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Create rate converter plugin SDK
Created a new rate converter plugin SDK. A rate converter can be replaced as an extra plugin now. The default rate converter is a built-in linear converter. You can find a sample external converter in alsa-plugins package.
This commit is contained in:
Takashi Iwai
parent
8f605df24a
commit
33d69ef33b
8 changed files with 879 additions and 461 deletions
435
src/pcm/pcm_rate_linear.c
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435
src/pcm/pcm_rate_linear.c
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@ -0,0 +1,435 @@
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/*
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* Linear rate converter plugin
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*
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* Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
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* 2004 by Jaroslav Kysela <perex@suse.cz>
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* 2006 by Takashi Iwai <tiwai@suse.de>
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <inttypes.h>
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#include <byteswap.h>
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#include "pcm_local.h"
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#include "pcm_plugin.h"
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#include "pcm_rate.h"
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#include "plugin_ops.h"
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/* LINEAR_DIV needs to be large enough to handle resampling from 192000 -> 8000 */
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#define LINEAR_DIV_SHIFT 19
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#define LINEAR_DIV (1<<LINEAR_DIV_SHIFT)
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struct rate_linear {
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unsigned int get_idx;
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unsigned int put_idx;
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unsigned int pitch;
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unsigned int pitch_shift; /* for expand interpolation */
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unsigned int channels;
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int16_t *old_sample;
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void (*func)(struct rate_linear *rate,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames);
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};
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static snd_pcm_uframes_t input_frames(void *obj, snd_pcm_uframes_t frames)
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{
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struct rate_linear *rate = obj;
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if (frames == 0)
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return 0;
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/* Round toward zero */
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return muldiv_near(frames, LINEAR_DIV, rate->pitch);
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}
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static snd_pcm_uframes_t output_frames(void *obj, snd_pcm_uframes_t frames)
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{
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struct rate_linear *rate = obj;
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if (frames == 0)
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return 0;
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/* Round toward zero */
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return muldiv_near(frames, rate->pitch, LINEAR_DIV);
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}
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static void linear_expand(struct rate_linear *rate,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames)
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{
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#define GET16_LABELS
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#define PUT16_LABELS
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#include "plugin_ops.h"
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#undef GET16_LABELS
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#undef PUT16_LABELS
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void *get = get16_labels[rate->get_idx];
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void *put = put16_labels[rate->put_idx];
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unsigned int get_threshold = rate->pitch;
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unsigned int channel;
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unsigned int src_frames1;
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unsigned int dst_frames1;
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int16_t sample = 0;
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unsigned int pos;
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for (channel = 0; channel < rate->channels; ++channel) {
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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const char *src;
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char *dst;
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int src_step, dst_step;
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int16_t old_sample = 0;
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int16_t new_sample;
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int old_weight, new_weight;
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area);
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dst_step = snd_pcm_channel_area_step(dst_area);
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src_frames1 = 0;
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dst_frames1 = 0;
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new_sample = rate->old_sample[channel];
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pos = get_threshold;
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while (dst_frames1 < dst_frames) {
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if (pos >= get_threshold) {
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pos -= get_threshold;
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old_sample = new_sample;
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if (src_frames1 < src_frames) {
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goto *get;
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#define GET16_END after_get
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#include "plugin_ops.h"
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#undef GET16_END
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after_get:
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new_sample = sample;
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}
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}
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new_weight = (pos << (16 - rate->pitch_shift)) / (get_threshold >> rate->pitch_shift);
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old_weight = 0x10000 - new_weight;
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sample = (old_sample * old_weight + new_sample * new_weight) >> 16;
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goto *put;
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#define PUT16_END after_put
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#include "plugin_ops.h"
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#undef PUT16_END
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after_put:
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dst += dst_step;
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dst_frames1++;
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pos += LINEAR_DIV;
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if (pos >= get_threshold) {
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src += src_step;
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src_frames1++;
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}
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}
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rate->old_sample[channel] = new_sample;
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}
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}
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/* optimized version for S16 format */
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static void linear_expand_s16(struct rate_linear *rate,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames)
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{
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unsigned int channel;
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unsigned int src_frames1;
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unsigned int dst_frames1;
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unsigned int get_threshold = rate->pitch;
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unsigned int pos;
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for (channel = 0; channel < rate->channels; ++channel) {
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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const int16_t *src;
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int16_t *dst;
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int src_step, dst_step;
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int16_t old_sample = 0;
