Mercurial > sdl-ios-xcode
view src/audio/sdlgenaudiocvt.pl @ 2866:e532417a6977
Fixed SDL 1.2 compatibility problem.
The API specifies that SDL_OpenAudio() will fill out the 'desired' audio spec
with the correct samples and size set by the driver. This value is important
since it may be used by applications that size audio buffers, etc.
However, we want to allow advanced applications to call SDL_OpenAudioDevice()
which gets passed a const 'desired' parameter, and have the correct data filled
into the 'obtained' parameter, possibly allowing or not allowing format changes.
So... 'obtained' becomes the audio format the user callback is expected to use,
and we add flags to allow the application to specify which format changes are
allowed.
Note: We really need to add a way to query the 'obtained' audio spec.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 13 Dec 2008 06:36:47 +0000 |
parents | 99210400e8b9 |
children | 2692999d5271 |
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#!/usr/bin/perl -w use warnings; use strict; my @audiotypes = qw( U8 S8 U16LSB S16LSB U16MSB S16MSB S32LSB S32MSB F32LSB F32MSB ); my %funcs; my $custom_converters = 0; sub outputHeader { print <<EOF; /* DO NOT EDIT! This file is generated by sdlgenaudiocvt.pl */ /* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken\@libsdl.org */ #include "SDL_config.h" #include "SDL_audio.h" #include "SDL_audio_c.h" /* *INDENT-OFF* */ EOF my @vals = ( 127, 32767, 2147483647 ); foreach (@vals) { my $val = $_; my $fval = 1.0 / $val; print("#define DIVBY${val} ${fval}f\n"); } print("\n"); } sub outputFooter { print <<EOF; /* *INDENT-ON* */ /* vi: set ts=4 sw=4 expandtab: */ EOF } sub splittype { my $t = shift; my ($signed, $size, $endian) = $t =~ /([USF])(\d+)([LM]SB|)/; my $float = ($signed eq 'F') ? 1 : 0; $signed = (($float) or ($signed eq 'S')) ? 1 : 0; $endian = 'NONE' if ($endian eq ''); my $ctype = ''; if ($float) { $ctype = (($size == 32) ? 'float' : 'double'); } else { $ctype = (($signed) ? 'S' : 'U') . "int${size}"; } return ($signed, $float, $size, $endian, $ctype); } sub getSwapFunc { my ($size, $signed, $float, $endian, $val) = @_; my $BEorLE = (($endian eq 'MSB') ? 'BE' : 'LE'); my $code = ''; if ($float) { $code = "SDL_SwapFloat${BEorLE}($val)"; } else { if ($size > 8) { $code = "SDL_Swap${BEorLE}${size}($val)"; } else { $code = $val; } if (($signed) and (!$float)) { $code = "((Sint${size}) $code)"; } } return "${code}"; } sub maxIntVal { my $size = shift; if ($size == 8) { return 0x7F; } elsif ($size == 16) { return 0x7FFF; } elsif ($size == 32) { return 0x7FFFFFFF; } die("bug in script.\n"); } sub getFloatToIntMult { my $size = shift; my $val = maxIntVal($size) . '.0'; $val .= 'f' if ($size < 32); return $val; } sub getIntToFloatDivBy { my $size = shift; return 'DIVBY' . maxIntVal($size); } sub getSignFlipVal { my $size = shift; if ($size == 8) { return '0x80'; } elsif ($size == 16) { return '0x8000'; } elsif ($size == 32) { return '0x80000000'; } die("bug in script.