Android video.duration does not load until video.play() - javascript

I have an html5 video which I am trying to set up callbacks at certain intervals during playback. The video starts playing from javascript with video.play(). Right now my code listens for the 'loadedmetadata' event, then queries the duration and sets up those callbacks. Works fine on mobile safari, but not on Android (2.3.4 and 2.3.7).
On Android, 'loadedmetadata' seems to be emitted before the duration is actually available. To test this, I logged the duration at every step of the loading process in my code to see where it can actually be read. Until video.play() and after one 'timeupdate' event, the video.duration property is 6000, regardless of the video being used. I tested this with an mp4 file and a 3gp file. Once those conditions are met, the actual duration is available.
I found this other post with similar issues [1]. The highest voted answer that wasn't accepted is how I originally set this up, and it works fine on iOS. The accepted answer also does not work, and suggests this is a webkit issue. I log the video.readyState property and see that it is '4' before the video starts playing, but the duration is still not available until after it starts playing, and the first 'timeupdate' event.
Our current workaround is querying the video.duration value, and only setting up the event callbacks when video.duration !== 6000. This is pretty ugly and I'd like to get to the bottom of it, lest this hack come back to bite. A discussion here [2] seemed to suggest that the issue may be related to encoding. That is, not encoded properly, android doesn't read the metadata correctly until the file is loaded, or perhaps at all and it calculates the duration another way.
Is there anything I can do to make this cleaner, or am I stuck with the hack for now?
[1] Problem retrieving HTML5 video duration
[2] http://www.broken-links.com/2010/07/08/making-html5-video-work-on-android-phones/

Id use a setTimeout which calls a function to check whether the duration is available recursively.
This way the function can as soon as any information is available, display etc. the duration.

Related

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.

Audio is unable to play via javascript on some mobile browsers

I'm trying to do a simple thing. I want some audio to play exactly after 10 seconds when the user enters the webpage. I used the following code
var aud=new Audio("someAudio.mp3");
$(document).ready(function(){
setTimeout(function(){aud.play()}, 10000);
});
It is working perfectly fine on desktop browsers. However, the audio is not playing in some mobile browsers like Google Chrome though it is working in Firefox. What may be the possible reason for this and how to fix it? I saw some similar questions but didn't find a suitable answer.
Thanks in advance
I'm trying to do a simple thing. I want some audio to play exactly after 10 seconds when the user enters the webpage.
You can't unless there has been user interaction.
Handle a click event for some element. In that event handler, play some other audio. (This audio can be silent!) After 10 seconds have passed from load, if the user has touched/clicked something, and you've done this, you should be able to play your audio file.

Akamai Media Player: Get event callback when it's ready to play

I'm using the Akamai Media Player to stream video for an event. Normally the video stream starts the the "LIVE" position, but I would like mine to default to an earlier point in the video stream so that when users come to my page they always see something cool to start instead of the empty event grounds when the event isn't actively happening.
I'm trying to find a way to receive a callback when the video player is ready to go so I can tell it to seek back to the right number of seconds. The documentation says there is a 'loadeddata' callback, but for the life of me I can't get it to work. I'm never receiving any notifications. I can just set up a javascript timeout for 1.5 seconds that will cause it to seek back to the right time, but then I create a race condition and if the flash player (akamai player) hasn't properly loaded at that point it still won't work.
Documentation for the Media Player: http://videotest.esmas.com.mx/avp/userGuide/AkamaiPlayer_UserGuide.pdf
Any suggestions?

Mute YouTube sound in Delphi TWebBrowser

I'm coding a small Video Previewing tool in Delphi 2010, but I want to mute the videos programmatically, because as I said, it's for previews.
I've tried several versions of this code, but it always results in a script error, and in the end it's unable to do it.
WebBrowser1.ControlInterface.Document.QueryInterface(IHtmlDocument2, doc);
doc.parentWindow.execScript( 'document.getElementById("movie_player").mute()', 'javascript' );
Also tried to wait a little longer for the control to complete browsing, but still nothing.
Try to call your code in TWebBrowser's OnDocumentComplete event. This event is fired when the document inside is fully loaded, so the object, if it's expected to be there, is already downloaded and is present. Without showing of your JavaScript code I can't tell you more.
But I would do it differently. I would implement code like this one directly into your navigated web page. It can mute the sound immediately in the onYouTubePlayerReady event handler what means immediately when the YouTube player is fully loaded. It's better than call the function later on because it may produce a short sound burst because of some delay between the TWebBrowser's navigation completion and execution of your code.
reference to youtube API's http://code.google.com/apis/youtube/js_api_reference.html
I believe that at the time you're trying to mute the video, the "document.getElementById("movie_player")" fails.
try to call it like setTimeout( 'document.getElementById("movie_player")', 10000 ); where 10000 is 10 seconds, or even longer, probably the player needs a couple of seconds to be downloaded.
I would also give it a try in different browsers to see if it's actually something that doesn't work as expected in TWebBrowser.
EDIT
I would also give "VLC" a go, it can play swf files locally and remotely, there are interfaces for the VLC libraries, so why not? (:

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