|| fread(comment, 1, comment_len, fs) < comment_len)
{
free(comment);
break;
}
// Parse comment string.
ParseVorbisComment(metadata, comment);
free(comment);
}
}
static void ParseFlacStreaminfo(file_metadata_t *metadata, FILE *fs)
{
byte buf[34];
// Read block data.
if (fread(buf, sizeof(buf), 1, fs) < 1)
{
return;
}
// We only care about sample rate and song length.
metadata->samplerate_hz = (buf[10] << 12) | (buf[11] << 4)
| (buf[12] >> 4);
// Song length is actually a 36 bit field, but 32 bits should be
// enough for everybody.
//metadata->song_length = (buf[14] << 24) | (buf[15] << 16)
// | (buf[16] << 8) | buf[17];
}
static void ParseFlacFile(file_metadata_t *metadata, FILE *fs)
{
byte header[4];
unsigned int block_type;
size_t block_len;
boolean last_block;
for (;;)
{
long pos = -1;
// Read METADATA_BLOCK_HEADER:
if (fread(header, 4, 1, fs) < 1)
{
return;
}
block_type = header[0] & ~0x80;
last_block = (header[0] & 0x80) != 0;
block_len = (header[1] << 16) | (header[2] << 8) | header[3];
pos = ftell(fs);
if (pos < 0)
{
return;
}
if (block_type == FLAC_STREAMINFO)
{
ParseFlacStreaminfo(metadata, fs);
}
else if (block_type == FLAC_VORBIS_COMMENT)
{
ParseVorbisComments(metadata, fs);
}
if (last_block)
{
break;
}
// Seek to start of next block.
if (fseek(fs, pos + block_len, SEEK_SET) != 0)
{
return;
}
}
}
static void ParseOggIdHeader(file_metadata_t *metadata, FILE *fs)
{
byte buf[21];
if (fread(buf, sizeof(buf), 1, fs) < 1)
{
return;
}
metadata->samplerate_hz = (buf[8] << 24) | (buf[7] << 16)
| (buf[6] << 8) | buf[5];
}
static void ParseOggFile(file_metadata_t *metadata, FILE *fs)
{
byte buf[7];
unsigned int offset;
// Scan through the start of the file looking for headers. They
// begin '[byte]vorbis' where the byte value indicates header type.
memset(buf, 0, sizeof(buf));
for (offset = 0; offset < 100 * 1024; ++offset)
{
// buf[] is used as a sliding window. Each iteration, we
// move the buffer one byte to the left and read an extra
// byte onto the end.
memmove(buf, buf + 1, sizeof(buf) - 1);
if (fread(&buf[6], 1, 1, fs) < 1)
{
return;
}
if (!memcmp(buf + 1, "vorbis", 6))
{
switch (buf[0])
{
case OGG_ID_HEADER:
ParseOggIdHeader(metadata, fs);
break;
case OGG_COMMENT_HEADER:
ParseVorbisComments(metadata, fs);
break;
default:
break;
}
}
}
}
static void ReadLoopPoints(char *filename, file_metadata_t *metadata)
{
FILE *fs;
char header[4];
metadata->valid = false;
metadata->samplerate_hz = 0;
metadata->start_time = 0;
metadata->end_time = -1;
fs = fopen(filename, "rb");
if (fs == NULL)
{
return;
}
// Check for a recognized file format; use the first four bytes
// of the file.
if (fread(header, 4, 1, fs) < 1)
{
fclose(fs);
return;
}
if (memcmp(header, FLAC_HEADER, 4) == 0)
{
ParseFlacFile(metadata, fs);
}
else if (memcmp(header, OGG_HEADER, 4) == 0)
{
ParseOggFile(metadata, fs);
}
fclose(fs);
// Only valid if at the very least we read the sample rate.
metadata->valid = metadata->samplerate_hz > 0;
// If start and end time are both zero, ignore the loop tags.
