Smooth FF/RW

DivX Plus MKV extension: Smooth FF/RW

Have you ever been frustrated when trying to fast-forward or rewind a video because your player becomes unresponsive and the video skips large chunks of time unpredictably making it hard to quickly find the scene you're looking for? Rewinding can be particularly infuriating using CDs or DVDs, and with downloaded video even faster media can still be problematic due to the long and irregular gaps between keyframes.

DivX Plus offers an extension to the MKV container called Smooth FF/RW that helps to solve this experience problem by including a special navigation track in your MKV file during authoring. This extension is supported by all DivX Plus devices and gives you the option to trade a small filesize overhead for a much better navigation experience. This article shows how you can try this new feature with the easy-to-use DivX Plus Converter as well as providing information and sample tools that you can use to author this feature manually or to add support in your own encoding tool chain.

Encoding with x264

Encoding DivX Plus HD video bitstreams using x264

x264 is a popular H.264 encoder whose source is freely available under GNU General Public License (GPL).1 It can be used to encode video bitstreams for DivX Plus HD MKV files which are later combined (muxed) with other assets such as audio tracks and metadata.

The DivX Plus HD format is designed to bridge the gap between desktop computers and consumer electronics (CE) devices such as DVD players, set-top boxes, connected devices, and portable media players. Wheras desktop systems can play media with a wide variety of characteristics so long as they are powerful enough, playback support and experience on CE devices is constrained by numerous factors: the capabilities of the decoder hardware, network bandwidth, drive read rate, memory I/O performance, renderer capabilities and display properties.

The DivX Plus HD profile establishes capabilities that will be met by all DivX Plus HD certified devices. By configuring an encoder accordingly, you can be assured that your content will play well wherever the DivX Plus logo appears.


Builds Tested

The information in this article was derived using x264 builds up to version 1301, but should also apply to later versions. Read our recommendations below to find important information for particular ranges of builds.  If you have feedback or suggestions please let us know via the DivX Plus HD forum.


Bitstream Properties

Here we describe key arguments that you should pass on the x264 command line to produce a fully DivX Plus HD compliant video bitstream.

Embed Code Generator

DivX Web Developer Guide

The DivX Plus Web Player plug-in gives any webmaster a simple and hassle-free mechanism for offering DivX (DivX/AVI) and DivX Plus HD (MKV/H.264) videos for immediate download and playback on their website by simply hosting the video file and editing some HTML tags.