Mercurial > SDL_sound_CoreAudio
annotate decoders/skeleton.c @ 474:c66080364dff
Most decoders now report total sample play time, now. Technically, this
breaks binary compatibility with the 1.0 branch, since it extends the
Sound_Sample struct, but most (all?) programs are just passing pointers
allocated by SDL_sound around, and might be okay.
Source-level compatibility is not broken...yet! :)
--ryan.
-------- Original Message --------
Subject: SDL_sound patch: Finding total length of time of sound file.
Date: Sun, 26 Jan 2003 09:31:17 -0800 (PST)
Hi Ryan,
I am working with Eric Wing and helping him modify
SDL_sound. AS part of our efforts in improving and
enhancing SDL_sound, we like to submit this patch. We
modified the codecs to find the total time of a sound
file. Below is the explanation of the patch. The
patch is appended as an attachment to this email.
* MOTIVATION:
We needed the ability to get the total play time of a
sample (And we noticed that we're not the only ones).
Since SDL_sound blocks direct access to the specific
decoders, there is no way for a user to know this
information short of decoding the whole thing.
Because of this, we believe this will be a useful
addition, even though the accuracy may not be perfect
(subject to each decoder) or the information may not
always be available.
* CONTRIBUTORS:
Wesley Leong (modified the majority of the codecs and
verified the results)
Eric Wing (showed everyone how to do modify codec,
modified mikmod)
Wang Lam (modified a handful of codecs, researched
into specs and int overflow)
Ahilan Anantha (modified a few codecs and helped with
integer math)
* GENERAL ISSUES:
We chose the value to be milliseconds as an Sint32.
Milliseconds because that's what Sound_Seek takes as a
parameter and -1 to allow for instances/codecs where
the value could not be determined. We are
not sure if this is the final convention you want, so
we are willing to work with you on this.
We also expect the total_time field to be set on open
and never again modified by SDL_sound. Users may
access it directly much like the sample buffer and
buffer_size. We thought about recomputing the time
on DecodeAll, but since users may seek or decode small
chunks first, not all the data may be there. So this
is better done by the user. This may be good
information to document.
Currently, all the main codecs are implemented except
for QuickTime.
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Sat, 08 May 2004 08:19:50 +0000 |
parents | fb519e6028e3 |
children | 50bb9a6cebfe |
rev | line source |
---|---|
16 | 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 * FMT decoder for SDL_sound. | |
22 * | |
23 * This driver handles FMT audio data. Blahblahblah... The author should | |
24 * have done a search and replace on "fmt" and "FMT" and changed this | |
25 * comment. This is the default comment in the skeleton decoder file... | |
26 * | |
221
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
27 * None of this code, even the parts that LOOK right, have been compiled, |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
28 * so you cut-and-paste at your own risk. |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
29 * |
184
47cc2de2ae36
Changed reference to "LICENSE" file to "COPYING".
Ryan C. Gordon <icculus@icculus.org>
parents:
149
diff
changeset
|
30 * Please see the file COPYING in the source's root directory. |
16 | 31 * |
32 * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) | |
33 */ | |
34 | |
103
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
35 #error DO NOT COMPILE THIS. |
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
36 #error This is an example decoder skeleton. |
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
37 #error You should base your code on this file, and remove these error lines |
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
38 #error from your version. |
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
39 |
106
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
40 #if HAVE_CONFIG_H |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
41 # include <config.h> |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
42 #endif |
100
6d9fdec2f708
added config.h, added --enable-debug flag, various other changes to the build system
fingolfin
parents:
64
diff
changeset
|
43 |
103
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
44 #ifdef SOUND_SUPPORTS_FMT |
706ec5842737
Updated for autoconf change, and placed #error messages so people don't
Ryan C. Gordon <icculus@icculus.org>
parents:
100
diff
changeset
|
45 |
16 | 46 #include <stdio.h> |
47 #include <stdlib.h> | |
48 #include <string.h> | |
49 | |
106
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
50 #include "SDL_sound.h" |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
51 |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
52 #define __SDL_SOUND_INTERNAL__ |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
53 #include "SDL_sound_internal.h" |
40de367eb59e
Changing my include structure to do this right.
Ryan C. Gordon <icculus@icculus.org>
parents:
103
diff
changeset
|
54 |
47
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
55 static int FMT_init(void); |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
56 static void FMT_quit(void); |
16 | 57 static int FMT_open(Sound_Sample *sample, const char *ext); |
58 static void FMT_close(Sound_Sample *sample); | |
59 static Uint32 FMT_read(Sound_Sample *sample); | |
221
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
60 static int FMT_rewind(Sound_Sample *sample); |
306
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
61 static int FMT_seek(Sound_Sample *sample, Uint32 ms); |
16 | 62 |
149
1df5c106504e
Decoders can now list multiple file extensions.
Ryan C. Gordon <icculus@icculus.org>
parents:
106
diff
changeset
|
63 static const char *extensions_fmt[] = { "FMT", NULL }; |
16 | 64 const Sound_DecoderFunctions __Sound_DecoderFunctions_FMT = |
65 { | |
66 { | |
149
1df5c106504e
Decoders can now list multiple file extensions.
