Cord Cutting Surprise

Discussion in 'TiVo Bolt DVR/Streamer' started by k2ue, Jun 12, 2017.

  1. k2ue

    k2ue Retired RF Engineer

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    Today I switched my main home Bolt from Spectrum (formerly TW) cable to OTA. For some time I was unimpressed by the picture I was getting from my Epson 5020UB, and was wondering if it was time for an upgrade. Turns out the problem was TW/Spectrum -- we immediately noticed the OTA picture was sharper channel for channel, and small lettering was much cleaner. This is/was with everything upscaled to 1080p by the Bolt, which is the native resolution of my projector. No going back to cable after this.
     
    jhermit and Fant like this.
  2. jhermit

    jhermit Member

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    I did the same 3 weeks ago and now have the locals from OTA and had the same outcome... better picture quality except for all those crappy 480i channels I now get ;).
     
  3. rpiotro

    rpiotro Member

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    Why is that a surprise? The bandwidth on OTA is potentially much higher that what you get from cable. You have gone from arguably the worst source to the best.
     
  4. aaronwt

    aaronwt UHD Addict

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    UNfortunately in many areas they stuff a bunch of sub-channels on the streams. So the quality isn't as good as it used to be.

    In my area this is the case. I'm still amazed at how great some of my 2001 and 2002 HD OTA recordings look compared to today.
     
  5. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    I just binge watched the entire seasons for The Middle and The Goldbergs over the last couple weeks. As luck would have it I had recorded both series both OTA and from Cable. The cable OTA version not only looked better but it had less glitches. I ended up watching both from the OTA Bolt.
     
    Last edited: Jun 14, 2017
  6. V7Goose

    V7Goose OTA ONLY and Loving It!

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    Huh? If the cable version looked better and had less glitches, why did you decide to watch the OTA versions instead?
     
  7. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    I misspoke. The OTA version looked better and had less glitches.
     
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  8. dougdingle

    dougdingle HD Tech

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    All cable and satellite providers step on the signal somewhat (sometimes a LOT) to compress it even further to squeeze in more shopping and other channels no one watches but who pay for carriage.

    Initially, OTA was around 19 Mbits, a decent signal considering it's mostly 20 year old tech: 8 bit 4:2:0 MPG garbage. Once OTA stations started adding 'side channels', bandwidth had to be taken from the main signal to have those, so the 19 Mbits OTA data rate dropped (in my area) to around 11-13 Mbits, not nearly as robust. And the cablecos and satellite companies still stepped on it to compress it further.

    If you use KMTTG, it has a feature that will tell you what the data rate was for every single recorded show on your TiVo. it's eye-opening, to say the least.
     
  9. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    I compared my Bolt OTA to my Bolt+ and it looks like Charter is lowering the bitrate on all of the channels by 12-15%. So that explains the quality difference I'm seeing. Most of the OTA channels are 13-15Mbps. On charter the highest one is a little over 12Mbps.
     
  10. dougdingle

    dougdingle HD Tech

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    Anything below about 15 Mps will macro block with rapid camera movement, dense moving footage like tree leaves blowing in the wind, and of course explosions. That's the sort of thing that makes the weak compression engines cable and satellite providers use pretty much just break down.

    Some of the stuff coming from Spectrum in Los Angeles is horrific, especially on the pay channels. Watching an action movie (what my wife refers to as 'testosterone flicks') on any of their pay channels requires a suspension of disbelief not only about the content, but the form as well.

    What surprises me more than anything is that the streaming services (who do an infinitely better job on compression and mostly use H.264 instead of MPG on 1080 footage) don't tout that more in their marketing. I suppose it makes no difference on a phone or tablet, but on a 65" OLED that doesn't hide anything the difference in quality streaming the identical show through the Amazon Fire or Roku Premiere+ is quite remarkable.
     
  11. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Well one advantage that streaming services have is that they can pre-encode content. So they can use multi-pass encoding that allows them to more efficiently use the bits they have available. Cable and OTA are both compressing a live stream, so it's a lot more difficult to choose a bitrate that accounts for all types of content.

