/*

* SDL_sound -- An abstract sound format decoding API.

* Copyright (C) 2001 Ryan C. Gordon.

*

* This library is free software; you can redistribute it and/or

* modify it under the terms of the GNU Lesser General Public

* License as published by the Free Software Foundation; either

* version 2.1 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

* Lesser General Public License for more details.

*

* You should have received a copy of the GNU Lesser General Public

* License along with this library; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

*/

/*

* Sun/NeXT .au decoder for SDL_sound.

* Formats supported: 8 and 16 bit linear PCM, 8 bit µ-law.

* Files without valid header are assumed to be 8 bit µ-law, 8kHz, mono.

*

* Please see the file COPYING in the source's root directory.

*

* This file written by Mattias Engdegård. (f91-men@nada.kth.se)

*/

#if HAVE_CONFIG_H

# include <config.h>

#endif

#ifdef SOUND_SUPPORTS_AU

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "SDL_sound.h"

#define __SDL_SOUND_INTERNAL__

#include "SDL_sound_internal.h"

static int AU_init(void);

static void AU_quit(void);

static int AU_open(Sound_Sample *sample, const char *ext);

static void AU_close(Sound_Sample *sample);

static Uint32 AU_read(Sound_Sample *sample);

/*

* Sometimes the extension ".snd" is used for these files (mostly on the NeXT),

* and the magic number comes from this. However it may clash with other

* formats and is somewhat of an anachronism, so only .au is used here.

*/

static const char *extensions_au[] = { "AU", NULL };

const Sound_DecoderFunctions __Sound_DecoderFunctions_AU =

{

{

extensions_au,

"Sun/NeXT audio file format",

"Mattias Engdegård <f91-men@nada.kth.se>",

"http://www.icculus.org/SDL_sound/"

},

AU_init, /* init() method */

AU_quit, /* quit() method */

AU_open, /* open() method */

AU_close, /* close() method */

AU_read, /* read() method */

AU_rewind, /* rewind() method */

AU_seek /* seek() method */

};

/* no init/deinit needed */

static int AU_init(void)

{

return(1);

static void AU_quit(void)

{

/* no-op. */

struct au_file_hdr

{

Uint32 magic;

Uint32 hdr_size;

Uint32 data_size;

Uint32 encoding;

Uint32 sample_rate;

Uint32 channels;

};

#define HDR_SIZE 24

enum

{

AU_ENC_ULAW_8 = 1, /* 8-bit ISDN µ-law */

AU_ENC_LINEAR_8 = 2, /* 8-bit linear PCM */

AU_ENC_LINEAR_16 = 3, /* 16-bit linear PCM */

/* the rest are unsupported (I have never seen them in the wild) */

AU_ENC_LINEAR_24 = 4, /* 24-bit linear PCM */

AU_ENC_LINEAR_32 = 5, /* 32-bit linear PCM */

AU_ENC_FLOAT = 6, /* 32-bit IEEE floating point */

AU_ENC_DOUBLE = 7, /* 64-bit IEEE floating point */

/* more Sun formats, not supported either */

AU_ENC_ADPCM_G721 = 23,

AU_ENC_ADPCM_G722 = 24,

AU_ENC_ADPCM_G723_3 = 25,

AU_ENC_ADPCM_G723_5 = 26,

AU_ENC_ALAW_8 = 27

};

struct audec

{

Uint32 total;

Uint32 remaining;

Uint32 start_offset;

int encoding;

};

/*

* Read in the AU header from disk. This makes this process safe

* regardless of the processor's byte order or how the au_file_hdr

* structure is packed.

