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**TheOldPresbyope** · 06-03-2020, 03:53 PM

What is this Python script you refer to? Examining it would be the first step in a reverse-engineering process to find out what LMS API is being accessed or what stream decoding method is being used to capture the metadata of the currently playing track. I still haven't found either approach documented on the InterWeb™, which leaves me dubious.

Regards,
Kent

mancio61 · (This post was last modified: 06-03-2020, 04:31 PM by mancio61.)

(06-03-2020, 03:53 PM)TheOldPresbyope Wrote: What is this Python script you refer to? Examining it would be the first step in a reverse-engineering process to find out what LMS API is being accessed or what stream decoding method is being used to capture the metadata of the currently playing track. I still haven't found either approach documented on the InterWeb™, which leaves me dubious.

Regards,
Kent

Try to attach the .py file but with no success. Anyway here's the portions of code that create the connection with the LMS Server, and the one able to retrieve from it the music info

1) Constants and initial comments

Code:
LMS_ENABLED = False

LMS_SERVER = "localhost"

LMS_PORT = 9090

LMS_USER = ""

LMS_PASSWORD = ""

# Set this to MAC address of the Player you want to monitor.

# THis should be the MAC of the RaspDac system if using Max2Play with SqueezePlayer

# Note: if you have another Logitech Media Server running in your network, it is entirely

#       possible that your player has decided to join it, instead of the LMS on Max2Play

#       To fix this, go to the SqueezeServer interface and change move the player to the

#       correct server.

LMS_PLAYER = "00:01:02:aa:bb:cc"

Note: don't ask me the meaning of the above comment, is quite obscured for me....

2 ) Establishing Connection:

Code:
        if LMS_ENABLED:

            for i in range (1,ATTEMPTS):

                try:

                    # Connect to the LMS daemon

                    self.lmsserver = pylms.server.Server(LMS_SERVER, LMS_PORT, LMS_USER, LMS_PASSWORD)

                    self.lmsserver.connect()

                    # Find correct player

                    players = self.lmsserver.get_players()

                    for p in players:

                        ### Need to find out how to get the MAC address from player

                        if p.get_ref().lower() == LMS_PLAYER.lower():

                            self.lmsplayer = p

                            break

                    if self.lmsplayer is None:

                        self.lmsplayer = self.lmsserver.get_players()[0]

                        if self.lmsplayer is None:

                            raise Exception('Could not find any LMS player')

                    break

                except (socket_error, AttributeError, IndexError):

                    logging.debug("Connect attempt {0} to LMS server failed".format(i))

                    time.sleep(2)

            else:

                # After the alloted number of attempts did not succeed in connecting

                logging.warning("Unable to connect to LMS service on startup")

3 - Retrieving info from LMS Server

Code:
    def status_lms(self):

        # Try to get status from LMS daemon

        try:

            lms_status = self.lmsplayer.get_mode()

        except:

            # Try to reestablish connection to daemon

            try:

                self.lmsserver = pylms.server.Server(LMS_SERVER, LMS_PORT, LMS_USER, LMS_PASSWORD)

                self.lmsserver.connect()

                # Find correct player

                players = self.lmsserver.get_players()

                for p in players:

                    ### Need to find out how to get the MAC address from player

                    if p.get_ref().lower() == LMS_PLAYER.lower():

                        self.lmsplayer = p

                        break

                if self.lmsplayer is None:

                    self.lmsplayer = self.lmsserver.get_players()[0]

                    if self.lmsplayer is None:

                        raise Exception('Could not find any LMS player')

                lms_status = self.lmsplayer.get_mode()

            except (socket_error, AttributeError, IndexError):

                logging.debug("Could not get status from LMS daemon")

                return { 'state':u"stop", 'artist':u"", 'title':u"", 'album':u"", 'remaining':u"", 'current':0, 'duration':0, 'position':u"", 'volume':0, 'playlist_display':u"", 'playlist_position':0, 'playlist_count':0, 'bitrate':u"", 'type':u"", 'current_time':u""}

          if lms_status == "play":

            import urllib

            artist = urllib.unquote(str(self.lmsplayer.request("artist ?", True))).decode('utf-8')

            title = urllib.unquote(str(self.lmsplayer.request("title ?", True))).decode('utf-8')

            album = urllib.unquote(str(self.lmsplayer.request("album ?", True))).decode('utf-8')

            playlist_position = int(self.lmsplayer.request("playlist index ?"))+1

            playlist_count = self.lmsplayer.playlist_track_count()

            volume = self.lmsplayer.get_volume()

            current = self.lmsplayer.get_time_elapsed()

            duration = self.lmsplayer.get_track_duration()

            url = self.lmsplayer.get_track_path()

