SDL_mixer: load_aiff.c@695494546b3c (annotated)

slouken@111	1	/*
slouken@111	2	SDL_mixer: An audio mixer library based on the SDL library
slouken@386	3	Copyright (C) 1997-2009 Sam Lantinga
slouken@111	4
slouken@111	5	This library is free software; you can redistribute it and/or
slouken@111	6	modify it under the terms of the GNU Library General Public
slouken@111	7	License as published by the Free Software Foundation; either
slouken@111	8	version 2 of the License, or (at your option) any later version.
slouken@111	9
slouken@111	10	This library is distributed in the hope that it will be useful,
slouken@111	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
slouken@111	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
slouken@111	13	Library General Public License for more details.
slouken@111	14
slouken@111	15	You should have received a copy of the GNU Library General Public
slouken@111	16	License along with this library; if not, write to the Free
slouken@111	17	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
slouken@111	18
slouken@111	19	This is the source needed to decode an AIFF file into a waveform.
slouken@111	20	It's pretty straightforward once you get going. The only
slouken@111	21	externally-callable function is Mix_LoadAIFF_RW(), which is meant to
slouken@111	22	act as identically to SDL_LoadWAV_RW() as possible.
slouken@111	23
slouken@111	24	This file by Torbj�rn Andersson (torbjorn.andersson@eurotime.se)
slouken@216	25	8SVX file support added by Marc Le Douarain (mavati@club-internet.fr)
slouken@216	26	in december 2002.
slouken@111	27	*/
slouken@111	28
slouken@140	29	/* $Id$ */
slouken@138	30
slouken@142	31	#include <stdlib.h>
slouken@114	32	#include <string.h>
slouken@111	33
slouken@142	34	#include "SDL_endian.h"
slouken@111	35	#include "SDL_mixer.h"
slouken@111	36	#include "load_aiff.h"
slouken@111	37
slouken@111	38	/*********************************************/
slouken@111	39	/* Define values for AIFF (IFF audio) format */
slouken@111	40	/*********************************************/
slouken@111	41	#define FORM 0x4d524f46 /* "FORM" */
slouken@216	42
slouken@111	43	#define AIFF 0x46464941 /* "AIFF" */
slouken@111	44	#define SSND 0x444e5353 /* "SSND" */
slouken@111	45	#define COMM 0x4d4d4f43 /* "COMM" */
slouken@111	46
slouken@216	47	#define _8SVX 0x58565338 /* "8SVX" */
slouken@216	48	#define VHDR 0x52444856 /* "VHDR" */
slouken@216	49	#define BODY 0x59444F42 /* "BODY" */
slouken@216	50
slouken@111	51	/* This function was taken from libsndfile. I don't pretend to fully
slouken@111	52	* understand it.
slouken@111	53	*/
slouken@111	54
slouken@111	55	static Uint32 SANE_to_Uint32 (Uint8 *sanebuf)
slouken@111	56	{
slouken@111	57	/* Is the frequency outside of what we can represent with Uint32? */
slouken@111	58	if ( (sanebuf[0] & 0x80) \|\| (sanebuf[0] <= 0x3F) \|\| (sanebuf[0] > 0x40)
slouken@111	59	\|\| (sanebuf[0] == 0x40 && sanebuf[1] > 0x1C) )
slouken@111	60	return 0;
slouken@111	61
slouken@111	62	return ((sanebuf[2] << 23) \| (sanebuf[3] << 15) \| (sanebuf[4] << 7)
slouken@111	63	\| (sanebuf[5] >> 1)) >> (29 - sanebuf[1]);
slouken@111	64	}
slouken@111	65
slouken@111	66	/* This function is based on SDL_LoadWAV_RW(). */
slouken@111	67
slouken@111	68	SDL_AudioSpec Mix_LoadAIFF_RW (SDL_RWops src, int freesrc,
