Digital Video Broadcast analysis

Digital TV has many drawbacks and is very slow to respond. A great deal of utility is possible when used in a PC as opposed to a stand alone unit. A friend threw away their DTV box from GE because it was just too irritating to use. So that piece of junk is where I start to get some utility from the device and see what comes of it. First there is the over view. There is an infrared receiver chip that outputs a 5v signal on an infrared signal and so that gets robbed to be an Infrared remote control tester and analyzer. The radio frequency part uses two standardized chips that are I2C serial control oriented. An additional chips serves to convert the channel information into an MPEG-2 stream AFAIK. From there it is converted to video and then modulated to channel 3/4 and sent to a standard TV.

Linux has an application called dvbsnoop, which I found by way of Google. So I did "aptitude search dvbsnoop" and got "p   dvbsnoop - DVB / MPEG stream analyzer" and so apt-get install and man.

This is going to be more difficult than I thought. The standards will require some time to analyze and put into a form that makes sense.

The biggest problem with the GE unit is that it has bad code. It will overwrite itself when running and I assume it has memory leaks and various other code problems. It will actually reset itself on some broadcast signals and clear all flash memory. It is a POS and that means Poor Operating System or something else.

I suppose I will do some research on MPEG-2 and figure out what information is in the format and why it is so cumbersome to use. I suspect it is the attempt to reduce bandwidth by compression and they just went nuts because they could do whatever they wanted.

There are many resources available including slides from John Hopkins course in MPEG from 1 to 4.

I suspect it will be about 8 hours of study on and off before I get the hang of the process. Lots of concepts interspersed without much order to it, but perhaps that is because it is unfamiliar. So diving into spec as a subtask. I also need to set up an I2C analyzer interface to list the I2C traffic and identify its effect as well as generate commands. I suppose one of the single board computers with a serial interface will do that as well as some ADC on signal states. The whole thing is riddled with patents on concepts and what a load of crap. "A method to make rat feces look like gold" has been patented and expired long ago. Why exactly would a person create a free medium which was technologically encumbered? It is surely just some tool to consolidate power and not deliver information. On any given day, the content repeats and is still broadcast continuously in loops. Why exactly is it necessary to transmit a commercial that is the same 50,000 times in the period of a week? The design is created to jerk people around IMHO. If it is old data that I have already captured and stored a simple large UUID could identify a complete block of information and compression would be millions to 1. The availability of massive amounts of storage allows a different approach. I want a laugh track on my computer so I can insert laughs in the news and commercials.

I have tested the RF interface and found the control of it lacking in creativity. It has utility that is not available unless I program it myself and the entire system will be stripped out and interfaced in new ways. The RF tuner is actually very easy to control and I2C makes it easy to interface. It is all 5V and generates the video out at .5v P2P cleanly. At least that part is consistent, the rest is a horrid kludge of poor design.

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