            # Get bitrate and tracktype if they are available.  Try blocks used to prevent array out of bounds exception if values are not found

            try:

                bitrate = urllib.unquote(str(self.lmsplayer.request("songinfo 2 1 url:"+url+" tags:r", True))).decode('utf-8').split("bitrate:", 1)[1]

            except:

                bitrate = u""

            try:

                tracktype = urllib.unquote(str(self.lmsplayer.request("songinfo 2 1 url:"+url+" tags:o", True))).decode('utf-8').split("type:",1)[1]

            except:

                tracktype = u""

            playlist_display = "{0}/{1}".format(playlist_position, playlist_count)

            # If the track count is greater than 1, we are playing from a playlist and can display track position and track count

            if self.lmsplayer.playlist_track_count() > 1:

                playlist_display = "{0}/{1}".format(playlist_position, playlist_count)

            # if the track count is exactly 1, this is either a short playlist or it is streaming

            elif self.lmsplayer.playlist_track_count() == 1:

                try:

                    # if streaming

                    if self.lmsplayer.playlist_get_info()[0]['duration'] == 0.0:

                        playlist_display = "Streaming"

                    # it really is a short playlist

                    else:

                        playlist_display = "{0}/{1}".format(playlist_position, playlist_count)

                except KeyError:

                    logging.debug("In LMS couldn't get valid track information")

                    playlist_display = u""

            else:

                logging.debug("In LMS track length is <= 0")

                playlist_display = u""

              # since we are returning the info as a JSON formatted return, convert

              # any None's into reasonable values

            if artist is None: artist = u""

            if title is None: title = u""

            if album is None: album = u""

            if current is None: current = 0

            if volume is None: volume = 0

            if bitrate is None: bitrate = u""

            if tracktype is None: tracktype = u""

            if duration is None: duration = 0

            # if duration is not available, then suppress its display

            if int(duration) > 0:

                timepos = time.strftime("%M:%S", time.gmtime(int(current))) + "/" + time.strftime("%M:%S", time.gmtime(int(duration)))

                remaining = time.strftime("%M:%S", time.gmtime(int(duration) - int(current) ) )

            else:

                timepos = time.strftime("%M:%S", time.gmtime(int(current)))

                remaining = timepos

            return { 'state':u"play", 'artist':artist, 'title':title, 'album':album, 'remaining':remaining, 'current':current, 'duration':duration, 'position':timepos, 'volume':volume, 'playlist_display':playlist_display,'playlist_position':playlist_position, 'playlist_count':playlist_count, 'bitrate':bitrate, 'type':tracktype }

          else:

            return { 'state':u"stop", 'artist':u"", 'title':u"", 'album':u"", 'remaining':u"", 'current':0, 'duration':0, 'position':u"", 'volume':0, 'playlist_display':u"", 'playlist_position':0, 'playlist_count':0, 'bitrate':u"", 'type':u""}

The returned state object is then passed to the rendering part of the script, that uses it to send info to the OLED display

Hope this helps the discussion

Andrea

**TheOldPresbyope** · (This post was last modified: 06-03-2020, 04:46 PM by TheOldPresbyope.)

Cool. Thanks.

So, searching the InterWEB™ on the class name pylms I infer this script is using jinglemansweep's PyLMS module.

Ok. I see what he's doing. Basically, as a third party, asking LMS what is the current album, artist, track you are sending to a specified player, e.g., using a LMS API.

jinglemansweep refers to a 4-year old document describing the HTTP API on a french website http://tutoriels.domotique-store.fr/cont...-http.html

Don't know why I didn't run across this before (or why the API is not documented in more official places) but that's the breaks.

Regards,
Kent

mancio61 · 06-03-2020, 05:12 PM

Here's the original project on GitHub , it seems to come from Audiophonics...

https://github.com/dhrone/Raspdac-Display

steve4star · 10-27-2023, 08:06 PM

I had a play with the AirPlay decoder and was able to create a HTML page that had track info and relevant cover art.

Using the example, I extended it to write a HTML file, but I understand that writing cuurentsong.txt might be a better approach.
I am not familiar enough with how the moode code changes the display when airplay is active.

