annotate src/audio/ums/SDL_umsaudio.h @ 2661:d38309be5178 gsoc2008_audio_resampling

The windowed sinc filter generation code seems to be working fine. The FIR filtering code is also now working reasonably well. Occasionally the FIR filter will pop, but setting the normalization factor lower seems to help this. I suspect the problem is in the fixed point multiply/add. I also have a hunch the zero stuffing/sample discarding code is not correct, and I'll look at that soon to get it sorted out.
author Aaron Wishnick <schnarf@gmail.com>
date Wed, 02 Jul 2008 08:04:50 +0000
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1 /*
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2 SDL - Simple DirectMedia Layer
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3 Copyright (C) 1997-2006 Sam Lantinga
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4
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5 This library is free software; you can redistribute it and/or
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6 modify it under the terms of the GNU Lesser General Public
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7 License as published by the Free Software Foundation; either
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8 version 2.1 of the License, or (at your option) any later version.
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9
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10 This library is distributed in the hope that it will be useful,
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 Lesser General Public License for more details.
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14
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15 You should have received a copy of the GNU Lesser General Public
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16 License along with this library; if not, write to the Free Software
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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18
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19 Carsten Griwodz
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20 griff@kom.tu-darmstadt.de
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21
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22 based on linux/SDL_dspaudio.h by Sam Lantinga
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23 */
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24 #include "SDL_config.h"
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25
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26 #ifndef _SDL_UMSaudio_h
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27 #define _SDL_UMSaudio_h
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28
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29 #include <UMS/UMSAudioDevice.h>
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30
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31 #include "../SDL_sysaudio.h"
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32
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33 /* Hidden "this" pointer for the audio functions */
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34 #define _THIS SDL_AudioDevice *this
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35
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36 struct SDL_PrivateAudioData
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37 {
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38 /* Pointer to the (open) UMS audio device */
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39 Environment *ev;
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40 UMSAudioDevice umsdev;
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41
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42 /* Raw mixing buffer */
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43 UMSAudioTypes_Buffer playbuf;
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44 UMSAudioTypes_Buffer fillbuf;
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45
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46 long bytesPerSample;
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47 };
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48
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49 #endif /* _SDL_UMSaudio_h */
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50 /* vi: set ts=4 sw=4 expandtab: */