9833438ef6
Commit ff095e5231 "audio: api for mixeng code free backends"
introduced another FIFO for the audio subsystem with exactly the
same size as the mixing-engine FIFO. Most audio backends use
this generic FIFO. The generic FIFO used together with the
mixing-engine FIFO doubles the audio FIFO size, because that's
just two independent FIFOs connected together in series.
For audio playback this nearly doubles the playback latency.
This patch restores the effective mixing-engine playback buffer
size to a pre v4.2.0 size by only accepting the amount of
samples for the mixing-engine queue which the downstream queue
accepts.
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20220301191311.26695-10-vr_qemu@t-online.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
150 lines
3.9 KiB
C
150 lines
3.9 KiB
C
/*
|
|
* QEMU Timer based audio emulation
|
|
*
|
|
* Copyright (c) 2004-2005 Vassili Karpov (malc)
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu/host-utils.h"
|
|
#include "qemu/module.h"
|
|
#include "audio.h"
|
|
#include "qemu/timer.h"
|
|
|
|
#define AUDIO_CAP "noaudio"
|
|
#include "audio_int.h"
|
|
|
|
typedef struct NoVoiceOut {
|
|
HWVoiceOut hw;
|
|
RateCtl rate;
|
|
} NoVoiceOut;
|
|
|
|
typedef struct NoVoiceIn {
|
|
HWVoiceIn hw;
|
|
RateCtl rate;
|
|
} NoVoiceIn;
|
|
|
|
static size_t no_write(HWVoiceOut *hw, void *buf, size_t len)
|
|
{
|
|
NoVoiceOut *no = (NoVoiceOut *) hw;
|
|
return audio_rate_get_bytes(&hw->info, &no->rate, len);
|
|
}
|
|
|
|
static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
|
|
{
|
|
NoVoiceOut *no = (NoVoiceOut *) hw;
|
|
|
|
audio_pcm_init_info (&hw->info, as);
|
|
hw->samples = 1024;
|
|
audio_rate_start(&no->rate);
|
|
return 0;
|
|
}
|
|
|
|
static void no_fini_out (HWVoiceOut *hw)
|
|
{
|
|
(void) hw;
|
|
}
|
|
|
|
static void no_enable_out(HWVoiceOut *hw, bool enable)
|
|
{
|
|
NoVoiceOut *no = (NoVoiceOut *) hw;
|
|
|
|
if (enable) {
|
|
audio_rate_start(&no->rate);
|
|
}
|
|
}
|
|
|
|
static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
|
|
{
|
|
NoVoiceIn *no = (NoVoiceIn *) hw;
|
|
|
|
audio_pcm_init_info (&hw->info, as);
|
|
hw->samples = 1024;
|
|
audio_rate_start(&no->rate);
|
|
return 0;
|
|
}
|
|
|
|
static void no_fini_in (HWVoiceIn *hw)
|
|
{
|
|
(void) hw;
|
|
}
|
|
|
|
static size_t no_read(HWVoiceIn *hw, void *buf, size_t size)
|
|
{
|
|
NoVoiceIn *no = (NoVoiceIn *) hw;
|
|
int64_t bytes = audio_rate_get_bytes(&hw->info, &no->rate, size);
|
|
|
|
audio_pcm_info_clear_buf(&hw->info, buf, bytes / hw->info.bytes_per_frame);
|
|
return bytes;
|
|
}
|
|
|
|
static void no_enable_in(HWVoiceIn *hw, bool enable)
|
|
{
|
|
NoVoiceIn *no = (NoVoiceIn *) hw;
|
|
|
|
if (enable) {
|
|
audio_rate_start(&no->rate);
|
|
}
|
|
}
|
|
|
|
static void *no_audio_init(Audiodev *dev)
|
|
{
|
|
return &no_audio_init;
|
|
}
|
|
|
|
static void no_audio_fini (void *opaque)
|
|
{
|
|
(void) opaque;
|
|
}
|
|
|
|
static struct audio_pcm_ops no_pcm_ops = {
|
|
.init_out = no_init_out,
|
|
.fini_out = no_fini_out,
|
|
.write = no_write,
|
|
.buffer_get_free = audio_generic_buffer_get_free,
|
|
.run_buffer_out = audio_generic_run_buffer_out,
|
|
.enable_out = no_enable_out,
|
|
|
|
.init_in = no_init_in,
|
|
.fini_in = no_fini_in,
|
|
.read = no_read,
|
|
.run_buffer_in = audio_generic_run_buffer_in,
|
|
.enable_in = no_enable_in
|
|
};
|
|
|
|
static struct audio_driver no_audio_driver = {
|
|
.name = "none",
|
|
.descr = "Timer based audio emulation",
|
|
.init = no_audio_init,
|
|
.fini = no_audio_fini,
|
|
.pcm_ops = &no_pcm_ops,
|
|
.can_be_default = 1,
|
|
.max_voices_out = INT_MAX,
|
|
.max_voices_in = INT_MAX,
|
|
.voice_size_out = sizeof (NoVoiceOut),
|
|
.voice_size_in = sizeof (NoVoiceIn)
|
|
};
|
|
|
|
static void register_audio_none(void)
|
|
{
|
|
audio_driver_register(&no_audio_driver);
|
|
}
|
|
type_init(register_audio_none);
|