/project/jni/sdl_sound/decoders/raw.c
https://github.com/aichunyu/FFPlayer · C · 184 lines · 89 code · 37 blank · 58 comment · 14 complexity · 244fabcf8c9622c3fa0b0bd9eaf50237 MD5 · raw file
- /*
- * 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@icculus.org)
- */
- #if HAVE_CONFIG_H
- # include <config.h>
- #endif
- #ifdef SOUND_SUPPORTS_RAW
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.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 int RAW_seek(Sound_Sample *sample, Uint32 ms);
- static const char *extensions_raw[] = { "RAW", NULL };
- const Sound_DecoderFunctions __Sound_DecoderFunctions_RAW =
- {
- {
- extensions_raw,
- "Raw audio",
- "Ryan C. Gordon <icculus@icculus.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 */
- RAW_seek /* seek() 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)
- BAIL_MACRO("RAW: extension isn't explicitly \"RAW\".", 0);
- /*
- * 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) )
- {
- BAIL_MACRO("RAW: invalid desired format.", 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_CANSEEK;
- 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 */
- static int RAW_seek(Sound_Sample *sample, Uint32 ms)
- {
- Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
- int pos = (int) __Sound_convertMsToBytePos(&sample->actual, ms);
- int err = (SDL_RWseek(internal->rw, pos, SEEK_SET) != pos);
- BAIL_IF_MACRO(err, ERR_IO_ERROR, 0);
- return(1);
- } /* RAW_seek */
- #endif /* SOUND_SUPPORTS_RAW */
- /* end of raw.c ... */