Converting VCD to DivX is it worth it?

[BluDChyLD]

I've got a 3 disc rip of a film on a VCD. I haven't got a DVD player so Im thinking of just ripping it to a DivX. The film is about 3 hours long though so it'll be a 2 cd DivX anyway. Is it worth re-encoding to DivX or should I just stick to VCD? If there's no quality loss I might aswell encode it to DivX...
Any suggestions?
BluDChyLD

[FactorM]

i think there will be a quality loss, every re-encoding has loss of quality as result.

[movmasty]

you could also get a better quality with less size re-encoding,if you apply the right filters.

and is possible to fit 3 hours on 1 CD at vcd res!
i have a CD with 8 hours of movies 320x240!(movies are at 12fps thought but would be still 5 hours at full fps)
and maybe better quality than the original mpgs!

and mpg of 352x288 and 352x240 dont have the 4:3 ratio,you could fix that,
and remove black bars too, and fix colours(green shift).

the correct size for bot 352x288 and 352x240,is 352x264,
crop some noise up and down to make 352x256 and have a height divisble for 16.
you could also do 320x240 or 400x288, depends from movies compressibility,
or like 320x192, 352x208, 400x240, if there are black bars up and down.

to resize(after cropping),do this way:
if you have to make,e.g., 352x208, resize up to 704x416 with precise bilinear or bicubic 0.6, then resize to 352x208 with p. bilinear.
then if you need more sharpness, you could use levels filter at,say,12-1.00-245.if movies are too lightned use 18-0.95-255, if too dark 5-1.07-235.
or use unsharph mask, only for the center of the screen, ray to 5,strenght 12-20, and threshold to 1.
is better to use avisynt to resize and apply spatial soften.
unsharph mask is only available in nan/virtual-dub.

then use nandub to encode.
watch the movie frame by frame, and if image moves only every 2 frames,it happens often, decimate frames by 2.
with vcd source u could use drf at 4-7/8 in nandub.
or also do a fast one-pass encode in vdub with dvx fast motion,even using drf 5-5 in nandub one pass, will give less size.

[dragoman]

Cool! I always wanted the ultimate guide to getting 8 hrs of crappy quality video on one cd!

I guess I can just chuck my high quality, high-res movies out the window and start encoding at vcd resolution.....

Thanks, man, I was wondering how to get Titanic and Braveheart to fit on one cd!!

dragoman

BTW, I'm just kidding here....:)

[Darksoul71]

@movmasty: Doohh, you´re an encoding master: 8 hrs on 1 CD ? 12 FPS ? Why didn´t you choose 4 FPS ? May be you could have fit 24 hrs on a CD ? :D

@BluDChyLD:
You can reencode to DivX without too much loss in quality. VCD itself is very bad source material but on TV you wan´t notice a different between DivX and VCD.

Don´t listen to stuff like this:
and mpg of 352x288 and 352x240 dont have the 4:3 ratio,you could fix that,

Both PAL (352x288) and NTSC (352x240) have 4:3 ratio just MPEG1 pixels for playback aren´t square like AVI pixels.
Correct resizing without dropping any lines:

PAL: MPEG1 352x288 -> AVI 384x288
NTSC: MPEG1 352x240 -> AVI 320x240

-Merge all VCD files to one big MPEG1 file with TMPEGEnc MPEG tools.
-Load this big MPEG in Nandub
-Resize like discribed above
-Crop away any black borders
-Optionally you could apply smart smoother in order to get rid of compression artefacts by the MPEG source material.

Encode with Nandub like discribed in doom9´s guides.

BTW: I wouldn´t touch the videos brightness unless it is VISIBLY brighter / darker than your normal material.
VCDs look often much darker on monitor than on TV screen.

Just my two cents,
D$

[Difflam]

> @movmasty: Doohh, you´re an encoding master: 8 hrs on 1 CD ? 12
> FPS ? Why didn´t you choose 4 FPS ? May be you could have fit 24
> hrs on a CD ?

Hey!!!! I'm tha squeezing movies down to absolute crap quality master!!! This guys got nothing on me... Once I encoded a 2 hour movie down to only 10 MB by using 1 fps, setting the resolution to 80 by 60, and using DivX quality based encoding at 0%. Hell yeah. Didnt bother with audio, who needs it when you can have 70 subtitled movies on just one cd???!!!!

