ref: aa1286383efc26ee3bd558f5e12c64299931bdb4
parent: 10b519b13da20b264dc633e5af142a5aff447e10
author: Simon Howard <fraggle@gmail.com>
date: Sat Jan 7 11:26:50 EST 2006
Fix the behavior when expanding sound effects (again). Doom actually does play sounds of any sample rate, but the sound effects in Scientist 2 are corrupted. Add some tests to check that the sound effect header is correct, and generic sound rate conversion code. Subversion-branch: /trunk/chocolate-doom Subversion-revision: 257
--- a/src/i_sound.c
+++ b/src/i_sound.c
@@ -1,7 +1,7 @@
// Emacs style mode select -*- C++ -*-
//-----------------------------------------------------------------------------
//
-// $Id: i_sound.c 221 2005-10-23 18:39:45Z fraggle $
+// $Id: i_sound.c 257 2006-01-07 16:26:50Z fraggle $
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005 Simon Howard
@@ -22,6 +22,12 @@
// 02111-1307, USA.
//
// $Log$
+// Revision 1.23 2006/01/07 16:26:50 fraggle
+// Fix the behavior when expanding sound effects (again). Doom actually
+// does play sounds of any sample rate, but the sound effects in
+// Scientist 2 are corrupted. Add some tests to check that the sound
+// effect header is correct, and generic sound rate conversion code.
+//
// Revision 1.22 2005/10/23 18:39:45 fraggle
// Reproduce the behavior when playing a sound at a sample rate which
// is not 11025 or 22050Hz. This is to "fix" a bug in Scientist 2:
@@ -110,7 +116,7 @@
//-----------------------------------------------------------------------------
static const char
-rcsid[] = "$Id: i_sound.c 221 2005-10-23 18:39:45Z fraggle $";
+rcsid[] = "$Id: i_sound.c 257 2006-01-07 16:26:50Z fraggle $";
#include <stdio.h>
#include <stdlib.h>
@@ -174,10 +180,13 @@
Mix_Chunk *destination)
{byte *expanded = (byte *) destination->abuf;
+ int expanded_length;
int i;
if (samplerate == 11025)
{+ // Most of Doom's sound effects are 11025Hz
+
// need to expand to 2 channels, 11025->22050 and 8->16 bit
for (i=0; i<length; ++i)
@@ -206,6 +215,30 @@
expanded[i * 4 + 1] = expanded[i * 4 + 3] = (sample >> 8) & 0xff;
}
}
+ else
+ {+ // Generic expansion function for all other sample rates
+
+ // number of samples in the converted sound
+
+ expanded_length = (length * 22050) / samplerate;
+
+ for (i=0; i<expanded_length; ++i)
+ {+ Uint16 sample;
+ int src;
+
+ src = (i * length) / expanded_length;
+
+ sample = data[src] | (data[src] << 8);
+ sample -= 32768;
+
+ // expand 8->16 bits, mono->stereo
+
+ expanded[i * 4] = expanded[i * 4 + 2] = sample & 0xff;
+ expanded[i * 4 + 1] = expanded[i * 4 + 3] = (sample >> 8) & 0xff;
+ }
+ }
}
// Load and convert a sound effect
@@ -214,6 +247,7 @@
static boolean CacheSFX(int sound)
{int lumpnum;
+ int lumplen;
int samplerate;
int length;
int expanded_length;
@@ -223,21 +257,31 @@
lumpnum = I_GetSfxLumpNum(&S_sfx[sound]);
data = W_CacheLumpNum(lumpnum, PU_STATIC);
+ lumplen = W_LumpLength(lumpnum);
+ // Check the header, and ensure this is a valid sound
+
+ if (lumplen < 8
+ || data[0] != 0x03 || data[1] != 0x00
+ || data[6] != 0x00 || data[7] != 0x00)
+ {+ // Invalid sound
+
+ return false;
+ }
+
samplerate = (data[3] << 8) | data[2];
length = (data[5] << 8) | data[4];
- if (samplerate != 11025 && samplerate != 22050)
- {- // Sounds with unsupported sound rates are not played
- // in Vanilla Doom. As far as I know there are no other
- // supported sound sample rates apart from these two, but
- // it is possible there are others.
+ // If the header specifies that the length of the sound is greater than
+ // the length of the lump itself, this is an invalid sound lump
+ if (length - 8 > lumplen)
+ {return false;
}
- expanded_length = (length * 4) * (22050 / samplerate);
+ expanded_length = (length * 22050) / (samplerate / 4);
sound_chunks[sound].allocated = 1;
sound_chunks[sound].alen = expanded_length;