Movie Conversion Tools FAQ

Posted Tue, 03/10/2009 - 22:37 by drapeau
Transcode

Movie Conversion Tools FAQ

Subject: Introduction

This is the Frequently Asked Questions list for the Movie Conversion Tools product. If you have a question and cannot find your answer here, please send mail to support@transcode.com.

Subject: Questions

Subject: How do I create a QuickTime movie?

Use the "-format QuickTime" option. For example, if your original Parallax movie is called "jpegMovie", you can create a QuickTime movie called "qtMovie" by invoking ConvertMovie like this: 
ConvertMovie -input jpegMovie -output qtMovie -format QuickTime
(You may substitute "quicktime" or "qt" for "QuickTime" above.)

Subject: How do I create an AVI movie?

Use the "-format AVI" option. For example, if your original Parallax movie is called "jpegMovie", you can create an AVI movie called "aviMovie" by invoking ConvertMovie like this: 
ConvertMovie -input jpegMovie -output aviMovie -format AVI
(You may substitute "avi" for "AVI" above.)

Subject: How do I found out all of the program's options?

Type 
ConvertMovie -help

Subject: What does the "-411" option do?

It converts 4:2:2 YCbCr-encoded JPEG images into 4:1:1 YCbCr-encoded JPEG images. Essentially, it converts from a higher-quality version of JPEG into a slightly lower-quality version that is more widely acceptable by software and hardware JPEG playback engines. This option is provided to help you make your Parallax movies playable on the widest possible variety of platforms.

Parallax hardware uses C-Cube Microsystems's CL550 chip for hardware-assisted JPEG compression. As the first step in compression, the C-Cube chip converts RGB pixels into a different color space called YCbCr (a digital version of the "YUV" colorspace, in case you're familiar with YUV). The "4:2:2" means that some pixels in the original image have some of their color information thrown out before compression: for every four pixels of "Y" information there will be two pixels of "U" and "V" information. "4:1:1" means that for every four pixels of "Y" information there will be one pixel of "U" and "V" information, which means that 4:1:1-encoded images have less color information in them than 4:2:2-encoded images, which can result in lower image quality. However, some JPEG hardware and software engines can only deal with 4:1:1-encoded JPEG images. So, in order to play back movies that were originally created with Parallax hardware, each JPEG image in the original Parallax movie needs to be converted from 4:2:2-encoded JPEG data into 4:1:1-encoded JPEG data. This conversion does throw away some information, but the resulting movie is playable on JPEG engines that can only deal with 4:1:1 JPEG data.

Subject: How can I create streaming video movies for Web distribution?

Using ConvertMovie is the first step, producing a QuickTime or AVI movie. The next step is to use one of several streaming video encoding tools, such as VXtreme's Web Theater product, which can convert AVI movies into VXtreme Web Theater movies. ConvertMovie can successfully produce AVI movies that Web Theater can use to create VXtreme streaming videos. However, since JPEG is not one of the standard Video for Windows codecs, you will need to install a JPEG codec driver if you are running Windows NT or Windows 95. You can find a free JPEG codec at Paradigm Matrix. Progressive Networks also has tools for creating streaming videos from QuickTime or AVI movies, but they do not yet support JPEG codecs.

Subject: I have a JFIF still image but I can't use Parallax video hardware to display it. Can you help?

Yes. Use the ConvertImage program to convert a JPEG image into a Parallax-compatible JPEG image: 
ConvertImage -input originalImage -output newImage -422
ConvertImage converts JFIF ("JPEG File Interchange Format") images into the 4:2:2 YCbCr-encoded JPEG images that Parallax products work with.

By the way, if you have Parallax JFIF still images that you wish to convert into 4:1:1-encoded JPEG images, simply omit the "-422" option.

Subject: What if I can't find my answer here?

Send in your own questions! What do you think belongs in this FAQ? Let us know by sending a message to support@transcode.com. In most cases, you should receive an answer within 24 hours.

webmaster@transcode.com