Tutorial: Custom Media Streaming for Android's MediaPlayer

biosopher

I have had absolutely no luck streaming audio using the built-in MediaPlayer functionality so I decided to write my own streaming utility for the MediaPlayer.

My solution is now documented as a tutorial on my blog including including source code:

blog.pocketjourney.com.

Here's a sneak peak at a few screenshots:

Please check it out & leave a comment on my blog if you have questions.

Best of luck,
biosopher

plusminus · Posted: Sat Apr 05, 2008 12:15 pm Post subject:

Hello acopernicus,

I haven't actually tried it, but it looks really nice Exclamation

I assume there is a short break, when the MediaPlayer is stopped, file copied and MediaPlayer restarted, right Question

Did you think about submitting that tutorial to the Android Tutorial Challenge Question

You could win an Android Shirt Smile

Looking at the text you have written, the chance is pretty good Wink

Best Regards,
plusminus

biosopher · Posted: Sat Apr 05, 2008 6:01 pm Post subject:

Thanks for the recommendation about submitting into the tutorial challenge, +-. The TC is an excellent idea for getting more people to contribute back to the community.

As for the copying of the file while streaming, it's actually very quick and typically only occurs once. So while their is a slight stutter in audio playback, it's barely noticeable & isn't any different from your experience streaming a Quicktime or Flash video.

Cheers & thanks much for hosting this great site!

Biosopher

Stephen.Ada · Junior Developer Joined: 10 Mar 2008 Posts: 10

hi, acopernicus
i can't open ur blog on browser, it always displayed "The requested URL could not be retrieved", could u pls post the code here or upload it as attachment?
thx very much ^_^

biosopher · Posted: Mon Apr 21, 2008 6:26 am Post subject:

Everything appears to be working fine from my browser:

Here are the links again:

blog
http://blog.pocketjourney.com

I would advice visiting the blog, as the tutorial description should be very helpful. If you want though, you can get the code directly here:

Tutorial #3 source
http://www.pocketjourney.com/downloads/tutorials/tutorial3.zip

vol · Junior Developer Joined: 16 Apr 2008 Posts: 15

I'm glad to know that I'm not the only one getting confused and frustrated here. I'm assuming that the error codes of "what" and "extra" mean "google" and "developer" as in "google 1, developer 0" Mad

Oh well. I guess I'll have to work on something else. I was hoping to the media player to teach myself services, but I suppose there's no joy for streaming, so I'll have to stick with local files, or just predownload them first.

marielisacr · Junior Developer Joined: 21 May 2008 Posts: 12

Hello acopernicus,

This is a great tutorial. I’m traying to add a funtionality, when i press a button i would like to change to the next song (i am playing a list of songs). It start play the music ok but after listening a few songs or after a while the emulator crash, it restart by itself, i don’t know what is going on.

I think than can be a problem of memory, but i am erasing all the files and making flush of the FileOutputStream.

I really appreciate your help. Thanks

biosopher · Posted: Thu May 22, 2008 4:00 am Post subject:

Hi marielisacr,

Not sure if you mean your app is crashing (which I haven't experienced myself) or the app is crashing (which means you should try to catch exception that's being thrown) or just the MediaPlayer is crashing (which I've experienced and means you need to look at the stack trace).

I've experienced I/O problems & threading issues that initially made me think my MediaPlayer problems were in Android. Now though, I've developed a very robust framework around MediaPlayer as a Service that has been able to successfully play tens of audio files in a row without crashing.

So the short answer is that I need to know more about what you mean by crashing and whether you've got a stack trace yet.

Thanks,
Biosopher

marielisacr · Junior Developer Joined: 21 May 2008 Posts: 12

Hi,

this is the problem. I have a list of songs that i want to play. The songs play ok. I have a button to change the songs. I wait until the buffer is almost full to change to another song and i do that many times, after a few songs the emulator restart the application, it doesn´t show any message or error in the screen and i put down what i have in the logs.

I am using your tutorial to play the songs and when i change to another song i am calling a method that set the variable isInterrupted to true so the thread can end and then put goblal variable to they initial state. In this case i am watting to the current thread ends to return to the initial method and avoid problems with the global variables and have threads that never die. After all this i call to the function startStreamingAudio with the new path.

This is the log:

biosopher · Posted: Thu May 22, 2008 4:03 pm Post subject:

Hmmm...it's curious that you're not getting more of an error dump.

What version of the SDK are you using?

biosopher · Posted: Thu May 22, 2008 4:19 pm Post subject:

How big are your audio files? If they're too big, you may be running out of disk space on the device. That should cause an IOException though and would be caught (I assume you're writing all those error to the log).

As a first step though, you can ensure you are deleting all your files after playing them. I actually have created a cache of for my audio files that is set to a max of 50MB. Since I have no problem storing and playing files up to that size limit, I doubt your disk is filling up...but it's possible.

When exactly does the error occur?

1) Right after you click the button & before the next audio starts to download.
2) While the new audio is buffering.
3) After the new audio is buffered and is being transferred to the player
4) After the new audio starts playing a little
5) ....?....

- Biosopher

marielisacr · Junior Developer Joined: 21 May 2008 Posts: 12

I'm using regular audio files, like about 4 MB. the problem occurs after the new audio starts playing a little, I mean everything is going fine and suddently it restarts. I am deleting the two files so i guess it can't be a memory problem eather.

Here is how I am doing:

First I call to the method play after i have the song selected by the user. Then i call to the fuction initControls with the path and the song's name

biosopher · Posted: Thu May 22, 2008 5:39 pm Post subject:

Let's first track down where, in the process of playing the new file, does the crash occur.

1) File plays a little and crashes when it hits the end of the buffered content.
2) File plays and crashes when the fully loaded content is transferred to the MediaPlayer for continued play.

It's hard to tease these two scenarios apart because you're not sending the actual file size & time. If you were, you could look at the progress bar to see what was happening with the buffer.

I recommend logging this information and posting it here:

A) Log when the user presses play
B) Log when the initial buffer starts being downloaded
C) Log every 250Kb of file download
D) Log when the initial buffer download is completed
E) Log when the initial buffer is transferred to a new file for playing
F) Log when you start playing the audio file
G) Continue logging every 250Kb of file download
H) Log when the file is completely downloaded
J) Log when the full file is being transferred to a new file for playing
J) Log when you swap the prior buffered file for the now completely downloaded file
K) Log when you start playing the now completely downloaded file

That should give us enough to see when, in the download process, the crash occurs.

Post you log output here when you have it.

biosopher

marielisacr · Junior Developer Joined: 21 May 2008 Posts: 12

Hi, i did what you said, here is the log. At the end i got the message that the apication i dead and then restarted.