slouken@111	69	SDL_AudioSpec spec, Uint8 audio_buf, Uint32 audio_len)
slouken@111	70	{
slouken@111	71	int was_error;
slouken@111	72	int found_SSND;
slouken@111	73	int found_COMM;
slouken@216	74	int found_VHDR;
slouken@216	75	int found_BODY;
slouken@142	76	long start = 0;
slouken@111	77
slouken@111	78	Uint32 chunk_type;
slouken@111	79	Uint32 chunk_length;
slouken@111	80	long next_chunk;
slouken@111	81
slouken@111	82	/* AIFF magic header */
slouken@111	83	Uint32 FORMchunk;
slouken@111	84	Uint32 AIFFmagic;
slouken@111	85
slouken@111	86	/* SSND chunk */
slouken@111	87	Uint32 offset;
slouken@111	88	Uint32 blocksize;
slouken@111	89
slouken@111	90	/* COMM format chunk */
slouken@142	91	Uint16 channels = 0;
slouken@142	92	Uint32 numsamples = 0;
slouken@142	93	Uint16 samplesize = 0;
slouken@111	94	Uint8 sane_freq[10];
slouken@142	95	Uint32 frequency = 0;
slouken@111	96
slouken@111	97	/* Make sure we are passed a valid data source */
slouken@111	98	was_error = 0;
slouken@111	99	if ( src == NULL ) {
slouken@111	100	was_error = 1;
slouken@111	101	goto done;
slouken@111	102	}
slouken@111	103
slouken@111	104	FORMchunk = SDL_ReadLE32(src);
slouken@111	105	chunk_length = SDL_ReadBE32(src);
slouken@111	106	if ( chunk_length == AIFF ) { /* The FORMchunk has already been read */
slouken@111	107	AIFFmagic = chunk_length;
slouken@111	108	chunk_length = FORMchunk;
slouken@111	109	FORMchunk = FORM;
slouken@111	110	} else {
slouken@111	111	AIFFmagic = SDL_ReadLE32(src);
slouken@111	112	}
slouken@216	113	if ( (FORMchunk != FORM) \|\| ( (AIFFmagic != AIFF) && (AIFFmagic != _8SVX) ) ) {
slouken@216	114	SDL_SetError("Unrecognized file type (not AIFF nor 8SVX)");
slouken@111	115	was_error = 1;
slouken@111	116	goto done;
slouken@111	117	}
slouken@111	118
slouken@111	119	/* TODO: Better santity-checking. */
slouken@111	120
slouken@111	121	found_SSND = 0;
slouken@111	122	found_COMM = 0;
slouken@216	123	found_VHDR = 0;
slouken@216	124	found_BODY = 0;
slouken@111	125
slouken@111	126	do {
slouken@111	127	chunk_type = SDL_ReadLE32(src);
slouken@111	128	chunk_length = SDL_ReadBE32(src);
slouken@111	129	next_chunk = SDL_RWtell(src) + chunk_length;
slouken@111	130	/* Paranoia to avoid infinite loops */
slouken@111	131	if (chunk_length == 0)
slouken@111	132	break;
slouken@111	133
slouken@111	134	switch (chunk_type) {
slouken@111	135	case SSND:
slouken@111	136	found_SSND = 1;
slouken@111	137	offset = SDL_ReadBE32(src);
slouken@111	138	blocksize = SDL_ReadBE32(src);
slouken@111	139	start = SDL_RWtell(src) + offset;
slouken@111	140	break;
slouken@111	141
slouken@111	142	case COMM:
slouken@111	143	found_COMM = 1;
slouken@111	144	channels = SDL_ReadBE16(src);
slouken@111	145	numsamples = SDL_ReadBE32(src);
slouken@111	146	samplesize = SDL_ReadBE16(src);
slouken@111	147	SDL_RWread(src, sane_freq, sizeof(sane_freq), 1);
slouken@111	148	frequency = SANE_to_Uint32(sane_freq);
slouken@111	149	if (frequency == 0) {
slouken@111	150	SDL_SetError("Bad AIFF sample frequency");
slouken@111	151	was_error = 1;
slouken@111	152	goto done;
slouken@111	153	}
slouken@111	154	break;
slouken@111	155
slouken@216	156	case VHDR:
slouken@216	157	found_VHDR = 1;
slouken@216	158	SDL_ReadBE32(src);
slouken@216	159	SDL_ReadBE32(src);
slouken@216	160	SDL_ReadBE32(src);
slouken@216	161	frequency = SDL_ReadBE16(src);
slouken@216	162	channels = 1;
