[SDL] VOC file support for SDL_mixer.

Ryan C. Gordon icculus at linuxgames.com
Tue Jun 5 11:01:51 PDT 2001


Attached is a patch against the latest CVS of SDL_mixer which adds
Creative Labs VOC file support.

I've tested it briefly by passing some of the VOCs from Duke Nukem 3D
through playwave and everything seems to work well enough.

Comments, criticism and patches are, of course, welcome.

--ryan. (icculus at linuxgames.com)


-------------- next part --------------
diff -urBbN --exclude=*CVS* SDL_mixer-virgin/Makefile.am SDL_mixer/Makefile.am
--- SDL_mixer-virgin/Makefile.am	Sat Apr 28 13:01:50 2001
+++ SDL_mixer/Makefile.am	Tue Jun  5 08:31:25 2001
@@ -9,6 +9,10 @@
 libSDL_mixerinclude_HEADERS =	\
 	SDL_mixer.h
 
+if VOC_SAMPLES
+VOC_SRC = voc.c
+endif
+
 libSDL_mixer_la_SOURCES =	\
 	mixer.c			\
 	music.c			\
@@ -18,7 +22,9 @@
 	music_ogg.h		\
 	wave.h			\
 	wavestream.c		\
-	wavestream.h
+	wavestream.h    \
+    $(VOC_SRC)
+
 
 if USE_MIKMOD
 MIKMOD_LIB = mikmod/libmikmod.la
diff -urBbN --exclude=*CVS* SDL_mixer-virgin/README SDL_mixer/README
--- SDL_mixer-virgin/README	Thu Apr  5 20:27:03 2001
+++ SDL_mixer/README	Tue Jun  5 09:18:49 2001
@@ -12,10 +12,10 @@
 See the header file SDL_mixer.h and the examples playwave.c and playmus.c
 for documentation on this mixer library.
 
-The mixer can currently load Microsoft WAVE files as audio samples
-and can load MIDI files via Timidity and the following music formats
-via MikMod:  .MOD .S3M .IT .XM. It can also load MP3 music using the
-SMPEG library.
+The mixer can currently load Microsoft WAVE files and Creative Labs VOC
+files as audio samples, and can load MIDI files via Timidity and the
+following music formats via MikMod:  .MOD .S3M .IT .XM. It can also load
+MP3 music using the SMPEG library.
 
 The process of mixing MIDI files to wave output is very CPU intensive,
 so if playing regular WAVE files sound great, but playing MIDI files
diff -urBbN --exclude=*CVS* SDL_mixer-virgin/configure.in SDL_mixer/configure.in
--- SDL_mixer-virgin/configure.in	Sat Apr 28 13:01:50 2001
+++ SDL_mixer/configure.in	Tue Jun  5 08:34:52 2001
@@ -80,6 +80,15 @@
 CFLAGS="$CFLAGS -DUSE_RWOPS"
 
 dnl Check command-line options
+
+dnl rcg06052001 VOC file support by Ryan C. Gordon (icculus at linuxgames.com).
+AC_ARG_ENABLE(samples-voc,
+[  --enable-samples-voc    enable support for VOC samples [default=yes]],
+              , enable_samples_voc=yes)
+if test x$enable_samples_voc = xyes; then
+    CFLAGS="$CFLAGS -DVOC_SAMPLES"
+fi
+
 AC_ARG_ENABLE(music-cmd,
 [  --enable-music-cmd      support an external music player [default=yes]],
               , enable_music_cmd=yes)
@@ -138,6 +147,7 @@
 
 dnl Add Makefile conditionals
 AC_SUBST(MUSIC_SUBDIRS)
+AM_CONDITIONAL(VOC_SAMPLES, test x$enable_samples_voc = xyes)
 AM_CONDITIONAL(USE_MIKMOD, test x$enable_music_mod = xyes)
 AM_CONDITIONAL(USE_TIMIDITY, test x$enable_music_midi = xyes)
 
diff -urBbN --exclude=*CVS* SDL_mixer-virgin/mixer.c SDL_mixer/mixer.c
--- SDL_mixer-virgin/mixer.c	Thu May 10 11:17:57 2001
+++ SDL_mixer/mixer.c	Tue Jun  5 08:38:47 2001
@@ -270,6 +270,17 @@
 	return(audio_opened);
 }
 
