Cause of flv corruption in AIR output? - actionscript-3

I have a fairly complex AIR project which is compiling a lot of movieclips together using timelinemax and finally outputting the whole thing as an .flv using https://github.com/zeropointnine/leelib/tree/master/src/leelib/util/flvEncoder
I am getting corruption of the flv when certain videos are added to the timeline (all videos are embedded in movieclips in an external .swc). Here's what the corruption looks like:
It looks as if the second video I add is being somehow combined with the first and going all crazy. But the two movieclips containing these videos are never on the stage at the same time, they are added one by one when their part of the main timeline is reached, and removed afterwards. This works in all other cases, and the corruption does not happen with certain videos. I am creating all the flvs for embedding myself, in After Effects, and exporting them all with identical settings.
Can anyone shed any light on what might be causing this? Sorry not to post any code, but there is just so much, I wouldn't know where to start, and I feel like this probably isn't a code problem?
Thanks!

Well, the answer seems to be: don't load in video files from an external .swc. I moved all the movieclips containing video into my main .flv and the corruption is gone. I don't understand it, but I'll take it.

Related

In AS3, how can I dynamically load and unload sequential SWF animations to the stage seamlessly?

I am working on a project that will have the user seeming to fly in 3D from point to point in an architectural model, based on choices. It is a tree-flow, with everything starting from one point and branching out from there, and it only needs to animate in one direction, which makes things easier.
The thing is that the animations from place to place are C4D animations rendered as PNG sequences, and in total they will be VERY large, so I want to package each segment as an individual SWF and load and unload them dynamically as needed.
I expect the first thing to do will be to see if I can have my upstream guy render them as JPG sequences instead... is that a good idea performance-wise? I imagine it will be in terms of bandwidth.
The main question, however, is how I can dynamically load one of these sequences, have it play and stop on its final frame (over which data and choices will display), and then - based on the user's selection - load and play the next animation seamlessly from the first, without endlessly stacking up loaded clips. When the user goes back a level, I only need to jump to the first frame of the animation, but going forward always involves a smooth flight.
I suspect the solution may have to do with adding, say, to the loader by specific names, then as we transition out, load the next one with a specific name, and then unloadChild() and do whatever other kind of garbage collection I need to do to purge from memory entirely. I want to be as cognizant of memory usage and performance as I can, because at certain spots there will be other images and videos loaded on top of the flight animations.
Does anyone have any ideas about this? I'm sure it's a common need, I've just never done it before, and I want to do this as timeline-free as possible.
Thanks in advance for any advice!
Mattynabib

Flash .exe projector on a cd, memory issues

I'm working with a project where we are running a projector from/on a CD, and this can't be changed, to run an e-learning program of sorts. Everything is included on the CD and it doesn't need anything else to run, ie all imgs and xml and whatnot is on the CD.
The problem is that on some computers, assumedly less powerful ones, the entire process clogs up and instead of showing the images just white blank areas appear. The imgs used have been downgraded to a lower resolution, from 1333x1000 to 800x600, and this has solved the problem from what we've found so far.
My question is, does anyone know of any other way to solve this without cutting down the img quality?
As it is right now all the pics (about 180 i think) are being loaded right when the process starts and one idea i have is that you load the pics gradually as needed, 2-3 in advance back and forward or maybe an entire chapter even (7 chapters with imgs are used), to always ensure smooth tweens without having to wait for loading.
But as I've read that there seems to be some memory issue when using a flash projector on a CD/DVD, I'd also like to get more details on what the actual problem is and if possible to find more solutions to it.
I found some links that were supposed to target Adobes own views on the problem, but these links were obsolete. (links found here http://www.flashjester.com/?section=faq&cPath=14_23#394).
Any ideas, help, links, tutorials and what not are welcome.
Yeah, you need to load your assets on-demand and be careful about references so unused things are really garbage collected when they aren't needed anymore.
If you are really running from a projector, then load times aren't totally a concern. Assets form the local filesystem are always available the next frame; they aren't streamed from the disk like from the network. However, bigs file or ones with lots of exports may end up with a longer frame time, or a noticeable delay.
You also need profile things to see if your changes are actually doing anything. Poke through the flash.system.System class to see how you can get info, or take a look at SWFProfiler.

Is it possible to generate thumbnail from a flv using as3?

