HDHomeRun image quality issues compared to Channels

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pcrispy
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Joined: Sat Jul 27, 2019 6:39 am

HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sat Jul 27, 2019 6:53 am

I just received my HDHomeRun Scribe Quatro the other day, and trying to make the jump to cord cutting officially for the first time. HDHomeRun GUI is pretty old looking, almost geared more for very little kids in appearance, so I was looking at other options for an actual guide and more up to date GUI. The other issue I found with HDHomeRun's apps was that the output of live and DVR was definitely a 30p look, which made 1080i stuff have jagged edge graphics and a very obvious de-interlaced 30p look (I work for a TV station and have worked in the video world for the past 27 years, currently doing most stuff in 4K 60p) so that was an additional thing I sought out more information about. I tried out Channels on my iPhone and instantly enjoyed the GUI much more, but then when I started watching live TV, I then noticed just how bad the HDHomeRun output was in comparison. Channels is outputting a 60p signal that preserves the smoothness of a live 1080i or 720p broadcast, but then also keeps the graphics smooth and clean. Here are some additional findings when I inspected frames in detail, along with the attached image which shows HDHomeRun on the left, and Channels on the right in each scenario. The channel 13 examples are 1080i, the channel 59 example is 720 60p:

HDHomeRun has 29 pixels of black at the bottom, 0 at the top, 1 pixel on each side
It’s scaled up to 100.3% compared to full size 1920x1080, which also results in a few rows of cropping at the top and bottom

Channels
1-2 pixels of black at the top, 0 at the bottom or sides

Black levels (bottom right corner of sample pic) the Channels App had a Hue, Saturation and Black level of 0, 0, 0 where the HDHomeRun had 293˚ Hue, 11% Saturation and 7% Black levels. Definitely washed out, and also the whites on Channels measuring 99%, the HDHomeRun whites only measure 92%, resulting in the very flat picture.

Anyone else notice how bad HDHomeRun is, or is there any solutions to improve this? Clearly seems narrowed down to the decoder that HDHomeRun is using, so maybe it is what it is and 3rd party is the only real option for retaining a better picture?

https://i.imgur.com/Dmg2IVm.jpg

Image

NedS
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Re: HDHomeRun image quality issues compared to Channels

Post by NedS » Sat Jul 27, 2019 4:18 pm

On some platforms this would be controlled by the "High quality video processing" setting, which will use a higher quality deinterlacer and will preserve 60 fps on channels that are using 60 fps. Offhand I forget if iOS automatically uses the higher quality deinterlacer in our video player by default, but it should be preserving 60 fps as long as hardware decoding is being used. Perhaps something is being incorrectly detected in the app and it is falling back to software decoding.

If I could get you to do the following, we could get some more insight onto why this is happening:

1. Open the HDHomeRun app

2. Open up the Recorded/Discovery/Tasks screen and tap on the gear icon in the top righthand corner.

3. Enable the "Send diagnostics information" option.

4. Go back to live TV and watch a channel with live content for a few minutes,

Then reply back to this thread with the Device ID printed on the bottom of your HDHomeRun device, and we will check the logs.

pcrispy
Posts: 35
Joined: Sat Jul 27, 2019 6:39 am

Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sat Jul 27, 2019 4:35 pm

Thank you for the help. I turned that on and then watched 5 minutes or so. Device ID is 15203D7F

pcrispy
Posts: 35
Joined: Sat Jul 27, 2019 6:39 am

Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sat Jul 27, 2019 4:46 pm

Also, for what it’s worth, the output looks the exact same on all of my Fire TV units. I have 2 Fire TV 4K pendant style, and 2 Fire TV 4K Sticks. I went and checked all of them just to see. I don’t have the paid Channels viewer for the FireTV so I can’t see if it looks super good on those like it does on my iPhone. But HDHomeRun definitely is disappointing on all options right now. Would this setting also affect the black level, scaling and cropping like I also mentioned?

