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First shot at new audio data types (int32 and float32). Notable changes: - Converters between types are autogenerated. Instead of making multiple passes over the data with seperate filters for endianess, size, signedness, etc, converting between data types is always one specialized filter. This simplifies SDL_BuildAudioCVT(), which otherwise had a million edge cases with the new types, and makes the actually conversions more CPU cache friendly. Left a stub for adding specific optimized versions of these routines (SSE/MMX/Altivec, assembler, etc) - Autogenerated converters are built by SDL/src/audio/sdlgenaudiocvt.pl. This does not need to be run unless tweaking the code, and thus doesn't need integration into the build system. - Went through all the drivers and tried to weed out all the "Uint16" references that are better specified with the new SDL_AudioFormat typedef. - Cleaned out a bunch of hardcoded bitwise magic numbers and replaced them with new SDL_AUDIO_* macros. - Added initial float32 and int32 support code. Theoretically, existing drivers will push these through converters to get the data they want to feed to the hardware. Still TODO: - Optimize and debug new converters. - Update the CoreAudio backend to accept float32 data directly. - Other backends, too? - SDL_LoadWAV() needs to be updated to support int32 and float32 .wav files (both of which exist and can be generated by 'sox' for testing purposes). - Update the mixer to handle new datatypes. - Optionally update SDL_sound and SDL_mixer, etc.
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 24 Aug 2006 12:10:46 +0000
parents 355632dca928
children
line wrap: on
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<HTML
><HEAD
><TITLE
>SDL_Overlay</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Video"
HREF="video.html"><LINK
REL="PREVIOUS"
TITLE="SDL_VideoInfo"
HREF="sdlvideoinfo.html"><LINK
REL="NEXT"
TITLE="Window Management"
HREF="wm.html"></HEAD
><BODY
CLASS="REFENTRY"
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TEXT="#000000"
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VLINK="#551a8b"
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><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
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><TR
><TH
COLSPAN="3"
ALIGN="center"
>SDL Library Documentation</TH
></TR
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><TD
WIDTH="10%"
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><A
HREF="sdlvideoinfo.html"
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>Prev</A
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>Next</A
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><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLOVERLAY"
></A
>SDL_Overlay</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN3464"
></A
><H2
>Name</H2
>SDL_Overlay&nbsp;--&nbsp;YUV video overlay</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3467"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  Uint32 format;
  int w, h;
  int planes;
  Uint16 *pitches;
  Uint8 **pixels;
  Uint32 hw_overlay:1;
} SDL_Overlay;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3470"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN3472"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Overlay format (see below)</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>w, h</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Width and height of overlay</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>planes</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Number of planes in the overlay. Usually either 1 or 3</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>pitches</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>An array of pitches, one for each plane. Pitch is the length of a row in bytes.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>pixels</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>An array of pointers to teh data of each plane. The overlay should be locked before these pointers are used.</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>hw_overlay</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>This will be set to 1 if the overlay is hardware accelerated.</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3499"
></A
><H2
>Description</H2
><P
>A <SPAN
CLASS="STRUCTNAME"
>SDL_Overlay</SPAN
> is similar to a <A
HREF="sdlsurface.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Surface</SPAN
></A
> except it stores a YUV overlay. All the fields are read only, except for <TT
CLASS="STRUCTFIELD"
><I
>pixels</I
></TT
> which should be <A
HREF="sdllockyuvoverlay.html"
>locked</A
> before use. The <TT
CLASS="STRUCTFIELD"
><I
>format</I
></TT
> field stores the format of the overlay which is one of the following:
<PRE
CLASS="PROGRAMLISTING"
>#define SDL_YV12_OVERLAY  0x32315659  /* Planar mode: Y + V + U */
#define SDL_IYUV_OVERLAY  0x56555949  /* Planar mode: Y + U + V */
#define SDL_YUY2_OVERLAY  0x32595559  /* Packed mode: Y0+U0+Y1+V0 */
#define SDL_UYVY_OVERLAY  0x59565955  /* Packed mode: U0+Y0+V0+Y1 */
#define SDL_YVYU_OVERLAY  0x55595659  /* Packed mode: Y0+V0+Y1+U0 */</PRE
>
More information on YUV formats can be found at <A
HREF="http://www.webartz.com/fourcc/indexyuv.htm"
TARGET="_top"
>http://www.webartz.com/fourcc/indexyuv.htm</A
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN3510"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlcreateyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_CreateYUVOverlay</TT
></A
>,
<A
HREF="sdllockyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_LockYUVOverlay</TT
></A
>,
<A
HREF="sdlunlockyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_UnlockYUVOverlay</TT
></A
>,
<A
HREF="sdlfreeyuvoverlay.html"
><TT
CLASS="FUNCTION"
>SDL_FreeYUVOverlay</TT
></A
></P
></DIV
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>