Mercurial > sdl-ios-xcode
annotate src/audio/SDL_wave.h @ 3880:74e828c64315 SDL-1.2
Fixed bug #292
I might be on crack here.
It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and
right channels of a stereo stream together, and clamps the new mono channel if
it would overflow.
Shouldn't it be dividing by 2 to average the two sample points instead of
clamping? Otherwise the mono sample point's volume doubles in the conversion.
This would also make the conversion faster, as it replaces two branches per
sample frame with a bitwise shift.
--ryan.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 24 Sep 2006 15:45:37 +0000 |
| parents | 7995cc87b777 |
| children | 782fd950bd46 a1b03ba2fcd0 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
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Updated copyright information and removed rcs id lines (problematic in branch merges)
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3 Copyright (C) 1997-2006 Sam Lantinga |
| 0 | 4 |
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Use SDL_ prefixed versions of C library functions.
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5 This library is SDL_free software; you can redistribute it and/or |
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
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6 modify it under the terms of the GNU Lesser General Public |
| 0 | 7 License as published by the Free Software Foundation; either |
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Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
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8 version 2.1 of the License, or (at your option) any later version. |
| 0 | 9 |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
|
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c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
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13 Lesser General Public License for more details. |
| 0 | 14 |
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c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
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15 You should have received a copy of the GNU Lesser General Public |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
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16 License along with this library; if not, write to the Free Software |
|
c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
769
diff
changeset
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 0 | 18 |
| 19 Sam Lantinga | |
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20 slouken@libsdl.org |
| 0 | 21 */ |
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Use consistent identifiers for the various platforms we support.
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22 #include "SDL_config.h" |
| 0 | 23 |
| 24 /* WAVE files are little-endian */ | |
| 25 | |
| 26 /*******************************************/ | |
| 27 /* Define values for Microsoft WAVE format */ | |
| 28 /*******************************************/ | |
| 29 #define RIFF 0x46464952 /* "RIFF" */ | |
| 30 #define WAVE 0x45564157 /* "WAVE" */ | |
| 31 #define FACT 0x74636166 /* "fact" */ | |
| 32 #define LIST 0x5453494c /* "LIST" */ | |
| 33 #define FMT 0x20746D66 /* "fmt " */ | |
| 34 #define DATA 0x61746164 /* "data" */ | |
| 35 #define PCM_CODE 0x0001 | |
| 36 #define MS_ADPCM_CODE 0x0002 | |
| 37 #define IMA_ADPCM_CODE 0x0011 | |
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Fixed some bugs in string handling
Sam Lantinga <slouken@libsdl.org>
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38 #define MP3_CODE 0x0055 |
| 0 | 39 #define WAVE_MONO 1 |
| 40 #define WAVE_STEREO 2 | |
| 41 | |
| 42 /* Normally, these three chunks come consecutively in a WAVE file */ | |
| 43 typedef struct WaveFMT { | |
| 44 /* Not saved in the chunk we read: | |
| 45 Uint32 FMTchunk; | |
| 46 Uint32 fmtlen; | |
| 47 */ | |
| 48 Uint16 encoding; | |
| 49 Uint16 channels; /* 1 = mono, 2 = stereo */ | |
| 50 Uint32 frequency; /* One of 11025, 22050, or 44100 Hz */ | |
| 51 Uint32 byterate; /* Average bytes per second */ | |
| 52 Uint16 blockalign; /* Bytes per sample block */ | |
| 53 Uint16 bitspersample; /* One of 8, 12, 16, or 4 for ADPCM */ | |
| 54 } WaveFMT; | |
| 55 | |
| 56 /* The general chunk found in the WAVE file */ | |
| 57 typedef struct Chunk { | |
| 58 Uint32 magic; | |
| 59 Uint32 length; | |
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*** empty log message ***
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60 Uint8 *data; |
| 0 | 61 } Chunk; |
| 62 |