Basic setup to record 1 HDMi channel off STB

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benway lbd
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Basic setup to record 1 HDMi channel off STB

Post by benway lbd » Fri Oct 01, 2021 2:24 am

I have a very basic question, I've searched the MythTV forums & other places without finding an answer so I'm hoping to get it here. I want to setup a basic system to record a single HD channel from a Cisco STB. Basically, I just need to be able to record & replay 1 channel at a time off the STB. MythTV seems like overkill for these simple requirements but I wanted to check since I've not found anything else that seems to be what I need.

This is for outside on a covered porch, I just want to be able to pause, rewind & record some football/basketball games off the STB. I have an old Intel D2550 mini-ITX box with 2G RAM & WD Black 1TB drive for which I'd add an HDMI-capable USB capture card.

Thanks for any info.

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heyted
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Re: Basic setup to record 1 HDMi channel off STB

Post by heyted » Mon Oct 04, 2021 12:37 am

A Hauppauge HD-PVR 1212 can be used to record from some Cisco set-top boxes, but it does not have HDMI. If this is Comcast, consider a cablecard tuner.

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benway lbd
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Re: Basic setup to record 1 HDMi channel off STB

Post by benway lbd » Tue Oct 05, 2021 4:43 pm

Thanks for the pointer to the Happauge 1212, but unfortunately my TV does not have a component video input (only HDMI & composite). I have Suddenlink with a Cisco 4642HDC STB.

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paulh
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Re: Basic setup to record 1 HDMi channel off STB

Post by paulh » Wed Oct 06, 2021 10:30 am

It's a bit of a touchy subject because while recording from HDMI is probably morally OK because you have paid for the service and hopefully you will keep the recordings for your own use but legally it is not, certainly in the USA because whether you are aware or not it circumvents the encryption that is there to prevent you doing what you want to do :roll:

I think at the end of the day it's should be your decision whether you want to take the risk. While this does not do exactly what you want you can get some pointers from here https://github.com/bennettpeter/MythTV-LeanCapture

So basically you need to setup an External Recorder https://www.mythtv.org/wiki/ExternalRecorder

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Re: Basic setup to record 1 HDMi channel off STB

Post by benway lbd » Wed Oct 13, 2021 2:57 am

Thanks for the info. Though I said record in my original post what I actually meant was just pause & rewind on a single channel, though perhaps from a legal perspective they are the same thing if using HDMI? I'm not trying to get around any copy protection to make recordings, I basically want to be able to pause & do my own instant replays in our outside TV setup. I have an old Tivo Series 3 with cable cards inside that can be used to record whatever I want to keep. But I don't want to pull the Tivo out of the home theater setup to just do those basic pause/rewind functions, it's not like we're watching TV outside every day.

The Cisco STB has component out, so using something like the Happauge 1212 I guess I could could use a component-HDMI converter to get back into the TV HDMI input. That was what I was trying to figure out, it seems like I'm not needing most of the awesome MythTV functionality, I just want pause & rewind :-)

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paulh
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Re: Basic setup to record 1 HDMi channel off STB

Post by paulh » Thu Oct 14, 2021 4:50 pm

Recording from component is different than recording from HDMI since it does not circumvent any copy prevention so I believe you are OK there but I'm not a lawyer. Your providers TOS may still prevent you from doing what you want but who reads those anyway :) I know jpoet a fellow dev used a HD-PVR2 that can record component and HDMI with MythTV viewtopic.php?f=2&t=2530

The HD-PVR wont allow you to record from HDMI if it is encrypted using HDCP though unlike the Chinese USB capture devices that don't bother with technicalities like that they just strip the encryption regardless (it's that part that is 100% illegal in the USA). You may also find HDMI splitters from China that do naughty things like removing the HDCP ;)

One thing to note is the HD-PVR2 re-encodes to H264 I think which is good but it does introduce significant delays of several seconds which can be annoying when watching live tv and want to channel hop.

The Chinese USB capture devices I've seen don't re-encode they just give you the raw frame data which means the amount of data to move is enormous for a HD picture. Peter told me his device can encode to MJPEG which is better than nothing but I've not found one myself that does that.

Peters LeanCapture solution uses his powerful backend machine to re-encode to H264 in realtime which does require a fairly powerful machine to do it and get reasonable quality. If you are not going to keep the recordings and just want a temporary cache you can pause and rewind then I would use something a little less cpu intensive like a NUT container with huffyuv video encoding. It does require more disc space but is quick to encode and decode so less latency and requires very little cpu to do it.

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