para_server: Don't link with stat.o.
[paraslash.git] / audiod.c
index e33f7383c83c8b088c5d17ee01c41ea83088f262..2b6f1e69637d1b851926d25b277c90c6d6f5df9a 100644 (file)
--- a/audiod.c
+++ b/audiod.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -7,12 +7,16 @@
 /** \file audiod.c the paraslash's audio daemon */
 #include <sys/types.h>
 #include <dirent.h>
+#include <signal.h>
+#include <openssl/rc4.h>
 
 #include "para.h"
 #include "error.h"
+#include "crypt.h"
 #include "audiod.cmdline.h"
 #include "list.h"
 #include "sched.h"
+#include "ggo.h"
 #include "recv.h"
 #include "filter.h"
 #include "grab_client.cmdline.h"
@@ -41,14 +45,14 @@ struct audio_format_info {
        void *receiver_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_filters;
-       /** pointer to the array of filters to be activated */
-       struct filter **filters;
-       /** pointer to the array of filter configurations */
+       /** Array of filter numbers to be activated. */
+       unsigned *filter_nums;
+       /** Pointer to the array of filter configurations. */
        void **filter_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_writers;
-       /** pointer to the array of writers to be activated */
-       struct writer **writers;
+       /** Array of writer numbers to be activated. */
+       int *writer_nums;
        /** pointer to the array of writer configurations */
        void **writer_conf;
        /** do not start receiver/filters/writer before this time */
@@ -64,6 +68,50 @@ struct audio_format_info {
  * */
 struct slot_info slot[MAX_STREAM_SLOTS];
 
+/** The vss status flags audiod is interested in. */
+enum vss_status_flags {
+       /** Whether the 'N' flag is set. */
+       VSS_STATUS_FLAG_NEXT = 1,
+       /** The 'P' flag is set. */
+       VSS_STATUS_FLAG_PLAYING = 2,
+};
+
+/**
+ * The task for obtaining para_server's status (para_client stat).
+ *
+ * \sa struct task, struct sched.
+ */
+struct status_task {
+       /** The associated task structure of audiod. */
+       struct task task;
+       /** Client data associated with the stat task. */
+       struct client_task *ct;
+       /** Do not restart client command until this time. */
+       struct timeval restart_barrier;
+       /** Last time we received status data from para_server. */
+       struct timeval last_status_read;
+       /** The offset value announced by para_server. */
+       int offset_seconds;
+       /** The length of the current audio file as announced by para_server. */
+       int length_seconds;
+       /** The start of the current stream from the view of para_server. */
+       struct timeval server_stream_start;
+       /** The average time deviation between para_server and para_audiod. */
+       struct timeval sa_time_diff;
+       /** Whether client time is ahead of server time. */
+       int sa_time_diff_sign;
+       /** The 'P' and the 'N' flags as announced by para_server. */
+       enum vss_status_flags vss_status;
+       /** Number of times the clock difference is to be checked. */
+       unsigned clock_diff_count;
+       /** When to start the next check for clock difference. */
+       struct timeval clock_diff_barrier;
+       /** Number of the audio format as announced by para_server. */
+       int current_audio_format_num;
+};
+
+/** The array of status items sent by para_server. */
+char *stat_item_values[NUM_STAT_ITEMS] = {NULL};
 
 /**
  * the current mode of operation of which can be changed by the on/off/cycle
@@ -78,7 +126,6 @@ int audiod_status = AUDIOD_ON;
 struct audiod_args_info conf;
 
 static char *socket_name;
-static FILE *logfile;
 static struct audio_format_info afi[NUM_AUDIO_FORMATS];
 
 static struct signal_task signal_task_struct, *sig_task = &signal_task_struct;
@@ -90,7 +137,7 @@ static struct status_task status_task_struct;
  *
  * \sa struct status_task
  */
-struct status_task *stat_task = &status_task_struct;
+static struct status_task *stat_task = &status_task_struct;
 static struct timeval initial_delay_barrier;
 
 /**
@@ -127,49 +174,110 @@ int get_audio_format_num(char *name)
        return -E_UNSUPPORTED_AUDIO_FORMAT;
 }
 
