SDTV PAL 576i -> end result encoding to xvid

[Mshake]

Hi all,
Been spending some time experimenting and reading. Joined the forums long ago still haven't managed to read EVERYTHING....

I have mpeg2 files captured from SDTV sources (720x576i@25fps). I believe these PAL broadcasts are interlaced sources and I can encode them nicely using all the available de-interlacing methods out there (using G-knot and modifying the avisynth scripts).

my query is:

1) Interlace sources contain artifacts/black lines if viewed through a computer monitor or using newer CRT that displays progressive images. So de-interlacing mpeg2 files using all these filters is merely a way to make the video file as progressive as possible? I am taking the word 'progressive' as meaning displaying each frame progressively and each frame consists of 1 field and not 2 interlaced fields?...

Apologies for the simple question but any absolute answer to this will help me understand this entire thing better.

[unskinnyboy]

Yes. Apart from the fact that de-interlaced video looks better on a progressive display device, it also allows for better compressibility when encoding the material.

To know more, just use search. You will get plenty of threads to read. These are these basics of video compression.

[SeeMoreDigital]

Also... although XviD's "encoder" filter offers the ability to generate interlaced encodes, their "decoder" filter does not offer the ability to play and display such encodes correctly in a software based player (mind you, neither does any body else's decoder filter for that matter) - which I think is a great shame :(

By contrast, most stand-alone (hardware based) players do offer the ability though - as far as I know.....


Cheers

[unskinnyboy]

Also... although XviD's "encoder" filter offers the ability to generate interlaced encodes, their "decoder" filter does not offer the ability to play and display such encodes correctly in a software based player (mind you, neither does any body else's decoder filter for that matter) - which I think is a great shame :(
SMD, what exactly do you mean by decoders do not offer the ability to play and display such encodes correctly? You mean interlaced video cannot be played back properly as interlaced? I am a bit confused here.

[SeeMoreDigital]

Indeed...

I've generated quite a few interlaced MPEG-4 streams using XviD's encoder (from pure interlaced MPEG-2 sources) and am yet to find a direct-show based decoder capable of playing/displaying them properly!

In my hardware devices they play/display fine ;)

[unskinnyboy]

Well, that is interesting, because I don't think I have ever faced any issues viewing interlaced content. But these interlaced content were not the kind you mentioned (namely, interlaced XviD from interlaced MPEG-2), but rather, either interlaced DVDs or badly telecined content with lot of combing etc. But since interlacing looks annoying on my LCD monitor, I usually deinterlace it via ffdshow or use one of the built-in deinterlacers in VLC Player.

Can you cut me a sample of the material which you had issues with (if you still have them lying around)? I am curious to see it for myself - because I am not sure what problems you experienced.

[SeeMoreDigital]

Yea....

Most, if not all MPEG-2 direct-show decoder filters can play/display pure interlaced MPEG-2 content just fine!

Anyway, here's a high-def (1920x1080/88) pure interlaced MPEG-2 source (http://www.one.seemoredigital.net/Temp_Files/Pure_Interlaced_HDTV_MPEG-2_Source.zip) and here's a pure interlaced MPEG-4 encode (http://www.one.seemoredigital.net/Temp_Files/Pure_Interlaced_HDTV_MPEG-4_Encode.7z).


I guess I could supply some std-def samples at some time as well

[unskinnyboy]

If you meant the interlacing is showing up more as an ugly aliasing, yes, I am getting it - ffdshow, VLC & MPC. In MPC, the deinterlacing option for MPEG is set to auto, but this doesn't kick in when playing back MPEG-4 (maybe it isn't meant to be), it does automatically deinterlace the MPEG-2 source though.

[Mshake]

unskinnyboy,

Thanks for the clarification and answering my question.

Yea the search button has been my good friend although at times, it led me to confusing websites and threads. It is actually rather hard to read through all threads and pin point who is the knowledgeable person speaking the fact and who are the 'not-so-knowledgeable' ones....no offence to anyone intended.

once again, thanks...now eveerything's clear. I understand.

My main display box is using a sony widescreen crt currently set at 720p. Maybe that is why I am seeing those black lines when viewing mpeg2 file. I am guessing my HDTV tuner hooked up to the CRT auto-deinterlace through hardware when displaying live broadcast.

Testing through a few de-interlace filters but so far to the naked eye, it's very hard to pinpoint what the differences are between those avisynth filters (i am sure there are!).

The mpeg2 file i am testing/encoding are all the worldcup matches so i am looking for sharp/unblurry kinda filters...thanks. (not asking for any filters i think i know where to look and find em).

[SeeMoreDigital]

If you meant the interlacing is showing up more as an ugly aliasing, yes, I am getting it - ffdshow, VLC & MPC. In MPC, the deinterlacing option for MPEG is set to auto, but this doesn't kick in when playing back MPEG-4 (maybe it isn't meant to be), it does automatically deinterlace the MPEG-2 source though.Shame isn't it....

Hopefully when the guys at Core develop their CoreASP decoder they'll release it/a version with interlaced support... like they have done with CoreAVC ;)

[Mshake]

SeemoreDigital....

love your "Life Looks better in HDTV" heh