Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_AudioCVT.3 @ 3097:0d12e8f1de3c
Date: Thu, 05 Feb 2009 18:07:35 +0100
From: Stefan Klug
Subject: [SDL] SDL 1.3 WinCE backend
as promised, I've started to work on the WinCE backend of SDL 1.3
I've modified the win32 video backend and the gdi renderer, to work
properly in WinCE.
The results till now are great, but there is still some work to do.
Attached are two patches with my changes.
I would be happy if someone could review and propably commit them.
The first one (configure.in.patch) should be straight forward without
any side effects.
The second one does the necessary changes to the win32 backend. I was
really unhappy to start slicing this shiny new backend with
#ifdef/#endif but I saw no other option.
The most problematic issues are:
- WinCe has no GetDIBits, so its practically impossible to fill a
BITMAPINFO with correct values. I therefore removed the bmi member from
the GDI_RenderData in SDL_gdirender.c to prevent usage of a not or not
properly initialized bmi.
- In SDL_win32window.c I exchanged some ASCII function by their general
counterparts, (In CE only the Unicode versions are available). I don't
know if this has a negative effect when running in win32
Cheers
Stefan
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 23 Mar 2009 05:35:21 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| rev | line source |
|---|---|
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_AudioCVT" "3" "Tue 11 Sep 2001, 22:58" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
|
2283
546f7c1eb755
Merged revision 3472 from SDL 1.2, fixing bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
3 SDL_AudioCVT \- Audio Conversion Structure |
| 0 | 4 .SH "STRUCTURE DEFINITION" |
| 5 .PP | |
| 6 .nf | |
| 7 \f(CWtypedef struct{ | |
| 8 int needed; | |
| 9 Uint16 src_format; | |
| 10 Uint16 dest_format; | |
| 11 double rate_incr; | |
| 12 Uint8 *buf; | |
| 13 int len; | |
| 14 int len_cvt; | |
| 15 int len_mult; | |
| 16 double len_ratio; | |
| 17 void (*filters[10])(struct SDL_AudioCVT *cvt, Uint16 format); | |
| 18 int filter_index; | |
| 19 } SDL_AudioCVT;\fR | |
| 20 .fi | |
| 21 .PP | |
| 22 .SH "STRUCTURE DATA" | |
| 23 .TP 20 | |
| 24 \fBneeded\fR | |
| 25 Set to one if the conversion is possible | |
| 26 .TP 20 | |
| 27 \fBsrc_format\fR | |
| 28 Audio format of the source | |
| 29 .TP 20 | |
| 30 \fBdest_format\fR | |
| 31 Audio format of the destination | |
| 32 .TP 20 | |
| 33 \fBrate_incr\fR | |
| 34 Rate conversion increment | |
| 35 .TP 20 | |
| 36 \fBbuf\fR | |
| 37 Audio buffer | |
| 38 .TP 20 | |
| 39 \fBlen\fR | |
| 40 Length of the original audio buffer in bytes | |
| 41 .TP 20 | |
| 42 \fBlen_cvt\fR | |
| 43 Length of converted audio buffer in bytes (calculated) | |
| 44 .TP 20 | |
| 45 \fBlen_mult\fR | |
| 46 \fBbuf\fR must be \fBlen\fR*\fBlen_mult\fR bytes in size(calculated) | |
| 47 .TP 20 | |
| 48 \fBlen_ratio\fR | |
| 49 Final audio size is \fBlen\fR*\fBlen_ratio\fR | |
| 50 .TP 20 | |
| 51 \fBfilters[10](\&.\&.)\fR | |
| 52 Pointers to functions needed for this conversion | |
| 53 .TP 20 | |
| 54 \fBfilter_index\fR | |
| 55 Current conversion function | |
| 56 .SH "DESCRIPTION" | |
| 57 .PP | |
| 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\&. | |
| 59 .PP | |
| 60 Many of the fields in the \fBSDL_AudioCVT\fR structure should be considered private and their function will not be discussed here\&. | |
| 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\&. | |
| 62 .IP "\fBint\fP \fBlen\fR" 10This is the length of the original audio data in bytes\&. | |
| 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\&. | |
| 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\&. | |
| 65 .SH "SEE ALSO" | |
| 66 .PP | |
| 67 \fI\fBSDL_BuildAudioCVT\fP\fR, \fI\fBSDL_ConvertAudio\fP\fR, \fI\fBSDL_AudioSpec\fR\fR | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
68 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:58 |