I am trying to implement a directshow based video player as a windowless activex. The plan is to use the player and have it overlaid by html elements.
The problem I am facing is that for the windowless activex to display video properly, the video needs to be painted to a memory DC provided by the container(ie Internet Explorer).
I am trying to write a custom allocator presenter but have not made much progress..
Any pointers on how best this can be achieved?
Related
I would like if it possible to have a mask overlay over the camera using flex mobile framework. I need to develop a cross platform (android/iOS) application using camera on which I want to display buildings. So I know it is possible with native iOS and android code. But I would like to do it with flex mobile.
Do you know if it only possible or not ?
Thansk a lot.
Best regards
Using Adobe Air's camera class, you cannot manipulate the picture this way.
You can change quality, sizing, frame rate etc., but cannot manipulate the image so it will show additional data except data received from the device.
I'm a little confused on the terms. I understand that the spark framework has a video player and a video display. The difference being that video display doesn't have the video controls.
I know that stage video is new in AIR3 and uses hardware acceleration to play videos.
My question is, does videodisplay and videoplayer take advantage of stage video out of the box? Do I need to implement it another way?
After doing some research StageVideo for AIR desktop and extended desktop profiles is not available.
There seems to be an announcement about AIR in the coming days. Hopefully they put this on the road map. Some adobe guys hinted that this is coming.
I don't find any references to it within VideoDisplay and I don't see anything in VideoPlayer regarding StageVideo, plus from reading this article it sounds to me like they would keep them as two completely separate beasts, due to the possibility that the GPU is already in use and therefore can't be used at any given point in time (just what it sounds like to me). http://corlan.org/2010/12/01/working-with-stage-video/
Also when I Ctrl+Shift+T to get to VideoDisplay and VideoPlayer it specifically notes that they aren't optimized for mobile, which it seems is the main purpose for the new class (it's built in to the flash player it seems so I can't access the source).
If you're looking for something with pre-packaged controls and that can take advantage of the new StageVideo, check out the open source media framework (OSMF) says they support it in versions > 1.6. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCUQFjAA&url=http%3A%2F%2Fblogs.adobe.com%2Fosmf%2F2011%2F02%2Fgetting-started-with-stage-video-support-in-osmf-and-strobe-media-playback.html&ei=gbo6T46qKIyXtwedwonzCg&usg=AFQjCNHpm7AV9MZHw79TZjAs_nIZc-qoow&sig2=45WDlwOlB60uMzivf1fZOw
One common hebavior I observed in my slow Internet connection is that most sites on the Web embedding Flash Video, their player is always written in Flex. I can tell by the extremely long loading scroll bar that Flex defaultly provides. From my experience Flash loads faster, Why do people stop writing stuff in Flash anymore?
Are there any fast loading yet rich feature Flash video players>
My experience is that the components provided by default in the Flex framework are more stable than the ones provided in the Flash IDE. So I'd prefer to use the Flex components simply because it means less time debugging problems in the actual component code. It is however true that players based on the Flex framework tend to be heavier in terms of download size. But since video is bandwidth heavy and people who watch video over the net tend to have good bandwidth these days, I guess the conclusions most developers come to is that the extra download size is an acceptable tradeoff for less time spent in coding boilerplate.
Personally, if the requirements state that the player has to load fast and be light weight then I always roll my own in pure AS3 and just implement exactly as much as is needed. But if there is no such requirement, then I'll use the Flex-components as a base and do customization from there.
As for the second part of your question, sorry can't think of any open source fast loading feature rich flash video players right now.
Flex produces a flash movie (swf), so the end result is still flash.
As for the reason behind it, not everybody has or wants Adobe Flash (Studio) or any of the other timeline based studios.
Flex enables anybody to create a flash based application or widget using XML and the free Flex SDK.
There may also aesthetic reasons such as standardised controls.
Try Flowplayer, JW FLV Media Player and the last contender, but not the least from Adobe - Strobe Media Playback http://www.osmf.org/strobe_mediaplayback.html
From my experience Flash loads faster, Why do people stop writing stuff in Flash anymore?
When done correctly, there's no difference in how they work - in fact, I'd argue that stuff done in Flex (specifically, using the Flex SDK) give you more freedom to control how loading is done.
But to answer the question, people stopped using Flash just because there's much better stuff out there. Flex Builder, FlashDevelop, FDT - they're all much better tools for any serious coding and debugging. I used to love the IDE, but now I can't fathom how would anyone do anything serious on it, even when using external code editors.
