audiod: Avoid to report 100% time at startup.
[paraslash.git] / play.c
diff --git a/play.c b/play.c
index fc33f68b9e13ee4111ce7ae915e5ace1fb888235..55c9ec1bbb635946fe8ec92eadb52fa0accc8bf6 100644 (file)
--- a/play.c
+++ b/play.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2012 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -7,6 +7,8 @@
 /** \file play.c Paraslash's standalone player. */
 
 #include <regex.h>
+#include <fnmatch.h>
+#include <signal.h>
 
 #include "para.h"
 #include "list.h"
 #include "write_common.h"
 #include "fd.h"
 
-static struct play_args_info conf;
+/**
+ * Besides playback tasks which correspond to the receiver/filter/writer nodes,
+ * para_play creates two further tasks: The play task and the i9e task. It is
+ * important whether a function can be called in the context of para_play or
+ * i9e or both. As a rule, all command handlers are called only in i9e context via
+ * the line handler (input mode) or the key handler (command mode) below.
+ *
+ * Playlist handling is done exclusively in play context.
+ */
+
+/**
+ * Describes a request to change the state of para_play.
+ *
+ * There is only one variable of this type: \a rq of the global play task
+ * structure. Command handlers only set this variable and the post_select()
+ * function of the play task investigates its value during each iteration of
+ * the scheduler run and performs the actual work.
+ */
+enum state_change_request_type {
+       /** Everybody is happy. */
+       CRT_NONE,
+       /** Stream must be repositioned (com_jmp(), com_ff()). */
+       CRT_REPOS,
+       /** New file should be loaded (com_next()). */
+       CRT_FILE_CHANGE,
+       /** Someone wants us for dead (com_quit()). */
+       CRT_TERM_RQ
+};
+
+struct play_task {
+       struct task *task;
+       /* A bit array of invalid files (those will be skipped). */
+       bool *invalid;
+       /* The file which is currently open. */
+       unsigned current_file;
+       /* When to update the status again. */
+       struct timeval next_update;
+
+       /* Root of the buffer tree for command and status output. */
+       struct btr_node *btrn;
+
+       /* The decoding machinery.  */
+       struct receiver_node rn;
+       struct filter_node fn;
+       struct writer_node wn;
+
+       /* See comment to enum state_change_request_type above */
+       enum state_change_request_type rq;
+       /* only relevant if rq == CRT_FILE_CHANGE */
+       unsigned next_file;
+       /*
+               bg: read lines at prompt, fg: display status and wait
+               for keystroke.
+       */
+       bool background;
+
+       /* We have the *intention* to play. Set by com_play(). */
+       bool playing;
+
+       /* as returned by afh_recv->open() */
+       int audio_format_num;
+
+       /* retrieved via the btr exec mechanism */
+       long unsigned start_chunk;
+       long unsigned seconds;
+       long unsigned num_chunks;
+       char *afhi_txt;
+};
 
 /** Initialize the array of errors for para_play. */
 INIT_PLAY_ERRLISTS;
@@ -33,34 +102,55 @@ INIT_PLAY_ERRLISTS;
 /* Activate the afh receiver. */
 extern void afh_recv_init(struct receiver *r);
 #undef AFH_RECEIVER
+/** Initialization code for a receiver struct. */
 #define AFH_RECEIVER {.name = "afh", .init = afh_recv_init},
+/** This expands to the array of all receivers. */
 DEFINE_RECEIVER_ARRAY;
 
-/* FIXME: This is needed by the amp filter. */
-char *stat_item_values[NUM_STAT_ITEMS] = {NULL};
-
 static int loglevel = LL_WARNING;
+
+/** The log function which writes log messages to stderr. */
 INIT_STDERR_LOGGING(loglevel);
 
+char *stat_item_values[NUM_STAT_ITEMS] = {NULL};
+
+/** Iterate over all files in the playlist. */
+#define FOR_EACH_PLAYLIST_FILE(i) for (i = 0; i < conf.inputs_num; i++)
+static struct play_args_info conf;
+
+static struct sched sched = {.max_fileno = 0};
+static struct play_task play_task;
+static struct receiver *afh_recv;
+
+static void check_afh_receiver_or_die(void)
+{
+       int i;
+
+       FOR_EACH_RECEIVER(i) {
+               struct receiver *r = receivers + i;
+               if (strcmp(r->name, "afh"))
+                       continue;
+               afh_recv = r;
+               return;
+       }
+       PARA_EMERG_LOG("fatal: afh receiver not found\n");
+       exit(EXIT_FAILURE);
+}
+
 __noreturn static void print_help_and_die(void)
 {
-       int d = conf.detailed_help_given;
-       const char **p = d? play_args_info_detailed_help
-               : play_args_info_help;
-
-       printf_or_die("%s\n\n", PLAY_CMDLINE_PARSER_PACKAGE "-"
-               PLAY_CMDLINE_PARSER_VERSION);
-       printf_or_die("%s\n\n", play_args_info_usage);
-       for (; *p; p++)
-               printf_or_die("%s\n", *p);
-       print_filter_helps(d);
-       print_writer_helps(d);
+       struct ggo_help help = DEFINE_GGO_HELP(play);
+       unsigned flags = conf.detailed_help_given?
