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
  25 #include "qemu/osdep.h"
  26 #include "qemu/host-utils.h"
  27 #include "qemu/module.h"
  28 #include "audio.h"
  29 #include "qemu/timer.h"
  30
  31 #define AUDIO_CAP "noaudio"
  32 #include "audio_int.h"
  33
  34 typedef struct NoVoiceOut {
  35     HWVoiceOut hw;
  36     int64_t old_ticks;
  37 } NoVoiceOut;
  38
  39 typedef struct NoVoiceIn {
  40     HWVoiceIn hw;
  41     int64_t old_ticks;
  42 } NoVoiceIn;
  43
  44 static size_t no_run_out(HWVoiceOut *hw, size_t live)
  45 {
  46     NoVoiceOut *no = (NoVoiceOut *) hw;
  47     size_t decr, samples;
  48     int64_t now;
  49     int64_t ticks;
  50     int64_t bytes;
  51
  52     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  53     ticks = now - no->old_ticks;
  54     bytes = muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
  55     bytes = MIN(bytes, SIZE_MAX);
  56     samples = bytes >> hw->info.shift;
  57
  58     no->old_ticks = now;
  59     decr = MIN (live, samples);
  60     hw->rpos = (hw->rpos + decr) % hw->samples;
  61     return decr;
  62 }
  63
  64 static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
  65 {
  66     audio_pcm_init_info (&hw->info, as);
  67     hw->samples = 1024;
  68     return 0;
  69 }
  70
  71 static void no_fini_out (HWVoiceOut *hw)
  72 {
  73     (void) hw;
  74 }
  75
  76 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
  77 {
  78     (void) hw;
  79     (void) cmd;
  80     return 0;
  81 }
  82
  83 static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
  84 {
  85     audio_pcm_init_info (&hw->info, as);
  86     hw->samples = 1024;
  87     return 0;
  88 }
  89
  90 static void no_fini_in (HWVoiceIn *hw)
  91 {
  92     (void) hw;
  93 }
  94
  95 static size_t no_run_in(HWVoiceIn *hw)
  96 {
  97     NoVoiceIn *no = (NoVoiceIn *) hw;
  98     size_t live = audio_pcm_hw_get_live_in(hw);
  99     size_t dead = hw->samples - live;
 100     size_t samples = 0;
 101
 102     if (dead) {
 103         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 104         int64_t ticks = now - no->old_ticks;
 105         int64_t bytes =
 106             muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
 107
 108         no->old_ticks = now;
 109         bytes = MIN (bytes, SIZE_MAX);
 110         samples = bytes >> hw->info.shift;
 111         samples = MIN (samples, dead);
 112     }
 113     return samples;
 114 }
 115
 116 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
 117 {
 118     (void) hw;
 119     (void) cmd;
 120     return 0;
 121 }
 122
 123 static void *no_audio_init(Audiodev *dev)
 124 {
 125     return &no_audio_init;
 126 }
 127
 128 static void no_audio_fini (void *opaque)
 129 {
 130     (void) opaque;
 131 }
 132
 133 static struct audio_pcm_ops no_pcm_ops = {
 134     .init_out = no_init_out,
 135     .fini_out = no_fini_out,
 136     .run_out  = no_run_out,
 137     .ctl_out  = no_ctl_out,
 138
 139     .init_in  = no_init_in,
 140     .fini_in  = no_fini_in,
 141     .run_in   = no_run_in,
 142     .ctl_in   = no_ctl_in
 143 };
 144
 145 static struct audio_driver no_audio_driver = {
 146     .name           = "none",
 147     .descr          = "Timer based audio emulation",
 148     .init           = no_audio_init,
 149     .fini           = no_audio_fini,
 150     .pcm_ops        = &no_pcm_ops,
 151     .can_be_default = 1,
 152     .max_voices_out = INT_MAX,
 153     .max_voices_in  = INT_MAX,
 154     .voice_size_out = sizeof (NoVoiceOut),
 155     .voice_size_in  = sizeof (NoVoiceIn)
 156 };
 157
 158 static void register_audio_none(void)
 159 {
 160     audio_driver_register(&no_audio_driver);
 161 }
 162 type_init(register_audio_none);