Flash still works when you need vectors, or to create a library with some embeddable assets, but that's pretty much all it's useful for nowadays.
I am a flex developer, see flex is somewhere flash, here flex has two frames, preloader stage(first frame) and creationComplete stage(second frame), the same frame concept as flash has, but flash has more than two frames and layer concept is also there
Major differneces comnes in the ease of using the components in flex, in flash, altho flash is one of powerful tools that has changes the web,
but flex gives the freedom, i m using flex, so i know that i can give more time on business login development, rather than concentrating on design aspects,
but it's also true, i have to see the design aspects as well in flex,
so happy flexing
I'm working on a standalone Flash application (written using Flex 3/ActionScript 3) that features a text crawl, like what you might see at the bottom of your TV when watching a cable news channel; it's a long narrow box that text moves across from right to left.
I've implemented it by creating a Label element, populating it with text, and then moving it using a mx:Move object with a Linear.easeNone easing function. It works, but it has ample room for improvement. It looks a bit jerky, and tends to have a fair amount of "tearing" (the top and bottom halves of the text sometimes fall out of sync).
I tried throwing math at the problem to get the crawl's movement rate synced with the monitor's refresh rate, but that was a bust. I found out the hard way that the app's frame rate jumps around too much; the "optimized" crawl varied between looking silky smooth and like it had epilepsy.
Is there anything else folks would recommend I try to smooth this thing out? Is there some alternate design you'd recommend I try?
Edit: Some context: the crawl is part of a digital signage application (played from a standalone Flash projector -- no web browser) that does stuff elsewhere on the screen, including video playback and rendering text and images. It definitely gets choppier during video playback, but it's never as smooth as I'd like it to be.
There are two potential solutions to this problem, but both have caveats, the first because of your use of Flex and a standalone projector, the second because it is a mitigator, not a complete solution.
Hardware Acceleration
When publishing your file, you can attempt to have Flash utilize hardware acceleration to alleviate the vertical refresh issue you are running into that is causing tearing. Sadly, Flex Builder 3 is incapable of enabling this setting at the SWF (projector) level (Link to bug). This has yet to be resolved and has been pushed from 4.0 to 4.1 to 4.x... If and when it is resolved, it will likely be a compiler argument in the project settings of Flash Builder 4.
You may be able to determine if this solution works for you by outputting your projector as a standard SWF and embedding it on an HTML document with the wmode set to "direct" or "gpu". Sadly, if it does (it should), you can't use it right now anyway. If you have Flash Builder 4, certain projects are capable of making round trips between FB4 and Flash Professional CS5, though I am not sure what the criteria for that is (my current AIR project has all the project modification menu options grayed out). If you do manage to get your project into Flash, you can enable hardware acceleration in the Publish Settings of the project (File->Publish Settings->Flash tab->Hardware Acceleration option in CS5).
This method is almost a certain solution for your problem, though it has two issues, one already highlighted above, and (for people publishing for the web) that by utilizing direct or GPU rendering on a webpage, you are unable to layer any DOM elements on top of flash.
direct: This mode tries to use the fastest path to screen, or direct path if you will. In most cases it will ignore whatever the browser would want to do to have things like overlapping HTML menus or such work. A typical use case for this mode is video playback. On Windows this mode is using DirectDraw or Direct3D on Vista, on OSX and Linux we are using OpenGL. Fidelity should not be affected when you use this mode.
gpu: This is fully fledged compositing (+some extras) using some functionality of the graphics card. Think of it being similar to what OSX and Vista do for their desktop managers, the content of windows (in flash language that means movie clips) is still rendered using software, but the result is composited using hardware. When possible we also scale video natively in the card. More and more parts of our software rasterizer might move to the GPU over the next few Flash Player versions, this is just a start. On Windows this mode uses Direct3D, on OSX and Linux we are using OpenGL.
**Source*
Direct is the ideal option for this situation, as you can actually have performance degredation with "gpu" as well as visual differences from graphics card to graphics card.
Lower your framerate
The Flash player will continue to play video at its native refresh rate independent of the rest of your project as long as you keep the framerate at or above approximately 2FPS (though I suggest 5FPS minimum). You won't want to run that low for this example, but you are able to lower the framerate of the entire scene without impacting video performance. The closer your framerate is to the screen refresh rate, the more apt you are to actually create the tearing effect unless you are able to absolutely sync with the monitor's refresh rate, which you probably cannot do without the above... Hardware Acceleration.
