slouken@111: /*
slouken@518:   SDL_mixer:  An audio mixer library based on the SDL library
slouken@601:   Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
slouken@111: 
slouken@518:   This software is provided 'as-is', without any express or implied
slouken@518:   warranty.  In no event will the authors be held liable for any damages
slouken@518:   arising from the use of this software.
slouken@111: 
slouken@518:   Permission is granted to anyone to use this software for any purpose,
slouken@518:   including commercial applications, and to alter it and redistribute it
slouken@518:   freely, subject to the following restrictions:
slouken@111: 
slouken@518:   1. The origin of this software must not be misrepresented; you must not
slouken@518:      claim that you wrote the original software. If you use this software
slouken@518:      in a product, an acknowledgment in the product documentation would be
slouken@518:      appreciated but is not required.
slouken@518:   2. Altered source versions must be plainly marked as such, and must not be
slouken@518:      misrepresented as being the original software.
slouken@518:   3. This notice may not be removed or altered from any source distribution.
slouken@111: 
slouken@518:   This is the source needed to decode a Creative Labs VOC file into a
slouken@518:   waveform. It's pretty straightforward once you get going. The only
slouken@518:   externally-callable function is Mix_LoadVOC_RW(), which is meant to
slouken@518:   act as identically to SDL_LoadWAV_RW() as possible.
slouken@111: 
slouken@518:   This file by Ryan C. Gordon (icculus@icculus.org).
slouken@111: 
slouken@518:   Heavily borrowed from sox v12.17.1's voc.c.
slouken@111:         (http://www.freshmeat.net/projects/sox/)
slouken@111: */
slouken@111: 
slouken@111: /* $Id$ */
slouken@111: 
slouken@111: #include <stdio.h>
slouken@111: #include <stdlib.h>
slouken@111: #include <string.h>
slouken@111: 
slouken@111: #include "SDL_mutex.h"
slouken@111: #include "SDL_endian.h"
slouken@111: #include "SDL_timer.h"
slouken@111: 
slouken@111: #include "SDL_mixer.h"
slouken@111: #include "load_voc.h"
slouken@111: 
slouken@111: /* Private data for VOC file */
slouken@111: typedef struct vocstuff {
slouken@111: 	Uint32	rest;			/* bytes remaining in current block */
slouken@111: 	Uint32	rate;			/* rate code (byte) of this chunk */
slouken@111: 	int 	silent;		/* sound or silence? */
slouken@111: 	Uint32	srate;			/* rate code (byte) of silence */
slouken@111: 	Uint32	blockseek;		/* start of current output block */
slouken@111: 	Uint32	samples;		/* number of samples output */
slouken@111: 	Uint32	size;		/* word length of data */
slouken@116: 	Uint8 	channels;	/* number of sound channels */
slouken@144: 	int     has_extended;       /* Has an extended block been read? */
slouken@111: } vs_t;
slouken@111: 
slouken@111: /* Size field */ 
slouken@111: /* SJB: note that the 1st 3 are sometimes used as sizeof(type) */
slouken@111: #define	ST_SIZE_BYTE	1
slouken@111: #define ST_SIZE_8BIT	1
slouken@111: #define	ST_SIZE_WORD	2
slouken@111: #define ST_SIZE_16BIT	2
slouken@111: #define	ST_SIZE_DWORD	4
slouken@111: #define ST_SIZE_32BIT	4
slouken@111: #define	ST_SIZE_FLOAT	5
slouken@111: #define ST_SIZE_DOUBLE	6
slouken@111: #define ST_SIZE_IEEE	7	/* IEEE 80-bit floats. */
slouken@111: 
slouken@111: /* Style field */
slouken@111: #define ST_ENCODING_UNSIGNED	1 /* unsigned linear: Sound Blaster */
slouken@111: #define ST_ENCODING_SIGN2	2 /* signed linear 2's comp: Mac */
slouken@111: #define	ST_ENCODING_ULAW	3 /* U-law signed logs: US telephony, SPARC */
