2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file wma_common.c Functions used by both the WMA afh and decoder. */
10 #include <sys/types.h>
20 #include "portable_io.h"
24 const char *search_pattern(const char *pattern, int pattern_len, const char *buf, int buf_size)
26 const char *p, *end = buf + buf_size;
28 for (p = buf; p + pattern_len < end; p++) {
29 if (memcmp(p, pattern, pattern_len))
31 PARA_DEBUG_LOG("found %d byte pattern@%d\n",
32 pattern_len, p - buf);
35 PARA_NOTICE_LOG("%d byte pattern not found\n", pattern_len);
40 40 9e 69 f8 4d 5b cf 11 a8 fd 00 80 5f 5c 44 2b
42 static int find_audio_stream_info(const char *buf, int len)
44 const char pattern[] = {0x40, 0x9e, 0x69, 0xf8};
45 const char *p = search_pattern(pattern, sizeof(pattern), buf, len);
48 return -E_WMA_NO_GUID;
49 PARA_DEBUG_LOG("found audio stream guid@%0zx\n", p - buf);
53 static int read_header_len(char *buf, int len)
59 header_len = read_u16(buf + 16) + 46;
60 PARA_DEBUG_LOG("header_len: %d\n", header_len);
65 * Read an asf audio file header.
67 * \param buf The input buffer.
68 * \param loaded Number of bytes in \a buf.
69 * \param ahi Result pointer.
71 * \return Negative on errors, zero if more data is needed in order to read the
72 * full header, 1 on success.
74 int read_asf_header(char *buf, int loaded, struct asf_header_info *ahi)
79 ahi->header_len = read_header_len(buf, loaded);
80 if (ahi->header_len == 0) /* too short to read header len */
82 if (ahi->header_len > loaded) /* too short to read header */
84 ret = find_audio_stream_info(buf, ahi->header_len);
87 if (ret + 62 > loaded)
89 ahi->audio_stream_info_start = ret;
90 start = buf + ahi->audio_stream_info_start;
91 ahi->channels = ((uint8_t *)start)[40];
92 ahi->sample_rate = read_u16(start + 42);
93 PARA_NOTICE_LOG("%d channels, sample rate: %d\n", ahi->channels,
96 ahi->bit_rate = 8 * read_u16(start + 46);
97 PARA_INFO_LOG("bit rate: %d\n", ahi->bit_rate);
99 ahi->block_align = read_u16(start + 50);
100 PARA_INFO_LOG("block_align: %d\n", ahi->block_align);
102 ahi->flags1 = read_u32(start + 56);
103 ahi->flags2 = read_u16(start + 60);
104 PARA_INFO_LOG("read_asf_header: flags1: %d, flag2: %d\n",
105 ahi->flags1, ahi->flags2);
109 const uint8_t log2_tab[256] = {
110 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
111 4, 4, 4, 4, 4, 4, 4, 4,
112 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
113 5, 5, 5, 5, 5, 5, 5, 5,
114 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
115 6, 6, 6, 6, 6, 6, 6, 6,
116 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
117 6, 6, 6, 6, 6, 6, 6, 6,
118 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
119 7, 7, 7, 7, 7, 7, 7, 7,
120 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
121 7, 7, 7, 7, 7, 7, 7, 7,
122 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
123 7, 7, 7, 7, 7, 7, 7, 7,
124 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
125 7, 7, 7, 7, 7, 7, 7, 7
128 int wma_log2(unsigned int v)
131 if (v & 0xffff0000) {