X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter.h;h=4537b2202c3d5cffdf5397553364fc67f23dc287;hp=0808059dac3f7450aaa73c27d6afd4d382c62e94;hb=a85b3b947174c64ce06b4d6e438677055bf3f1ae;hpb=b62e2796b85c7d7f3138fe729f4637853e0fafe0 diff --git a/filter.h b/filter.h index 0808059d..4537b220 100644 --- a/filter.h +++ b/filter.h @@ -1,14 +1,11 @@ /* - * Copyright (C) 2005-2011 Andre Noll + * Copyright (C) 2005 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ /** \file filter.h Filter-related structures and exported symbols from filter_common.c. */ -/** The list of supported filters. */ -enum filter_enum {FILTER_ENUM}; - /** * Describes one running instance of a filter. */ @@ -24,89 +21,88 @@ struct filter_node { struct list_head callbacks; /** A pointer to the configuration of this instance. */ void *conf; + /** The parsed command line, merged with options given in the config file. */ + struct lls_parse_result *lpr; + /** The buffer tree node. */ struct btr_node *btrn; - struct task task; + /** The task corresponding to this filter node. */ + struct task *task; + /** The minimal input queue size, see \ref btr_node_status(). */ size_t min_iqs; }; /** * 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 - * filter code in order to be used by the driving application (currently - * para_audiod and para_filter). + * Paraslash filters are "modules" which transform an audio stream. struct + * filter contains methods which are implemented by each filter. * * Note: As several instances of the same filter may be running at the same * time, all these filter functions must be reentrant; no static non-constant * variables may be used. + * * \sa mp3dec_filter.c, oggdec_filter.c, wav_filter.c, compress_filter.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 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. + * 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 + * optional, If it is provided, it is assumed to succeed. */ void (*open)(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. It's OK to leave this alone if the filter does not - * need any cleanups. + * Free all resources associated with \a fn that were previously + * allocated by the open() function. It's OK to set this to NULL if the + * filter does not need to perform any cleanup operation. */ void (*close)(struct filter_node *fn); /** - * A pointer to the filter's command line parser. + * Prepare the filter according to command line options. + * + * In addition to the syntactic checks which are automatically performed + * by the lopsub functions, some filters like to also check the command + * line arguments semantically. Moreover, since applications may open + * the filter many times with the same options, filters need a method + * which allows them to precompute once those parts of the setup which + * depend only on the command line options. * - * 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. Success must be indicated by a non-negative return value. In - * this case the function should return a pointer to the - * filter-specific configuration data determined by \a argc and \a - * argv. On failure, a negative paraslash error code must be returned. + * If this function pointer is not NULL, the function is called once at + * startup. The returned pointer value is made available to the ->open + * method via the ->conf pointer of struct filter_node. + * + * Filters are supposed to abort if the setup fails. If the function + * returns, it is assumed to have succeeded. */ - int (*parse_config)(int argc, char **argv, void **config); + void *(*setup)(const struct lls_parse_result *lpr); /** - * Deallocate the memory for the configuration. + * Deallocate precomputed resources. * - * This is called to free whatever ->parse_config() has allocated. + * This should free whatever ->setup() has allocated. */ - void (*free_config)(void *conf); - - /** The help texts for this filter. */ - struct ggo_help help; + void (*teardown)(const struct lls_parse_result *lpr, void *conf); /** * Set scheduler timeout and add file descriptors to fd sets. * - * This function is used to control the timeout value for select. It - * only allowed to decrease the current value. The second purpose of - * this function is to set file descriptors to be watched by the - * subsequent select call to the two fd sets. + * This function controls the timeout value for the next call to + * select(2). It may decrease the current timeout but shall never + * increase it. The second purpose of this function is to add file + * descriptors to the two fd sets of the sched structure. The + * descriptors in these sets will be watched by the subsequent + * select(2) call. */ - void (*pre_select)(struct sched *s, struct task *t); + void (*pre_select)(struct sched *s, void *context); /** * Convert (filter) the given data. * * Pointer to the converting function of the filter. On errors, the - * post_select function is supposed to set t->error to a (negative) - * error code. + * post_select function is supposed to return a negative error code. */ - void (*post_select)(struct sched *s, struct task *t); + int (*post_select)(struct sched *s, void *context); /** * Answer a buffer tree query. * @@ -116,10 +112,23 @@ struct filter { btr_command_handler execute; }; -void filter_init(void); -int check_filter_arg(char *filter_arg, void **conf); -void print_filter_helps(int detailed); -void generic_filter_pre_select(struct sched *s, struct task *t); +void print_filter_helps(bool detailed); +void print_filter_list(void); +int filter_setup(const char *fa, void **conf, struct lls_parse_result **lprp); +#define FILTER_CMD(_num) (lls_cmd(_num, filter_cmd_suite)) +#define FILTER_CMD_OPT(_cmd, _opt) (lls_opt( \ + LSG_FILTER_CMD_ ## _cmd ## _OPT_ ## _opt, \ + FILTER_CMD(LSG_FILTER_CMD_CMD_ ## _cmd))) +#define FILTER_CMD_OPT_RESULT(_cmd, _opt, _lpr) \ + (lls_opt_result(LSG_FILTER_CMD_ ## _cmd ## _OPT_ ## _opt, _lpr)) +#define FILTER_CMD_OPT_GIVEN(_cmd, _opt, _lpr) \ + (lls_opt_given(FILTER_CMD_OPT_RESULT(_cmd, _opt, _lpr))) +#define FILTER_CMD_OPT_UINT32_VAL(_cmd, _opt, _lpr) \ + (lls_uint32_val(0, FILTER_CMD_OPT_RESULT(_cmd, _opt, _lpr))) +#define FILTER_CMD_OPT_STRING_VAL(_cmd, _opt, _lpr) \ + (lls_string_val(0, FILTER_CMD_OPT_RESULT(_cmd, _opt, _lpr))) + +void generic_filter_pre_select(struct sched *s, void *context); int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels, char **result); @@ -134,9 +143,6 @@ static inline void write_int16_host_endian(char *buf, int val) #endif } -DECLARE_FILTER_INITS - -#define FOR_EACH_SUPPORTED_FILTER(j) for (j = 0; j < NUM_SUPPORTED_FILTERS; j++) - -/** The filter array, one structure for each supported filter. */ -extern struct filter filters[NUM_SUPPORTED_FILTERS]; +/** Make a filter pointer from the filter number. */ +const struct filter *filter_get(int filter_num); +const char *filter_name(int filter_num);