pcm_resample: don't resample partial samples

Added assertions which ensure that there are no partial samples in the
source buffer.

src/pcm_resample_fallback.c

@@ -20,6 +20,8 @@
 #include "pcm_resample.h"
 #include "gcc.h"
 
+#include <assert.h>
+
 /* resampling code blatantly ripped from ESD */
 size_t
 pcm_resample_16(uint8_t channels,
@@ -33,6 +35,9 @@ pcm_resample_16(uint8_t channels,
 	unsigned dest_samples = dest_size / sizeof(*dest_buffer);
 	int16_t lsample, rsample;
 
+	assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
+	assert((dest_size % (sizeof(*dest_buffer) * channels)) == 0);
+
 	switch (channels) {
 	case 1:
 		while (dest_pos < dest_samples) {

src/pcm_resample_libsamplerate.c

@@ -22,6 +22,7 @@
 #include "log.h"
 #include "utils.h"
 
+#include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -75,6 +76,9 @@ pcm_resample_16(uint8_t channels,
 	size_t data_out_size;
 	int error;
 
+	assert((src_size % (sizeof(*src_buffer) * channels)) == 0);
+	assert((dest_size % (sizeof(*dest_buffer) * channels)) == 0);
+
 	if (convalgo < 0)
 		convalgo = pcm_resample_get_converter();