[mythtv-users] Converting "mythtranscoded" files to avi...

[Steve Smith]

On 02/01/2008, Irumbo Mateene <imateene at hotmail.com> wrote:
>
>
> I installed and used nuvexport to transcode my nuv files to a format of my
> choice .. nuvexport supports several different formats  including ipod/divx
> and xvid formats..
>
> nuvexport is a stand alone script that can do the job for you ..
>
> You can also create a myth job that you can selectively run on the shows
> you want to convert to the format of your choice.
>
> for my needs nuvexport is more convenient as it allows me to interactively
> specify the bit rate and other things ..  you can start with nuvexport and
> once you know what parameters you use for encoding you can then create a
> myth job that will do the transcoding ..
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Folks,

I've been doing some experimenting:

What I'm Trying to Transcode to a Portable (i.e. non-NUV!) Format
================================================
Myth:0.20-fixes
Sources: 1) DVB-T (freeview) i.e. MPEG2-TS files
              2) PVR-150         i.e. MPEG2-PS files

Transcoded using Mythtranscode on MPEG4 settings to NUV files.

O/S Ubuntu Feisty.

What I've Tried So Far on the MPEG4 NUV files
==================================

ffmpeg:
----------
ffmpeg -i FILE.nuv -vcodec copy -acodec copy -r 25 OUT.avi
       Doesn't work at all. My version of ffmpeg doesn't seem to understand
the NUV container
correctly. It produces completely unplayable files.

NUVEXPORT  & nuvexport-xvid --mencoder:
--------------------------------------
      Bizarre!!!
      Coversion starts OK then at some point in the conversion all goes
haywire the left hand border of the picture moves to the centre and you get
wierd colour washes.
i.e.
       ||  The IT Crowd ||           becomes      | Crowd ||||  The IT |

This is the second time I've seen this effect with both DVB and PVR-150
original sources. Also with mytharchive trying to create DVD from these NUV
files.

vlc:
----
  VLC can play the nuv files on Windows with no problems, so I thought I'd
try its transcoding abilities. It seems that there are differences between
the Ubuntu and Windows versions.
Suffice to say the only one with any degree of success was:
 (Windows VLC)         NUV ---> MPEG2-PS
 This plays perfectly on VLC but on the DVD player it looks like the bit
rate is set way too low.

mencoder:
---------------
      mencoder INFILE.nuv -ovc copy -oac copy OUT.avi ( I forget the exact
syntax)

This produces ALMOST playable results. However glitches (maybe in the
original) means that the DVD player bombs out playing them. So a 1:30 sample
may only play for 5 secs before it "crashes".

THE BEST RESULT SO FAR IS:
      Using mencoder to Re-encode (yes I said I didn't want to do this!) to
XVID (in an AVI container).
      HOWEVER this results in the dreaded lip-sync problems, which the
yamada dvd-player doesn't provide adjustment for.







So:
   1) Has anyone else seen these nuvexport problems?
   2) Any other suggestions for NUV (mpeg4) to "portable format"?
   3) I'm considering replacing "mythtranscode" with something else e.g.
ffmpeg, mencoder -> divx etc. However in the past I've had lip sync problems
with MPEG-TS--> MPEG-PS any idea how to solve this?

It seems the "simple" matter of archiving my recordings to a portable format
is not really simple at all.


Cheers

Steve
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