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int16_t new_sample;
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int old_weight, new_weight;
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area) >> 1;
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dst_step = snd_pcm_channel_area_step(dst_area) >> 1;
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src_frames1 = 0;
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dst_frames1 = 0;
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new_sample = rate->old_sample[channel];
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pos = get_threshold;
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while (dst_frames1 < dst_frames) {
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if (pos >= get_threshold) {
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pos -= get_threshold;
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old_sample = new_sample;
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if (src_frames1 < src_frames)
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new_sample = *src;
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}
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new_weight = (pos << (16 - rate->pitch_shift)) / (get_threshold >> rate->pitch_shift);
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old_weight = 0x10000 - new_weight;
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*dst = (old_sample * old_weight + new_sample * new_weight) >> 16;
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dst += dst_step;
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dst_frames1++;
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pos += LINEAR_DIV;
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if (pos >= get_threshold) {
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src += src_step;
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src_frames1++;
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}
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}
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rate->old_sample[channel] = new_sample;
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}
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}
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static void linear_shrink(struct rate_linear *rate,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames)
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{
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#define GET16_LABELS
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#define PUT16_LABELS
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#include "plugin_ops.h"
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#undef GET16_LABELS
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#undef PUT16_LABELS
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void *get = get16_labels[rate->get_idx];
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void *put = put16_labels[rate->put_idx];
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unsigned int get_increment = rate->pitch;
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unsigned int channel;
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unsigned int src_frames1;
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unsigned int dst_frames1;
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int16_t sample = 0;
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unsigned int pos;
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for (channel = 0; channel < rate->channels; ++channel) {
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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const char *src;
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char *dst;
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int src_step, dst_step;
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int16_t old_sample = 0;
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int16_t new_sample = 0;
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int old_weight, new_weight;
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pos = LINEAR_DIV - get_increment; /* Force first sample to be copied */
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area);
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dst_step = snd_pcm_channel_area_step(dst_area);
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src_frames1 = 0;
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dst_frames1 = 0;
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while (src_frames1 < src_frames) {
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goto *get;
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#define GET16_END after_get
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#include "plugin_ops.h"
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#undef GET16_END
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after_get:
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new_sample = sample;
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src += src_step;
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src_frames1++;
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pos += get_increment;
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if (pos >= LINEAR_DIV) {
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pos -= LINEAR_DIV;
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old_weight = (pos << (32 - LINEAR_DIV_SHIFT)) / (get_increment >> (LINEAR_DIV_SHIFT - 16));
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new_weight = 0x10000 - old_weight;
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sample = (old_sample * old_weight + new_sample * new_weight) >> 16;
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goto *put;
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#define PUT16_END after_put
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#include "plugin_ops.h"
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#undef PUT16_END
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after_put:
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dst += dst_step;
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dst_frames1++;
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if (CHECK_SANITY(dst_frames1 > dst_frames)) {
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SNDERR("dst_frames overflow");
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break;
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}
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}
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old_sample = new_sample;
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}
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}
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}
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/* optimized version for S16 format */
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static void linear_shrink_s16(struct rate_linear *rate,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames)
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{
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unsigned int get_increment = rate->pitch;
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unsigned int channel;
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unsigned int src_frames1;
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unsigned int dst_frames1;
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unsigned int pos = 0;
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for (channel = 0; channel < rate->channels; ++channel) {
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const snd_pcm_channel_area_t *src_area = &src_areas[channel];
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const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
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const int16_t *src;
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int16_t *dst;
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int src_step, dst_step;
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int16_t old_sample = 0;
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int16_t new_sample = 0;
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int old_weight, new_weight;
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pos = LINEAR_DIV - get_increment; /* Force first sample to be copied */
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src = snd_pcm_channel_area_addr(src_area, src_offset);
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dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
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src_step = snd_pcm_channel_area_step(src_area) >> 1;
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dst_step = snd_pcm_channel_area_step(dst_area) >> 1 ;
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src_frames1 = 0;
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dst_frames1 = 0;
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while (src_frames1 < src_frames) {
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new_sample = *src;
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src += src_step;
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src_frames1++;
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pos += get_increment;
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if (pos >= LINEAR_DIV) {
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pos -= LINEAR_DIV;
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old_weight = (pos << (32 - LINEAR_DIV_SHIFT)) / (get_increment >> (LINEAR_DIV_SHIFT - 16));
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new_weight = 0x10000 - old_weight;
