Firewire IEEE 1394

Firewire is for wathing from Camcorders, not from HD optical devices.

Digital signals must have HDCP, firewire doesnt have that. Plus firewire is in the first place for compressed signals. Not decompressed signals.

I should add the above comments apply to video firewire, Not audio firewire. The input on your HDTV will be for video only though.

Firewire will pass both audio and video, so the input on his TV will work for audio as well!

I always describe TS streaming firewire as Video and A&M Protocol SACD/DVD-A firewire as Audio. I might be wrong but it makes sense to most people.

There would be little to no advantage using the firewire TS interface for audio (Worse than Coaxial) or video since the stream from Blu/HDDVD must be protected and MPEG2 ones are too higher rate whilst AVC/VC1 are generally unsupported by TS firewire anyway. For a Blu or HDDVD recorder TS firwire input for recording is useful. In fact the Sharp Blu recorder and Toshiba Japanese HDDVD recorder have a Firewire TS input.

Audio firewire is a diffferent matter. It is copy protected, it is AACS approved (So on par with HDCP) and does carry full res uncompressed PCM and DSD. It has advantages and a use in Blu/HDDVD players.

MovieSwede commented:
> Digital signals must have HDCP, firewire doesnt have that. Plus firewire is in the first place for compressed signals. Not decompressed signals. <<br />
Completely bogus. Have you ever heard of DTCP (aka, 5c)? Just because FW is suited for compressed signals does not mean that the sets themselves can't decompress and display the HD signals... which, in fact, they can. Take a compressed, protected digital signal from a cable co. STBs firewire output, and feed it to an appropriate TV with FW input. After negotiating the security handshake, the TV will decode, decompress, and display the video stream.

Krobar added:
> The input on your HDTV will be for video only though. <<br />
Also bogus. The FW stream carries BOTH video and audio signals.

> There would be little to no advantage using the firewire TS interface for audio or video since the stream from Blu/HDDVD must be protected <<br />
No problem there.

> ...and MPEG2 ones are too higher rate <<br />
This is also incorrect. No MPEG2 streams from HD optical media come anywhere near the 400 MBit/sec capacity of FW.

> whilst AVC/VC1 are generally unsupported by TS firewire anyway. <<br />
Not unsupported by FW itself (it could carry it), but certainly any receiving device would need to know what to do with it, and no TVs that I'm aware of do (or ever will, with the waning of FW, partly based on widespread misconceptions, as echoed here).

And to the OP, Vitale asked:
> I have had these useless Firewire ports on every HDTV I've had since early 2000 and not one high end electronic that I've owend ever had an output for this elusive creature...... <<br />
They're not useless if you have a cable STB, or a digital camcorder, or a D-VHS tape deck, or an Indigita AVHD Hard Disc Drive, or a Moxi HD DVR with FW, or a PC with FW to record OTA tuner material and play it back.

You ARE correct that none of the sat.cos. support FW output, which has negatively impacted its value/usefulness. And none of the consumer optical disc players support it either.

> If they are not going to make anything to use them on, remove them from the TV sets and charge me less! <<br />
That is exactly what is happening. Well, at least the "removing" part.

- Tim

Firewire may have a capacity of 400MBit/sec but the receiving devices CANNOT process a 400Mbit MPEG2 stream. Most HD Mpeg 2 TS inputs are limited to around 25-40Mbps and depending where the device is in that range limit it would leave them incapable of decoding a full rate Bluray MPEG2 stream.

Thanks, Krobar.

That's interesting. I wasn't aware Bluray MPEG-2 streams went that high. But the point is moot in that most optical HD content will be one of the MPEG4 variants, which few devices would be able to recognize or process (perhaps a future media player device?).

- Tim

1394b firewire cables can achieve way higher data rates of both audio and video.

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