getting ready for auto resample in opposing versions of SLIN codec

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@232 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch_utils.h

@@ -70,6 +70,10 @@ SWITCH_DECLARE(switch_status) switch_socket_create_pollfd(switch_pollfd_t *poll,
 SWITCH_DECLARE(int) switch_socket_waitfor(switch_pollfd_t *poll, int ms);
 SWITCH_DECLARE(void) switch_swap_linear(int16_t *buf, int len);
 SWITCH_DECLARE(char *) switch_cut_path(char *in);
+SWITCH_DECLARE(int) float_to_short(float *f, short *s, int len);
+SWITCH_DECLARE(int) char_to_float(char *c, float *f, int len);
+SWITCH_DECLARE(int) float_to_char(float *f, char *c, int len);
+SWITCH_DECLARE(int) short_to_float(short *s, float *f, int len);
 
 #if !defined(switch_strdupa) && defined(__GNUC__)
 # define switch_strdupa(s)									\

src/mod/mod_rawaudio/mod_rawaudio.c

@@ -34,16 +34,60 @@
 
 static const char modname[] = "mod_rawaudio";
 
+#ifndef MIN
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+#endif
+
+#ifndef MAX
+#define MAX(a,b) ((a) > (b) ? (a) : (b))
+#endif
+
+struct raw_context {
+	void *enc_resampler;
+	int enc_from;
+	int enc_to;
+	double enc_factor;
+	void *dec_resampler;
+	int dec_from;
+	int dec_to;
+	double dec_factor;
+};
+
+
+static int resample(void *handle, double factor, float *src, int srclen, float *dst, int dstlen, int last)
+{
+    int o=0, srcused=0, srcpos=0, out=0;
+
+    for(;;) {
+        int srcBlock = MIN(srclen-srcpos, srclen);
+        int lastFlag = (last && (srcBlock == srclen-srcpos));
+        printf("resampling %d/%d (%d)\n",  srcpos, srclen,  MIN(dstlen-out, dstlen));
+        o = resample_process(handle, factor, &src[srcpos], srcBlock, lastFlag, &srcused, &dst[out], dstlen-out);
+        srcpos += srcused;
+        if (o >= 0)
+            out += o;
+        if (o < 0 || (o == 0 && srcpos == srclen))
+            break;
+    }
+    return out;
+}
+
+
 static switch_status switch_raw_init(switch_codec *codec, switch_codec_flag flags, const struct switch_codec_settings *codec_settings)
 {
 	int encoding, decoding;
-	
+	struct raw_context *context = NULL;
+
 	encoding = (flags & SWITCH_CODEC_FLAG_ENCODE);
 	decoding = (flags & SWITCH_CODEC_FLAG_DECODE);
 
 	if (!(encoding || decoding)) {
 		return SWITCH_STATUS_FALSE;
 	} else {
+		if (!(context = switch_core_alloc(codec->memory_pool, sizeof(*context)))) {
+			return SWITCH_STATUS_MEMERR;
+		}
+		codec->private = context;
 		return SWITCH_STATUS_SUCCESS;
 	}
 }
@@ -56,12 +100,28 @@ static switch_status switch_raw_encode(switch_codec *codec,
 								 size_t *encoded_data_len,
 								 unsigned int *flag)
 {
+	struct raw_context *context = codec->private;
+
 	/* NOOP indicates that the audio in is already the same as the audio out, so no conversion was necessary.
-	   TBD look at other_codec to determine the original format of the data and determine if we need to resample
-	   in the event the audio is the same format but different implementations.
+	   TBD Support varying number of channels
 	*/
-	printf("encode %d %d->%d\n", decoded_data_len, other_codec->implementation->bytes_per_frame, codec->implementation->bytes_per_frame);
 
+	if (codec->implementation->samples_per_second != other_codec->implementation->samples_per_second) {
+		if (!context->enc_from) {
+			printf("Activate Resample %d->%d\n", codec->implementation->samples_per_second, other_codec->implementation->samples_per_second);
+			context->enc_from = codec->implementation->samples_per_second;
+			context->enc_to = other_codec->implementation->samples_per_second;
+			context->enc_factor = ((double)other_codec->implementation->samples_per_second / (double)codec->implementation->samples_per_second);
+			context->enc_resampler = resample_open(1, context->enc_factor, context->enc_factor);
+		}
+
+		if (context->enc_from) {
+	
+		}
+
+		return SWITCH_STATUS_SUCCESS;
+	}
+	
 	return SWITCH_STATUS_NOOP;
 }
 
@@ -73,6 +133,7 @@ static switch_status switch_raw_decode(switch_codec *codec,
 								 size_t *decoded_data_len,
 								 unsigned int *flag) 
 {
+	struct raw_context *context = codec->private;
 
 	printf("decode %d %d->%d\n", encoded_data_len, other_codec->implementation->bytes_per_frame, codec->implementation->bytes_per_frame);
 

src/switch_utils.c

@@ -30,6 +30,74 @@
  *
  */
 #include <switch_utils.h>
+#define NORMFACT (float)0x8000
+#define MAXSAMPLE (float)0x7FFF
+#define MAXSAMPLEC (char)0x7F
+
+
+SWITCH_DECLARE(int) float_to_short(float *f, short *s, int len)
+{
+    int i;
+    float ft;
+        for(i=0;i<len;i++) {
+                ft = f[i] * NORMFACT;
+        if(ft >= 0) {
+            s[i] = (short)(ft+0.5);
+        } else {
+            s[i] = (short)(ft-0.5);
+        }
+        if (s[i] > (short)MAXSAMPLE) s[i] = (short)MAXSAMPLE;
+        if (s[i] < (short)-MAXSAMPLE) s[i] = (short)-MAXSAMPLE;
+        }
+    return len;
+}
+
+SWITCH_DECLARE(int) char_to_float(char *c, float *f, int len)
+{
+    int i;
+
+    if (len % 2) {
+        return(-1);
+    }
+
+        for(i=1;i<len;i+=2) {
+        f[(int)(i/2)] = (float)(((c[i])*0x100) + c[i-1]);
+        f[(int)(i/2)] /= NORMFACT;
+        if (f[(int)(i/2)] > MAXSAMPLE) f[(int)(i/2)] = MAXSAMPLE;
+        if (f[(int)(i/2)] < -MAXSAMPLE) f[(int)(i/2)] = -MAXSAMPLE;
+        }
+    return len/2;
+}
+
+SWITCH_DECLARE(int) float_to_char(float *f, char *c, int len)
+{
+    int i;
+    float ft;
+    long l;
+        for(i=0;i<len;i++) {
+        ft = f[i] * NORMFACT;
+        if (ft >= 0) {
+            l = (long)(ft+0.5);
+        } else {
+            l = (long)(ft-0.5);
+        }
+        c[i*2] = (unsigned char)((l)&0xff);
+        c[i*2+1] = (unsigned char)(((l)>>8)&0xff);
+        }
+    return len*2;
+}
+
+SWITCH_DECLARE(int) short_to_float(short *s, float *f, int len)
+{
+    int i;
+    int min, max;
+    min = max = 0;
+
+        for(i=0;i<len;i++) {
+                f[i] = (float)(s[i]) / NORMFACT;
+        }
+    return len;
+}
 
 SWITCH_DECLARE(char *) switch_cut_path(char *in)
 {