+
+/*
+ * !!! FIXME: Ideally, we want a Mix_LoadSample_RW(), which will handle the
+ *             generic setup, then call the correct file format loader.
+ */
+
+#ifdef VOC_SAMPLES
+SDL_AudioSpec *Mix_LoadVOC_RW (SDL_RWops *src, int freesrc,
+		SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len);
+#endif
+
 /* Load a wave file */
 Mix_Chunk *Mix_LoadWAV_RW(SDL_RWops *src, int freesrc)
 {
@@ -278,6 +289,12 @@
 	SDL_AudioCVT wavecvt;
 	int samplesize;
 
+	/* rcg06012001 Make sure src is valid */
+	if ( ! src ) {
+		SDL_SetError("Mix_LoadWAV_RW with NULL SDL_RWops");
+		return(NULL);
+	}
+
 	/* Make sure audio has been opened */
 	if ( ! audio_opened ) {
 		SDL_SetError("Audio device hasn't been opened");
@@ -297,12 +314,22 @@
 		return(NULL);
 	}
 
+	/* rcg06012001 Handle Creative Labs .VOC format chunks. */
+#ifdef VOC_SAMPLES
+	if ( Mix_LoadVOC_RW(src, 0,
+		&wavespec, (Uint8 **)&chunk->abuf, &chunk->alen) == NULL ) {
+#endif
 	/* Load the WAV file into the chunk */
 	if ( SDL_LoadWAV_RW(src, freesrc,
 		&wavespec, (Uint8 **)&chunk->abuf, &chunk->alen) == NULL ) {
 		free(chunk);
 		return(NULL);
 	}
+
+#ifdef VOC_SAMPLES
+	}
+#endif
+
 #if 0
 	PrintFormat("Audio device", &mixer);
 	PrintFormat("-- Wave file", &wavespec);
diff -urBbN --exclude=*CVS* SDL_mixer-virgin/voc.c SDL_mixer/voc.c
--- SDL_mixer-virgin/voc.c	Wed Dec 31 16:00:00 1969
+++ SDL_mixer/voc.c	Tue Jun  5 10:56:51 2001
@@ -0,0 +1,467 @@
+/*
+    SDL_mixer:  An audio mixer library based on the SDL library
+    Copyright (C) 1997-1999  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    This is the source needed to decode a Creative Labs VOC file into a
+    waveform. It's pretty straightforward once you get going. The only
+    externally-callable function is Mix_LoadVOC_RW(), which is meant to
+    act as identically to SDL_LoadWAV_RW() as possible.
+
+    This file by Ryan C. Gordon (icculus at linuxgames.com).
+
+    Heavily borrowed from sox v12.17.1's voc.c.
+        (http://www.freshmeat.net/projects/sox/)
+*/
+
+/* $Id: voc.c,v 1.23 2001/05/10 18:17:57 icculus Exp $ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "SDL_mutex.h"
+#include "SDL_endian.h"
+#include "SDL_timer.h"
+
+#include "SDL_mixer.h"
+
+#ifndef VOC_SAMPLES
+#error There seems to be an error in your build configuration.
+#endif
+
+/* Private data for VOC file */
+typedef struct vocstuff {
+	Uint32	rest;			/* bytes remaining in current block */
+	Uint32	rate;			/* rate code (byte) of this chunk */
+	int 	silent;		/* sound or silence? */
+	Uint32	srate;			/* rate code (byte) of silence */
+	Uint32	blockseek;		/* start of current output block */
+	Uint32	samples;		/* number of samples output */
+	Uint32	size;		/* word length of data */
+	int 	channels;	/* number of sound channels */
+	int     extended;       /* Has an extended block been read? */
+} vs_t;
+
+/* Size field */ 
+/* SJB: note that the 1st 3 are sometimes used as sizeof(type) */
+#define	ST_SIZE_BYTE	1
+#define ST_SIZE_8BIT	1
+#define	ST_SIZE_WORD	2
+#define ST_SIZE_16BIT	2
+#define	ST_SIZE_DWORD	4
+#define ST_SIZE_32BIT	4
+#define	ST_SIZE_FLOAT	5
+#define ST_SIZE_DOUBLE	6
+#define ST_SIZE_IEEE	7	/* IEEE 80-bit floats. */
+
+/* Style field */
+#define ST_ENCODING_UNSIGNED	1 /* unsigned linear: Sound Blaster */
+#define ST_ENCODING_SIGN2	2 /* signed linear 2's comp: Mac */
+#define	ST_ENCODING_ULAW	3 /* U-law signed logs: US telephony, SPARC */
