[mythtv-users] Capture to DV or "uncompressed" AVI instead of MPEG-PS?

[Gregg Casillo]

On Tuesday 05 April 2005 05:43 pm, Joseph A. Caputo wrote:
> On Tuesday 05 April 2005 17:25, Allan Stirling wrote:
> > Gregg Casillo wrote:
> > > I doubt this is possible in MythTV, but if anyone knows if/how it
>
> might be
>
> > > possible to capture to DV or some sort of uncompressed AVI, please
>
> let me
>
> > > know.
> >
> > Riiight.
> >
> > DV is MPEG2.
>
> Um... no, DV is not MPEG.  What you might be confusing is the fact that
> Myth now supports capturing MPEG-2 data over Firewire from digital
> set-top boxes.  Since Firewire is the common transport for digital
> video cameras, it would be natural to assume that they also use an MPEG
> codec, but the fact is that they use DV, which is an entirely separate
> codec (with much less compression than MPEG, AFAIK).
>
> However, now that Myth supports a Firewire interface, it should be
> possible to write a video capture class that can capture DV.  It's been
> mention before on either this or the -dev list as being a possibility,
> but I don't know if anyone's actually working on it.
>
> -JAC
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This is my understanding about DV too. I had a Sony PD150 for a while and 
transferred from its Mini-DV tapes to my PC via Firewire cable. The 
"uncompressed" AVI files (I use quotes advisedly because they are actually 
compressed lightly) I got were in the ballpark of 13GB/hr. I believe this is 
right for DV files with video & audio included.

At both home and work, editing of captured files and archival to DVD are 
crucial. I know how to go from MPEG2 to MPEG4 which is simple enough, but I 
rarely do this. However, I'm in the position of having to go from MPEG2 to 
MPEG2 (without commercials and *with* DVD NAV packets for authoring and 
burning), and this is proving difficult.

It is my understanding that going from a MPEG4 source file to MPEG2 will 
result in loss of quality. Unless I use a super-high bitrate in my MPEG4 
file, no?

Gregg