To test I run the following:

Code:
cat /tmp/shairport-sync-metadata | shairport-sync-metadata-reader | sudo ~/reader.py

Where the reader has the following:

Code:
#!/usr/bin/env python3

# @TheOldPresbyope

# this code was copied from

# https://appcodelabs.com/show-artist-song-metadata-using-airplay-on-raspberry-pi

# and modified to print to console as if it were a three-line display

# NOTE - doesn't clear previous value of specific key when no new value is received

# @steve4star

# Adapted to clear key values when track/album identifier changes

# Writes to HTML page /var/www/airplay.html 

# NOTE needs permission 755 for html and jpg file

import sys

import re

import os

import shutil

# a device isn't needed but let's define a dummy just

# to keep the same render() syntax as in the original code

device = "null"

artist = ""

track = ""

album = ""

tracklength = ""

picture = ""

pictureURL =""

status = ""

progress = ""

ID = ""

def extract(line):

   #Progress String "388666875/630526809/706186875".

   m = re.match('^(Title|Artist|Album Name|Track length|Progress String): \"(.*?)\"\.$', line)

   if m:

       return m.group(1), m.group(2)

   else:

       #Track length: 300000 milliseconds.

       m = re.match('^(Track length): (.*?) milliseconds\.$', line)

       if m:

           return m.group(1), m.group(2)

       else:

           #Picture received, length 98020 bytes.

           m = re.match('^(Picture received, length) (.*?) bytes\.$', line)

           if m:

               return m.group(1), m.group(2)

           else:

               m = re.match('^(Play Session) (.*?)\.$', line)

               if m:

                   return m.group(1), m.group(2)

               else:

                   m = re.match('^(Persistent ID): (.*?)\.$', line)

                   if m:

                       return m.group(1), m.group(2)

                   else:

                       return None, None

def update(key, val):

   global artist, album, track, tracklength, picture, status, progress, ID

   if key == "Artist":

       artist = val

   elif key == "Album Name":

       album = val

   elif key == "Title":

        track = val

   elif key == "Track length":

        tracklength = val

   elif key == "Picture received, length":

        picture = val

   elif key == "Progress String":

        progress = val

   elif key == "Play Session":

        status = val

   elif key == "Persistent ID": 

        if ID != val: # new item, clear cached values

           ID = val

           artist = album = track = tracklength = picture = progress = ""

def render(device):

   global pictureURL

   sTime=""

   # print to console instead of writing output to a device

   # use an ASCII escape sequence to imitate a three-line display

   print(f'\u001b[2J\

ID: {ID}\n\

Artist: {artist}\n\

Album Name: {album}\n\

Title: {track}\n\

Cover: {pictureURL}\n\

Status: {status}')

   if tracklength != "": 

        mill_sec = int(tracklength)

        total_sec = mill_sec / 1000

        hours = int(total_sec // 3600 )

        min = int((total_sec // 60) % 60)

        sec = int(total_sec % 60)

        sTime = f"{hours:02d}:{min:02d}:{sec:02d}"

        print(f"Length: {sTime}")

   if picture != "": 

        # directory/folder path

        dir_path = r'/tmp/shairport-sync/.cache/coverart'

        res = []

        for file_path in os.listdir(dir_path):

            if os.path.isfile(os.path.join(dir_path, file_path)):

                res.append(file_path)

        if res:

            pictureURL = res[-1:][0]

            shutil.copyfile( f'{dir_path}/{pictureURL}', '/var/www/images/airplay.jpg' )

   with open('/var/www/airplay.html', 'w') as html:

      html.write(f'<!DOCTYPE html>\n\

<html>\n\

<head><title>Airplay Metadata</title><meta http-equiv="refresh" content="60"></head>\n\

<body>\n\

  <table>\n\

    <tbody>\n\

      <tr><td>Artist</td><td>{artist}</td></tr>\n\

      <tr><td>Album Title</td><td>{album}</td></tr>\n\

      <tr><td>Track Title</td><td>{track}</td></tr>\n\

      <tr><td>Track Length</td><td>{sTime}</td></tr>\n\

      <tr><td><img src="/images/airplay.jpg"></td><td>{status}</td></tr>\n\

    </tbody>\n\

  </table>\n\

</body>\n\

</html>\n')

# Create devices

   # deleted all the device code

# Welcome message

   # No, let's not

# Main loop

try:

   while True:

       line = sys.stdin.readline()

       key, val = extract(line)

       if key and val:

           update(key, val)

           render(device)

except KeyboardInterrupt:

   sys.stdout.flush()

   pass

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