Silverlight MediaElement reads content to the end before playing - silverlight-4.0

I am working on a silverlight 4 project, where the goal is to play back video from files on the local PC (these files are downloaded first, and then played).
The problem I am having is that for relatively large video files (i.e. 350 MB+), the media element 'hangs' for about 8-10 seconds once the source has been set. From what I have read, the MediaElement is reading the content to the end of the file before it is loaded. There seems to be no event for when the mediaElement is in the "Opening" state - only "Opened". The delay seems to be between setting the source of the media element and the media element hitting the "Opened" state.
Is there a way I can work around this? At the very least is there a way that I can prevent the mediaelement from hanging the application while it loads?

I put the SetSource into a background worker and then called BeginInvoke on the UI dispatcher and it seems to have done the trick. Was calling the wrong Invoke method.

Related

HLS Player: Clear video.js buffer on click

I have two live videos feeding an encoder which creates H.264 chunk files and an HLS manifest which is being served by an apache web server.
A browser page using video.js shows a player. Pressing "play" on the browser properly plays the video. It works well.
However, if we change video sources (by flipping the switch in the picture below), there is a considerable delay (10 seconds) before the new content is displayed in the player. I'd like to get that to 3 seconds.
It appears that video.js and/or the HTML5 player in browser is buffering that amount of content. (if you delete the files on the web server, kill apache, or even pull the ethernet cable, the video keeps on playing!)
A button on the web page controls the switch. When clicked, I would also like to clear or reset the player so that it immediately re-reads the index.m3u8 manifest and downloads the new chunks.
So far, haven't found anything promising searching the internet or in the video.js API docs. There are lots of articles on API calls for fetching the current buffer percentage but cannot find any API for clearing it altogether.
Any ideas?
The encoder is set for 3 second chunks and the playlist depth is set for 10 entries.
I had a similar problem. Since i could not find a reliable API for this, i came up with a rather dirty workaround to clear the buffer:
var ctime = player.currentTime();
player.currentTime(0);
player.currentTime(ctime);
This currently works for me in all major browsers.

Force PreloadJS to use XHR for all loading

I'm using PreloadJS as part of an application that's being built with the CreateJS libraries. PreloadJS is being used to pull in graphics and audio files listed in a manifest. I've setup a progress bar and hooked the preloader's fileprogress and fileload events to update it. I'm getting progress updates as the images load, so I can see the progress bar crawling along, but I never get fileprogress updates for the audio files, just the fileload (file is completely loaded) so the progress bar sits idle and then suddenly jumps to 100%. Since the audio files are by far the largest assets, this creates something of a problem as far as providing meaningful load progress to the user.
I've looked at the documentation for PreloadJS and it indicates that XHR loading is the preferred method because it does provide the progress updates, but that PreloadJS can fall back on things like tag-based (<audio>) loading of audio files.
None of the file loading is local or cross domain, so it would seem to me that PreloadJS ought to be using XHR.
Is there a way to force PreloadJS to use XHR for everything so I can get consistent progress updates or why would I not be getting progress events for these much larger files?
I believe there are open bugs in PreloadJS and SoundJS which prevent audio loading from reporting progress. I have logged issues for both libraries:
https://github.com/CreateJS/PreloadJS/issues/99
https://github.com/CreateJS/SoundJS/issues/119
Some additional info:
Although PreloadJS will try and favor XHR-based loading for filetypes it controls, audio loading works a little differently.
SoundJS actually injects the functionality into PreloadJS to handle loading, and will not respect the useXHR parameter, instead relying on the browser capabilities (and SoundJS plugins) to load and play audio. Unfortunately, web audio requires an array buffer (loaded with XHR), whereas HTML audio requires HTML tags, so the playback capabilities dictate how audio files load.
By default, SoundJS will default to load/use the following plugins in order:
WebAudio (therefore XHR)
HTML (therefore tag-loading)
This should favor XHR-loading and webaudio for most browsers (IE is the standout that will almost always require HTML loading). You can force plugin order by registering the plugins manually before you begin playback/
Thanks for the surfacing this!
#Lanny is correct, there are open bugs for this issue. Currently SoundJS is setup in a way that always uses Tag loading with PreloadJS, even when using WebAudio which loads via xhr. The result is that regardless of plugin, there is currently no way to get progress events.
The good news is that we are currently in the process of revising how loading works between PreloadJS and SoundJS and this issue should be resolved.

How to play sound from resources using windows media player?

I am making a game, so at one point I need to play two sounds at once, so I played the first one using the "My.Computer.Audio.Play()" Method to load from resources.
As for the second, I used Windows Media Player to load the second sound In A SPECIFIC FOLDER, now I know it is possible to extract files to a folder and program it to play from there to avoid trouble, but I don't want them to be extracted.
So I'm trying to get the file path from resources and put it in WMP's URL, but couldn't get any result after searching the internet.
Am I missing something?
And if you know any better alternative, make sure it can:
1- Replay sound (coding with timer is ok),
2- Change Sound Position
You can use the MediaPlayer class in code or MediaElement in XAML for playing audio files in a WPF application. Check out the article WPF Media Player In VB.NET for code samples.

Application getting slower and slower when navigating

I'm building a Windows Phone application that does video capture in a page and has a custom player in another page. I'm using my own custom codec so the player needs a lot of DispatcherTimer to keep track of several behaviors on the UI part and serve the movie at the good framerate in the codec part.
I'm trying to release all DispatcherTimer as I know they are CPU intensive, but even when stopping them my app is still very slow. If I press back-back then follow the flow, the speed divides by two each time. If I don't use my player, eveything is ok. And my player is only made of 3 DispatcherTimer, a FileStream and an Image box.
I feel that DispatcherTimer are still running in memory and are double-instantiated even if they are instantiated as private on the page directly.
Can I force the page to release all this stuff?
Actually I don't understand yet what is the difference between navigating to a page next to current page, or navigating back. I don't know i.e. how the page is shown again without calling InitializeComponents, so I'm mixed up about which resources to release, and which resources to keep intact.
My execution speed problem was really caused by some running DispatcherTimer, so I'll answer it to have it archived.
The solution:
Ensuring that all DispatcherTimer has been instantiated directly on the page so that we can nullify them from anywhere in the code.
In OnNavigatedFrom, I kill the DispatcherTimer and in OnNavigatedTo, I recreate them with myDispatcherX = new DispatcherTimer();
No "temporary" timers, like "DispatcherTimer myTempTimer = new DispatcherTimer; with ((DispatcherTimer)send).Stop() in callback, as chances are that it remains in memory in an application where we navigate.

Generating a random preview image on a HTML5 video tag

Is it possible to capture a snapshot of a video that's loaded using the HTML5 video element and use that as a preview image until the video loads or the play event is triggered? I know about the poster attribute but I want the thumbnail to be self generated, like a random frame from the video. Sort of what YouTube/Vimeo does.
Thanks,
I don't think that this is possible in pure HTML5. Principally because the stream is not loaded when you see the 'object' in the webpage so the client can't get the desired frame.
However, the best option for you is to save / cache the 'random frame' before loading the page and then use it as the poster of the video. This will allow you to reduce the client work and save the bandwith.
check THIS, which is the first thing that I've found (if you're using PHP and you want a 'quick and dirty' way to get the frame)
Update
Apparently HERE there is a solution with popcorn.js BUT it seems that you can't do it in the way that (I suppose) you need.
This because it would be possible to do this only inside the same domain due to browser security issues.