-/**
- * the log function of para_audiod
- *
- * \param ll loglevel
- * \param fmt the format string
- */
-void para_log(int ll, const char* fmt,...)
+char *get_time_string(int slot_num)
 {
-       va_list argp;
-       FILE *outfd;
-       struct tm *tm;
-       time_t t1;
-       char str[MAXLINE] = "";
-       static char *hostname;
-
-       if (ll < conf.loglevel_arg)
-               return;
-       if (!logfile && conf.daemon_given)
-               return;
-       if (!hostname)
-               hostname = para_hostname();
-       outfd = logfile? logfile : stderr;
-       time(&t1);
-       tm = localtime(&t1);
-       strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
-       fprintf(outfd, "%s %s ", str, hostname);
-       if (conf.loglevel_arg <= INFO)
-               fprintf(outfd, "%i ", ll);
-       va_start(argp, fmt);
-       vfprintf(outfd, fmt, argp);
-       va_end(argp);
+       int ret, seconds = 0, length;
+       struct timeval *tmp, sum, sss, /* server stream start */
+               wtime, /* now - writer start */
+               rskip; /* receiver start - sss */
+       struct slot_info *s = slot_num < 0? NULL : &slot[slot_num];
+
+       if (audiod_status == AUDIOD_OFF)
+               goto empty;
+       if (!(stat_task->vss_status & VSS_STATUS_FLAG_PLAYING)) {
+               if (stat_task->length_seconds) /* paused */
+                       return NULL;
+               goto empty; /* stopped */
+       }
+       if (audiod_status == AUDIOD_ON && !s)
+               goto empty;
+       /* valid status items and playing */
+       if (s) { /* writer active in this slot */
+               length = s->seconds_total;
+               tmp = &s->server_stream_start;
+       } else { /* standby mode, rely on status items */
+               length = stat_task->length_seconds;
+               tmp = &stat_task->server_stream_start;
+       }
+       if (stat_task->sa_time_diff_sign > 0)
+               tv_diff(tmp, &stat_task->sa_time_diff, &sss);
+       else
+               tv_add(tmp, &stat_task->sa_time_diff, &sss);
+       if (!s) {
+               struct timeval diff;
+               tv_diff(now, &sss, &diff);
+               seconds = diff.tv_sec + stat_task->offset_seconds;
+               goto out;
+       }
+       tv_diff(now, &s->wstime, &wtime);
+       seconds = s->offset_seconds;
+       ret = tv_diff(&s->rstime, &sss, &rskip);
+       if (ret > 0) { /* audiod was started in the middle of the stream */
+               tv_add(&wtime, &rskip, &sum);
+               seconds += sum.tv_sec;
+       } else
+               seconds += wtime.tv_sec;
+out:
+       seconds = PARA_MIN(seconds, length);
+       seconds = PARA_MAX(seconds, 0);
+       return make_message(
+               "%s%d:%02d [%d:%02d] (%d%%/%d:%02d)",
+               s? "" : "~",
+               seconds / 60,
+               seconds % 60,
+               (length - seconds) / 60,
+               (length - seconds) % 60,
+               length? (seconds * 100 + length / 2) / length : 0,
+               length / 60,
+               length % 60
+       );
+empty:
+       return para_strdup(NULL);
+}
+
+static int want_colors(void)
+{
+       if (conf.color_arg == color_arg_no)
+               return 0;
+       if (conf.color_arg == color_arg_yes)
+               return 1;
+       if (conf.logfile_given)
+               return 0;
+       return isatty(STDERR_FILENO);
 }
 
-static char *configfile_exists(void)
+static void parse_config_or_die(void)
 {
-       char *home = para_homedir();
-       char *config_file = make_message("%s/.paraslash/audiod.conf",
-               home);
-       free(home);
-       if (file_exists(config_file))
-               return config_file;
+       int ret;
+       char *config_file;
+       struct audiod_cmdline_parser_params params = {
+               .override = 0,
+               .initialize = 0,
+               .check_required = 1,
+               .check_ambiguity = 0,
+               .print_errors = 1
+       };
+
+       if (conf.config_file_given)
+               config_file = para_strdup(conf.config_file_arg);
+       else {
+               char *home = para_homedir();
+               config_file = make_message("%s/.paraslash/audiod.conf", home);
+               free(home);
+       }
+       ret = file_exists(config_file);
+       if (conf.config_file_given && !ret) {
+               PARA_EMERG_LOG("can not read config file %s\n", config_file);
+               goto err;
+       }
+       if (ret)
+               audiod_cmdline_parser_config_file(config_file, &conf, &params);
+       free(config_file);
+       daemon_set_loglevel(conf.loglevel_arg);
+       return;
+err:
        free(config_file);
-       return NULL;
+       exit(EXIT_FAILURE);
 }
 
 static void setup_signal_handling(void)
@@ -179,7 +287,7 @@ static void setup_signal_handling(void)
        para_install_sighandler(SIGINT);
        para_install_sighandler(SIGTERM);
        para_install_sighandler(SIGHUP);
-       signal(SIGPIPE, SIG_IGN);
+       para_sigaction(SIGPIPE, SIG_IGN);
 }
 
 static void clear_slot(int slot_num)
@@ -212,20 +320,17 @@ static void kill_all_decoders(int error)
 
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
-               if (s->wng && !s->wng->task.error) {
-                       PARA_INFO_LOG("unregistering writer node group in slot %d\n",
+               if (s->wng && s->wng->task.error >= 0) {
+                       PARA_INFO_LOG("deactivating wng in slot %d\n",
                                i);
-                       wng_unregister(s->wng);
                        s->wng->task.error = error;
                }
-               if (s->fc && !s->fc->task.error) {
-                       PARA_INFO_LOG("unregistering filter chain in slot %d\n", i);
-                       unregister_task(&s->fc->task);
+               if (s->fc && s->fc->task.error >= 0) {
+                       PARA_INFO_LOG("deactivatimg filter chain in slot %d\n", i);
                        s->fc->task.error = error;
                }
-               if (s->receiver_node && !s->receiver_node->task.error) {
-                       PARA_INFO_LOG("unregistering receiver_node in slot %d\n", i);
-                       unregister_task(&s->receiver_node->task);
+               if (s->receiver_node && s->receiver_node->task.error >= 0) {
+                       PARA_INFO_LOG("deactivating receiver_node in slot %d\n", i);
                        s->receiver_node->task.error = error;
                }
        }
@@ -268,6 +373,7 @@ static void open_filters(int slot_num)
 {
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];
+       struct filter_node *fn;
        int nf = a->num_filters;
        int i;
 
