|
fps
|
Method |
%
|
Important Details
|
(1) |
50 fps
720x288 |
Field Bob
(Method 4a) |
100.0%
|
Virtualdub's "Sharpen" filter
set to 10 to compensate blurring of the "Field bob"
filter. |
Compared to an uncompressed movie this is about 1:106. It's fascinating to see what DivX is capable to do without nearly any visible loss.
This could be the deal for you. However for best results use method 15.
|
(2) |
50 fps
720x288 |
Field Bob
(Method 4a) |
97.1%
|
The same as (1)
but keyframe interval
is set to "500". |
3% saved without sacrificing quality is not bad. The drawback: Seeking (fast forwarding/
rewinding) takes longer. |
(3) |
25 fps
720x576 |
Blend |
86.7%
|
|
Don't do it. Result looks bad. You lose details and motions are unnatural.
This method is called "(best)" in Virtualdub while in my opinion
it's not, but it's a matter of taste (Please see the 2 swing sample pics
below).
Even "25 fps, resize to 384x288" (8)
is better. |
(4) |
25 fps
720x288 |
Discard field 1 |
74.2%
|
|
You definitely lose the half info, movie is unfluid, but result is sharp
and saves you about 25%. Only 25%, I might add, because you give up 50% of
resolution and 50% of fluidity. |
(5) |
25 fps
720x288 |
Discard field 2 |
75.2%
|
|
Interesting: In this movie all odd fields were harder to compress than even
fields. |
(6) |
25 fps
720x288 |
Field Bob
(Method 4a) |
61.6%
|
Sharpen+Drop every second frame. |
This is astonishing: Drop every second progressive frame should be
theoretically the same as "Discard field2". But since I use
filters like "Field Bob", that blurs a bit, it's not. |
(7) |
50 fps
384x288 |
Field Bob
(Method 4a) |
60.9%
|
Sharpen+Resize down (decreased width
until it matched 4:3). |
In my view this is the method of choice, if size matters a bit, but not too much. You get a superfluid movie and the loss of visible information is not too high and you keep your movie 4:3.
This could be the deal for you if size matters a bit.
|
(8) |
25 fps
384x288 |
Resize down to 384x288 |
36.7%
|
|
You size down to about 27% of the original film BUT the movie is kind of
strangly unfluid/blurred. For 27% of the original quality you get 37% size.
In Virtualdub the deinterlace filter "Blend" is the same as
"Resize down" except for the resizing. So you get exactly the same
result, except the Blend'ed picture stays the same size and the downsized
one is a little more blurred of course,
because of the smaller image size.
This could be considered a typical looking movie downloaded from the
internet. A bit unsharp and not fluid, but small.
|
(9) |
25 fps
320x240 |
Discard field 1 |
29.6%
|
Resized down to 320x240 after
discarding every second line. |
In my view, it's a matter of taste whether you like resizing down (8) or discarding+resizing down
(9). (8) gives you a
blurred picture, (9) gives you a unfluid but sharp
movie. Because it's quite sharp you can resize it down more. (How
can a lower resolution be better?)
But I could agree that (3) and (8)
can give you a good quality if the footage has a lot of static areas (like
news broadcasting).
Once you get
used to its unfluid play you will appreciate the sharper image quality.
I
would say this is for sure the method of choice if you have an NTSC movie, because
the frame rate of NTSC (ca. 30fps) makes the movie more fluent anyway.
And when I say
unfluent for PAL systems (25fps), then this still far better compared to typical internet clips with
15 fps or 12 fps. Shame on you, you internet uploaders.
The difference between (8) and (9)
stays clearly visible even if you resize to small frame sizes, even below 384x288:
Method (9) (Discard)
Method (8) or (3) (Blend or resize down).
You could call these effects "Ghosts".
This deinterlacing method a very good and fast solution:
1) |
You work within Virtualdub only, thus very fast, no Avisynth needed. |
2) |
Discarding is fast. |
3) |
Resizing is fast, because you resize only the half info after
discarding. |
4) |
Compressing is fast because you compress a lower height/width. |
5) |
Height/width ratio is correct |
6) |
Since most of you will resize the final footage down
anyway, discarding a field (=losing half of the resolution) isn't
that bad. |
7) |
Leaves you with absolutely no interlacing artefacts. |
This could be the "good speed/quality/size ratio" deal for you.
|
(10) |
25 fps
720x576 |
Duplicate Field 2 |
137.5%
|
|
This is the same as "Insert Field2 instead of Field1" thus
doubling your height to keep the original ratio. You will get quality
enhancement because the compression artefacts are much less visible. See all
reasons and drawbacks for resizing
up before encoding. |
(11) |
50 fps
720x540 |
Field Bob
(Method 4a) |
152.8%
|
Resize up (increased height until it
matched 4:3)+Sharpen |
The same applies here as to (10). The 2 differences to above
are: 50fps, resizing is
bicubic instead of just duplicating.
