wma_afh.c

   1 /*
   2  * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file wma_afh.c The audio format handler for WMA files. */
   8
   9 #include <stdlib.h>
  10 #include <inttypes.h>
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <fcntl.h>
  14 #include <stdio.h>
  15 #include <unistd.h>
  16 #include <string.h>
  17 #include <regex.h>
  18
  19 #include "para.h"
  20 #include "error.h"
  21 #include "afh.h"
  22 #include "portable_io.h"
  23 #include "string.h"
  24 #include "wma.h"
  25
  26 #define FOR_EACH_FRAME(_f, _buf, _size, _ba) for (_f = (_buf); \
  27         _f + (_ba) + WMA_FRAME_SKIP < (_buf) + (_size); \
  28         _f += (_ba) + WMA_FRAME_SKIP)
  29
  30 static int count_frames(const char *buf, int buf_size, int block_align,
  31         long unsigned *num_superframes)
  32 {
  33         int count = 0, step = block_align + WMA_FRAME_SKIP;
  34         const uint8_t *p = (uint8_t *)buf + WMA_FRAME_SKIP;
  35
  36
  37         if (buf_size <= WMA_FRAME_SKIP) {
  38                 if (num_superframes)
  39                         *num_superframes = 0;
  40                 return 0;
  41         }
  42         count = 0;
  43         step = block_align + WMA_FRAME_SKIP;
  44         p = (uint8_t *)buf + WMA_FRAME_SKIP;
  45
  46         FOR_EACH_FRAME(p, (uint8_t *)buf, buf_size, block_align)
  47                 count += p[WMA_FRAME_SKIP] & 0x0f;
  48         PARA_DEBUG_LOG("%d frames\n", count);
  49         if (num_superframes) {
  50                 *num_superframes = buf_size / step;
  51                 PARA_DEBUG_LOG("%lu superframes\n", *num_superframes);
  52         }
  53         return count;
  54 }
  55
  56 /*
  57  * put_utf8() and get_str16() below are based on macros in libavutil/common.h
  58  * of the mplayer source code, copyright (c) 2006 Michael Niedermayer
  59  * <michaelni@gmx.at>.
  60  */
  61
  62 /*
  63  * Convert a 32-bit Unicode character to its UTF-8 encoded form.
  64  *
  65  * Writes up to 4 bytes for values in the valid UTF-8 range and up to 7 bytes
  66  * in the general case, depending on the length of the converted Unicode
  67  * character.
  68  *
  69  * \param result Where the converted UTF-8 bytes are written.
  70  */
  71 static int put_utf8(uint32_t val, char *result)
  72 {
  73         char *out = result;
  74         int bytes, shift;
  75         uint32_t in = val;
  76
  77         if (in < 0x80) {
  78                 *out++ = in;
  79                 return 1;
  80         }
  81         bytes = (wma_log2(in) + 4) / 5;
  82         shift = (bytes - 1) * 6;
  83         *out++ = (256 - (256 >> bytes)) | (in >> shift);
  84         while (shift >= 6) {
  85                 shift -= 6;
  86                 *out++ = 0x80 | ((in >> shift) & 0x3f);
  87         }
  88         return out - result;
  89 }
  90
  91 static void get_str16(const char *in, int len, char *out, int out_size)
  92 {
  93         const char *p = in;
  94         char *q = out;
  95
  96         len /= 2;
  97         while (len-- && q + 7 + 1 < out + out_size) {
  98                 uint32_t x = read_u16(p);
  99                 p += 2;
 100                 q += put_utf8(x, q);
 101                 if (x == 0)
 102                         return;
 103         }
 104         *q = '\0';
 105 }
 106
 107 static const char comment_header[] = {
 108         0x33, 0x26, 0xb2, 0x75, 0x8E, 0x66, 0xCF, 0x11,
 109         0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 0xce, 0x6c
 110 };
 111
 112 static const char extended_content_header[] = {
 113         0x40, 0xA4, 0xD0, 0xD2, 0x07, 0xE3, 0xD2, 0x11,
 114         0x97, 0xF0, 0x00, 0xA0, 0xC9, 0x5E, 0xA8, 0x50
 115 };
 116
 117 static const char year_tag_header[] = { /* WM/Year */
 118         0x57, 0x00, 0x4d, 0x00, 0x2f, 0x00, 0x59, 0x00,
 119         0x65, 0x00, 0x61, 0x00, 0x72, 0x00
 120 };
 121
 122 static const char album_tag_header[] = { /* WM/AlbumTitle */
 123         0x57, 0x00, 0x4d, 0x00, 0x2f, 0x00, 0x41, 0x00,
 124         0x6c, 0x00, 0x62, 0x00, 0x75, 0x00, 0x6d, 0x00,
 125         0x54, 0x00, 0x69, 0x00, 0x74, 0x00, 0x6c, 0x00,
 126         0x65, 0x00
 127 };
 128
 129 static void read_asf_tags(const char *buf, int buf_size, struct taginfo *ti)
 130 {
 131         const char *p, *end = buf + buf_size;
 132         char tag[255];
 133
 134         p = search_pattern(comment_header, sizeof(comment_header),
 135                 buf, buf_size);
 136         if (p) {
 137                 int len1, len2, len3, len4, len5;
 138                 p += 24;
 139                 len1 = read_u16(p);
 140                 p += 2;
 141                 len2 = read_u16(p);
 142                 p += 2;
 143                 len3 = read_u16(p);
 144                 p += 2;
 145                 len4 = read_u16(p);
 146                 p += 2;
 147                 len5 = read_u16(p);
 148                 p += 2;
 149                 /* TODO: Check len values */
 150                 get_str16(p, len1, tag, sizeof(tag));
