/*
- * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2008 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.
+ * Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file filter.h filter-related structures and exported symbols from filter_chain.c */
+/** \file filter.h Filter-related structures and exported symbols from filter_chain.c. */
+
/**
- * describes one running instance of a chain of filters
- *
- */
-struct filter_chain {
+ * Describes one running instance of a filter.
+*/
+struct filter_node {
+ /** The number in the array of available filters. */
+ unsigned filter_num;
+ /** The filter chain this filter node belongs to. */
+ struct filter_chain *fc;
/**
- *
- *
- * the number of channels of the current stream
- *
- * Set by the decoding filter
+ * Each filter may store any filter-specific information about the particular
+ * instance of the filter here.
*/
- unsigned int channels;
+ void *private_data;
+ /** The output buffer. */
+ char *buf;
+ /** The size of the output buffer. */
+ size_t bufsize;
+ /** The number of bytes currently loaded in \a buf. */
+ size_t loaded;
+ /** The list of registered callbacks. */
+ struct list_head callbacks;
+ /** A pointer to the configuration of this instance. */
+ void *conf;
+};
+
+/** Describes one running instance of a chain of filters */
+struct filter_chain {
+ unsigned int num_filters;
/**
+ * The number of channels of the current stream.
*
- *
- * current samplerate in Hz
- *
- * Set by the decoding filter
+ * Set by the decoding filter.
*/
- unsigned int samplerate;
+ unsigned int channels;
/**
+ * Current sample rate in Hz.
*
- *
- * the list containing all filter nodes in this filter chain
+ * Set by the decoding filter.
*/
- struct list_head filters;
+ unsigned int samplerate;
+ /** The list containing all filter nodes in this filter chain. */
+ struct filter_node *filter_nodes;
/**
- *
- *
- * the input buffer of the filter chain
+ * The input buffer of the filter chain.
*
* This is set to point to the output buffer of the receiving application (the
* buffer used to read from stdin for para_filter; the output buffer of the
- * current receiver for para_audiod)
- */
- char *inbuf;
- /**
- *
- *
- * the output buffer of the filter chain
- *
- * Points to the output buffer of the last filter in the filter chain
- **/
- char *outbuf;
- /**
- *
- *
- * pointer to variable containing the number of bytes loaded in the input buffer
+ * current receiver for para_audiod).
*/
- size_t *in_loaded;
+ char *inbuf;
/**
+ * The output buffer of the filter chain.
*
- *
- * pointer to variable containing the number of bytes loaded in the output buffer
+ * Points to the output buffer of the last filter in the filter chain.
*/
- size_t *out_loaded;
- /** non-zero if this filter wont' produce any more output */
- int eof;
- /** pointer to the eof flag of the receiving application */
- int *reader_eof;
- /** the task associated with the filter chain */
+ char *outbuf;
+ /** Contains the number of bytes loaded in the input buffer. */
+ size_t *in_loaded;
+ /** Contains the number of bytes loaded in the output buffer. */
+ size_t *out_loaded;
+ /** Pointer to the error variable of the receiving application. */
+ int *input_error;
+ /** Pointer to the error variable of the writing application. */
+ int *output_error;
+ /** The task associated with the filter chain. */
struct task task;
};
-/**
- * describes one running instance of a filter
-*/
-struct filter_node {
-/**
- *
- *
- * a pointer to the corresponding filter struct
- */
- struct filter *filter;
-/**
- *
- *
- * the filter chain this filter node belongs to
- */
- struct filter_chain *fc;
-/**
- *
- *
- * the position of the filter in the corresponding filter chain
- *
- * all filters that make up the filter chains are organized in a doubly
- * linked list.
- */
- struct list_head node;
-/**
- *
- *
- * each filter may store any filter-specific information about the particular
- * instance of the filter here.
- */
- void *private_data;
-/**
- *
- *
- * the output buffer
- */
- char *buf;
-/**
- * the size of the output buffer
- */
- size_t bufsize;
-/**
- *
- *
- * the number of bytes currently loaded in \a buf
- */
- size_t loaded;
-/**
- *
- *
- * the list of registered callbacks
- */
- struct list_head callbacks;
-/**
- *
- * a pointer to the configuration of this instance
- */
- void *conf;
-};
+#define FOR_EACH_FILTER_NODE(fn, fc, i) for (i = 0; i < (fc)->num_filters \
+ && (fn = (fc)->filter_nodes + i); i++)
+
/**
- * used to manage grab clients
+ * Used to manage grab clients.
