X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=bitstream.c;h=1593b99ee5bda9fe6f7e47b6ab63c445a10ad529;hp=ddad67bb177211b3909f88d3be9dcb3d5c381238;hb=7afafb8acd2c8ad14802fd2dcfed5567c97454cb;hpb=39ec52d7bfec591dcad0d41bcdbdf6d980bf5913

diff --git a/bitstream.c b/bitstream.c
index ddad67bb..1593b99e 100644
--- a/bitstream.c
+++ b/bitstream.c
@@ -11,14 +11,8 @@
  * For licencing details see COPYING.LIB.
  */
 
-/**
- * \file bitstream.c Bitstream API.
- */
+/** \file bitstream.c Bitstream API for the wma decoder. */
 
-#include <stdlib.h>
-#include <inttypes.h>
-#include <stdio.h>
-#include <string.h>
 #include <regex.h>
 
 #include "para.h"
@@ -27,21 +21,23 @@
 #include "wma.h"
 #include "bitstream.h"
 
-/** Read an 8, 16, or 32 bit entity from a VLC table. */
-#define GET_DATA(v, table, i, size) \
-{\
-	const uint8_t *ptr = (const uint8_t *)table + i * size; \
-	switch (size) { \
-	case 1: \
-		v = *(const uint8_t *)ptr; \
-		break; \
-	case 2: \
-		v = *(const uint16_t *)ptr; \
-		break; \
-	default: \
-		v = *(const uint32_t *)ptr; \
-		break; \
-	} \
+static inline uint32_t get_data(const void *table, int i, int size)
+{
+	const uint8_t *ptr = (const uint8_t *)table + i * size;
+	uint32_t v;
+
+	switch (size) {
+	case 1:
+		v = *(const uint8_t *)ptr;
+		break;
+	case 2:
+		v = *(const uint16_t *)ptr;
+		break;
+	default:
+		v = *(const uint32_t *)ptr;
+		break;
+	}
+	return v;
 }
 
 static void alloc_table(struct vlc *vlc, int size)
@@ -58,8 +54,7 @@ static int build_table(struct vlc *vlc, int table_nb_bits, int nb_codes,
 		const void *bits, const void *codes, int codes_size,
 		uint32_t code_prefix, int n_prefix)
 {
-	int i, j, k, n, table_size, table_index, nb, n1, idx, code_prefix2,
-		symbol;
+	int i, j, k, n, table_size, table_index, nb, n1, idx;
 	uint32_t code;
 	VLC_TYPE(*table)[2];
 
@@ -69,62 +64,57 @@ static int build_table(struct vlc *vlc, int table_nb_bits, int nb_codes,
 	table = &vlc->table[table_index];
 
 	for (i = 0; i < table_size; i++) {
-		table[i][1] = 0;	//bits
-		table[i][0] = -1;	//codes
+		table[i][1] = 0; /* bits */
+		table[i][0] = -1; /* codes */
 	}
 
-	/* map codes and compute auxillary table sizes */
+	/* map codes and compute auxiliary table sizes */
 	for (i = 0; i < nb_codes; i++) {
-		GET_DATA(n, bits, i, 1);
-		GET_DATA(code, codes, i, codes_size);
+		n = get_data(bits, i, 1);
 		/* we accept tables with holes */
+		n -= n_prefix;
 		if (n <= 0)
 			continue;
-		symbol = i;
+		code = get_data(codes, i, codes_size);
 		/* if code matches the prefix, it is in the table */
-		n -= n_prefix;
-		code_prefix2 = code >> n;
-		if (n <= 0 || code_prefix2 != code_prefix)
+		if ((code >> n) != code_prefix)
 			continue;
 		if (n <= table_nb_bits) {
 			/* no need to add another table */
 			j = (code << (table_nb_bits - n)) & (table_size - 1);
 			nb = 1 << (table_nb_bits - n);
 			for (k = 0; k < nb; k++) {
-				if (table[j][1] /* bits */ != 0) {
-					PARA_EMERG_LOG("incorrect code\n");
-					exit(EXIT_FAILURE);
-				}
-				table[j][1] = n;	//bits
-				table[j][0] = symbol;
+				assert(table[j][1] == 0); /* incorrect code */
+				table[j][1] = n; /* bits */
+				table[j][0] = i;
 				j++;
 			}
 		} else {
 			n -= table_nb_bits;
 			j = (code >> n) & ((1 << table_nb_bits) - 1);
 			/* compute table size */
-			n1 = -table[j][1];	//bits
+			n1 = -table[j][1]; /* bits */
 			if (n > n1)
 				n1 = n;
-			table[j][1] = -n1;	//bits
+			table[j][1] = -n1; /* bits */
 		}
 	}
 
-	/* fill auxillary tables recursively */
+	/* fill auxiliary tables recursively */
 	for (i = 0; i < table_size; i++) {
-		n = table[i][1];	//bits
+		n = table[i][1]; /* bits */
 		if (n < 0) {
 			n = -n;
 			if (n > table_nb_bits) {
 				n = table_nb_bits;
-				table[i][1] = -n;	//bits
+				table[i][1] = -n; /* bits */
 			}
 			idx = build_table(vlc, n, nb_codes, bits, codes,
 				codes_size, (code_prefix << table_nb_bits) | i,
 				n_prefix + table_nb_bits);
 			/* vlc->table might have changed */
 			table = &vlc->table[table_index];
-			table[i][0] = idx;	//code
+			table[i][0] = idx; /* code */
 		}
 	}
 	return table_index;
@@ -134,19 +124,15 @@ static int build_table(struct vlc *vlc, int table_nb_bits, int nb_codes,
  * Build VLC decoding tables suitable for use with get_vlc().
  *
  * \param vlc The structure to be initialized.
- *
- * \param nb_bits Set the decoding table size (2^nb_bits) entries. The bigger
- * it is, the faster is the decoding. But it should not be too big to save
- * memory and L1 cache. '9' is a good compromise.
- *
- * \param nb_codes Number of vlcs codes.
- *
+ * \param nb_bits Set the decoding table size (2^nb_bits) entries.
+ * \param nb_codes Number of vlc codes.
  * \param bits Table which gives the size (in bits) of each vlc code.
- *
  * \param codes Table which gives the bit pattern of of each vlc code.
- *
  * \param codes_size The number of bytes of each entry of the \a codes tables.
  *
+ * The bigger \a nb_bits is, the faster is the decoding. But it should not be
+ * too big to save memory and L1 cache. '9' is a good compromise.
+ *
  * The wrap and size parameters allow to use any memory configuration and
  * types (byte/word/long) to store the bits and codes tables.
  */
@@ -178,15 +164,14 @@ void free_vlc(struct vlc *vlc)
  * Parse a vlc code.
  *
  * \param gbc The getbit context structure.
- *
  * \param table The vlc tables to use.
- *
- * \param bits The number of bits which will be read at once, must be
- * identical to nb_bits in init_vlc().
- *
- * \param max_depth The number of times bits bits must be read to completely
+ * \param bits The number of bits which will be read at once.
+ * \param max_depth The number of times \a bits bits must be read to completely
  * read the longest vlc code = (max_vlc_length + bits - 1) / bits.
  *
+ * The \a bits parameter must be identical to the \a nb_bits value supplied to
+ * \ref init_vlc().
+ *
  * \return The vlc code.
  */
 int get_vlc(struct getbit_context *gbc, VLC_TYPE(*table)[2], int bits,