*ps all the above was just a joke*

[movmasty]

@Darksoul71, read:
I've got a 3 disc rip of a film on a VCD. I haven't got a DVD player so Im thinking of just ripping it to a DivX
is clear that BluDChyLD plays movies on pc, then mpg pal and ntsc clips will result out of ratio,converting in divx he can fix this.
really you didnt need to write that "wrongest" dissertation.....

>just MPEG1 pixels for playback aren´t square like AVI pixels.
this is a very common mistake,tv pixels are NOT rectangular!
isnt the shape of pixels, but their density on the screen!
and if pal SEEMS to have an asymmetric hor and vert res, b/w ntsc had perfect "square pixels"!, meaning a symmetric density.
the res of most ntsc tv screens was 640x480,not 704x480, so it is 4:3 and "square".
consider also that the tv signal,althought has linees,hasnt an horizontal number of pixels,because it is an analogical signal,
it has a "dept" that can be rendered optimally with ~640 dots on the screen(the nyquist factor),
then some cheap tv set can have even 500 dots horizontally,and some good one up to 672(but is not sure if it will look better than 640).

Then came the pal, it is newer than ntsc, and was built thinking to colour transmissions.
colour screens have 3 dots(R G B), where b/w had one, so is 640x3=1920!
althought you cant consider that definition gets 3 times bigger,
the most common opinion is that details are rendered 2 times better in colour screens.(i,personally, think that maybe it is 1.75)
in fact colour tv has very better sharpness than b/w,BUT, only in the horizontal direction.
a colour ntsc screen then has like 1200x480 dots, very asymmetric.
pal tryed to correct this a little,by giving the saved bandwidth of the lower fps(25/30), ALL to the vertical res.
never thought about why pal is 640x576(yes, pal has EXACTLY the same hor dept than ntsc!) and not a symmetric 704x528?

Then came digitalitation,the fact that ntsc and pal are digitalized both to 352/704/720 pixels, means 2 things:
1)pal and ntsc have the SAME horizontal res!
2)since the colour sign. is more detailed,the horizontal digital res was setted a little higer that the nominal tv res of 640.
note that 704 is the average of 640 and 768, while 720 is not, but this is another subject.......

now, where are yours "not square pixels" :confused:

still,if tv doesnt have hor pixels, a digital,not interlaced, movie(and VCD format isnt interlaced!) doesnt have "linees",
it has just same kind of pixels hor and vert!
then you can resize all as you like.
and often you have to cut bars, no "linees" to keep then,
who convert dvd to 640x480 or 768x576?
we all use 640x352 or 640x272...

>"Correct" resizing without using any brain:
PAL: MPEG1 352x288 -> AVI 384x288
NTSC: MPEG1 352x240 -> AVI 320x240

but.....if a ntsc vid has excelent quality, why reduce its res??
bring it up to 352x256, or even 512x384!!
and is a pal mpg1 is very bad, why magnify errors??
reduce to 352x256, or even 320x240!!
and if you play a divx of 352x256 on tv, your tv output will add the needed bars.....

> Why didn´t you choose 4 FPS ?
because..........
optic says that images last on eye about 1/10 of second
then 12fps IS a movie, 4fps is NOT

>May be you could have fit 24 hrs on a CD ?
with 8 hours the divx versions have still better quality than the sources i encoded from.<----fullstop

>Merge all VCD files to one big MPEG1 file with TMPEGEnc MPEG tools
well, you just said that is better to not fit too many time on one cd,
then you say to merge all as 1st step, then resplit again???
do the 3 parts separately!
just 1/3 of the time for each step! do when you have free time,
and be sure that the 3rd encode will be better of the first!
then merge the divx with virtual dub.....

>Resize like discribed above(that is "without dropping any lines" i guess??)
>Crop away any black borders(uhmmm, dropping some line i guess??)
if you resize before to crop...you will spend time to resize black bars......and with a long merged movie....

>Optionally you could apply smart smoother in order to get rid of compression artefacts by the MPEG source material....and reduce your movie like a cartoon, you know, those flat faces.....
to smooth use the spatial smoother of avisynt!
the smoother filters of vdub are not the cream(there is some new better thought)

>Encode with Nandub like discribed in doom9´s guides,then,please, explain all those verbose guides to me....(uhmmm, not sure if i reported this exactly.....)