slouken@216	163	samplesize = 8;
slouken@216	164	break;
slouken@216	165
slouken@216	166	case BODY:
slouken@216	167	found_BODY = 1;
slouken@216	168	numsamples = chunk_length;
slouken@216	169	start = SDL_RWtell(src);
slouken@216	170	break;
slouken@216	171
slouken@111	172	default:
slouken@111	173	break;
slouken@111	174	}
slouken@216	175	/* a 0 pad byte can be stored for any odd-length chunk */
slouken@216	176	if (chunk_length&1)
slouken@216	177	next_chunk++;
slouken@216	178	} while ( ( ( (AIFFmagic == AIFF) && ( !found_SSND \|\| !found_COMM ) )
slouken@216	179	\|\| ( (AIFFmagic == _8SVX ) && ( !found_VHDR \|\| !found_BODY ) ) )
slouken@111	180	&& SDL_RWseek(src, next_chunk, SEEK_SET) != 1 );
slouken@111	181
slouken@216	182	if ( (AIFFmagic == AIFF) && !found_SSND ) {
slouken@111	183	SDL_SetError("Bad AIFF (no SSND chunk)");
slouken@111	184	was_error = 1;
slouken@111	185	goto done;
slouken@111	186	}
slouken@111	187
slouken@216	188	if ( (AIFFmagic == AIFF) && !found_COMM ) {
slouken@111	189	SDL_SetError("Bad AIFF (no COMM chunk)");
slouken@111	190	was_error = 1;
slouken@111	191	goto done;
slouken@111	192	}
slouken@111	193
slouken@216	194	if ( (AIFFmagic == _8SVX) && !found_VHDR ) {
slouken@216	195	SDL_SetError("Bad 8SVX (no VHDR chunk)");
slouken@216	196	was_error = 1;
slouken@216	197	goto done;
slouken@216	198	}
slouken@216	199
slouken@216	200	if ( (AIFFmagic == _8SVX) && !found_BODY ) {
slouken@216	201	SDL_SetError("Bad 8SVX (no BODY chunk)");
slouken@216	202	was_error = 1;
slouken@216	203	goto done;
slouken@216	204	}
slouken@216	205
slouken@111	206	/* Decode the audio data format */
slouken@111	207	memset(spec, 0, sizeof(*spec));
slouken@111	208	spec->freq = frequency;
slouken@111	209	switch (samplesize) {
slouken@111	210	case 8:
slouken@111	211	spec->format = AUDIO_S8;
slouken@111	212	break;
slouken@111	213	case 16:
slouken@111	214	spec->format = AUDIO_S16MSB;
slouken@111	215	break;
slouken@111	216	default:
slouken@111	217	SDL_SetError("Unsupported AIFF samplesize");
slouken@111	218	was_error = 1;
slouken@111	219	goto done;
slouken@111	220	}
slouken@111	221	spec->channels = (Uint8) channels;
slouken@111	222	spec->samples = 4096; /* Good default buffer size */
slouken@111	223
slouken@111	224	audio_len = channels numsamples * (samplesize / 8);
slouken@111	225	audio_buf = (Uint8 )malloc(*audio_len);
slouken@111	226	if ( *audio_buf == NULL ) {
slouken@111	227	SDL_SetError("Out of memory");
slouken@111	228	return(NULL);
slouken@111	229	}
slouken@111	230	SDL_RWseek(src, start, SEEK_SET);
slouken@111	231	if ( SDL_RWread(src, audio_buf, audio_len, 1) != 1 ) {
slouken@111	232	SDL_SetError("Unable to read audio data");
slouken@111	233	return(NULL);
slouken@111	234	}
slouken@111	235
slouken@111	236	/* Don't return a buffer that isn't a multiple of samplesize */
slouken@111	237	*audio_len &= ~((samplesize / 8) - 1);
slouken@111	238
slouken@111	239	done:
slouken@111	240	if ( freesrc && src ) {
slouken@111	241	SDL_RWclose(src);
slouken@111	242	}
slouken@111	243	if ( was_error ) {
slouken@111	244	spec = NULL;
slouken@111	245	}
slouken@111	246	return(spec);
slouken@111	247	}
slouken@216	248

author	Sam Lantinga <slouken@libsdl.org>
	Mon, 08 Dec 2008 00:27:32 +0000
changeset 386	695494546b3c
parent 241	503416fca921
child 473	60b7e1c4f6b2
permissions	-rw-r--r--