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Diffstat (limited to 'trunk/include/asterisk/mod_format.h')
| -rw-r--r-- | trunk/include/asterisk/mod_format.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/trunk/include/asterisk/mod_format.h b/trunk/include/asterisk/mod_format.h new file mode 100644 index 000000000..c51bf681c --- /dev/null +++ b/trunk/include/asterisk/mod_format.h @@ -0,0 +1,144 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 1999 - 2006, Digium, Inc. + * + * Mark Spencer <markster@digium.com> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/*! \file + * \brief Header for providers of file and format handling routines. + * Clients of these routines should include "asterisk/file.h" instead. + */ + +#ifndef _ASTERISK_MOD_FORMAT_H +#define _ASTERISK_MOD_FORMAT_H + +#include "asterisk/file.h" +#include "asterisk/frame.h" + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +/*! \brief + * Each supported file format is described by the following structure. + * + * Not all are necessary, the support routine implement default + * values for some of them. + * A handler typically fills a structure initializing the desired + * fields, and then calls ast_format_register() with the (readonly) + * structure as an argument. + */ +struct ast_format { + char name[80]; /*!< Name of format */ + char exts[80]; /*!< Extensions (separated by | if more than one) + this format can read. First is assumed for writing (e.g. .mp3) */ + int format; /*!< Format of frames it uses/provides (one only) */ + /*! + * \brief Prepare an input stream for playback. + * \return 0 on success, -1 on error. + * The FILE is already open (in s->f) so this function only needs to perform + * any applicable validity checks on the file. If none is required, the + * function can be omitted. + */ + int (*open)(struct ast_filestream *s); + /*! + * \brief Prepare a stream for output, and comment it appropriately if applicable. + * \return 0 on success, -1 on error. + * Same as the open, the FILE is already open so the function just needs to + * prepare any header and other fields, if any. + * The function can be omitted if nothing is needed. + */ + int (*rewrite)(struct ast_filestream *s, const char *comment); + /*! Write a frame to a channel */ + int (*write)(struct ast_filestream *, struct ast_frame *); + /*! seek num samples into file, whence - like a normal seek but with offset in samples */ + int (*seek)(struct ast_filestream *, off_t, int); + int (*trunc)(struct ast_filestream *fs); /*!< trunc file to current position */ + off_t (*tell)(struct ast_filestream *fs); /*!< tell current position */ + /*! Read the next frame from the filestream (if available) and report + * when to get next frame (in samples) + */ + struct ast_frame * (*read)(struct ast_filestream *, int *whennext); + /*! Do any closing actions, if any. The descriptor and structure are closed + * and destroyed by the generic routines, so they must not be done here. */ + void (*close)(struct ast_filestream *); + char * (*getcomment)(struct ast_filestream *); /*!< Retrieve file comment */ + + AST_LIST_ENTRY(ast_format) list; /*!< Link */ + + /*! + * If the handler needs a buffer (for read, typically) + * and/or a private descriptor, put here the + * required size (in bytes) and the support routine will allocate them + * for you, pointed by s->buf and s->private, respectively. + * When allocating a buffer, remember to leave AST_FRIENDLY_OFFSET + * spare bytes at the bginning. + */ + int buf_size; /*!< size of frame buffer, if any, aligned to 8 bytes. */ + int desc_size; /*!< size of private descriptor, if any */ + + struct ast_module *module; +}; + +/*! \brief + * This structure is allocated by file.c in one chunk, + * together with buf_size and desc_size bytes of memory + * to be used for private purposes (e.g. buffers etc.) + */ +struct ast_filestream { + /*! Everybody reserves a block of AST_RESERVED_POINTERS pointers for us */ + struct ast_format *fmt; /* need to write to the lock and usecnt */ + int flags; + mode_t mode; + char *filename; + char *realfilename; + /*! Video file stream */ + struct ast_filestream *vfs; + /*! Transparently translate from another format -- just once */ + struct ast_trans_pvt *trans; + struct ast_tranlator_pvt *tr; + int lastwriteformat; + int lasttimeout; + struct ast_channel *owner; + FILE *f; + struct ast_frame fr; /*!< frame produced by read, typically */ + char *buf; /*!< buffer pointed to by ast_frame; */ + void *_private; /*!< pointer to private buffer */ + const char *orig_chan_name; +}; + +/*! + * \brief Register a new file format capability. + * Adds a format to Asterisk's format abilities. + * \retval 0 on success + * \retval -1 on failure + */ +int __ast_format_register(const struct ast_format *f, struct ast_module *mod); +#define ast_format_register(f) __ast_format_register(f, ast_module_info->self) + +/*! + * \brief Unregisters a file format + * \param name the name of the format you wish to unregister + * Unregisters a format based on the name of the format. + * \retval 0 on success + * \retval -1 on failure to unregister + */ +int ast_format_unregister(const char *name); + +#if defined(__cplusplus) || defined(c_plusplus) +} +#endif + +#endif /* _ASTERISK_MOD_FORMAT_H */ |