slouken@111: #define ST_ENCODING_ALAW	4 /* A-law signed logs: non-US telephony */
slouken@111: #define ST_ENCODING_ADPCM	5 /* Compressed PCM */
slouken@111: #define ST_ENCODING_IMA_ADPCM	6 /* Compressed PCM */
slouken@111: #define ST_ENCODING_GSM		7 /* GSM 6.10 33-byte frame lossy compression */
slouken@111: 
slouken@111: #define	VOC_TERM	0
slouken@111: #define	VOC_DATA	1
slouken@111: #define	VOC_CONT	2
slouken@111: #define	VOC_SILENCE	3
slouken@111: #define	VOC_MARKER	4
slouken@111: #define	VOC_TEXT	5
slouken@111: #define	VOC_LOOP	6
slouken@111: #define	VOC_LOOPEND	7
slouken@111: #define VOC_EXTENDED    8
slouken@111: #define VOC_DATA_16	9
slouken@111: 
slouken@111: 
slouken@114: static int voc_check_header(SDL_RWops *src)
slouken@111: {
slouken@111:     /* VOC magic header */
slouken@111:     Uint8  signature[20];  /* "Creative Voice File\032" */
slouken@111:     Uint16 datablockofs;
slouken@111: 
slouken@473:     SDL_RWseek(src, 0, RW_SEEK_SET);
slouken@111: 
slouken@111:     if (SDL_RWread(src, signature, sizeof (signature), 1) != 1)
slouken@111:         return(0);
slouken@111: 
slouken@111:     if (memcmp(signature, "Creative Voice File\032", sizeof (signature)) != 0) {
slouken@111:         SDL_SetError("Unrecognized file type (not VOC)");
slouken@111:         return(0);
slouken@111:     }
slouken@111: 
slouken@111:         /* get the offset where the first datablock is located */
slouken@111:     if (SDL_RWread(src, &datablockofs, sizeof (Uint16), 1) != 1)
slouken@111:         return(0);
slouken@111: 
slouken@111:     datablockofs = SDL_SwapLE16(datablockofs);
slouken@111: 
slouken@473:     if (SDL_RWseek(src, datablockofs, RW_SEEK_SET) != datablockofs)
slouken@111:         return(0);
slouken@111: 
slouken@111:     return(1);  /* success! */
slouken@111: } /* voc_check_header */
slouken@111: 
slouken@111: 
slouken@111: /* Read next block header, save info, leave position at start of data */
slouken@111: static int voc_get_block(SDL_RWops *src, vs_t *v, SDL_AudioSpec *spec)
slouken@111: {
slouken@111:     Uint8 bits24[3];
slouken@111:     Uint8 uc, block;
slouken@111:     Uint32 sblen;
slouken@111:     Uint16 new_rate_short;
slouken@111:     Uint32 new_rate_long;
slouken@111:     Uint8 trash[6];
slouken@111:     Uint16 period;
slouken@114:     unsigned int i;
slouken@111: 
slouken@111:     v->silent = 0;
slouken@111:     while (v->rest == 0)
slouken@111:     {
slouken@111:         if (SDL_RWread(src, &block, sizeof (block), 1) != 1)
slouken@111:             return 1;  /* assume that's the end of the file. */
slouken@111: 
slouken@111:         if (block == VOC_TERM)
slouken@111:             return 1;
slouken@111: 
slouken@111:         if (SDL_RWread(src, bits24, sizeof (bits24), 1) != 1)
slouken@111:             return 1;  /* assume that's the end of the file. */
slouken@111:         
slouken@111:         /* Size is an 24-bit value. Ugh. */
slouken@111:         sblen = ( (bits24[0]) | (bits24[1] << 8) | (bits24[2] << 16) );
slouken@111: 
slouken@111:         switch(block)
slouken@111:         {
slouken@111:             case VOC_DATA:
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 /* When DATA block preceeded by an EXTENDED     */
slouken@111:                 /* block, the DATA blocks rate value is invalid */
slouken@144:                 if (!v->has_extended)
slouken@111:                 {
slouken@111:                     if (uc == 0)
slouken@111:                     {
slouken@111:                         SDL_SetError("VOC Sample rate is zero?");