*/

static int read_au_header(SDL_RWops *rw, struct au_file_hdr *hdr)

{

if (SDL_RWread(rw, &hdr->magic, sizeof (hdr->magic), 1) != 1)

return(0);

hdr->magic = SDL_SwapBE32(hdr->magic);

if (SDL_RWread(rw, &hdr->hdr_size, sizeof (hdr->hdr_size), 1) != 1)

return(0);

hdr->hdr_size = SDL_SwapBE32(hdr->hdr_size);

if (SDL_RWread(rw, &hdr->data_size, sizeof (hdr->data_size), 1) != 1)

return(0);

hdr->data_size = SDL_SwapBE32(hdr->data_size);

if (SDL_RWread(rw, &hdr->encoding, sizeof (hdr->encoding), 1) != 1)

return(0);

hdr->encoding = SDL_SwapBE32(hdr->encoding);

if (SDL_RWread(rw, &hdr->sample_rate, sizeof (hdr->sample_rate), 1) != 1)

return(0);

hdr->sample_rate = SDL_SwapBE32(hdr->sample_rate);

if (SDL_RWread(rw, &hdr->channels, sizeof (hdr->channels), 1) != 1)

return(0);

hdr->channels = SDL_SwapBE32(hdr->channels);

return(1);

} /* read_au_header */

static int AU_open(Sound_Sample *sample, const char *ext)

{

Sound_SampleInternal *internal = sample->opaque;

SDL_RWops *rw = internal->rw;

char c;

/* read_au_header() will do byte order swapping. */

BAIL_IF_MACRO(!read_au_header(rw, &hdr), "AU: bad header", 0);

dec = malloc(sizeof *dec);

BAIL_IF_MACRO(dec == NULL, ERR_OUT_OF_MEMORY, 0);

internal->decoder_private = dec;

if (hdr.magic == AU_MAGIC)

{

/* valid magic */

switch(dec->encoding)

{

case AU_ENC_ULAW_8:

/* Convert 8-bit µ-law to 16-bit linear on the fly. This is

slightly wasteful if the audio driver must convert them

back, but µ-law only devices are rare (mostly _old_ Suns) */

sample->actual.format = AUDIO_S16SYS;

break;

case AU_ENC_LINEAR_8:

sample->actual.format = AUDIO_S8;

break;

case AU_ENC_LINEAR_16:

sample->actual.format = AUDIO_S16MSB;

break;

default:

free(dec);

sample->actual.rate = hdr.sample_rate;

sample->actual.channels = hdr.channels;

dec->remaining = hdr.data_size;

hsize = hdr.hdr_size;

/* skip remaining part of header (input may be unseekable) */

for (i = HDR_SIZE; i < hsize; i++)

{

if (SDL_RWread(rw, &c, 1, 1) != 1)

{

free(dec);

BAIL_MACRO(ERR_IO_ERROR, 0);

} /* if */

} /* for */

else if (__Sound_strcasecmp(ext, "au") == 0)

{

/*

* A number of files in the wild have the .au extension but no valid

* header; these are traditionally assumed to be 8kHz µ-law. Handle

* them here only if the extension is recognized.

*/

SNDDBG(("AU: Invalid header, assuming raw 8kHz µ-law.\n"));

/* if seeking fails, we lose 24 samples. big deal */

SDL_RWseek(rw, -HDR_SIZE, SEEK_CUR);

dec->encoding = AU_ENC_ULAW_8;

dec->remaining = (Uint32)-1; /* no limit */

sample->actual.format = AUDIO_S16SYS;

sample->actual.rate = 8000;

sample->actual.channels = 1;

} /* else if */

else

{

free(dec);

} /* else */

bytes_per_second = ( ( dec->encoding == AU_ENC_LINEAR_16 ) ? 2 : 1 )

* sample->actual.rate * sample->actual.channels ;

internal->total_time = ((dec->remaining == -1) ? (-1) :

( ( dec->remaining / bytes_per_second ) * 1000 ) +

( ( dec->remaining % bytes_per_second ) * 1000 /

bytes_per_second ) );

dec->total = dec->remaining;

dec->start_offset = SDL_RWtell(rw);

SNDDBG(("AU: Accepting data stream.\n"));

return(1);

} /* AU_open */

static void AU_close(Sound_Sample *sample)