+#define ST_ENCODING_ALAW	4 /* A-law signed logs: non-US telephony */
+#define ST_ENCODING_ADPCM	5 /* Compressed PCM */
+#define ST_ENCODING_IMA_ADPCM	6 /* Compressed PCM */
+#define ST_ENCODING_GSM		7 /* GSM 6.10 33-byte frame lossy compression */
+
+#define	VOC_TERM	0
+#define	VOC_DATA	1
+#define	VOC_CONT	2
+#define	VOC_SILENCE	3
+#define	VOC_MARKER	4
+#define	VOC_TEXT	5
+#define	VOC_LOOP	6
+#define	VOC_LOOPEND	7
+#define VOC_EXTENDED    8
+#define VOC_DATA_16	9
+
+
+static inline int voc_check_header(SDL_RWops *src)
+{
+	/* VOC magic header */
+    Uint8  signature[20];  /* "Creative Voice File\032" */
+    Uint16 datablockofs;
+
+    SDL_RWseek(src, 0, SEEK_SET);
+
+	if (SDL_RWread(src, signature, sizeof (signature), 1) != 1)
+        return(0);
+
+    if (memcmp(signature, "Creative Voice File\032", sizeof (signature)) != 0) {
+		SDL_SetError("Unrecognized file type (not VOC)");
+        return(0);
+    }
+
+        /* get the offset where the first datablock is located */
+	if (SDL_RWread(src, &datablockofs, sizeof (Uint16), 1) != 1)
+        return(0);
+
+    datablockofs = SDL_SwapLE16(datablockofs);
+
+    if (SDL_RWseek(src, datablockofs, SEEK_SET) != datablockofs)
+        return(0);
+
+    return(1);  /* success! */
+} /* voc_check_header */
+
+
+/* Read next block header, save info, leave position at start of data */
+static int voc_get_block(SDL_RWops *src, vs_t *v, SDL_AudioSpec *spec)
+{
+    Uint8 bits24[3];
+	Uint8 uc, block;
+	Uint32 sblen;
+	Uint16 new_rate_short;
+	Uint32 new_rate_long;
+	Uint8 trash[6];
+    Uint16 period;
+	int i;
+
+	v->silent = 0;
+	while (v->rest == 0)
+    {
+		if (SDL_RWread(src, &block, sizeof (block), 1) != 1)
+            return 1;  /* assume that's the end of the file. */
+
+		if (block == VOC_TERM)
+			return 1;
+
+		if (SDL_RWread(src, bits24, sizeof (bits24), 1) != 1)
+            return 1;  /* assume that's the end of the file. */
+        
+		/* Size is an 24-bit value. Ugh. */
+        sblen = ( (bits24[0]) | (bits24[1] << 8) | (bits24[2] << 16) );
+
+		switch(block)
+        {
+		    case VOC_DATA:
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+
+    			/* When DATA block preceeded by an EXTENDED     */
+	    		/* block, the DATA blocks rate value is invalid */
+		        if (!v->extended)
+                {
+                    if (uc == 0)
+    			    {
+                        SDL_SetError("VOC Sample rate is zero?");
+		        	    return 0;
+                    }
+
+                    if ((v->rate != -1) && (uc != v->rate))
+                    {
+                        SDL_SetError("VOC sample rate codes differ");
+			            return 0;
+			        }
+
+			        v->rate = uc;
+			        spec->freq = 1000000.0/(256 - v->rate);
+			        v->channels = 1;
+			    }
+
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+
+                if (uc != 0)
+                {
+                    SDL_SetError("VOC decoder only interprets 8-bit data");
+                    return 0;
+                }
+
+    			v->extended = 0;
+	    		v->rest = sblen - 2;
+		    	v->size = ST_SIZE_BYTE;
+			    return 1;
+
+    		case VOC_DATA_16:
+                if (SDL_RWread(src, &new_rate_long, sizeof (new_rate_long), 1) != 1)
+                    return 0;
+                new_rate_long = SDL_SwapLE32(new_rate_long);
+		    	if (new_rate_long == 0)
+    			{
+    			    SDL_SetError("VOC Sample rate is zero?");
