audio/noaudio.c

   1 /*
   2  * QEMU Timer based audio emulation
   3  *
   4  * Copyright (c) 2004-2005 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 "qemu-common.h"
  25 #include "audio.h"
  26 #include "qemu/timer.h"
  27
  28 #define AUDIO_CAP "noaudio"
  29 #include "audio_int.h"
  30
  31 typedef struct NoVoiceOut {
  32     HWVoiceOut hw;
  33     int64_t old_ticks;
  34 } NoVoiceOut;
  35
  36 typedef struct NoVoiceIn {
  37     HWVoiceIn hw;
  38     int64_t old_ticks;
  39 } NoVoiceIn;
  40
  41 static int no_run_out (HWVoiceOut *hw, int live)
  42 {
  43     NoVoiceOut *no = (NoVoiceOut *) hw;
  44     int decr, samples;
  45     int64_t now;
  46     int64_t ticks;
  47     int64_t bytes;
  48
  49     now = qemu_get_clock_ns (vm_clock);
  50     ticks = now - no->old_ticks;
  51     bytes = muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
  52     bytes = audio_MIN (bytes, INT_MAX);
  53     samples = bytes >> hw->info.shift;
  54
  55     no->old_ticks = now;
  56     decr = audio_MIN (live, samples);
  57     hw->rpos = (hw->rpos + decr) % hw->samples;
  58     return decr;
  59 }
  60
  61 static int no_write (SWVoiceOut *sw, void *buf, int len)
  62 {
  63     return audio_pcm_sw_write (sw, buf, len);
  64 }
  65
  66 static int no_init_out (HWVoiceOut *hw, struct audsettings *as)
  67 {
  68     audio_pcm_init_info (&hw->info, as);
  69     hw->samples = 1024;
  70     return 0;
  71 }
  72
  73 static void no_fini_out (HWVoiceOut *hw)
  74 {
  75     (void) hw;
  76 }
  77
  78 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
  79 {
  80     (void) hw;
  81     (void) cmd;
  82     return 0;
  83 }
  84
  85 static int no_init_in (HWVoiceIn *hw, struct audsettings *as)
  86 {
  87     audio_pcm_init_info (&hw->info, as);
  88     hw->samples = 1024;
  89     return 0;
  90 }
  91
  92 static void no_fini_in (HWVoiceIn *hw)
  93 {
  94     (void) hw;
  95 }
  96
  97 static int no_run_in (HWVoiceIn *hw)
  98 {
  99     NoVoiceIn *no = (NoVoiceIn *) hw;
 100     int live = audio_pcm_hw_get_live_in (hw);
 101     int dead = hw->samples - live;
 102     int samples = 0;
 103
 104     if (dead) {
 105         int64_t now = qemu_get_clock_ns (vm_clock);
 106         int64_t ticks = now - no->old_ticks;
 107         int64_t bytes =
 108             muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
 109
 110         no->old_ticks = now;
 111         bytes = audio_MIN (bytes, INT_MAX);
 112         samples = bytes >> hw->info.shift;
 113         samples = audio_MIN (samples, dead);
 114     }
 115     return samples;
 116 }
 117
 118 static int no_read (SWVoiceIn *sw, void *buf, int size)
 119 {
 120     /* use custom code here instead of audio_pcm_sw_read() to avoid
 121      * useless resampling/mixing */
 122     int samples = size >> sw->info.shift;
 123     int total = sw->hw->total_samples_captured - sw->total_hw_samples_acquired;
 124     int to_clear = audio_MIN (samples, total);
 125     sw->total_hw_samples_acquired += total;
 126     audio_pcm_info_clear_buf (&sw->info, buf, to_clear);
 127     return to_clear << sw->info.shift;
 128 }
 129
 130 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
 131 {
 132     (void) hw;
 133     (void) cmd;
 134     return 0;
 135 }
 136
 137 static void *no_audio_init (void)
 138 {
 139     return &no_audio_init;
 140 }
 141
 142 static void no_audio_fini (void *opaque)
 143 {
 144     (void) opaque;
 145 }
 146
 147 static struct audio_pcm_ops no_pcm_ops = {
 148     .init_out = no_init_out,
 149     .fini_out = no_fini_out,
 150     .run_out  = no_run_out,
 151     .write    = no_write,
 152     .ctl_out  = no_ctl_out,
 153
 154     .init_in  = no_init_in,
 155     .fini_in  = no_fini_in,
 156     .run_in   = no_run_in,
 157     .read     = no_read,
 158     .ctl_in   = no_ctl_in
 159 };
 160
 161 struct audio_driver no_audio_driver = {
 162     .name           = "none",
 163     .descr          = "Timer based audio emulation",
 164     .options        = NULL,
 165     .init           = no_audio_init,
 166     .fini           = no_audio_fini,
 167     .pcm_ops        = &no_pcm_ops,
 168     .can_be_default = 1,
 169     .max_voices_out = INT_MAX,
 170     .max_voices_in  = INT_MAX,
 171     .voice_size_out = sizeof (NoVoiceOut),
 172     .voice_size_in  = sizeof (NoVoiceIn)
 173 };