Absense of Video Detection

Thread Starter

yourownfree

Joined Jul 16, 2008
98
What i want to accomplish is to detect video to see if a commercual ad was played or not. No specific ad just need to know if there was an absense of video when the video ad should have played. This is for a tv broadcast station use. As it is now the only way to know is to go back and review the recording. A light should come on for the master control operator to see. I am looking for ideas and info on this. I am limited on my knowledge but one idea i have is to use a digital tv converter box for analog tv. Use the composite video to see if there is any video. Design a detection circuit, then use an arduino circuit as data logger to flash an led, to record the time of incident and to visually show the time of the incident. The led and circuit can be reset at any time manually. As a note here the tv station is broadcasting in digital not analog. I am here in the U.S. so using 8vsb scheme. Also there are up to 7 channels of video to detect from just one station frequency. This station operates more than one channel frequency, like channel 12 and channel 38 as an example, but keep in mind there can be 7 subchannels for each. If there was a way to step through these with one device it would be better. but a light is needed for each subchannel.like tv station channel 12.1,12.2, 12.3 etc so the master control operator knows which channel did not play the ad. For clarification, if the ad doesnt play they cant charge the customer for that ad spot. So any help or ideas are greatly appreciated. Thanks
 

dl324

Joined Mar 30, 2015
10,758
What i want to accomplish is to detect video to see if a commercual ad was played or not. No specific ad just need to know if there was an absense of video when the video ad should have played. This is for a tv broadcast station use. As it is now the only way to know is to go back and review the recording. A light should come on for the master control operator to see. I am looking for ideas and info on this. I am limited on my knowledge but one idea i have is to use a digital tv converter box for analog tv. Use the composite video to see if there is any video. Design a detection circuit, then use an arduino circuit as data logger to flash an led, to record the time of incident and to visually show the time of the incident. The led and circuit can be reset at any time manually. As a note here the tv station is broadcasting in digital not analog. I am here in the U.S. so using 8vsb scheme. Also there are up to 7 channels of video to detect from just one station frequency. This station operates more than one channel frequency, like channel 12 and channel 38 as an example, but keep in mind there can be 7 subchannels for each. If there was a way to step through these with one device it would be better. but a light is needed for each subchannel.like tv station channel 12.1,12.2, 12.3 etc so the master control operator knows which channel did not play the ad. For clarification, if the ad doesnt play they cant charge the customer for that ad spot. So any help or ideas are greatly appreciated. Thanks
WOW! What a wall of text. TLDR.

I had a VCR that could skip commercials. It worked by detecting the dark period before and after them. It wasn't foolproof, but worked well enough.
 

ronsimpson

Joined Oct 7, 2019
684
It is very hard to detect lost video.
What about if the wrong add runs?
What does the video look like if the add does not run? Blue or black or test pattern? white noise?

Years ago in radio I worked on some of the first automated stations. The tape recorders have 3 channels. Left, Right and (I don't remember the name for the 3rd channel) The transmitter got L and R. On the third channel we recorded in ASCII the name and description of the commercial. The third channel went to a printer. Each line had the date, time, and this description of the commercial. At the end of each day we saved the paper copy of what played.

The reason I remembered the radio stations is that my TV picks up data from the transmitter. There is the CC data, there is data to say what program is on now and the next 4 hours of programs. There is much data hidden in the video. I know how the CC works. There must be more data in the video. I don't know if the commercial have this type of data hidden in them. If so then I can see a easy way to record that.
----edited----
You might get the information you want by simply looking at the audio level. Commercials and programs so not have 10 seconds of no audio. It is not a good way but might work.
 
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Thread Starter

yourownfree

Joined Jul 16, 2008
98
I did think of audio. It would be easy to do it that way i guess. I could use a timing situation for the window of time it allows for silence and if it stays silent for x length of time then start anoying people. but then there will be some odd commercial with no sound. Ronsimpson, not sure about if a wrong ad plays. From what I understand its just if an ad doesnt play at all. I wonder if the commercials do have hidden data? Anybody know if thats true or not? dl324, you mentioned your vcr had that function to eliminate the ads. It made me just recall I thing Popular Electronics had a project to eliminate ads. It would know when the ad started. It may have been when the level changed and went black, not sure. I will dig that up and see.
 

dl324

Joined Mar 30, 2015
10,758
It may have been when the level changed and went black, not sure. I will dig that up and see.
The VCR detected the blank (dark) period before and after the commercials. Dark scenes in the show being recorded could fool it and it would fast forward through them. It didn't happen frequently, but it did happen.
 
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