// This is consistent with other source ports.
if (metadata->start_time == 0 && metadata->end_time == 0)
{
metadata->valid = false;
}
}
// Given a MUS lump, look up a substitute MUS file to play instead
// (or NULL to just use normal MIDI playback).
static char *GetSubstituteMusicFile(void *data, size_t data_len)
{
sha1_context_t context;
sha1_digest_t hash;
char *filename;
unsigned int i;
// Don't bother doing a hash if we're never going to find anything.
if (subst_music_len == 0)
{
return NULL;
}
SHA1_Init(&context);
SHA1_Update(&context, data, data_len);
SHA1_Final(hash, &context);
// Look for a hash that matches.
// The substitute mapping list can (intentionally) contain multiple
// filename mappings for the same hash. This allows us to try
// different files and fall back if our first choice isn't found.
filename = NULL;
for (i = 0; i < subst_music_len; ++i)
{
if (memcmp(hash, subst_music[i].hash, sizeof(hash)) == 0)
{
filename = subst_music[i].filename;
// If the file exists, then use this file in preference to
// any fallbacks. But we always return a filename if it's
// in the list, even if it's just so we can print an error
// message to the user saying it doesn't exist.
if (M_FileExists(filename))
{
break;
}
}
}
return filename;
}
// Add a substitute music file to the lookup list.
static void AddSubstituteMusic(subst_music_t *subst)
{
++subst_music_len;
subst_music =
I_Realloc(subst_music, sizeof(subst_music_t) * subst_music_len);
memcpy(&subst_music[subst_music_len - 1], subst, sizeof(subst_music_t));
}
static int ParseHexDigit(char c)
{
c = tolower(c);
if (c >= '0' && c <= '9')
{
return c - '0';
}
else if (c >= 'a' && c <= 'f')
{
return 10 + (c - 'a');
}
else
{
return -1;
}
}
static char *GetFullPath(char *base_filename, char *path)
{
char *basedir, *result;
// Starting with directory separator means we have an absolute path,
// so just return it.
if (path[0] == DIR_SEPARATOR)
{
return M_StringDuplicate(path);
}
#ifdef _WIN32
// d:\path\...
if (isalpha(path[0]) && path[1] == ':' && path[2] == DIR_SEPARATOR)
{
return M_StringDuplicate(path);
}
#endif
// Paths in the substitute filenames can contain Unix-style /
// path separators, but we should convert this to the separator
// for the native platform.
path = M_StringReplace(path, "/", DIR_SEPARATOR_S);
// Copy config filename and cut off the filename to just get the
// parent dir.
basedir = M_DirName(base_filename);
result = M_StringJoin(basedir, DIR_SEPARATOR_S, path, NULL);
free(basedir);
free(path);
return result;
}
// Parse a line from substitute music configuration file; returns error
// message or NULL for no error.
static char *ParseSubstituteLine(char *filename, char *line)
{
subst_music_t subst;
char *p;
int hash_index;
// Strip out comments if present.
p = strchr(line, '#');
if (p != NULL)
{
while (p > line && isspace(*(p - 1)))
{
--p;
}
*p = '\0';
}
// Skip leading spaces.
for (p = line; *p != '\0' && isspace(*p); ++p);
// Empty line? This includes comment lines now that comments have
// been stripped.
if (*p == '\0')
{
return NULL;
}
// Read hash.
hash_index = 0;
while (*p != '\0' && *p != '=' && !isspace(*p))
{
int d1, d2;
d1 = ParseHexDigit(p[0]);
d2 = ParseHexDigit(p[1]);
if (d1 < 0 || d2 < 0)
{
return "Invalid hex digit in SHA1 hash";
}
else if (hash_index >= sizeof(sha1_digest_t))
{
return "SHA1 hash too long";
}
subst.hash[hash_index] = (d1 << 4) | d2;
++hash_index;
p += 2;
}
if (hash_index != sizeof(sha1_digest_t))
{
return "SHA1 hash too short";
}
// Skip spaces.
for (; *p != '\0' && isspace(*p); ++p);
if (*p != '=')
{
return "Expected '='";
}
++p;
// Skip spaces.
for (; *p != '\0' && isspace(*p); ++p);
// We're now at the filename. Cut off trailing space characters.