 151                 ti->title = para_strdup(tag);
 152                 PARA_INFO_LOG("title: %s\n", tag);
 153                 get_str16(p + len1, len2, tag, sizeof(tag));
 154                 ti->artist = para_strdup(tag);
 155                 PARA_INFO_LOG("artist: %s\n", tag);
 156                 get_str16(p + len1 + len2 + len3 + len4, len5, tag, sizeof(tag));
 157                 ti->comment = para_strdup(tag);
 158                 PARA_INFO_LOG("comment: %s\n", tag);
 159         } else
 160                 PARA_NOTICE_LOG("comment header not found\n");
 161         p = search_pattern(extended_content_header, sizeof(extended_content_header),
 162                 buf, buf_size);
 163         if (p) {
 164                 const char *q;
 165
 166                 q = search_pattern(year_tag_header, sizeof(year_tag_header),
 167                         p, end - p);
 168                 if (q) {
 169                         const char *r = q + sizeof(year_tag_header) + 6;
 170                         get_str16(r, end - r, tag, sizeof(tag));
 171                         ti->year = para_strdup(tag);
 172                         PARA_INFO_LOG("year: %s\n", tag);
 173                 }
 174                 q = search_pattern(album_tag_header, sizeof(album_tag_header),
 175                         p, end - p);
 176                 if (q) {
 177                         const char *r = q + sizeof(album_tag_header) + 6;
 178                         get_str16(r, end - r, tag, sizeof(tag));
 179                         ti->album = para_strdup(tag);
 180                         PARA_INFO_LOG("album: %s\n", tag);
 181                 }
 182                 return;
 183         } else
 184                 PARA_NOTICE_LOG("extended content header not found\n");
 185
 186 }
 187
 188 static int wma_make_chunk_table(char *buf, size_t buf_size, int block_align,
 189                 struct afh_info *afhi)
 190 {
 191         const uint8_t *f, *start = (uint8_t *)buf;
 192         int i, j, frames_per_chunk, chunk_time;
 193         size_t ct_size = 250;
 194         int count = 0, num_frames;
 195
 196         afhi->chunk_table = para_malloc(ct_size * sizeof(uint32_t));
 197         afhi->chunk_table[0] = 0;
 198         afhi->chunk_table[1] = afhi->header_len;
 199
 200         num_frames = count_frames(buf, buf_size, block_align,
 201                 &afhi->chunks_total);
 202         PARA_INFO_LOG("%d frames\n", num_frames);
 203         afhi->seconds_total = num_frames * 2048 /* FIXME */
 204                 / afhi->frequency;
 205         frames_per_chunk = num_frames / afhi->chunks_total;
 206         i = 0;
 207         j = 1;
 208         FOR_EACH_FRAME(f, start, buf_size, block_align) {
 209                 count += f[WMA_FRAME_SKIP] & 0x0f;
 210                 while (count > j * frames_per_chunk && f > start) {
 211                         j++;
 212                         if (j >= ct_size) {
 213                                 ct_size *= 2;
 214                                 afhi->chunk_table = para_realloc(
 215                                         afhi->chunk_table,
 216                                         ct_size * sizeof(uint32_t));
 217                         }
 218                         PARA_DEBUG_LOG("ct[%d]: %zu\n", j, f - start);
 219                         afhi->chunk_table[j] = f - start;
 220                 }
 221         }
 222         afhi->chunks_total = j;
 223         chunk_time = num_frames * 1000 / afhi->frequency * 2048
 224                 / afhi->chunks_total;
 225         PARA_INFO_LOG("ct: %d\n", chunk_time);
 226         afhi->chunk_tv.tv_sec = chunk_time / 1000;
 227         afhi->chunk_tv.tv_usec = (chunk_time % 1000) * 1000;
 228         //set_chunk_tv(num_frames, j, afhi->frequency, &afhi->chunk_tv);
 229         return 1;
 230 }
 231
 232 static int wma_get_file_info(char *map, size_t numbytes, __a_unused int fd,
 233         struct afh_info *afhi)
 234 {
 235         int ret;
 236         struct asf_header_info ahi;
 237
 238         ret = read_asf_header(map, numbytes, &ahi);
 239         if (ret < 0)
 240                 return ret;
 241         afhi->bitrate = ahi.bit_rate / 1000;
 242         afhi->frequency = ahi.sample_rate;
 243         afhi->channels = ahi.channels;
 244         afhi->header_len = ahi.header_len;
 245         afhi->header_offset = 0;
 246         read_asf_tags(map, ahi.header_len, &afhi->tags);
 247         wma_make_chunk_table(map + ahi.header_len, numbytes - ahi.header_len,
 248                 ahi.block_align, afhi);
 249         return 0;
 250 }
 251
 252 static const char* wma_suffixes[] = {"wma", NULL};
 253
 254 /**
 255  * The init function of the wma audio format handler.
 256  *
 257  * \param afh Pointer to the struct to initialize.
 258  */
 259 void wma_afh_init(struct audio_format_handler *afh)
 260 {
 261         afh->get_file_info = wma_get_file_info;
 262         afh->suffixes = wma_suffixes;
 263 }