+               GPH_STANDARD_FLAGS_DETAILED : GPH_STANDARD_FLAGS;
+
+       ggo_print_help(&help, flags);
+       printf("supported audio formats: %s\n", AUDIO_FORMAT_HANDLERS);
        exit(0);
 }
 
 static void parse_config_or_die(int argc, char *argv[])
 {
-       int ret;
+       int i, ret;
        char *config_file;
        struct play_cmdline_parser_params params = {
                .override = 0,
@@ -70,12 +160,11 @@ static void parse_config_or_die(int argc, char *argv[])
                .print_errors = 1
        };
 
-       if (play_cmdline_parser_ext(argc, argv, &conf, &params))
-               exit(EXIT_FAILURE);
-       HANDLE_VERSION_FLAG("play", conf);
+       play_cmdline_parser_ext(argc, argv, &conf, &params);
+       loglevel = get_loglevel_by_name(conf.loglevel_arg);
+       version_handle_flag("play", conf.version_given);
        if (conf.help_given || conf.detailed_help_given)
                print_help_and_die();
-       loglevel = get_loglevel_by_name(conf.loglevel_arg);
        if (conf.config_file_given)
                config_file = para_strdup(conf.config_file_arg);
        else {
@@ -92,6 +181,14 @@ static void parse_config_or_die(int argc, char *argv[])
                params.initialize = 0;
                params.check_required = 1;
                play_cmdline_parser_config_file(config_file, &conf, &params);
+               loglevel = get_loglevel_by_name(conf.loglevel_arg);
+       }
+       for (i = 0; i < conf.key_map_given; i++) {
+               char *kma = conf.key_map_arg[i];
+               if (*kma && strchr(kma + 1, ':'))
+                       continue;
+               PARA_EMERG_LOG("invalid key map arg: %s\n", kma);
+               goto err;
        }
        free(config_file);
        return;
@@ -100,13 +197,1077 @@ err:
        exit(EXIT_FAILURE);
 }
 
+static char get_playback_state(struct play_task *pt)
+{
+       switch (pt->rq) {
+       case CRT_NONE: return pt->playing? 'P' : 'U';
+       case CRT_REPOS: return 'R';
+       case CRT_FILE_CHANGE: return 'F';
+       case CRT_TERM_RQ: return 'X';
+       }
+       assert(false);
+};
+
+static long unsigned get_play_time(struct play_task *pt)
+{
+       char state = get_playback_state(pt);
+       long unsigned result;
+
+       if (state != 'P' && state != 'U')
+               return 0;
+       if (pt->num_chunks == 0 || pt->seconds == 0)
+               return 0;
+       /* where the stream started (in seconds) */
+       result = pt->start_chunk * pt->seconds / pt->num_chunks;
+       if (pt->wn.btrn) { /* Add the uptime of the writer node */
+               struct timeval diff = {.tv_sec = 0}, wstime;
+               btr_get_node_start(pt->wn.btrn, &wstime);
+               if (wstime.tv_sec > 0)
+                       tv_diff(now, &wstime, &diff);
+               result += diff.tv_sec;
+       }
+       result = PARA_MIN(result, pt->seconds);
+       result = PARA_MAX(result, 0UL);
+       return result;
+}
+
+static void wipe_receiver_node(struct play_task *pt)
+{
+       PARA_NOTICE_LOG("cleaning up receiver node\n");
+       btr_remove_node(&pt->rn.btrn);
+       afh_recv->close(&pt->rn);
+       afh_recv->free_config(pt->rn.conf);
+       memset(&pt->rn, 0, sizeof(struct receiver_node));
+}
+
+/* returns: 0 not eof, 1: eof, < 0: fatal error.  */
+static int get_playback_error(struct play_task *pt)
+{
+       int err;
+
+       if (!pt->wn.task)
+               return 0;
+       err = task_status(pt->wn.task);
+       if (err >= 0)
+               return 0;
+       if (task_status(pt->fn.task) >= 0)
+               return 0;
+       if (task_status(pt->rn.task) >= 0)
+               return 0;
+       if (err == -E_BTR_EOF || err == -E_RECV_EOF || err == -E_EOF
+                       || err == -E_WRITE_COMMON_EOF)
+               return 1;
+       return err;
+}
+
+static int eof_cleanup(struct play_task *pt)
+{
+       struct writer *w = writers + DEFAULT_WRITER;
+       const struct filter *decoder = filter_get(pt->fn.filter_num);
+       int ret;
+
+       ret = get_playback_error(pt);
+       if (ret == 0)
+               return ret;
+       PARA_NOTICE_LOG("cleaning up wn/fn nodes\n");
+       task_reap(&pt->wn.task);
+       w->close(&pt->wn);
+       btr_remove_node(&pt->wn.btrn);
+       w->free_config(pt->wn.conf);
+       memset(&pt->wn, 0, sizeof(struct writer_node));
+
+       task_reap(&pt->fn.task);
+       decoder->close(&pt->fn);
+       btr_remove_node(&pt->fn.btrn);
+       free(pt->fn.conf);
+       memset(&pt->fn, 0, sizeof(struct filter_node));
+
+       task_reap(&pt->rn.task);
+       btr_remove_node(&pt->rn.btrn);
+       /*
+        * On eof (ret > 0), we do not wipe the receiver node struct until a
+        * new file is loaded because we still need it for jumping around when
+        * paused.