while (strlen(p) > 0 && isspace(p[strlen(p) - 1]))
{
p[strlen(p) - 1] = '\0';
}
if (strlen(p) == 0)
{
return "No filename specified for music substitution";
}
// Expand full path and add to our database of substitutes.
subst.filename = GetFullPath(filename, p);
AddSubstituteMusic(&subst);
return NULL;
}
// Read a substitute music configuration file.
static boolean ReadSubstituteConfig(char *filename)
{
char *buffer;
char *line;
int linenum = 1;
// This unnecessarily opens the file twice...
if (!M_FileExists(filename))
{
return false;
}
M_ReadFile(filename, (byte **) &buffer);
line = buffer;
while (line != NULL)
{
char *error;
char *next;
// find end of line
char *eol = strchr(line, '\n');
if (eol != NULL)
{
// change the newline into NUL
*eol = '\0';
next = eol + 1;
}
else
{
// end of buffer
next = NULL;
}
error = ParseSubstituteLine(filename, line);
if (error != NULL)
{
fprintf(stderr, "%s:%i: Error: %s\n", filename, linenum, error);
}
++linenum;
line = next;
}
Z_Free(buffer);
return true;
}
// Find substitute configs and try to load them.
static void LoadSubstituteConfigs(void)
{
char *musicdir;
char *path;
unsigned int i;
// We can configure the path to music packs using the music_pack_path
// configuration variable. Otherwise we use the current directory, or
// $configdir/music to look for .cfg files.
if (strcmp(music_pack_path, "") != 0)
{
musicdir = M_StringJoin(music_pack_path, DIR_SEPARATOR_S, NULL);
}
else if (!strcmp(configdir, ""))
{
musicdir = M_StringDuplicate("");
}
else
{
musicdir = M_StringJoin(configdir, "music", DIR_SEPARATOR_S, NULL);
}
// Load all music packs. We always load all music substitution packs for
// all games. Why? Suppose we have a Doom PWAD that reuses some music from
// Heretic. If we have the Heretic music pack loaded, then we get an
// automatic substitution.
for (i = 0; i < arrlen(subst_config_filenames); ++i)
{
path = M_StringJoin(musicdir, subst_config_filenames[i], NULL);
ReadSubstituteConfig(path);
free(path);
}
free(musicdir);
if (subst_music_len > 0)
{
printf("Loaded %i music substitutions from config files.\n",
subst_music_len);
}
}
// Returns true if the given lump number is a music lump that should
// be included in substitute configs.
// Identifying music lumps by name is not feasible; some games (eg.
// Heretic, Hexen) don't have a common naming pattern for music lumps.
static boolean IsMusicLump(int lumpnum)
{
byte *data;
boolean result;
if (W_LumpLength(lumpnum) < 4)
{
return false;
}
data = W_CacheLumpNum(lumpnum, PU_STATIC);
result = memcmp(data, MUS_HEADER_MAGIC, 4) == 0
|| memcmp(data, MID_HEADER_MAGIC, 4) == 0;
W_ReleaseLumpNum(lumpnum);
return result;
}
// Dump an example config file containing checksums for all MIDI music
// found in the WAD directory.
static void DumpSubstituteConfig(char *filename)
{
sha1_context_t context;
sha1_digest_t digest;
char name[9];
byte *data;
FILE *fs;
unsigned int lumpnum;
size_t h;
fs = fopen(filename, "w");
if (fs == NULL)
{
I_Error("Failed to open %s for writing", filename);
return;
}
fprintf(fs, "# Example %s substitute MIDI file.\n\n", PACKAGE_NAME);
fprintf(fs, "# SHA1 hash = filename\n");
for (lumpnum = 0; lumpnum < numlumps; ++lumpnum)
{
strncpy(name, lumpinfo[lumpnum]->name, 8);
name[8] = '\0';
if (!IsMusicLump(lumpnum))
{
continue;
}
// Calculate hash.
data = W_CacheLumpNum(lumpnum, PU_STATIC);
SHA1_Init(&context);
SHA1_Update(&context, data, W_LumpLength(lumpnum));
SHA1_Final(digest, &context);
W_ReleaseLumpNum(lumpnum);
// Print line.
