Introduction
During the Christmas holiday I got a brain wave that it would be nice if I could record television in Japan and watch it at home. In the past I had a recording system based on freevo and that worked quite nice. I should be able to have something similar when it was possible to install a small ARM based linux system back in Japan.
The figure below gives an idea about what I want to make:
Picture will follow!!
I am already the owner of a Beagleboard XM, a Pandaboard and a Raspberry Pi. All three were nice to play with, but not so suited for this new project. So I started to look for a board that would be more suited for this project.
Board comparison
I am looking for the following:- A separate network, usb and preferably Sata interface to prevent bottlenecks during recording and streaming/copying the contents.
The Beagleboard, Pandaboard and Raspberry Pi do not score well on this point; the network and USB are connected over the same bus interface to the soc. And this proved (with old kernels) to be a clear bottleneck. Also no sata interface available. - A bit horsepower to encode the recordings in a smaller format.
This disqualifies the Beagleboard and the Raspberry Pi. Both have some support from their DSP or graphical coprocessor, but that is not enough to re-encode movies from 1080p to something smaller. - A convenient form factor so that I can build it in a need box.
This means that the board should be small and the connectors should be placed in a smart way. The Pandaboard has for instance the disadvantage of a large combined connector for ethernet and USB, which makes this board very high
Someone has already spend some time on a nice overview of different development/hobby boards. This overview you can find; here. The table below summarises the comparison on the for my project important points:
Board name: | Pandaboard | Cubieboard2 | Odroid-U3 | Wandboard Quad |
Processor: | TI OMAP4430 | Allwinner A20 | Samsung Exynos4412 | Freescale i.MX6 quad |
Architecture: | Cortex-A9 | Cortex-A7 | Cortex-A9 | Cortex-A9 |
Cores: | 2 | 2 | 4 | 4 |
Frequency: | 1GHz | 1GHz | 1.7GHz | 1GHz |
Memory | 1Gbyte | 1Gbyte | 2Gbyte | 2Gbyte |
Sata: | No | Yes | No | Yes |
USB Host: | 2 + 2 | 2 | 3 | 1 |
Ethernet: | 10/100 | 10/100 | 10/100 | 10/100/1000 |
Shop: | digikey | Conrad | Hardkernel | Denx-cs |
Price: | 150 Euro | 75 Euro |
110 Euro | 118,94 Euro |
Advantage: | Already available (no additional cost) | Relative cheap and with Sata. Sold by Conrad | Very fast | Fast and Sata |
Disadvantage: | Ethernet and USB over the same channel proved already to be a bottleneck in the past. Memory subsystem not that good. SD card and USB are slow. Relative expensive compared with the others. |
Except for the interfacing not really an improvement: Cortex-A7 is less powerful than Cortex-A9 and the Pandaboard was already slowish | Must come from Korea which adds time and costs (shipping + tax) | (Passive) USB hub needed A bit unknown... how will the support be? |
The table above shows clearly that of the four boards the ODROID-U3 is the most powerful one. Therefore it would be the most suited to decode /encode the video data in a smaller format. However getting this board in time from Korea can be a problem. The Wandboard is a good runner up in terms of price and performance. I have ordered both and will see if I get the Odriod board in time or not.
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