Last.Fm Radio Stream Player Gadget 0.5 Released!

Update 08-06-2010: the last.fm gadget does not work anymore. Last.fm changed their client server protocols and therefore the gadget is not working anymore. I’m not using Last.fm anymore so i’m not planning on updating the gadget in the future

 

 

Last week my mailbox was flooded by mails of people who were telling me my Windows Vista Sidebar gadget to play Last.fm radio was broken.

I tested it myself and concluded that this was indeed the case. Last.fm changed their website last week and my guess is that they also changed their streaming service.

After a full night of debugging I found out what was the problem and I fixed it in a new version which can be now downloaded from the download area.

If you are interested in what was changed read on. The change was fairly simple, the protocol uses 2 handshakes to connect to the service. The first handshake is to connect to the scrobbling service. The second handshake is used to connect to the streaming service. Before last week requesting the mp3 stream was done by sending the sessionid of the first handshake. Now… it seems you have to send the sessionid you get with the second handshake. It took some time to figure this out but now everything seems to work fine again.

Protocol example:

Handshake 1 request:

http://ws.audioscrobbler.com/radio/handshake.php?version=1.4.2.58376&platform=win32&platformversion=Windows%20Vista&username=geertvdcruijsen&passwordmd5=
4d9309866b98863c3c3336e50392831b&language=en&player=winamp

Handshake 1 response from last.fm:

session=bbe5e763d1e1deb988595cecf1c21e9d stream_url=http://87.117.229.85:80/last.mp3?Session=bbe5e763d1e1deb988595cecf1c21e9d subscriber=0 framehack=0base_url=ws.audioscrobbler.com base_path=/radio info_message= fingerprint_upload_url=http://ws.audioscrobbler.com/fingerprint/upload.php permit_bootstrap=0

Handshake 2 request:

http://post.audioscrobbler.com/?hs=true&p=1.2&c=tst&v=1.3.1.1&u=geertvdcruijsen
&t=1217017120&a=2a060e72c7aae132e8fad06b741be806

Handshake 2 response from last.fm:

OK 7e5b82460d2a45e382b81c437ae6a87a http://post.audioscrobbler.com:80/np_1.2 http://87.117.229.205:80/protocol_1.2

Tune to the right radio channel:

http://ws.audioscrobbler.com/radio/adjust.php?session=bbe5e763d1e1deb988595cecf1c21e9d&url=lastfm://artist/muse

Response to channel change request from last.fm:

response=OK url=lastfm://artist/muse stationname= Muse’s Similar Artists discovery=true

Request metadata of stream:

http://ws.audioscrobbler.com/radio/xspf.php?sk=bbe5e763d1e1deb988595cecf1c21e9d
&discovery=0&desktop=1.3.1.1&time=1217017120321

I was happy to receive the mails of complaints because this is proof people are actually using my gadget :) Hopefully all problems are fixed now so happy listening!

Geert van der Cruijsen

Share on Facebook
Kick It on DotNetKicks.com
Shout it
Post on Twitter

Geert’s Vista Sidebar Gadget: Last.fm stream player version 0.1 released

I’ve been spending all my spare time this weekend to this project but now the player is ready for release 0.1 beta ;)

You can download the gadget here:

Last.fm Stream Player gadget Download

 

Information about how it’s made 

I’ve used wireshark to learn how the official client was using the last.fm protocol to get a mp3 stream since this wasnt documentated on the last.fm development documentation.

The different states in the protocol are:

  • handshake 1 (for streaming)
  • handshake 2 (for scrobbling)
  • tuning into a channel
  • get metadata of current song
  • send “now playing” information
  • at the end of song submit the scrobbled song
  • go to step 1

Since vista sidebar gadgets are html/javascript only the gadget is using an windows media player activex object to play the actual stream. All the handshake and other http requests are done by ajax calls to the audioscrobbler server. You can download the source on the download page also.

Have fun!

Geert van der Cruijsen

Share on Facebook
Kick It on DotNetKicks.com
Shout it
Post on Twitter

Creating a Microsoft Windows Vista Sidebar Gadget: Last.fm stream player – part 1

I’ve been using Windows Vista for 1 year now and I never used the sidebar before. I turned it off in the first week and never turned it back on again. Last week I decided to give it a try again and after filling it with some handy gadgets I thought it was time to build my own.

I didn’t know how to build a gadget so I looked it up on MSDN. There are some samples there but basically sidebar gadgets are small “web parts” totally build in HTML and JavaScript.

My first gadget I’m going to build is a Last.FM music player that can play a music stream from the Last.fm site with peoples favorite artists or with music matching a tag. Like you can do on the Last.fm site yourself.I went searching how I could get this stream to run in my gadget and I found out that Last.fm is using a fairly simple http based protocol which is described at http://www.audioscrobbler.net/development/protocol/I first started out with the 1.1 protocol because I didn’t read that there already was a 1.2 version. The 1.2 protocol has 3 states (handshake, now playing and submission) at the moment I’m writing this the only thing I have made is the handshake part and other functions to get metadata from the track.

I didnt make a nice user interface for my gadget yet and i didnt make anything to save your settings in. This will all be done in the upcoming days. If someone is really good in making a nice little interface (max 60 pixels wide) and feel like helping me out at this give me a call!. I’m not that good at grapic design.

btw. Coding Javascript in Visual Studio 2008 is really really nice. The intellisense really works great and it helps you write code a lot quicker.