[movmasty]

@dragoNman
i encoded a good movie that i like(Conan the barbarian)
on 3 CDS, that is ~40min each cd.....

why then make a cd of 8 hours ??

well, the sources were many clips of low/medium quality,
some of 240x180, or even 160x120.....
some already at 15fps, or even 8fps....

i made the quality something better than the sources
then i saw that one CD got filled with 7H:53minutes....

......im very sorry of this.......... :(

[dragoman]

BTW....I'm just kidding here. :)


Read my post......I really don't care and have no reason to critizize you. I was just making a joke.

dragoman

[Darksoul71]

@movmasty: READ :)


is clear that BluDChyLD plays movies on pc, then mpg pal and ntsc clips will result out of ratio,converting in divx he can fix this.


I agree. MPEG PAL and NTSC clips will result in "out of ratio" AVI, if you don´t correct the res because AVI has square pixels and MPEG doesn´t (at least the image is "stretched" on TV or by your software DVD player).

I will NOT discuss any resolutions stuff on analogue sources. I´ve seen way too many discussions on german video boards on that.

I´ve got to say only this:
NTSC capture res is (for "normal") 640x480 with both fields

PAL capture res is 704x576 (PAL signal without 8 Pixel border left and right/ Pixel aspect ratio 1.091:1) or 720x576 (PAL signal WITH 8 pixel border left and right / Pixel aspect ratio 1.091:1) or 768x576 (equivalent to 704x576 but in 1:1 Pixel aspect ratio)
PERIOD.

PAL VCD is basicly the "quater" of 704x576 and only one frame (=288 lines). For NTSC VCD 352x240 is also basicly 320x240 and the "quater" of 640x480 with only one frame (=240). When I talk about lines I MEAN lines.

So to quote you:
>the correct (stupid) size for bot 352x288 and 352x240,is 352x264,
OK, for NTSC the resize filter has to "invent" (read: duplicate) another 24 lines. For PAL you are dropping 24 lines. Superduper.... :)
Dropping lines means loosing details. Duplication of lines meas to copy information.

well, you just said that is better to not fit too many time on one cd,
then you say to merge all as 1st step, then resplit again???
do the 3 parts separately!

Well, for setting up Nandub/VDub/etc. It´s definitely easier opening up one file and encode in one step. But this is up to BluDChyLD to decide.
if you resize before to crop...you will spend time to resize black bars......and with a long merged movie....


This takes long ? Come on. Even on my old PIII-850 I could encode quater sized source material in above realtime. A 3 hour movie will result in max. 4-5 hrs 2 pass encoding duration.

(Read my last line: Just my two cents=it´s just my personal opinion/knowledge)

optic says that images last on eye about 1/10 of second
then 12fps IS a movie
My eyes say. Everything below 24 FPS is CRAP. I even notice differences between a 50 Hz and a 100 Hz TV or between a monitor set to 75 or 85 Hz (and above).
Don´t start basic discussions.

>Optionally you could apply smart smoother in order to get rid of compression artefacts by the MPEG source material....and reduce your movie like a cartoon, you know, those flat faces.....
to smooth use the spatial smoother of avisynt!
the smoother filters of vdub are not the cream


Any smoother can "smooth" out too much details if you don´t know how to use it.
You can use Smart Smoother with low radius and middle strength to get rid of noise & compression artefacts. I agree that some of the VDub filters aren´t as powerful as their AVISynth variants.

to resize(after cropping),do this way:
if you have to make,e.g., 352x208, resize up to 704x416 with precise bilinear or bicubic 0.6, then resize to 352x208 with p. bilinear.


Great stuff here: Upsize and then downsize again ? LOL

To make a long thing short:
I really don´t care how you encode your movies. You can even encode in 160x120 and 12 FPS to real video if this is visualy pleasing for you.

I just wanted BluDChyLD to avoid some mistakes you told him (resolution and frame rate stuff).

Ask the guys over at the capture forum what they think of 12 FPS :)

-D$

[Doom9]

come on.. everybody who knows just a little about digital video knows that a recompression is lossy (unless you "compress" to a lossless format like huffyuv in which case one should rather speak of decompression).. that being said.. this thread is really a good example of what simply doesn't belong here.