Kevin Shanahan e11794d83e sound: don't cast away const pointers when not needed
Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
2012-12-02 14:22:13 +10:30

340 lines
7.2 KiB
C

/*
Copyright (C) 1996-1997 Id Software, Inc.
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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// snd_mem.c: sound caching
#include "common.h"
#include "console.h"
#include "quakedef.h"
#include "sound.h"
#include "sys.h"
typedef struct {
int rate;
int width;
int channels;
int loopstart;
int samples;
int dataofs; // chunk starts this many bytes from file start
} wavinfo_t;
static wavinfo_t *GetWavinfo(const char *name, const byte *wav, int wavlength);
/*
================
ResampleSfx
================
*/
static void
ResampleSfx(sfx_t *sfx, int inrate, int inwidth, const byte *data)
{
int outcount;
int srcsample;
float stepscale;
int i;
int sample, samplefrac, fracstep;
sfxcache_t *sc;
sc = Cache_Check(&sfx->cache);
if (!sc)
return;
stepscale = (float)inrate / shm->speed; // this is usually 0.5, 1, or 2
outcount = sc->length / stepscale;
sc->length = outcount;
if (sc->loopstart != -1)
sc->loopstart = sc->loopstart / stepscale;
sc->speed = shm->speed;
if (loadas8bit.value)
sc->width = 1;
else
sc->width = inwidth;
sc->stereo = 0;
// resample / decimate to the current source rate
if (stepscale == 1 && inwidth == 1 && sc->width == 1) {
// fast special case
for (i = 0; i < outcount; i++)
((signed char *)sc->data)[i]
= (int)((unsigned char)(data[i]) - 128);
} else {
// general case
samplefrac = 0;
fracstep = stepscale * 256;
for (i = 0; i < outcount; i++) {
srcsample = samplefrac >> 8;
samplefrac += fracstep;
if (inwidth == 2)
sample = LittleShort(((const short *)data)[srcsample]);
else
sample = (int)((unsigned char)(data[srcsample]) - 128) << 8;
if (sc->width == 2)
((short *)sc->data)[i] = sample;
else
((signed char *)sc->data)[i] = sample >> 8;
}
}
}
//=============================================================================
/*
==============
S_LoadSound
==============
*/
sfxcache_t *
S_LoadSound(sfx_t *s)
{
char namebuffer[256];
byte *data;
wavinfo_t *info;
int len;
float stepscale;
sfxcache_t *sc;
byte stackbuf[1024]; // avoid dirtying the cache heap
// see if still in memory
sc = Cache_Check(&s->cache);
if (sc)
return sc;
//Con_Printf ("S_LoadSound: %x\n", (int)stackbuf);
// load it in
strcpy(namebuffer, "sound/");
strcat(namebuffer, s->name);
// Con_Printf ("loading %s\n",namebuffer);
data = COM_LoadStackFile(namebuffer, stackbuf, sizeof(stackbuf), NULL);
if (!data) {
Con_Printf("Couldn't load %s\n", namebuffer);
return NULL;
}
info = GetWavinfo(s->name, data, com_filesize);
if (info->channels != 1) {
Con_Printf("%s is a stereo sample\n", s->name);
return NULL;
}
stepscale = (float)info->rate / shm->speed;
len = info->samples / stepscale;
len = len * info->width * info->channels;
sc = Cache_Alloc(&s->cache, len + sizeof(sfxcache_t), s->name);
if (!sc)
return NULL;
sc->length = info->samples;
sc->loopstart = info->loopstart;
sc->speed = info->rate;
sc->width = info->width;
sc->stereo = info->channels;
ResampleSfx(s, sc->speed, sc->width, data + info->dataofs);
return sc;
}
/*
===============================================================================
WAV loading
===============================================================================
*/
static const byte *data_p;
static const byte *iff_end;
static const byte *last_chunk;
static const byte *iff_data;
static int iff_chunk_len;
static short
GetLittleShort(void)
{
short val = 0;
val = *data_p;
val = val + (*(data_p + 1) << 8);
data_p += 2;
return val;
}
static int
GetLittleLong(void)
{
int val = 0;
val = *data_p;
val = val + (*(data_p + 1) << 8);
val = val + (*(data_p + 2) << 16);
val = val + (*(data_p + 3) << 24);
data_p += 4;
return val;
}
static void
FindNextChunk(const char *name, const char *filename)
{
while (1) {
/* Need at least 8 bytes for a chunk */
if (last_chunk + 8 >= iff_end) {
data_p = NULL;
return;
}
data_p = last_chunk + 4;
iff_chunk_len = GetLittleLong();
if (iff_chunk_len < 0 || iff_chunk_len > iff_end - data_p) {
Con_DPrintf("Bad \"%s\" chunk length (%d) in wav file %s\n",
name, iff_chunk_len, filename);
data_p = NULL;
return;
}
last_chunk = data_p + ((iff_chunk_len + 1) & ~1);
data_p -= 8;
if (!strncmp((const char *)data_p, name, 4))
return;
}
}
static void
FindChunk(const char *name, const char *filename)
{
last_chunk = iff_data;
FindNextChunk(name, filename);
}
#if 0
static void
DumpChunks(void)
{
char str[5];
str[4] = 0;
data_p = iff_data;
do {
memcpy(str, data_p, 4);
data_p += 4;
iff_chunk_len = GetLittleLong();
Con_Printf("0x%x : %s (%d)\n", (int)(data_p - 4), str, iff_chunk_len);
data_p += (iff_chunk_len + 1) & ~1;
} while (data_p < iff_end);
}
#endif
/*
============
GetWavinfo
============
*/
static wavinfo_t *
GetWavinfo(const char *name, const byte *wav, int wavlength)
{
static wavinfo_t info;
int i;
int format;
int samples;
memset(&info, 0, sizeof(info));
if (!wav)
return &info;
iff_data = wav;
iff_end = wav + wavlength;
// find "RIFF" chunk
FindChunk("RIFF", name);
if (!(data_p && !strncmp((char *)data_p + 8, "WAVE", 4))) {
Con_Printf("Missing RIFF/WAVE chunks\n");
return &info;
}
// get "fmt " chunk
iff_data = data_p + 12;
// DumpChunks ();
FindChunk("fmt ", name);
if (!data_p) {
Con_Printf("Missing fmt chunk\n");
return &info;
}
data_p += 8;
format = GetLittleShort();
if (format != 1) {
Con_Printf("Microsoft PCM format only\n");
return &info;
}
info.channels = GetLittleShort();
info.rate = GetLittleLong();
data_p += 4 + 2;
info.width = GetLittleShort() / 8;
// get cue chunk
FindChunk("cue ", name);
if (data_p) {
data_p += 32;
info.loopstart = GetLittleLong();
// if the next chunk is a LIST chunk, look for a cue length marker
FindNextChunk("LIST", name);
if (data_p) {
/* this is not a proper parse, but it works with cooledit... */
if (!strncmp((char *)data_p + 28, "mark", 4)) {
data_p += 24;
i = GetLittleLong(); // samples in loop
info.samples = info.loopstart + i;
}
}
} else
info.loopstart = -1;
// find data chunk
FindChunk("data", name);
if (!data_p) {
Con_Printf("Missing data chunk\n");
return &info;
}
data_p += 4;
samples = GetLittleLong() / info.width;
if (info.samples) {
if (samples < info.samples)
Sys_Error("Sound %s has a bad loop length", name);
} else
info.samples = samples;
info.dataofs = data_p - wav;
return &info;
}