HDHomeRun CPU power
Submitted by k7_madman on February 28, 2009 - 6:20pm
I would like to get a HDHomeRun for over the air HD. I read that it does not have a hardware encoder build in, does this mean it takes a lot of CPU power to record HD video?
There is no encoder because
There is no encoder because digital signals come encoded. I dont this there is a resource penalty for using a HDHomerun vs an internal card. The hdhomerun is great because you get 2 tuners and it does unencrypted QAM channels.
HD Playback is resource intensive no matter what. If you have the right video card and configuration the demands are lower not by a whole lot. Check out the wiki.mythtv.org wiki for some examples of hardware / video card you will need.
What kind of out put do you
What kind of out put do you get with HDHomerun 1080i? What is the file type the recordings come in as (.mpg)? Does it take a lot of network bandwidth when in use?
The created files are mpg.
The created files are mpg. I have a 100mbit network and dont have any bandwidth problems even when using a remote frontend. Even when recording both streams.
What resolution does it
What resolution does it capture at? Do you get videos at 1080i or 720p?
The HDhomerun records
The HDhomerun records whatever is broadcast. If it's a 1080i signal, then it records it at that resolution (1920x1080). If the broadcast is 720p, then that's what gets recorded. Like was mentioned previously, the HDhomerun does not do any encoding or transcoding, which is also why it takes almost zero CPU to record. It just forwards on the bits as it receives them from the cable or antenna.
-darren
Ok thanks, I think I will
Ok thanks, I think I will buy one. I wanted an HD tuner, this one seemed the best but it cost about $150, which is more then the cost of my mythbox parts put together :P I was just hoping I didn't need to upgrade everything to record HD. I was also worried about the broadcast flag and how that would effect resolution.
I have never encountered
I have never encountered anything with a broadcast flag, so I dont know how it would be handled.
There are things in a system that could affect your perforamce such as video and processing power.
I would recommend downloading some of these samples to see how hd playback will look on your system.
http://x264.nl/h.264.samples/
Antenna or cable HD
Antenna or cable HD broadcasts are *not* encoded with h.264, so those samples will not be indicative of whether or not your system will be able to play content recorded with the HDhomerun. mpeg2 (which the HDhomerun records) is far less processor intensive than h.264.
Just as a benchmark, my old 32 bit single core athlon 3200+ would play back 1080i content from the HDHomeRun, but just barely. I had to make sure I didn't have any other jobs running in the background.
-darren