M-JPEG analyzer
Is there such a thing as an M-JPEG analyzer? We are using 22 CellStack codecs for audio and video, both for conferencing and streaming to Time Warner Cable. This is over an ATM (Cisco) network.
Cary Lahnum,
Orange County Broadcast Systems Engineer
Eric Hodges, Americas Marketing Manager, Tektronix Test & Measurement, provided an answer to the question.
The answer to this question depends somewhat upon what type of analysis is desired. I'll address the two primary possibilities with the answer:
If you want to assess the impact Motion JPEG compression has upon your content quality, then yes, there are tools available to perform this type of analysis. For example, a reference-based tool such as the Tektronix PQA300 would be capable of comparing the original content (either serial digital or composite analog) with the resultant content (post-compression/decompression) and providing measurements that indicate both perceptible changes in quality (based upon the human vision model) and changes in content on a bit-by-bit basis. Even single-ended picture-quality tools would be capable of providing information on the impact to your content quality, as long as they include the capability to monitor for Discrete Cosine Transform-based errors, since M-JPEG does use DCT as part of its compression process. The PQM300 would be an example of such a tool.
If your intent is to analyze the actual protocol of M-JPEG, your task is more difficult, since I am unaware of any tools available to do this type of analysis. At Tektronix, our focus is on MPEG and its complementary standards (DVB, ATSC, ISDB), since they are the primary compression standards of the professional broadcast world.
More comments on the August editorial, Could dead birds derail DTV?
Never saw one….
In all my 34 years in broadcast television, I have never, and I mean never, seen a dead bird under or even near a broadcast tower — let alone seen one hit a tower or guy wire. I won't say this never happens, just that I have never seen it happen. I did hit a bird the other day with my car — don't tell anyone because I live 17 miles from the station and don't want to walk.
Al Gillett
Asst D.E.
WSYT Television 68
Dear Editor:
Regarding the editorial “Could dead birds derail DTV?” I was dismayed to read that ornithological groups are petitioning the FCC to deny 40 tower applications until the FCC conducts environmental studies. How long will that be? I feel that this request is unreasonable, as are requests to remove tower lighting, to severely limit tower height and locate towers in the middle of nowhere. Towers are being singled out unfairly for their role in bird deaths. Many birds perish from colliding with high-rise buildings, power lines and automobiles, but these objects are not being contested.
Based on what is currently known, lighted towers and corresponding guy wires appear to pose a threat to birds on overcast nights. Unlit towers over a certain height pose a threat to aircraft on clear and on overcast nights. Bird lovers suggest removing tower lighting. The FAA will never approve this plan. Although I found the content at www.towerkill.com worrying, my concern for birds was tempered by a picture at www.towersafe.com depicting a passenger aircraft about to collide with an unlit tower. In my Internet search, I also found a cleverly named bird organization called FLAP (Fatal Light Awareness Program) at www.flap.org. “Tower kill” of birds is unfortunate, but protection of human life through tower lighting needs to take precedence.
I think that the tower industry should pursue the goal of making towers as harmless to birds as possible, without compromising tower function or human safety. When thorough research finds the exact causes of bird-tower collisions, and reasonable solutions are created, steps should be taken to make towers safer for birds. Until that time, new towers should not be denied or delayed, and existing towers should not be modified because of birds.
Vicki Kipp
And finally…
The EPA staff is well-trained
…and then there was the sweet young lady just out of college a year or two who was performing phase one EPA studies on selected tower sites for a new owner of our properties. She told me with a very straight face that the purpose of those red lights was to “keep birds from running into towers.”
Name withheld to protect the innocent from EPA reprisals
