4 5
2.3 Bitrates
The bitrate of a videole (stream) denes how much data is transferred within a specic time. For video, the
bitrate is usually measured in Mbit/s (Megabit per second). Some Programs also use kbit/s. 1000kbit/s equal
1Mbit/s.
Average bitrates for DVD are between 4Mbit/s and 9Mbit/s. The more complex motion paths and content of
the video image become, the higher the bitrate needs to be for an accurate reproduction.
The recommended average bitrate for material encoded to be used with KCE-635UB is between 1 and
3Mbit/s. Higher bitrates don’t necessarily improve the image quality, but inate le sizes and may cause prob-
lems in playback.
2.4 Compatibility Guideline
The chart below (taken from the KCE-635UBs Owner‘s Manual) gives an indication about les which can be
played back by the KCE-6335UB.
However, there are more factors than the ones stated in this list. Sometimes encoders add invalid data to the
header of a video le that prevent playback on KCE-635UB although all parameters seem to be within speci-
cation.
KCE-635UB
1. Initial Considerations
1.1 What this guide can do
The intention of this guide is to help you to get the most out of the KCE-635UB. We aim to give you guidelines
to the creation of own content from your recorded DVDs, Videos etc. Content from websites with user genera-
ted content, such as YouTube become also more popular these days. We will give you an idea how to get such
content into your car with the KCE-635UB. Finally, we will show you how to analyze a video le in order to be
able to determine if KCE-635UB can play it back without prior conversion. The tools we use are either freewa-
re or the most popular applications used in Western Europe. We avoid exotic command line driven hardcore
tools. Our aim is to offer at least one commercial and one freeware solution for each of the tasks.
1.2 What this guide can’t do
There is an overwhelming number of different video formats out there that may or may not be compatible with
the USB Video player. We are not able to tell you which of these formats will work or not. Especially with con-
tainer formats, such as AVI, anything may be inside.
We won’t assist in any illegal activities such as converting content from copyright protected DVDs.
Mac and Linux users are welcome to create a similar guide, we can’t give any advice for anything but the appli-
cations mentioned in this guide under Windows Operating System.
This guide is not a scientic paper on video encoding techniques; some areas are not discussed in depth.
We don’t aim to replace the instructions which come with the software described.
2.1 Which Format is the best?
The answer to this question depends on what you are going to do with your video les. If you are going to use
them with the KCE-635UB only, you might want to stick to DIVX, if you use another portable device, MPEG4 or
Windows Media might be better for you. However, it is likely that you are required to process separate les for
your KCE-635UB and another portable device.
2.2 Which resolution is best?
The resolution you choose for your video les shall not be higher than the resolution of the screen.
Alpine screens have a resolution between 400x234 up to 800x480. This may sound low compared to a PC mo-
nitor which won’t do anything less than 1024x768. But nobody will disagree that a DVD delivers a pretty good
image quality. A DVD’s maximum resolution is 720x480 (NTSC) or 720x576 (PAL).
On the other hand, the size of a screen is another factor. Typical in-dash screens are around 7 inches, any
resolution from 320x480 will deliver good results. If the resolution of the video material differs from the ‘native’
resolution of the screen, the image will be electronically scaled to t. This does not necessarily improve the
image quality. As a rule of thumb, try to match the screen’s number of lines (234 or 480).
KCE-635UB
2. Formats, Resolution, Bitrates
