I loaded and played multiple sounds with web audio api at the same time. Is there any way to stop all sounds?
ex: a button to stop all sounds now.
Since I have more than 10 sounds playing at the same time, I dont wanna manually use noteOff(0) (or stop(0) ) for each sound source.
The easiest way to achieve the effect you want, then, is to connect() them all to a gain node which is then connected to the destination, and set gain.gain.value = 0.
It won't actually stop them, of course, but it will silence them.
Related
I am trying to make an app that can play multiple videos at once. The goal is to record multiple music voices and then play them together. I am using the video_player plugin and each video has its own player. The problem is that when I start playing, it is not reliable when each player will start. So, I thought if I load the files before start playing this difference could be reduced. But I couldn't figure out how to do it and if it is possible to do. So, is there a way to load those files to reduce this difference? If there is another way to achieve my goal I would be glad to know. Thank you!
I have a similar problem where I want to control the exact moment the video starts playing.
For now, the best way seems to be (assuming you have a _controller constructed already)
await _controller.initialize()
await _controller.play()
await _controller.pause()
After that, the video starts playing almost immediately. For my purposes it’s good enough but if you need to control this down to the millisecond for synchronization purposes it might not cut it.
You might also want to hide the video and mute it during those first calls.
I am working on an app that allows the user to create a sort of dub. There is an audio file playing, and the user can tap at certain moments to insert sound (kind of like a censor button.) I'm wondering how to go about capturing the final product.
Capturing audio directly from the iPhone seems the easiest route, as the user already hears the finished product as it is made. However, I can't find anything on how to do this. If not possible, are there any suggestions?
The best way would probably be to be using the AV Foundation framework for mixing and then buffering the audio as well as playing it. This would allow for a high abstraction level while guaranteeing both played back and saved audio to be equal.
Apart from that: from a How can I achieve this with minimum code-perspective, without more information about your setup, the question is way too broad and/or opinion-based.
You will have to work with buffers. Don't know right now how it is done in Swift but you can implement it in Obj-C and then bridge it out.
You can refer to this answers here in StackOverflow (They are a bit old)
https://stackoverflow.com/a/11218339/2683201
https://stackoverflow.com/a/10101877/2683201
and a project also exists (but is in Obj-C)
https://github.com/alexbw/novocaine
Mainly the idea for your case would be to have 2 separated buffers and your sound effect.
Then, you will be playing from buffer A (your music) and copying played data into buffer B (final Output) unless you are playing the effect. In wich case you will be copying the effect data into your buffer B.
Other option is to do it offline:
Play your music (or audio) and keep a timer running synced with the elapsed time of your "to be censored audio".
Save the timestamp of when you start and end tapping the censor button (for example).
Overlap buffer A with your effect in those recorded (start-end) timestamps.
Save the buffer as a file (or do whatever you need to do with it)
UPDATE:
You should take a look into the Apple implementation of something like this:
https://developer.apple.com/library/ios/samplecode/AVAEMixerSample/Introduction/Intro.html
What is the correct way to begin playback of a video from a specific time?
Currently, the approach we use is to check at an interval whether it's possible to seek via currentTime and then seek. The problem with this is, when the video fullscreen view pops up, it begins playback from the beginning for up to a second before seeking.
I've tried events such as onloadmetadata and canplay, but those seem to happen too early.
Added information:
It seems the very best I can do is to set a timer that tries to set currentTime repeatedly as soon as play() is called, however, this is not immediate enough. The video loads from the beginning, and after about a second, depending on the device, jumps. This is a problem for me as it provides an unsatisfactory experience to the user.
It seems like there can be no solution which does better, but I'm trying to see if there is either:
a) something clever/undocumented which I have missed which allows you to either seek before loading or otherwise indicate that the video needs to start not from 00:00 but from an arbitrary point
b) something clever which allows you to hide the video while it's playing and not display it until it has seeked (So you would see a longer delay on the phone before the fullscreen video window pops up, but it would start immediately where I need it to instead of seeking)
do something like this;
var video = document.getElementsById("video");
video.currentTime = starttimeoffset;
more Information can be found on this page dedicated to video time offset howtos
For desktop browser Chrome/Safari, you can append #t=starttimeoffsetinseconds to your video src url to make it start from certain position.
For iOS device, the best we can do is to listen for the timeupdated event, and do the seek in there. I guess this is the same as your original approach of using a timer.
-R
I have a bunch of sounds I want to play. Right now I'm using AVAudioPlayer. A new sound should start when the user clicks a button. The url property of AVAudioPlayer is read-only. I'd rather not have to release and re-alloc the object every time I want a new sound played. What would be the best way to do this? Is there a different class I need to use?
The absolute easiest way to play sound is Playing UI Sound Effects or Invoking Vibration Using System Sound Services. Essentially you call AudioServicesCreateSystemSoundID() and AudioServicesPlaySystemSound(). Creating a system sound is relatively expensive and playback stops when it's disposed with AudioServicesDisposeSystemSoundID() anyway, so you really want to cache them:
Create them at app launch (or possibly the first time the sound is played). You can keep them in an NSDictionary keyed by sound file name and store the sound ID in an NSValue, or so.
If you can be bothered, dispose them when your app exits, is backgrounded, or on a memory warning.
The biggest caveat is that only a few sound formats are supported for "system sounds"; apple seems to recommend IMA4 (afconvert -f caff -d ima4 input.file output.caf and optionally -c 1 if you're happy with mono).
That said, it's pretty much perfect for playing short sounds provided you don't mind one-at-a-time sounds (it restarts playback if you play a sound while it's already playing). I suspect it's also played directly by the kernel (you can set a flag to make it continue playback when your app exits), which probably means it's more efficient CPU-wise. It might mix with sounds played by AVAudioPlayer.
I am trying to develop a simple iPhone app. I need to play sound within a loop.
How can Play Audio file in loop without any interruption ?
Take a look at the new AVAudioPlayer class in the 2.2 release:
http://developer.apple.com/iphone/library/documentation/AVFoundation/Reference/AVAudioPlayerClassReference/Reference/Reference.html
It has functionality for looping sounds.
I really don't know the iPhone SDK at all, but this should be quick: try making the sound itself looping. That way, you should be able to play it with just a single call, and won't need to worry about timing the repeat properly to restart it at the exact right moment.
For instance, WAV files have very flexible support for looping, and any decent audio editor should let you set looping points.
The AVAudioPlayer has numberOfLoops property where you can specify the number of times you want the audio to loop.