{

Sound_SampleInternal *internal = sample->opaque;

free(internal->decoder_private);

} /* AU_close */

/* table to convert from µ-law encoding to signed 16-bit samples,

generated by a throwaway perl script */

static Sint16 ulaw_to_linear[256] = {

-32124,-31100,-30076,-29052,-28028,-27004,-25980,-24956,

-23932,-22908,-21884,-20860,-19836,-18812,-17788,-16764,

-15996,-15484,-14972,-14460,-13948,-13436,-12924,-12412,

-11900,-11388,-10876,-10364, -9852, -9340, -8828, -8316,

-7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140,

-5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092,

-3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004,

-2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980,

-1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436,

-1372, -1308, -1244, -1180, -1116, -1052, -988, -924,

-876, -844, -812, -780, -748, -716, -684, -652,

-620, -588, -556, -524, -492, -460, -428, -396,

-372, -356, -340, -324, -308, -292, -276, -260,

-244, -228, -212, -196, -180, -164, -148, -132,

-120, -112, -104, -96, -88, -80, -72, -64,

-56, -48, -40, -32, -24, -16, -8, 0,

32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956,

23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764,

15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412,

11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316,

7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140,

5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092,

3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004,

2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980,

1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436,

1372, 1308, 1244, 1180, 1116, 1052, 988, 924,

876, 844, 812, 780, 748, 716, 684, 652,

620, 588, 556, 524, 492, 460, 428, 396,

372, 356, 340, 324, 308, 292, 276, 260,

244, 228, 212, 196, 180, 164, 148, 132,

120, 112, 104, 96, 88, 80, 72, 64,

56, 48, 40, 32, 24, 16, 8, 0

};

static Uint32 AU_read(Sound_Sample *sample)

{

int ret;

Sound_SampleInternal *internal = sample->opaque;

struct audec *dec = internal->decoder_private;

int maxlen;

Uint8 *buf;

maxlen = internal->buffer_size;

buf = internal->buffer;

if (dec->encoding == AU_ENC_ULAW_8)

{

/* We read µ-law samples into the second half of the buffer, so

we can expand them to 16-bit samples afterwards */

maxlen >>= 1;

buf += maxlen;

maxlen = dec->remaining;

ret = SDL_RWread(internal->rw, buf, 1, maxlen);

if (ret == 0)

sample->flags |= SOUND_SAMPLEFLAG_EOF;

else if (ret == -1)

sample->flags |= SOUND_SAMPLEFLAG_ERROR;

else

{

dec->remaining -= ret;

if (ret < maxlen)

sample->flags |= SOUND_SAMPLEFLAG_EAGAIN;

if (dec->encoding == AU_ENC_ULAW_8)

{

int i;

Sint16 *dst = internal->buffer;

for (i = 0; i < ret; i++)

dst[i] = ulaw_to_linear[buf[i]];

ret <<= 1; /* return twice as much as read */

} /* if */

} /* else */

return(ret);

} /* AU_read */

static int AU_rewind(Sound_Sample *sample)

{

Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;

struct audec *dec = (struct audec *) internal->decoder_private;

int rc = SDL_RWseek(internal->rw, dec->start_offset, SEEK_SET);

BAIL_IF_MACRO(rc != dec->start_offset, ERR_IO_ERROR, 0);

dec->remaining = dec->total;

return(1);

} /* AU_rewind */

static int AU_seek(Sound_Sample *sample, Uint32 ms)

{

Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;

struct audec *dec = (struct audec *) internal->decoder_private;

if (dec->encoding == AU_ENC_ULAW_8)

offset >>= 1; /* halve the byte offset for compression. */

pos = (int) (dec->start_offset + offset);

rc = SDL_RWseek(internal->rw, pos, SEEK_SET);

BAIL_IF_MACRO(rc != pos, ERR_IO_ERROR, 0);

dec->remaining = dec->total - offset;

} /* AU_seek */