Ryan C. Gordon <icculus@icculus.org>
parents:
106
diff
changeset
|
67 extensions_fmt, |
16 | 68 "FMT audio format description", |
69 "Ryan C. Gordon <icculus@clutteredmind.org>", | |
70 "http://www.icculus.org/SDL_sound/" | |
71 }, | |
72 | |
221
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
73 FMT_init, /* init() method */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
74 FMT_quit, /* quit() method */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
75 FMT_open, /* open() method */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
76 FMT_close, /* close() method */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
77 FMT_read, /* read() method */ |
306
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
78 FMT_rewind, /* rewind() method */ |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
79 FMT_seek /* seek() method */ |
16 | 80 }; |
81 | |
82 | |
47
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
83 static int FMT_init(void) |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
84 { |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
85 /* do any global decoder/library initialization you need here. */ |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
86 |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
87 return(1); /* initialization successful. */ |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
88 } /* FMT_init */ |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
89 |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
90 |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
91 static void FMT_quit(void) |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
92 { |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
93 /* do any global decoder/library cleanup you need here. */ |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
94 } /* FMT_quit */ |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
95 |
ea58bc3b15d7
Added init() and quit() methods.
Ryan C. Gordon <icculus@icculus.org>
parents:
21
diff
changeset
|
96 |
16 | 97 static int FMT_open(Sound_Sample *sample, const char *ext) |
98 { | |
21
d9b9d60cf9a9
Added some helpful info to FMT_open()...
Ryan C. Gordon <icculus@icculus.org>
parents:
16
diff
changeset
|
99 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; |
d9b9d60cf9a9
Added some helpful info to FMT_open()...
Ryan C. Gordon <icculus@icculus.org>
parents:
16
diff
changeset
|
100 SDL_RWops *rw = internal->rw; |
d9b9d60cf9a9
Added some helpful info to FMT_open()...
Ryan C. Gordon <icculus@icculus.org>
parents:
16
diff
changeset
|
101 |
16 | 102 if (can NOT accept the data) |
387
fb519e6028e3
Changed all the Sound_SetError() calls to __Sound_SetError (or BAIL*_MACRO)
Ryan C. Gordon <icculus@icculus.org>
parents:
377
diff
changeset
|
103 BAIL_MACRO("FMT: expected X, got Y.", 0); |
16 | 104 |
62
b13fafb976be
Changed _D macro to DBGSND.
Ryan C. Gordon <icculus@icculus.org>
parents:
47
diff
changeset
|
105 SNDDBG(("FMT: Accepting data stream.\n")); |
16 | 106 set up sample->actual; |
107 sample->flags = SOUND_SAMPLEFLAG_NONE; | |
108 return(1); /* we'll handle this data. */ | |
109 } /* FMT_open */ | |
110 | |
111 | |
112 static void FMT_close(Sound_Sample *sample) | |
113 { | |
114 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
115 clean up anything you put into internal->decoder_private; | |
116 } /* FMT_close */ | |
117 | |
118 | |
119 static Uint32 FMT_read(Sound_Sample *sample) | |
120 { | |
121 Uint32 retval; | |
122 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; | |
123 | |
124 /* | |
125 * We don't actually do any decoding, so we read the fmt data | |
126 * directly into the internal buffer... | |
127 */ | |
128 retval = SDL_RWread(internal->rw, internal->buffer, | |
129 1, internal->buffer_size); | |
130 | |
131 (or whatever. Do some decoding here...) | |
132 | |
133 /* Make sure the read went smoothly... */ | |
134 if (retval == 0) | |
135 sample->flags |= SOUND_SAMPLEFLAG_EOF; | |
136 | |
137 else if (retval == -1) | |
138 sample->flags |= SOUND_SAMPLEFLAG_ERROR; | |
139 | |
140 /* (next call this EAGAIN may turn into an EOF or error.) */ | |
141 else if (retval < internal->buffer_size) | |
142 sample->flags |= SOUND_SAMPLEFLAG_EAGAIN; | |
143 | |
144 (or whatever. retval == number of bytes you put in internal->buffer). | |
145 | |
146 return(retval); | |
147 } /* FMT_read */ | |
148 | |
221
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
149 |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
150 static int FMT_rewind(Sound_Sample *sample) |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
151 { |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
152 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
153 |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
154 /* seek to the appropriate place... */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
155 BAIL_IF_MACRO(SDL_RWseek(internal->rw, 0, SEEK_SET) != 0, ERR_IO_ERROR, 0); |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
156 |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
157 (reset state as necessary.) |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
158 |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
159 return(1); /* success. */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
160 } /* FMT_rewind */ |
c9772a9f5271
Initial implementation or stubs for rewind method. Other cleanups.
Ryan C. Gordon <icculus@icculus.org>
parents:
184
diff
changeset
|
161 |
306
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
162 |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
163 static int FMT_seek(Sound_Sample *sample, Uint32 ms) |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
164 { |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
165 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
166 |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
167 /* seek to the appropriate place... */ |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
168 BAIL_IF_MACRO(SDL_RWseek(internal->rw, 0, SEEK_SET) != 0, ERR_IO_ERROR, 0); |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
169 |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
170 (set state as necessary.) |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
171 |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
172 return(1); /* success. */ |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
173 } /* FMT_seek */ |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
174 |
c97be6e1bd27
Added framework for Sound_Seek() support.
Ryan C. Gordon <icculus@icculus.org>
parents:
221
diff
changeset
|
175 |
64
40006625142a
Changes in preparation of autoconf support.
Ryan C. Gordon <icculus@icculus.org>
parents:
62
diff
changeset
|
176 #endif /* SOUND_SUPPORTS_FMT */ |
40006625142a
Changes in preparation of autoconf support.
Ryan C. Gordon <icculus@icculus.org>
parents:
62
diff
changeset
|
177 |
16 | 178 |
179 /* end of fmt.c ... */ | |
180 |