User manual TERRATEC DIVX RECORDING

[. . . ] Aureon/DMX6fire/EWS) The DivX codec (available for free under http://www. divx. com) The Fraunhofer MP3 codec (should have been bundled with your Windows, otherwise it can easily be downloaded) or an alternative MP3 codec (like Lame). - Of course your TV card must be properly installed, and the same applies for the soundcard as well as the rest of the system. To ensure that your system is properly configured for managing large data streams, it is advisable to read the Audio Tweaks tutorial available on the TerraTec Website. Recording Tutorial Let's get started: After these few easy steps you will have a pretty nice DivX AVI file on your computer: Step 1: Installing DivX and the codecs This is done by downloading the latest DivX codec pack and executing it. If you want to check which codecs are installed on your computer, click "Audiocodecs / "Videocodecs" in the "Audio, Video, Game Controllers" section of the Device Manager. Feels just like watching TV: Launch TerraTV and choose the source you wish to record from. [. . . ] A usual value is 780 kb/s, a value between 780 and 900 kb/s should be a good default setting. In a normal movie there are scenes without a lot of motion which can easily be compressed more without visual artefacts surfacing, but there are also scenes with a lot of action which contain so much detail that you need more data to store it without impact. In general, variable bitrate encoding requires more CPU power but offers better compression results. General Parameters This looks similar to the general setup of an MPEG codec, and seeing as DivX is basically a modified MPEG-4 codec, it makes sense. To explain this setting, we have to dig a bit deeper into MPEG compression technology. MPEG knows 3 basic image (frame) types (and some more advanced settings like motion vectors, but we will not examine them here). The first one is the I-Frame (Intra), which is simply a complete image. The second one is the P-Frame (Modifies Predicted Image), which contains only the information that can change the last I-Frame to a frame that would represent the next frame. This means { I-Frame 1 , I-Frame2 } (almost) equals { I-Frame 1, (I-Frame1 + P-Frame 1) }. Another one is the B-Frame (Bi-directional), which corresponds to the P-Frame, with the difference that it can also be related to the next frame. According to the encoded material the encoder uses a specific frame type sequence, the so called GOP (Group of Pictures). This GOP always begins with an I-Frame and has a specific duration (per default 300 frames). So the keyframe interval is the interval between two I-Frames, which represents the GOP-length. The higher the value, the higher the compression factor, with a negative effect on the quality. In other words: The lower the value, the more complex the scenes can become without causing visual artefacts on the compressed file. For example, cartoon movies can usually be compressed with a higher keyframe interval, action movies should have an interval equal to the default setting or lower. It would be possible, for example, to encode the daily news (without the video reports, just the newscaster) with just one I-Frame (Keyframe) and lots of P-Frames. The scene change threshold affects the automatic keyframing setting, which breaks and restarts the GOP when the scene changes are too complex for managing them with Pand B-Frames. [. . . ] The file that results from the recording is your new DivX compressed file. :) Useful Links To explore even more possibilities of recording with DivX, here are some links and programs that can help: 1. Virtual Dub Virtual Dub is one of the best video cutting and converting utilities. With a size of less than 1MB it fits on a floppy disc and can do everything from transcoding videos up to cutting out commercials from your favorite TV series. [. . . ]