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/osdep.h"
  25 #include "qemu-common.h"
  26 #include "audio.h"
  27 #include "qemu/timer.h"
  28
  29 #define AUDIO_CAP "noaudio"
  30 #include "audio_int.h"
  31
  32 typedef struct NoVoiceOut {
  33     HWVoiceOut hw;
  34     int64_t old_ticks;
  35 } NoVoiceOut;
  36
  37 typedef struct NoVoiceIn {
  38     HWVoiceIn hw;
  39     int64_t old_ticks;
  40 } NoVoiceIn;
  41
  42 static int no_run_out (HWVoiceOut *hw, int live)
  43 {
  44     NoVoiceOut *no = (NoVoiceOut *) hw;
  45     int decr, samples;
  46     int64_t now;
  47     int64_t ticks;
  48     int64_t bytes;
  49
  50     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  51     ticks = now - no->old_ticks;
  52     bytes = muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
  53     bytes = audio_MIN (bytes, INT_MAX);
  54     samples = bytes >> hw->info.shift;
  55
  56     no->old_ticks = now;
  57     decr = audio_MIN (live, samples);
  58     hw->rpos = (hw->rpos + decr) % hw->samples;
  59     return decr;
  60 }
  61
  62 static int no_write (SWVoiceOut *sw, void *buf, int len)
  63 {
  64     return audio_pcm_sw_write (sw, buf, len);
  65 }
  66
  67 static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
  68 {
  69     audio_pcm_init_info (&hw->info, as);
  70     hw->samples = 1024;
  71     return 0;
  72 }
  73
  74 static void no_fini_out (HWVoiceOut *hw)
  75 {
  76     (void) hw;
  77 }
  78
  79 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
  80 {
  81     (void) hw;
  82     (void) cmd;
  83     return 0;
  84 }
  85
  86 static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
  87 {
  88     audio_pcm_init_info (&hw->info, as);
  89     hw->samples = 1024;
  90     return 0;
  91 }
  92
  93 static void no_fini_in (HWVoiceIn *hw)
  94 {
  95     (void) hw;
  96 }
  97
  98 static int no_run_in (HWVoiceIn *hw)
  99 {
 100     NoVoiceIn *no = (NoVoiceIn *) hw;
 101     int live = audio_pcm_hw_get_live_in (hw);
 102     int dead = hw->samples - live;
 103     int samples = 0;
 104
 105     if (dead) {
 106         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 107         int64_t ticks = now - no->old_ticks;
 108         int64_t bytes =
 109             muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
 110
 111         no->old_ticks = now;
 112         bytes = audio_MIN (bytes, INT_MAX);
 113         samples = bytes >> hw->info.shift;
 114         samples = audio_MIN (samples, dead);
 115     }
 116     return samples;
 117 }
 118
 119 static int no_read (SWVoiceIn *sw, void *buf, int size)
 120 {
 121     /* use custom code here instead of audio_pcm_sw_read() to avoid
 122      * useless resampling/mixing */
 123     int samples = size >> sw->info.shift;
 124     int total = sw->hw->total_samples_captured - sw->total_hw_samples_acquired;
 125     int to_clear = audio_MIN (samples, total);
 126     sw->total_hw_samples_acquired += total;
 127     audio_pcm_info_clear_buf (&sw->info, buf, to_clear);
 128     return to_clear << sw->info.shift;
 129 }
 130
 131 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
 132 {
 133     (void) hw;
 134     (void) cmd;
 135     return 0;
 136 }
 137
 138 static void *no_audio_init (void)
 139 {
 140     return &no_audio_init;
 141 }
 142
 143 static void no_audio_fini (void *opaque)
 144 {
 145     (void) opaque;
 146 }
 147
 148 static struct audio_pcm_ops no_pcm_ops = {
 149     .init_out = no_init_out,
 150     .fini_out = no_fini_out,
 151     .run_out  = no_run_out,
 152     .write    = no_write,
 153     .ctl_out  = no_ctl_out,
 154
 155     .init_in  = no_init_in,
 156     .fini_in  = no_fini_in,
 157     .run_in   = no_run_in,
 158     .read     = no_read,
 159     .ctl_in   = no_ctl_in
 160 };
 161
 162 struct audio_driver no_audio_driver = {
 163     .name           = "none",
 164     .descr          = "Timer based audio emulation",
 165     .options        = NULL,
 166     .init           = no_audio_init,
 167     .fini           = no_audio_fini,
 168     .pcm_ops        = &no_pcm_ops,
 169     .can_be_default = 1,
 170     .max_voices_out = INT_MAX,
 171     .max_voices_in  = INT_MAX,
 172     .voice_size_out = sizeof (NoVoiceOut),
 173     .voice_size_in  = sizeof (NoVoiceIn)
 174 };