1 /* 2 * QEMU NULL audio output driver 3 * 4 * Copyright (c) 2004 Vassili Karpov (malc) 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "vl.h" 25 26 #include "audio/audio_int.h" 27 28 typedef struct NoVoice { 29 HWVoice hw; 30 int64_t old_ticks; 31 } NoVoice; 32 33 #define dolog(...) AUD_log ("noaudio", __VA_ARGS__) 34 #ifdef DEBUG 35 #define ldebug(...) dolog (__VA_ARGS__) 36 #else 37 #define ldebug(...) 38 #endif 39 40 static void no_hw_run (HWVoice *hw) 41 { 42 NoVoice *no = (NoVoice *) hw; 43 int rpos, live, decr, samples; 44 uint8_t *dst; 45 st_sample_t *src; 46 int64_t now = qemu_get_clock (vm_clock); 47 int64_t ticks = now - no->old_ticks; 48 int64_t bytes = (ticks * hw->bytes_per_second) / ticks_per_sec; 49 50 if (bytes > INT_MAX) 51 samples = INT_MAX >> hw->shift; 52 else 53 samples = bytes >> hw->shift; 54 55 live = pcm_hw_get_live (hw); 56 if (live <= 0) 57 return; 58 59 no->old_ticks = now; 60 decr = audio_MIN (live, samples); 61 samples = decr; 62 rpos = hw->rpos; 63 while (samples) { 64 int left_till_end_samples = hw->samples - rpos; 65 int convert_samples = audio_MIN (samples, left_till_end_samples); 66 67 src = advance (hw->mix_buf, rpos * sizeof (st_sample_t)); 68 memset (src, 0, convert_samples * sizeof (st_sample_t)); 69 70 rpos = (rpos + convert_samples) % hw->samples; 71 samples -= convert_samples; 72 } 73 74 pcm_hw_dec_live (hw, decr); 75 hw->rpos = rpos; 76 } 77 78 static int no_hw_write (SWVoice *sw, void *buf, int len) 79 { 80 return pcm_hw_write (sw, buf, len); 81 } 82 83 static int no_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt) 84 { 85 NoVoice *no = (NoVoice *) hw; 86 hw->freq = freq; 87 hw->nchannels = nchannels; 88 hw->fmt = fmt; 89 hw->bufsize = 4096; 90 return 0; 91 } 92 93 static void no_hw_fini (HWVoice *hw) 94 { 95 (void) hw; 96 } 97 98 static int no_hw_ctl (HWVoice *hw, int cmd, ...) 99 { 100 (void) hw; 101 (void) cmd; 102 return 0; 103 } 104 105 static void *no_audio_init (void) 106 { 107 return &no_audio_init; 108 } 109 110 static void no_audio_fini (void *opaque) 111 { 112 } 113 114 struct pcm_ops no_pcm_ops = { 115 no_hw_init, 116 no_hw_fini, 117 no_hw_run, 118 no_hw_write, 119 no_hw_ctl 120 }; 121 122 struct audio_output_driver no_output_driver = { 123 "none", 124 no_audio_init, 125 no_audio_fini, 126 &no_pcm_ops, 127 1, 128 1, 129 sizeof (NoVoice) 130 }; 131