slouken@111:                         return 0;
slouken@111:                     }
slouken@111: 
slouken@111:                     if ((v->rate != -1) && (uc != v->rate))
slouken@111:                     {
slouken@111:                         SDL_SetError("VOC sample rate codes differ");
slouken@111:                         return 0;
slouken@111:                     }
slouken@111: 
slouken@111:                     v->rate = uc;
slouken@114:                     spec->freq = (Uint16)(1000000.0/(256 - v->rate));
slouken@111:                     v->channels = 1;
slouken@111:                 }
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 if (uc != 0)
slouken@111:                 {
slouken@111:                     SDL_SetError("VOC decoder only interprets 8-bit data");
slouken@111:                     return 0;
slouken@111:                 }
slouken@111: 
slouken@144:                 v->has_extended = 0;
slouken@111:                 v->rest = sblen - 2;
slouken@111:                 v->size = ST_SIZE_BYTE;
slouken@111:                 return 1;
slouken@111: 
slouken@111:             case VOC_DATA_16:
slouken@111:                 if (SDL_RWread(src, &new_rate_long, sizeof (new_rate_long), 1) != 1)
slouken@111:                     return 0;
slouken@111:                 new_rate_long = SDL_SwapLE32(new_rate_long);
slouken@111:                 if (new_rate_long == 0)
slouken@111:                 {
slouken@111:                     SDL_SetError("VOC Sample rate is zero?");
slouken@111:                     return 0;
slouken@111:                 }
slouken@111:                 if ((v->rate != -1) && (new_rate_long != v->rate))
slouken@111:                 {
slouken@111:                     SDL_SetError("VOC sample rate codes differ");
slouken@111:                     return 0;
slouken@111:                 }
slouken@111:                 v->rate = new_rate_long;
slouken@111:                 spec->freq = new_rate_long;
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 switch (uc)
slouken@111:                 {
slouken@111:                     case 8:  v->size = ST_SIZE_BYTE; break;
slouken@111:                     case 16: v->size = ST_SIZE_WORD; break;
slouken@111:                     default:
slouken@111:                         SDL_SetError("VOC with unknown data size");
slouken@111:                         return 0;
slouken@111:                 }
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &v->channels, sizeof (Uint8), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 if (SDL_RWread(src, trash, sizeof (Uint8), 6) != 6)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 v->rest = sblen - 12;
slouken@111:                 return 1;
slouken@111: 
slouken@111:             case VOC_CONT:
slouken@111:                 v->rest = sblen;
slouken@111:                 return 1;
slouken@111: 
slouken@111:             case VOC_SILENCE:
slouken@111:                 if (SDL_RWread(src, &period, sizeof (period), 1) != 1)
slouken@111:                     return 0;
slouken@111:                 period = SDL_SwapLE16(period);
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111:                 if (uc == 0)
slouken@111:                 {
slouken@111:                     SDL_SetError("VOC silence sample rate is zero");
slouken@111:                     return 0;
slouken@111:                 }
slouken@111: 
slouken@111:                 /*
slouken@111:                  * Some silence-packed files have gratuitously
slouken@111:                  * different sample rate codes in silence.
slouken@111:                  * Adjust period.
