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TV upgrade -- HDHomeRun and MythTV 0.22 - Alex Belits
TV upgrade -- HDHomeRun and MythTV 0.22
After The Great TV Transition To Digital, Comcast for a while kept transmitting everything in analog NTSC, so I was able to use my Hauppauge WinTV PVR-250 for cable, and occasionally watched over-the-air ATSC with HVR-950. It was clear that this was not going to last, and recently all but few NTSC channels disappeared. On top of that, when HVR-950 didn't get a sufficiently strong signal or was otherwise confused, a combination of its hardware, driver and MythTV 0.21 ended up in some weird state that prevented all further tuning until full driver reload, so over the air reception was quite far from the painless experience that I remembered from pre-cable, pre-digital days. Upgrade to MythTV 0.22 gave me some improved HDTV output modes, but didn't do anything to reliable ATSC reception, and definitely didn't turn PVR-250 into a digital decoder -- something had to be done. My 40th birthday was an acceptable excuse to buy another device, so after some research I went to Fry's and brought home HDHomeRun -- a networked dual-tuner digital TV receiver.

Not surprisingly, installation and configuration were quite painless -- receiver got its address from DHCP, MythTV detected the receiver and its two tuners, ran a scan on both, and found a bunch of channels. Just as not-surprisingly, SchedulesDirect produced a channels list full of mis-identified channels (apparently radio stations that were recognized as TV), so the list required some tweaking before becoming usable.

The surprising part was playback. For a completely unrelated reason I have recently upgraded my NVIDIA graphics card, and the new card supports VDPAU. Before installing HDHomeRun I have spent some time tweaking MythTV to make HDTV play on a 1680x1050 monitor with my old AMD Athlon XP 3200+ and HVR-950. In the end everything up to 720x576 was set to ffmpeg decoder, Xv output, Yadif deinterlacer, denoise3d filter, everything above -- NVIDIA VDPAU, Temporal deinterlacer. Most channels played smooth, however it seemed like the time spent getting the high-resolution frames from HVR-950 was sufficient to cause some choppiness -- or maybe it only looked like that due to some dropped or corrupt data because I only tested it with over-the-air reception. With HDHomeRun this problem disappeared -- flawless playback on cable channels regardless of resolution, occasional visibly corrupt frames on some over-the-air channels, but no choppiness.

For some reason closed captions (and only closed captions, not other forms of overlays) on some resolutions cause massive slowdown and dropped frames. Low resolution (with all-software decoding and Xv output) is fine, high resolution (hardware decoding and high-resolution overlay) is fine, medium resolution (apparently higher-resolution text overlay on lower-resolution hardware-decoded video) has problems. Other than that, I have a fully-functional TV and DVR that receives cable and over-the-air TV, on a box with Athlon XP 3200+ CPU and a five years old motherboard.

Obviously, the whole thing only works with non-encrypted channels -- if by any chance Comcast will decide that they should DRM the Hell out of their network, everything will be broken again. Hopefully sanity will prevail, and the amount of breakage that it would inflict on all other existing subscribers will keep them from going into that direction. PVR-250 still receives some NTSC channels, and HVR-950 is still connected for its analog video input and may potentially be used as a backup tuner -- if I (or driver developers) will find out how to keep it from getting stuck.

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j_b From: j_b Date: November 30th, 2009 06:12 pm (UTC) (Link)

What programs do you watch? :)
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abelits From: abelits Date: December 4th, 2009 03:28 am (UTC) (Link)
Pretty much what you would expect a nerd like myself to watch -- ST:TOS/TNG/DS9 reruns, cartoons/anime on Adult Swim, occasionally South Park, Doctor Who (before and after the sixteen years gap), even more occasionally public TV documentaries.

Though it may look like strong preference for escapism, I think that it's more based on my idea that when anything fictional on TV pretends to reflect anything in modern real life or 20th century history, it ends up serving such a soup of stereotypes, it would be better if it didn't pretend doing so in the first place.
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raider3 From: raider3 Date: December 1st, 2009 02:40 am (UTC) (Link)
Wow... Sorry you're still using Comcast. (Wouldn't hold my breath that they don't DRM their output eventually.)

It's nice to see we've got monitor resolutions in common. I use a 1680 x 1050 myself, and I wouldn't go back to 1024 x 768. ^_^; One of these years I'll go to 1080 vertical.

Glad you're having better luck with over the air than I am. I got one of those damn USB stick ATSC receivers from Pinnacle before they handed off to another company and it's damn near unreliable unless I'm located outdoors or within the closest city to the transmitters.
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abelits From: abelits Date: December 4th, 2009 03:35 am (UTC) (Link)
Glad you're having better luck with over the air than I am. I got one of those damn USB stick ATSC receivers from Pinnacle

Hauppauge HVR-950 is a stick, and it's not really that bad -- my problems with it are mostly with how drivers and MythTV handle error recovery. HDHomeRun never gets stuck, however it still sees dropped data on some channels when connected to my "rabbit ears" antenna.

before they handed off to another company and it's damn near unreliable unless I'm located outdoors or within the closest city to the transmitters.

It helps being located right across the bay from a giant TV tower on a huge hill. Digital TV transition would be less of a pain in the ass if they made sure that new transmitters actually can be heard by people who had usable analog signal.
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abelits From: abelits Date: February 10th, 2011 04:39 pm (UTC) (Link)
Die in a fire, spammer!
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