# Why No Ad-blocking for Cable TV? **URL:** \ **Category:** Factual Questions\ **Created:** [July 12, 2016, 6:09pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733 "2016-07-12T18:09:56Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 12, 2016, 10:53pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/21 "2016-07-12T22:53:18Z")
> [@Slash1972](#): > > You could just not use HDMI cable to connect the cable box. Or get a license for the technology and decrypt, scan for commercials, re-encrypt and send to the TV. The device would be used for ad-block, not copying or anything like that. You can use composite cables rather than HDMI but my understanding is that you’re not going to get a full HD signal unless you use HDMI cables. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 12, 2016, 11:02pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/22 "2016-07-12T23:02:55Z")
> [@Dewey\_Finn](#): > > Based on what **Amateur Barbarian** says above, no, there is no signal that can be read as the start or stop of an ad. > > But even if such a thing did exist, where would the ad-blocker be running? It sounds like it would need to be running either in the cable box or on the TV itself. There is, though. Well, kinda, I’m not sure how it’s implemented. With Tivo some shows (maybe about 20-30% of them) are tagged with the word SKIP. On those shows when a commercial starts you can press a button on the remote and the jumps right to where the commercials end. (If you were to hit the button again, it would go to where the next set of commercials end, it’s the _end_ of each commercial segment that the skip function looks for). However, I have no idea who puts that bit of code in the show. Could be someone at TiVo hand programming, could be the broadcaster/network, could be the studio, I have no idea. No matter who does it, I’m guessing everyone involved has to give their okay, probably including the advertisers. And, of course, the skip feature doesn’t work until after a show has recorded, if it hasn’t recorded, there wouldn’t be anything to skip. It’s like when I first got a TiVo 15ish years ago, as soon as I’d show it off the first thing everyone would ask me to do is fast forward. Well, um, I can’t do that until we’ve been watching for a few minutes (and I rewind first). Also, someone mentioned 30 second skip. That’s how I have my TiVo remote programmed. I can skip through commercials really fast that way. Just hit the button a few times, and hit instant replay (backs up 7 seconds) once or twice if I over shoot and I need to see what I missed. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 12, 2016, 11:04pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/23 "2016-07-12T23:04:50Z")
I was talking to someone who has the thirty-second skip button programmed but also added a three-minute skip button. The theory is that most commercial breaks are about three minutes. I’ve been meaning to add that. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [July 12, 2016, 11:36pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/24 "2016-07-12T23:36:55Z")
> [@Dewey\_Finn](#): > > I’m not sure what you mean. I have ad blockers on my Internet browsers, but then I control the computer including what programs run on it. I have no control over the software on the cable box, so the only way I can see for ad blocking to work there would be with the cooperation and support of the cable provider. But that’s going to piss off the content providers. This is the crux of it. With the notable exception of things like Tivo’s “skip” feature, cable providers have a vested interest in _not_ making it easier for you to skip ads. ---
**Author:** ![Duke\_of\_Rat](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Duke\_of\_Rat](https://boards.straightdope.com/u/Duke_of_Rat)\ **Post date:** [July 12, 2016, 11:42pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/25 "2016-07-12T23:42:45Z")
> [@Dewey\_Finn](#): > > If you’re using an HDMI cable to connect the cable box to the TV, a technology called [High-bandwidth Digital Content Protection](https://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection) may prevent you from mucking with the program like that. As I understand it, the idea is to encrypt the signal so people can’t record HD channels. HDCP can be stripped from an HDMI source with a simple HDMI splitter. I’ve heard it’s handy to get around handshake issues, too. I record practically everything to the DVR and manually zap through the commercials 30 sec. at a time. The DVR remote even has a button that skips 30 sec. at a time. One of my classic gripes was when DirecTV denied me the major network feeds because they said I should be able to receive them OTA. I couldn’t. They could have given me a waiver to get the east or west network feeds, but said that would deny the local affiliates their commercial revenue. And then told me they could upgrade my receiver to a DVR - one of the boiler plate list of features was so the customer could skip commercials. Go figure. ---
**Author:** ![Backwater\_Under\_Duck](https://avatars.discourse-cdn.com/v4/letter/b/ba8739/32.png) [@Backwater\_Under\_Duck](https://boards.straightdope.com/u/Backwater_Under_Duck)\ **Post date:** [July 13, 2016, 12:43am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/26 "2016-07-13T00:43:10Z")
When you are streaming from the internet, the content is coming as you ask for it. An ad might play before the content, or in the middle of it, but it is always in sync with what you want to be viewing. Cable, on the other hand, is on a schedule. You can block every ad that plays, but you’re still going to have to wait three minutes, or whatever schedule your broadcaster (is that still a word?) engineered for your show to start up again. It takes physical effort to get around that, that is, recording your viewing several hours in advance. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [July 13, 2016, 12:46am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/27 "2016-07-13T00:46:24Z")
