art, life and software development

One way to improve server code performance in Flash Media Server is to compile it as Bytecode. I really do not bother much about protecting code as, I feel it is the generousity of others who have not protected their code that has brought me thus far. Having said that it is also a good way to protect your server code if you so desire form peering eyes. In addition you can also archive your server code in the situation where you have more than one script managing the logic on the server. The tool to do this is the FAR executable, a compiler that comes with the FMS install. This tool gives you the options of compiling your *.asc files to *.ase bytecode and your files *.asc or *.ase into an archive that FMS interpretes. This archive is a *.far.
The method I detail below works in the Linux environment - If you use Windows the difference in syntax is nominal

1. Find the FAR executable, in Linux it is in the install folder. An easier way to get it is to untar the FMS package and look inside the root folder.
2. Place the FAR inside the folder of the scripts you want to compile
3. Open a Terminal and 'cd' to the directory.
 ayo@W34PON-X:~/IDE/Tools$ ./far
4. Compile your *asc file into a *.ase file
ayo@W34PON-X:~/IDE/Tools$ ./far -compile ./getbytes.asc
This compiles getbytes.asc into getbytes.ase
5. Deploy the *.ase file to the application on FMS instead of *.asc

The Adobe Open Source Media Framework is a rich media scaffolding designed to create a unified platform for the deployment of rich media on the web. It is based on the Open Video Player codebase an earlier code-base developed and designed to extend the Adobe rich-media codebase and improve the tools available to the rich media developer. The OSFM brings a unique point of view to rich media development in that it encapsulates the media deployment elements (video, audio and images) into one interface that can be accessed and changed at runtime depending on the asset to be deployed. It is delightful to work with, however in its current iteration, version 0.4 there are lots of features lacking or not working properly. Developers are well adviced not to look to this release as a product development framework but, as a work in progress that will definitely change. Having said that, its unique development viewpoint makes it a future winner in the development of rich media players and such other rich media development vehicles.

Although technical and deployment information is sketchy at best there is a reasonable swathe of it online if you Google OSFM to give you some background of the framework. This blog- post will focus on explaining the technical virtues of the framework, showing the current pitfalls of the framwork (from the blog writers point of view) and looking at code to build a video player that utilises HTTP and RTMP as the deployment protocol.

The OSMF looks at 3 separate elements in order to compose the visual experience. These elements are namely the, Media elements, Media composition and the Media configuration.

• Media elements are the actual media types - videos(flv, f4v ...), audio (mp3, mp4 ...) and images(jpg, png)
• Media compositions are the media elements as in the video, audio and image deployment classes and their spacial and compositional relationships
• Media configurations consist of their spatial regions, their behaviours (called Traits), and how you configure and arrange them (overlays and such).

In order to pull off this saparation of responsibilities, the OSMF has 3 main classes, the MediaElement, the interface IMediaTrait and the CompositionElement

• The MediaElement is the rich media deployment vehicle. Thic class is based on the Open VideoPlayer codebase. In the OSFM classes its code can be found in the package com.adobe.strobe.players. The class is MediaPlayerWrapper.as. This is the Flex version (I have not tried the Flash CS4 version - though I'm sure its a facsimile of sorts). The MediaElement may be a simple video delpoyment or a collection of media experiences e.g pre-roll video, main video and post-roll video. The MediaElement has subclasses like the VideoElement and the AudioElement that allow you to programme to an interface rather than a concrete implementation.
• The IMediaTrait holds the various behaviours for the target media being deployed. Traits are of different types. The behaviours for the IViewable trait for instance are for media that is visual like video and images. For the IPlayable interface its for media that is playable like videos and audio files. In effect an audio element would have IPlayable, IAudible and ITemporal (time based) traits. In the case of non visible or audible traits there are the ILoadable traits - dealing with NetConnections and NetStreams and their accoutrement.
• The CompositeElement is the mixer allowing you to compose your media. Two main calsses that stand out here are the SerialElement and the ParallelElement that allow you to choreograph the deployment of your media.

This is a basic overview of the framework. Now lets look at a basic video player deployment. I have put in no controls playbutton and so on. This player will just auto play but it gives you the general jist of the matter. The application is coded in AXDT with the Gumbo SDK. The OS is Ubuntu 9.04 and the IDE is Eclipse Galileo.


