ref: 5e956ae9355f38bafa811e97669f464ae2f8d3fe
dir: /snd_mem.c/
// snd_mem.c: sound caching
#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "quakedef.h"
int cache_full_cycle;
byte *S_Alloc (int size);
/*
================
ResampleSfx
================
*/
void ResampleSfx (sfx_t *sfx, int inrate, int inwidth, 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 ( ((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[1*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
Q_strcpy(namebuffer, "sound/");
Q_strcat(namebuffer, s->name);
// Con_Printf ("loading %s\n",namebuffer);
data = COM_LoadStackFile(namebuffer, stackbuf, sizeof(stackbuf));
if (!data)
{
Con_Printf ("Couldn't load %s\n", namebuffer);
return nil;
}
info = GetWavinfo (s->name, data, com_filesize);
if (info.channels != 1)
{
Con_Printf ("%s is a stereo sample\n",s->name);
return nil;
}
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 nil;
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
===============================================================================
*/
byte *data_p;
byte *iff_end;
byte *last_chunk;
byte *iff_data;
int iff_chunk_len;
short GetLittleShort(void)
{
short val;
val = *data_p;
val = val + (*(data_p+1)<<8);
data_p += 2;
return val;
}
int GetLittleLong(void)
{
int val;
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;
}
void FindNextChunk(char *name)
{
while (1)
{
data_p=last_chunk;
if (data_p >= iff_end)
{ // didn't find the chunk
data_p = nil;
return;
}
data_p += 4;
iff_chunk_len = GetLittleLong();
if (iff_chunk_len < 0)
{
data_p = nil;
return;
}
// if (iff_chunk_len > 1024*1024)
// Sys_Error ("FindNextChunk: %d length is past the 1 meg sanity limit", iff_chunk_len);
data_p -= 8;
last_chunk = data_p + 8 + ( (iff_chunk_len + 1) & ~1 );
if (!Q_strncmp((char *)data_p, name, 4))
return;
}
}
void FindChunk(char *name)
{
last_chunk = iff_data;
FindNextChunk (name);
}
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", (uintptr)(data_p - 4), str, iff_chunk_len);
data_p += (iff_chunk_len + 1) & ~1;
} while (data_p < iff_end);
}
/*
============
GetWavinfo
============
*/
wavinfo_t GetWavinfo (char *name, byte *wav, vlong wavlength)
{
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");
if (!(data_p && !Q_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 ");
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 ");
if (data_p)
{
data_p += 32;
info.loopstart = GetLittleLong();
// Con_Printf("loopstart=%d\n", sfx->loopstart);
// if the next chunk is a LIST chunk, look for a cue length marker
FindNextChunk ("LIST");
if (data_p)
{
if (!strncmp ((char *)data_p+28, "mark", 4))
{ // this is not a proper parse, but it works with cooledit...
data_p += 24;
i = GetLittleLong (); // samples in loop
info.samples = info.loopstart + i;
// Con_Printf("looped length: %d\n", i);
}
}
}
else
info.loopstart = -1;
// find data chunk
FindChunk("data");
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;
}