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view docs/html/sdlaudiospec.html @ 3958:85b6fb6a5e3c SDL-1.2

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Actually, this is a better fix...clear the error state once if everything we need loaded; it's more efficient, and works even if the last unnecessary xrandr symbol failed to load. Otherwise, leave the original loadso error, so the end user can find out what symbol failed.
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 13 Jun 2007 08:00:10 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>SDL_AudioSpec</TITLE
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><H1
><A
NAME="SDLAUDIOSPEC"
></A
>SDL_AudioSpec</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN6507"
></A
><H2
>Name</H2
>SDL_AudioSpec&nbsp;--&nbsp;Audio Specification Structure</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6510"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  int freq;
  Uint16 format;
  Uint8 channels;
  Uint8 silence;
  Uint16 samples;
  Uint32 size;
  void (*callback)(void *userdata, Uint8 *stream, int len);
  void *userdata;
} SDL_AudioSpec;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6513"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6515"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio frequency in samples per second</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio data format</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Number of channels: 1 mono, 2 stereo</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>silence</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer silence value (calculated)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer size in samples</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>size</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Audio buffer size in bytes (calculated)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>callback(..)</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Callback function for filling the audio buffer</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>userdata</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Pointer the user data which is passed to the callback function</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6550"
></A
><H2
>Description</H2
><P
>The <SPAN
CLASS="STRUCTNAME"
>SDL_AudioSpec</SPAN
> structure is used to describe the format of some audio data. This structure is used by <A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
> and <A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
>. While all fields are used by <TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
> only <TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
>, <TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
>, <TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
> and <TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
> are used by <TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
>. We will detail these common members here.</P
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN6564"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>freq</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>Specifies the size and type of each sample element
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>AUDIO_U8</TT
></DT
><DD
><P
>Unsigned 8-bit samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S8</TT
></DT
><DD
><P
>Signed 8-bit samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16</TT
> or <TT
CLASS="LITERAL"
>AUDIO_U16LSB</TT
></DT
><DD
><P
>Unsigned 16-bit little-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16</TT
> or <TT
CLASS="LITERAL"
>AUDIO_S16LSB</TT
></DT
><DD
><P
>Signed 16-bit little-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16MSB</TT
></DT
><DD
><P
>Unsigned 16-bit big-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16MSB</TT
></DT
><DD
><P
>Signed 16-bit big-endian samples</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_U16SYS</TT
></DT
><DD
><P
>Either <TT
CLASS="LITERAL"
>AUDIO_U16LSB</TT
> or <TT
CLASS="LITERAL"
>AUDIO_U16MSB</TT
> depending on you systems endianness</P
></DD
><DT
><TT
CLASS="LITERAL"
>AUDIO_S16SYS</TT
></DT
><DD
><P
>Either <TT
CLASS="LITERAL"
>AUDIO_S16LSB</TT
> or <TT
CLASS="LITERAL"
>AUDIO_S16MSB</TT
> depending on you systems endianness</P
></DD
></DL
></DIV
></P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>channels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>When used with <A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
> this refers to the size of the audio buffer in samples. A sample a chunk of audio data of the size specified in <TT
CLASS="PARAMETER"
><I
>format</I
></TT
> mulitplied by the number of channels. When the <SPAN
CLASS="STRUCTNAME"
>SDL_AudioSpec</SPAN
> is used with <A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
> <TT
CLASS="STRUCTFIELD"
><I
>samples</I
></TT
> is set to 4096.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6639"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlopenaudio.html"
><TT
CLASS="FUNCTION"
>SDL_OpenAudio</TT
></A
>,
<A
HREF="sdlloadwav.html"
><TT
CLASS="FUNCTION"
>SDL_LoadWAV</TT
></A
></P
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