Hardware Requirements

• A TV card

• MythTV is a software video encoder, which means that it uses a fairly generic "dumb" video capture card to get frames of video, encodes them using the CPU on your motherboard and writes them to disk. High-end video capture cards and devices like the Tivo and RePlay have dedicated encoder chips which use specialized hardware to convert the video stream to the MPEG-2 format without using the motherboard CPU. The main CPU has the responsibility of running the Operating System and reading and writing the encoded frames to the disk. These tasks have fairly low CPU requirements compared to encoding video, which is why a device like a Series 1 Tivo can run with only 16MB of RAM and a 54Mhz CPU.

• There are many variables that go into the question: "How fast a CPU do I need to run MythTV"? Obviously, the faster your CPU, the better your experience will be with MythTV. Performing the "Watch TV" function, where the CPU is both encoding and decoding video simultaneously to allow Pause, Fast Forward and Rewind functions for live TV requires more CPU then just encoding or decoding. MythTV also supports multiple encoder cards in a single PC, thereby increasing the CPU requirements if you plan on simultaneously encoding multiple programs.

• Here are a few data points:

• A PIII/733Mhz system can encode one video stream using the MPEG-4 codec using 480x480 capture resolution. This does not allow for live TV watching, but does allow for encoding video and then watching it later.

• The developer states that his AMD1800+ system can almost encode two MPEG4 video streams and watch one program simultaneously.

• A PIII/800Mhz system with 512MB RAM can encode one video stream using the RTJPEG codec with 480x480 capture resolution and play it back simultaneously, thereby allowing live TV watching.

• A dual Celeron/450Mhz is able to view a 480x480 MPEG4/3300Kbps file created on a different system with 30% CPU usage.

• NOTE: You must use DMA for hard drive access to prevent choppy or jittery video.