Otto J. Makela wrote:
I just got confirmation from our friends at Metakine that their M2VRequantiser
also produces garbage on my original test data, so the conclusion is that the
equivalent of:
tcdemux -i videofile-dvd.mpg -x mpeg2 > sample.m2v
will produce video content to sample.m2v which (though it will play with
programs like xine) cannot be handled by tcrequant or mplex.
What is your suggestion, what can be done to fix this?
In view of this question about tcdemux it might be useful for me to
clarify both my experience of successfully using tcrequant in the past
and what I meant by .vob files when describing my experiments with vamps.
I have been using MythArchive to create dvds from dvb-t recordings. All
recordings have been stripped, in mencoder, of all except one audio
channel before lossless mpeg2 transcoding with a cutlist by
mythtranscode. Output is (probably) mpeg2 PS.
MythArchive then uses
mythreplex --demux --fix_sync -o outfiles_prefix -v 224 -a 192 "infile"
the code for which is replex.c within the mythtranscode package; I don't
know what its history is or how it may be related to tcdemux. tcrequant
is called if needed to shrink the video file before mplex -M -f 8 and
dvdauthor.
I saw artefacts here in fc10, none in CentOS. Target shrinkage was
rarely more than a few percent.
The experiments I have done with vamps in fc10 have used the output of
the mplex -M -f 8 stage with target shrinkage up to 2.0 - and no prior
passage through tcrequant. I haven't seen artefacts although obviously
the quality is reduced. These files are what I referred to as .vob
files. vamps may report an error on reaching EOF, and the MythArchive
code sometimes reports fatal buffer underflow in mplex, and exits, after
creating an output file although I don't think it reacts similarly when
using a FIFO. I think I can avoid this by mplex -M -f 8 -b 500 -r
15000 but have only tried this once.
Code for use in the real world ought to be robust, but are there
definitive examples of standard-compliant input for testing tcdemux?
HTH,
John P
