afh.h

   1 /*
   2  * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file afh.h structures for audio format handling (para_server) */
   8
   9 /** \cond */
  10 #ifdef HAVE_OGGVORBIS
  11 #define OV_AUDIO_FORMAT " ogg"
  12 #else
  13 #define OV_AUDIO_FORMAT ""
  14 #endif
  15
  16 #ifdef HAVE_FAAD
  17 #define AAC_AUDIO_FORMAT " aac"
  18 #else
  19 #define AAC_AUDIO_FORMAT ""
  20 #endif
  21
  22 #define SUPPORTED_AUDIO_FORMATS "mp3" OV_AUDIO_FORMAT AAC_AUDIO_FORMAT
  23
  24 /** \endcond */
  25
  26 /** Audio format dependent information. */
  27 struct afh_info {
  28         /** The number of chunks this audio file contains. */
  29         long unsigned chunks_total;
  30         /** The length of the audio file in seconds. */
  31         long unsigned seconds_total;
  32         /** A string that gets filled in by the audio format handler. */
  33         char *info_string;
  34         /**
  35          * The table that specifies the offset of the individual pieces in
  36          * the current audio file.
  37          */
  38         uint32_t *chunk_table;
  39         /** Period of time between sending data chunks. */
  40         struct timeval chunk_tv;
  41         /** End of file timeout - Do not load new audio file until this time. */
  42         struct timeval eof_tv;
  43         /**
  44          * The position of the header within the audio file. Ignored if \a
  45          * header_len equals zero.
  46          */
  47         uint32_t header_offset;
  48         /**
  49          * The header is needed by senders in case a new client connects in the
  50          * middle of the stream. The length of the header defaults to zero
  51          * which means that this audio format does not need any special header
  52          * treatment. The audio format handler does not need to set this to
  53          * zero in this case.
  54          */
  55         uint32_t header_len;
  56         /** The number of channels. */
  57         uint8_t channels;
  58         /** Frequency in Hz. */
  59         uint16_t frequency;
  60         /** Exact meaning depends on audio format. */
  61         uint16_t bitrate;
  62 };
  63
  64 /**
  65  *  Structure for audio format handling.
  66  *
  67  *  There's one such struct for each supported audio format. Initially, only \a
  68  *  name and \a init are defined. During the startup process, para_server calls
  69  *  the \a init function of each audio format handler which is expected to fill
  70  *  in the other part of this struct.
  71  */
  72 struct audio_format_handler {
  73         /** Name of the audio format. */
  74         const char *name;
  75         /**
  76          * Pointer to the audio format handler's init function.
  77          *
  78          * Must initialize all function pointers and is assumed to succeed.
  79          */
  80         void (*init)(struct audio_format_handler*);
  81         /** Typical file endings for files that can be handled by this afh. */
  82         const char **suffixes;
  83         /**
  84          * Check if this audio format handler can handle the file.
  85          *
  86          * This is a  pointer to a function returning whether a given file is
  87          * valid for this audio format. A negative return value indicates that
  88          * this audio format handler is unable to decode the given file. On
  89          * success, the function must return a positive value and fill in the
  90          * given struct afh_info.
  91          *
  92          * \sa struct afh_info
  93          */
  94         int (*get_file_info)(char *map, size_t numbytes, int fd,
  95                 struct afh_info *afi);
  96 };
  97
  98 void afh_init(void);
  99 int guess_audio_format(const char *name);
 100 int compute_afhi(const char *path, char *data, size_t size,
 101         int fd, struct afh_info *afhi);
 102 const char *audio_format_name(int);
 103 void afh_get_chunk(long unsigned chunk_num, struct afh_info *afhi,
 104                 void *map, const char **buf, size_t *len);
 105 uint32_t afh_get_largest_chunk_size(struct afh_info *afhi);
 106 void afh_get_header(struct afh_info *afhi, void *map, const char **buf, size_t *len);
 107 char *make_taginfo(char *title, char *artist, char *album, char *year,
 108                 char *comment);