Using deinterlace filter vs. video quality

Started by MetalMania, August 04, 2015, 12:13:22 PM

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MetalMania

Hello

I'v about 200 gigs of DVB-T material that needs to be reencoded. All files are interlaced. My question is this. Is it relevant or not that deinterlace filter is used in avidemux in terms
of video quality (does bit rate rise?) of recoded material? At what stage such filters are being applied? Does encoder even "know" about that or not? If it doesn't "know" i guess it doesn't matter?

Regards

AQUAR

#1
It depends very much on the type of source material, type of playback display, capability of the media player, what kind of deinterlacing method used etc.

EG, if it was a movie (=progressive source material), then the DVB PAL would be interlaced as segmented progressive material.
Avidemux, setup without any interlacing filters in the filter chain, weaves the fields back together.
And in this case you would get a recode with proper progressive frames.

If the DVB material was true interlaced material.
Avidemux, setup without any interlacing filters in the filter chain, weaves the fields back together.
And in this case you would get interlacing artifacts on a progressive display (ie quite useless!).
So, instead you need deinterlacing somewhere in the recoding chain (avidemux filter) or post processing chain (media player, digital TV!).
I would do it with an avidemux filter, and give it time and bit rate for good quality recode (but it really depends on your setup!).

There are many other scenarios like this and you just need to discover what applies best.

MetalMania

Thanks for answer, but I know all of that.  It's mostly sports so i suspect its "true" interlaced material. I'll try to put the question anther wayy. How does encoding stream look in avidemux?

Input data -> filter -> encoder -> output data
or
Input data -> encoder -> filter -> output data



AQUAR

#3
You know all that!
Except what amounts to the logical workflow needed, for a recoded product in a container, to suit the intended playback method.

Option 2 says - recode the source first, apply a filter and then mux that result into a container?
Think about why that can't work as part of a video editor's work flow.

You can of course do a recode with ADM to create a new media file, and then apply filters on the decoded media file elsewhere (to do say de-interlacing).

Basically ADM does: demux the source to separate its streams - decode these streams - filter the raw data streams (if filters are added) - recode the raw data streams  - mux the streams into a container.

So set ADM up to meet whatever you desire to meet your playback requirements.