+        */
+       if (ret < 0)
+               wipe_receiver_node(pt);
+       return ret;
+}
+
+static int shuffle_compare(__a_unused const void *a, __a_unused const void *b)
+{
+       return para_random(100) - 50;
+}
+
+static void shuffle(char **base, size_t num)
+{
+       srandom(time(NULL));
+       qsort(base, num, sizeof(char *), shuffle_compare);
+}
+
+static struct btr_node *new_recv_btrn(struct receiver_node *rn)
+{
+       return btr_new_node(&(struct btr_node_description)
+               EMBRACE(.name = afh_recv->name, .context = rn,
+                       .handler = afh_recv->execute));
+}
+
+static int open_new_file(struct play_task *pt)
+{
+       int ret;
+       char *tmp, *path = conf.inputs[pt->next_file], *afh_recv_conf[] =
+               {"play", "-f", path, "-b", "0", NULL};
+
+       PARA_NOTICE_LOG("next file: %s\n", path);
+       wipe_receiver_node(pt);
+       pt->start_chunk = 0;
+       pt->rn.btrn = new_recv_btrn(&pt->rn);
+       pt->rn.conf = afh_recv->parse_config(ARRAY_SIZE(afh_recv_conf) - 1,
+               afh_recv_conf);
+       assert(pt->rn.conf);
+       pt->rn.receiver = afh_recv;
+       ret = afh_recv->open(&pt->rn);
+       if (ret < 0) {
+               PARA_ERROR_LOG("could not open %s: %s\n", path,
+                       para_strerror(-ret));
+               goto fail;
+       }
+       pt->audio_format_num = ret;
+       free(pt->afhi_txt);
+       ret = btr_exec_up(pt->rn.btrn, "afhi", &pt->afhi_txt);
+       if (ret < 0)
+               pt->afhi_txt = make_message("[afhi command failed]\n");
+       ret = btr_exec_up(pt->rn.btrn, "seconds_total", &tmp);
+       if (ret < 0)
+               pt->seconds = 1;
+       else {
+               int32_t x;
+               ret = para_atoi32(tmp, &x);
+               pt->seconds = ret < 0? 1 : x;
+               free(tmp);
+               tmp = NULL;
+       }
+       ret = btr_exec_up(pt->rn.btrn, "chunks_total", &tmp);
+       if (ret < 0)
+               pt->num_chunks = 1;
+       else {
+               int32_t x;
+               ret = para_atoi32(tmp, &x);
+               pt->num_chunks = ret < 0? 1 : x;
+               free(tmp);
+               tmp = NULL;
+       }
+       return 1;
+fail:
+       wipe_receiver_node(pt);
+       return ret;
+}
+
+static int load_file(struct play_task *pt)
+{
+       const char *af;
+       char *tmp, buf[20];
+       int ret;
+       const struct filter *decoder;
+
+       btr_remove_node(&pt->rn.btrn);
+       if (!pt->rn.receiver || pt->next_file != pt->current_file) {
+               ret = open_new_file(pt);
+               if (ret < 0)
+                       return ret;
+       } else {
+               pt->rn.btrn = new_recv_btrn(&pt->rn);
+               sprintf(buf, "repos %lu", pt->start_chunk);
+               ret = btr_exec_up(pt->rn.btrn, buf, &tmp);
+               if (ret < 0)
+                       PARA_CRIT_LOG("repos failed: %s\n", para_strerror(-ret));
+               freep(&tmp);
+       }
+       if (!pt->playing)
+               return 0;
+       /* set up decoding filter */
+       af = audio_format_name(pt->audio_format_num);
+       tmp = make_message("%sdec", af);
+       ret = check_filter_arg(tmp, &pt->fn.conf);
+       freep(&tmp);
+       if (ret < 0)
+               goto fail;
+       pt->fn.filter_num = ret;
+       decoder = filter_get(ret);
+       pt->fn.btrn = btr_new_node(&(struct btr_node_description)
+               EMBRACE(.name = decoder->name, .parent = pt->rn.btrn,
+                       .handler = decoder->execute, .context = &pt->fn));
+       decoder->open(&pt->fn);
+
+       /* setup default writer */
+       pt->wn.conf = check_writer_arg_or_die(NULL, &pt->wn.writer_num);
+
+       /* success, register tasks */
+       pt->rn.task = task_register(
+               &(struct task_info) {
+                       .name = afh_recv->name,
+                       .pre_select = afh_recv->pre_select,
+                       .post_select = afh_recv->post_select,
+                       .context = &pt->rn
+               }, &sched);
+       sprintf(buf, "%s decoder", af);
+       pt->fn.task = task_register(
+               &(struct task_info) {
+                       .name = buf,
+                       .pre_select = decoder->pre_select,
+                       .post_select = decoder->post_select,
+                       .context = &pt->fn
+               }, &sched);
+       register_writer_node(&pt->wn, pt->fn.btrn, &sched);
+       return 1;
+fail:
+       wipe_receiver_node(pt);
+       return ret;
+}
+
+static int next_valid_file(struct play_task *pt)
+{
+       int i, j = pt->current_file;
+
+       FOR_EACH_PLAYLIST_FILE(i) {
+               j = (j + 1) % conf.inputs_num;
+               if (!pt->invalid[j])
+                       return j;
+       }
+       return -E_NO_VALID_FILES;
+}
+
+static int load_next_file(struct play_task *pt)
+{
+       int ret;
+
+again:
+       if (pt->rq == CRT_NONE) {
+               pt->start_chunk = 0;
+               ret = next_valid_file(pt);
+               if (ret < 0)
+                       return ret;
+               pt->next_file = ret;
+       } else if (pt->rq == CRT_REPOS)
+               pt->next_file = pt->current_file;
+       ret = load_file(pt);
+       if (ret < 0) {
+               pt->invalid[pt->next_file] = true;
+               pt->rq = CRT_NONE;
+               goto again;
+       }
+       pt->current_file = pt->next_file;
+       pt->rq = CRT_NONE;
+       return ret;
+}
+
+static void kill_stream(struct play_task *pt)
+{
+       if (pt->wn.task)
+               task_notify(pt->wn.task, E_EOF);
+}
+
+#ifdef HAVE_READLINE
+
+/* only called from com_prev(), nec. only if we have readline */
+static int previous_valid_file(struct play_task *pt)
+{
+       int i, j = pt->current_file;
+
+       FOR_EACH_PLAYLIST_FILE(i) {
+               j--;
+               if (j < 0)
+                       j = conf.inputs_num - 1;
+               if (!pt->invalid[j])
+                       return j;
+       }
+       return -E_NO_VALID_FILES;
+}
+
+#include "interactive.h"
+
+/*
+ * Define the default (internal) key mappings and helper functions to get the
+ * key sequence or the command from a key id, which is what we obtain from
+ * i9e/readline when the key is pressed.
