I Just Don't Get it ???? ;)

[EnNiS]

I dont frikin get it
why does every1 love svcd so much, rather than vcd?
i love vcd, tried svcd, dont a big diff in quality, and a big diff in compatibility. I am sticking with my xVCD's.
What i want to know is If you have an xvcd and an svcd template
and u change the bitrate for both to say, 1200, would they both be the same quality on a dvd player?
thanx

[fossil]

i personally think SVCD is better for my anime dvd rips. cus it pereserve all the quality or most of all of the original DVD.

[Vejita-sama]

VCD = MPEG1 352x240 video at 1150kbit/s
SVCD = MPEG2 480x480 video at 2520kbit/s

SVCD is superior to VCD. However, at the same bitrate and resolution MPEG1 looks the same as MPEG2. That is video quaility wise. What makes MPEG2 'better' than MPEG1 is that MPEG2 supports: interlaced source, multiple audio streams, selectable subtitles, multiple angles, etc.

Further, more standalones support VCDs (and xVCDs) than SVCDs. So yes, making xVCDs (either higher bitrate or resolution) is a good way to go (unless you have a true interlaced source).

[ZippyP.]

VCD = MPEG1 352x240 video at 1150kbit/s
SVCD = MPEG2 480x480 video at 2520kbit/s

So SVCD has a higher resolution which makes for much better picture quality. But, higher resolution has more pixels and demands a higher bitrate in order to maintain quality. An SVCD at a bitrate of 1200 would be very poor quality indeed. Depending on the resolution and quality of the source, sometimes VCD is the better way to go. For high quality sources, the SVCD standard will beat the VCD standard every time, and by a long shot.

[EnNiS]

all right
thats what i wanted, thanx
i have like 50 dvd rips all of which are in vcd or xvcd.
i mostly do the xvcd/one cd vcd trick which i think is fine
they look like a vhs, and are in one cd
rather than having svcd lookin like dvd but takes 3-4 cd's

thanx
cya

[gonzalimator]

MPEG1 is not as high a quality as MPEG2. I did a test for myself and encoded two mpegs with the same bitrate (1575kbps). I found both to be very good quality, but the MPEG2 had a clearer picture. Side by side, MPEG1 looked fuzzy compared to MPEG2. I think that MPEG2 has better picture quality.

I favour CVD's myself. They act like SVCDs and I can take advantage of the smaller res giving me a better bitrate per pixel. I also heard that this half DVD res of a CVD is a recognized DVD format, so if I wish to burn to DVD one day, there's no need to reencode these movies. Sorry, bit of a tangent...

[DJRumpy]

They are technically almost identical. MPEG-2 gains a small lead over MPEG-1 in compression (about a 20% optimization over MPEG-1). Other than additional support features for MPEG-2,and a higher maximum bitrate, they are just about identical.

There is no reason that an MPEG-1 should look any different than an MPEG-2 encoded at the same bitrate, with the same settigns. The MPEG-2 would be slightly smaller.

In regards to your tangent, yes, CVD is resolution compatible with DVD, but you must resample the audio to DVD specification (48Khz). You do not need to re-encode. Just demultiplex, resample, remultiplex.

VCD is also compatible with DVD. Same situation as CVD. Just resample the audio, and it's ready to go.

[groyal]

If you have an xvcd and an svcd template and u change the bitrate for both to say, 1200, would they both be the same quality on a dvd player?

All other things being equal (resolution, field format, rate control mode, audio bitrate, etc.), yes.

MPEG-2 gains a small lead over MPEG-1 in compression (about a 20% optimization over MPEG-1).

MPEG-1 and MPEG-2 handle progressive frames identically, so neither has an advantage in that respect. But MPEG-2 handles interlaced frames using alternate scanning and field-based motion estimation, so it loses compression efficiency in return for the extra capability.

There is no reason that an MPEG-1 should look any different than an MPEG-2 encoded at the same bitrate, with the same settigns. The MPEG-2 would be slightly smaller.

