Use the libspeexdsp resampler

AFAICT it runs a little slower? but it's fixed point, and has much better understood audio characteristics.
2023-08-10 19:12:38 +10:00
parent d8fc77101d
commit 958160aa54
163 changed files with 77244 additions and 253 deletions
@@ -0,0 +1,93 @@
+/* Copyright (C) 2007 Jean-Marc Valin
+
+   File: testresample2.c
+   Testing the resampling code
+
+   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.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "speex/speex_resampler.h"
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+#define PERIOD 32
+#define INBLOCK 1024
+#define RATE 48000
+
+int main()
+{
+   spx_uint32_t i;
+   float *fin, *fout;
+   int rate = 1000, off = 0, avail = INBLOCK;
+   SpeexResamplerState *st = speex_resampler_init(1, RATE, RATE, 4, NULL);
+   speex_resampler_set_rate(st, RATE, rate);
+   speex_resampler_skip_zeros(st);
+
+   fin = malloc(INBLOCK*2*sizeof(float));
+   for (i=0; i<INBLOCK*2;i++)
+     fin[i] = sinf ((float)i/PERIOD * 2 * M_PI) * 0.9;
+
+   fout = malloc(INBLOCK*4*sizeof(float));
+
+   while (1)
+   {
+      spx_uint32_t in_len;
+      spx_uint32_t out_len;
+
+      in_len = avail;
+      out_len = (in_len * rate + RATE-1) / RATE;
+
+      fprintf (stderr, "%d %d %d %d -> ", rate, off, in_len, out_len);
+
+      speex_resampler_process_float(st, 0, fin + off, &in_len, fout, &out_len);
+
+      fprintf (stderr, "%d %d\n", in_len, out_len);
+      off += in_len;
+      avail = avail - in_len + INBLOCK;
+
+      if (off >= INBLOCK)
+        off -= INBLOCK;
+
+      fwrite(fout, sizeof(float), out_len, stdout);
+
+      rate += 100;
+      if (rate > 128000)
+        break;
+
+      speex_resampler_set_rate(st, RATE, rate);
+   }
+   speex_resampler_destroy(st);
+   free(fin);
+   free(fout);
+   return 0;
+}
+