In all HD-PVR firmwares later than 1.0.3.53, AC-3 multiplexing via S/PDIF is available, allowing one to multiplex the original 5.1 channel audio track into the captured stream. HD-PVR users are encouraged to contribute to the page to ascertain real-world playback requirements without VDPAU or some other form of hardware-accelerated playback with MythTV. HD Playback Reports acts as a repository for processor requirements to play high definition material. Hauppauge recommends a dual-core CPU as a minimum if not using VDPAU a frequently cited minimum for medium-bitrate H.264 playback is a Core 2 Duo 1.8 Ghz processor. By contrast, even systems which easily play back US broadcast/cable MPEG-2 HD are likely to fail altogether when playing back a recording from the HD-PVR without hardware acceleration. Fortunately, using VDPAU or VDA video card hardware acceleration makes H.264 playback easy. The tradeoff is that decoding H.264 material is very processor-intensive. The HD-PVR uses modern codecs capable of exceptional compression rates at excellent quality. A 13.5 Mb/s H.264 stream is roughly equivalent to a full-channel-bitrate MPEG-2 recording at approximately 19 Mb/s.
The H.264 video codec is, bit-for-bit, up to 40% more efficient than the MPEG-2 video codec commonly used in US HDTV broadcasts today. Capture resolution is dependent on the source (ie 720p video will be captured as 720p, 1080i as 1080i, etc.) but the bitrate is user-selectable from 1 megabit/second up to 13.5 megabits/second. The streams are multiplexed into a slightly modified MPEG-2 Transport Stream container.
The HD PVR captures at resolutions from VGA/D1 (480i) up to 1080i, and encodes the component inputs in real time using the H.264/MPEG-4 video codec and the AAC audio codec. Prior to this device, component capture devices were cost-prohibitive and were not directly supportable within Linux. In other words, since component video is not and cannot be encrypted, previously uncapturable HD sources such as satellite and premium television will now be fully accessible in MythTV. The HD-PVR is a highly popular capture device because it captures video via component output, permitting the user to capture high-definition video from most sources and without concern for encryption. The HD-PVR is a USB device that captures the component video outputs and analog/optical audio outputs of any consumer device (including cable/satellite set-top-boxes, HD disk players, video game consoles, and various other home media devices).
The Hauppauge HD-PVR is the first consumer-level analog HD capture device available.
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