generate noisy sine waves instead of pure noise for round-trip samples

diff --git a/src/test_streams/main.c b/src/test_streams/main.c
index d3fe068..b994fc0 100644 (file)
--- a/src/test_streams/main.c
+++ b/src/test_streams/main.c
@@ -51,6 +51,17 @@
 static FLAC__bool is_big_endian_host;
 
 
+static FLAC__bool write_little_endian(FILE *f, FLAC__int32 x, size_t bytes)
+{
+       while(bytes) {
+               if(fputc(x, f) == EOF)
+                       return false;
+               x >>= 8;
+               bytes--;
+       }
+       return true;
+}
+
 static FLAC__bool write_little_endian_uint16(FILE *f, FLAC__uint16 x)
 {
        return
@@ -96,6 +107,19 @@ static FLAC__bool write_little_endian_int32(FILE *f, FLAC__int32 x)
 }
 #endif
 
+static FLAC__bool write_big_endian(FILE *f, FLAC__int32 x, size_t bytes)
+{
+       if(bytes < 4)
+               x <<= 8*(4-bytes);
+       while(bytes) {
+               if(fputc(x>>24, f) == EOF)
+                       return false;
+               x <<= 8;
+               bytes--;
+       }
+       return true;
+}
+
 static FLAC__bool write_big_endian_uint16(FILE *f, FLAC__uint16 x)
 {
        return
@@ -565,13 +589,48 @@ foo:
        return false;
 }
 
+static FLAC__bool generate_raw(const char *filename, unsigned channels, unsigned bytes_per_sample, unsigned samples)
+{
+       const FLAC__int32 full_scale = (1 << (bytes_per_sample*8-1)) - 1;
+       const double f1 = 441.0, a1 = 0.61, f2 = 661.5, a2 = 0.37;
+       const double delta1 = 2.0 * M_PI / ( 44100.0 / f1);
+       const double delta2 = 2.0 * M_PI / ( 44100.0 / f2);
+       double theta1, theta2;
+       FILE *f;
+       unsigned i, j;
+
+       if(0 == (f = fopen(filename, mode)))
+               return false;
+
+       for(i = 0, theta1 = theta2 = 0.0; i < samples; i++, theta1 += delta1, theta2 += delta2) {
+               for(j = 0; j < channels; j++) {
+                       double val = (a1*sin(theta1) + a2*sin(theta2))*(double)full_scale;
+                       FLAC__int32 v = (FLAC__int32)(val + 0.5) + ((GET_RANDOM_BYTE>>4)-8);
+                       if(!write_little_endian(f, v, bytes_per_sample))
+                               goto foo;
+               }
+       }
+
+       fclose(f);
+       return true;
+foo:
+       fclose(f);
+       return false;
+}
+
 static FLAC__bool generate_aiff(const char *filename, unsigned sample_rate, unsigned channels, unsigned bps, unsigned samples)
 {
-       const unsigned true_size = channels * ((bps+7)/8) * samples;
+       const unsigned bytes_per_sample = (bps+7)/8;
+       const unsigned true_size = channels * bytes_per_sample * samples;
        const unsigned padded_size = (true_size + 1) & (~1u);
-       const unsigned shift = 8 - (bps%8);
+       const unsigned shift = (bps%8)? 8 - (bps%8) : 0;
+       const FLAC__int32 full_scale = (1 << (bps-1)) - 1;
+       const double f1 = 441.0, a1 = 0.61, f2 = 661.5, a2 = 0.37;
+       const double delta1 = 2.0 * M_PI / ( sample_rate / f1);
+       const double delta2 = 2.0 * M_PI / ( sample_rate / f2);
+       double theta1, theta2;
        FILE *f;
-       unsigned i;
+       unsigned i, j;
 
        if(0 == (f = fopen(filename, mode)))
                return false;
@@ -596,10 +655,15 @@ static FLAC__bool generate_aiff(const char *filename, unsigned sample_rate, unsi
        if(fwrite("\000\000\000\000\000\000\000\000", 1, 8, f) < 8)
                goto foo;
 
