Tuesday 14th of February 2012 03:11:33 EST
   Lost S06E08 720p HDTV X264-DIMENSION

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[#130289] Written by: Totz [17/03/10, 11:51]
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Audio is terrible on this.. not out of sync, just way too bassy.. it overpowers the ambient sounds
and it's hard to distinguish voices

and the video isn't great either, far more blurry than usual
[#130290] Written by: sinin [17/03/10, 13:26]
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I have always seen issues with pretty much ALL the Lost MKV files. For some reason it looks as
thought the pulldown on the encoding isn't working properly. You will see the image stutter, which
is especially noticeable on panning shots.

I'm not sure if this is something to do with the broadcast, the encoding process or the person doing
the encoding. I know this will be ripped from broadcasts in the US, but other broadcast from the US
(such as 24) are perfect. Again this maybe that 24 is broadcast on Fox HD, whilst lost is on ABC HD.

Anyone have any clues on this, I would be grateful to understand why this happening and can it be
overcome?
[#130296] Written by: kain [17/03/10, 13:58]
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This one's ripped from CTV (Canada, isn't it?).

Video quality pretty much sucks... too much contrast, blended colours and much compression-artifacts
[#130309] Written by: eetaylog [17/03/10, 16:31]
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+1, the video quality of this file is not much better than an SD .avi file. Hopefully next weeks
will be back to normal.

As for the above comment regarding stuttering, its because the broadcast is at 23.9fps compared to
the normal 25fps. Not sure why ABC have done this?
[#130314] Written by: sinin [17/03/10, 17:49]
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Actually, the NTSC HD broadcast with be 1080i/60Hz, or possibly 720p/60Hz. The frame rate is
actually set at 29.97 fps. To achieve this for a film originally shot at 24fps, they use a process
called 3:2 pulldown (also known as telecine). There is also a slight slow down in the original
footage that make is 23.976fps.

However, when the rip is made the encoding process should reverse this 3:2 pulldown and so get back
to the original 24fps (well actually 23.976fps).

It doesn't actually matter that I'm in a PAL country watching my TV at 50Hz (25fps). My PC has a
refresh rate of 60Hz as standard for most LCD, and if I feed my flat panel using VGA, the PC will
essentially sees the TV as a monitor and sets the refresh at 60Hz. BTW, my TV supports both PAL and
NTSC formats + 24fps. Still, there is judder evident on every Lost MKV i have seen.

I believe that this is down the the encoding process, and either the person or the program encoding
the rip not applying the reverse telecine correctly. If you actually move frame by frame through an
episode of Lost during a pan you will see the frame jump.

This CAN be done correctly - just look at the MKVs of 24.
[#130317] Written by: sinin [17/03/10, 18:02]
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Of course, if Fox broadcast in 720p and ABC in 1080i, this might also be the root of the problem.

It is relatively simple to reconstruct the original frames from a progressive broadcast - as all the
frames as broadcast in their entirety for each field.

However, in 1080i, the frame is interlaced, so 2 out of 5 fields are actually a composite of the two
frames. Reversing this can be tricky, but can be done I believe.

It all get a bit complicated,
[#130323] Written by: omglearntogoogle [17/03/10, 19:37]
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It's related to the ABC broadcast. ABC broadcasts at 60fps but also employs a method of removing
certain frames to compress an episode down runtime wise to fit in more commercials. Watching it on
TV it is fine because you are seeing the standard 60fps broadcast but any rip has to be downsampled
to 23fps, the problem is their is no pattern as to which frames ABC removes and therefore certain
sections becoming jerky and have combed or blended frames.

They started doing this a couple years back and have kept on doing it, basically if you compare the
runtime for the XVID (sourced from CTV) to the 720, you'll notice the 720 is shorter but with no
missing footage. Just the same footage with certain frames compressed to speed up the broadcast.
Some groups started propering for this but the practice fell off when Canadian sources fell apart.
Also not helping is the general lack of upload speed for Canadians making the episodes take longer
to upload and therefore other US groups beating them. It sucks but its ABCs fault and greed for
wanting to sell 1-3 more spots per hour of programming.

Sometimes Lost airs a couple hours earlier in Canada and the XviD is sourced from that broadcast,
sadly its hard to upload 1.1gb with Canadian upload speed. So the 720 (which is where the real
quality should be) is still sourced from the inferior abc frameraped source
[#130352] Written by: eetaylog [18/03/10, 05:11]
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Good explanations lads, well worth reading ^^^
[#130373] Written by: sinin [18/03/10, 13:16]
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Interesting. Thanks for the update.
[#130675] Written by: sinin [23/03/10, 04:15]
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FWI, after viewing this episode I actually thought that the sound and colours were fine when viewed
on my 42" plasma. This is by far been the most stable rip of the season so far - lovely motion and
not a hint of telecine judder.
ipv6 ready