OTA channel surfing is slow because before you can see a picture, first you have to tune the digital signal, then you have to wait for an I frame, plus whatever decoder delay and output image processing. In order to make it better, you really need to three tuners, so you can process the streams of the up and down channels. Random access would still be slow, but oh well.
I imagine cable is pretty similar, but I suspect most cable boxes are more capable than tuners in tvs, so they may be running multiple tuners, and I think there's more of a chance of subchannels being useful, too.
It's your cable box. For many digital channels you are essentially getting streamed VOD and their backend equipment is slow. Modern ATSC tuners are reasonably fast with a clear signal. You can legitimately surf like on analog.
The slowness can also be because the channel you are trying to watch is not even there.
I'm not sure who all is using it now but I used to work on the setup for Switched Digital Video. If nobody in your neighborhood was watching a certain channel, it would stop getting broadcast. That freed up bandwith for other things like internet. Once you would tune to a channel, a request would go to the head-end, it would quicky figure out if the channel is being broadcast in your area. If not, a request would go to the content delivery system to start feeding it to the QAM and then obtain what frequency the channel was on, and finally relay that back to the settop box which would tune and start the decoding process.
Rather impressive tech but again, this would add a bit more latency to that particular channel switching.
Maybe there's not a lot you could have done while keeping the hardware cheap. I can think of a few ways to improve the user experience of channel surfing without waiting for an i-frame every time.
The cheapest would be to just use a constant neutral-grey i-frame whenever the channel flips, and update that until a real i-frame comes along, while playing the channel audio immediately. Ugly video for a second, but high-action scenes fill in faster. I'd bet that most people could identify an already-watched movie or series before an i-frame comes in, at least 80% of the time.
More expensive would be to cache incoming i-frames of channels adjacent to the viewed channel, and use the cached image instead of the grey frame. Looks like a digital channel dropping update frames during a thunderstorm for a second.
Prohibitively expensive (back then) would be to use multiple tuners that tune in to channels adjacent to the viewed channel, and then swap the active video and audio when the channel up or channel down buttons are pressed. Drop the channels that just exited the surfing window, and tune in to the ones that just entered it. Surfing speed limited by number of tuners.
Televisions still don't do this, even after more than a decade of digital broadcast, and multiple-tuner, multiple-output DVR boxes.
slightly offtopic, but something that bugs me about OTA broadcast DTV is the program guide. (I'm in Australia which uses DVB-T, other standards may differ). The guide is so slow to load, regardless of the TV set. It also seems to require the TV to scan each channel to pickup that channel's guide data so you're left with gaps in the guide data until the TV has scanned each channel. It seems like a missed opportunity. If we're going digital, why can't guide data be instantly available for all channels?
The old cable boxes were literally switches, with all channels flowing into the box all the time. Now switching is virtual and done on the server (plus all the software encoding/decoding).
Right now I would be satifsied with at least some caching of the menus, so it doesn't have to pull the data everydamntime I scroll up or down. Come on, it should be able to remember what channels I have for more than 5 minutes in a row.
That's the number one reason I bought one of these HD Homerun cable tuner boxes[1]. Once I have a VLC playlist setup with the stream urls to each channel, switching channels is almost as fast as in the old days of analog cable TVs.
Maybe another 4 hours of work got me a little web application that shows the TV guide information pulled from an API, and is hooked in with the VLC web interface to switch channels with a click.
I still don't understand why they don't stream their channels online. It's fairly cheap to do so, they'd get more viewers (and more accurate data about their viewers), and the only real restriction it would remove is the ability to filter viewers by location, but this can be solved by mailing out postcards or something during registration.
I tried using a usb ota tuner a few years ago, but it was painful. Driver issues, reception issues (in the middle of recordings a lot of times), etc. It really wasn't worth the time.
I think it's difficult. That 100mb of cache has to be streaming in for X amount of shows / channels at once. If you start flipping through it has to cache your current show + some amount of the shows you're flipping though.
It's not always easy to transition an analog UX over to digital and not have it appear slower or worse.
There are set top boxes that have many tuners. The STB uses the extra tuners to anticipate a channel change and tune ahead to the next channel. (Fast Channel switch).
