Mercurial > sdl-ios-xcode
view src/video/Xext/extensions/Xvlib.h @ 942:41a59de7f2ed
Here are patches for SDL12 and SDL_mixer for 4 or 6 channel
surround sound on Linux using the Alsa driver. To use them, naturally
you need a sound card that will do 4 or 6 channels and probably also a
recent version of the Alsa drivers and library. Since the only SDL
output driver that knows about surround sound is the Alsa driver,
you���ll want to choose it, using:
export SDL_AUDIODRIVER=alsa
There are no syntactic changes to the programming API. No new
library calls, no differences in arguments.
There are two semantic changes:
(1) For library calls with number of channels as an argument, formerly
you could use only 1 or 2 for the number of channels. Now you
can also use 4 or 6.
(2) The two "left" and "right" arguments to Mix_SetPanning, for the
case of 4 or 6 channels, no longer simply control the volumes of
the left and right channels. Now the "left" argument is converted
to an angle and Mix_SetPosition is called, and the "right" argu-
ment is ignored.
With two exceptions, so far as I know, the modified SDL12 and
SDL_mixer work the same way as the original versions, when opened for
1 or 2 channel output. The two exceptions are bugs which I fixed.
Well, the first, anyway, is a bug for sure. When rate conversions up
or down by a factor of two are applied (in src/audio/SDL_audiocvt.c),
streams with different numbers of channels (that is, mono and stereo)
are treated the same way: either each sample is copied or every other
sample is omitted. This is ok for mono, but for stereo, it is frames
that should be copied or omitted, where by "frame" I mean a portion of
the stream containing one sample for each channel. (In the SDL source,
confusingly, sometimes frames are called "samples".) So for these
rate conversions, stereo streams have to be treated differently, and
they are, in my modified version.
The other problem that might be characterized as a bug arises
when SDL_mixer is passed a multichannel chunk which does not have an
integral number of frames. Due to the way the effect_position code
loops over frames, when the chunk ends with a partial frame, memory
outside the chunk buffer will be accessed. In the case of stereo,
it���s possible that because malloc may give more memory than requested,
this potential problem never actually causes a segment fault. I don���t
know. For 6 channel chunks, I do know, and it does cause segment
faults.
If SDL_mixer is passed defective chunks and this causes a segment
fault, arguably, that���s not a bug in SDL_mixer. Still, whether or not
it counts as a bug, it���s easy to protect against, so why not? I added
code in mixer.c to discard any partial frame at the end of a chunk.
Then what about when SDL or SDL_mixer is opened for 4 or 6 chan-
nel output? What happens with the parts of the current library
designed for stereo? I don���t know whether I���ve covered all the bases,
but I���ve tried:
(1) For playing 2 channel waves, or other cases where SDL knows it has
to match up a 2 channel source with a 4 or 6 channel output, I���ve
added code in SDL_audiocvt.c to make the necessary conversions.
(2) For playing midis using timidity, I���ve converted timidity to do 4
or 6 channel output, upon request.
(3) For playing mods using mikmod, I put ad hoc code in music.c to
convert the stereo output that mikmod produces to 4 or 6 chan-
nels. Obviously it would be better to change the mikmod code to
mix down into 4 or 6 channels, but I have a hard time following
the code in mikmod, so I didn���t do that.
(4) For playing mp3s, I put ad hoc code in smpeg to copy channels in
the case when 4 or 6 channel output is needed.
(5) There seems to be no problem with .ogg files - stereo .oggs can be
up converted as .wavs are.
(6) The effect_position code in SDL_mixer is now generalized to in-
clude the cases of 4 and 6 channel streams.
I���ve done a very limited amount of compatibility testing for some
of the games using SDL I happen to have. For details, see the file
TESTS.
I���ve put into a separate archive, Surround-SDL-testfiles.tgz, a
couple of 6 channel wave files for testing and a 6 channel ogg file.
If you have the right hardware and version of Alsa, you should be able
to play the wave files with the Alsa utility aplay (and hear all
channels, except maybe lfe, for chan-id.wav, since it���s rather faint).
Don���t expect aplay to give good sound, though. There���s something
wrong with the current version of aplay.
The canyon.ogg file is to test loading of 6 channel oggs. After
patching and compiling, you can play it with playmus. (My version of
ogg123 will not play it, and I had to patch mplayer to get it to play
6 channel oggs.)
