I need to be able to have multiple tracks playing at the same time, and also changing to other tracks with as little latency as possible. I don't think SoundPool will work, since it are real audiotracks and not so much samples. I'm trying to make like some sort of mixing application, where you can select certain tracks to play, and others not to play.
Any idea on how to do this, suggestions/tips ?
Related
In the application, songs will have been split into multiple tracks, one track per instrument.
I need to be able to play all the tracks simultaneously.
I have seen that MediaPlayer is not able to do this, indeed having 5 to 10 separate tracks would cause too much latency.
SoundPool states that it is specifically for short sounds and so is inappropriate for this.
It would appear that AudioTrack would be the answer, but that requires decoding each mp3 into pcm data before playing it.
So, here are my questions -
Even though I have not found any, do any tutorials exist demonstrating how to achieve this ?
Can anyone advise on how to play multiple audiotracks simultaneously ?
Are there any existing examples on how to decode mp3 files using the NDK ?
I'm working on an android app that plays video (using video view). the video is meant to have both music (left and right) and narration, but I want to selectively be able to turn off the narration track in the MediaPlayer.
Is the way to do this correctly to encode by mp4 video file with 3 audio tracks (right left and narration) and then turn off the naration audio track with deselectTrack()?
Not clear to me from the documentation that MediaPlayer can handle more than 2 audio tracks.
If the audio tracks are limited to 2, would it make sense to run two media player simultaneously (synching them up with seekTo())when I want the narration track to play?
Thanks.
Sorry to burst your bubble, but...
1) You have a misunderstanding about what a "track" denotes. A track can have multiple channels (e.g., a stereo track has left and right channels). As I understand it, stereo is the extent of the Android AudioTrack implementation at present. I haven't yet checked if the OpenSL implementation is more extensive than the Java API.
2) Only 1 audio track can be selected at a time, so you wouldn't be able to have background and narration simultaneously in the way you were thinking.
3) Audio tracks can only be selected in the prepared state (i.e., not after playback has started). The documentation mentions this limitation is not ideal, so it will probably change in the future. If not for this problem, your goal could be accomplished with two audio tracks encoded in the stream, one with both background & narration, the other just background.
You will probably find it difficult to synchronize two MediaPlayers, but I haven't tried. Maybe this approach would be acceptable for your situation, although be forewarned the seekTo method isn't accurate. It depends on the encoding of the files.
Something I would try if I were you is to have two complete encoded videos, one with narration, the other without. Use two MediaPlayers and keep them both prepared. When you want to switch use seekTo to put the correct one at (or near) the desired location. That way you don't have to worry about synchronization. If the video is large, this method could use significantly more resources, though.
I'm writing my first android app, trying to playback two 10min soundfiles synchronously (imagine an instrumental track and an acapella), to be able to change the volume of each track independently). I am using two MediaPlayers for this, since a SoundPool is targeted at shorter audio samples as far as I read.
Now my problem is that, when pausing and resuming the playback, sometimes the players are not synchronous anymore, even though I set their positions to the same value before resuming playback.
I know that this is kind of inevitable, because they cannot be started at exactly the same moment and they may require different amounts of time for starting playback, but: Is there maybe any other approach to meet my requirements?
You can take a look at JetPlayer, this may accomplish what you want as far as synchronization.
To use it you create audio channels (your instrument channel and vocal channel) as MIDI files in a track and the player can keep them synchronized while allowing you to mute or unmute the different channels as appropriate.
The user guide for creating JET resouces can be found here.
My team and I are nearly done developing a music application for iPhone and Android that allows users to create their own music, built by playing and overlapping sampled sounds (up to 16 at a time). We are looking for a way to allow users to share these songs by embedding an audio player in our website which will (like the Android and iPhone applications already do) take the songs, which are expressed as a string representing pitch, duration, start time, and instrument, and convert them into a single playable audio file (any format).
We have looked into SoundManager 2 and WebAudio, and have run into the same problem with both: stopping sounds creates beeping or popping sounds that cannot be removed. Does anyone know of another framework or API that we should look into? A little googling also made sfplay stand out, but there isn't very much documentation on it. Any other suggestions?
Thanks!
There are still a lot of problems with javascript/html5 audio. WebAudio is very powerful but not very portable. Soundmanager 2 is less powerful, but more portable. You should not be hearing clicks/discontinuities with either library unless you are doing something wrong, but there are problems with synchronization and so on with browser-based audio.
That's why most people doing "serious" audio on the web are using java applets or flash, which won't work on devices.
Currently my code plays a sound when there is contact between any objects in my game using andEngine and Box2D and the walls, the problem I have is that when contact is made with any objects it starts again I understand why this is happening. What I want to do if possible is keep playing the sound while also playing it for another collision. I think I may need to use threads but I am unsure how to do this in java for android.
#Override
public void beginContact(Contact contact)
{
Rattle.this.mExplosionSound.play();
}
UPDATE: I don't seem to have been able to fix the issue but I know that what I need to do is play this sound multiple times simultaneously, I have tried threads and the soundPool but got no luck with either still not sure what to do.
It seems you have only one instance of the sound. Then you call play on the same sound twice, therefore it stops playing and starts from the beginning.
Imagine having one CD player - you press play, the music starts to play. You press play again and the player starts reading the track from the beginning. What you need is two players, therefore you may need two instances of the same sound.
(I don't have much experience with sound on Android so I may be wrong, please take the advice with a grain of salt.)
Even I was developing a game some time back and I found a similar problem. You should use SoundPool to play short sounds like crashing and collisions. here are some good linkswhich helped me. Link 1, link 2.