annotate docs/man3/SDL_AudioCVT.3 @ 172:37e3ca9254c7

Date: Sat, 8 Sep 2001 04:42:23 +0200 From: Max Horn <max@quendi.de> Subject: SDL/OSX: Joystick; Better key handling I just finished implementing improved keyhandling for OS X (in fact the code should be easily ported to the "normal" MacOS part of SDL, I just had no chance yet). Works like this: First init the mapping table statically like before. Them, it queries the OS for the "official" key table, then iterates over all 127 scancode and gets the associates ascii code. It ignores everythng below 32 (has to, as it would lead to many problems if we did not... e.g. both ESC and NUM LOCk produce an ascii code 27 on my keyboard), and all stuff above 127 is mapped to SDLK_WORLD_* simply in the order it is encountered. In addition, caps lock is now working, too. The code work flawless for me, but since I only have one keyboard, I may have not encountered some serious problem... but I am pretty confident that it is better than the old code in most cases. The joystick driver works fine for me, too. I think it can be added to CVS already. It would simply be helpful if more people would test it. Hm, I wonder if Maelstrom or GLTron has Joystick support? That would be a wonderful test application :) I also took the liberty of modifying some text files like BUGS, README.CVS, README.MacOSX (which now contains the OS X docs I long promised)
author Sam Lantinga <slouken@libsdl.org>
date Tue, 11 Sep 2001 19:00:18 +0000
parents 55f1f1b3e27d
children e5bc29de3f0a
rev   line source
55
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
1 .TH "SDL_AudioCVT" "3" "Sun 10 Jun 2001, 19:40" "SDL" "SDL API Reference"
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
2 .SH "NAME"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
3 SDL_AudioCVT\- Audio Conversion Structure
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
4 .SH "STRUCTURE DEFINITION"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
5 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
6 .nf
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
7 \f(CWtypedef struct{
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
8 int needed;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
9 Uint16 src_format;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
10 Uint16 dest_format;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
11 double rate_incr;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
12 Uint8 *buf;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
13 int len;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
14 int len_cvt;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
15 int len_mult;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
16 double len_ratio;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
17 void (*filters[10])(struct SDL_AudioCVT *cvt, Uint16 format);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
18 int filter_index;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
19 } SDL_AudioCVT;\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
20 .fi
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
21 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
22 .SH "STRUCTURE DATA"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
23 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
24 \fBneeded\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
25 Set to one if the conversion is possible
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
26 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
27 \fBsrc_format\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
28 Audio format of the source
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
29 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
30 \fBdest_format\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
31 Audio format of the destination
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
32 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
33 \fBrate_incr\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
34 Rate conversion increment
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
35 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
36 \fBbuf\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
37 Audio buffer
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
38 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
39 \fBlen\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
40 Length of the original audio buffer in bytes
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
41 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
42 \fBlen_cvt\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
43 Length of converted audio buffer in bytes (calculated)
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
44 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
45 \fBlen_mult\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
46 \fBbuf\fR must be \fBlen\fR*\fBlen_mult\fR bytes in size(calculated)
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
47 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
48 \fBlen_ratio\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
49 Final audio size is \fBlen\fR*\fBlen_ratio\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
50 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
51 \fBfilters[10](\&.\&.)\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
52 Pointers to functions needed for this conversion
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
53 .TP 20
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
54 \fBfilter_index\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
55 Current conversion function
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
56 .SH "DESCRIPTION"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
57 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
58 The \fBSDL_AudioCVT\fR is used to convert audio data between different formats\&. A \fBSDL_AudioCVT\fR structure is created with the \fI\fBSDL_BuildAudioCVT\fP\fR function, while the actual conversion is done by the \fI\fBSDL_ConvertAudio\fP\fR function\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
59 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
60 Many of the fields in the \fBSDL_AudioCVT\fR structure should be considered private and their function will not be discussed here\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
61 .IP "\fBUint8 *\fP\fBbuf\fR" 10This points to the audio data that will be used in the conversion\&. It is both the source and the destination, which means the converted audio data overwrites the original data\&. It also means that the converted data may be larger than the original data (if you were converting from 8-bit to 16-bit, for instance), so you must ensure \fBbuf\fR is large enough\&. See below\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
62 .IP "\fBint\fP \fBlen\fR" 10This is the length of the original audio data in bytes\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
63 .IP "\fBint\fP \fBlen_mult\fR" 10As explained above, the audio buffer needs to be big enough to store the converted data, which may be bigger than the original audio data\&. The length of \fBbuf\fR should be \fBlen\fR*\fBlen_mult\fR\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
64 .IP "\fBdouble\fP \fBlen_ratio\fR" 10When you have finished converting your audio data, you need to know how much of your audio buffer is valid\&. \fBlen\fR*\fBlen_ratio\fR is the size of the converted audio data in bytes\&. This is very similar to \fBlen_mult\fR, however when the convert audio data is shorter than the original \fBlen_mult\fR would be 1\&. \fBlen_ratio\fR, on the other hand, would be a fractional number between 0 and 1\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
65 .SH "SEE ALSO"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
66 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
67 \fI\fBSDL_BuildAudioCVT\fP\fR, \fI\fBSDL_ConvertAudio\fP\fR, \fI\fBSDL_AudioSpec\fR\fR
55
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
68 ...\" created by instant / docbook-to-man, Sun 10 Jun 2001, 19:40