Mercurial > SDL_sound_CoreAudio
view decoders/raw.c @ 304:0cf2b2e4a259
Updated.
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Sun, 21 Apr 2002 17:47:52 +0000 |
parents | c9772a9f5271 |
children | c97be6e1bd27 |
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/* * 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 */ /* * RAW decoder for SDL_sound. This is as simple as it gets. * * This driver handles raw audio data. You must, regardless of where the * data is actually coming from, specify the string "RAW" in the extension * parameter of Sound_NewSample() (or, alternately, open a file with the * extension ".raw" in Sound_NewSampleFromFile()). The string is checked * case-insensitive. We need this check, because raw data, being raw, has * no headers or magic number we can use to determine if we should handle a * given file, so we needed some way to have this "decoder" discriminate. * * When calling Sound_NewSample*(), you must also specify a "desired" * audio format. The "actual" format will always match what you specify, so * there will be no conversion overhead, but these routines need to know how * to treat the bits, since it's all random garbage otherwise. * * Please see the file COPYING in the source's root directory. * * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) */ #if HAVE_CONFIG_H # include <config.h> #endif #ifdef SOUND_SUPPORTS_RAW #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include "SDL_sound.h" #define __SDL_SOUND_INTERNAL__ #include "SDL_sound_internal.h" static int RAW_init(void); static void RAW_quit(void); static int RAW_open(Sound_Sample *sample, const char *ext); static void RAW_close(Sound_Sample *sample); static Uint32 RAW_read(Sound_Sample *sample); static int RAW_rewind(Sound_Sample *sample); static const char *extensions_raw[] = { "RAW", NULL }; const Sound_DecoderFunctions __Sound_DecoderFunctions_RAW = { { extensions_raw, "Raw audio", "Ryan C. Gordon <icculus@clutteredmind.org>", "http://www.icculus.org/SDL_sound/" }, RAW_init, /* init() method */ RAW_quit, /* quit() method */ RAW_open, /* open() method */ RAW_close, /* close() method */ RAW_read, /* read() method */ RAW_rewind /* rewind() method */ }; static int RAW_init(void) { return(1); /* always succeeds. */ } /* RAW_init */ static void RAW_quit(void) { /* it's a no-op. */ } /* RAW_quit */ static int RAW_open(Sound_Sample *sample, const char *ext) { /* * We check this explicitly, since we have no other way to * determine whether we should handle this data or not. */ if (__Sound_strcasecmp(ext, "RAW") != 0) { Sound_SetError("RAW: extension isn't explicitly \"RAW\"."); return(0); } /* if */ /* * You must also specify a desired format, so we know how to * treat the bits that are otherwise binary garbage. */ if ( (sample->desired.channels < 1) || (sample->desired.channels > 2) || (sample->desired.rate == 0) || (sample->desired.format == 0) ) { Sound_SetError("RAW: invalid desired format."); return(0); } /* if */ SNDDBG(("RAW: Accepting data stream.\n")); /* * We never convert raw samples; what you ask for is what you get. */ memcpy(&sample->actual, &sample->desired, sizeof (Sound_AudioInfo)); sample->flags = SOUND_SAMPLEFLAG_NONE; return(1); /* we'll handle this data. */ } /* RAW_open */ static void RAW_close(Sound_Sample *sample) { /* we don't allocate anything that we need to free. That's easy, eh? */ } /* RAW_close */ static Uint32 RAW_read(Sound_Sample *sample) { Uint32 retval; Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; /* * We don't actually do any decoding, so we read the raw data * directly into the internal buffer... */ retval = SDL_RWread(internal->rw, internal->buffer, 1, internal->buffer_size); /* Make sure the read went smoothly... */ if (retval == 0) sample->flags |= SOUND_SAMPLEFLAG_EOF; else if (retval == -1) sample->flags |= SOUND_SAMPLEFLAG_ERROR; /* (next call this EAGAIN may turn into an EOF or error.) */ else if (retval < internal->buffer_size) sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; return(retval); } /* RAW_read */ static int RAW_rewind(Sound_Sample *sample) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; BAIL_IF_MACRO(SDL_RWseek(internal->rw, 0, SEEK_SET) != 0, ERR_IO_ERROR, 0); return(1); } /* RAW_rewind */ #endif /* SOUND_SUPPORTS_RAW */ /* end of raw.c ... */