afh.h

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file afh.h structures for audio format handling (para_server) */
  20
  21 /** \cond */
  22 #ifdef HAVE_OGGVORBIS
  23 #define OV_AUDIO_FORMAT " ogg"
  24 #define OV_AUDIO_FORMAT_ARRAY , "ogg"
  25 #else
  26 #define OV_AUDIO_FORMAT ""
  27 #define OV_AUDIO_FORMAT_ARRAY
  28 #endif
  29
  30 #ifdef HAVE_FAAD
  31 #define AAC_AUDIO_FORMAT " aac"
  32 #define AAC_AUDIO_FORMAT_ARRAY , "aac"
  33 #else
  34 #define AAC_AUDIO_FORMAT ""
  35 #define AAC_AUDIO_FORMAT_ARRAY
  36 #endif
  37
  38 #define SUPPORTED_AUDIO_FORMATS "mp3" OV_AUDIO_FORMAT AAC_AUDIO_FORMAT
  39 #define SUPPORTED_AUDIO_FORMATS_ARRAY "mp3" OV_AUDIO_FORMAT_ARRAY \
  40         AAC_AUDIO_FORMAT_ARRAY, NULL
  41
  42 /** \endcond */
  43
  44 /** size of the  audio_file info string */
  45 #define AUDIO_FILE_INFO_SIZE 16384
  46
  47 struct audio_format_info {
  48         /** the number of chunks this audio file contains */
  49         long unsigned chunks_total;
  50         /** the length of the audio file in seconds */
  51         int seconds_total;
  52         /** a string that gets filled in by the audio format handler */
  53         char info_string[AUDIO_FILE_INFO_SIZE];
  54         /**
  55          * the table that specifies the offset of the individual pieces in
  56          * the current audio file.
  57          */
  58         size_t *chunk_table;
  59         /** period of time between sending data chunks */
  60         struct timeval chunk_tv;
  61         /** end of file timeout - do not load new audio file until this time */
  62         struct timeval eof_tv;
  63         /**
  64          * optional audio file header
  65          *
  66          * This is read from a sender in case a new client connects in the
  67          * middle of the stream.  The audio format handler does not need to set
  68          * this if the audio format does not need any special header treatment.
  69          * If non-NULL, it must point to a buffer holding the current audio
  70          * file header.
  71          */
  72         char *header;
  73         /** the length of the header, ignored if \a header is \p NULL */
  74         unsigned header_len;
  75 };
  76
  77 /**
  78  * structure for audio format handling
  79  *
  80  * There's exactly one such struct for each supported audio format. Initially,
  81  * only \a name and \a init are defined. During the startup process,
  82  * para_server calls the \a init function of each audio format handler which is
  83  * expected to fill in all the other function pointers.
  84  */
  85 struct audio_format_handler {
  86         /**
  87          * name of the audio format
  88          */
  89         const char *name;
  90         /**
  91          * typical file endings for files that can be handled by this afh.
  92          */
  93         const char **suffixes;
  94         /**
  95          * pointer to the audio format handler's init function
  96          *
  97          * Must initialize all function pointers and is assumed to succeed.
  98          */
  99         void (*init)(struct audio_format_handler*);
 100         /**
 101          * check if this audio format handler can handle the file
 102          *
 103          * This is a  pointer to a function returning whether a given file is
 104          * valid for this audio format. A negative return value indicates that
 105          * this audio format handler did not recognize the given file. On
 106          * success, the function must return a positive value and fill in the
 107          * given struct audio_format_info.
 108          *
 109          * \sa struct audio_format_info
 110         */
 111         int (*get_file_info)(FILE *audio_file, char *map, off_t numbytes,
 112                 struct audio_format_info *afi);
 113 };
 114