annotate decoders/skeleton.c @ 21:d9b9d60cf9a9

Added some helpful info to FMT_open()...
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 19 Sep 2001 08:30:46 +0000
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children ea58bc3b15d7
rev   line source
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1 /*
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2 * SDL_sound -- An abstract sound format decoding API.
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3 * Copyright (C) 2001 Ryan C. Gordon.
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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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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18 */
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19
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20 /*
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21 * FMT decoder for SDL_sound.
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22 *
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23 * This driver handles FMT audio data. Blahblahblah... The author should
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24 * have done a search and replace on "fmt" and "FMT" and changed this
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25 * comment. This is the default comment in the skeleton decoder file...
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26 *
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27 * Please see the file LICENSE in the source's root directory.
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28 *
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29 * This file written by Ryan C. Gordon. (icculus@clutteredmind.org)
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30 */
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31
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32 #include <stdio.h>
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33 #include <stdlib.h>
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34 #include <string.h>
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35 #include <assert.h>
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36 #include "SDL_sound.h"
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37
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38 #define __SDL_SOUND_INTERNAL__
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39 #include "SDL_sound_internal.h"
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40
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41 #if (!defined SOUND_SUPPORTS_FMT)
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42 #error SOUND_SUPPORTS_FMT must be defined.
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43 #endif
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44
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45
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46 static int FMT_open(Sound_Sample *sample, const char *ext);
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47 static void FMT_close(Sound_Sample *sample);
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48 static Uint32 FMT_read(Sound_Sample *sample);
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49
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50 const Sound_DecoderFunctions __Sound_DecoderFunctions_FMT =
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51 {
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52 {
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53 "FMT",
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54 "FMT audio format description",
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55 "Ryan C. Gordon <icculus@clutteredmind.org>",
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56 "http://www.icculus.org/SDL_sound/"
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57 },
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58
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59 FMT_open, /* open() method */
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60 FMT_close, /* close() method */
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61 FMT_read /* read() method */
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62 };
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63
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64
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65 static int FMT_open(Sound_Sample *sample, const char *ext)
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66 {
21
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67 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
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68 SDL_RWops *rw = internal->rw;
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69
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70 if (can NOT accept the data)
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71 {
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72 Sound_SetError("FMT: expected X, got Y.");
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73 return(0);
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74 } /* if */
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75
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76 _D(("FMT: Accepting data stream.\n"));
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77 set up sample->actual;
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78 sample->flags = SOUND_SAMPLEFLAG_NONE;
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79 return(1); /* we'll handle this data. */
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80 } /* FMT_open */
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81
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82
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83 static void FMT_close(Sound_Sample *sample)
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84 {
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85 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
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86 clean up anything you put into internal->decoder_private;
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87 } /* FMT_close */
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88
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89
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90 static Uint32 FMT_read(Sound_Sample *sample)
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91 {
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92 Uint32 retval;
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93 Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque;
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94
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95 /*
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96 * We don't actually do any decoding, so we read the fmt data
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97 * directly into the internal buffer...
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98 */
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99 retval = SDL_RWread(internal->rw, internal->buffer,
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100 1, internal->buffer_size);
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101
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102 (or whatever. Do some decoding here...)
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103
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104 /* Make sure the read went smoothly... */
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105 if (retval == 0)
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106 sample->flags |= SOUND_SAMPLEFLAG_EOF;
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107
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108 else if (retval == -1)
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109 sample->flags |= SOUND_SAMPLEFLAG_ERROR;
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110
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111 /* (next call this EAGAIN may turn into an EOF or error.) */
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112 else if (retval < internal->buffer_size)
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113 sample->flags |= SOUND_SAMPLEFLAG_EAGAIN;
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114
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115 (or whatever. retval == number of bytes you put in internal->buffer).
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116
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117 return(retval);
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118 } /* FMT_read */
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119
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120
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121 /* end of fmt.c ... */
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122