Help for kwintv

Version 0.4.0

kwintv is a X11 application based on the bttv-driver by Ralph Metzler.

kwintv allows you to watch TV in a window on your PC screen. It has more or less the same abilities as xtvscreen
which is included in the bttv-driver package, but it is based on Qt, a C++ GUI application framework by Troll Tech.

The bttv-driver supports several frame grabber cards based on a Brooktree Bt848 or equivalent cips like the Win/TV series by Hauppauge and others. For details see the bttv-driver homepage.

 How to set up a channel
 How to make screen shots
 How to capture a video clip
 How to get the volume mixer working


How to set up a channel

To add a new channel, click <TeleVision><Channel><Add> or open the channel box and klick the button with the
+ sign in the toolbar.
In the channel setup dialog, click the channel number to get a complete list of all aviable channels.

To get the correct correspondence between the channel number and the frequency representing the channel, you have to choose your country once in the channel setup dialog.

If your country is not supported by kwintv and you want to add new frequency - channel relations, have a look
at the files kwintv/countries.cpp and kwintv/countries.h.
Please mail me any changes you did in these files!


How to make screen shots

Simply click the screen shot button in the toolbar or click <TeleVision><Screen Shot>. The screen shots are saved in the directory kwintv was started in and are named pic????.pnm whereas the questionmarks are replaced by some digits. Existing files won't be overwritten.
Actually, the screen shots have the same size as the tv screen.


How to capture a video clip

Click <TeleVision><Video Clip> to open the video clip capture dialog.
Chooose the image format and dimension and click the <Start Capture> button. Click the button again to stop capturing.

kwintv creates a file type called AVI (Audio/Video Interleaved) on your hard disk. This file contains digitized video and, optionally, audio. Audio capturing will be added in a later version of kwintv. The video clip will be written to a file called "./temp.avi", which you can save to another file after finishing capturing. In a later version it will be possible to change the name and path of this temporary file. If you really need to change this file, edit the kwintv recourcefile located in ~/.kde/share/config. The keyword is "vc_tempName".

There are several image sizes one can choose. The maximum suggested video image capture size is 320x240. When capturing on slower PC's, a smaller image size might be needed.

kwintv can use several different types of color formats when capturing video clips. For highest performance, choose the BTYUV format. This gives excellent capture image quality and frame rate, bit will give slow performance on playback of 320x240 image size videos. This format is great if you plan to edit or compress the videos later.

If you do not plan to edit the video and want good playback performance, choose a smaller image size or try RGB15 respectively RGB16 instead of BTYUV.

Capture and playback performance is determined by your system configuration, including CPU and hard disk speed. On a P133 with a medium fast HD, a frame rate of 10fps with an image size of 320x240 and RGB15 format is possible.

One word about lost frames. Every few seconds there might be a number of lost frames, up to ten. This is because linux pauses while writing a few MB to disk. Starting the update daemon with 'update -s 1 -f 1' (writes data once a second) should help a bit if you have problems with missing frames.

Remark: In this version of kwintv, the BTYUV format does not work, sorry!
 
The frame rate is fixed to 10fps. This will change in later versions. If you need to change the frame rate, edit the resource fiel located in ~/.kde/share/config. The keyword is "vc_fps".


How to get the volume mixer working

At the first start of kwintv you will get an error message like this:

mixer: cannot find mixer channel Vol
mixer: aviable channels are:
mixer: Pcm    4
mixer: Spkr   5
mixer: Mic    7
mixer: Mix    9
mixer: IGain  12
mixer: Line1  14
mixer: Line2  15
mixer: Line3  16

To get the volume mixer working, you have to choose a feasonable mixer device in the <Options><General Options> dialog.

Remember: the audio cable of your grabber card has to be connected to the line in of your soundcard!