InstallationInstallation went very smoothly, no hiccups and after rebooting my portable I was able to watch digital television. Well okay, I must confess everything didn't go as smoothly as it should. Where I live there is no reception of DVB-T signals, at least not when using the Compro DVB-T antenna. Lucky me my father never throws away old trash and so I found myself few days later installing the old analog antenna back on the roof, back at ground zero I popped open the ComproDTV 4 software and after autoscan completed I was now entering the realms of digital terrestrial broadcasting.
Compro FM exploredComproFM is Compro's tool for offering FM audio via the VideoMate U2800F. Upon opening ComproFM starts an autoscan of all the available FM radio channels.
A very simple and complete user interface allows you to browse through the FM radio channels. You can easily record and listen back to your recordings, pause, stop, fast forward and fast rewind. You can also enter the option menu or set up your recording schedule.
Compro DTV exploredJust like with ComproFM you get the automatic channel scan upon launching ComproDTV. If you don't any get any channel you can easily adjust scanning settings in the option menu, you can also check other video sources as well, S-Video for example. After that you should get something like this:
The ComproDTV user interface hasn't been made over-complicated: it gives you all the nice features quickly accessible without having to really search for them. The icons aren't all self-explaining but it takes only few minutes of playing around to discover what's behind each of these buttons. The top panel shows the time of the day, the video source, the channel number, the DVB-T signal reception and the audio level. The bottom panel allows you to switch channels via the up/down buttons, increase/decrease the sound volume, record and watch recordings, select audio output mode (left/right/stereo), enable channel surfing, enable window mode and add windows, enable subtitles, enter Teletext mode, enter EPG menu, take snapsots, make a timeshift (via a buffer), switch video source, schedule, repeat playback, go to last channel and enter the options. All together this tool provides the many basic video recorder options you're used to and many more. Let's highlight some of these cool extra capabilities:
channel surfing mode activatedClicking the Channel Surfing button will make the ComproDTV loop through all available channels, every 2~3 seconds it jumps to the next channel and takes a screenshot, in the end you get a good overview of what shows are currently going on at each channel. After the loop has been completed it starts all over again. It's a bit like the mosaic channel with the difference that here everything is done at the user side, not at the side of the TV provider. If there is no mosaic available this feature might come in handy.
sub-window feature at work The Sub-Windows feature allows the user to create a second and an even a third or fourth sub-viewing windows. The strength of this feature is that you can view 4 different TV channels real-time, you can scroll through all available channels and enable/disable mute per window. Adding windows can easily been done via the main user interface. Biggest surprise to me is that all channels played fluently, it is not like each channel was suddenly being showed at 5fps.
Picture In Picture modeA great addition to the window mode is that you can move the sub-windows into the main window via the Picture In Picture feature. You can now follow who's winning the soccer match whilst your wife is watching The Bold And The Beautiful!
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This said, I was looking for Linux support but unfortunately there non such, Compro simply hasn't got any drivers for it. I ended up opening the device to have a look at the internals and it seems Compro is using a Trident TV Master TM6010 video decoder. On linux.org I found the following info:
Michel Ludwig (michel.ludwig gmail.com) did some development mostly focused at DVB-T of tm6000. Mauro Carvalho Chehab did some development moslty focused at analog support, and extended support for tm6010.
There are some versions of the driver at http://linuxtv.org/~hg that merged both developments.
The driver is still at the TODO list, however its development is currently frosen. Mauro intends to return back to it, but this is not on his current top priorities.
Those chips are very buggy and they behave badly if the driver doesn't do exactly the same thing as the original one (it starts to loose frames). The reason is unknown, but it is suspected that there is a firmware or hardware bug at those chips.
Maybe the conversion of the driver to the new i2c approach could help to fix this issue, since this will avoid sending probing packets at i2c bus, as it is known that some i2c probe sequences can hang those chips.
Also, on all tests we've done so far, it can't reliably read data from an i2c device. This prevents that tools like scan work, since you can't be sure if a signal lock happened. Also, driver can't even be sure if xc3028 firmware were successfully loaded on this device.
It is important to notice that the vendor (Trident) doesn't seem to want helping with open source development. Contacts with the vendor were tried during 2007 and 2008 in order to get their help by opening docs, via Linux Foundation NDA program, without success.
The vendor also seems to be refusing so far to help the development of a driver for their demod DRX-K line that they acquired from Micronas (as pointed at http://linux.terratec.de/tv_en.html).
In brief, while we want to fix the driver issues, it is recommend to avoid buying any devices with tm5600/tm6000/tm6010 (and DRX demod) chips.
It seems that these random crashes could be caused by a firmware runtime error, although I can not confirm this and neither did Compro at the time I asked them about it. I'd say better be warned...