It's less about forgetfulness and more about convenience. The whole "setup an OTA antenna somewhere in/on your house/attic/roof, wire it up to your tuner, scan for channels, learn what direction to point the antenna for which stations, find a DVR that supports OTA", vs load an app, sign in and boom.
I'm a geek so, I'd LOVE to take this step. Unfortunately, I live in the part of the country that has too many mountains to make OTA reception an easy task. I personally live down between two ridges that make it so I'd have to have an antenna 150 feet in the air.
Channels DVR works with quite a few streaming services (via TV Anywhere) and does commercial skip too. I use it with YouTube.TV as well as Philo. My parents also pick up OTA with an HD HomeRun on their channels DVR.
The downside to Channels (and to be fair, exact same with MythTV) is the homebrew nature. I had to set up and maintain it for them. But if you have the means to run one and you like traditional cable channel content still, nothing beats Channels.
They also have AppleTV and Firestick clients further sweetening the deal. It's $80 a year - but if you have dealt with Tivo or any of the other commercial products out there, that's not a lot - and it directly funds development. And development on Channels is very active, as is the dev participation in their forums (always a HUGE plus).
What I'd like is an easy, cheap DVR solution for OTA. Mostly I'd just like to be able to pause and rewind live TV. After cutting the cord, it's like living in the 80s again shouting at family members to be quiet when you need to hear something.
Tivo has a pure OTA model that is a reasonable deal. And their UI still beats the pants off of everyone else. Heck they finally embraced commercial skipping too.
If you don't something cheaper/more DIY oriented I'm really happy with channels dvr. It interfaces with Youtube.TV and many others (anyone who partners with TV Anywhere) and can do Over the Air recording with HD Homerun. What I really like is it provides one unified, central location for the majority of the services I care about.
I grew up with analog televisions - there was no latency and it was very forgiving of atmospheric noise. When I first got Tivo, I thought the latency made it unusable (until I realized that I was no longer flipping channels, but rather navigating to content..)
On the other hand, flipping channels led to serendipitous discovery - a cooking show that I would never have found interesting might spark something, or a news show presenting other points of view.
I still use an over-the-air antenna on a daily basis (and record from it using MythTV with ATSC tuners in a computer). The changeover from analog has been a bit of a give and take.
With analog broadcast, if you were a bit too far away you would still get a fuzzy image and sounds that had some interference with it. Now if you're a bit too far away the picture breaks up and the audio sounds like auto-tune. It doesn't take much of that to make it unwatchable.
On the other hand, when you get a solid signal the picture is amazing versus the standard-def of analog broadcasts. Add to this the benefit of multiple sub-channels on each broadcast channel and you get a lot more watching options.
I've installed an attic antenna and a pre-amplifier that supplies great signal to all coax (CATV) outlets in the house. That hardware cost what 1-2 months of cable TV subscription would have and that was years and years ago.
On balance the digital changeover has been much better in my experience.
Some people can't get a good enough OTA signal for a digital receiver to work. In my previous apartment that was the case even though I was probably only 10 miles away from the stations I cared about. That led me to look into things like Locast and become a donator. It's also super convenient since you can watch things on a phone or tablet. I mainly used it for watching Jeopardy in the kitchen while watching on an iPad.
I'm skeptical also. Do people really want a search driven TV experience? TV is the opposite of the Internet in many ways. I think people want content pushed at them or presented in a buffet style interface. From the demo video Google TV looks to be very focused on search instead. The other thing that made me skeptical was Google presenting the problem of a program being on multiple channels. My cruddy cable DVR was able to figure this out years ago. TIVO has always done a very good job at it. What's the problem there?
These days they should be able to guess what 20 channels you might change to and start recording those in the background.
I've always suspected the reason it's slow is because you press the remote button, the DVR sends that to the provider, the provider has to verify that you can do what you are asking it to do, then a response comes, then the change can start.
I imagine cable is pretty similar, but I suspect most cable boxes are more capable than tuners in tvs, so they may be running multiple tuners, and I think there's more of a chance of subchannels being useful, too.
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