[mythtv-users] Various questions

kteague at speakeasy.net kteague at speakeasy.net
Thu Sep 22 19:00:47 UTC 2005


Good day Ladies and Gent's,

Long time lurker, first time poster with a few questions up my sleeve regarding hardware requirements for my type of setup.  

Service Provider: DirecTV (from here on, referred to as D*)
Video Format: NTSC
Receiver: Any HD capable D* receiver
Television: Westinghouse LVM-37w1

1. From what I've gathered, since the DirecTV receivers have tuners in them, I do not need a tuner for my MythTV box.  Is this correct?

2. I would like to record HD stuff, however, it appears that the only way to do this is via encoding with CPU overhead (no hardware encoders), as there are no video capture cards (supported under Linux) that can perform hardware HD encoding.  I did some reasearch on chipsets used on the Hauppauge PVR-500, and it appears the maximum encoding resolution they support is SD.  Now this is where it becomes very confusing.  The chipset used on the card is a Conexant CX23416.  The product brief (http://www.conexant.com/servlets/DownloadServlet/102074B.pdf?FileId=996) states that it supports hardware encoding of 720x480, yet, just below that, it says it also supports "HDTV MPEG Capture".  So, does this card also perform hardware encoding of 1280x720, or even 1920x1080?

3. Are there any hardware encoding cards supported under Linux to encode the captured streams to MPEG4?  If so, does MythTV support this?  I know there's a Matrox USB device that can do this, but I would prefer something internal to the PC.

4. Output -- does MythTV output through the capture card?... or through the video card?... or do I have my choice?  I would like to use DVI and keep everything in the digital domain.

5. With the front end/back end arch., where are the encoder cards installed?  In the front or back end?

6. With the FE/BE arch., can the programs be recorded on the FE, then x-fer'd to the BE when the program is done recording?  I fear that a temporary network failure could disrupt a program recording.  Having it record on a small FE box, then x-fer'd later (or in chunks as the program is recording) to the BE, it can take advantage of resuming a failed upload to the BE.  Streaming the data has its limits.

7. With the video scaling capabilities, could I get MythTV to constantly upscale all signals to 1080p?  For example, lets say I'm watching SDTV (480i), will it upscale that to 1080p?  Then, lets say I change to a channel that's outputting HDTV (720p or 1080i), will it automatically know to upscale those to 1080p?... or will I have to fiddle with MythTV each time I switch channels that output different scan rates?

I think that's it for now.  Please be nice to this newbie :-)  I've been trying to do my research on this project between working 2 jobs and school.  Thanks!

- Ken






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