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comparison src/audio/mint/SDL_mintaudio.c @ 961:185acc07127a

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Date: Fri, 29 Oct 2004 11:47:09 +0200 From: Patrice Mandin Subject: Reworked audio drivers for Atari platform These are reworked audio drivers for the Atari platform. Previous drivers were missing some features: - Test external clock plugged to DSP port on Atari Falcon 030. - Ability to select internal or external clock. So now, I generate a list of frequencies available, with the master clock and predivisor to use. One big caveat to this: I do not have an external clock, so I hope it works.
author Patrice Mandin <patmandin@gmail.com>
date Fri, 29 Oct 2004 09:56:53 +0000
parents b8d311d90021
children 2eca15c3f609
comparison
equal deleted inserted replaced
960:eec28a5278be 961:185acc07127a
39 SDL_AudioDevice *SDL_MintAudio_device; 39 SDL_AudioDevice *SDL_MintAudio_device;
40 Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */ 40 Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */
41 unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */ 41 unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */
42 unsigned short SDL_MintAudio_numbuf; /* Buffer to play */ 42 unsigned short SDL_MintAudio_numbuf; /* Buffer to play */
43 unsigned short SDL_MintAudio_mutex; 43 unsigned short SDL_MintAudio_mutex;
44 unsigned long SDL_MintAudio_clocktics;
44 cookie_stfa_t *SDL_MintAudio_stfa; 45 cookie_stfa_t *SDL_MintAudio_stfa;
45 46
46 /* The callback function, called by each driver whenever needed */ 47 /* The callback function, called by each driver whenever needed */
47 48
48 void SDL_MintAudio_Callback(void) 49 void SDL_MintAudio_Callback(void)
62 SDL_MintAudio_device->spec.callback(SDL_MintAudio_device->spec.userdata, buffer, SDL_MintAudio_device->spec.size); 63 SDL_MintAudio_device->spec.callback(SDL_MintAudio_device->spec.userdata, buffer, SDL_MintAudio_device->spec.size);
63 } 64 }
64 } 65 }
65 } 66 }
66 67
67 /* Simple function to search for the nearest frequency */ 68 /* Add a new frequency/clock/predivisor to the current list */
68 int SDL_MintAudio_SearchFrequency(_THIS, int falcon_codec, int desired_freq) 69 void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock, Uint32 prediv)
70 {
71 int i, p;
72
73 if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) {
74 return;
75 }
76
77 /* Search where to insert the frequency (highest first) */
78 for (p=0; p<MINTAUDIO_freqcount; p++) {
79 if (frequency > MINTAUDIO_frequencies[p].frequency) {
80 break;
81 }
82 }
83
84 /* Put all following ones farer */
85 if (MINTAUDIO_freqcount>0) {
86 for (i=MINTAUDIO_freqcount; i>p; i--) {
87 MINTAUDIO_frequencies[i].frequency = MINTAUDIO_frequencies[i-1].frequency;
88 MINTAUDIO_frequencies[i].masterclock = MINTAUDIO_frequencies[i-1].masterclock;
89 MINTAUDIO_frequencies[i].predivisor = MINTAUDIO_frequencies[i-1].predivisor;
90 }
91 }
92
93 /* And insert new one */
94 MINTAUDIO_frequencies[p].frequency = frequency;
95 MINTAUDIO_frequencies[p].masterclock = clock;
96 MINTAUDIO_frequencies[p].predivisor = prediv;
97
98 MINTAUDIO_freqcount++;
99 }
100
101 /* Search for the nearest frequency */
102 int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq)
69 { 103 {
70 int i; 104 int i;
71 105
72 /* Only 1 freq ? */ 106 /* Only 1 freq ? */
73 if (MINTAUDIO_nfreq==1) { 107 if (MINTAUDIO_freqcount==1) {
74 return(MINTAUDIO_sfreq); 108 return 0;
75 } 109 }
76 110
77 /* Check the array */ 111 /* Check the array */
78 for (i=MINTAUDIO_sfreq; i<MINTAUDIO_nfreq-1; i++) { 112 for (i=0; i<MINTAUDIO_freqcount; i++) {
79 /* Remove unusable falcon codec frequencies */ 113 if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+
80 if (falcon_codec) { 114 MINTAUDIO_frequencies[i+1].frequency)>>1)) {
81 if ((i==6) || (i==8) || (i==10)) {
82 continue;
83 }
84 }
85
86 if (desired_freq >= ((MINTAUDIO_hardfreq[i]+MINTAUDIO_hardfreq[i+1])>>1)) {
87 return i; 115 return i;
88 } 116 }
89 } 117 }
90 118
91 /* Not in the array, give the latest */ 119 /* Not in the array, give the latest */
92 return MINTAUDIO_nfreq-1; 120 return MINTAUDIO_freqcount-1;
93 } 121 }