This problem has existed in the Flash Player for as long as it has been able to move objects horizontally. What happens is that Flash updates a buffered snapshot of the running animation at the same time that the screen is refreshing. If the buffered snapshot changes partway through a screen refresh, you get a tear. This is why lowering the framerate actually reduces the amount of tearing, you are refreshing the buffer less frequently.
As #Tegeril mentioned, using Flex is one of the reasons. Flex is a pretty heavy framework and it does a lot of things behind the scenes. If you're familiar with the life cycle of a component(especially invalidating properties, invalidating the display list, etc.).
As a few minor things that might improve performance:
try to keep a simple display list. If you know the app will always be displayed at one size, then flex won't waste time traversing the display list/tree up to the top and back for measurements. Also, try to use a Canvas. I know, it's not very clean, but since it uses absolute values and doesn't check with the 'parents' much, it should be faster than other containers(like HBox,VBox, etc.)
try to display the video at it's full size(make sure the encoded video dimensions are right so there be any CPU cycles on resizing video
Ok, this was Flex stuff.
It might be very handy to read sencular's article on Asynchronous ActionScript Execution which explains how Flash Player handles updates and renders.
(source: senocular.com)
Frames both execute ActionScript and render the screen
(source: senocular.com)
ActionScript taking a long time to complete delays rendering
I imagine the jerkiness is related to this. Also, I'm guessing you might
get moments of smooth movement then sudden halts, every now and then, when
Flash Player catches it's breath(Garbage Collector cleans up)
Victor Drâmbă article on “Multithreading” in Actionscript might also
be useful.
Soo, to recap:
use Profiler or something and see if the Flex framework is slowing you down, or where the 'bottleneck' is
improve as much as you can on that side then check if it's how Flash Player handles all the actionscript('elastic' frames)
If the bottleneck comes from the Flex framework, worst case, you
can try to minimise the number of components that traverse the display list,
and use pure actionscript for the other things(as #PatrickS suggested, use TweenLite, etc.)
If it helps, try to preload data(fetch rss feed and all that) at the start, and when you've got most of the important bits that don't require 'refreshes'/loads frequently, display the app. You will use more memory, but will have more cpu cycles to spare for other tasks.
Also, if it's display objects that are the 'bottleneck' and there's plenty of them, check if you can reuse them using Object Pools.
HTH
TweenMax or even TweenLite ( http://www.greensock.com )handles this sort of job pretty well. What else is your app doing while the text is scrolling though? Is it possible that some other processes are interfering?
This may not be helpful, but have you considered putting the crawling text into the html DOM and using CSS transitions to crawl the text. Obviously there's the IE problem, but it should be supported in IE9 and you could use javascript as a fallback.
This may seem silly, but CSS transitions are getting hardware acceleration and separate processes for plugins meaning on a multicore machine you could get parallel threads.
One thing you might consider is to move your label incrementally using a Timer instead of an easing function. That way you can take advantage of the updateAfterEvent method to get smoother rendering. Here's a link to an article/video from Chet Haase (Adobe's Flex graphics dude) that explains usage along with an example app with code:
http://graphics-geek.blogspot.com/2010/04/video-event-performance-in-flex.html
Hope that helps.
let's say i want to play an mp3 song in the background of the website alog the user's travesal between the different pages...
is is possible?
I would not recommend doing this, it will annoy users and possibly alienate your users without sound. The easiest way is to have another frame play the music. Another way is to have a popup come up and play the music [which stays up between pages].
Within a single frameless page? I can't think of any possible straightforward solution.
Off my head, the altenatives are:
1. frames (parent frame plays the audio, child frame holds the site pages)
2. pop-up window which plays the audio
3. a single page which puts in page content via ajax and loads into the main container while the audio is played outside the container
4. use flash and puts in content via actionscript into the flash display panel
Personally, I would not recommend any of the above :P
Multimedia is the best way to enhance the user interface of any application. In .NET there is many ways to play an Audio using any .NET technology supporting languages. One of the simple way to acheive is Multimedia Control Interface, shirtly we call it as MCI, wrapping high-level system components, such as Windows Media Player to play our audio files.
visit this link.. to get more information.. about it
http://vivekthangaswamy.blogspot.com/2006/11/using-cnet-play-multimedia-files-using.html