predefined sections to mute in html5 audio - javascript

newbie in front end dev.
I've managed to use audio tag - really cool.
My need is to mute parts of the .wav that are predefined (for example mute between second 3 to second 8, and from second 32 to second 41) - meaning that if the user will listen to the wav, once getting to the configured sections - won't hear anything.
Is there a way to do it? or cannot be done?

Using .wav is not the most crossbrowser friendly, but it is possible to do what you want to do by monitoring the timeupdate event and when it reaches the time you want, e.g. 3 seconds, set the video's mute value to true, and then change it to false when it reaches 8 seconds.

Related

How to show the recording's length and the download option immediately after the recording is stopped?

I'm using the program in the following demo for a personal project.
https://mdn.github.io/web-dictaphone/
(more details: https://developer.mozilla.org/en-US/docs/Web/API/MediaStream_Recording_API/Using_the_MediaStream_Recording_API)
However, every time I make a recording, the length doesn't show immediately. Nor does the download option (the three-dot thing on the right).
the recording shown before I played it
I have to literally play the recording in order to make it show the recording duration and the download option.
the recording shown after I played it
Is there a way to improve this?

How to create a seconds counter that beeps every minute

I want to generate a "beep" sound every minute on the web browser.
For the "every minute" thing I rely on setInterval() since there is a seconds counter and I want to update the second counter every second. I am well aware of the non-real timing facts going on but it's not a big deal in this case.
The real deal is generating a short notification sound after every 59 seconds.
I am currently doing it using the audio API.
As follows:
a=new AudioContext();
function pitar(volumen, frecuencia, duracion){
v=a.createOscillator()
u=a.createGain()
v.connect(u)
v.frequency.value=frecuencia
v.type="square"
u.connect(a.destination)
u.gain.value=volumen*0.01
v.start(a.currentTime)
v.stop(a.currentTime+duracion*0.001)
}
pitar(999,220,300);
What is the problem?
This is not working on Safari.
This is not Working on chrome on iOS.
Specific errors:
Console log says for Chrome: "The AudioContext was not allowed to start. It must be resumed (or created) after a user gesture on the page."
It basically just works as expected on Firefox.
I tried to do it by checking if the AudioContext is available in the current browser and using a base64 encoded mp3 beep when it's not, following this older way:
How do I make JavaScript beep?
But it still won't work without the user interacting (id est. clicking somewhere on the page.)
I can somehow force the user to click once, by putting a button saying something like: "Hey, let's start".
But that will enable the click only for the first time, and not for every other minute.
I thought about creating a one minute audio file with 1 second beep and 59 seconds in silence and play it on replay. But even that would be problematic, since the beep would not be synchronized with the counter.
Another solution, would be to record a video and play that on loop.
Regarding this question - Play infinitely looping video on-load in HTML5 - it also won't work since autoplay requires muted on some browsers.
Any way of hiding the controlers and creating a custom javascript play button?
Or do you know any better way to achieve this?

How to control how much of a HTML5 video buffers?