Please Note: In order to stream from Flash Media Server, you need to put the Application.xml file inside the streaming application folder look for the < StreamManager > tag and add
<VirtualDirectory><Streams>/C:\lalalalala </Streams> </VirtualDirectory>. If you do not do this it will not stream. In the alternative stream from the VOD application
In addition the useInstance boolean for the FMSURL does not work so you cannot stream with the default instance based URI. Your URI must have the full path e.g application/streams/instancefolder/stream where application is the application folder in the FMS applications folder

ActionScript 3.0

/**
* @author ayo
* @description: Understanding the Adobe Open Source Media Framework
*
*/

package net.designstreet.media
{

import com.adobe.strobe.players.MediaPlayerWrapper;
import flash.events.Event;
import mx.containers.Canvas;
import mx.core.UIComponent;
import org.openvideoplayer.display.MediaPlayerSprite;
import org.openvideoplayer.display.ScaleMode;
import org.openvideoplayer.events.*;
import org.openvideoplayer.image.ImageElement;
import org.openvideoplayer.image.ImageLoader;
import org.openvideoplayer.media.MediaElement;
import org.openvideoplayer.media.MediaPlayer;
import org.openvideoplayer.media.MediaPlayerState;
import org.openvideoplayer.media.URLResource;
import org.openvideoplayer.net.NetLoader;
import org.openvideoplayer.traits.*;
import org.openvideoplayer.traits.ILoadable;
import org.openvideoplayer.traits.LoadState;
import org.openvideoplayer.traits.MediaTraitType;
import org.openvideoplayer.utils.FMSURL;
import org.openvideoplayer.utils.URL;
import org.openvideoplayer.version.Version;
import org.openvideoplayer.video.*;
import org.openvideoplayer.video.VideoElement;


public class DSt_OSMF_Player extends Canvas
{

//private static const REMOTE_IMAGE0:String = "http://www.adobe.com/ubi/globalnav/include/adobe-lq.png";
private static const REMOTE_STREAM:String = "rtmp://myserver/clearwater/darkwater/wolverine";
//private static const REMOTE_IMAGE1:String = "http://www.adobe.com/ubi/globalnav/include/adobe-lq.png";

private var _strobeplayer:MediaPlayerWrapper;

/**
*
*
*
*/
public function DSt_OSMF_Player()
{
assemble();
}


/**
* Play media
*/
public function playStrobe():void
{
var melement:MediaElement = null;
melement = new VideoElement(new NetLoader(), new URLResource(new FMSURL(REMOTE_STREAM, true)));
_strobeplayer.element = melement;
//
}

/*
* Assemble the player bits
*/
private function assemble():void
{
_strobeplayer = new MediaPlayerWrapper() ;
_strobeplayer.width = 640;
_strobeplayer.height = 360;
addChild(_strobeplayer);
_strobeplayer.scaleMode = ScaleMode.LETTERBOX;
_strobeplayer.autoPlay = true;
playStrobe()
}
}

}

MXML

< ?xml version="1.0" encoding="utf-8"? >
< mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:dst="net.designstreet.media.*"
layout="vertical"
>
<mx:Script>
<![CDATA[

]]>
</mx:Script>
<dst:DSt_OSMF__Player id="dstplayer"
top ="10"
left ="0"
bottom ="0"
right ="0" />


</mx:Application>

Main Application

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:dst="net.designstreet.media.*"
layout="vertical"
>
<mx:Script>
<![CDATA[

]]>
</mx:Script>
<dst:DSt_OSMF__Player id="dstplayer"
top ="10"
left ="0"
bottom ="0"
right ="0" />


</mx:Application>

Thats it!

To use the FLVStreamer tool to extract an RTMP stream you need to know the rtmp address of the target stream. Once you have that change directory to the install directory of the FLVStreamer and write the following commands:

$ ./flvstreamer-1.7_ubuntu_jackalope -r 'rtmp://[IP address or host name]: [port]/river/alpha/sample1.f4v' -o testdump.f4v

It was delightful to see that the utility could also retrieve *.f4v files. I guess this means that any H264 encoded file is extractable
. The same commands work for the rtmpdump tool.

In January "Adobe announced plans to publish the Real-Time Messaging Protocol specification, which is designed for high-performance transmission of audio, video, and data between Adobe Flash Platform technologies. This move that has followed the opening of the AMF spec has been received with varying degrees of enthusiasm from the RIA community." Unfortunately for Adobe this proclaimation has come round to bite them rather painfully in the wotsits.

The problem is a tool called rtmpdump. Adobe has had to issue a DMCA removal request for rtmpdump on Sourceforge. This utility is apparently at the heart of the IPlayer desktop I was praising so fervently a few posts ago - I must confess I have not authenticated that bit of information so it may be completely incorrect - quote me not. Rtmpdump acts by presenting itself to the rtmp streaming server as the client *.swf. As a result it is able to poach rtmp stream data from the server and make it accessible for download. In itself this was not that much of a problem however, rtmpdump it seems can also extract RTMPE protected files. This is the source for Adobe's concern and mine actually (I hate setting up the framework for RTMPS and RTMPE was an easier more accessible fix - obviously no longer).
I have been told by one of this blog's readers lkcl that rtmpdump implements the SWFverification schema. My warmest thanks.