*
* An application using paraslash's filter subsystem may register any number of
* callbacks for each filter_node. It is possible to attach a filter callback
* the grab command.
*/
struct filter_callback {
-/**
- *
- *
- * all callbacks are organized in a doubly linked list
- */
+ /** All callbacks are organized in a doubly linked list. */
struct list_head node;
-/**
- *
- *
- * private data
- *
- * May be initialized by the application before registering the callback. This
- * pointer is not used by the filter subsystem. It is provided for use within
- * the input/ouput/close callback functions.
- */
+ /**
+ * Private data.
+ *
+ * May be initialized by the application before registering the callback. This
+ * pointer is not used by the filter subsystem. It is provided for use within
+ * the input/output/close callback functions.
+ */
void *data;
-/**
- *
- *
- * the input callback
- *
- * In not \p NULL, the filter subsystem calls this function whenever the filter
- * consumed some or all of its input buffer. A pointer to the buffer of consumed
- * data, its length and a pointer to the own \a filter_callback structure are passed
- * to \a input_cb. The input callback is expected to return a negative value on errors.
- */
+ /**
+ * The input callback.
+ *
+ * In not \p NULL, the filter subsystem calls this function whenever the filter
+ * consumed some or all of its input buffer. A pointer to the buffer of consumed
+ * data, its length and a pointer to the own \a filter_callback structure are passed
+ * to \a input_cb. The input callback is expected to return a negative value on errors.
+ */
int (*input_cb)(char *buf, size_t len, struct filter_callback *fc);
-/**
- *
- *
- * the output callback
- *
- * If not NULL, this is called whenever the filter produces output. A pointer
- * to the output data, its length and a pointer to the own \a filter_callback
- * structure are passed to \a output_cb. Like the input callback, the output
- * callback is expected to return a negative value on errors.
- */
+ /**
+ * The output callback.
+ *
+ * If not NULL, this is called whenever the filter produces output. A pointer
+ * to the output data, its length and a pointer to the own \a filter_callback
+ * structure are passed to \a output_cb. Like the input callback, the output
+ * callback is expected to return a negative value on errors.
+ */
int (*output_cb)(char *buf, size_t len, struct filter_callback *fc);
-/**
- *
- *
- * the callback close function
- *
- * This gets called whenever the input/ouput callback returned an error, or if
- * the filter chain is going to be destroyed, e.g. because the end of the
- * stream was encounterd. It is assumed to succeed.
- */
+ /**
+ * The callback close function.
+ *
+ * This gets called whenever the input/output callback returned an error, or if
+ * the filter chain is going to be destroyed, e.g. because the end of the
+ * stream was encountered. It is assumed to succeed.
+ */
void (*close)(struct filter_callback *fc);
};
-void close_filters(struct filter_chain *fc);
-int filter_io(struct filter_chain *fc);
-void filter_init(struct filter *all_filters);
-int check_filter_arg(char *filter_arg, void **conf);
-int del_filter_callback(struct filter_callback *fcb);
-void filter_pre_select(struct sched *s, struct task *t);
-
/**
- * the structure associated with a paraslash filter
+ * The structure associated with a paraslash filter.
*
* Paraslash filters are "modules" which are used to transform an audio stream.
* struct filter contains pointers to functions that must be supplied by the
* \sa mp3dec.c, oggdec.c, wav.c, compress.c, filter_node
*/
struct filter {
-/**
- *
- *
- * the name of the filter
- */
-const char *name;
-/**
- *
- *
- * pointer to the filter init routine
- *
- * This function is only called once at startup. It must initialize the
- * other non-optional function pointers of \a f.
- */
-void (*init)(struct filter *f);
-/**
- *
- *
- * open one instance of this filter
- *
- * This should allocate the output buffer of the given filter node and do any
- * other filter-specific preparations like initializing the private_data member
- * of \a fn suitably. The open function is assumed to succeed.
- */
-void (*open)(struct filter_node *fn);
-/**
- *
- *
- * convert (filter) the given data
- *
- * Pointer to the converting function of the filter. It should convert the
- * given input buffer \a inbuf which is of length \a len to the previoulsy
- * reserved output buffer of \a fn. On success, it must return the number of
- * bytes it consumed from \a inbuf. On errors, a negative number indicating the
- * kind of the error must be returned.
- *
- * A zero return value just means that nothing was converted (probably because
- * the input buffer was too small). This is not interpreted as an error.