> [@Joey\_P](#): > > There is, though. Well, kinda, I’m not sure how it’s implemented. With Tivo some shows (maybe about 20-30% of them) are tagged with the word SKIP. On those shows when a commercial starts you can press a button on the remote and the jumps right to where the commercials end. (If you were to hit the button again, it would go to where the next set of commercials end, it’s the _end_ of each commercial segment that the skip function looks for). However, I have no idea who puts that bit of code in the show. Could be someone at TiVo hand programming, could be the broadcaster/network, could be the studio, I have no idea. No matter who does it, I’m guessing everyone involved has to give their okay, probably including the advertisers. Tivo actually hires people to watch the shows and record where the commercials are. That’s why the feature is available only on certain networks and only during evening prime time. It is available on the Roamio and Bolt models. The commercial markers are downloaded to your Tivo via the internet after the show airs. ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [July 13, 2016, 12:59am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/28 "2016-07-13T00:59:06Z")
> [@Backwater\_Under\_Duck](#): > > When you are streaming from the internet, the content is coming as you ask for it. An ad might play before the content, or in the middle of it, but it is always in sync with what you want to be viewing. Cable, on the other hand, is on a schedule. You can block every ad that plays, but you’re still going to have to wait three minutes, or whatever schedule your broadcaster (is that still a word?) engineered for your show to start up again. It takes physical effort to get around that, that is, recording your viewing several hours in advance. I have cable, and I would rather hear silence, or switching to another channel instead of the stupid commercials that always air. ---
**Author:** ![Shalmanese](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)\ **Post date:** [July 13, 2016, 2:46am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/29 "2016-07-13T02:46:05Z")
Nobody’s mentioned the real reason which is, on the internet, ads are served from separate servers from content and/or located in their own divs/iframes. This makes it very simple to create a list of programmatic filters that cleanly separate out ads from content and only display the latter. With TV, content and ads are intermingled into the same datastream with no metadata to label which is which. This means any ad blocking would have to automatically derive this data in real time across a wide range of content. This is by no means impossible but it doesn’t appear the market is large enough for such solutions to exist. Notice also that there doesn’t currently exist a solution to block podcast ads or ads that are integrated into online video by the creators (as opposed to the ones inserted by Youtube which are easily blocked). In all cases, the cause is the same, when ads and content are intermingled, blocking them becomes significantly more difficult and we don’t bother. ---
**Author:** ![Jragon](https://avatars.discourse-cdn.com/v4/letter/j/e19b73/32.png) [@Jragon](https://boards.straightdope.com/u/Jragon)\ **Post date:** [July 13, 2016, 2:55am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/30 "2016-07-13T02:55:13Z")
> [@jtur88](#): > > So, as I understand it, then, there is no embedded signal coming down the cable that can be read as the start or stop of an ad, so nothing for an ad-blocker to use to recognize a commercial. Right? > > And when I play a Youtube video, there IS a signature in the ads that AdBlock can recognize. How hard can that be to defeat? It’s actually not all that hard to foil adblock on video streaming sites, the fact that Youtube doesn’t is more an unwillingness to lose even more goodwill than they already have than anything else. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [July 13, 2016, 3:51am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/31 "2016-07-13T03:51:01Z")
Meanwhile, I have my own invention in mind – The Mute Pillow. Rather than have to sit with the remote in your hand, and find the mute button for every break, design a cushion on the sofa that has a bladder in it, so if you give it a light thump., air pressure activates a mute button signal. Commercial comes on, tap the pillow. Commercial ends, tap it again. Feel welcome to patent it, i don’t have the patience or ambition. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [July 13, 2016, 4:09am UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/32 "2016-07-13T04:09:55Z")
> [@Amateur\_Barbarian](#): > > There’s probably no reliable technique for zapping and skipping commercials on cable, short of a very powerful “fingerprint” scanner with a continuously updated database. Good luck. Seems like it would be possible to build an effective **ad-skipper-box** that depended on the viewer to identify the ads. Just have them press a button to identify the current video feed as a commercial the first time you see it – then the box skips forward 29 seconds, and records the last few seconds as a ‘fingerprint’ to identify this ad, and automatically skip it the next time it appears. This system works pretty well online: there is software where the user identifies an email as ‘junk’ or ‘spam’, and then the system automatically marks future identical or similar emails. Seems like it could work equally well for TV. Memory is cheap enough that you could easily save 1-2 seconds of the start of many ads, and skip them automatically. TV commercials seem to repeat so often that you could eliminate a whole lot of them this way. And it would be self-correcting – when you run out of space to remember new commercials, the system could erase the oldest/least repeated one to free up space. Online, there are even systems that summarize the ‘votes’ from many email users to identify junk emails quickly. A similar system could be setup to email you a daily file of the most frequent TV commercials currently. (Probably would have to have separate versions for each major TV market, to catch local commercials, too. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 13, 2016, 12:36pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/33 "2016-07-13T12:36:08Z")