    What's really funny to me is when customers of ours talk about not wanting to recode something for fear of losing quality. By the time we record stuff it has already been recoded a dozen times so one more isn't going to make a big difference.
     
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  12. dougdingle

    dougdingle HD Tech

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    Between the multi-pass encoding, and using H.264 (or H.265 for UHD), streamers do have a real advantage.

    H.264 is a remarkably good viewing codec, just don't try to do anything with the encoded footage except watch it, as it falls apart at an astonishing rate when manipulated in any way.

    People always look at me funny when I point out that at 15 Mbits/s, you're watching footage that has been compressed a minimum of 100:1 from what dribbled out of the original camera.
     
  13. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    We do a pretty good job of editing H.264 in VideoReDo v5. In v4 we used a technique that was more similar to how we do it with MPEG-2 and it did not work as well. In v5 we use a much more complex method of editing that's a bit slower but produces much more compatible results.

    We're planning on adding H.265 editing in the next major version.
     
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  14. dougdingle

    dougdingle HD Tech

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    My experience with H.264 has been that if I try to do color correction, or speed changes, or keying, or stabilizing, or reframing, or anything similar in, say, Adobe CC AfterEffects or Premiere, my output will be less than pristine. :openmouth:

    I work on short projects, usually work with ProRez 4444 source footage, then output in half sized H.264 for emailing approval copies to clients, and that works well for me. Final approved footage usually gets output in ProRez 422 HQ with a matching H.264 viewing copy for those on weaker machines.
     
  15. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Well compared to a 444 ProRes of course it wont be perfect. Temporal compression uses tricks that depend on human visual perception to work. If you start messing with the frames too much you're going to break that. Heck just the chroma compression of 420 instead of 444 would be enough to mess with color correction and keying, even before you get into the temporal compression part of H.264.
     
  16. dougdingle

    dougdingle HD Tech

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    Agreed. Still, H.264 beats the hell out of MPG visually at identical data rates, which is why (in addition to using multi-pass compression engines) streamed stuff looks so superior to the trash being put out by cablecos and satellite.

    Complaining to either source (as I've tried to do in the past) inevitably results in "But sir, it's digital and so it's perfect! There's nothing we can do to improve it if it's perfect."
     
  17. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    Most streamed content is only about 6-7Mbps so it's significantly lower then most MPEG cable channels. But in reality H.264 provides about a 50% advantage over MPEG-2 when starting with a pristine source and using multi-pass compression. So if it requires 6-7Mbps for Netflix to encode a good quality H.264 file, which is only 24fps, progressive and encoded using multi-pass, then cable channels would need to use ~3x that bitrate to get the same visual quality from a 29.97fps, interlaced MPEG-2 that is encoded live. That's never going to happen. Even if they used the full ATSC bandwidth for a single channel it wouldn't be as good as what Netflix can accomplish with post encode from a pristine 24fps source. They're just playing the odds that most people wont notice or wont care.

    I had hoped that the transition to H.264 at cable systems would improve quality, but they seem to be doing the opposite. Comcast is converting everything to 720p and cramming way to many channels per QAM so that they can dedicate more of their bandwidth to internet and VOD. Quality be damned.
     
  18. atmuscarella

    atmuscarella Well-Known Member

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    I would think the solution to better quality has to start at the content provider. Pick any cable channel you want if they sent a higher bit rate h.264 or h.265 stream to the cable & satellite providers then you could get some higher quality video even if the cable company still needed to compress it some.
     
  19. Dan203

    Dan203 Super Moderator Staff Member TCF Club

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    They send a pretty high quality signal to the MSOs/affiliates. We have a customer who captures the network feeds directly using one of this big dishes and they're typicaly like 30Mbps H.264 4:2:2.
     
  20. osu1991

    osu1991 Well-Known Member

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    I believe it was NBC a few years ago that sent out a 45-50Mbps feed to the affiliates for the Super Bowl. I wish I could put my CBand dish up again but can't at my current home and hate to leave it unattended at lake house, so it stays stored. Going to try and get my 1.2M dish up later this summer. Still lots of legal FTA stuff up there.
     

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