slouken@111:                  */
slouken@111:                 if ((v->rate != -1) && (uc != v->rate))
slouken@310:                     period = (Uint16)((period * (256 - uc))/(256 - v->rate));
slouken@111:                 else
slouken@111:                     v->rate = uc;
slouken@111:                 v->rest = period;
slouken@111:                 v->silent = 1;
slouken@111:                 return 1;
slouken@111: 
slouken@111:             case VOC_LOOP:
slouken@111:             case VOC_LOOPEND:
slouken@111:                 for(i = 0; i < sblen; i++)   /* skip repeat loops. */
slouken@111:                 {
slouken@111:                     if (SDL_RWread(src, trash, sizeof (Uint8), 1) != 1)
slouken@111:                         return 0;
slouken@111:                 }
slouken@111:                 break;
slouken@111: 
slouken@111:             case VOC_EXTENDED:
slouken@111:                 /* An Extended block is followed by a data block */
slouken@111:                 /* Set this byte so we know to use the rate      */
slouken@111:                 /* value from the extended block and not the     */
slouken@111:                 /* data block.                     */
slouken@144:                 v->has_extended = 1;
slouken@111:                 if (SDL_RWread(src, &new_rate_short, sizeof (new_rate_short), 1) != 1)
slouken@111:                     return 0;
slouken@111:                 new_rate_short = SDL_SwapLE16(new_rate_short);
slouken@111:                 if (new_rate_short == 0)
slouken@111:                 {
slouken@111:                    SDL_SetError("VOC sample rate is zero");
slouken@111:                    return 0;
slouken@111:                 }
slouken@111:                 if ((v->rate != -1) && (new_rate_short != v->rate))
slouken@111:                 {
slouken@111:                    SDL_SetError("VOC sample rate codes differ");
slouken@111:                    return 0;
slouken@111:                 }
slouken@111:                 v->rate = new_rate_short;
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 if (uc != 0)
slouken@111:                 {
slouken@111:                     SDL_SetError("VOC decoder only interprets 8-bit data");
slouken@111:                     return 0;
slouken@111:                 }
slouken@111: 
slouken@111:                 if (SDL_RWread(src, &uc, sizeof (uc), 1) != 1)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 if (uc)
slouken@111:                     spec->channels = 2;  /* Stereo */
slouken@111:                 /* Needed number of channels before finishing
slouken@111:                    compute for rate */
slouken@111:                 spec->freq = (256000000L/(65536L - v->rate))/spec->channels;
slouken@111:                 /* An extended block must be followed by a data */
slouken@111:                 /* block to be valid so loop back to top so it  */
slouken@111:                 /* can be grabed.                */
slouken@111:                 continue;
slouken@111: 
slouken@111:             case VOC_MARKER:
slouken@111:                 if (SDL_RWread(src, trash, sizeof (Uint8), 2) != 2)
slouken@111:                     return 0;
slouken@111: 
slouken@111:                 /* Falling! Falling! */
slouken@111: 
slouken@111:             default:  /* text block or other krapola. */
slouken@111:                 for(i = 0; i < sblen; i++)
slouken@111:                 {
slouken@111:                     if (SDL_RWread(src, &trash, sizeof (Uint8), 1) != 1)
slouken@111:                         return 0;
slouken@111:                 }
slouken@111: 
slouken@111:                 if (block == VOC_TEXT)
slouken@111:                     continue;    /* get next block */
slouken@111:         }
slouken@111:     }
slouken@111: 
slouken@111:     return 1;
slouken@111: }
slouken@111: 
slouken@111: 
slouken@111: static int voc_read(SDL_RWops *src, vs_t *v, Uint8 *buf, SDL_AudioSpec *spec)
slouken@111: {
slouken@111:     int done = 0;
slouken@111:     Uint8 silence = 0x80;
slouken@111: 
slouken@111:     if (v->rest == 0)
slouken@111:     {
slouken@111:         if (!voc_get_block(src, v, spec))
slouken@111:             return 0;
slouken@111:     }
slouken@111: 
slouken@111:     if (v->rest == 0)
slouken@111:         return 0;
slouken@111: 