+ *
+ * In some of these helper functions we could return pointers to the constant
+ * arrays defined below. However, for others we can not, so let's better be
+ * consistent and allocate all returned strings on the heap.
+ */
+
+#define INTERNAL_KEYMAP_ENTRIES \
+       KEYMAP_ENTRY("^", "jmp 0"), \
+       KEYMAP_ENTRY("1", "jmp 10"), \
+       KEYMAP_ENTRY("2", "jmp 21"), \
+       KEYMAP_ENTRY("3", "jmp 32"), \
+       KEYMAP_ENTRY("4", "jmp 43"), \
+       KEYMAP_ENTRY("5", "jmp 54"), \
+       KEYMAP_ENTRY("6", "jmp 65"), \
+       KEYMAP_ENTRY("7", "jmp 76"), \
+       KEYMAP_ENTRY("8", "jmp 87"), \
+       KEYMAP_ENTRY("9", "jmp 98"), \
+       KEYMAP_ENTRY("+", "next"), \
+       KEYMAP_ENTRY("-", "prev"), \
+       KEYMAP_ENTRY(":", "bg"), \
+       KEYMAP_ENTRY("i", "info"), \
+       KEYMAP_ENTRY("l", "ls"), \
+       KEYMAP_ENTRY("s", "play"), \
+       KEYMAP_ENTRY("p", "pause"), \
+       KEYMAP_ENTRY("q", "quit"), \
+       KEYMAP_ENTRY("?", "help"), \
+       KEYMAP_ENTRY("\033[D", "ff -10"), \
+       KEYMAP_ENTRY("\033[C", "ff 10"), \
+       KEYMAP_ENTRY("\033[A", "ff 60"), \
+       KEYMAP_ENTRY("\033[B", "ff -60"), \
+
+#define KEYMAP_ENTRY(a, b) a
+static const char *default_keyseqs[] = {INTERNAL_KEYMAP_ENTRIES};
+#undef KEYMAP_ENTRY
+#define KEYMAP_ENTRY(a, b) b
+static const char *default_commands[] = {INTERNAL_KEYMAP_ENTRIES};
+#undef KEYMAP_ENTRY
+#define NUM_INTERNALLY_MAPPED_KEYS ARRAY_SIZE(default_commands)
+#define NUM_MAPPED_KEYS (NUM_INTERNALLY_MAPPED_KEYS + conf.key_map_given)
+#define FOR_EACH_MAPPED_KEY(i) for (i = 0; i < NUM_MAPPED_KEYS; i++)
+
+static inline bool is_internal_key(int key)
+{
+       return key < NUM_INTERNALLY_MAPPED_KEYS;
+}
+
+/* for internal keys, the key id is just the array index. */
+static inline int get_internal_key_map_idx(int key)
+{
+       assert(is_internal_key(key));
+       return key;
+}
+
+/*
+ * For user-defined keys, we have to subtract NUM_INTERNALLY_MAPPED_KEYS. The
+ * difference is the index to the array of user defined key maps.
+ */
+static inline int get_user_key_map_idx(int key)
+{
+       assert(!is_internal_key(key));
+       return key - NUM_INTERNALLY_MAPPED_KEYS;
+}
+
+static inline int get_key_map_idx(int key)
+{
+       return is_internal_key(key)?
+               get_internal_key_map_idx(key) : get_user_key_map_idx(key);
+}
+
+static inline char *get_user_key_map_arg(int key)
+{
+       return conf.key_map_arg[get_user_key_map_idx(key)];
+}
+
+static inline char *get_internal_key_map_seq(int key)
+{
+       return para_strdup(default_keyseqs[get_internal_key_map_idx(key)]);
+}
+
+static char *get_user_key_map_seq(int key)
+{
+       const char *kma = get_user_key_map_arg(key);
+       const char *p = strchr(kma + 1, ':');
+       char *result;
+       int len;
+
+       if (!p)
+               return NULL;
+       len = p - kma;
+       result = para_malloc(len + 1);
+       memcpy(result, kma, len);
+       result[len] = '\0';
+       return result;
+}
+
+static char *get_key_map_seq(int key)
+{
+       return is_internal_key(key)?