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*dst = (old_sample * old_weight + new_sample * new_weight) >> 16;
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dst += dst_step;
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dst_frames1++;
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if (CHECK_SANITY(dst_frames1 > dst_frames)) {
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SNDERR("dst_frames overflow");
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break;
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}
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}
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old_sample = new_sample;
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}
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}
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}
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static void linear_convert(void *obj,
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const snd_pcm_channel_area_t *dst_areas,
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snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
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const snd_pcm_channel_area_t *src_areas,
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snd_pcm_uframes_t src_offset, unsigned int src_frames)
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{
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struct rate_linear *rate = obj;
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rate->func(rate, dst_areas, dst_offset, dst_frames,
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src_areas, src_offset, src_frames);
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}
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static void linear_free(void *obj)
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{
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struct rate_linear *rate = obj;
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free(rate->old_sample);
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rate->old_sample = NULL;
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}
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static int linear_init(void *obj, snd_pcm_rate_info_t *info)
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{
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struct rate_linear *rate = obj;
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rate->get_idx = snd_pcm_linear_get_index(info->in.format, SND_PCM_FORMAT_S16);
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rate->put_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S16, info->out.format);
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if (info->in.rate < info->out.rate) {
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if (info->in.format == info->out.format && info->in.format == SND_PCM_FORMAT_S16)
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rate->func = linear_expand_s16;
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else
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rate->func = linear_expand;
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/* pitch is get_threshold */
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} else {
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if (info->in.format == info->out.format && info->in.format == SND_PCM_FORMAT_S16)
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rate->func = linear_shrink_s16;
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else
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rate->func = linear_shrink;
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/* pitch is get_increment */
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}
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rate->pitch = (((u_int64_t)info->out.rate * LINEAR_DIV) +
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(info->in.rate / 2)) / info->in.rate;
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rate->channels = info->channels;
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free(rate->old_sample);
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rate->old_sample = malloc(sizeof(*rate->old_sample) * rate->channels);
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if (! rate->old_sample)
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return -ENOMEM;
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return 0;
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}
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static int linear_adjust_pitch(void *obj, snd_pcm_rate_info_t *info)
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{
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struct rate_linear *rate = obj;
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snd_pcm_uframes_t cframes;
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rate->pitch = (((u_int64_t)info->out.period_size * LINEAR_DIV) +
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(info->in.period_size/2) ) / info->in.period_size;
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cframes = input_frames(rate, info->out.period_size);
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while (cframes != info->in.period_size) {
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snd_pcm_uframes_t cframes_new;
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if (cframes > info->in.period_size)
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rate->pitch++;
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else
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rate->pitch--;
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cframes_new = input_frames(rate, info->out.period_size);
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if ((cframes > info->in.period_size && cframes_new < info->in.period_size) ||
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(cframes < info->in.period_size && cframes_new > info->in.period_size)) {
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SNDERR("invalid pcm period_size %ld -> %ld",
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info->in.period_size, info->out.period_size);
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return -EIO;
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}
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cframes = cframes_new;
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}
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if (rate->pitch >= LINEAR_DIV) {
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/* shift for expand linear interpolation */
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rate->pitch_shift = 0;
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while ((rate->pitch >> rate->pitch_shift) >= (1 << 16))
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rate->pitch_shift++;
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}
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return 0;
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}
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static void linear_reset(void *obj)
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{
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struct rate_linear *rate = obj;
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/* for expand */
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if (rate->old_sample)
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memset(rate->old_sample, 0, sizeof(*rate->old_sample) * rate->channels);
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}
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static void linear_close(void *obj)
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{
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free(obj);
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}
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static snd_pcm_rate_ops_t linear_ops = {
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.close = linear_close,
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.init = linear_init,
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.free = linear_free,
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.reset = linear_reset,
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.adjust_pitch = linear_adjust_pitch,
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.convert = linear_convert,
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.input_frames = input_frames,
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.output_frames = output_frames,
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};
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int SND_PCM_RATE_PLUGIN_ENTRY(linear) (unsigned int version, void **objp, snd_pcm_rate_ops_t *ops)
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{
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struct rate_linear *rate;
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if (version != SND_PCM_RATE_PLUGIN_VERSION) {
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SNDERR("Invalid plugin version %x\n", version);
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return -EINVAL;
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}
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rate = calloc(1, sizeof(*rate));
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if (! rate)
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return -ENOMEM;
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*objp = rate;
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*ops = linear_ops;
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return 0;
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}
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