From: drowe67 <drowe67@01035d8c-6547-0410-b346-abe4f91aad63>
Date: Mon, 30 Jan 2017 05:27:39 +0000 (+0000)
Subject: added 8 bit signed ouput example, scatter looks OK
X-Git-Url: http://git.whiteaudio.com/gitweb/?a=commitdiff_plain;h=79bb10637ea3ca56133ab0b5b195d75a94466fa1;p=freetel-svn-tracking.git

added 8 bit signed ouput example, scatter looks OK

git-svn-id: https://svn.code.sf.net/p/freetel/code@3007 01035d8c-6547-0410-b346-abe4f91aad63
---

diff --git a/codec2-dev/unittest/tdec.c b/codec2-dev/unittest/tdec.c
index 724dfa49..6b1f245f 100644
--- a/codec2-dev/unittest/tdec.c
+++ b/codec2-dev/unittest/tdec.c
@@ -1,11 +1,9 @@
 /*
-   tlininterp.c
+   tdec.c
    David Rowe
    Jan 2017
 
-   Linear interpolator, CPU effecient way of getting large oversample
-   ratios, if the input is already limited to a fraction of the
-   input sampling rate.
+   Trivial non filtered decimator for high ration sample rate conversion.
 
    build: gcc tdec.c -o tdec -Wall -O2
 
@@ -16,11 +14,16 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
+
+#define SIGNED_16BIT   0
+#define SIGNED_8BIT    1
 
 void display_help(void) {
     fprintf(stderr, "\nusage: tdec inputRawFile OutputRawFile DecimationRatio [-c]\n");
     fprintf(stderr, "\nUse - for stdin/stdout\n\n");
-    fprintf(stderr, "-c complex (two channel) resampling\n\n");
+    fprintf(stderr, "-c complex signed 16 bit input and output\n");
+    fprintf(stderr, "-d complex signed 8 bit input, complex signed 16 bit output\n\n");
 }
 
 int main(int argc, char *argv[]) {
@@ -48,19 +51,37 @@ int main(int argc, char *argv[]) {
 
     int channels = 1;
     int opt;
-    while ((opt = getopt(argc, argv, "c")) != -1) {
+    int format = SIGNED_16BIT;
+    while ((opt = getopt(argc, argv, "cd")) != -1) {
         switch (opt) {
         case 'c': channels = 2; break;
+        case 'd': channels = 2; format = SIGNED_8BIT; break;
         default:
             display_help();
             exit(1);
         }
     }
 
-    short buf[dec*channels];
-    fprintf(stderr, "dec: %d\n", dec);
-    while(fread(buf, sizeof(short)*channels, dec, fin) == dec) {
-        fwrite(buf, sizeof(short), channels, fout);
+    if (format == SIGNED_16BIT) {
+        short buf[dec*channels];
+        while(fread(buf, sizeof(short)*channels, dec, fin) == dec) {
+            fwrite(buf, sizeof(short), channels, fout);
+        }
+    }
+    else {
+        uint8_t inbuf[dec*channels];
+        short   outbuf[channels];
+        short   sam, i;
+        
+        while(fread(inbuf, sizeof(uint8_t)*channels, dec, fin) == dec) {
+            for (i=0; i<channels; i++) {
+                sam = (short)inbuf[i];
+                sam <<= 8;
+                outbuf[i] = sam;
+            }
+            fwrite(outbuf, sizeof(short), channels, fout);
+        }
+
     }
 
     fclose(fout);
diff --git a/codec2-dev/unittest/tlininterp.c b/codec2-dev/unittest/tlininterp.c
index 1c5b2905..8ec89b46 100644
--- a/codec2-dev/unittest/tlininterp.c
+++ b/codec2-dev/unittest/tlininterp.c
@@ -3,9 +3,9 @@
    David Rowe
    Jan 2017
 
-   Linear interpolator, CPU effecient way of getting large oversample
-   ratios, if the input is already limited to a fraction of the
-   input sampling rate.
+   Fast linear interpolator for high oversam[pling rates.  Upsample
+   with a decent filter first such that the signal is "low pass" wrt
+   to the input sample rate.
 
    build: gcc tlininterp.c -o tlininterp -Wall -O2
 
@@ -16,19 +16,23 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdint.h>
 
-#define N    10000                   /* processing buffer size */
+#define SIGNED_16BIT   0
+#define SIGNED_8BIT    1
 
 void display_help(void) {
     fprintf(stderr, "\nusage: tlininterp inputRawFile OutputRawFile OverSampleRatio [-c]\n");
     fprintf(stderr, "\nUse - for stdin/stdout\n\n");
-    fprintf(stderr, "-c complex (two channel) resampling\n\n");
+    fprintf(stderr, "-c complex signed 16 bit input and output\n");
+    fprintf(stderr, "-d complex signed 16 bit input, complex signed 8 bit output\n\n");
 }
 
 int main(int argc, char *argv[]) {
     FILE       *fin, *fout;
-    short       left, right, out;
+    short       left[2], right[2], out[2], i;
     float       oversample, t;
+    int8_t      out_s8[2];
 
     if (argc < 3) {
 	display_help();
@@ -50,26 +54,43 @@ int main(int argc, char *argv[]) {
     oversample = atof(argv[3]);
 
     int channels = 1;
+    int format = SIGNED_16BIT;
     int opt;
-    while ((opt = getopt(argc, argv, "c")) != -1) {
+    while ((opt = getopt(argc, argv, "cd")) != -1) {
         switch (opt) {
         case 'c': channels = 2; break;
+        case 'd': channels = 2; format = SIGNED_8BIT; break;
         default:
             display_help();
             exit(1);
         }
     }
 
-    left = 0;
+    for (i=0; i<channels; i++)
+        left[i] = 0;
     t = 0.0;
-    while(fread(&right, sizeof(short), 1, fin) == 1) {
+    while(fread(&right, sizeof(short)*channels, 1, fin) == 1) {
         while (t < 1.0) {
-            out = (1.0 - t)*left + t*right;
-            fwrite(&out, sizeof(short), 1, fout);
+
+            for (i=0; i<channels; i++) {
+                out[i] = (1.0 - t)*left[i] + t*right[i];
+            }
+
+            if (format == SIGNED_16BIT) {
+                fwrite(&out, sizeof(short), channels, fout);
+            } else {
+                //fprintf(stderr,"8 bit out\n");
+                for (i=0; i<channels; i++) {
+                    out_s8[i] = out[i] >> 8;
+                }
+                fwrite(&out_s8, sizeof(int8_t), channels, fout);
+            }
+
             t += 1.0/oversample;
         }
         t -= 1.0;
-        left = right;
+        for (i=0; i<channels; i++)
+            left[i] = right[i];
     }
 
     fclose(fout);