@@ -276,27 +382,28 @@ static void open_filters(int slot_num)
                return;
        PARA_INFO_LOG("opening %s filters\n", audio_formats[s->format]);
        s->fc = para_calloc(sizeof(struct filter_chain));
-       INIT_LIST_HEAD(&s->fc->filters);
-       s->fc->inbuf = s->receiver_node->buf;
+       s->fc->filter_nodes = para_malloc(nf * sizeof(struct filter_node));
+       s->fc->inbufp = &s->receiver_node->buf;
        s->fc->in_loaded = &s->receiver_node->loaded;
        s->fc->input_error = &s->receiver_node->task.error;
        s->fc->task.pre_select = filter_pre_select;
+       s->fc->task.post_select = NULL;
        s->fc->task.error = 0;
+       s->fc->num_filters = nf;
 
        s->receiver_node->output_error = &s->fc->task.error;
        sprintf(s->fc->task.status, "filter chain");
-       for (i = 0; i < nf; i++) {
-               struct filter_node *fn = para_calloc(sizeof(struct filter_node));
+       FOR_EACH_FILTER_NODE(fn, s->fc, i) {
+               struct filter *f = filters + a->filter_nums[i];
+               fn->filter_num = a->filter_nums[i];
                fn->conf = a->filter_conf[i];
                fn->fc = s->fc;
-               fn->filter = a->filters[i];
+               fn->loaded = 0;
                INIT_LIST_HEAD(&fn->callbacks);
-               list_add_tail(&fn->node, &s->fc->filters);
-               fn->filter->open(fn);
+               f->open(fn);
                PARA_NOTICE_LOG("%s filter %d/%d (%s) started in slot %d\n",
-                       audio_formats[s->format], i + 1,  nf,
-                       fn->filter->name, slot_num);
-               s->fc->outbuf = fn->buf;
+                       audio_formats[s->format], i,  nf, f->name, slot_num);
+               s->fc->outbufp = &fn->buf;
                s->fc->out_loaded = &fn->loaded;
        }
        register_task(&s->fc->task);
@@ -314,7 +421,7 @@ static void open_writers(int slot_num)
        else
                s->wng = wng_new(a->num_writers);
        if (s->fc) {
-               s->wng->buf = s->fc->outbuf;
+               s->wng->bufp = s->fc->outbufp;
                s->wng->loaded = s->fc->out_loaded;
                s->wng->input_error = &s->fc->task.error;
                s->wng->channels = &s->fc->channels;
@@ -322,52 +429,32 @@ static void open_writers(int slot_num)
                s->fc->output_error = &s->wng->task.error;
                PARA_INFO_LOG("samplerate: %d\n", *s->wng->samplerate);
        } else {
-               s->wng->buf = s->receiver_node->buf;
+               s->wng->bufp = &s->receiver_node->buf;
                s->wng->loaded = &s->receiver_node->loaded;
                s->wng->input_error = &s->receiver_node->task.error;
        }
        for (i = 0; i < a->num_writers; i++) {
                s->wng->writer_nodes[i].conf = a->writer_conf[i];
-               s->wng->writer_nodes[i].writer = a->writers[i];
+               s->wng->writer_nodes[i].writer_num = a->writer_nums[i];
        }
        ret = wng_open(s->wng);
-       if (ret < 0) {
-               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+       if (ret < 0)
                return;
-       }
        s->wstime = *now;
-       activate_inactive_grab_clients(slot_num, s->format, &s->fc->filters);
+       s->server_stream_start = stat_task->server_stream_start.tv_sec?
+               stat_task->server_stream_start : *now;
+       s->offset_seconds = stat_task->offset_seconds;
+       s->seconds_total = stat_task->length_seconds;
+       activate_inactive_grab_clients(slot_num, s->format, s->fc);
 }
 
-#if 0
-static void rn_event_handler(struct task *t)
-{
-       struct receiver_node *rn = t->private_data;
-       int i;
-
-       PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
-       unregister_task(t);
-       rn->error = t->ret;
-       /* set restart barrier */
-       FOR_EACH_SLOT(i) {
-               struct timeval restart_delay = {0, 10 * 1000};
-               if (slot[i].receiver_node != rn)
-                       continue;
-               if (rn->error != -E_RECV_EOF)
-                       /* don't reconnect immediately on errors */
-                       restart_delay.tv_sec = 5;
-               tv_add(now, &restart_delay, &afi[slot[i].format].restart_barrier);
-       }
-}
-#endif
-
 static int open_receiver(int format)
 {
        struct audio_format_info *a = &afi[format];
        struct slot_info *s;
        int ret, slot_num;
        struct receiver_node *rn;
-       const struct timeval restart_delay = {1, 0};
+       const struct timeval restart_delay = {2, 0};
 
        ret = get_empty_slot();
        if (ret < 0)
@@ -389,42 +476,65 @@ static int open_receiver(int format)
                audio_formats[s->format], a->receiver->name, slot_num);
        rn->task.pre_select = a->receiver->pre_select;
        rn->task.post_select = a->receiver->post_select;
+       s->rstime = *now;
        sprintf(rn->task.status, "%s receiver node", rn->receiver->name);
        register_task(&rn->task);
-       return 1;
+       ret = 1;
 err:
-       PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+       if (ret < 0)
+               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
        tv_add(now, &restart_delay, &afi[format].restart_barrier);
        return ret;
 }
 
