d37bf24d90
Replaces the NATIVE_FREQUENCY constant with a configurable frequency. The user may select 48000Hz if the hardware supports it. The default is still 44100Hz and the minimum is 44100Hz. The setting is located in the playback settings, under "Frequency". "Frequency" was duplicated in english.lang for now to avoid having to fix every .lang file for the moment and throwing everything out of sync because of the new play_frequency feature in features.txt. The next cleanup should combine it with the one included for recording and generalize the ID label. If the hardware doesn't support 48000Hz, no setting will be available. On particular hardware where very high rates are practical and desireable, the upper bound can be extended by patching. The PCM mixer can be configured to play at the full hardware frequency range. The DSP core can configure to the hardware minimum up to the maximum playback setting (some buffers must be reserved according to the maximum rate). If only 44100Hz is supported or possible on a given target for playback, using the DSP and mixer at other samperates is possible if the hardware offers them. Change-Id: I6023cf0c0baa8bc6292b6919b4dd3618a6a25622 Reviewed-on: http://gerrit.rockbox.org/479 Reviewed-by: Michael Sevakis <jethead71@rockbox.org> Tested-by: Michael Sevakis <jethead71@rockbox.org>
104 lines
3.6 KiB
C
104 lines
3.6 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (c) 2011 Michael Sevakis
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "config.h"
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#include "system.h"
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#include "settings.h"
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#include "pcm.h"
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#include "pcm_mixer.h"
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#include "misc.h"
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#include "fixedpoint.h"
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/** Beep generation, CPU optimized **/
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#include "asm/beep.c"
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static uint32_t beep_phase; /* Phase of square wave generator */
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static uint32_t beep_step; /* Step of square wave generator on each sample */
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#ifdef BEEP_GENERIC
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static int16_t beep_amplitude; /* Amplitude of square wave generator */
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#else
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/* Optimized routines do XOR with phase sign bit in both channels at once */
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static uint32_t beep_amplitude; /* Amplitude of square wave generator */
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#endif
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static int beep_count; /* Number of samples remaining to generate */
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#define BEEP_COUNT(fs, duration) ((fs) / 1000 * (duration))
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/* Reserve enough static space for keyclick to fit in worst case */
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#define BEEP_BUF_COUNT BEEP_COUNT(PLAY_SAMPR_MAX, KEYCLICK_DURATION)
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static int16_t beep_buf[BEEP_BUF_COUNT*2] IBSS_ATTR __attribute__((aligned(4)));
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/* Callback to generate the beep frames - also don't want inlining of
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call below in beep_play */
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static void __attribute__((noinline))
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beep_get_more(const void **start, size_t *size)
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{
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int count = beep_count;
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if (count > 0)
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{
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count = MIN(count, BEEP_BUF_COUNT);
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beep_count -= count;
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*start = beep_buf;
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*size = count * 2 * sizeof (int16_t);
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beep_generate((void *)beep_buf, count, &beep_phase,
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beep_step, beep_amplitude);
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}
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}
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/* Generates a constant square wave sound with a given frequency in Hertz for
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a duration in milliseconds */
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void beep_play(unsigned int frequency, unsigned int duration,
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unsigned int amplitude)
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{
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mixer_channel_stop(PCM_MIXER_CHAN_BEEP);
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if (frequency == 0 || duration == 0 || amplitude == 0)
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return;
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if (amplitude > INT16_MAX)
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amplitude = INT16_MAX;
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/* Setup the parameters for the square wave generator */
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uint32_t fout = mixer_get_frequency();
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beep_phase = 0;
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beep_step = fp_div(frequency, fout, 32);
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beep_count = BEEP_COUNT(fout, duration);
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#ifdef BEEP_GENERIC
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beep_amplitude = amplitude;
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#else
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/* Optimized routines do XOR with phase sign bit in both channels at once */
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beep_amplitude = amplitude | (amplitude << 16); /* Word:|AMP16|AMP16| */
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#endif
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/* If it fits - avoid cb overhead */
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const void *start;
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size_t size;
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/* Generate first frame here */
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beep_get_more(&start, &size);
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mixer_channel_set_amplitude(PCM_MIXER_CHAN_BEEP, MIX_AMP_UNITY);
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mixer_channel_play_data(PCM_MIXER_CHAN_BEEP,
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beep_count ? beep_get_more : NULL,
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start, size);
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}
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