+               get_internal_key_map_seq(key) : get_user_key_map_seq(key);
+}
+
+static inline char *get_internal_key_map_cmd(int key)
+{
+       return para_strdup(default_commands[get_internal_key_map_idx(key)]);
+}
+
+static char *get_user_key_map_cmd(int key)
+{
+       const char *kma = get_user_key_map_arg(key);
+       const char *p = strchr(kma + 1, ':');
+
+       if (!p)
+               return NULL;
+       return para_strdup(p + 1);
+}
+
+static char *get_key_map_cmd(int key)
+{
+       return is_internal_key(key)?
+               get_internal_key_map_cmd(key) : get_user_key_map_cmd(key);
+}
+
+static char **get_mapped_keyseqs(void)
+{
+       char **result;
+       int i;
+
+       result = para_malloc((NUM_MAPPED_KEYS + 1) * sizeof(char *));
+       FOR_EACH_MAPPED_KEY(i) {
+               int idx = get_key_map_idx(i);
+               char *seq = get_key_map_seq(i);
+               char *cmd = get_key_map_cmd(i);
+               bool internal = is_internal_key(i);
+               PARA_DEBUG_LOG("%s key sequence #%d: %s -> %s\n",
+                       internal? "internal" : "user-defined",
+                       idx, seq, cmd);
+               result[i] = seq;
+               free(cmd);
+       }
+       result[i] = NULL;
+       return result;
+}
+
+#include "play.command_list.h"
+
+typedef int play_command_handler_t(struct play_task *, int, char**);
+static play_command_handler_t PLAY_COMMAND_HANDLERS;
+
+/* defines one command of para_play */
+struct pp_command {
+       const char *name;
+       play_command_handler_t *handler;
+       const char *description;
+       const char *usage;
+       const char *help;
+};
+
+static struct pp_command pp_cmds[] = {DEFINE_PLAY_CMD_ARRAY};
+#define FOR_EACH_COMMAND(c) for (c = 0; pp_cmds[c].name; c++)
+
+#include "play.completion.h"
+static struct i9e_completer pp_completers[];
+
+I9E_DUMMY_COMPLETER(jmp);
+I9E_DUMMY_COMPLETER(next);
+I9E_DUMMY_COMPLETER(prev);
+I9E_DUMMY_COMPLETER(fg);
+I9E_DUMMY_COMPLETER(bg);
+I9E_DUMMY_COMPLETER(ls);
+I9E_DUMMY_COMPLETER(info);
+I9E_DUMMY_COMPLETER(play);
+I9E_DUMMY_COMPLETER(pause);
+I9E_DUMMY_COMPLETER(stop);
+I9E_DUMMY_COMPLETER(tasks);
+I9E_DUMMY_COMPLETER(quit);
+I9E_DUMMY_COMPLETER(ff);
+
+static void help_completer(struct i9e_completion_info *ci,
+               struct i9e_completion_result *result)
+{
+       result->matches = i9e_complete_commands(ci->word, pp_completers);
+}
+
+static struct i9e_completer pp_completers[] = {PLAY_COMPLETERS {.name = NULL}};
+
+static void attach_stdout(struct play_task *pt, const char *name)
+{
+       if (pt->btrn)
+               return;
+       pt->btrn = btr_new_node(&(struct btr_node_description)
+               EMBRACE(.name = name));
+       i9e_attach_to_stdout(pt->btrn);
+}
+
+static void detach_stdout(struct play_task *pt)
+{
+       btr_remove_node(&pt->btrn);
+}
+
+static int com_quit(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       pt->rq = CRT_TERM_RQ;
+       return 0;
+}
+
+static int com_help(struct play_task *pt, int argc, char **argv)
+{
+       int i;
+       char *buf;
+       size_t sz;
+
+       if (argc > 2)
+               return -E_PLAY_SYNTAX;
+       if (argc < 2) {
+               if (pt->background)
+                       FOR_EACH_COMMAND(i) {
+                               sz = xasprintf(&buf, "%s\t%s\n", pp_cmds[i].name,
+                                       pp_cmds[i].description);
+                               btr_add_output(buf, sz, pt->btrn);
+                       }
+               else {
+                       FOR_EACH_MAPPED_KEY(i) {
+                               bool internal = is_internal_key(i);
+                               int idx = get_key_map_idx(i);
+                               char *seq = get_key_map_seq(i);
+                               char *cmd = get_key_map_cmd(i);
+                               sz = xasprintf(&buf,
+                                       "%s key #%d: %s -> %s\n",
+                                       internal? "internal" : "user-defined",
+                                       idx, seq, cmd);
+                               btr_add_output(buf, sz, pt->btrn);
+                               free(seq);
+                               free(cmd);
+                       }
+               }
+               return 0;
+       }
+       FOR_EACH_COMMAND(i) {
+               if (strcmp(pp_cmds[i].name, argv[1]))
+                       continue;
+               sz = xasprintf(&buf,
+                       "NAME\n\t%s -- %s\n"
+                       "SYNOPSIS\n\t%s\n"
+                       "DESCRIPTION\n%s\n",
+                       argv[1],
+                       pp_cmds[i].description,
+                       pp_cmds[i].usage,
+                       pp_cmds[i].help
+               );
+               btr_add_output(buf, sz, pt->btrn);
+               return 0;
+       }
+       return -E_BAD_PLAY_CMD;
+}
+
+static int com_info(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       char *buf;
+       size_t sz;
+       static char dflt[] = "[no information available]";
+
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       sz = xasprintf(&buf, "playlist_pos: %u\npath: %s\n",
+               pt->current_file, conf.inputs[pt->current_file]);
+       btr_add_output(buf, sz, pt->btrn);
+       buf = pt->afhi_txt? pt->afhi_txt : dflt;
+       btr_add_output_dont_free(buf, strlen(buf), pt->btrn);
+       return 0;
+}
+
+static void list_file(struct play_task *pt, int num)
+{
+       char *buf;
+       size_t sz;
+
+       sz = xasprintf(&buf, "%s %4u %s\n", num == pt->current_file?
