Mercurial > SDL_sound_CoreAudio
annotate decoders/raw.c @ 25:4acb5260d684
Made the SDL audio callback much more robust.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Wed, 19 Sep 2001 14:05:36 +0000 |
| parents | 29313c20963d |
| children | ea58bc3b15d7 |
| rev | line source |
|---|---|
| 4 | 1 /* |
| 2 * SDL_sound -- An abstract sound format decoding API. | |
| 3 * Copyright (C) 2001 Ryan C. Gordon. | |
| 4 * | |
| 5 * This library is free software; you can redistribute it and/or | |
| 6 * modify it under the terms of the GNU Lesser General Public | |
| 7 * License as published by the Free Software Foundation; either | |
| 8 * version 2.1 of the License, or (at your option) any later version. | |
| 9 * | |
| 10 * This library is distributed in the hope that it will be useful, | |
| 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 * Lesser General Public License for more details. | |
| 14 * | |
| 15 * You should have received a copy of the GNU Lesser General Public | |
| 16 * License along with this library; if not, write to the Free Software | |
| 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 */ | |
| 19 | |
| 20 /* | |
| 21 * RAW decoder for SDL_sound. This is as simple as it gets. | |
| 22 * | |
| 23 * This driver handles raw audio data. You must, regardless of where the | |
| 24 * data is actually coming from, specify the string "RAW" in the extension | |
| 25 * parameter of Sound_NewSample() (or, alternately, open a file with the | |
| 26 * extension ".raw" in Sound_NewSampleFromFile()). The string is checked | |
| 27 * case-insensitive. We need this check, because raw data, being raw, has | |
| 28 * no headers or magic number we can use to determine if we should handle a | |
| 29 * given file, so we needed some way to have this "decoder" discriminate. | |
| 30 * | |
| 31 * When calling Sound_NewSample*(), you must also specify a "desired" | |
| 32 * audio format. The "actual" format will always match what you specify, so | |
| 33 * there will be no conversion overhead, but these routines need to know how | |
| 34 * to treat the bits, since it's all random garbage otherwise. | |
| 35 * | |
| 36 * Please see the file LICENSE in the source's root directory. | |
| 37 * | |
| 38 * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) | |
| 39 */ | |
| 40 | |
| 41 #include <stdio.h> | |
| 42 #include <stdlib.h> | |
| 43 #include <string.h> | |
| 44 #include <assert.h> | |
| 45 #include "SDL_sound.h" | |
| 46 | |
| 47 #define __SDL_SOUND_INTERNAL__ | |
| 48 #include "SDL_sound_internal.h" | |
| 49 | |
| 50 #if (!defined SOUND_SUPPORTS_RAW) | |
| 51 #error SOUND_SUPPORTS_RAW must be defined. | |
| 52 #endif | |
| 53 | |
| 54 | |
| 55 static int RAW_open(Sound_Sample *sample, const char *ext); | |
| 56 static void RAW_close(Sound_Sample *sample); | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
57 static Uint32 RAW_read(Sound_Sample *sample); |
| 4 | 58 |
| 59 const Sound_DecoderFunctions __Sound_DecoderFunctions_RAW = | |
| 60 { | |
| 61 { | |
| 62 "RAW", | |
| 63 "Raw audio", | |
| 64 "Ryan C. Gordon <icculus@clutteredmind.org>", | |
| 65 "http://www.icculus.org/SDL_sound/" | |
| 66 }, | |
| 67 | |
| 68 RAW_open, /* open() method */ | |
| 69 RAW_close, /* close() method */ | |
| 70 RAW_read /* read() method */ | |
| 71 }; | |
| 72 | |
| 73 | |
| 74 static int RAW_open(Sound_Sample *sample, const char *ext) | |
| 75 { | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
76 /* |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
77 * We check this explicitly, since we have no other way to |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
78 * determine whether we should handle this data or not. |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
79 */ |
| 4 | 80 if (__Sound_strcasecmp(ext, "RAW") != 0) |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
81 { |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
82 Sound_SetError("RAW: extension isn't explicitly \"RAW\"."); |
| 4 | 83 return(0); |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
84 } /* if */ |
| 4 | 85 |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
86 /* |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
87 * You must also specify a desired format, so we know how to |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
88 * treat the bits that are otherwise binary garbage. |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
89 */ |
| 4 | 90 if ( (sample->desired.channels < 1) || |
| 91 (sample->desired.channels > 2) || | |
| 92 (sample->desired.rate == 0) || | |
| 93 (sample->desired.format == 0) ) | |
| 94 { | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
95 Sound_SetError("RAW: invalid desired format."); |
| 4 | 96 return(0); |
| 97 } /* if */ | |
| 98 | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
99 _D(("RAW: Accepting data stream.\n")); |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
100 |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
101 /* |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
102 * We never convert raw samples; what you ask for is what you get. |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
103 */ |
| 4 | 104 memcpy(&sample->actual, &sample->desired, sizeof (Sound_AudioInfo)); |
| 105 sample->flags = SOUND_SAMPLEFLAG_NONE; | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
106 |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
107 return(1); /* we'll handle this data. */ |
| 4 | 108 } /* RAW_open */ |
| 109 | |
| 110 | |
| 111 static void RAW_close(Sound_Sample *sample) | |
| 112 { | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
113 /* we don't allocate anything that we need to free. That's easy, eh? */ |
| 4 | 114 } /* RAW_close */ |
| 115 | |
| 116 | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
117 static Uint32 RAW_read(Sound_Sample *sample) |
| 4 | 118 { |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
119 Uint32 retval; |
| 4 | 120 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
121 |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
122 /* |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
123 * We don't actually do any decoding, so we read the raw data |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
124 * directly into the internal buffer... |
|
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
125 */ |
| 4 | 126 retval = SDL_RWread(internal->rw, internal->buffer, |
| 127 1, internal->buffer_size); | |
| 128 | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
129 /* Make sure the read went smoothly... */ |
| 4 | 130 if (retval == 0) |
| 131 sample->flags |= SOUND_SAMPLEFLAG_EOF; | |
| 132 | |
| 133 else if (retval == -1) | |
| 134 sample->flags |= SOUND_SAMPLEFLAG_ERROR; | |
| 135 | |
|
7
29313c20963d
Updated a lot of comments, and changed read() method's return type.
Ryan C. Gordon <icculus@icculus.org>
parents:
4
diff
changeset
|
136 /* (next call this EAGAIN may turn into an EOF or error.) */ |
| 4 | 137 else if (retval < internal->buffer_size) |
| 138 sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; | |
| 139 | |
| 140 return(retval); | |
| 141 } /* RAW_read */ | |
| 142 | |
| 143 | |
| 144 /* end of raw.c ... */ | |
| 145 |