Home Theater

Tom’s Networking, the networking part of Tom’s Hardware, has this round-up/review of 3 devices: ActionTec, Netgear and SMC. The verdict: not so good. A maximum throughput rate of 10Mbps on a device that’s rated at 85Mbps. Hopefully they’ll be able to work out what the constraining factor(s) are.

I just discovered the BBTI AirStar HD5000 (for what it’s worth, the Technisat site looks like it just supports DVB so maybe the BBTI folks really did strike up a deal with them). It comes in both a PCI and a USB version although the USB looks like it’s just a PCI card in a USB-adapted box. From some searches I’ve done, it looks like it’s used mostly by Linux folk. There’s also a support forum for it. You can also get it at CyberStore.com.

I’ve been capturing transport streams from my Motorola DCT-6412 DVR with VideoLAN. Once captured, I’d use something like MPEG2Repair to fix up the stream and I’d see anywhere from about 10 to thousands of errors. Well, last week I began using CapDVHS to capture and my streams have been error-free ever since! CapDVHS doesn’t have any facility for viewing the stream while capturing whereas VLC does. Perhaps, in an attempt to keep the display properly synched VLC drops packets and maybe that accounts for the difference? I don’t know but things run much more smoothly now.

(Just a note on the link to CapDVHS. Here is the original site in Japanese and here it is in English courtesy of Excite.co.jp’s translator; the link I posted above is for a version whose font was changed to make the application more readable. And thanks to this posting in AVSForum for the link to the site.)

Another excellent tool, supported and discussed in AVSForum is HDTVtoMPEG2. Note that it’s not really good anymore as a converter of transport streams (aka TS or .ts files) to MPEG2 but you can still use it to edit TS files.

See AVSForum for How to record via IEEE 1394 (Firewire) to Windows XP.

What’s the difference between PS and ES? Both are referenced in VideoLAN and the assumption is the reader knows what they are.

Well, here’s a simple description (since I’m just learning it myself): PS stands for Program Stream and contains both video and audio. ES is Elementary Stream wherein the video stream is separate from the audio stream. The video stream is normally an M2V or an MPV file and the audio is stored in MPA, M2A or AC3. Generally, neither PS nor ES files are readable by DVD players.

DVD players typically read VOBs which are very closely related to files in the PS format. The VIDEO_TS folder on a DVD will contain both VOBs and IFOs. No VOB can be larger than 1GB so the IFO tells the player how to combine the VOBs into the original program. If you want to join together all VOBs into a single file, you can somply concatenate them (Linux: cat *.VOB > one-big-vob.mpg, Windows: copy /b vob1.vob + vob2.vob + vob3.vob one-big-vob.mpg — thanks to Video Redo for a lot of this information, including the Windows copy command).

The federal government does some good work at time, despite the best efforts of our politicians! The Library of Congress has a wealth of information available over the web. In particular, the National Digital Information Infrastructure and Preservation Program (NDIIPP) has a catalog of various digital formats, categorized or alphabetical. It discusses AVI, for instance, its various subtypes (e.g. AVI_Cinepak and AVI_MJPEG) as well as what it may contain (e.g. WAVE and MP3_CPR).

Excellent resource for newbies like me!

This Afterdawn forum entry answers a lot of questions about DVD authoring (see the Wikipedia entry here.) Note that it does not cover transcoding, that is, the converting of one video or audio format into another. I’ll post an entry about codecs and such shortly.

Guess what I’m doing 🙂

Been looking for TV capture cards to add to my home-built PC and I thought I’d HD capability to it. Well, like just about everything that’s near the cutting edge, it’s WAAAYYYY more complicated than it seems. Here’s what I’ve learned:

Over-the-air (OTA) HD broadcast is known as ATSC and, if you want to receive OTA, you need a video capture device that can handle it. To keep things complicated, if you receive HD over a cable, you’re most likely receiving it in QAM (the Wikipedia entry for QAM isn’t too helpful as it discusses the imploementation, not what it implies for HD, so take a look at the entry for HDTV, instead).

OK, so, that covers OTA. Now, where I live, I don’t get too much OTA. I do have Comcast digital cable and they broadcast HD channels so I can mostly rely on their service. It turns out that they put their free (i.e. “local”) HD broadcasts in 256QAM so the capture device must be capable of decoding and decompressing 256QAM with ATSC optional. Well, most capture devices that are billed as digital or HD-compliant can do ATSC but not QAM. So far, I’ve found products from FusionHDTV, in particular, the FusionHDTV5 USB Gold, and the MyHD card.

Note, this doesn’t allow me to receive/decode encoded broadcasts like HBO, Showtime, ESPN, etc. For that, I’ll have to wait for a CableCARD-capable unit )supposedly I can get a card from Comcast in my area but, so far, there are no capture units that accept them).

Alternatives? Well, I’ve got a Motorola DCT6412 DVR (see this Wikipedia entry if you don’t know what a DVR is) that’s HD capable and has a Firewire port onto which it puts whatever channel’s being displayed on the TV. I’ve hooked it up to my PC and have been able to display appropriately-sized video windows (using information from this post to the AVS Forum) but haven’t been able to record anything so far.

So, what am I going to do? I’m not sure yet. I’ll post when I do. If you have any suggestions, please email them to me or post them as comments.