for (h = 0; h < sizeof(sha1_digest_t); ++h)
{
fprintf(fs, "%02x", digest[h]);
}
fprintf(fs, " = %s.ogg\n", name);
}
fprintf(fs, "\n");
fclose(fs);
printf("Substitute MIDI config file written to %s.\n", filename);
I_Quit();
}
// If the temp_timidity_cfg config variable is set, generate a "wrapper"
// config file for Timidity to point to the actual config file. This
// is needed to inject a "dir" command so that the patches are read
// relative to the actual config file.
static boolean WriteWrapperTimidityConfig(char *write_path)
{
char *path;
FILE *fstream;
if (!strcmp(timidity_cfg_path, ""))
{
return false;
}
fstream = fopen(write_path, "w");
if (fstream == NULL)
{
return false;
}
path = M_DirName(timidity_cfg_path);
fprintf(fstream, "dir %s\n", path);
free(path);
fprintf(fstream, "source %s\n", timidity_cfg_path);
fclose(fstream);
return true;
}
void I_InitTimidityConfig(void)
{
char *env_string;
boolean success;
temp_timidity_cfg = M_TempFile("timidity.cfg");
if (snd_musicdevice == SNDDEVICE_GUS)
{
success = GUS_WriteConfig(temp_timidity_cfg);
}
else
{
success = WriteWrapperTimidityConfig(temp_timidity_cfg);
}
// Set the TIMIDITY_CFG environment variable to point to the temporary
// config file.
if (success)
{
env_string = M_StringJoin("TIMIDITY_CFG=", temp_timidity_cfg, NULL);
putenv(env_string);
}
else
{
free(temp_timidity_cfg);
temp_timidity_cfg = NULL;
}
}
// Remove the temporary config file generated by I_InitTimidityConfig().
static void RemoveTimidityConfig(void)
{
if (temp_timidity_cfg != NULL)
{
remove(temp_timidity_cfg);
free(temp_timidity_cfg);
}
}
// Shutdown music
static void I_SDL_ShutdownMusic(void)
{
if (music_initialized)
{
#if defined(_WIN32)
I_MidiPipe_ShutdownServer();
#endif
Mix_HaltMusic();
music_initialized = false;
if (sdl_was_initialized)
{
Mix_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
sdl_was_initialized = false;
}
}
}
static boolean SDLIsInitialized(void)
{
int freq, channels;
Uint16 format;
return Mix_QuerySpec(&freq, &format, &channels) != 0;
}
// Callback function that is invoked to track current track position.
void TrackPositionCallback(int chan, void *stream, int len, void *udata)
{
// Position is doubled up twice: for 16-bit samples and for stereo.
current_track_pos += len / 4;
}
// Initialize music subsystem
static boolean I_SDL_InitMusic(void)
{
int i;
//!
// @category obscure
// @arg <filename>
//
// Read all MIDI files from loaded WAD files, dump an example substitution
// music config file to the specified filename and quit.
//
i = M_CheckParmWithArgs("-dumpsubstconfig", 1);
if (i > 0)
{
DumpSubstituteConfig(myargv[i + 1]);
}
// If SDL_mixer is not initialized, we have to initialize it
// and have the responsibility to shut it down later on.
if (SDLIsInitialized())
{
music_initialized = true;
}
else
{
if (SDL_Init(SDL_INIT_AUDIO) < 0)
{
fprintf(stderr, "Unable to set up sound.\n");
}
else if (Mix_OpenAudio(snd_samplerate, AUDIO_S16SYS, 2, 1024) < 0)
{
fprintf(stderr, "Error initializing SDL_mixer: %s\n",
Mix_GetError());
SDL_QuitSubSystem(SDL_INIT_AUDIO);
}
else
{
SDL_PauseAudio(0);
sdl_was_initialized = true;
music_initialized = true;
}
}
// Once initialization is complete, the temporary Timidity config
// file can be removed.
