Frameserving

Frameserving is a technique with which you feed a video signal frame by frame from one application to another. It was very popular when video editing programs did not yet include an encoder to create an MPEG directly from the timeline. It is now less popular, but can still be very useful.

1. General principle

The principle of frameserving is basically very simple: video (and audio) is directly transferred from one application to another without the need to create a file that contains the video data. When a command in the source application is given to start a frameserving process it will create a file to which the frames will be sent. Such a file is called a signpost. No video information will be stored in the file itself; it only acts as a pass through. At the start of the process the source program will try to send the first frame to the signpost file. However, this frame will only be accepted as soon as there is a target application which will be instructed to start reading frames from the signpost file. As soon as this happens the stream of frames will start and will flow directly from the source to the target application.

2. Usage

Although there is a broad range of applications you can use frameserving for, probably still the most used one is to directly encode a movie from the timeline to MPEG-1 or MPEG-2. Many recent versions of video editing programs do have an MPEG-encoder included, but some of them may not deliver the quality that you would like. Most of them certainly don't have the versatility of a program like TMPGEnc in which you have detailed control over nearly every parameter that determines the quality of the output. So here, we will have a look at frameserving video directly from the timeline from Premiere to encode it with TMPGEnc. If you understand this, you can easily do the same with other combinations of source and target programs.

3. Programs

Avisynth and the Premiere plug in

The most well know program that you can use for video frameserving is probably Avisynth, originally developed by Ben Rudiak-Gould. It consists of a simple dll-file (Dynamic Link Library) that enables programs that can open video files (like players and video processing programs) to open a file containing as list of commands (a script). Such a script usually contains a command to open a video file and next commands to apply filters or perform other operations to that video. It may sound a bit obscure but there are still many video enthusiasts that use it every day.

While you can use Avisynth to send video frames to a receiving application, when you want to frameserve directly from a source application, you will need something that enables you to do the export to the signpost file. Such a piece of software is a plug-in. The most well known is probably the Premiere plug-in, developed by Edwin van Eggelen. Although it was developed as a plug-in for Adobe Premiere it will also work with programs like Flask and DVDx. After Ben Rudiak-Gold seized his activity on Avisynth, Edwin van Eggelen also took over support and further development of Avisynth. His homepage can be found at www.videotools.net. Both Avisynth and the Premiere plug-in used to be freeware, but it appears that a small contribution is now required to get the newest versions. He also has a list of plug-ins for other video editing programs.

Debugmode Frameserver

If you are not interested at the scripting possibilities of Avisynth, an alternative program that you can use is the Debug Frameserver developed by Satish Kumar. It works pretty much the same, but has a couple of advantages. First, it comes with a range of plug-ins for a number of popular video editing programs like Adobe Premiere, Ulead MediaStudio Pro and VideoStudio, Pure Motion EditStudio and Sony Vegas. Secondly, it is supplied as a complete installation file that installs the frameserver and the plug-ins that you want. It does not require any manual copying of files or registering files. Last but not least, it is freeware. It can be downloaded at www.debugmode.com/frameserver/.

4. A simple tutorial

What we are going to do is to frameserve directly from the timeline of Adobe Premiere to TMPGEnc in order to encode it to an MPEG format. We’re going to use the DebugMode Frameserver for this tutorial. The Avisynth method is very similar, so you will have no problem using that if you read this tutorial. Also for other editing programs

First of all it is a good idea to check if the plug-in has been installed in the correct folder. In the Premiere program folder you will find a folder called Plug-ins. All the plug-ins in this folder will automatically loaded when you start Premiere. The DebugMode plug-in, called cm-dfscPremiereOut.prm, should also be in that folder.

Once you are done with your editing work in Premiere and ready to create the video file, select File->Export Timeline->Movie as you would normally do. In the Export Movie window that pops up, press Settings. This will bring you to the Premiere Window where you can select all kinds of export settings. In the selection box select General. When you now open the selection box File Type, you will note that one of the presented choices will be DebugMode FrameServer.

Select that one and press OK. You will return to the Export Movie window where you can select a file name of the file that is going to be the signpost for the frameserving process. When you hit OK the DebugMode Frameserver Window will pop up.

Here you can select an number of settings, like the color space you want to serve in. In this case I have to select RGB32, because YUY2 did not work for me. I have not found any clear directions what color space to use in what situation so you may have to play with it in your specific situation.

I also want audio so I checked also Write audio as PCM samples in signpost AVI.

When you're done, just hit Next and a new window will pop up showing the status of the the frameserver process. Nice feature is that the frameserver window will overrule the main Premiere Window, so you will not be able to accidentally shut down Premiere while the frameserving process is going on.

Now it is time to launch TMPGEnc. One of the great features of TMPGEnc is that it can read video files in many different ways. This makes it one of the most versatile programs. However, this can also lead to situation that TMPGEnc tries to open a file in a certain way and then fails. You can change settings by selecting Option->Environmental Setting and select the VFAPI plug-in tab. This will bring up a list of methods that TMPGEnc uses to access video files. By right-clicking on one you can set the priority of the method. By clicking in the checkbox you can disable the method completely. In order to read frames coming through the frameserver you must disable the DirectShow Multimedia reader in TMPGEnc. Finally, close the Window with OK.

Now you can open the signpost file in TMPGEnc: press the Browse button and select the created signpost file. If there is also audio served, TMPGEnc will automatically detect that and include that in the encoded file. You can now change all the settings that you like in TMPGEnc and encode the source video to MPEG-1 or 2. Make sure that you don't kill the DebugMode Frameserver window as long as TMPGEnc is not ready because this will interrupt the frameserving process.