+               "*" : " ", num, conf.inputs[num]);
+       btr_add_output(buf, sz, pt->btrn);
+}
+
+static int com_tasks(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       static char state;
+       char *buf;
+       size_t sz;
+
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+
+       buf = get_task_list(&sched);
+       btr_add_output(buf, strlen(buf), pt->btrn);
+       state = get_playback_state(pt);
+       sz = xasprintf(&buf, "state: %c\n", state);
+       btr_add_output(buf, sz, pt->btrn);
+       return 0;
+}
+
+static int com_ls(struct play_task *pt, int argc, char **argv)
+{
+       int i, j, ret;
+
+       if (argc == 1) {
+               FOR_EACH_PLAYLIST_FILE(i)
+                       list_file(pt, i);
+               return 0;
+       }
+       for (j = 1; j < argc; j++) {
+               FOR_EACH_PLAYLIST_FILE(i) {
+                       ret = fnmatch(argv[j], conf.inputs[i], 0);
+                       if (ret == 0) /* match */
+                               list_file(pt, i);
+               }
+       }
+       return 0;
+}
+
+static int com_play(struct play_task *pt, int argc, char **argv)
+{
+       int32_t x;
+       int ret;
+       char state;
+
+       if (argc > 2)
+               return -E_PLAY_SYNTAX;
+       state = get_playback_state(pt);
+       if (argc == 1) {
+               if (state == 'P')
+                       return 0;
+               pt->next_file = pt->current_file;
+               pt->rq = CRT_REPOS;
+               pt->playing = true;
+               return 0;
+       }
+       ret = para_atoi32(argv[1], &x);
+       if (ret < 0)
+               return ret;
+       if (x < 0 || x >= conf.inputs_num)
+               return -ERRNO_TO_PARA_ERROR(EINVAL);
+       kill_stream(pt);
+       pt->next_file = x;
+       pt->rq = CRT_FILE_CHANGE;
+       return 0;
+}
+
+static int com_pause(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       char state;
+       long unsigned seconds, ss;
+
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       state = get_playback_state(pt);
+       pt->playing = false;
+       if (state != 'P')
+               return 0;
+       seconds = get_play_time(pt);
+       pt->playing = false;
+       ss = 0;
+       if (pt->seconds > 0)
+               ss = seconds * pt->num_chunks / pt->seconds + 1;
+       ss = PARA_MAX(ss, 0UL);
+       ss = PARA_MIN(ss, pt->num_chunks);
+       pt->start_chunk = ss;
+       kill_stream(pt);
+       return 0;
+}
+
+static int com_prev(struct play_task *pt, int argc, __a_unused char **argv)
+
+{
+       int ret;
+
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       ret = previous_valid_file(pt);
+       if (ret < 0)
+               return ret;
+       kill_stream(pt);
+       pt->next_file = ret;
+       pt->rq = CRT_FILE_CHANGE;
+       pt->start_chunk = 0;
+       return 0;
+}
+
+static int com_next(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       int ret;
+
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       ret = next_valid_file(pt);
+       if (ret < 0)
+               return ret;
+       kill_stream(pt);
+       pt->next_file = ret;
+       pt->rq = CRT_FILE_CHANGE;
+       pt->start_chunk = 0;
+       return 0;
+}
+
+static int com_fg(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       pt->background = false;
+       return 0;
+}
+
+static int com_bg(struct play_task *pt, int argc, __a_unused char **argv)
+{
+       if (argc != 1)
+               return -E_PLAY_SYNTAX;
+       pt->background = true;
+       return 0;
+}
+
+static int com_jmp(struct play_task *pt, int argc, char **argv)
+{
+       int32_t percent;
+       int ret;
+
+       if (argc != 2)
+               return -E_PLAY_SYNTAX;
+       ret = para_atoi32(argv[1], &percent);
+       if (ret < 0)
+               return ret;
+       if (percent < 0 || percent > 100)
+               return -ERRNO_TO_PARA_ERROR(EINVAL);
+       if (percent == 100)
+               return com_next(pt, 1, (char *[]){"next", NULL});
+       if (pt->playing && !pt->fn.btrn)
+               return 0;
+       pt->start_chunk = percent * pt->num_chunks / 100;
+       if (!pt->playing)
+               return 0;
+       pt->rq = CRT_REPOS;
+       kill_stream(pt);
+       return 0;
+}
+
+static int com_ff(struct play_task *pt, int argc, char **argv)
+{
+       int32_t seconds;
+       int ret;
+
+       if (argc != 2)
+               return -E_PLAY_SYNTAX;
+       ret = para_atoi32(argv[1], &seconds);
+       if (ret < 0)
+               return ret;
+       if (pt->playing && !pt->fn.btrn)
+               return 0;
+       seconds += get_play_time(pt);
+       seconds = PARA_MIN(seconds, (typeof(seconds))pt->seconds - 4);
+       seconds = PARA_MAX(seconds, 0);
+       pt->start_chunk = pt->num_chunks * seconds / pt->seconds;
+       pt->start_chunk = PARA_MIN(pt->start_chunk, pt->num_chunks - 1);
+       pt->start_chunk = PARA_MAX(pt->start_chunk, 0UL);
+       if (!pt->playing)
+               return 0;
+       pt->rq = CRT_REPOS;
+       kill_stream(pt);
+       return 0;
+}
+
+static int run_command(char *line, struct play_task *pt)
+{
+       int i, ret, argc;
+       char **argv = NULL;
+
+       attach_stdout(pt, __FUNCTION__);
+       ret = create_argv(line, " ", &argv);
+       if (ret < 0) {
+               PARA_ERROR_LOG("parse error: %s\n", para_strerror(-ret));
+               return 0;
+       }
+       if (ret == 0)
+               goto out;
+       argc = ret;
+       FOR_EACH_COMMAND(i) {
+               if (strcmp(pp_cmds[i].name, argv[0]))
+                       continue;
+               ret = pp_cmds[i].handler(pt, argc, argv);
+               if (ret < 0)
+                       PARA_WARNING_LOG("%s: %s\n", pt->background?
