The Wis Tech GO7007 video capture hardware compression chip was put into a lot of Video Capture devices from 2002 to about 2009.
It was popular during that time because is cost about $10 a chip in bulk and only performed a "Pre-Compression" to a stream format that could prepare it for formal protocol compression into a recognizable standard by a PC attached through a bridge chip like Firewire IEEE-1394 or USB 1.0, 2.0 or 3.0
It was specifically designed as a microprocessor with DSP functions without a specific format target, but also for use in PC devices and not as a single chip solution for a DVD recorder which many other companies targeted with much more expensive chips at the time.
Mostly the "GO stream" output format was a DCT - Discrete Cosine Transform output product which many of the recognized compression products already performed prior to actually performing dissection and redundancy elimination steps. It can be looked upon as a common 'root' step of filtering high frequency 'noise' out of a frame of video before overhauling it in greater detail to compressed frames and groups of picture to further reduce video stream size.
This lightened the 'load' on the PC bus used to bring the stream into the PC for further processing, be that a Mac or traditional PC.
To be sure this could be ISA, PCI or PCI express busses as well as Firewire or USB external connections.
This led to the term or idea of the Personal Video Recorder or (PVR) which gained traction at the time. As opposed to the more familiar Digital Video Recorder or DVD recorder.
Unfortunately with the shift away from 32 bit architecture to 64 bit architecture beginning with Windows Vista and later Windows 7 and 8, 8.1 and 10 many of these devices lost device driver support after Windows based on 32 architecture fell out of favor.
The Plextor ConvertX and ConvertPVR or ADS Technologies and StarTech derived products found themeselves without a device driver and many went up for next to nothing on places like eBay for those who continued to use 32 bit machines.
A couple of vendors like ADS Technologies did produce candidate 64 bit Vista device drivers, which do run in Window 7 x64, however they are hard to find online and ADS Technologies never finished to the point where the candidate device drivers were actually signed with a Microsoft Device Driver signing certificate and can only be used in Test mode.
StarTech which sourced a device called USB2TVTUNER "may be" the last vendor that had an actual robust 64 device driver with signing for Vista, Windows 7, 8 and 10 -- but it is very hard to find, and the 64 bit device drivers were only found after an exhaustive search in archive.org of a remote Mexican website for Doctors. The Startech website download for the 64 bit drivers themselves has long since been taken down and was not archived in whole to archive.org.
The WIS GO7007 was a chip that came with an SDK for Windows and later for Linux. Essentially like many designs of the time the front facing or Input section of the chip depended on a 'video signal preparation' chip, which could be as small as a single wire interface to a composite input, or as complex as a Intermediate Frequency multiplexer coming from a Broadcast Digital Adapter or 'TV Tuner'.
In general however the preparation chip would attempt to select which Input source to switch the inputs of the Wis GO7007 chip, and or route the signal around the chip if plain YUV video capture were the choice.
Then would come the Wis GO7007 chip and its processing to the stream, followed by an interface chip that supported some type of computer bus or firewire or usb. the Wis GO7007 had native support for HPI or USB interface chips and a general purpose interface to I2C or SPI (I'm not sure which). In those days a general purpose serial bus like the I2C or SPI were very popular on cards and external devices, since it required fewer traces to carry short distance serial communications between chips.
Then would come the Interface chip to the PC.
As far as I know the EyeTV 200 device was the only example of a firewire TV Tuner that used the wisgo7007 and it only worked on an Apple Mac with EyeTV software.
Many more examples of wisgo7007 use were available on the PC.
But Pinnacle has a fairly large collection with offerings for both the Mac and the PC, including many TV Tuner devices through the EyeTV software.
On the PC side WIS GO7007 is less known, but well represented. As mentioned the ADS Technologies had the DX2, and possibly the Hauppauge PVR line has some WIS offerings. Startech carried the USB2TVTUNER. And the Plextor line covered both the Mac and PC lines with multiple variants on the ConvertX and ConvertPVR standalone and tv tuner designs.
The general device driver usage of the devices were the same. First go7007 firmware 'blobs' were uploaded to the Wis GO7007 chip and reset to boot as well as other peripheral chips were programmed for their state before assuming the video capture position, and finally commands were sent over the Mac or PC attached bus to commence video capture.
Most Mac or PC attachments operated in in the Master Slave mode, where the video capture device either looped processing frames until data was retrieved, or waited silently for commands to send data.
The actual bus architecture could present possible problems in maintaining capture rate and simultaneous audio and video captures to prevent lip sync problems.
One of the major benefits of using an all in one audio and video capture chip were in that it could decide and take actions to prevent lip sync problems de-arbitraging and simplifying latent decision making processes in code on the Mac or PC, and leading to a fairly stable capture experience.
Hardware encoder chips that dedicated to one capture format or another, and that did not act as general purpose Digital Signal Processors were costly and less adaptable as new standards came out. Throwing the 'baby out with the bathwater' each time a new MPEG format or profile was announced was a common occurrence.
Whether it was a Hardware or Software, or Para-hardware solution however, a great deal of processing power had to be used to convert the analog to digital signals.. and this typically threw off a lot of heat.
Some busses could power the capture device from the bus connection, like USB or Firewire, others could not and required a separate external power supply further entangling the cable set.
The WIS GO7007 had a processing amplifier (or proc-amp) in its driver set which could change the signal processing capabilities of the chip on the fly. Including brightness, contrast, saturation and sharpness. Quixotically.. this last parameter was set to (blur) or very low in the SDK and often left that way. An unobservant device driver writer would over look this 'bad' setting and result in a default video capture bordering on 'Terrible'.. but at the incredible price of $10 a chip.. it was assume par for the course.
Changing this value manually within the capture driver after startup (which always resets to the 'terrible' setting on reboot) provides some [Spectacular] video capture results.