Fabio Sonnati explains it thus:
"rtmpdump acted mainly as a Flash Player emulator as it mimics the rtmp(e) protocol from handshaking to encrypted streaming.
Acting as the specific SWF (thanks to SWFverification hack), Rtmpdump was able to substitute the original SWF, connect to FMS and grab the protected RTMP(E) stream."

It does seem then that Adobe feels that rtmpdump "can be used to download copyrighted works". Apparently certain Channel4 content that was supposedly rtmpe protected has already been poached by the usage of this utility.

Sourceforge has taken down rtmpdump from its site. The furore has exposed a whole gang of rtmp ripping tools. For starters there is a non-rtmpe version now renamed flvstreamer. It will do all that rtmpdump does without the support for rtmpe ripping. Then there is the get_iPlayer tool a utility providing access to the BBC IPlayer content. I do not see how that helps much though as the BBC IPlayer desktop provided the same functionality. So except stolen fruit tastes sweeter there's really no point in that. In addition the source code of rtmpdump v1.6, with the get_iplayer application removed is available here.

Adobe has just released an update for the new FLVPlayback component. The component is a more stable offering providing support for Dynamic Streaming (multibitrate) and DVR. Adobe has also released the new DVRCast application that makes it easy to add DVR-enabled live streams to your website using Flash Media Server 3.5. Both tools can be downloaded from http://www.adobe.com/go/fms_tools/. I will be putting up my experiments with the new FLVPlayback soon.

Over the last few years I have been developing and streamlining an MVC scaffold for use in my projects for MagicLantern. One of the goals of this scaffold was to provide support in the Model so I could immediately use it for Flash Media Server development without going through all the set up motions. It also had to be flexible enough to allow for easy modification by sub-classes of the Model. Highest on the list of goals though was that it had to be accessible to any developer with an understanding of MVC - no trying to learn about plugin interfaces and facades, just setup and use. I think I have arrived there with MagicMVC. It is the scaffold on which this prototype of a multiuser video chat application in Papervision3D is built.

It works nicely so far, the Model can be extended by a subclass to facillitate developer specific classes, but all that is generally needed is for the Wrapper class to send the FMIS URI to the model / subclassed model when the model is instantiated and the rest is up to the developer to do as they please. This prototype is a bit buggy as it is still in development, but it works well. Please use headphones and a microphone and PLEASE make sure you have a camera.

As a Flash Media Server developer I come across the occasional file that refuses to stream or playback. This usually leads to guess work, a bit of trial and error and then the formulation of various hypothesis as to why the file failed. Sometimes that explanation is not enough for the client or video producer who will swear that their video production tool is top notch and that the developer is the clueless one.
Thanks to Adobe and a nifty little command line utility, that bridge has now been crossed. "The FLVCheck tool can be used to analyze FLV files before they are deployed on Flash Media Server. In addition, the tool can also add or update metadata to reflect file duration correctly. The tool verifies that metadata is readable, specifies an accurate duration, and checks that the FLV file is seekable by Flash Media Server. The tool supports unicode filenames".
(FMIS Admin Guide)

The use case I am describing here is for Linux specifically Ubuntu/Studio 9,04 Jaunty however I believe the same procedure applied to Windows.

• Download the tool from HERE

• Unpack it to a folder of your choice.

• Open Terminal (or command prompt), and change directory to the folder you unpacked the tool. On my computer that was the command:

cd '/media/disk/INTERACtIVE/UTILITIES/FLVChecklinux'

To do a basic check of the video, the following is the format. Please note the command may vary in Windows:

./flvcheck [-option] <file ...>

In my case it was:

./flvcheck -f '/media/disk/MEDIA/VIDEO/Adding_a_Launchpad_PPA_s_key_to_Ubuntu.flv''

This was my feedback:

09-05-20 14:29:25 /media/disk/MEDIA/VIDEO/Adding_a_Launchpad_PPA_s_key_to_Ubuntu.flv passed

Adobe provides a list of FLVCheck errors, please take a look at the documentation to identify your unique error

In spite of years of Flash Media Server development, there are still quirks of the system that cause a great deal of head-scratching. Primarily for my own benefit, I have decided to list the oddities of FMIS development, what works, what doesn't and workarounds if they exist. If you have come across any yourself feel free to send them in so the list can be updated.

Streaming: What works

• To get the end of a streamed file when using the VideoDisplay control(Flex) or the FLVPlayback component (Flash) use the VideoEvent.COMPLETE. vid.addEventListener(VideoEvent.COMPLETE, videoEventHandler)

Server Administrator

• AllowDebug: Setting the < allowDebug > in your Application.xml or in your main/< application name >.asc, does not guarantee your ability to view Shared Object data in the admin panel. It is very temperamental and more prone to refuse view than allow. Debugging streams works a lot better.