afh_common.c

   1 /*
   2  * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file afh_common.c Common audio format handler functions. */
   8
   9 #include <sys/mman.h> /* mmap */
  10 #include <sys/time.h> /* gettimeofday */
  11 #include <sys/types.h>
  12 #include <dirent.h>
  13
  14 #include "para.h"
  15 #include "error.h"
  16 #include "string.h"
  17 #include "afh.h"
  18
  19 /* The mp3 audio format handler does not need any libs. */
  20 void mp3_init(struct audio_format_handler *);
  21
  22 #ifdef HAVE_OGGVORBIS
  23         void ogg_init(struct audio_format_handler *);
  24 #endif
  25 #ifdef HAVE_FAAD
  26         void aac_afh_init(struct audio_format_handler *);
  27 #endif
  28
  29 /**
  30  * The list of supported audio formats.
  31  *
  32  * We always define the full array of audio formats even if some audio formats
  33  * were not compiled in. This is because for each audio file the number of its
  34  * audio format is stored in the database. We don't want that numbers to become
  35  * stale just because the user installed a new version of paraslash that
  36  * supports a different set of audio formats.
  37  *
  38  * It can still be easily detected whether an audio format is compiled in by
  39  * checking if the init function pointer is not \p NULL.
  40  */
  41 static struct audio_format_handler afl[] = {
  42         {
  43                 .name = "mp3",
  44                 .init = mp3_init,
  45         },
  46         {
  47                 .name = "ogg",
  48 #ifdef HAVE_OGGVORBIS
  49                 .init = ogg_init,
  50 #endif
  51         },
  52         {
  53                 .name = "aac",
  54 #ifdef HAVE_FAAD
  55                 .init = aac_afh_init,
  56 #endif
  57         },
  58         {
  59                 .name = NULL,
  60         }
  61 };
  62
  63 static inline int next_audio_format(int format)
  64 {
  65         for (;;) {
  66                 if (!afl[format].name)
  67                         return format;
  68                 format++;
  69                 if (afl[format].init)
  70                         return format;
  71         }
  72
  73 }
  74
  75 /** Iterate over each supported audio format. */
  76 #define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))
  77
  78 /**
  79  * Call the init function of each supported audio format handler.
  80  */
  81 void afh_init(void)
  82 {
  83         int i;
  84
  85         PARA_INFO_LOG("supported audio formats: %s\n",
  86                 SUPPORTED_AUDIO_FORMATS);
  87         FOR_EACH_AUDIO_FORMAT(i) {
  88                 PARA_NOTICE_LOG("initializing %s handler\n",
  89                         audio_format_name(i));
  90                 afl[i].init(&afl[i]);
  91         }
  92 }
  93
  94
  95 /**
  96  * Guess the audio format judging from filename.
  97  *
  98  * \param name The filename.
  99  *
 100  * \return This function returns -1 if it has no idea what kind of audio
 101  * file this might be. Otherwise the (non-negative) number of the audio format
 102  * is returned.
 103  */
 104 int guess_audio_format(const char *name)
 105 {
 106         int i,j, len = strlen(name);
 107
 108         FOR_EACH_AUDIO_FORMAT(i) {
 109                 for (j = 0; afl[i].suffixes[j]; j++) {
 110                         const char *p = afl[i].suffixes[j];
 111                         int plen = strlen(p);
 112                         if (len < plen + 1)
 113                                 continue;
 114                         if (name[len - plen - 1] != '.')
 115                                 continue;
 116                         if (strcasecmp(name + len - plen, p))
 117                                 continue;
 118 //                      PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
 119                         return i;
 120                 }
 121         }
 122         return -1;
 123 }
 124
 125 /**
 126  * Call get_file_info() to obtain an afhi structure.
 127  *
 128  * \param path The full path of the audio file.
 129  * \param data Pointer to the contents of the (mapped) file.
 130  * \param size The file size in bytes.
 131  * \param fd The open file descriptor.
 132  * \param afhi Result pointer.
 133  *
 134  * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
 135  * compiled in audio format handler is able to handler the file.
 136  *
 137  * This function tries to find an audio format handler that can interpret the
 138  * file given by \a data and \a size.
 139  *
 140  * It first tries to determine the audio format from the filename given by \a
 141  * path. If this doesn't work, all other audio format handlers are tried until
 142  * one is found that can handle the file.
 143  */
 144 int compute_afhi(const char *path, char *data, size_t size, int fd,
 145                 struct afh_info *afhi)
 146 {
 147         int ret, i, format;
 148
 149         afhi->header_offset = 0;
 150         afhi->header_len = 0;
 151         format = guess_audio_format(path);
 152
 153         if (format >= 0) {
 154                 ret = afl[format].get_file_info(data, size, fd, afhi);
 155                 if (ret >= 0)
 156                         return format;
 157         }
 158         FOR_EACH_AUDIO_FORMAT(i) {
 159                 if (i == format) /* we already tried this one to no avail */
 160                         continue;
 161                 ret = afl[i].get_file_info(data, size, fd, afhi);
 162                 if (ret >= 0)
 163                         return i;
 164                 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
 165         }
 166         return -E_AUDIO_FORMAT;
 167 }
 168
 169 /**
 170  * Get the name of the given audio format.
 171  *
 172  * \param i The audio format number.
 173  *
 174  * This returns a pointer to statically allocated memory so it
 175  * must not be freed by the caller.
 176  */
 177 const char *audio_format_name(int i)
 178 {
 179         //PARA_NOTICE_LOG("array size: %u¸ requested: %d\n", ARRAY_SIZE(afl), i);
 180         assert(i < 0 || i < ARRAY_SIZE(afl) - 1);
 181         return i >= 0?  afl[i].name : "(none)";
 182 }
 183
 184
 185 void afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
 186                 void *map, const char **buf, size_t *len)
 187 {
 188         size_t pos = afhi->chunk_table[chunk_num];
 189         *buf = map + pos;
 190         *len = afhi->chunk_table[chunk_num + 1] - pos;
 191 }
 192
 193 /**
 194  * Get the header of an audio file.
 195  *
 196  * \param afhi The audio file handler data describing the file.
 197  * \param map The data of the audio file.
 198  * \param buf The length of the header is stored here.
 199  * \param len Points to a buffer containing the header on return.
 200  *
 201  * This function sets \a buf to \p NULL and \a len to zero if \a map or \a
 202  * afhi is \p NULL, or if the current audio format does not need special
 203  * header treamtment.
 204  */
 205 void afh_get_header(struct afh_info *afhi, void *map, const char **buf, size_t *len)
 206 {
 207         if (!map || !afhi || ! afhi->header_len) {
 208                 *buf = NULL;
 209                 *len = 0;
 210         }
 211         *len = afhi->header_len;
 212         *buf = map + afhi->header_offset;
 213 }