+/* return: 0: Not running, 1: Running, -1: Running but eof (or error) */
 static int receiver_running(int format)
 {
-       int i;
+       int i, ret = 0;
 
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
-               if (s->format == format && s->receiver_node
-                               && s->receiver_node->task.error >= 0)
+               if (s->format != format)
+                       continue;
+               if (!s->receiver_node)
+                       continue;
+               if (s->receiver_node->task.error >= 0)
                        return 1;
+               ret = -1;
        }
-       return 0;
+       return ret;
 }
 
-static int open_current_receiver(struct sched *s)
+static void open_current_receiver(struct sched *s)
 {
        struct timeval diff;
-       int cafn = stat_task->current_audio_format_num;
+       int ret, cafn = stat_task->current_audio_format_num;
 
        if (cafn < 0 || !stat_task->ct)
-               return 0;
-       if (receiver_running(cafn))
-               return 0;
+               return;
+       /* Do nothing if the 'N' flag is set or the 'P' flag is unset */
+       if (stat_task->vss_status != VSS_STATUS_FLAG_PLAYING)
+               return;
+       ret = receiver_running(cafn);
+       if (ret > 0) /* already running and not eof */
+               return;
+       if (ret < 0) { /* eof */
+               /*
+                * para_server uses a zero start time during the announcement
+                * period, i.e. before it sends the first chunk. Wait until
+                * this period begins to avoid restarting the receiver that
+                * belongs to the file just completed.
+                */
+               if (stat_task->server_stream_start.tv_sec)
+                       return;
+       }
        if (tv_diff(now, &afi[cafn].restart_barrier, &diff) < 0) {
+               /* avoid busy loop */
                s->timeout = diff;
-               return 0;
+               return;
        }
-       return open_receiver(cafn) < 0? 0 : 1;
+       /* start a new receiver */
+       open_receiver(cafn);
 }
 
 static unsigned compute_time_diff(const struct timeval *status_time)
@@ -469,42 +579,31 @@ out:
        return count;
 }
 
-static int check_stat_line(char *line, __a_unused void *data)
+static int update_item(int itemnum, char *buf)
 {
-       int itemnum;
-       size_t ilen = 0;
        long unsigned sec, usec;
-       char *tmp;
 
-       //PARA_INFO_LOG("line: %s\n", line);
-       if (!line)
-               return 1;
-       itemnum = stat_line_valid(line);
-       if (itemnum < 0) {
-               PARA_WARNING_LOG("invalid status line: %s\n", line);
-               return 1;
-       }
        if (stat_task->clock_diff_count && itemnum != SI_CURRENT_TIME)
                return 1;
-       tmp = make_message("%s\n", line);
-       stat_client_write(tmp, itemnum);
-       free(tmp);
-       free(stat_task->stat_item_values[itemnum]);
-       stat_task->stat_item_values[itemnum] = para_strdup(line);
-       ilen = strlen(status_item_list[itemnum]);
+       free(stat_item_values[itemnum]);
+       stat_item_values[itemnum] = para_strdup(buf);
+       stat_client_write_item(itemnum);
        switch (itemnum) {
-       case SI_STATUS:
-               stat_task->playing = strstr(line, "playing")? 1 : 0;
-               PARA_INFO_LOG("stat task playing: %d\n", stat_task->playing);
+       case SI_STATUS_FLAGS:
+               stat_task->vss_status = 0;
+               if (strchr(buf, 'N'))
+                       stat_task->vss_status |= VSS_STATUS_FLAG_NEXT;
+               if (strchr(buf, 'P'))
+                       stat_task->vss_status |= VSS_STATUS_FLAG_PLAYING;
                break;
        case SI_OFFSET:
-               stat_task->offset_seconds = atoi(line + ilen + 1);
+               stat_task->offset_seconds = atoi(buf);
                break;
        case SI_SECONDS_TOTAL:
-               stat_task->length_seconds = atoi(line + ilen + 1);
+               stat_task->length_seconds = atoi(buf);
                break;
        case SI_STREAM_START:
-               if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
+               if (sscanf(buf, "%lu.%lu", &sec, &usec) == 2) {
                        struct timeval a_start, delay;
                        delay.tv_sec = conf.stream_delay_arg / 1000;
                        delay.tv_usec = (conf.stream_delay_arg % 1000) * 1000;
@@ -522,110 +621,18 @@ static int check_stat_line(char *line, __a_unused void *data)
                }
                break;
        case SI_CURRENT_TIME:
-               if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
+               if (sscanf(buf, "%lu.%lu", &sec, &usec) == 2) {
                        struct timeval tv = {sec, usec};
                        compute_time_diff(&tv);
                }
-               if (stat_task->clock_diff_count)
-                       stat_task->clock_diff_count--;
                break;
        case SI_FORMAT:
-               stat_task->current_audio_format_num = get_audio_format_num(
-                       line + ilen + 1);
+               stat_task->current_audio_format_num
+                       = get_audio_format_num(buf);
        }
        return 1;
 }
 