-       for(i = 0; i < true_size; i++)
-               if(fputc(GET_RANDOM_BYTE<<shift, f) == EOF)
-                       goto foo;
-       for( ; i < padded_size; i++)
+       for(i = 0, theta1 = theta2 = 0.0; i < samples; i++, theta1 += delta1, theta2 += delta2) {
+               for(j = 0; j < channels; j++) {
+                       double val = (a1*sin(theta1) + a2*sin(theta2))*(double)full_scale;
+                       FLAC__int32 v = ((FLAC__int32)(val + 0.5) + ((GET_RANDOM_BYTE>>4)-8)) << shift;
+                       if(!write_big_endian(f, v, bytes_per_sample))
+                               goto foo;
+               }
+       }
+       for(i = true_size; i < padded_size; i++)
                if(fputc(0, f) == EOF)
                        goto foo;
 
@@ -617,11 +681,17 @@ static FLAC__bool generate_wav(const char *filename, unsigned sample_rate, unsig
         * (bps%8) allows 24 bps which is technically supposed to be WAVEFORMATEXTENSIBLE but we
         * write 24bps as WAVEFORMATEX since it's unambiguous and matches how flac writes it
         */
-       const unsigned true_size = channels * ((bps+7)/8) * samples;
+       const unsigned bytes_per_sample = (bps+7)/8;
+       const unsigned true_size = channels * bytes_per_sample * samples;
        const unsigned padded_size = (true_size + 1) & (~1u);
        const unsigned shift = (bps%8)? 8 - (bps%8) : 0;
+       const FLAC__int32 full_scale = (1 << (bps-1)) - 1;
+       const double f1 = 441.0, a1 = 0.61, f2 = 661.5, a2 = 0.37;
+       const double delta1 = 2.0 * M_PI / ( sample_rate / f1);
+       const double delta2 = 2.0 * M_PI / ( sample_rate / f2);
+       double theta1, theta2;
        FILE *f;
-       unsigned i;
+       unsigned i, j;
 
        if(0 == (f = fopen(filename, mode)))
                return false;
@@ -639,9 +709,9 @@ static FLAC__bool generate_wav(const char *filename, unsigned sample_rate, unsig
                goto foo;
        if(!write_little_endian_uint32(f, sample_rate))
                goto foo;
-       if(!write_little_endian_uint32(f, sample_rate * channels * ((bps+7)/8)))
+       if(!write_little_endian_uint32(f, sample_rate * channels * bytes_per_sample))
                goto foo;
-       if(!write_little_endian_uint16(f, (FLAC__uint16)(channels * ((bps+7)/8)))) /* block align */
+       if(!write_little_endian_uint16(f, (FLAC__uint16)(channels * bytes_per_sample))) /* block align */
                goto foo;
        if(!write_little_endian_uint16(f, (FLAC__uint16)(bps+shift)))
                goto foo;
@@ -661,10 +731,15 @@ static FLAC__bool generate_wav(const char *filename, unsigned sample_rate, unsig
        if(!write_little_endian_uint32(f, true_size))
                goto foo;
 
-       for(i = 0; i < true_size; i++)
-               if(fputc(GET_RANDOM_BYTE<<shift, f) == EOF)
-                       goto foo;
-       for( ; i < padded_size; i++)
+       for(i = 0, theta1 = theta2 = 0.0; i < samples; i++, theta1 += delta1, theta2 += delta2) {
+               for(j = 0; j < channels; j++) {
+                       double val = (a1*sin(theta1) + a2*sin(theta2))*(double)full_scale;
+                       FLAC__int32 v = ((FLAC__int32)(val + 0.5) + ((GET_RANDOM_BYTE>>4)-8)) << shift;
+                       if(!write_little_endian(f, v, bytes_per_sample))
+                               goto foo;
+               }
+       }
+       for(i = true_size; i < padded_size; i++)
                if(fputc(0, f) == EOF)
                        goto foo;
 
@@ -847,7 +922,7 @@ int main(int argc, char *argv[])
 
                                if(bits_per_sample % 8 == 0) {
                                        sprintf(fn, "rt-%u-%u-%u.raw", channels, bits_per_sample, nsamples[samples]);
-                                       if(!generate_noise(fn, channels * bits_per_sample/8 * nsamples[samples]))
+                                       if(!generate_raw(fn, channels, bits_per_sample/8, nsamples[samples]))
                                                return 1;
                                }
                        }