Create FIFO for current track playback progress

README.md

@@ -83,6 +83,11 @@ An example::
     comment=
 
 
+Additionally, a fifo named `position` will also be created and will be updated
+roughly once a second with the position and the total duration of the
+currently playing track, space-separated.
+
+
 Thanks
 ------
 Big thanks to David Hammerton for releasing an ALAC decoder, which is reproduced here in full.
@@ -100,7 +105,7 @@ Contributors to version 1.x
 * [Peter Körner](http://mazdermind.de)
 * [Muffinman](http://github.com/therealmuffin)
 * [Skaman](http://github.com/skaman)
-* [Weston](http://github.com/wnielson)
+* [Weston Nielson](http://github.com/wnielson)
 * [allesblinkt](http://github.com/allesblinkt)
 
 Contributors to version 0.x
@@ -128,4 +133,4 @@ Known Ports and Tools
     * [shairport4w](http://sf.net/projects/shairport4w)
 * OS X:
     * [ShairportMenu](https://github.com/rcarlsen/ShairPortMenu), a GUI wrapper as a menu widget
-    * [MacShairport](https://github.com/joshaber/MacShairport)
+    * [MacShairport](https://github.com/joshaber/MacShairport)

metadata.c

@@ -41,6 +41,7 @@
 metadata player_meta;
 static int fd = -1;
 static int dirty = 0;
+static int fdp = -1;
 
 void metadata_set(char** field, const char* value) {
     if (*field) {
@@ -77,6 +78,31 @@ static void metadata_close(void) {
     fd = -1;
 }
 
+void metadata_position_open(void) {
+  if (!config.meta_dir)
+    return;
+
+  const char fn[] = "position";
+  size_t pl = strlen(config.meta_dir) + 1 + strlen(fn);
+
+  char* path = malloc(pl+1);
+  snprintf(path, pl+1, "%s/%s", config.meta_dir, fn);
+
+  if (mkfifo(path, 0644) && errno != EEXIST)
+    die("Could not create metadata FIFO %s", path);
+
+  fdp = open(path, O_WRONLY | O_NONBLOCK);
+  if (fdp < 0)
+    debug(1, "Could not open metadata position FIFO %s. Will try again later.", path);
+
+  free(path);
+}
+
+static void metadata_position_close(void) {
+  close(fdp);
+  fdp = -1;
+}
+
 static void print_one(const char *name, const char *value) {
     write_unchecked(fd, name, strlen(name));
     write_unchecked(fd, "=", 1);
@@ -114,6 +140,43 @@ void metadata_write(void) {
         metadata_close();
 }
 
+void metadata_position_write(void) {
+  int ret;
+
+  if (player_meta.paused)
+    return;
+
+  // readers may go away and come back
+  if (fdp < 0)
+    metadata_position_open();
+  if (fdp < 0)
+    return;
+
+  char  number[10];
+  int   chars;
+
+  //
+  // XXX: The sample rate is always 44100 Hertz, right?
+  //
+  unsigned int position = (player_meta.position-player_meta.start)/44100;
+  unsigned int length   = (player_meta.end-player_meta.start)/44100;
+
+  if (length == 0 || position > length)
+    return;
+
+  chars = sprintf(number, "%d", position);
+  write_unchecked(fdp, number, chars);
+
+  write_unchecked(fdp, " ", 1);
+
+  chars = sprintf(number, "%d", length);
+  write_unchecked(fdp, number, chars);
+
+  ret = write(fdp, "\n", 1);
+  if (ret < 1)    // no reader
+    metadata_position_close();
+}
+
 void metadata_cover_image(const char *buf, int len, const char *ext) {
     if (!config.meta_dir)
         return;

metadata.h

@@ -10,12 +10,19 @@ typedef struct {
     char *artwork;
     char *comment;
     char *genre;
+
+    unsigned int paused;
+    unsigned int position;
+    unsigned int start;
+    unsigned int curr;
+    unsigned int end;
 } metadata;
 
 void metadata_set(char** field, const char* value);
 void metadata_open(void);
 void metadata_write(void);
 void metadata_cover_image(const char *buf, int len, const char *ext);
+void metadata_position_write(void);
 
 extern metadata player_meta;
 

player.c

@@ -476,6 +476,7 @@ static void *player_thread_func(void *arg) {
 #endif
             play_samples = stuff_buffer(bf_playback_rate, inbuf, outbuf);
 
+        player_meta.paused = 0;
         config.output->play(outbuf, play_samples);
     }
 
@@ -496,6 +497,7 @@ void player_volume(double f) {
     }
 }
 void player_flush(void) {
+    player_meta.paused = 1;
     pthread_mutex_lock(&ab_mutex);
     ab_resync();
     pthread_mutex_unlock(&ab_mutex);

rtp.c

@@ -34,6 +34,7 @@
 #include <netdb.h>
 #include "common.h"
 #include "player.h"
+#include "metadata.h"
 
 // only one RTP session can be active at a time.
 static int running = 0;
@@ -57,8 +58,14 @@ static void *rtp_receiver(void *arg) {
 
         ssize_t plen = nread;
         uint8_t type = packet[1] & ~0x80;
-        if (type == 0x54) // sync
+        if (type == 0x54) {  // sync
+            player_meta.position = (packet[4] << 24) |
+                                   (packet[5] << 16) |
+                                   (packet[6] << 8)  |
+                                   (packet[7]);
+            metadata_position_write();
             continue;
+        }
         if (type == 0x60 || type == 0x56) {   // audio data / resend
             pktp = packet;
             if (type==0x56) {

rtsp.c

@@ -410,7 +410,7 @@ static void handle_setup(rtsp_conn_info *conn,
     int sport = rtp_setup(&conn->remote, cport, tport);
     if (!sport)
         return;
-
+  
     player_play(&conn->stream);
 
     char resphdr[100];
@@ -445,6 +445,12 @@ static void handle_set_parameter_parameter(rtsp_conn_info *conn,
         } else if(!strncmp(cp, "progress: ", 10)) {
             char *progress = cp + 10;
             debug(1, "progress: %s\n", progress);
+
+            if (sscanf(progress, "%u/%u/%u", &(player_meta.start), &(player_meta.curr), &(player_meta.end)) != 3)
+            {
+              player_meta.position = 0;
+            }
+
         } else {
             debug(1, "unrecognised parameter: >>%s<< (%d)\n", cp, strlen(cp));
         }