-static void try_to_close_slot(int slot_num)
-{
-       struct slot_info *s = &slot[slot_num];
-
-       if (s->format < 0)
-               return;
-       if (s->receiver_node && s->receiver_node->task.error >= 0)
-               return;
-       if (s->fc && s->fc->task.error >= 0)
-               return;
-       if (s->wng && s->wng->task.error >= 0)
-               return;
-       PARA_INFO_LOG("closing slot %d\n", slot_num);
-       wng_close(s->wng);
-       close_filters(s->fc);
-       free(s->fc);
-       close_receiver(slot_num);
-       clear_slot(slot_num);
-}
-
-/*
- * Check if any receivers/filters/writers need to be started and do so if
- * necessary.  Since the pre_select function didn't have a chance yet to put
- * file descriptors into the fd sets given by s, make the upcoming select()
- * return immediately to avoid a long timeout in case we started something.
- */
-static void audiod_pre_select(struct sched *s, __a_unused struct task *t)
-{
-       int i;
-       struct timeval min_delay = {0, 1};
-
-       if (audiod_status != AUDIOD_ON || !stat_task->playing)
-               return kill_all_decoders(-E_NOT_PLAYING);
-       if (open_current_receiver(s))
-               s->timeout = min_delay;
-       FOR_EACH_SLOT(i) {
-               struct slot_info *sl = &slot[i];
-               struct audio_format_info *a;
-               struct timeval diff;
-
-               if (sl->format < 0)
-                       continue;
-               a = &afi[sl->format];
-               if (!sl->receiver_node)
-                       continue;
-               if ((!a->num_filters || sl->fc) && sl->wng)
-                       continue; /* everything already started */
-               if (!a->num_filters) {
-                       if (sl->receiver_node->loaded && !sl->wng) {
-                               open_writers(i);
-                               s->timeout = min_delay;
-                       }
-                       continue;
-               }
-               if (sl->receiver_node->loaded && !sl->fc) {
-                       open_filters(i);
-                       s->timeout = min_delay;
-                       continue;
-               }
-               if (sl->wng || !sl->fc || !*sl->fc->out_loaded)
-                       continue;
-               if (tv_diff(now, &initial_delay_barrier, &diff) > 0) {
-                       open_writers(i);
-                       s->timeout = min_delay;
-                       continue;
-               }
-               PARA_INFO_LOG("initial delay: %lu ms left\n", tv2ms(&diff));
-               if (tv_diff(&s->timeout, &diff, NULL) > 0) {
-                       s->timeout = diff;
-               }
-       }
-}
-
-static void audiod_post_select(__a_unused struct sched *s,
-       __a_unused struct task *t)
-{
-       int i;
-
-       FOR_EACH_SLOT(i)
-               try_to_close_slot(i);
-}
-
-static void init_audiod_task(struct task *t)
-{
-       t->pre_select = audiod_pre_select;
-       t->post_select = audiod_post_select;
-       t->error = 0;
-       sprintf(t->status, "audiod task");
-}
-
 static int parse_stream_command(const char *txt, char **cmd)
 {
        char *p = strchr(txt, ':');
@@ -651,26 +658,25 @@ static int add_filter(int format, char *cmdline)
        filter_num = check_filter_arg(cmdline, &a->filter_conf[nf]);
        if (filter_num < 0)
                return filter_num;
-       a->filters[nf] = &filters[filter_num];
+       a->filter_nums[nf] = filter_num;
        a->num_filters++;
-       PARA_INFO_LOG("%s filter %d: %s\n", audio_formats[format], nf + 1,
-               a->filters[nf]->name);
+       PARA_INFO_LOG("%s filter %d: %s\n", audio_formats[format], nf,
+               filters[filter_num].name);
        return filter_num;
 }
 
-static int init_writers(void)
+static int parse_writer_args(void)
 {
        int i, ret, nw;
        char *cmd;
        struct audio_format_info *a;
 
-       init_supported_writers();
-       nw = PARA_MAX(1, conf.writer_given);
+       nw = PARA_MAX(1U, conf.writer_given);
        PARA_INFO_LOG("maximal number of writers: %d\n", nw);
        FOR_EACH_AUDIO_FORMAT(i) {
                a = &afi[i];
                a->writer_conf = para_malloc(nw * sizeof(void *));
-               a->writers = para_malloc(nw * sizeof(struct writer *));
+               a->writer_nums = para_malloc(nw * sizeof(int));
                a->num_writers = 0;
        }
        for (i = 0; i < conf.writer_given; i++) {
@@ -686,7 +692,7 @@ static int init_writers(void)
                        ret = writer_num;
                        goto out;
                }
-               a->writers[nw] = &writers[writer_num];
+               a->writer_nums[nw] = writer_num;
                a->writer_conf[nw] = wconf;
                PARA_INFO_LOG("%s writer #%d: %s\n", audio_formats[ret],
                        nw, writer_names[writer_num]);
@@ -697,16 +703,12 @@ out:
        return ret;
 }
 
-static int init_receivers(void)
+static int parse_receiver_args(void)
 {
        int i, ret, receiver_num;
        char *cmd = NULL;
        struct audio_format_info *a;
 
