--- /dev/null
+/*
+ * Fast implementation of greatest common divisor using the binary algorithm.
+ * Copyright (c) 2007 Nicholas Kain
+ *
+ * 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.
+ */
+
+/* computes gcd using binary algorithm */
+static int gcd(int a, int b)
+{
+ int s,d;
+
+ if (!a || !b)
+ return a | b;
+
+ for (s=0; ((a|b)&1) == 0; ++s) {
+ a >>= 1;
+ b >>= 1;
+ }
+
+ while ((a&1) == 0)
+ a >>= 1;
+
+ do {
+ while ((b&1) == 0) {
+ b >>= 1;
+ }
+ if (a<b) {
+ b -= a;
+ } else {
+ d = a-b;
+ a = b;
+ b = d;
+ }
+ b >>= 1;
+ } while (b);
+
+ return a << s;
+}
+
--- /dev/null
+/*
+ * Rate converter plugin using libavcodec's resampler
+ * Copyright (c) 2007 by Nicholas Kain <njkain@gmail.com>
+ *
+ * based on rate converter that uses libsamplerate
+ * Copyright (c) 2006 by Takashi Iwai <tiwai@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#include <stdio.h>
+#include <alsa/asoundlib.h>
+#include <alsa/pcm_rate.h>
+#include <ffmpeg/avcodec.h>
+#include "gcd.h"
+
+static int filter_size = 16;
+static int phase_shift = 10; /* auto-adjusts */
+static double cutoff = 0; /* auto-adjusts */
+
+struct rate_src {
+ struct AVResampleContext *context;
+ int in_rate;
+ int out_rate;
+ int stored;
+ int point;
+ int16_t **out;
+ int16_t **in;
+ unsigned int channels;
+};
+
+static snd_pcm_uframes_t input_frames(void *obj, snd_pcm_uframes_t frames)
+{
+ return frames;
+}
+
+static snd_pcm_uframes_t output_frames(void *obj, snd_pcm_uframes_t frames)
+{
+ return frames;
+}
+
+static void pcm_src_free(void *obj)
+{
+ struct rate_src *rate = obj;
+ int i;
+
+ if (rate->out) {
+ for (i=0; i<rate->channels; i++) {
+ free(rate->out[i]);
+ }
+ free(rate->out);
+ }
+ if (rate->in) {
+ for (i=0; i<rate->channels; i++) {
+ free(rate->in[i]);
+ }
+ free(rate->in);
+ }
+ rate->out = rate->in = NULL;
+
+ if (rate->context) {
+ av_resample_close(rate->context);
+ rate->context = NULL;
+ }
+}
+
+static int pcm_src_init(void *obj, snd_pcm_rate_info_t *info)
+{
+ struct rate_src *rate = obj;
+ int i, ir, or;
+
+ if (! rate->context || rate->channels != info->channels) {
+ pcm_src_free(rate);
+ rate->channels = info->channels;
+ ir = rate->in_rate = info->in.rate;
+ or = rate->out_rate = info->out.rate;
+ i = gcd(or, ir);
+ if (or > ir) {
+ phase_shift = or/i;
+ } else {
+ phase_shift = ir/i;
+ }
+ if (cutoff <= 0.0) {
+ cutoff = 1.0 - 1.0/filter_size;
+ if (cutoff < 0.80)
+ cutoff = 0.80;
+ }
+ rate->context = av_resample_init(info->out.rate, info->in.rate,
+ filter_size, phase_shift,
+ (info->out.rate >= info->in.rate ? 0 : 1), cutoff);
+ if (!rate->context)
+ return -EINVAL;
+ }
+
+ rate->out = malloc(rate->channels * sizeof(int16_t *));
+ rate->in = malloc(rate->channels * sizeof(int16_t *));
+ for (i=0; i<rate->channels; i++) {
+ rate->out[i] = calloc(info->out.period_size * 2,
+ sizeof(int16_t));
+ rate->in[i] = calloc(info->in.period_size * 2,
+ sizeof(int16_t));
+ }
+ rate->point = info->in.period_size / 2;
+ if (!rate->out || !rate->in) {
+ pcm_src_free(rate);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int pcm_src_adjust_pitch(void *obj, snd_pcm_rate_info_t *info)
+{
+ struct rate_src *rate = obj;
+
+ if (info->out.rate != rate->out_rate || info->in.rate != rate->in_rate)
+ pcm_src_init(obj, info);
+ return 0;
+}
+
+static void pcm_src_reset(void *obj)
+{
+ struct rate_src *rate = obj;
+ rate->stored = 0;
+}
+
