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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 355632dca928
children
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>SDL_ConvertAudio</TITLE
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><H1
><A
NAME="SDLCONVERTAUDIO"
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>SDL_ConvertAudio</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN7048"
></A
><H2
>Name</H2
>SDL_ConvertAudio&nbsp;--&nbsp;Convert audio data to a desired audio format.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN7051"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN7052"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_ConvertAudio</B
></CODE
>(SDL_AudioCVT *cvt);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7058"
></A
><H2
>Description</H2
><P
><TT
CLASS="FUNCTION"
>SDL_ConvertAudio</TT
> takes one parameter, <TT
CLASS="PARAMETER"
><I
>cvt</I
></TT
>, which was previously initilized. Initilizing a <A
HREF="sdlaudiocvt.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_AudioCVT</SPAN
></A
> is a two step process. First of all, the structure must be passed to <A
HREF="sdlbuildaudiocvt.html"
><TT
CLASS="FUNCTION"
>SDL_BuildAudioCVT</TT
></A
> along with source and destination format parameters. Secondly, the <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>buf</I
></TT
> and <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>len</I
></TT
> fields must be setup. <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>buf</I
></TT
> should point to the audio data and <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>len</I
></TT
> should be set to the length of the audio data in bytes. Remember, the length of the buffer pointed to by <TT
CLASS="STRUCTFIELD"
><I
>buf</I
></TT
> show be <TT
CLASS="STRUCTFIELD"
><I
>len</I
></TT
>*<TT
CLASS="STRUCTFIELD"
><I
>len_mult</I
></TT
> bytes in length.</P
><P
>Once the <SPAN
CLASS="STRUCTNAME"
>SDL_AudioCVT</SPAN
>structure is initilized then we can pass it to <TT
CLASS="FUNCTION"
>SDL_ConvertAudio</TT
>, which will convert the audio data pointer to by <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>buf</I
></TT
>. If <TT
CLASS="FUNCTION"
>SDL_ConvertAudio</TT
> returned <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> then the conversion was completed successfully, otherwise <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> is returned.</P
><P
>If the conversion completed successfully then the converted audio data can be read from <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>buf</I
></TT
>. The amount of valid, converted, audio data in the buffer is equal to <SPAN
CLASS="STRUCTNAME"
>cvt</SPAN
>-&#62;<TT
CLASS="STRUCTFIELD"
><I
>len</I
></TT
>*<TT
CLASS="STRUCTFIELD"
><I
>cvt</I
></TT
>-&#62;<SPAN
CLASS="STRUCTNAME"
>len_ratio</SPAN
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN7093"
></A
><H2
>Examples</H2
><PRE
CLASS="PROGRAMLISTING"
>/* Converting some WAV data to hardware format */
void my_audio_callback(void *userdata, Uint8 *stream, int len);

SDL_AudioSpec *desired, *obtained;
SDL_AudioSpec wav_spec;
SDL_AudioCVT  wav_cvt;
Uint32 wav_len;
Uint8 *wav_buf;
int ret;

/* Allocated audio specs */
desired = malloc(sizeof(SDL_AudioSpec));
obtained = malloc(sizeof(SDL_AudioSpec));

/* Set desired format */
desired-&#62;freq=22050;
desired-&#62;format=AUDIO_S16LSB;
desired-&#62;samples=8192;
desired-&#62;callback=my_audio_callback;
desired-&#62;userdata=NULL;

/* Open the audio device */
if ( SDL_OpenAudio(desired, obtained) &#60; 0 ){
  fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
  exit(-1);
}
        
free(desired);

/* Load the test.wav */
if( SDL_LoadWAV("test.wav", &#38;wav_spec, &#38;wav_buf, &#38;wav_len) == NULL ){
  fprintf(stderr, "Could not open test.wav: %s\n", SDL_GetError());
  SDL_CloseAudio();
  free(obtained);
  exit(-1);
}
                                            
/* Build AudioCVT */
ret = SDL_BuildAudioCVT(&#38;wav_cvt,
                        wav_spec.format, wav_spec.channels, wav_spec.freq,
                        obtained-&#62;format, obtained-&#62;channels, obtained-&#62;freq);

/* Check that the convert was built */
if(ret==-1){
  fprintf(stderr, "Couldn't build converter!\n");
  SDL_CloseAudio();
  free(obtained);
  SDL_FreeWAV(wav_buf);
}

/* Setup for conversion */
wav_cvt.buf = malloc(wav_len * wav_cvt.len_mult);
wav_cvt.len = wav_len;
memcpy(wav_cvt.buf, wav_buf, wav_len);

/* We can delete to original WAV data now */
SDL_FreeWAV(wav_buf);

/* And now we're ready to convert */
SDL_ConvertAudio(&#38;wav_cvt);

/* do whatever */
.
.
.
.
&#13;</PRE
></DIV
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdlbuildaudiocvt.html"
><TT
CLASS="FUNCTION"
>SDL_BuildAudioCVT</TT
></A
>,
<A
HREF="sdlaudiocvt.html"
><TT
CLASS="FUNCTION"
>SDL_AudioCVT</TT
></A
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