-       for (i = 0; receivers[i].name; i++) {
-               PARA_INFO_LOG("initializing %s receiver\n", receivers[i].name);
-               receivers[i].init(&receivers[i]);
-       }
        for (i = conf.receiver_given - 1; i >= 0; i--) {
                char *arg = conf.receiver_arg[i];
                char *recv_arg = strchr(arg, ':');
@@ -777,16 +779,15 @@ out:
        return ret;
 }
 
-static int init_filters(void)
+static int parse_filter_args(void)
 {
        int i, ret, nf;
 
-       filter_init(filters);
-       nf = PARA_MAX(1,  conf.filter_given);
+       nf = PARA_MAX(1U, conf.filter_given);
        PARA_INFO_LOG("maximal number of filters: %d\n", nf);
        FOR_EACH_AUDIO_FORMAT(i) {
                afi[i].filter_conf = para_malloc(nf * sizeof(void *));
-               afi[i].filters = para_malloc(nf * sizeof(struct filter *));
+               afi[i].filter_nums = para_malloc(nf * sizeof(unsigned));
        }
        if (!conf.no_default_filters_given)
                return init_default_filters();
@@ -810,17 +811,17 @@ out:
        return ret;
 }
 
-static int init_stream_io(void)
+static int parse_stream_args(void)
 {
        int ret;
 
-       ret = init_writers();
+       ret = parse_receiver_args();
        if (ret < 0)
                return ret;
-       ret = init_receivers();
+       ret = parse_filter_args();
        if (ret < 0)
                return ret;
-       ret = init_filters();
+       ret = parse_writer_args();
        if (ret < 0)
                return ret;
        return 1;
@@ -870,13 +871,12 @@ static void signal_pre_select(struct sched *s, struct task *t)
 static void signal_post_select(struct sched *s, struct task *t)
 {
        struct signal_task *st = container_of(t, struct signal_task, task);
-       int signum;
 
        if (!FD_ISSET(st->fd, &s->rfds))
                return;
 
-       signum = para_next_signal();
-       switch (signum) {
+       st->signum = para_next_signal();
+       switch (st->signum) {
        case SIGINT:
        case SIGTERM:
        case SIGHUP:
@@ -922,30 +922,15 @@ static void init_command_task(struct command_task *ct)
 
 static void close_stat_pipe(void)
 {
-       int i;
-
        if (!stat_task->ct)
                return;
        client_close(stat_task->ct);
        stat_task->ct = NULL;
-       FOR_EACH_STATUS_ITEM(i) {
-               free(stat_task->stat_item_values[i]);
-               stat_task->stat_item_values[i] = NULL;
-       }
-       dump_empty_status();
+       clear_and_dump_items();
        stat_task->length_seconds = 0;
        stat_task->offset_seconds = 0;
+       stat_task->vss_status = 0;
        audiod_status_dump();
-       stat_task->playing = 0;
-       stat_task->stat_item_values[SI_BASENAME] = make_message(
-               "%s: no connection to para_server\n",
-               status_item_list[SI_BASENAME]);
-       stat_client_write(stat_task->stat_item_values[SI_BASENAME],
-               SI_BASENAME);
-       if (stat_task->clock_diff_count) {
-               stat_task->clock_diff_barrier.tv_sec = now->tv_sec + 1;
-               stat_task->clock_diff_barrier.tv_usec = now->tv_usec;
-       }
 }
 
 /**
@@ -970,76 +955,156 @@ void __noreturn clean_exit(int status, const char *msg)
 }
 
 /* avoid busy loop if server is down */
-static void set_stat_task_restart_barrier(void)
+static void set_stat_task_restart_barrier(unsigned seconds)
 {
-       struct timeval delay = {5, 0};
+       struct timeval delay = {seconds, 0};
        tv_add(now, &delay, &stat_task->restart_barrier);
 }
 
-/* restart the client task if necessary */
-static void status_pre_select(struct sched *s, struct task *t)
+static void try_to_close_slot(int slot_num)
 {
-       struct status_task *st = container_of(t, struct status_task, task);
-       int ret;
+       struct slot_info *s = &slot[slot_num];
 
-       if (st->ct || audiod_status == AUDIOD_OFF) /* no need to restart */
+       if (s->format < 0)
                return;
-       if (!st->clock_diff_count && tv_diff(now, &st->restart_barrier, NULL)
-                       < 0)
+       if (s->receiver_node && s->receiver_node->task.error != -E_TASK_UNREGISTERED)
                return;
-       if (st->clock_diff_count) { /* get status only one time */
-               char *argv[] = {"audiod", "stat", "1", NULL};
-               int argc = 3;
-               if (tv_diff(now, &st->clock_diff_barrier, NULL) < 0)
-                       return;
-               PARA_INFO_LOG("clock diff count: %d\n", st->clock_diff_count);
-               ret = client_open(argc, argv, &st->ct);
+       if (s->fc && s->fc->task.error != -E_TASK_UNREGISTERED)
+               return;
+       if (s->wng && s->wng->task.error != -E_TASK_UNREGISTERED)
+               return;
+       PARA_INFO_LOG("closing slot %d\n", slot_num);
+       wng_close(s->wng);
+       close_filters(s->fc);
+       free(s->fc);
+       close_receiver(slot_num);
+       clear_slot(slot_num);
+}
 