Following up on the ReplayTV method and another one: I have a (still working) ReplayTV. (Bought second hand and used a free program guide.) When I used it I tried the ad skip at first. It didn’t work all that well. I also have tried the ad detection tool in the VideoRedo editing program. It is wrong more often than it’s right. Detecting ads is hard. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 13, 2016, 12:54pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/34 "2016-07-13T12:54:08Z")
> [@Slash1972](#): > > The ad-block device would be a separate device that sits between the cable box and the TV so HDMI could still be used. As others have said, the HDMI interface is part of the hardware DRM for many video sources, and only something that licensed the encryption capabilities would work - and I doubt a company would be allowed to license the code etc. for the purpose of “breaking” the system. > [@Dewey\_Finn](#): > > You can use composite cables rather than HDMI but my understanding is that you’re not going to get a full HD signal unless you use HDMI cables. This. While you can get around HDMI with enough gear and patience, it’s reached the point where most video stacks are all-HDMI all the way through, which is both a blessing (gad, it’s easy to manage) and a curse (you’re slaving yourself to the content as the providers want you to see it). Trying to fingerprint ads would be an endless exercise in frustration. The only ones it would catch would be long-running ads, and the practice has been to stir them around frequently and have several variations running simultaneously. You can’t underestimate the forces involved. Ads are not casually tacked onto the mix - they _are_ the mix. “Television is an advertising medium that occasionally shows less overtly-commercial content.” ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [July 13, 2016, 4:01pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/35 "2016-07-13T16:01:39Z")
> [@Amateur\_Barbarian](#): > > As others have said, the HDMI interface is part of the hardware DRM for many video sources, and only something that licensed the encryption capabilities would work - and I doubt a company would be allowed to license the code etc. for the purpose of “breaking” the system. I wasn’t aware that the encryption system was designed to facilitate advertisement watching. I thought it was to prevent piracy? Why would muting a TV during ads “break” the system? > [@](#): > > Trying to fingerprint ads would be an endless exercise in frustration. The only ones it would catch would be long-running ads, and the practice has been to stir them around frequently and have several variations running simultaneously. Funny that I’M able to fingerprint ads and switch to a different channel, so it’s definitely possible. ---
**Author:** ![Skald\_the\_Rhymer](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Skald\_the\_Rhymer](https://boards.straightdope.com/u/Skald_the_Rhymer)\ **Post date:** [July 13, 2016, 4:06pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/36 "2016-07-13T16:06:32Z")
> [@Dewey\_Finn](#): > > If, hypothetically, ESPN knew that Comcast was offering its customers the option of not seeing the commercials, ESPN would demand even more than it already does for Comcast to carry the ESPN channels on Comcast’s cable systems. The cable channels depend on the advertising revenues to meet their budgets. This. I honestly don’t understand the antipathy towards. I prefer the old model of four 3- d commerical breaks per hour to product placement during the show. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 13, 2016, 4:16pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/37 "2016-07-13T16:16:15Z")
> [@Slash1972](#): > > Funny that I’M able to fingerprint ads and switch to a different channel, so it’s definitely possible. And you probably won’t have to watch many ads during the year you pick up your Nobel Prize for developing a perfect AI. ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [July 13, 2016, 4:21pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/38 "2016-07-13T16:21:16Z")
> [@Amateur\_Barbarian](#): > > And you probably won’t have to watch many ads during the year you pick up your Nobel Prize for developing a perfect AI. I actually plan to pay poor 3rd world country citizens $1 a day to watch whatever I’m watching, and mute the TV when an ad comes on. No AI necessary. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [July 13, 2016, 4:37pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/39 "2016-07-13T16:37:46Z")
But then the peasants will revolt and come the revolution, there won’t be no more TV. Seriously, trying to develop even a 90% effective ad-zapper for all cable channels is a far harder job than developing a good anti-malware package. For one thing, the channels can do a dozen things to baffle such a system and they are all legal - you can’t force them to put a black frame in between content and ad, for example. And since the system exists almost entirely to deliver ads to eyeballs, you’re fighting the entire structure of content-makers, advertisers, technical development, cable delivery, consumer equipment design and standards… everything. I’d bet one wooden nickel that it’s not possible to build an ad-zapper (that takes any desired action such as muting, blanking or changing channels when an ad is detected) that: [ol] [li]Works in realtime. (ANYTHING can be done in post-processing or with long enough delays.)[/li][li]Correctly detects an ad 95% of the time.[/li][li]Correctly detects the end of the ad break 90% of the time.[/li][li]Does not false-detect more than once per broadcast hour.[/li][/ol] …and those standards are so lenient that most viewers wouldn’t find them sufficient for pleasant viewing. Exponential curve from there towards “perfection.” ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [July 13, 2016, 4:59pm UTC](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733/40 "2016-07-13T16:59:38Z")
Does your definition of “ad-zapper” include a system that includes a human being? [Previous page](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733.md?page=1) [Next page](https://boards.straightdope.com/t/why-no-ad-blocking-for-cable-tv/759733.md?page=3)