Context
I am trying to loop several HTML5 videos one after the other. This is achieved via Javascript with an event listener listening for 'ended' - the video to end. At which point the url to the video is changed and video.play() is executed for the new URL.
For simplicity, lets say there are 2 videos that are to be (auto) played. After the second video finishes playing, it goes back to the first and plays that one (and the cycle continues). The videos will get cached on the user's device after they are first played.
TL-DR: Now what I want to achieve is to code a HTML5 video to be 'mobile friendly', in respect to mobile data plans.
I want the video to either stream when the page loads or buffer only a few seconds from after the point from where the user is watching. So if the user is 5 seconds into the video, the buffer extends to 15 seconds into the video (so 10 seconds of the video is buffered in case the network connection is weak). If the user pauses the video, the video stops buffering. Though the user won't have access to controls; they will be unable to forward, rewind or pause. I only gave the example of the user changing the point of the video to emphasise that I want control over how much the video has buffered and will buffer.
Alternatively, I want the video to stream to the user’s device. And only download that which needs to be immediately played. This is the less desirable option and is probably less desirable than leaving the video tag as it is since if the user has a dodgy connection, the video will play, stop, play, etc.
The reason for me wanting to achieve this is that I have noticed in Edge, IE, Firefox and Chrome that the video auto plays (good, that's what I want it to do) and plays while simultaneously downloading the whole video to their device (terrible). Of course this behaviour is expected, but practically, it should not do this. If users leave the site straight away, why would we want them to download a whole video they won't see?
Sort of but not entirely relevant, it doesn’t help:
HTML5 Video: Force abort of buffering
Simply put, the thread shows only hacks to hide the src and not any actual control over the buffer. I need to control the loading of the buffer in real time, relative to at what point the user is at, and not based on a 'pause' event. I would also like to know if there is a little-known supported method across most browsers (I only really need to worry about this on mobile) to achieve this, as opposed to a 'hack'.
Nevershowmyface: From what I can gather from the code, it stops the buffering every 0.5 seconds. There is no code for resuming the video? As for why this method will not work, it is not buffering relative to at what point the user is at. For all intents and purposes, it is still buffering the video in a linear fashion, without depending on a variable (the point at which the user is at). It's just doing it more slowly or 'in chunks'. If it loads another chunk just before the video runs out of video, I risk the video stopping and waiting to load again if the connection is poor.
Preload:none is useless here since the video is automatically played (notice bold auto at the top). I should have been more explicit. When the page loads, the video automatically plays. Preload loads the video before the play button is clicked on; preload:"none" does not load the video before play is clicked. But since there is no play button and the video plays once the page has loaded, it is a useless attribute.
My hopeless conclusion in regards to what should be a vital and basic feature
(not a rant)
From what I have found, there is no standardised way to achieve this and there are only ‘hacks’, as described in the post, which only serve to provide limited buffering functionality/ control in some browsers, potentially breaking other browsers and potentially having no effect in other browsers. In light of this, I’m on the verge of giving up on this task so thought I’d ask if anyone else has effectively managed to achieve this; it appears to have no support or has not even be considered in HTML5 or Javascript; I might be and hope I'm wrong – would be great to have this in Javascript.
Do other web developers not consider this when they use videos on their sites? I have spoken to other developers about this and they said the data usage from a site is not or is rarely the concern of the developer.
While I understand there are more important things to worry about, it goes without saying this would be very important for mobile users with low data plans.
Analysis:
The HTML5 audio element does not have a stop() function, nor does it
have an option where you can set the amount of data that it is allowed
to buffer, or a way of saying you want the element to stop buffering -
Don't confuse this with the 'preload' function, this only applies to
the element before the play button is clicked.
I have no clue why this is and why this functionality is not
available. If anyone can explain to me why these crucial functions are
not implemented in a standard that should make web development for
mobile phones better and more standardized I would love to know.
And before someone says the conclusion from that post was that this is currently impossible, note:
1) I am dealing with a video file, not an audio file. Slightly different context, where the file being buffered is significantly larger than an .mp3 file.
2) I am not trying to stop buffering altogether. I am trying to restrict it and keep it relative to the point of the video at which the user is at. So you could actually say I am trying to stop it but at an 'x' number of times after the point where the user's video is.

Mediaelement.js setCurrentTime sets the time incorrectly in Firefox and when using flash

I am using the mediaelement.js component for showing only parts of the video.
I've put a listener on the timeupdate event and Every time the video is playing a segment I wish to skip it jumps to the next segment by using setCurrentTime(). However the next time the timeupdate event is called the time is different then what was set (a few seconds before the time that was set).
this is my code:
var curr = t.media.getCurrentTime();
if (curr < segments[i][0]) {
console.debug(curr.toFixed(1)+' jumping to '+segments[i][0]+' in segment '+i+' ['+segments[i][0]+','+segments[i][1]+']');
t.media.setCurrentTime(segments[i][0]);
return;
}
when I log the current time after the code is executed it shows that the current time was updated correctly (for instance to 19) but when the event is called the next time the current time is wrong (15.3).
It only happens with firefox and when falling back to flash, in chrome it seems to work.
any ideas?
The problem is with the flash fallback. Apparently flash has a problem with the h.264 format and skipping to a specific time. Flash can only jump to keyframes in a H.264 format video and therefore when media element skips to a certain frame the flash player jumps to the nearest keyframe.
the problem can be fixed by setting a keyframe every couple of frame (for instance by using ffmpeg -g flag) but a better solution will be to keep the video in another format for the flash fallback.

Limitations of HTML5 Audio on iOS 4? Playlisting, background, etc

I've been evaluating HTML5 audio on iOS 4 and have been trying to understand its limitations. From what I can tell...
It is possible to play audio in the background
It is not possible to fire JavaScript events in the background upon track completion
It is possible to fire JavaScript events while the screen is off, but Safari must be in the foreground (before turning the screen off)
My goal for this current project is to create a dynamic playlist that will continue to fire events and move to the next track even while Safari is not in the foreground. Is this possible with the current way HTML5 audio works on iOS?
I am curious about how the chaining of JavaScript events works on iOS if anyone has additional information. It seems that you are allowed to queue back to back sounds, but it must happen shortly after a "human" function happens (for example, tapping an element). Anything else that tries to queue a sound outside of this human function is denied the ability to play.
Also...
Is it even possible to have events that fire to move a real iOS application to the next track? It seems as if the application is only allowed to finish its current audio stream and then it goes into an idle state. Just trying to figure out all the angles here!
This is quite an old question, so I'm not sure if you've found an answer already or not.
One thing I know is that an audio clip cannot be played via JavaScript on mobile Safari.
Autoplay audio files on an iPad with HTML5
The only way to make audio play, is through a click event. This wasn't the case on 3.x, but on 4.x it is. This is because Apple doesn't want the webapp to download audio on a 3g connection programmatically, so they force the user to initiate it.
I would think that if all of the tracks were started downloading (cached), then it may be possible. I would try forcing the user to start one track, and at the same time call .load() on all of the other tracks (in the same click handler). This will force the iOS device to start downloading the audio tracks, and you may be able to play the next track (not sure though).

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