-       } else {
-               char *argv[] = {"audiod", "stat", NULL};
-               int argc = 2;
-               ret = client_open(argc, argv, &st->ct);
+/*
+ * Check if any receivers/filters/writers need to be started and do so if
+ * necessary.
+ */
+static void start_stop_decoders(struct sched *s)
+{
+       int i;
+
+       FOR_EACH_SLOT(i)
+               try_to_close_slot(i);
+       if (audiod_status != AUDIOD_ON ||
+                       !(stat_task->vss_status & VSS_STATUS_FLAG_PLAYING))
+               return kill_all_decoders(-E_NOT_PLAYING);
+       open_current_receiver(s);
+       FOR_EACH_SLOT(i) {
+               struct slot_info *sl = &slot[i];
+               struct audio_format_info *a;
+               struct timeval diff;
+
+               if (sl->format < 0)
+                       continue;
+               a = &afi[sl->format];
+               if (!sl->receiver_node)
+                       continue;
+               if ((!a->num_filters || sl->fc) && sl->wng)
+                       continue; /* everything already started */
+               if (!a->num_filters) {
+                       if (sl->receiver_node->loaded && !sl->wng) {
+                               open_writers(i);
+                       }
+                       continue;
+               }
+               if (sl->receiver_node->loaded && !sl->fc) {
+                       open_filters(i);
+                       continue;
+               }
+               if (sl->wng || !sl->fc || !*sl->fc->out_loaded)
+                       continue;
+               if (tv_diff(now, &initial_delay_barrier, &diff) > 0) {
+                       open_writers(i);
+                       continue;
+               }
+               PARA_INFO_LOG("initial delay: %lu ms left\n", tv2ms(&diff));
+               if (tv_diff(&s->timeout, &diff, NULL) > 0) {
+                       s->timeout = diff;
+               }
        }
-       set_stat_task_restart_barrier();
-       if (ret < 0)
-               return;
-       s->timeout.tv_sec = 0;
-       s->timeout.tv_usec = 1;
 }
 
-static void status_post_select(__a_unused struct sched *s, struct task *t)
+
+/* restart the client task if necessary */
+static void status_pre_select(struct sched *s, struct task *t)
 {
        struct status_task *st = container_of(t, struct status_task, task);
-       unsigned bytes_left;
 
-       if (!st->ct || st->ct->status != CL_RECEIVING)
-               return;
-       if (audiod_status == AUDIOD_OFF || st->ct->task.error < 0) {
-               if (st->ct->task.error >= 0)
-                       unregister_task(&st->ct->task);
-               if (audiod_status == AUDIOD_OFF)
-                       st->clock_diff_count = conf.clock_diff_count_arg;
+       if (audiod_status == AUDIOD_OFF) {
+               if (!st->ct)
+                       goto out;
+               if (st->ct->task.error >= 0) {
+                       st->ct->task.error = -E_AUDIOD_OFF;
+                       goto out;
+               }
+               if (st->ct->task.error != -E_TASK_UNREGISTERED)
+                       goto out;
                close_stat_pipe();
-               return;
+               st->clock_diff_count = conf.clock_diff_count_arg;
+               goto out;
        }
-       bytes_left = for_each_line(st->ct->buf, st->ct->loaded,
-               &check_stat_line, NULL);
-       if (st->ct->loaded != bytes_left) {
-               st->last_status_read = *now;
-               st->ct->loaded = bytes_left;
-       } else {
-               struct timeval diff;
-               tv_diff(now, &st->last_status_read, &diff);
-               if (diff.tv_sec > 61)
+       if (st->ct) {
+               int ret;
+               if (st->ct->task.error < 0) {
+                       if (st->ct->task.error != -E_TASK_UNREGISTERED)
+                               goto out;
                        close_stat_pipe();
+                       goto out;
+               }
+               if (st->ct->status != CL_RECEIVING)
+                       goto out;
+               ret = for_each_stat_item(st->ct->buf, st->ct->loaded,
+                       update_item);
+               if (ret < 0) {
+                       st->ct->task.error = ret;
+                       goto out;
+               }
+               if (st->ct->loaded != ret) {
+                       st->last_status_read = *now;
+                       st->ct->loaded = ret;
+               } else {
+                       struct timeval diff;
+                       tv_diff(now, &st->last_status_read, &diff);
+                       if (diff.tv_sec > 61)
+                               st->ct->task.error = -E_STATUS_TIMEOUT;
+               }
+               goto out;
+       }
+       if (tv_diff(now, &st->restart_barrier, NULL) < 0)
+               goto out;
+       if (st->clock_diff_count) { /* get status only one time */
+               char *argv[] = {"audiod", "--", "stat", "-p", "1", NULL};
+               int argc = 5;
+               PARA_INFO_LOG("clock diff count: %d\n", st->clock_diff_count);
+               st->clock_diff_count--;
+               client_open(argc, argv, &st->ct, NULL);
+               set_stat_task_restart_barrier(2);
+
+       } else {
+               char *argv[] = {"audiod", "--", "stat", "-p", NULL};
+               int argc = 4;
+               client_open(argc, argv, &st->ct, NULL);
+               set_stat_task_restart_barrier(5);
        }
+       free(stat_item_values[SI_BASENAME]);
+       stat_item_values[SI_BASENAME] = para_strdup(
+               "no connection to para_server");
+       stat_client_write_item(SI_BASENAME);
+       st->last_status_read = *now;
+out:
+       start_stop_decoders(s);
 }
 