Greg Lee <greg@ling.lll.hawaii.edu>
Thus, July 1, 2004
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 21 Aug 2004 12:27:02 +0000 |
parents | 585a7e1285ae |
children | 0c105755b110 |
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/*********************************************************** Copyright 1991 by Digital Equipment Corporation, Maynard, Massachusetts, and the Massachusetts Institute of Technology, Cambridge, Massachusetts. All Rights Reserved Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the names of Digital or MIT not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. ******************************************************************/ /* $XFree86: xc/include/extensions/Xvlib.h,v 1.3 1999/12/11 19:28:48 mvojkovi Exp $ */ #ifndef XVLIB_H #define XVLIB_H /* ** File: ** ** Xvlib.h --- Xv library public header file ** ** Author: ** ** David Carver (Digital Workstation Engineering/Project Athena) ** ** Revisions: ** ** 26.06.91 Carver ** - changed XvFreeAdaptors to XvFreeAdaptorInfo ** - changed XvFreeEncodings to XvFreeEncodingInfo ** ** 11.06.91 Carver ** - changed SetPortControl to SetPortAttribute ** - changed GetPortControl to GetPortAttribute ** - changed QueryBestSize ** ** 05.15.91 Carver ** - version 2.0 upgrade ** ** 01.24.91 Carver ** - version 1.4 upgrade ** */ #include <X11/Xfuncproto.h> #include <XFree86/extensions/Xv.h> #include "SDL_name.h" typedef struct { int numerator; int denominator; } SDL_NAME(XvRational); typedef struct { int flags; /* XvGettable, XvSettable */ int min_value; int max_value; char *name; } SDL_NAME(XvAttribute); typedef struct { XvEncodingID encoding_id; char *name; unsigned long width; unsigned long height; SDL_NAME(XvRational) rate; unsigned long num_encodings; } SDL_NAME(XvEncodingInfo); typedef struct { char depth; unsigned long visual_id; } SDL_NAME(XvFormat); typedef struct { XvPortID base_id; unsigned long num_ports; char type; char *name; unsigned long num_formats; SDL_NAME(XvFormat) *formats; unsigned long num_adaptors; } SDL_NAME(XvAdaptorInfo); typedef struct { int type; unsigned long serial; /* # of last request processed by server */ Bool send_event; /* true if this came from a SendEvent request */ Display *display; /* Display the event was read from */ Drawable drawable; /* drawable */ unsigned long reason; /* what generated this event */ XvPortID port_id; /* what port */ Time time; /* milliseconds */ } SDL_NAME(XvVideoNotifyEvent); typedef struct { int type; unsigned long serial; /* # of last request processed by server */ Bool send_event; /* true if this came from a SendEvent request */ Display *display; /* Display the event was read from */ XvPortID port_id; /* what port */ Time time; /* milliseconds */ Atom attribute; /* atom that identifies attribute */ long value; /* value of attribute */ } SDL_NAME(XvPortNotifyEvent); typedef union { int type; SDL_NAME(XvVideoNotifyEvent) xvvideo; SDL_NAME(XvPortNotifyEvent) xvport; long pad[24]; } SDL_NAME(XvEvent); typedef struct { int id; /* Unique descriptor for the format */ int type; /* XvRGB, XvYUV */ int byte_order; /* LSBFirst, MSBFirst */ char guid[16]; /* Globally Unique IDentifier */ int bits_per_pixel; int format; /* XvPacked, XvPlanar */ int num_planes; /* for RGB formats only */ int depth; unsigned int red_mask; unsigned int green_mask; unsigned int blue_mask; /* for YUV formats only */ unsigned int y_sample_bits; unsigned int u_sample_bits; unsigned int v_sample_bits; unsigned int horz_y_period; unsigned int horz_u_period; unsigned int horz_v_period; unsigned int vert_y_period; unsigned int vert_u_period; unsigned int vert_v_period; char component_order[32]; /* eg. UYVY */ int scanline_order; /* XvTopToBottom, XvBottomToTop */ } SDL_NAME(XvImageFormatValues); typedef struct { int id; int width, height; int data_size; /* bytes */ int num_planes; int *pitches; /* bytes */ int *offsets; /* bytes */ char *data; XPointer obdata; } SDL_NAME(XvImage); _XFUNCPROTOBEGIN extern int SDL_NAME(XvQueryExtension)( #if NeedFunctionPrototypes Display* /* display */, unsigned int* /* p_version */, unsigned int* /* p_revision */, unsigned int* /* p_requestBase */, unsigned int* /* p_eventBase */, unsigned int* /* p_errorBase */ #endif ); extern int SDL_NAME(XvQueryAdaptors)( #if NeedFunctionPrototypes Display* /* display */, Window /* window */, unsigned int* /* p_nAdaptors */, SDL_NAME(XvAdaptorInfo)** /* p_pAdaptors */ #endif ); extern int SDL_NAME(XvQueryEncodings)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, unsigned int* /* p_nEncoding */, SDL_NAME(XvEncodingInfo)** /* p_pEncoding */ #endif ); extern int SDL_NAME(XvPutVideo)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Drawable /* d */, GC /* gc */, int /* vx */, int /* vy */, unsigned int /* vw */, unsigned int /* vh */, int /* dx */, int /* dy */, unsigned int /* dw */, unsigned int /* dh */ #endif ); extern int SDL_NAME(XvPutStill)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Drawable /* d */, GC /* gc */, int /* vx */, int /* vy */, unsigned int /* vw */, unsigned int /* vh */, int /* dx */, int /* dy */, unsigned int /* dw */, unsigned int /* dh */ #endif ); extern int SDL_NAME(XvGetVideo)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Drawable /* d */, GC /* gc */, int /* vx */, int /* vy */, unsigned int /* vw */, unsigned int /* vh */, int /* dx */, int /* dy */, unsigned int /* dw */, unsigned int /* dh */ #endif ); extern int SDL_NAME(XvGetStill)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Drawable /* d */, GC /* gc */, int /* vx */, int /* vy */, unsigned int /* vw */, unsigned int /* vh */, int /* dx */, int /* dy */, unsigned int /* dw */, unsigned int /* dh */ #endif ); extern int SDL_NAME(XvStopVideo)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Drawable /* drawable */ #endif ); extern int SDL_NAME(XvGrabPort)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Time /* time */ #endif ); extern int SDL_NAME(XvUngrabPort)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Time /* time */ #endif ); extern int SDL_NAME(XvSelectVideoNotify)( #if NeedFunctionPrototypes Display* /* display */, Drawable /* drawable */, Bool /* onoff */ #endif ); extern int SDL_NAME(XvSelectPortNotify)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Bool /* onoff */ #endif ); extern int SDL_NAME(XvSetPortAttribute)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Atom /* attribute */, int /* value */ #endif ); extern int SDL_NAME(XvGetPortAttribute)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Atom /* attribute */, int* /* p_value */ #endif ); extern int SDL_NAME(XvQueryBestSize)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, Bool /* motion */, unsigned int /* vid_w */, unsigned int /* vid_h */, unsigned int /* drw_w */, unsigned int /* drw_h */, unsigned int* /* p_actual_width */, unsigned int* /* p_actual_width */ #endif ); extern SDL_NAME(XvAttribute)* SDL_NAME(XvQueryPortAttributes)( #if NeedFunctionPrototypes Display* /* display */, XvPortID /* port */, int* /* number */ #endif ); extern void SDL_NAME(XvFreeAdaptorInfo)( #if NeedFunctionPrototypes SDL_NAME(XvAdaptorInfo)* /* adaptors */ #endif ); extern void SDL_NAME(XvFreeEncodingInfo)( #if NeedFunctionPrototypes SDL_NAME(XvEncodingInfo)* /* encodings */ #endif ); extern SDL_NAME(XvImageFormatValues) * SDL_NAME(XvListImageFormats) ( #if NeedFunctionPrototypes Display *display, XvPortID port_id, int *count_return #endif ); extern SDL_NAME(XvImage) * SDL_NAME(XvCreateImage) ( #if NeedFunctionPrototypes Display *display, XvPortID port, int id, char *data, int width, int height #endif ); extern int SDL_NAME(XvPutImage) ( #if NeedFunctionPrototypes Display *display, XvPortID id, Drawable d, GC gc, SDL_NAME(XvImage) *image, int src_x, int src_y, unsigned int src_w, unsigned int src_h, int dest_x, int dest_y, unsigned int dest_w, unsigned int dest_h #endif ); extern int SDL_NAME(XvShmPutImage) ( #if NeedFunctionPrototypes Display *display, XvPortID id, Drawable d, GC gc, SDL_NAME(XvImage) *image, int src_x, int src_y, unsigned int src_w, unsigned int src_h, int dest_x, int dest_y, unsigned int dest_w, unsigned int dest_h, Bool send_event #endif ); #ifdef _XSHM_H_ extern SDL_NAME(XvImage) * SDL_NAME(XvShmCreateImage) ( #if NeedFunctionPrototypes Display *display, XvPortID port, int id, char* data, int width, int height, XShmSegmentInfo *shminfo #endif ); #endif _XFUNCPROTOEND #endif /* XVLIB_H */