Re: Am I wise to convert all my AVIs?

Andy <nomail@xxxxxxxxxx> writes:
For the extra 14% i would say it is worth having the movie as an
MPEG rather than an AVI. Would playback quality of the MPEG-1 be
less than the AVI?

On 22 Apr 2006, Phil Carmody<thefatphil_demunged@xxxxxxxxxxx> wrote:
Was the playback quality less than the AVI?
If it was, then yes.
If it wasn't noticably worse, then it's not noticably worse.

There's _no way_ it can ever be better quality, as moving
between lossy formats almost always doubles your lossage.


Phil

I had *assumed* that the extraction process performed by my Blaze Media
Pro would remove the AVI wrapper and therefore I thought that the
quality of the un-wrappered "underlying MPEG" (which I would receive as
a file from the extraction process) would not be of a different quality
than the MPEG inside the AVI.

If you have some information to support that assumption, then it
may well be a fair one. If you have no such evidence, then it may
well be false. Last time I converted a windows-esque format to
MPEG, the program I used _definitely_ went via a reconstruction
of the video stream. Note that an AVI may contain any number of
different video-compression formats as its payload, more than
there are variations of MPEG. You might be lucky.

If I have understood you correctly, it seems that I have made some
incorrect assumptions because you refer to extra losses.

I would make a guess that the additional losses you refer to come from
the extractor utility effectively 'playing' the AVI and then re-encoding
that played output into a new MPEG. Presumably the extra losses come
from the compression of the video images into that new MPEG.

Is my understanding now correct or am I getting hopelessly tangled?

You might be perfectly correct. Use an AVI player to tell you about
the compression format used inside it. If it's claiming to be carrying
MPEG, and it's not some unpleasant bastardisation thereof, then you
might be lucky, it's entirely possible.

Phil
--
What is it: is man only a blunder of God, or God only a blunder of man?
-- Friedrich Nietzsche (1844-1900), The Twilight of the Gods
.