+    			    return 0;
+    			}
+    			if ((v->rate != -1) && (new_rate_long != v->rate))
+    			{
+    			    SDL_SetError("VOC sample rate codes differ");
+    			    return 0;
+    			}
+    			v->rate = new_rate_long;
+    			spec->freq = new_rate_long;
+
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+
+    			switch (uc)
+    			{
+    			    case 8:  v->size = ST_SIZE_BYTE; break;
+    			    case 16: v->size = ST_SIZE_WORD; break;
+    			    default:
+    					SDL_SetError("VOC with unknown data size");
+    					return 0;
+    			}
+
+                if (SDL_RWread(src, &v->channels, sizeof (Uint8), 1) != 1)
+                    return 0;
+
+                if (SDL_RWread(src, trash, sizeof (Uint8), 6) != 6)
+                    return 0;
+
+    			v->rest = sblen - 12;
+    			return 1;
+
+    		case VOC_CONT:
+    			v->rest = sblen;
+    			return 1;
+
+    		case VOC_SILENCE:
+                if (SDL_RWread(src, &period, sizeof (period), 1) != 1)
+                    return 0;
+                period = SDL_SwapLE16(period);
+
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+    			if (uc == 0)
+    			{
+    				SDL_SetError("VOC silence sample rate is zero");
+    				return 0;
+    			}
+
+    			/*
+    			 * Some silence-packed files have gratuitously
+    			 * different sample rate codes in silence.
+    			 * Adjust period.
+    			 */
+    			if ((v->rate != -1) && (uc != v->rate))
+    				period = (period * (256 - uc))/(256 - v->rate);
+    			else
+    				v->rate = uc;
+    			v->rest = period;
+    			v->silent = 1;
+    			return 1;
+
+    		case VOC_LOOP:
+    		case VOC_LOOPEND:
+                for(i = 0; i < sblen; i++)   /* skip repeat loops. */
+                {
+                    if (SDL_RWread(src, trash, sizeof (Uint8), 1) != 1)
+                        return 0;
+                }
+    			break;
+
+    		case VOC_EXTENDED:
+    			/* An Extended block is followed by a data block */
+    			/* Set this byte so we know to use the rate      */
+    			/* value from the extended block and not the     */
+    			/* data block.					 */
+    			v->extended = 1;
+                if (SDL_RWread(src, &new_rate_short, sizeof (new_rate_short), 1) != 1)
+                    return 0;
+                new_rate_short = SDL_SwapLE16(new_rate_short);
+    			if (new_rate_short == 0)
+    			{
+    			   SDL_SetError("VOC sample rate is zero");
+    			   return 0;
+    			}
+    			if ((v->rate != -1) && (new_rate_short != v->rate))
+    			{
+    			   SDL_SetError("VOC sample rate codes differ");
+    			   return 0;
+    			}
+    			v->rate = new_rate_short;
+
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+
+    			if (uc != 0)
+    			{
+    				SDL_SetError("VOC decoder only interprets 8-bit data");
+    				return 0;
+    			}
+
+                if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
+                    return 0;
+
+    			if (uc)
+    				spec->channels = 2;  /* Stereo */
+    			/* Needed number of channels before finishing
+    			   compute for rate */
+    			spec->freq = (256000000L/(65536L - v->rate))/spec->channels;
+    			/* An extended block must be followed by a data */
+    			/* block to be valid so loop back to top so it  */
+    			/* can be grabed.				*/
+    			continue;
+
+    		case VOC_MARKER:
+                if (SDL_RWread(src, trash, sizeof (Uint8), 2) != 2)
+                    return 0;
