mirror of
https://gitlab.freedesktop.org/pipewire/pipewire.git
synced 2025-10-31 22:25:38 -04:00
1c6cb049ce
Add an empty.noise option that specifies the number of bits to use for noise when the input signal is pure silence. Some amplifiers can go into suspend mode pretty easily when they get pure silence. With empty.noise = 1, audioconvert will now generate a bitpattern that can keep those amplifiers alive, together with disabling suspend in the session manager. Fixes #705
79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/* Spa
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*
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* Copyright © 2022 Wim Taymans
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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#include <string.h>
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#include <stdio.h>
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#include <math.h>
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#include <spa/param/audio/format-utils.h>
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#include <spa/support/cpu.h>
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#include <spa/support/log.h>
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#include <spa/utils/defs.h>
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#include "noise-ops.h"
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typedef void (*noise_func_t) (struct noise *ns, void * SPA_RESTRICT dst[], uint32_t n_samples);
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static const struct noise_info {
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noise_func_t process;
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uint32_t cpu_flags;
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} noise_table[] =
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{
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{ noise_f32_c, 0 },
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};
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#define MATCH_CPU_FLAGS(a,b) ((a) == 0 || ((a) & (b)) == a)
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static const struct noise_info *find_noise_info(uint32_t cpu_flags)
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{
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size_t i;
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for (i = 0; i < SPA_N_ELEMENTS(noise_table); i++) {
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if (!MATCH_CPU_FLAGS(noise_table[i].cpu_flags, cpu_flags))
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continue;
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return &noise_table[i];
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}
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return NULL;
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}
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static void impl_noise_free(struct noise *ns)
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{
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ns->process = NULL;
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}
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int noise_init(struct noise *ns)
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{
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const struct noise_info *info;
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int i;
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info = find_noise_info(ns->cpu_flags);
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if (info == NULL)
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return -ENOTSUP;
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for (i = 0; i < NOISE_SIZE; i++)
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ns->tab[i] = (drand48() - 0.5) / (1 << ns->intensity);
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ns->free = impl_noise_free;
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ns->process = info->process;
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return 0;
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}
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