NedS
Silicondust
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Re: HDHomeRun image quality issues compared to Channels

Post by NedS » Sat Jul 27, 2019 4:48 pm

Ah, I'm such a bone head, I forgot that our iOS app does software decode MPEG2. In any case, I will inquire about your case with our developers and see what's going on.

pcrispy
Posts: 35
Joined: Sat Jul 27, 2019 6:39 am

Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sat Jul 27, 2019 4:53 pm

Thanks for the quick reply. Since I did another post right before you replied, I’m not sure if you saw it. Regarding the fact that all 4 of my FireTV devices have the exact same image quality and deinterlaced look. Any thoughts on that?

gtb
Expert
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Re: HDHomeRun image quality issues compared to Channels

Post by gtb » Sat Jul 27, 2019 6:08 pm

pcrispy wrote:
Sat Jul 27, 2019 4:53 pm
Any thoughts on that?
Does the same thing occur on the nVidia Shield (which exports hardware decoding options to the applications)?

pcrispy
Posts: 35
Joined: Sat Jul 27, 2019 6:39 am

Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sun Jul 28, 2019 7:19 am

After doing more testing today, I need to correct my findings concerning the Fire TV 4K pendants that I have. They appear to be transcoding in the higher quality mode for live and DVR. I discovered that while I don't own the Channels live tv app, I can get the free Channels DVR app not eh Fire TV to play the livestream by opening the Channels app on my iPhone and choosing to watch it on one of my Fire TVs instead of my phone. That makes the Channels DVR app go into a live tv mode (maybe a glitch?) but while doing that, I was able to confirm that Channels looks perfect for 720p and 1080i live tv channels. When I tried HDHomeRun again, I still get the ugly de-interlaced 30p/jagged edges on the iPhone, and also on both of my Fire TV Sticks 4K, but the older 4K pendants do play in the smoother 60p without the jagged graphics. The Channels app still somehow produces a slightly better image overall, but they are much closer and the HDHR is actually acceptable. I know that a while back the 4K Fire Sticks had some interlacing stuff going on, but I thought that was already solved now. They are fully updated, so I'm not sure what else there would be to do. Any suggestions?

tmm1
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Re: HDHomeRun image quality issues compared to Channels

Post by tmm1 » Sun Jul 28, 2019 9:25 am

There was some similar discussion of a quality regression in the HDHR iOS app here: viewtopic.php?f=119&t=71733

pcrispy
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Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sun Jul 28, 2019 10:09 am

Thanks for the link. That’s exactly the same stuff that I’m seeing. On the 4K Fire TV Sticks I don’t see the washes out color space so much, but definitely see low quality de-interlacing and only 30p frame rate.

jasonl
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Re: HDHomeRun image quality issues compared to Channels

Post by jasonl » Sun Jul 28, 2019 12:56 pm

The Fire TV Stick 4Ks were switched to software decoding of MPEG2 because the hardware decoder was broken from release and Amazon just released the fix a couple weeks ago. I suppose it's had enough time to be pushed to all devices and so we can re-enable hardware decoding. I'll check with the development team.

pcrispy
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Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Sun Jul 28, 2019 1:16 pm

Awesome news! Thank you!

pcrispy
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Joined: Sat Jul 27, 2019 6:39 am

Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Tue Jul 30, 2019 3:26 am

Just for kicks I used VLC to open the HDHomeRun tuner on the local network, chose a channel, and the image quality from that on iOS and FireTV is the best of any. Top HDHR, middle Channels, bottom VLC
Image

pcrispy
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Re: HDHomeRun image quality issues compared to Channels

Post by pcrispy » Wed Jul 31, 2019 2:12 pm

jasonl wrote:
Sun Jul 28, 2019 12:56 pm
The Fire TV Stick 4Ks were switched to software decoding of MPEG2 because the hardware decoder was broken from release and Amazon just released the fix a couple weeks ago. I suppose it's had enough time to be pushed to all devices and so we can re-enable hardware decoding. I'll check with the development team.
Any update from the development team on when they can push the hardware decoding update?

jasonl
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Re: HDHomeRun image quality issues compared to Channels

Post by jasonl » Wed Jul 31, 2019 6:36 pm

The change has already been committed. There's an unrelated decoding bug we're also working on, and when that is completed we expect to release an update for all platforms. I'm hoping it will be submitted by the end of the week, but we'll see.

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