+
+    			/* Falling! Falling! */
+
+    		default:  /* text block or other krapola. */
+    			for(i = 0; i < sblen; i++)
+                {
+                    if (SDL_RWread(src, &trash, sizeof (Uint8), 1) != 1)
+                        return 0;
+                }
+
+                if (block == VOC_TEXT)
+        			continue;	/* get next block */
+    	}
+    }
+
+	return 1;
+}
+
+
+static int voc_read(SDL_RWops *src, vs_t *v, Uint8 *buf, SDL_AudioSpec *spec)
+{
+	int done = 0;
+	int rc;
+	Uint16 us;
+	Uint8 uc;
+    Uint8 silence = 0x80;
+
+	if (v->rest == 0)
+	{
+		if (!voc_get_block(src, v, spec))
+		    return 0;
+	}
+
+	if (v->rest == 0)
+		return 0;
+
+	if (v->silent)
+    {
+	    if (v->size == ST_SIZE_WORD)
+    	    silence = 0x00;
+
+		/* Fill in silence */
+        memset(buf, silence, v->rest);
+        done = v->rest;
+        v->rest = 0;
+	}
+
+    else
+    {
+        done = SDL_RWread(src, buf, 1, v->rest);
+        v->rest -= done;
+        if (v->size == ST_SIZE_WORD)
+        {
+            done >>= 1;
+            #if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
+                for (; v->rest > 0; v->rest -= 2)
+                {
+                    *((Uint16 *) buf) = SDL_SwapLE16(*((Uint16 *) buf));
+                    ((Uint16 *) buf)++;
+                }
+            #endif
+        }
+	}
+
+	return done;
+} /* voc_read */
+
+
+/* don't call this directly; use Mix_LoadWAV_RW() for now. */
+SDL_AudioSpec *Mix_LoadVOC_RW (SDL_RWops *src, int freesrc,
+		SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
+{
+	vs_t v;
+	int was_error = 1;
+	int lenread;
+	int samplesize;
+    Uint8 *fillptr;
+    void *ptr;
+
+	if ( (!src) || (!audio_buf) || (!audio_len) )   /* sanity checks. */
+		goto done;
+
+    if ( !voc_check_header(src) )
+        goto done;
+
+	v.rate = -1;
+	v.rest = 0;
+	v.extended = 0;
+    *audio_buf = NULL;
+    *audio_len = 0;
+    memset(spec, '\0', sizeof (SDL_AudioSpec));
+
+    if (!voc_get_block(src, &v, spec))
+        goto done;
+
+	if (v.rate == -1)
+	{
+		SDL_SetError("VOC data had no sound!");
+        goto done;
+	}
+
+	spec->format = ((v.size == ST_SIZE_WORD) ? AUDIO_S16 : AUDIO_U8);
+    if (spec->channels == 0)
+        spec->channels = v.channels;
+
+    *audio_len = v.rest;
+    *audio_buf = malloc(v.rest);
+    if (*audio_buf == NULL)
+        goto done;
+
+    fillptr = *audio_buf;
+
+    while (voc_read(src, &v, fillptr, spec) > 0)
+    {
+        if (!voc_get_block(src, &v, spec))
+            goto done;
+
+        *audio_len += v.rest;
+        ptr = realloc(*audio_buf, *audio_len);
+        if (ptr == NULL)
+        {
+            free(*audio_buf);
+            *audio_buf = NULL;
+            *audio_len = 0;
+            goto done;
+        }
+
+        *audio_buf = ptr;
+        fillptr = ((Uint8 *) ptr) + (*audio_len - v.rest);
+    }
+
+    spec->samples = (*audio_len / v.size);
+
+    was_error = 0;  /* success, baby! */
+
+	/* Don't return a buffer that isn't a multiple of samplesize */
+	samplesize = ((spec->format & 0xFF)/8)*spec->channels;
+	*audio_len &= ~(samplesize-1);
+
+done:
+	if (src)
+    {
+        if (freesrc)
+		    SDL_RWclose(src);
+	    else
+            SDL_RWseek(src, 0, SEEK_SET);
+    }
+
+	if ( was_error )
+		spec = NULL;
+
+	return(spec);
+} /* Mix_LoadVOC_RW */
+
+/* end of voc.c ... */
+


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