\n"); } sub buildCvtFunc { my ($from, $to) = @_; my ($fsigned, $ffloat, $fsize, $fendian, $fctype) = splittype($from); my ($tsigned, $tfloat, $tsize, $tendian, $tctype) = splittype($to); my $diffs = 0; $diffs++ if ($fsize != $tsize); $diffs++ if ($fsigned != $tsigned); $diffs++ if ($ffloat != $tfloat); $diffs++ if ($fendian ne $tendian); return if ($diffs == 0); my $hashid = "$from/$to"; if (1) { # !!! FIXME: if ($diffs > 1) { my $sym = "SDL_Convert_${from}_to_${to}"; $funcs{$hashid} = $sym; $custom_converters++; # Always unsigned for ints, for possible byteswaps. my $srctype = (($ffloat) ? 'float' : "Uint${fsize}"); print <<EOF; static void SDLCALL ${sym}(SDL_AudioCVT * cvt, SDL_AudioFormat format) { int i; const $srctype *src; $tctype *dst; #ifdef DEBUG_CONVERT fprintf(stderr, "Converting AUDIO_${from} to AUDIO_${to}.\\n"); #endif EOF if ($fsize < $tsize) { my $mult = $tsize / $fsize; print <<EOF; src = (const $srctype *) (cvt->buf + cvt->len_cvt); dst = ($tctype *) (cvt->buf + cvt->len_cvt * $mult); for (i = cvt->len_cvt / sizeof ($srctype); i; --i, --src, --dst) { EOF } else { print <<EOF; src = (const $srctype *) cvt->buf; dst = ($tctype *) cvt->buf; for (i = cvt->len_cvt / sizeof ($srctype); i; --i, ++src, ++dst) { EOF } # Have to convert to/from float/int. # !!! FIXME: cast through double for int32<->float? my $code = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, '*src'); if ($ffloat != $tfloat) { if ($ffloat) { my $mult = getFloatToIntMult($tsize); if (!$tsigned) { # bump from -1.0f/1.0f to 0.0f/2.0f $code = "($code + 1.0f)"; } $code = "(($tctype) ($code * $mult))"; } else { # $divby will be the reciprocal, to avoid pipeline stalls # from floating point division...so multiply it. my $divby = getIntToFloatDivBy($fsize); $code = "(((float) $code) * $divby)"; if (!$fsigned) { # bump from 0.0f/2.0f to -1.0f/1.0f. $code = "($code - 1.0f)"; } } } else { # All integer conversions here. if ($fsigned != $tsigned) { my $signflipval = getSignFlipVal($fsize); $code = "(($code) ^ $signflipval)"; } my $shiftval = abs($fsize - $tsize); if ($fsize < $tsize) { $code = "((($tctype) $code) << $shiftval)"; } elsif ($fsize > $tsize) { $code = "(($tctype) ($code >> $shiftval))"; } } my $swap = getSwapFunc($tsize, $tsigned, $tfloat, $tendian, 'val'); print <<EOF; const $tctype val = $code; *dst = ${swap}; } EOF if ($fsize > $tsize) { my $divby = $fsize / $tsize; print(" cvt->len_cvt /= $divby;\n"); } elsif ($fsize < $tsize) { my $mult = $tsize / $fsize; print(" cvt->len_cvt *= $mult;\n"); } print <<EOF; format = AUDIO_$to; if (cvt->filters[++cvt->filter_index]) { cvt->filters[cvt->filter_index] (cvt, format); } } EOF } else { if ($fsigned != $tsigned) { $funcs{$hashid} = 'SDL_ConvertSigned'; } elsif ($ffloat != $tfloat) { $funcs{$hashid} = 'SDL_ConvertFloat'; } elsif ($fsize != $tsize) { $funcs{$hashid} = 'SDL_ConvertSize'; } elsif ($fendian ne $tendian) { $funcs{$hashid} = 'SDL_ConvertEndian'; } else { die("error in script.\n"); } } } outputHeader(); foreach (@audiotypes) { my $from = $_; foreach (@audiotypes) { my $to = $_; buildCvtFunc($from, $to); } } print <<EOF; const SDL_AudioTypeFilters sdl_audio_type_filters[] = { EOF foreach (@audiotypes) { my $from = $_; foreach (@audiotypes) { my $to = $_; if ($from ne $to) { my $hashid = "$from/$to"; my $sym = $funcs{$hashid}; print(" { AUDIO_$from, AUDIO_$to, $sym },\n"); } } } print <<EOF; }; EOF outputFooter(); exit 0; # end of sdlgenaudiocvt.pl ...