X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=wma_common.c;h=ee7f451eebbadd65bac712baf1cc042879452281;hp=5ea92c73948f70a66ff80aa830adba857f582a4f;hb=4744d937c4160898d1fe151257606430750e580c;hpb=03900fe178fa1dc6b371424c8a96f91be52877e2;ds=inline

diff --git a/wma_common.c b/wma_common.c
index 5ea92c73..ee7f451e 100644
--- a/wma_common.c
+++ b/wma_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2009-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -21,17 +21,27 @@
 #include "imdct.h"
 #include "wma.h"
 
-const char *search_pattern(const char *pattern, int pattern_len, const char *buf, int buf_size)
+/**
+ * Find the first occurrence of the given pattern.
+ *
+ * \param pattern The pattern to search for.
+ * \param pattern_len The length of the pattern in bytes.
+ * \param buf The buffer to search for the pattern.
+ * \param buf_size The number of bytes in \a buf.
+ *
+ * \return A pointer into \a buf or \p NULL if the pattern was not found.
+ */
+const char *search_pattern(const char *pattern, int pattern_len,
+		const char *buf, int buf_size)
 {
 	const char *p, *end = buf + buf_size;
 
-	if (pattern_len > buf_size)
-		return NULL;
+	/* TODO: Use suffix arrays to speed up the search. */
 	for (p = buf; p + pattern_len < end; p++) {
 		if (memcmp(p, pattern, pattern_len))
 			continue;
 		PARA_DEBUG_LOG("found %d byte pattern@%d\n",
-			pattern_len, p - buf);
+			pattern_len, (int)(p - buf));
 		return p;
 	}
 	PARA_NOTICE_LOG("%d byte pattern not found\n", pattern_len);
@@ -48,11 +58,11 @@ static int find_audio_stream_info(const char *buf, int len)
 
 	if (!p)
 		return -E_WMA_NO_GUID;
-	PARA_DEBUG_LOG("found audio stream guid@%0zx\n", p - buf);
-	return p - buf;
+	PARA_DEBUG_LOG("found audio stream guid@%0x\n", (int)(p - buf));
+	return p - buf + 16;
 }
 
-static int read_header_len(char *buf, int len)
+static int read_header_len(const char *buf, int len)
 {
 	uint16_t header_len;
 
@@ -64,13 +74,19 @@ static int read_header_len(char *buf, int len)
 }
 
 /**
+ * Read an asf audio file header.
+ *
+ * \param buf The input buffer.
+ * \param loaded Number of bytes in \a buf.
+ * \param ahi Result pointer.
+ *
  * \return Negative on errors, zero if more data is needed in order to read the
- * full header. Positive header length on success.
+ * full header, 1 on success.
  */
-int read_asf_header(char *buf, int loaded, struct asf_header_info *ahi)
+int read_asf_header(const char *buf, int loaded, struct asf_header_info *ahi)
 {
 	int ret;
-	char *start;
+	const char *start;
 
 	ahi->header_len = read_header_len(buf, loaded);
 	if (ahi->header_len == 0) /* too short to read header len */
@@ -80,9 +96,10 @@ int read_asf_header(char *buf, int loaded, struct asf_header_info *ahi)
 	ret = find_audio_stream_info(buf, ahi->header_len);
 	if (ret < 0)
 		return ret;
-	ahi->audio_stream_info_start = ret + 16;
+	if (ret + 62 > loaded)
+		return 0;
+	ahi->audio_stream_info_start = ret;
 	start = buf + ahi->audio_stream_info_start;
-
 	ahi->channels = ((uint8_t *)start)[40];
 	ahi->sample_rate = read_u16(start + 42);
 	PARA_NOTICE_LOG("%d channels, sample rate: %d\n", ahi->channels,
@@ -101,7 +118,7 @@ int read_asf_header(char *buf, int loaded, struct asf_header_info *ahi)
 	return 1;
 }
 
-const uint8_t log2_tab[256] = {
+static const uint8_t log2_tab[256] = {
 	0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
 	4, 4, 4, 4, 4, 4, 4, 4,
 	5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
@@ -120,7 +137,14 @@ const uint8_t log2_tab[256] = {
 	7, 7, 7, 7, 7, 7, 7, 7
 };
 
-int wma_log2(unsigned int v)
+/**
+ * Compute the base-2 logarithm.
+ *
+ * \param v The value to compute the logarithm of.
+ *
+ * \return An integer approximation of log2(v).
+ */
+__a_const int wma_log2(unsigned int v)
 {
 	int n = 0;
 	if (v & 0xffff0000) {