+                               "" : argv[0], para_strerror(-ret));
+               ret = 1;
+               goto out;
+       }
+       PARA_WARNING_LOG("invalid command: %s\n", argv[0]);
+       ret = 0;
+out:
+       free_argv(argv);
+       return ret;
+}
+
+static int play_i9e_line_handler(char *line)
+{
+       return run_command(line, &play_task);
+}
+
+static int play_i9e_key_handler(int key)
+{
+       struct play_task *pt = &play_task;
+       int idx = get_key_map_idx(key);
+       char *seq = get_key_map_seq(key);
+       char *cmd = get_key_map_cmd(key);
+       bool internal = is_internal_key(key);
+
+       PARA_NOTICE_LOG("pressed %d: %s key #%d (%s -> %s)\n",
+               key, internal? "internal" : "user-defined",
+               idx, seq, cmd);
+       run_command(cmd, pt);
+       free(seq);
+       free(cmd);
+       pt->next_update = *now;
+       return 0;
+}
+
+static struct i9e_client_info ici = {
+       .fds = {0, 1, 2},
+       .prompt = "para_play> ",
+       .line_handler = play_i9e_line_handler,
+       .key_handler = play_i9e_key_handler,
+       .completers = pp_completers,
+};
+
+static void sigint_handler(int sig)
+{
+       play_task.background = true;
+       i9e_signal_dispatch(sig);
+}
+
+/*
+ * We start with para_log() set to the standard log function which writes to
+ * stderr. Once the i9e subsystem has been initialized, we switch to the i9e
+ * log facility.
+ */
+static void session_open(struct play_task *pt)
+{
+       int ret;
+       char *history_file;
+       struct sigaction act;
+
+       PARA_NOTICE_LOG("\n%s\n", version_text("play"));
+       if (conf.history_file_given)
+               history_file = para_strdup(conf.history_file_arg);
+       else {
+               char *home = para_homedir();
+               history_file = make_message("%s/.paraslash/play.history",
+                       home);
+               free(home);
+       }
+       ici.history_file = history_file;
+       ici.loglevel = loglevel;
+
+       act.sa_handler = sigint_handler;
+       sigemptyset(&act.sa_mask);
+       act.sa_flags = 0;
+       sigaction(SIGINT, &act, NULL);
+       act.sa_handler = i9e_signal_dispatch;
+       sigemptyset(&act.sa_mask);
+       act.sa_flags = 0;
+       sigaction(SIGWINCH, &act, NULL);
+       sched.select_function = i9e_select;
+
+       ici.bound_keyseqs = get_mapped_keyseqs();
+       pt->btrn = ici.producer = btr_new_node(&(struct btr_node_description)
+               EMBRACE(.name = __FUNCTION__));
+       ret = i9e_open(&ici, &sched);
+       if (ret < 0)
+               goto out;
+       para_log = i9e_log;
+       return;
+out:
+       free(history_file);
+       if (ret >= 0)
+               return;
+       PARA_EMERG_LOG("fatal: %s\n", para_strerror(-ret));
+       exit(EXIT_FAILURE);
+}
+
+static void session_update_time_string(struct play_task *pt, char *str, unsigned len)
+{
+       if (pt->background)
+               return;
+       if (pt->btrn) {
+               if (btr_get_output_queue_size(pt->btrn) > 0)
+                       return;
+               if (btr_get_input_queue_size(pt->btrn) > 0)
+                       return;
+       }
+       ie9_print_status_bar(str, len);
+}
+
+/*
+ * If we are about to die we must call i9e_close() to reset the terminal.
+ * However, i9e_close() must be called in *this* context, i.e. from
+ * play_task.post_select() rather than from i9e_post_select(), because
+ * otherwise i9e would access freed memory upon return. So the play task must
+ * stay alive until the i9e task terminates.
+ *
+ * We achieve this by sending a fake SIGTERM signal via i9e_signal_dispatch()
+ * and reschedule. In the next iteration, i9e->post_select returns an error and
+ * terminates. Subsequent calls to i9e_get_error() then return negative and we
+ * are allowed to call i9e_close() and terminate as well.