RemoveTimidityConfig();
// If snd_musiccmd is set, we need to call Mix_SetMusicCMD to
// configure an external music playback program.
if (strlen(snd_musiccmd) > 0)
{
Mix_SetMusicCMD(snd_musiccmd);
}
// Register an effect function to track the music position.
Mix_RegisterEffect(MIX_CHANNEL_POST, TrackPositionCallback, NULL, NULL);
// If we're in GENMIDI mode, try to load sound packs.
if (snd_musicdevice == SNDDEVICE_GENMIDI)
{
LoadSubstituteConfigs();
}
#if defined(_WIN32)
// [AM] Start up midiproc to handle playing MIDI music.
I_MidiPipe_InitServer();
#endif
return music_initialized;
}
//
// SDL_mixer's native MIDI music playing does not pause properly.
// As a workaround, set the volume to 0 when paused.
//
static void UpdateMusicVolume(void)
{
int vol;
if (musicpaused)
{
vol = 0;
}
else
{
vol = (current_music_volume * MIX_MAX_VOLUME) / 127;
}
#if defined(_WIN32)
I_MidiPipe_SetVolume(vol);
#endif
Mix_VolumeMusic(vol);
}
// Set music volume (0 - 127)
static void I_SDL_SetMusicVolume(int volume)
{
// Internal state variable.
current_music_volume = volume;
UpdateMusicVolume();
}
// Start playing a mid
static void I_SDL_PlaySong(void *handle, boolean looping)
{
int loops;
if (!music_initialized)
{
return;
}
if (handle == NULL && !midi_server_registered)
{
return;
}
current_track_music = (Mix_Music *) handle;
current_track_loop = looping;
if (looping)
{
loops = -1;
}
else
{
loops = 1;
}
// Don't loop when playing substitute music, as we do it
// ourselves instead.
if (playing_substitute && file_metadata.valid)
{
loops = 1;
SDL_LockAudio();
current_track_pos = 0; // start of track
SDL_UnlockAudio();
}
#if defined(_WIN32)
if (midi_server_registered)
{
I_MidiPipe_PlaySong(loops);
}
else
#endif
{
Mix_PlayMusic(current_track_music, loops);
}
}
static void I_SDL_PauseSong(void)
{
if (!music_initialized)
{
return;
}
musicpaused = true;
UpdateMusicVolume();
}
static void I_SDL_ResumeSong(void)
{
if (!music_initialized)
{
return;
}
musicpaused = false;
UpdateMusicVolume();
}
static void I_SDL_StopSong(void)
{
if (!music_initialized)
{
return;
}
#if defined(_WIN32)
if (midi_server_registered)
{
I_MidiPipe_StopSong();
}
else
#endif
{
Mix_HaltMusic();
}
playing_substitute = false;
current_track_music = NULL;
}
static void I_SDL_UnRegisterSong(void *handle)
{
Mix_Music *music = (Mix_Music *) handle;
if (!music_initialized)
{
return;
}
if (handle == NULL)
{
return;
}
Mix_FreeMusic(music);
}
// Determine whether memory block is a .mid file
static boolean IsMid(byte *mem, int len)
{
return len > 4 && !memcmp(mem, "MThd", 4);
}
static boolean ConvertMus(byte *musdata, int len, char *filename)
{
MEMFILE *instream;
MEMFILE *outstream;
void *outbuf;
size_t outbuf_len;
int result;
instream = mem_fopen_read(musdata, len);
outstream = mem_fopen_write();
result = mus2mid(instream, outstream);
if (result == 0)
{
mem_get_buf(outstream, &outbuf, &outbuf_len);
M_WriteFile(filename, outbuf, outbuf_len);
}
mem_fclose(instream);
mem_fclose(outstream);
return result;
}
static void *I_SDL_RegisterSong(void *data, int len)
{
char *filename;
Mix_Music *music;
if (!music_initialized)
{
return NULL;
}
playing_substitute = false;
// See if we're substituting this MUS for a high-quality replacement.
filename = GetSubstituteMusicFile(data, len);
if (filename != NULL)
{
music = Mix_LoadMUS(filename);
if (music == NULL)
{
// Fall through and play MIDI normally, but print an error
// message.
