Add rate resampler plugin based on speex

Added another rate resampler plugin based on speex code.
Light weight and much better quality.

From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>

1 files changed, 162 insertions, 0 deletions

diff --git a/pph/rate_speexrate.c b/pph/rate_speexrate.c
new file mode 100644
index 0000000..07679b4
--- /dev/null
+++ b/pph/rate_speexrate.c
@@ -0,0 +1,162 @@
+/* Rate converter plugin using Public Parrot Hack
+   Copyright (C) 2007 Jean-Marc Valin
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+   1. Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+
+   2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+   3. The name of the author may not be used to endorse or promote products
+   derived from this software without specific prior written permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+   DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+   POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <stdio.h>
+#include <samplerate.h>
+#include <alsa/asoundlib.h>
+#include <alsa/pcm_rate.h>
+
+#include "speex_resampler.h"
+
+struct rate_src {
+	int quality;
+	unsigned int channels;
+        SpeexResamplerState *st;
+};
+
+static snd_pcm_uframes_t input_frames(void *obj, snd_pcm_uframes_t frames)
+{
+   int num, den;
+   struct rate_src *rate = obj;
+   if (frames == 0)
+      return 0;
+   speex_resampler_get_ratio(rate->st, &num, &den);
+   return (snd_pcm_uframes_t)((frames*num+(den>>1))/den);
+}
+
+static snd_pcm_uframes_t output_frames(void *obj, snd_pcm_uframes_t frames)
+{
+   int num, den;
+   struct rate_src *rate = obj;
+   if (frames == 0)
+      return 0;
+   speex_resampler_get_ratio(rate->st, &num, &den);
+   return (snd_pcm_uframes_t)((frames*den+(num>>1))/num);
+}
+
+static void pcm_src_free(void *obj)
+{
+   struct rate_src *rate = obj;
+   if (rate->st)
+   {
+      speex_resampler_destroy(rate->st);
+      rate->st = NULL;
+   }
+}
+
+static int pcm_src_init(void *obj, snd_pcm_rate_info_t *info)
+{
+   struct rate_src *rate = obj;
+   
+   if (! rate->st || rate->channels != info->channels) {
+      if (rate->st)
+         speex_resampler_destroy(rate->st);
+      rate->channels = info->channels;
+      rate->st = speex_resampler_init_frac(rate->channels, info->in.period_size, info->out.period_size, info->in.rate, info->out.rate, rate->quality);
+      if (! rate->st)
+         return -EINVAL;
+   }
+
+   return 0;
+}
+
+static int pcm_src_adjust_pitch(void *obj, snd_pcm_rate_info_t *info)
+{
+   struct rate_src *rate = obj;
+   speex_resampler_set_rate_frac(rate->st, info->in.period_size, info->out.period_size, info->in.rate, info->out.rate);
+   return 0;
+}
+
+static void pcm_src_reset(void *obj)
+{
+   struct rate_src *rate = obj;
+   speex_resampler_reset_mem(rate->st);
+}
+
+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;
+   speex_resampler_process_interleaved_int(rate->st, src, &src_frames, dst, &dst_frames);
+}
+
+static void pcm_src_close(void *obj)
+{
+   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,
+};
+
+static int pcm_src_open(unsigned int version, void **objp,
+			snd_pcm_rate_ops_t *ops, int quality)
+{
+	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;
+	rate->quality = quality;
+
+	*objp = rate;
+	*ops = pcm_src_ops;
+	return 0;
+}
+
+int SND_PCM_RATE_PLUGIN_ENTRY(speexrate) (unsigned int version, void **objp,
+					   snd_pcm_rate_ops_t *ops)
+{
+	return pcm_src_open(version, objp, ops, 3);
+}
+
+int SND_PCM_RATE_PLUGIN_ENTRY(speexrate_best) (unsigned int version, void **objp,
+						snd_pcm_rate_ops_t *ops)
+{
+	return pcm_src_open(version, objp, ops, 10);
+}
+
+int SND_PCM_RATE_PLUGIN_ENTRY(speexrate_medium) (unsigned int version, void **objp,
+						  snd_pcm_rate_ops_t *ops)
+{
+	return pcm_src_open(version, objp, ops, 5);
+}