- */
-ssize_t (*convert)(char *inbuf, size_t len, struct filter_node *fn);
-/**
- *
- *
- * close one instance of this filter
- *
- * Free all resources of associated with \a fn that were previously allocated
- * by the open() function.
- */
-void (*close)(struct filter_node *fn);
-/**
- *
- *
- * print the help text for this filter and exit
- *
- * This is optional and it is not necessary to initialize this pointer if
- * the filter does not have a help text.
- */
-void (*print_help)(void);
-/**
- *
- *
- * a pointer to the filter's command line parser
- *
- * If this optional function pointer is not NULL, any filter options are passed
- * from the main propgram to this command line parser once at application
- * startup. The command line parser should check its command line options given
- * by \a argc and \a argv and abort on errors. On success, it should return a
- * pointer to the filter-specific configuration data determined by \a argc and
- * \a argv.
- */
-void *(*parse_config)(int argc, char **argv);
+ /** The name of the filter. */
+ const char *name;
+ /**
+ * Pointer to the filter init routine.
+ *
+ * This function is only called once at startup. It must initialize the
+ * other non-optional function pointers of this structure.
+ */
+ void (*init)(struct filter *f);
+ /**
+ * Open one instance of this filter.
+ *
+ * This should allocate the output buffer of the given filter node and do any
+ * other filter-specific preparations like initializing the private_data member
+ * of \a fn suitably. The open function is assumed to succeed.
+ */
+ void (*open)(struct filter_node *fn);
+ /**
+ * Convert (filter) the given data.
+ *
+ * Pointer to the converting function of the filter. It should convert the
+ * given input buffer \a inbuf which is of length \a len to the previously
+ * reserved output buffer of \a fn. On success, it must return the number of
+ * bytes it consumed from \a inbuf. On errors, a negative number indicating the
+ * kind of the error must be returned.
+ *
+ * A zero return value just means that nothing was converted (probably because
+ * the input buffer was too small). This is not interpreted as an error.
+ */
+ ssize_t (*convert)(char *inbuf, size_t len, struct filter_node *fn);
+ /**
+ * Close one instance of this filter.
+ *
+ * Free all resources of associated with \a fn that were previously allocated
+ * by the open() function.
+ */
+ void (*close)(struct filter_node *fn);
+ /**
+ * Print the help text for this filter and exit.
+ *
+ * This is optional and it is not necessary to initialize this pointer if
+ * the filter does not have a help text.
+ */
+ void (*print_help)(void);
+ /**
+ * A pointer to the filter's command line parser.
+ *
+ * If this optional function pointer is not NULL, any filter options are passed
+ * from the main program to this command line parser once at application
+ * startup. The command line parser should check its command line options given
+ * by \a argc and \a argv and abort on errors. On success, it should return a
+ * pointer to the filter-specific configuration data determined by \a argc and
+ * \a argv.
+ */
+ void *(*parse_config)(int argc, char **argv);
};
+
+void close_filters(struct filter_chain *fc);
+void filter_init(struct filter *all_filters);
+int check_filter_arg(char *filter_arg, void **conf);
+void filter_pre_select(__a_unused struct sched *s, struct task *t);
+
+
+static inline void write_int16_host_endian(char *buf, int val)
+{
+#ifdef WORDS_BIGENDIAN
+ *buf = val >> 8;
+ *(buf + 1) = val & 0xff;
+#else
+ *buf = val & 0xff;
+ *(buf + 1) = val >> 8;
+#endif
+}
+
+
/** \cond */
extern struct filter filters[];
#define DECLARE_EXTERN_FILTER_INIT(name) \
/* filters that are always present */
DECLARE_EXTERN_FILTER_INIT(wav);
-/* wav is always the first filter */
-#define WAV_FILTER_NUM 0
DECLARE_EXTERN_FILTER_INIT(compress);
/* next the optional filters */
#else
#define OGGDEC_FILTER
#endif
+/** \endcond */
-/*
- * a macro that defines an array of all available filters
- */
-#define DEFINE_FILTER_ARRAY(fa) struct filter fa[] = { \
+/** define an array of all available filters */
+#define DEFINE_FILTER_ARRAY(filters) struct filter filters[] = { \
FILTER_INIT(wav) \
FILTER_INIT(compress) \
MP3DEC_FILTER \
AACDEC_FILTER \
OGGDEC_FILTER \
{ .name = NULL } };
-/** \endcond */
+
+
projects / paraslash.git / blobdiff