fprintf(stderr, "Failed to load substitute music file: %s: %s\n",
filename, Mix_GetError());
}
else
{
// Read loop point metadata from the file so that we know where
// to loop the music.
playing_substitute = true;
ReadLoopPoints(filename, &file_metadata);
return music;
}
}
// MUS files begin with "MUS"
// Reject anything which doesnt have this signature
filename = M_TempFile("doom.mid");
if (IsMid(data, len) && len < MAXMIDLENGTH)
{
M_WriteFile(filename, data, len);
}
else
{
// Assume a MUS file and try to convert
ConvertMus(data, len, filename);
}
// Load the MIDI. In an ideal world we'd be using Mix_LoadMUS_RW()
// by now, but Mix_SetMusicCMD() only works with Mix_LoadMUS(), so
// we have to generate a temporary file.
#if defined(_WIN32)
// [AM] If we do not have an external music command defined, play
// music with the MIDI server.
if (midi_server_initialized)
{
music = NULL;
if (!I_MidiPipe_RegisterSong(filename))
{
fprintf(stderr, "Error loading midi: %s\n",
"Could not communicate with midiproc.");
}
}
else
#endif
{
music = Mix_LoadMUS(filename);
if (music == NULL)
{
// Failed to load
fprintf(stderr, "Error loading midi: %s\n", Mix_GetError());
}
// Remove the temporary MIDI file; however, when using an external
// MIDI program we can't delete the file. Otherwise, the program
// won't find the file to play. This means we leave a mess on
// disk :(
if (strlen(snd_musiccmd) == 0)
{
remove(filename);
}
}
free(filename);
return music;
}
// Is the song playing?
static boolean I_SDL_MusicIsPlaying(void)
{
if (!music_initialized)
{
return false;
}
return Mix_PlayingMusic();
}
// Get position in substitute music track, in seconds since start of track.
static double GetMusicPosition(void)
{
unsigned int music_pos;
int freq;
Mix_QuerySpec(&freq, NULL, NULL);
SDL_LockAudio();
music_pos = current_track_pos;
SDL_UnlockAudio();
return (double) music_pos / freq;
}
static void RestartCurrentTrack(void)
{
double start = (double) file_metadata.start_time
/ file_metadata.samplerate_hz;
// If the track finished we need to restart it.
if (current_track_music != NULL)
{
Mix_PlayMusic(current_track_music, 1);
}
Mix_SetMusicPosition(start);
SDL_LockAudio();
current_track_pos = file_metadata.start_time;
SDL_UnlockAudio();
}
// Poll music position; if we have passed the loop point end position
// then we need to go back.
static void I_SDL_PollMusic(void)
{
// When playing substitute tracks, loop tags only apply if we're playing
// a looping track. Tracks like the title screen music have the loop
// tags ignored.
if (current_track_loop && playing_substitute && file_metadata.valid)
{
double end = (double) file_metadata.end_time
/ file_metadata.samplerate_hz;
// If we have reached the loop end point then we have to take action.
if (file_metadata.end_time >= 0 && GetMusicPosition() >= end)
{
RestartCurrentTrack();
}
// Have we reached the actual end of track (not loop end)?
if (!Mix_PlayingMusic())
{
RestartCurrentTrack();
}
}
}
static snddevice_t music_sdl_devices[] =
{
SNDDEVICE_PAS,
SNDDEVICE_GUS,
SNDDEVICE_WAVEBLASTER,
SNDDEVICE_SOUNDCANVAS,
SNDDEVICE_GENMIDI,
SNDDEVICE_AWE32,
};
music_module_t music_sdl_module =
{
music_sdl_devices,
arrlen(music_sdl_devices),
I_SDL_InitMusic,
I_SDL_ShutdownMusic,
I_SDL_SetMusicVolume,
I_SDL_PauseSong,
I_SDL_ResumeSong,
I_SDL_RegisterSong,
I_SDL_UnRegisterSong,
I_SDL_PlaySong,
I_SDL_StopSong,
I_SDL_MusicIsPlaying,
I_SDL_PollMusic,
};