+ */
+static int session_post_select(__a_unused struct sched *s, struct play_task *pt)
+{
+       int ret;
+
+       if (pt->background)
+               detach_stdout(pt);
+       else
+               attach_stdout(pt, __FUNCTION__);
+       ret = i9e_get_error();
+       if (ret < 0) {
+               kill_stream(pt);
+               i9e_close();
+               para_log = stderr_log;
+               free(ici.history_file);
+               return ret;
+       }
+       if (get_playback_state(pt) == 'X')
+               i9e_signal_dispatch(SIGTERM);
+       return 0;
+}
+
+#else /* HAVE_READLINE */
+
+static int session_post_select(struct sched *s, struct play_task *pt)
+{
+       char c;
+
+       if (!FD_ISSET(STDIN_FILENO, &s->rfds))
+               return 0;
+       if (read(STDIN_FILENO, &c, 1))
+               do_nothing;
+       kill_stream(pt);
+       return 1;
+}
+
+static void session_open(__a_unused struct play_task *pt)
+{
+}
+
+static void session_update_time_string(__a_unused struct play_task *pt,
+               char *str, __a_unused unsigned len)
+{
+       printf("\r%s     ", str);
+       fflush(stdout);
+}
+#endif /* HAVE_READLINE */
+
+static void play_pre_select(struct sched *s, void *context)
+{
+       struct play_task *pt = context;
+       char state;
+
+       para_fd_set(STDIN_FILENO, &s->rfds, &s->max_fileno);
+       state = get_playback_state(pt);
+       if (state == 'R' || state == 'F' || state == 'X')
+               return sched_min_delay(s);
+       sched_request_barrier_or_min_delay(&pt->next_update, s);
+}
+
+static unsigned get_time_string(struct play_task *pt, char **result)
+{
+       int seconds, length;
+       char state = get_playback_state(pt);
+
+       /* do not return anything if things are about to change */
+       if (state != 'P' && state != 'U') {
+               *result = NULL;
+               return 0;
+       }
+       length = pt->seconds;
+       if (length == 0)
+               return xasprintf(result, "0:00 [0:00] (0%%/0:00)");
+       seconds = get_play_time(pt);
+       return xasprintf(result, "#%u: %d:%02d [%d:%02d] (%d%%/%d:%02d) %s",
+               pt->current_file,
+               seconds / 60,
+               seconds % 60,
+               (length - seconds) / 60,
+               (length - seconds) % 60,
+               length? (seconds * 100 + length / 2) / length : 0,
+               length / 60,
+               length % 60,
+               conf.inputs[pt->current_file]
+       );
+}
+
+static int play_post_select(struct sched *s, void *context)
+{
+       struct play_task *pt = context;
+       int ret;
+
+       ret = eof_cleanup(pt);
+       if (ret < 0) {
+               pt->rq = CRT_TERM_RQ;
+               return 0;
+       }
+       ret = session_post_select(s, pt);
+       if (ret < 0)
+               goto out;
+       if (!pt->wn.btrn && !pt->fn.btrn) {
+               char state = get_playback_state(pt);
+               if (state == 'P' || state == 'R' || state == 'F') {
+                       PARA_NOTICE_LOG("state: %c\n", state);
+                       ret = load_next_file(pt);
+                       if (ret < 0) {
+                               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+                               pt->rq = CRT_TERM_RQ;
+                               ret = 1;
+                               goto out;
+                       }
+                       pt->next_update = *now;
+               }
+       }
+       if (tv_diff(now, &pt->next_update, NULL) >= 0) {
+               char *str;
+               unsigned len = get_time_string(pt, &str);
+               struct timeval delay = {.tv_sec = 0, .tv_usec = 100 * 1000};
+               if (str && len > 0)
+                       session_update_time_string(pt, str, len);
+               free(str);
+               tv_add(now, &delay, &pt->next_update);
+       }
+       ret = 1;
+out:
+       return ret;
+}
+
+/**
+ * The main function of para_play.
+ *
+ * \param argc Standard.
+ * \param argv Standard.
+ *
+ * \return \p EXIT_FAILURE or \p EXIT_SUCCESS.
+ */
 int main(int argc, char *argv[])
 {
+       int ret;
+       struct play_task *pt = &play_task;
+
        /* needed this early to make help work */
        recv_init();
        filter_init();
        writer_init();
 
+       sched.default_timeout.tv_sec = 5;
+
        parse_config_or_die(argc, argv);
-       return 0;
+       if (conf.inputs_num == 0)
+               print_help_and_die();
+       check_afh_receiver_or_die();
+
+       session_open(pt);
+       if (conf.randomize_given)
+               shuffle(conf.inputs, conf.inputs_num);
+       pt->invalid = para_calloc(sizeof(*pt->invalid) * conf.inputs_num);
+       pt->rq = CRT_FILE_CHANGE;
+       pt->current_file = conf.inputs_num - 1;
+       pt->playing = true;
+       pt->task = task_register(&(struct task_info){
+               .name = "play",
+               .pre_select = play_pre_select,
+               .post_select = play_post_select,
+               .context = pt,
+       }, &sched);
+       ret = schedule(&sched);
+       sched_shutdown(&sched);
+       if (ret < 0)
+               PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+       return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
 }