+static void deinterleave(const int16_t *src, int16_t **dst, unsigned int frames,
+ unsigned int chans, int overflow)
+{
+ int i, j;
+
+ if (chans == 1) {
+ memcpy(dst + overflow, src, frames*sizeof(int16_t));
+ } else if (chans == 2) {
+ for (j=overflow; j<(frames + overflow); j++) {
+ dst[0][j] = *(src++);
+ dst[1][j] = *(src++);
+ }
+ } else {
+ for (j=overflow; j<(frames + overflow); j++) {
+ for (i=0; i<chans; i++) {
+ dst[i][j] = *(src++);
+ }
+ }
+ }
+}
+
+static void reinterleave(int16_t **src, int16_t *dst, unsigned int frames,
+ unsigned int chans)
+{
+ int i, j;
+
+ if (chans == 1) {
+ memcpy(dst, src, frames*sizeof(int16_t));
+ } else if (chans == 2) {
+ for (j=0; j<frames; j++) {
+ *(dst++) = src[0][j];
+ *(dst++) = src[1][j];
+ }
+ } else {
+ for (j=0; j<frames; j++) {
+ for (i=0; i<chans; i++) {
+ *(dst++) = src[i][j];
+ }
+ }
+ }
+}
+
+static void pcm_src_convert_s16(void *obj, int16_t *dst, unsigned int
+ dst_frames, const int16_t *src, unsigned int src_frames)
+{
+ struct rate_src *rate = obj;
+ int consumed = 0, chans=rate->channels, ret=0, i;
+ int total_in = rate->stored + src_frames, new_stored;
+
+ deinterleave(src, rate->in, src_frames, chans, rate->point);
+ for (i=0; i<chans; ++i) {
+ ret = av_resample(rate->context, rate->out[i],
+ rate->in[i]+rate->point-rate->stored, &consumed,
+ total_in, dst_frames, i == (chans - 1));
+ new_stored = total_in-consumed;
+ memmove(rate->in[i]+rate->point-new_stored,
+ rate->in[i]+rate->point-rate->stored+consumed,
+ new_stored*sizeof(int16_t));
+ }
+ av_resample_compensate(rate->context,
+ total_in-src_frames>filter_size?0:1, src_frames);
+ reinterleave(rate->out, dst, ret, chans);
+ rate->stored = total_in-consumed;
+}
+
+static void pcm_src_close(void *obj)
+{
+ pcm_src_free(obj);
+}
+
+static snd_pcm_rate_ops_t pcm_src_ops = {
+ .close = pcm_src_close,
+ .init = pcm_src_init,
+ .free = pcm_src_free,
+ .reset = pcm_src_reset,
+ .adjust_pitch = pcm_src_adjust_pitch,
+ .convert_s16 = pcm_src_convert_s16,
+ .input_frames = input_frames,
+ .output_frames = output_frames,
+};
+
+int pcm_src_open(unsigned int version, void **objp, snd_pcm_rate_ops_t *ops)
+
+{
+ struct rate_src *rate;
+
+ if (version != SND_PCM_RATE_PLUGIN_VERSION) {
+ fprintf(stderr, "Invalid rate plugin version %x\n", version);
+ return -EINVAL;
+ }
+
+ rate = calloc(1, sizeof(*rate));
+ if (!rate)
+ return -ENOMEM;
+
+ *objp = rate;
+ rate->context = NULL;
+ *ops = pcm_src_ops;
+ return 0;
+}
+
+int SND_PCM_RATE_PLUGIN_ENTRY(lavcrate)(unsigned int version, void **objp,
+ snd_pcm_rate_ops_t *ops)
+{
+ return pcm_src_open(version, objp, ops);
+}
+int SND_PCM_RATE_PLUGIN_ENTRY(lavcrate_higher)(unsigned int version,
+ void **objp, snd_pcm_rate_ops_t *ops)
+{
+ filter_size = 64;
+ return pcm_src_open(version, objp, ops);
+}
+int SND_PCM_RATE_PLUGIN_ENTRY(lavcrate_high)(unsigned int version,
+ void **objp, snd_pcm_rate_ops_t *ops)
+{
+ filter_size = 32;
+ return pcm_src_open(version, objp, ops);
+}
+int SND_PCM_RATE_PLUGIN_ENTRY(lavcrate_fast)(unsigned int version,
+ void **objp, snd_pcm_rate_ops_t *ops)
+{
+ filter_size = 8;
+ return pcm_src_open(version, objp, ops);
+}
+int SND_PCM_RATE_PLUGIN_ENTRY(lavcrate_faster)(unsigned int version,
+ void **objp, snd_pcm_rate_ops_t *ops)
+{
+ filter_size = 4;
+ return pcm_src_open(version, objp, ops);
+}
+
+
git://git.alsa-project.org / alsa-plugins.git / commitdiff