News | TV Schedules | Digital TV | Radio | Community Scroll | About Us | Contact

The story behind our conversion to HEVC

Just over two years ago, the Aniik F2 satellite started to seriously fail.  Already well beyond it's "best before"
date, Anik F2 started to transmit lower & lower quality signals, a problem that could not be fixed. (Today, Anik
F2 is just so much dead space junk, some 25,000 miles up.)

So, the decision was made to transfer all the signals to the much newer ANIK G1 satellite.  Unfortunately, the transponder space on G1was already full.  So, the decision was made to employ HEVC (High Efficiency Video Coding), which allows the same quality, while consumng only half the bandwidth.  This, in turn, meant the previously full Anik G1 now needed only half the transponders, thus freeing up the other half to carry the
signals that were on the old Anik F2 satellite.  For us, this change occurred in the last week of February.

But, HEVC had never before been used commercially, and there were (and still are) problems with it's transmission, with many companies and societies like ours, still experiencing a multitude of problems.

We changed antennas, L-Band pre-amps and several signal splitters, all in an effort to get a better signal.
These things helped, but did not solve the problem. In turn, the supplier of our Transcoders (the bits that
convert HEVC to Mpeg 2, which the rest of our equipment understands)  kept trying to improve their
software.  Every itterantion improved things, but still did not solve the problem.

Then, some weeks ago, Sencore thought they had the cure. We installed that update, which seemed to work,
but quickly discovered it had a flaw in the code, which turned about 5% of the TVs in town into bricks that
no longer worked!  So we quickly reverted to the previous version.

Early, last Thusday morning we uploaded a still newer version of the firmware.  All the TV's in town continued
to work and the "wandering sound" (lip-sync) issue that has plagued us since February,
now seems to be solved.

It was done through some very clever engineering. Instead of timing every signal off an internal clock (as
the standard calls for), Sencore's engineers synchronized the sound using the PCM (Pulse Code Modulation) signals which are used to transmit the sound portion of a TV signal. Thus, if the sound wanders, the system
now automagically compensates!  And, it works!

That said, if you have an older TV and you change the channel to find the lip-sync out by a bit, just wait a
minute or two and it will come back into sync.

Lastly, we had a problem with intemittent drop-outs, that caused the picture to be lost, followed by a white
screen and then a negative image, and then a proper one. This turned out to be a problem unrelated
to the lip-sync issues above.  We go that fixed a few days ago, and the system seems to be running
well, for the first time since February!

We thank you for your patience, while everyone involved worked through this.
Last updated: Nov 30, 2024