I would definitely use (11)
instead of (10), because for
15 percentage points more, your quality will be 4 times as good.
The drawback is that your computer may be too slow to decode the
movie. In that case you may use (17) or (18).
(11) Duplicate Field 1
(11),(17),(18) Discard Field 2 and resize by bicubic.
|
(12) |
50 fps
720x540 |
Field Bob
(Method 4a) |
158.6%
|
Sharpen+Resize up (increased height
until it matched 4:3). So the same as above but sharpened first |
This is just to show that the order of filters matters when compared to the
one above. The result is pretty the same though. |
(13) |
50 fps
720x288 |
Field Bob
(Method 4a) |
98.3%
|
Sharpen+a bit of the "Smart
Smooth" filter |
Don't do it. You lose a lot of details, compression is slow as hell
(14 hours
for 42 minutes film) and you don't gain much. If "saving filesize thru
smoothing" is really needed, use DivX internal smoothing filters
instead. They are optimized for to save filesize via smoothing. |
(14) |
25 fps
720x576 |
Smart Deinterlace |
130.1%
|
Smart deinterlace Filter for Virtualdub
by Donald Graft. |
Options: "Frame-and-field differencing", "Compare color
channels", "Use bicubic", "Motion threshold: 15",
"Scene change threshold: 100"
Please note that this is a very good filter, that leaves you with a 25
fps (thus unfluent) movie though.
|
(15) |
50 fps
720x576 |
Deinterlace Smooth
(Method 4b) |
195.0%
|
"Deinterlace Smooth" Filter for Virtualdub
by Gunnar Thalin. |
If you are a quality fan then this could be the best quality deal for you. This filter is unbelievably good, but usually leaves you with twice the filesize (well, not always) and twice the height (=original height). This could make the movie unplayable (PC too slow). Besides the encoding itself is slow.
I love the results though. Brilliant, excellent, the way all video should
look like: Fluent movements, sharp still scenes (backgrounds, unmoving
objects).
To give you an idea, how big files are: I encode my DVB recorded MTV
videos (528x576) with (15) and they are
between 30MB and 170MB each. The filesize is mostly depending upon
a) How sharp is the source material (DivX loves blur).
b) Are there black letterboxes at the top and bottom? (Less to encode).
c) How many movements are there?
d) How dark is the overall video? (DivX loves darkness). So the
letterboxed, quite slow, unsharp, sometimes dark music clip
"Robbie Williams featuring Nicole Kidman - Somethin' stupid" (a
cover of Frank Sinatra's hit)
is only 10MB per minute (= like uncompressed .wav) while the non-letterboxed, many movements
containing, quite sharp, bright music clip
"Red hot chili peppers - Aeroplane"
is 40MB per minute. I faked Nicole's legs by the way. You may also
see How Video Filesizes are affected by the
Source. |
(16) |
50 fps
320x240 |
Deinterlace Smooth
(Method 4b) |
45.2%
|
Like (15)
but resized to 320x240 |
Unbelievable, that this resolution can give you such a sharp picture (but the encoding is quite slow). Small size, sharp picture, fluent movements. Only
15 percentage points bigger than (9), but at least 4 times the
quality.
This could be the quality/size/fluidity deal for you. |
(17) |
25 fps
720x540 |
Discard Field 1 |
99.6%
|
Discard and resize height up until
width:height matched 4:3 |
The differences to
method (10) are, that you
resize by Bicubic Resizing instead of just duplicating the lines
and that you resize to a smaller height than (10).
This gives you a better quality as the pictures show (see (11)).
AND: You get the correct aspect ratio. But it's still only 25
frames instead of 50, so I wouldn't use it. |
(18) |
25 fps
720x576 |
Discard Field 1 |
109.9%
|
Discard and resize up by bicubic
resizing to double the height. |
|
The only difference to
method (17) is, that you resize to the same width/height like in (10). This gives you a better picture but still results in a
smaller filesize. |
(19) |
50 fps
720x576 |
Avisynth's internal BOB filter
(Method 4c) |
177.6%
|
Use "bob" in the Avisynth
script: Method 4c) on the Deinterlacing
Homepage. |
|
Why use it? Nearly the same
filesize as (15), but not near as good. Use (16) instead,
if you want to decrease filesize effectively while still keeping
very high quality.
This filter leaves you with twice the height (=original
height). This could make the
movie unplayable (PC too slow). |
(20) |
50 fps
720x576 |
Smart Bob |
223.6%
|
"Smart Bob" filter for
VirtualDub by Donald Graft |
|
Quite good filter. About
twice as fast as (15) but a
little worse quality and a bigger filesize. However in some cases
this filter may produce smaller files than (15). |