I didnt put the sourcecode online yet since it’s all in the debugging phase right now and everything is still hard coded (user,password, radio channel etc). When everything is done i’ll post the full sourcecode here.

The functions that I’ve build now are shown in the following picture

The javascript code for these functions is shown below. (I will put it all on my site as a gadget when the whole thing is done).

This is all i could do in my spare time the last 2 days. I hope to get a lot further tomorrow and i’ll post the results again.

function Play()

{

duration = 0;

document.WindowsMediaPlayer.Stop();

 

GetMetaData();

currentlyPlaying = true;

 

setTimeout(“UpdateTimer()”, 1000);

 

}

function stop()

{

currentlyPlaying = false;

document.WindowsMediaPlayer.Stop();

}

function UpdateTimer()

{

if (currentlyPlaying)

{

if((document.WindowsMediaPlayer.CurrentPosition < duration) || (duration == 0))

{

document.getElementById(“counter”).innerHTML = ConvertSecondsToTime(document.WindowsMediaPlayer.CurrentPosition);setTimeout(“UpdateTimer()”, 950);

 

}

else

{

//alert(“restart”);

document.WindowsMediaPlayer.Stop();

SendHandshake();

}

}

else

{

stop();

}

}

function ConvertSecondsToTime(seconds)

{

var date = new Date(seconds * 1000);

var timeString = date.getMinutes() + “:” + date.getSeconds();

return timeString;

}

function makeRequest(url) { http_request = false;

if (window.XMLHttpRequest) { // Mozilla, Safari,…

http_request = new XMLHttpRequest();

if (http_request.overrideMimeType) {http_request.overrideMimeType(

‘text/xml’);

}

} else if (window.ActiveXObject) { // IE

try {

http_request = new ActiveXObject(“Msxml2.XMLHTTP”);}

catch (e) {

try {http_request =

new ActiveXObject(“Microsoft.XMLHTTP”);} catch (e) {alert(“error”);}

}

}

if (!http_request) {

alert(‘Giving up :( Cannot create an XMLHTTP instance’);

return false;

}

http_request.onreadystatechange = alertContents;

http_request.open(‘GET’, url, true); http_request.send(null);

}

function alertContents()

{

if (http_request.readyState == 4)

{

if (http_request.status == 200)

{

 

document.getElementById(“debug”).innerHTML = http_request.responseText;

 

switch(functionCall)

{

case “SendHandshake” :

GetHandshakeResponse(http_request.responseText);

break;case “TuneIn” :

GetTuneInResponse(http_request.responseText);

break;

case “GetMetaData” :

GetMetaDataResponse(http_request.responseText);

break;default:

alert(functionCall);

}

}

else

{

alert(‘There was a problem with the request.’ + http_request.status);

}

}

}

function SendHandshake()

{

var now = new Date();

now.setHours(now.getUTCHours(),now.getUTCMinutes(),now.getUTCSeconds(),now.getUTCMilliseconds());

var time = parseInt(now.getTime()/1000.0)

 

functionCall = “SendHandshake”;

url = “http://post.audioscrobbler.com/?hs=true&p=1.2&c=tst&v=1.3.1.1&u=”

url += “geertvdcruijsen”;url += “&t=”;

url += time;

url += “&a=”;

var md5String = MD5(“password”);

md5String += (time);

url += MD5(md5String);

makeRequest(url);

 

}

function GetHandshakeResponse(response)

{

arr_response = response.split(“\n”);

//stream_url = arr_response[1].split(“stream_url=”)[1];

session = arr_response[0].split(“session=”)[1];document.getElementById(“session”).innerHTML =response;

TuneIn();

 

}

function TuneIn()

{

functionCall = “TuneIn”;url = “http://ws.audioscrobbler.com/radio/adjust.php?session=”;

url += session;

url += “&url=”

url += “lastfm://artist/Chemical+Brothers/similarartists”;url += “&debug=0″;

makeRequest(url);

}

function GetTuneInResponse(response)

{

Play();

}

function GetMetaData()

{

var now = new Date();

functionCall = “GetMetaData”;url =

“http://ws.audioscrobbler.com/radio/xspf.php?sk=”;

url += session;

url += “&discovery=0&desktop=1.3.1.1&time=”

url += now.getTime();

makeRequest(url);

 

 

}

function GetMetaDataResponse(response)

{

arr_location = response.split(“<location>”);stream_url = arr_location[1].split(“</location>”)[0];

 

arr_duration = response.split(“<duration>”);duration = arr_duration[1].split(

“</duration>”)[0];

 

duration = (parseInt(duration,0)/1000) -3;

document.getElementById(“metadata”).innerHTML = ConvertSecondsToTime(duration);

 

document.WindowsMediaPlayer.fileName = stream_url;

document.WindowsMediaPlayer.Play();

}

<object id=”wmp” standby=”standby” type=”application/x-oleobject”> <embed type=”application/x-mplayer2″ id=”WindowsMediaPlayer” name=”WindowsMediaPlayer” showstatusbar=”-1″></embed>

</object>

Share on Facebook
Kick It on DotNetKicks.com
Shout it
Post on Twitter