DVB files - interlace changes midway through file

[lordsmurf]

How do people work with DVB files?

I have some 480x480 files that come from DVB streams (digital satellite). The interlace field dominance changes from bottom field (BFF) to top field (TFF) in the middle of the video. Because of this, it is impossible to re-encode to a DVD-compliant file, at least with any method I have tried. You end up with a file that plays fine, but starts to "go jerky" on you about halfway through because the wrong field is now first.

There is also a slight audio/video sync delay if you try to re-encode the files.

How do people work with these? What do you do?

What software besides DVD-Lab can work with DVB files? What are the options for authoring as-is?

Or does somebody know the way to fix these files to where a single field dominates the whole length of the video?

[The_Doman]

How do people work with DVB files?
How do people work with these? What do you do?

What software besides DVD-Lab can work with DVB files? What are the options for authoring as-is?

Maybe you can try it with TMPG DVD Author?
(Possible after demuxing with Project X?)
The only real problem are the non DVD compliant DVB resolutions, which TMPG DVD author will NOT accept.
I always use this trick with DVDPATCHER to let TMPG DVD Author accept those files:

- Patch the MPEG recordings with DVDPatcher to a valid DVD resolution (720x480 for example)
- Open the file in TMPG DVD Author, but don't do anything yet! (the picture can look distorted)
- Now immediately patch the MPEG file back with the original size values.
- Continue Authoring with TMPG DVD author, everything should work fine.

Ofcourse not all DVD players will playback the created DVD correctly....

[lordsmurf]

TDA says "could not initialize decoder"

edit: Must patch WHOLE FILE and not just header..... so far, so good.

[lordsmurf]

I give up.

I burned the file to SVCD (small enough) and will re-capture it on a DVD recorder (DVD player plays SVCD).

[ronnylov]

All my DVB files are with top field first. Have never seen it change. But I have seen the aspect ratio flag change, for instance at commercial breaks or at start and end of program. Processing the DVB file in PVAStrumento will split the file at format changes (like changed aspect ratio or changed audio). Perhaps it also will split at changed field order?

Sometimes I use ProjectX to process the file but this program won't split the file at format changes (not at default settings at least). So I manually fix the aspect ratio flag with ReStream. You can also change the field order flag with restream but it might not help because you don't actually chage the real field order when changing the flag. It can be worth a try at least to see what happens if you change it with restream.

An alternative to burn it to SVCD may be reencoding it to DVD format with software. You can use an avisynth script to fix the field order, or alternatively encode the different parts to separate files and link them in the DVD authoring process.

[SatStorm]

I filter and re-encode my DVB captures since 1999. (technically this is not a capture, it is a DATA transfer from satellite to PC). There is no other way. The only exception are the few channels that transmits on 352, 704 or 720 x 576 (480) framesize or to use DVD Lab to make an xDVD

The fild order thing is very rare in Europe. We mostly have to deal with interlace / non interlace switches that doesn't harm so much the picture

I suggest to load your DVB files to virtualdub mpeg2, use couple of filters, frameserve and encode.
Most DVB channels need heavy filtering before you can convert them to anything usefull.

Your best friend we have with the compression artifacts, is virtualdub's msu_deblocking (or smart de-blocking) filter.

[TBoneit]

Did you try VideoReDo I Use to fix DVB files from DishNetwork DVRs

[lordsmurf]

I think I pretty much tried every solution you guys suggested, to no avail. VirtualDub, AVISynth, Restream, VideReDo, PVAStrumento , ProjextX ..... most of them just butchered the file more.

[SatStorm]

Then something else happened.....

Try the classic approach (if that doesn't work, nothing will...)
DVD2AVI => TMPGEnc

[SatStorm]

Then something else happened.....

Try the classic approach (if that doesn't work, nothing will...)
DVD2AVI => TMPGEnc

[lordsmurf]

DVD2AVI fails too. Tried that. The files are just wacky.
SVCD to DVD recorder works though. Still looks good.

[TBoneit]

When you tried VideoReDo did you run the QuickstreamFix off of the Tools menu? I know it was modified at some point in the past to fix DVB from Dishnetwork that would cause sync problems due to changing pulldown and such midstream in the recording. For me many Dish files needed QSF before they could even be worked with. I ended up extracting to .ts and then QSf'ing to Mpeg file and edit from there. I'm thinking you either have Dish or DirecTv? being in the USA.

[vhelp]

LS, it's a little bit more work than you may want to do, but..

If you consider your source "valuable" to some degree, then there are several
method I can suggest, below and using vdub or avisynth, but which would require
a re-encode.

Note 1, there are several ways of referencing this source condition:
** BFF or TFF
** Fields Polarity order
** Field Inversion, etc.

1 - first examine whole video source for *each* BFF/TFF break or swap, and note frames
Begin and End points. This is necessary to tally all the swaping

2a - if using an AVIsynth script, write a function to swap from *that* frame, it's
frame's BFF or TFF (polarity) order, according to each of your recorded bff/tff frames,
and again, noting Begin and End points, and process your AVI source file(s) this way.

( using AVIsynth might be the better/quickest way. The time consuming part is the
video examination part for bff/tff polarity changes. And, it don't have to be for
any specific IVTC at all, rather, to purge (clean) the source of this garbage. )

After determining that your source is a mixture of bff and tff polarity..
Say you want to make your original source all BFF, you would hunt down and process
only those sources that are TFF, and change them all, to BFF. Its that simple.
But, writing the script may not be, for some.

But, you could start out with something like this:

 FunctionBFForTFF( frameBegin, frameEnd, bff) or,
 FunctionBFForTFF( frameBegin, frameEnd, tff)

I'm sure someone here would be nice enough to quickly code something up for you
here, 123

See AVIsynth functions:
** assumeBFF()
** assumeTFF()

2b - or, if using vdub, (after determining *every* BFF/TFF break/swap) setup vdub
to "save out" to another AVI source file, each bff/tff sequence, to correct AVI file,
using this method:

a) open vdub, and import your AVI source file, then
b1) video\frame rate\(o) Reconstruct from fields - manual: offset: [3 ]
b2) video\frame rate\(o) Reconstruct from fields - manual: [x] invert polarity
( when the polirity changes, uncheck it this box, ie.. [ ] invert polarity, for
each Save as, to AVI file )
c) choose a Compression that best fits your video quality processing requirements.
d) Save as, to this AVI file(s) with File\Save as AVI\your filename.avi
e) merge all the processed AVI files.

In the end, we should have nothing but clean BFF or TFF files, depending on what
your target goal was.

Note 2, when using vdub route, this is assuming that your source is Telecined,
and you want to bring it back to 24p for further benefit/processing. Same goes
for AVIsynth too. Though, with avisynth, your source would be more cleaner with
a proper bff/tff filter throughout, without actually aiming for an IVCT. IOW, it
don't need to be a Telecined source if using avisynth to do this proces. But, I
would like to point out, that whole purpose of this filter process is for IVTC
projects.
But, what if you've determined that your source is non-IVTC'able ? see otherwise.

possible TIP:

If your source has a logo already embeded in it somewhere (usually at bottom right)
then, use it to your advantage, (if you can, as it don't always work) and watch
for it BOBing up/down during your pre-video examination for BFF/TFF polarity.

I did say it was more work

fwiw nothing here.. for some reason, no one ever thought of writing a virtualDUB
filter for a polarity check on/off filter. And I don't think anyone will ever do
one neither. But, as I noted above, the better method is probably through AVIsynth.

Otherwise, the easiest way of dealing with such sources, is don't. Just encode
as 29.970 fps and use a higher bitrate than normal.

-vhelp 3941