Is it possible to generate multiple thumbnails from a FLV using only as3? The flv is on the same server as the swf so I'm not using any dedicated streaming server. I'd imagine that as long as the flv has load the video you'd be able to pull bitmapdata from a specific time of the flv.
My idea is to pull around 8 images from every flv, convert them to buttons and use them as links to specific chapters in the flv.
If this is not possible, would it work better with a dedicated streaming server like red5?
Edit:
I'd also like to know how to do it if it's possible :)
The idea is to not use the server.
The thumbnails will only be used within the swif, so no saving to another location.
You can do this in AS3 as long as you're actually playing the video within Flash. While playing when you seek to the desired frame capture a bitmap. If you want to save the bitmap for later use you need server-side code to store it.
Streaming vs http download will not make this problem any easier or harder (although with a streaming server you can seek to the desired point without having to download the whole flv to that point).
This would be much better done on the server. You'll need an app that can extract an image from an FLV. ffmpeg can do it.
I know it is possible to get mplayer to output stills from an FLV (though might need a bit of fiddling to get the time reference right), and these in turn can be stuffed into ImageMagick to resize into thumbnails. Not best solution, but probably easier than digging around as3's API.
video thumbnailer is a good idea.
http://blog.chrometaphore.com/2010/03/26/how-to-create-video-thumbnails-runtime-in-pure-actionscript-3-0-videothumbnailer/

Multiple Flash objects on a single web page?

Is there any significant performance/load time impact if single web page will load, say, 10 identical flash objects? 20? 30?.. any evidential data on sustainability of such kind of setup?
This would be the same flash app, each instance serving its own stream.
There's definitely going to be some overhead in size as there is a certain amount of code that is contained in every swf regardless of it's developer created content.
I'm almost certain there would be speed issues as well, which would see frame rates drop right down the more swfs you add to the page.
To be honest the concept smells a little fishy and i would think there must be a better solution to your problem.
EDIT
Also there is a restriction on having two steams coming over http per domain. Sure you could get around this but it will definitely be an issue.
I found this post which might help. The trick is to use SWFObject to embed your swf files.
I ran into a strange problem today. On the music charts page on Muziboo, I was displaying a list of songs and a playlist on the right. Each song has a small button player done in OpenLaszlo. In firefox everything was fine and in IE (not unusually), the page would freeze for sometime. This would happen once and repeat only if I delete cache and try again. I googled a bit and learnt that it's a good idea to embed give each swf a unique id otherwise the browser misbehaves. I then went ahead and used swfobject to embed the swf files and everything started working great!
Yes, it'll likely nuke the browser if you go too far down that road.
If you want to deal in multiple streams, perhaps combining all your would-be applets into one giant one might work better. It'll certainly offset the serious overhead you'd have with 10-40 of the little blighters.
If this is a music player, you want to have a serious look at doing some JavaScript remoting. It's fairly trivial to control a flash app via JS so you could have standard HTML/CSS controls without having to load up a billion flash instances.
Design-wise this just sounds like a bad idea. You'd be running multiple instances of the Flash player inside a browser, each of which has an individual cost, and the host (in this case the browser) will run all of them on the same thread (with the exception of certain elective asynchronous processes), so you're almost surely going to run into problems of various kinds -- jittery playback, UI blocking, processor burden, memory bloat, consequent instability of the host, etc.
Unless the SWFs are very tiny, and doing very little work, it seems like a design that's just asking for trouble. Indeed you could test such a thing fairly easily; have you run any tests yet? Just curious.
Also curious as to the requirements; we might be able to offer more constructive alternatives if we knew a little more about what you were aiming for. Have you considered simply loading all the SWFs into a single container SWF requiring only a single browser-hosted instance of the Flash player?

simple music or tunes via HTML?

I'm looking for a simple way to put up musical "tunes" on a website.
So here's an analogy to explain my question:
Let's say I want to put up a couple of big triangles as a picture on my web page. I can either draw a bitmap and save as GIF/JPG/PNG, put it up somewhere on the internet, and link to it with an element. That works but the larger the picture the more space my image file takes up.
Alternatively, I can use SVG (even though Internet Explorer support is lacking, grr) and use vector graphics which uses very little bandwidth regardless of image size.
In the music world, I can use WAV or MP3 files. Works great -- but if I just want to publish a 1-minute song of simple notes, by knowing the durations & pitches, & don't care that it sounds 100% exactly like a piano or accordion, is there a way to (a) create a file with the song, and (b) put it online in a format that is space-efficient? 1 minute of MP3 usually takes up hundreds of kilobytes.
You could use a MIDI file, this stores durations/pitches etc. as you suggest. You should be able to easily find software to create this type of file. However you will probably find the results sound terrible, as it is very dependent on the synthesiser hardware/software that is available on the end-user's machine.
For what you need this might be reasonable though.
Look into playing music files on websites using Flash.
You can control the Flash through JavaScript calls.
This is currently the "recommended" way to play small audio clips in a website.
For larger media files, look into streaming FLV files using a Flash player.
Hope this helps :)
Check out the MIDI format for instruments.
http://en.wikipedia.org/wiki/MIDI