Sony TRV-38 MPEG EX Native Digital Video Format Question

I have a TRV38 and a ton of tapes that I have recorded with it. My
specifications claim that this unit records in MPEG EX format. As I look
through this group, the majority of advice when transferring from tape to pc
is to capture using DV-AVI format. Why wouldn't I want to leave the media
files in their native format as MPEG during capture?

RD...

I think I have figured out what the specifications are referring to with
MPEG Movie EX--seems to only have to do if you record to the memory stick.
Funny that the manual doesn't mention the native format for the Mini-DV tape
though.

webpa...

The native format of all Mini-DV tape is...(surprise!)... "Mini-DV"
provided only that it was recorded in a machine marked "mini-DV".

Jukka Aho...

The physical tape format is one thing, but the logical data stream on
the tape is used in several different tape formats - and in non-tape
formats too (computer files.) Besides MiniDV tapes, DV data (stored in
exactly the same format, with compatible codecs) also exists on 1)
full-sized DV tapes, 2) Digital8 tapes, and 3) DVCAM tapes. On
computers, a DV data stream can exist in a raw .dv data stream capture,
or inside an AVI or QuickTime wrapper (OMFI wrapper, too, if you want to
go into less common formats.)

Richard Crowley...

Which is all likely true, but does not negate the statement
that the format on mini-DV tapes is "DV". AFAIK, DV tapes
used for other purposes like data backup, still use the DV
format, but with data rather than video content.

Ken Maltby...

To the tape recording process "Digital Video" is "data". The
mechanism used to record the bits on the tape are the same
no mater what data is involved. The same on reading the tape.

Analog Video is a totally different matter, but in the digital
realm, at the tape level "data is data".

Of course, now we have a new tape format HDV using the
same physical tape cassettes. Not clear how different it is,
however. Maybe just the data content and not the meta-
organization, etc?

Ken Maltby...

The "meta-organization" is contained in, and described by, the
data itself, the tape doesn't care at all.

HDV = High bitrate MPEG2. On your tapes as a TS video

Frank...

720p HDV = 19.7 Mbps
1080i HDV = 25 Mbps

There are no variations on these rates, no artificial limiting by Sony
or anyone else. If PTravel read somewhere that Sony limited the 25
Mbps rate in one or more of its products, then all that I can say is
that whoever wrote that was misinformed.

PTravel...

It is possible that I read that only about Sony's ACVHD cameras, rather than
their HDV line. I'm a bit handicapped, because I can't websurf where I am
now, so I can't check. I know that Sony's HDR-UX1 is limited to 12
megabits, half of what the ACVHD spec can achieve. Camcorderinfo.com
reports the UX1 has a resolution in HD only slightly higher than what the
VX2000/VX2001/PD-150/170 can achieve in SD, though I always take Robin Liss'
reviews with a grain of salt.

If the bitrates you've cited are correct, and there is no artificial bitrate
limitation on Sony's HDV line, that certainly removes one of my big
objections to the HDV camcorders.

stream, most likely. (But the tape could care less.)

Frank...

720p HDV = TS (Transport Stream)
1080i HDV = PES (Packetized Elementary Stream)

Both are TS over IEEE 1394a, however.

One of many available references:

See chart on page 3 for basic characteristics of the HDV formats.

Luck;
Ken

Which fully defines the content of the tape in all ways, exactly the
same way the format of the content of a VHS cassette is fully defined
by the VHS logo on the machine that recorded it.

Jukka Aho...

Might be, but the VHS "logical format" (if you can call it such) only
exists on VHS tapes and nowhere else, which is different from MiniDV
tapes.

For example, it is possible to copy the DV data stream from Digital8
tapes to MiniDV tapes - or vice versa - with no loss of quality (other
than that caused by possible tape dropouts.)