Use the libspeexdsp resampler

AFAICT it runs a little slower? but it's fixed point, and has much
better understood audio characteristics.

lib/speexdsp/libspeexdsp/testjitter.c

@@ -0,0 +1,75 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "speex/speex_jitter.h"
+#include <stdio.h>
+
+union jbpdata {
+  unsigned int idx;
+  unsigned char data[4];
+};
+
+void synthIn(JitterBufferPacket *in, int idx, int span) {
+  union jbpdata d;
+  d.idx = idx;
+
+  in->data = d.data;
+  in->len = sizeof(d);
+  in->timestamp = idx * 10;
+  in->span = span * 10;
+  in->sequence = idx;
+  in->user_data = 0;
+}
+
+void jitterFill(JitterBuffer *jb) {
+   char buffer[65536];
+   JitterBufferPacket in, out;
+   int i;
+
+   out.data = buffer;
+
+   jitter_buffer_reset(jb);
+
+   for(i=0;i<100;++i) {
+     synthIn(&in, i, 1);
+     jitter_buffer_put(jb, &in);
+
+     out.len = 65536;
+     if (jitter_buffer_get(jb, &out, 10, NULL) != JITTER_BUFFER_OK) {
+       printf("Fill test failed iteration %d\n", i);
+     }
+     if (out.timestamp != i * 10) {
+       printf("Fill test expected %d got %d\n", i*10, out.timestamp);
+     }
+     jitter_buffer_tick(jb);
+   }
+}
+
+int main()
+{
+   char buffer[65536];
+   JitterBufferPacket in, out;
+   int i;
+
+   JitterBuffer *jb = jitter_buffer_init(10);
+
+   out.data = buffer;
+
+   /* Frozen sender case */
+   jitterFill(jb);
+   for(i=0;i<100;++i) {
+     out.len = 65536;
+     jitter_buffer_get(jb, &out, 10, NULL);
+     jitter_buffer_tick(jb);
+   }
+   synthIn(&in, 100, 1);
+   jitter_buffer_put(jb, &in);
+   out.len = 65536;
+   if (jitter_buffer_get(jb, &out, 10, NULL) != JITTER_BUFFER_OK) {
+     printf("Failed frozen sender resynchronize\n");
+   } else {
+     printf("Frozen sender: Jitter %d\n", out.timestamp - 100*10);
+   }
+   return 0;
+}