temporary commit

src/libFLAC/bitbuffer.c

@@ -567,6 +567,67 @@ bool FLAC__bitbuffer_write_symmetric_rice_signed_guarded(FLAC__BitBuffer *bb, in
 	return true;
 }
 
+static unsigned silog21_(int v)
+{
+doit_:
+	if(v == 0) {
+		return 0;
+	}
+	else if(v > 0) {
+		unsigned l = 0;
+		while(v) {
+			l++;
+			v >>= 1;
+		}
+		return l+1;
+	}
+	else if(v == -1) {
+		return 2;
+	}
+	else {
+		v = -(++v);
+		goto doit_;
+	}
+}
+
+bool FLAC__bitbuffer_write_symmetric_rice_signed_escape(FLAC__BitBuffer *bb, int val, unsigned parameter)
+{
+	unsigned total_bits, val_bits;
+	uint32 pattern;
+unsigned x;
+
+	assert(bb != 0);
+	assert(bb->buffer != 0);
+	assert(parameter <= 31);
+
+	val_bits = silog21_(val);
+	total_bits = 2 + parameter + 5 + val_bits;
+
+x=bb->total_bits;
+	if(total_bits <= 32) {
+		pattern = 3;
+		pattern <<= (parameter + 5);
+		pattern |= val_bits;
+		pattern <<= val_bits;
+		pattern |= (val & ((1 << val_bits) - 1));
+		if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, total_bits))
+			return false;
+	}
+	else {
+		/* write the '-0' escape code first */
+		if(!FLAC__bitbuffer_write_raw_uint32(bb, 3u << parameter, 2+parameter))
+			return false;
+		/* write the length */
+		if(!FLAC__bitbuffer_write_raw_uint32(bb, val_bits, 5))
+			return false;
+		/* write the value */
+		if(!FLAC__bitbuffer_write_raw_int32(bb, val, val_bits))
+			return false;
+	}
+fprintf(stderr,"wrote %u bits\n",bb->total_bits-x);
+	return true;
+}
+
 bool FLAC__bitbuffer_write_rice_signed(FLAC__BitBuffer *bb, int val, unsigned parameter)
 {
 	unsigned total_bits, interesting_bits, msbs, uval;

src/libFLAC/encoder.c

@@ -1054,19 +1054,45 @@ unsigned encoder_find_best_partition_order_(const int32 residual[], uint32 abs_r
 	return best_residual_bits;
 }
 
-static unsigned iilog2_(unsigned v)
+static unsigned silog21_(int v)
+{
+doit_:
+	if(v == 0) {
+		return 0;
+	}
+	else if(v > 0) {
+		unsigned l = 0;
+		while(v) {
+			l++;
+			v >>= 1;
+		}
+		return l+1;
+	}
+	else if(v == -1) {
+		return 2;
+	}
+	else {
+		v = -(++v);
+		goto doit_;
+	}
+}
+
+static unsigned uilog21_(unsigned v)
 {
 	unsigned l = 0;
-	assert(v > 0);
-	while(v >>= 1)
+	while(v) {
 		l++;
+		v >>= 1;
+	}
 	return l;
 }
 
+const double smult = 3.0;
+const unsigned rpdec = 0;
+
 static uint32 get_thresh_(const int32 residual[], const unsigned residual_samples)
 {
 	double sum, sos, r, stddev, mean;
-	const double smult = 2.0;
 	unsigned i;
 	uint32 thresh;
 
@@ -1079,7 +1105,7 @@ static uint32 get_thresh_(const int32 residual[], const unsigned residual_sample
 	mean = sum / residual_samples;
 	stddev = sqrt((sos - (sum * sum / residual_samples)) / (residual_samples-1));
 	thresh = mean+smult*stddev;
-	thresh = iilog2_(thresh);
+	thresh = (1u << uilog21_(thresh)) - 1;
 	return thresh;
 }
 
@@ -1094,11 +1120,10 @@ bool encoder_set_partitioned_rice_(const int32 residual[], const uint32 abs_resi
 
 	if(partition_order == 0) {
 		unsigned i;
+#ifdef SYMMETRIC_RICE
 		uint32 thresh = get_thresh_(residual, residual_samples);
-		const unsigned rpdec = 1;
 		bool cross = false;
 