slouken@111:     if (v->silent)
slouken@111:     {
slouken@111:         if (v->size == ST_SIZE_WORD)
slouken@111:             silence = 0x00;
slouken@111: 
slouken@111:         /* Fill in silence */
slouken@111:         memset(buf, silence, v->rest);
slouken@111:         done = v->rest;
slouken@111:         v->rest = 0;
slouken@111:     }
slouken@111: 
slouken@111:     else
slouken@111:     {
slouken@111:         done = SDL_RWread(src, buf, 1, v->rest);
slouken@111:         v->rest -= done;
slouken@111:         if (v->size == ST_SIZE_WORD)
slouken@111:         {
slouken@111:             #if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
slouken@180:                 Uint16 *samples = (Uint16 *)buf;
slouken@111:                 for (; v->rest > 0; v->rest -= 2)
slouken@111:                 {
slouken@180:                     *samples = SDL_SwapLE16(*samples);
slouken@180:                     samples++;
slouken@111:                 }
slouken@111:             #endif
slouken@180:             done >>= 1;
slouken@111:         }
slouken@111:     }
slouken@111: 
slouken@111:     return done;
slouken@111: } /* voc_read */
slouken@111: 
slouken@111: 
slouken@111: /* don't call this directly; use Mix_LoadWAV_RW() for now. */
slouken@111: SDL_AudioSpec *Mix_LoadVOC_RW (SDL_RWops *src, int freesrc,
slouken@111:         SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
slouken@111: {
slouken@111:     vs_t v;
slouken@111:     int was_error = 1;
slouken@111:     int samplesize;
slouken@111:     Uint8 *fillptr;
slouken@111:     void *ptr;
slouken@111: 
slouken@111:     if ( (!src) || (!audio_buf) || (!audio_len) )   /* sanity checks. */
slouken@111:         goto done;
slouken@111: 
slouken@111:     if ( !voc_check_header(src) )
slouken@111:         goto done;
slouken@111: 
slouken@111:     v.rate = -1;
slouken@111:     v.rest = 0;
slouken@144:     v.has_extended = 0;
slouken@111:     *audio_buf = NULL;
slouken@111:     *audio_len = 0;
slouken@111:     memset(spec, '\0', sizeof (SDL_AudioSpec));
slouken@111: 
slouken@111:     if (!voc_get_block(src, &v, spec))
slouken@111:         goto done;
slouken@111: 
slouken@111:     if (v.rate == -1)
slouken@111:     {
slouken@111:         SDL_SetError("VOC data had no sound!");
slouken@111:         goto done;
slouken@111:     }
slouken@111: 
slouken@111:     spec->format = ((v.size == ST_SIZE_WORD) ? AUDIO_S16 : AUDIO_U8);
slouken@111:     if (spec->channels == 0)
slouken@111:         spec->channels = v.channels;
slouken@111: 
slouken@111:     *audio_len = v.rest;
slouken@561:     *audio_buf = SDL_malloc(v.rest);
slouken@111:     if (*audio_buf == NULL)
slouken@111:         goto done;
slouken@111: 
slouken@111:     fillptr = *audio_buf;
slouken@111: 
slouken@111:     while (voc_read(src, &v, fillptr, spec) > 0)
slouken@111:     {
slouken@111:         if (!voc_get_block(src, &v, spec))
slouken@111:             goto done;
slouken@111: 
slouken@111:         *audio_len += v.rest;
slouken@561:         ptr = SDL_realloc(*audio_buf, *audio_len);
slouken@111:         if (ptr == NULL)
slouken@111:         {
slouken@561:             SDL_free(*audio_buf);
slouken@111:             *audio_buf = NULL;
slouken@111:             *audio_len = 0;
slouken@111:             goto done;
slouken@111:         }
slouken@111: 
slouken@111:         *audio_buf = ptr;
slouken@111:         fillptr = ((Uint8 *) ptr) + (*audio_len - v.rest);
slouken@111:     }
slouken@111: 
slouken@310:     spec->samples = (Uint16)(*audio_len / v.size);
slouken@111: 
slouken@111:     was_error = 0;  /* success, baby! */
slouken@111: 
slouken@111:     /* Don't return a buffer that isn't a multiple of samplesize */
slouken@111:     samplesize = ((spec->format & 0xFF)/8)*spec->channels;
slouken@111:     *audio_len &= ~(samplesize-1);
slouken@111: 
slouken@111: done:
slouken@111:     if (src)
slouken@111:     {
slouken@111:         if (freesrc)
slouken@111:             SDL_RWclose(src);
slouken@111:         else
slouken@473:             SDL_RWseek(src, 0, RW_SEEK_SET);
slouken@111:     }
slouken@111: 
slouken@111:     if ( was_error )
slouken@111:         spec = NULL;
slouken@111: 
slouken@111:     return(spec);
slouken@111: } /* Mix_LoadVOC_RW */
slouken@111: 
slouken@111: /* end of load_voc.c ... */