HD to 'standard'?

[Wolfmancatsup]

Hi all - had a quick search on the tools area, but couldn't find the info I needed (well, it wasn't too obvious anyhow) - I'll need to be able to convert some high-def dvd's to 'normal' resolution in a few weeks - is there a tool that does it or is it not that easy? I've done stacks of DVD9 - DVD5's, so I'm not a complete novice, but I've never even seen a high-def dvd... These will be PAL.

Thanks for any help given (no flaming, please!)

Mick.

[BJ_M]

high def - but from type of codec ?

do they have DRM ?

[Wolfmancatsup]

Unfortunately I have no way of knowing this until I get my hands on them in a week or two. They're from the BBC, and they're the full ten hours of Live 8 from Hyde Park here in London, but that's all I know about them.

Mick.

[dphirschler]

At least we know the HD video standard for these.

http://www.digitalspy.co.uk/article/ds22165.html

1080 lines and 50 interlaced frames a second, with a display screen of 1920x1080 pixels

Do you plan to keep it PAL?

You should be able to do a bob, then resize, then weave in AviSynth. How well do you know AviSynth? Remember to calculate the anamorphic size when you are resizing.


Darryl

[dphirschler]

Here's my quick script for converting 1080i HD to SD. Note, this is NTSC. You will have to change it for PAL. Without testing, I would guess that simply changing 480 to 576 would do it.

# Converts 1920x1080i to 720x480i anamorphic
function v720x480i(clip v)
{
	# deinterlace the video
	v=bob(v)

	# resize the video
	v=v.BilinearResize(720,480)

	# re-interlace the video
	#v=v.SeparateFields.SelectEvery(4,0,3)#BFF
	v=v.SeparateFields.SelectEvery(4,1,2)#TFF
	v=converttoyuy2(v)
	v=weave(v)

	return(v)
}

Darryl

[edited to add comments to Avisynth script]

[edDV]

At least we know the HD video standard for these.

http://www.digitalspy.co.uk/article/ds22165.html

1080 lines and 50 interlaced frames a second, with a display screen of 1920x1080 pixels

Do you plan to keep it PAL?

You should be able to do a bob, then resize, then weave in AviSynth. How well do you know AviSynth? Remember to calculate the anamorphic size when you are resizing.

Darryl

From BBC it will most likely be 1080i 50 fields per second in some form.

For computer display or if the source is film, a simple drop of every other field gets you a progressive frame but the cost is half the motion resolution (25 vs 50 fields per second) if the original was shot with an interlace HDTV camera. Another name for single field conversion from 1080i is 540P since half the lines are tossed and progressive 25 frames/s stream results.

If the source was a HDTV camera running 1080i at 50 fields per second then Darryl's method (bob+weave) or another more sophisticated deinterlacing algorithm to 576p or a simple x and y downscale to 576i are the alternatives.

If the TV is interlace, I for one find 576i to DVD simple, direct and results in minimal artifacts plus full motion resolution.

If the TV is a progressive EDTV or HDTV (e.g. LCD, plasma, etc.) then you should evaluate the HDTV set's internal deinterlacer (with 576i input) against the software deinterlace and choose what looks best on your set.

576i will save you many hours of CPU time.

[Wolfmancatsup]

Thanks guys; loads to read (and try) there. I've not used AVISynth all that much, and I think I was following guides on here step-by-step when I did, so I didn't take too much notice of how it worked. They will stay in PAL as well, as I live in the UK (and was at Hyde Park too, and wanted a nice reminder of the day!).

Many thanks guys.

Mick.

[dphirschler]

Try this to convert it to NTSC 29.97i. This method works pretty well with PAL SD video but can produce a shimmering effect with horizontal lines. That effect should be absent from this conversion from HDTV because of the higher resolution.

# Converts PAL 1920x1080i to NTSC 720x480i anamorphic
function vPALtoNTSC720x480i(clip v)
{
	#input TFF or BFF
	v=assumeTFF(v)
	#v=assumeBFF(v)

	# deinterlace
	v=bob(v)

	# resize and reinterlace
	v=v.BilinearResize(720,480)#DVD resoution (anamorphic)
	#v=v.ChangeFPS(59.94)#crisp but slightly jerky
	v=v.ConvertFPS(59.94)#smoother but slightly blurry

	#v=v.SeparateFields.SelectEvery(4,0,3)#BFF (even)
	v=v.SeparateFields.SelectEvery(4,1,2)#TFF (odd)
	#v=converttoyuy2(v)
	v=weave(v)

	return(v)
}

Darryl