+/*
+ * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ */
+
+/** \file afh.h structures for audio format handling (para_server) */
+
+/** \cond */
+#ifdef HAVE_OGGVORBIS
+#define OV_AUDIO_FORMAT " ogg"
+#define OV_AUDIO_FORMAT_ARRAY , "ogg"
+#else
+#define OV_AUDIO_FORMAT ""
+#define OV_AUDIO_FORMAT_ARRAY
+#endif
+
+#ifdef HAVE_FAAD
+#define AAC_AUDIO_FORMAT " aac"
+#define AAC_AUDIO_FORMAT_ARRAY , "aac"
+#else
+#define AAC_AUDIO_FORMAT ""
+#define AAC_AUDIO_FORMAT_ARRAY
+#endif
+
+#define SUPPORTED_AUDIO_FORMATS "mp3" OV_AUDIO_FORMAT AAC_AUDIO_FORMAT
+#define SUPPORTED_AUDIO_FORMATS_ARRAY "mp3" OV_AUDIO_FORMAT_ARRAY \
+ AAC_AUDIO_FORMAT_ARRAY, NULL
+
+/** \endcond */
+
+/**
+ * structure for audio format handling
+ *
+ * There's exactly one such struct for each supported audio format. Initially,
+ * only \a name and \a init are defined. During the startup process,
+ * para_server calls the \a init function of each audio format handler which is
+ * expected to fill in all the other function pointers.
+ */
+struct audio_format_handler {
+ /**
+ * name of the audio format
+ */
+ const char *name;
+ /**
+ * typical file endings for files that can be handled by this afh.
+ */
+ const char **suffixes;
+ /**
+ * pointer to the audio format handler's init function
+ *
+ * Must initialize all function pointers and is assumed to succeed.
+ */
+ void (*init)(struct audio_format_handler*);
+ /**
+ * period of time between sending data chunks
+ */
+ struct timeval chunk_tv; /* length of one chunk of data */
+ /**
+ * end of file timeout - do not load new audio file until this time
+ *
+ */
+ struct timeval eof_tv; /* timeout on eof */
+ /**
+ * Pointer to the optional get-header function.
+ *
+ * This is called from a sender in case a new client connects in the middle of
+ * the stream. The audio format handler may set this to NULL to indicate that
+ * this audio format does not need any special header treatment. If non-NULL,
+ * the function it points to must return a pointer to a buffer holding the
+ * current audio file header, together with the header length.
+ */
+ char *(*get_header_info)(int *header_len);
+ /**
+ * check if this audio format handler can handle the file
+ *
+ * This is a pointer to a function returning whether a given file is valid for
+ * this audio format. A negative return value indicates that this audio format
+ * handler did not recognize the given file. On success, the function is
+ * expected to return a positive value and to fill in \arg info_str, \arg
+ * chunks and \arg seconds appropriately.
+ */
+ int (*get_file_info)(FILE *audio_file, char *info_str,
+ long unsigned *chunks, int *seconds);
+ /**
+ * cleanup function of this audio format handler
+ *
+ * This close function should deallocate any resources
+ * associated with the current audio file. In particular, it is responsible
+ * for closing the file handle. It is assumed to succeed.
+ */
+ void (*close_audio_file)(void);
+ /**
+ * jump to another position in the current audio file
+ *
+ * This is called if a client issued the ff or jmp command with \a request
+ * being the number of the next chunk that should be sent out. Must return a
+ * positive value on success and a negative value on errors.
+ */
+ int (*reposition_stream)(long unsigned request);
+ /**
+ * function responsible for reading one data chunk.
+ *
+ * \a read_chunk() must return a pointer to the next chunk of data that should
+ * be sent out, or \p NULL on errors or if the end of the file was encountered.
+ *
+ * If it returns non-NULL, \a len must contain the length of the returned
+ * buffer (which may be zero if nothing has to be sent for some reason).
+ * Otherwise, \a len is used to distinguish between the eof and the error case:
+ * It must be zero in the eof case, or negative if an error occcured.
+ */
+ char * (*read_chunk)(long unsigned chunk_num, ssize_t *len);
+};