-#ifdef SYMMETRIC_RICE
 		for(i=0;i<residual_samples;i++) {
 			if(abs_residual[i] >= thresh) {
 				cross = true;
@@ -1124,10 +1149,16 @@ bool encoder_set_partitioned_rice_(const int32 residual[], const uint32 abs_resi
 			for(i = 0; i < residual_samples; i++) {
 #ifdef VARIABLE_RICE_BITS
 #ifdef SYMMETRIC_RICE
-				if(cross && abs_residual[i] >= thresh)
-					bits_ += VARIABLE_RICE_BITS(0, rice_parameter) + 5 + iilog2_(abs_residual) + 1;
-				else
+				if(cross) {
+					unsigned escbits, normbits;
+					escbits = /* VARIABLE_RICE_BITS(0, rice_parameter) == 0 */ 5 + silog21_(residual[i]);
+					normbits = VARIABLE_RICE_BITS(abs_residual[i], rice_parameter);
+					bits += min(escbits, normbits);
+				}
+				else {
+					/*@@@ old way */
 					bits_ += VARIABLE_RICE_BITS(abs_residual[i], rice_parameter);
+				}
 #else
 				bits_ += VARIABLE_RICE_BITS(abs_residual[i], rice_parameter_estimate);
 #endif

src/libFLAC/encoder_framing.c

@@ -19,6 +19,7 @@
 
 #include <assert.h>
 #include <stdio.h>
+#include <math.h>
 #include "private/encoder_framing.h"
 #include "private/crc.h"
 
@@ -319,16 +320,100 @@ bool subframe_add_entropy_coding_method_(FLAC__BitBuffer *bb, const FLAC__Entrop
 	return true;
 }
 
+static unsigned silog21_(int v)
+{
+doit_:
+	if(v == 0) {
+		return 0;
+	}
+	else if(v > 0) {
+		unsigned l = 0;
+		while(v) {
+			l++;
+			v >>= 1;
+		}
+		return l+1;
+	}
+	else if(v == -1) {
+		return 2;
+	}
+	else {
+		v = -(++v);
+		goto doit_;
+	}
+}
+
+static unsigned uilog21_(unsigned v)
+{
+	unsigned l = 0;
+	while(v) {
+		l++;
+		v >>= 1;
+	}
+	return l;
+}
+
+extern const double smult;
+
+static uint32 get_thresh_(const int32 residual[], const unsigned residual_samples)
+{
+	double sum, sos, r, stddev, mean;
+	unsigned i;
+	uint32 thresh;
+
+	sum = sos = 0.0;
+	for(i = 0; i < residual_samples; i++) {
+		r = (double)residual[i];
+		sum += r;
+		sos += r*r;
+	}
+	mean = sum / residual_samples;
+	stddev = sqrt((sos - (sum * sum / residual_samples)) / (residual_samples-1));
+	thresh = mean+smult*stddev;
+	thresh = (1u << uilog21_(thresh)) - 1;
+	return thresh;
+}
+
 bool subframe_add_residual_partitioned_rice_(FLAC__BitBuffer *bb, const int32 residual[], const unsigned residual_samples, const unsigned predictor_order, const unsigned rice_parameters[], const unsigned partition_order)
 {
 	if(partition_order == 0) {
 		unsigned i;
+#ifdef SYMMETRIC_RICE
+		uint32 thresh = get_thresh_(residual, residual_samples);
+		bool cross = false;
+
+		for(i=0;i<residual_samples;i++) {
+			uint32 a = (residual[i] < 0? -residual[i] : residual[i]);
+			if(a >= thresh) {
+				cross = true;
+				break;
+			}
+		}
+#endif
+
 		if(!FLAC__bitbuffer_write_raw_uint32(bb, rice_parameters[0], FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN))
 			return false;
 		for(i = 0; i < residual_samples; i++) {
 #ifdef SYMMETRIC_RICE
-			if(!FLAC__bitbuffer_write_symmetric_rice_signed(bb, residual[i], rice_parameters[0]))
-				return false;
+			if(cross) {
+				unsigned escbits, normbits;
+				uint32 a = (residual[i] < 0? -residual[i] : residual[i]);
+				escbits = 5 + silog21_(residual[i]);
+				normbits = a >> rice_parameters[0];
+				if(escbits < normbits) {
+fprintf(stderr,"ESCAPE, k=%u, r=%d, saved %u bits\n", rice_parameters[0], residual[i], normbits-escbits);
+					if(!FLAC__bitbuffer_write_symmetric_rice_signed_escape(bb, residual[i], rice_parameters[0]))
+						return false;
+				}
+				else {
+					if(!FLAC__bitbuffer_write_symmetric_rice_signed(bb, residual[i], rice_parameters[0]))
+						return false;
+				}
+			}
+			else {
+				if(!FLAC__bitbuffer_write_symmetric_rice_signed(bb, residual[i], rice_parameters[0]))
+					return false;
+			}
 #else
 			if(!FLAC__bitbuffer_write_rice_signed(bb, residual[i], rice_parameters[0]))
 				return false;