 static void init_status_task(struct status_task *st)
 {
        memset(st, 0, sizeof(struct status_task));
        st->task.pre_select = status_pre_select;
-       st->task.post_select = status_post_select;
        st->sa_time_diff_sign = 1;
        st->clock_diff_count = conf.clock_diff_count_arg;
        st->current_audio_format_num = -1;
@@ -1063,6 +1128,38 @@ static void set_initial_status(void)
                PARA_WARNING_LOG("invalid mode\n");
 }
 
+__noreturn static void print_help_and_die(void)
+{
+       int d = conf.detailed_help_given;
+       const char **p = d? audiod_args_info_detailed_help
+               : audiod_args_info_help;
+
+       printf_or_die("%s\n\n", AUDIOD_CMDLINE_PARSER_PACKAGE "-"
+               AUDIOD_CMDLINE_PARSER_VERSION);
+       printf_or_die("%s\n\n", audiod_args_info_usage);
+       for (; *p; p++)
+               printf_or_die("%s\n", *p);
+       print_receiver_helps(d);
+       print_filter_helps(d);
+       print_writer_helps(d);
+       exit(0);
+}
+
+static void init_colors_or_die(void)
+{
+       int ret, i;
+
+       if (!want_colors())
+               return;
+       daemon_set_default_log_colors();
+       daemon_set_flag(DF_COLOR_LOG);
+       for (i = 0; i < conf.log_color_given; i++) {
+               ret = daemon_set_log_color(conf.log_color_arg[i]);
+               if (ret < 0)
+                       exit(EXIT_FAILURE);
+       }
+}
+
 /**
  * the main function of para_audiod
  *
@@ -1075,39 +1172,43 @@ static void set_initial_status(void)
  * */
 int main(int argc, char *argv[])
 {
-       char *config_file;
        int ret, i;
-       struct sched s;
+       static struct sched s;
        struct command_task command_task_struct, *cmd_task = &command_task_struct;
-       struct task audiod_task_struct, *audiod_task = &audiod_task_struct;
+       struct audiod_cmdline_parser_params params = {
+               .override = 0,
+               .initialize = 1,
+               .check_required = 0,
+               .check_ambiguity = 0,
+               .print_errors = 1
+       };
 
        valid_fd_012();
-       audiod_cmdline_parser(argc, argv, &conf);
+       if (audiod_cmdline_parser_ext(argc, argv, &conf, &params))
+               exit(EXIT_FAILURE);
        HANDLE_VERSION_FLAG("audiod", conf);
-       para_drop_privileges(conf.user_arg, conf.group_arg);
-       config_file = configfile_exists();
-       if (config_file) {
-               struct audiod_cmdline_parser_params params = {
-                       .override = 0,
-                       .initialize = 0,
-                       .check_required = 0,
-                       .check_ambiguity = 0
-
-               };
-               if (audiod_cmdline_parser_config_file(config_file, &conf, &params)) {
-                       PARA_EMERG_LOG("parse error in config file\n");
-                       exit(EXIT_FAILURE);
-               }
-               free(config_file);
+       /* init receivers/filters/writers early to make help work */
+       recv_init();
+       filter_init();
+       writer_init();
+       if (conf.help_given || conf.detailed_help_given)
+               print_help_and_die();
+       drop_privileges_or_die(conf.user_arg, conf.group_arg);
+       parse_config_or_die();
+       init_colors_or_die();
+       daemon_set_flag(DF_LOG_TIME);
+       daemon_set_flag(DF_LOG_HOSTNAME);
+       daemon_set_flag(DF_LOG_LL);
+       if (conf.logfile_given) {
+               daemon_set_logfile(conf.logfile_arg);
+               daemon_open_log_or_die();
        }
-       if (conf.logfile_given)
-               logfile = open_log(conf.logfile_arg);
-       log_welcome("para_audiod", conf.loglevel_arg);
-       i = init_stream_io();
-       if (i < 0) {
-               PARA_EMERG_LOG("init stream io error: %s\n", para_strerror(-i));
+       ret = parse_stream_args();
+       if (ret < 0) {
+               PARA_EMERG_LOG("%s\n", para_strerror(-ret));
                exit(EXIT_FAILURE);
        }
+       log_welcome("para_audiod");
        server_uptime(UPTIME_SET);
        set_initial_status();
        FOR_EACH_SLOT(i)
@@ -1118,15 +1219,13 @@ int main(int argc, char *argv[])
 
        init_status_task(stat_task);
        init_command_task(cmd_task);
-       init_audiod_task(audiod_task);
 
        if (conf.daemon_given)
-               daemon_init();
+               daemonize();
 
        register_task(&sig_task->task);
        register_task(&cmd_task->task);
        register_task(&stat_task->task);
-       register_task(audiod_task);
        s.default_timeout.tv_sec = 0;
        s.default_timeout.tv_usec = 99 * 1000;
        ret = schedule(&s);