An MPEG-1 coded CBR at 1200 kbps is the same size as an MPEG-2 coded CBR at 1200 kbps. If your MPEG-2 files come out smaller it's not because MPEG-2 is more efficient, but because you're bleeding bits out of the picture by setting your VBR minimum bitrate too low.

[DJRumpy]

Setting a low minimum doesn't bleed out bits. The AVG setting is the determining factor of overall quantization. The min and max just set the scale. Your right though, the AVG setting would always give the same size output. I should have said '20% coding efficiency', not compression.

[DJRumpy]

Hmm...come to think of it, the MPEG-1 standard didn't even support VBR. That came with MPEG-2.

[energy80s]

However if you want to make "out-of-standard" xVCD's then you can have VBR interlaced fullscreen MPEG1 that looks great. This is what Kwag (with his KVCD templates) has built his empire on. The downside is that they aren't that compatible, what plays on one machine might not play on another one.

[DJRumpy]

I've never tried a VBR MPEG-1. I wonder if any newer specs for VCD ever supported it? I never encode to MPEG-1 anymore. It was easier to upgrade my home player to something a little newer (read: compatible) with the other formats.

[groyal]

However if you want to make "out-of-standard" xVCD's then you can have VBR interlaced fullscreen MPEG1 that looks great.

MPEG-1 has no provision whatsoever for handling interlaced pictures; if it did, there wouldn't have been an MPEG-2.

Setting a low minimum doesn't bleed out bits.

Actually yes it does, because if it didn't, the encoder couldn't maintain output at a stable average bitrate.

Example 1:
(a) CBR @ 2000 kbps vs.
(b) VBR @ 1000 / 2000 / 3000 kbps
Result: Files are the same size
Reason: (2000/1) = 2000; ((1000+2000+3000)/3) = 2000.

Example 2:
(a) VBR @ 1000 / 2000 / 3000 kbps vs.
(b) VBR @ 0 / 2000 / 3000 kbps
Result: file (b) is smaller than file (a)
Reason: ((1000+2000+3000)/3)=2000; ((0+2000+3000)/3)=1666.

Example 3:
(a) VBR @ 1000 / 2000 / 3000 kbps vs.
(b) VBR @ 2000 / 2000 / 3000 kbps
Result: file (b) is larger than file (a)
Reason: ((1000+2000+3000)/3)=2000; ((2000+2000+3000)/3)=2333.

I should have said '20% coding efficiency', not compression.

It would be an equal misinterpretation, I believe. If you set a VBR AVG bitrate of 2000 kbps, and the output file is 20% smaller than a CBR file at 2000 kbps, it's not because VBR is 20% more efficient than CBR but because the encoder is extracting too many bits from the picture, causing the file to shrink.

[DJRumpy]

GRoyal, I already stated it wasn't about compression. What are you trolling for? Min and Max define the scale. Average defines how much bitrate is available. Setting a low min doesn't mean that the encoder will drop to that low min. It can, if the bitrate demands are low enough on a given frame. It does so, according to the AVG setting. If the average setting is set too high, then it could delve deeply into the MIN setting to try and satisfy the AVG setting. Again, the average setting sets the rule. The min/max set the scale.

http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html#tag55

It is often remarked that MPEG-2 spent several hundred man years and 10s of millions of dollars yet only gained 20% coding efficiency over MPEG-1 for interlaced video signals.

I was referring to the similar nature between the two, nothing more. I've also admitted my error regarding smaller file size. I misquoted the above.

I do question your examples though. It's been stated to me, time and time again, that any multipass vbr, with an average bitrate of X, will produce the same size file every time.

Example 1:
(a) CBR @ 2000 kbps vs.
(b) VBR @ 1000 / 2000 / 3000 kbps
Result: Files are the same size
Reason: (2000/1) = 2000; ((1000+2000+3000)/3) = 2000.

Agree

Example 2:
(a) VBR @ 1000 / 2000 / 3000 kbps vs.
(b) VBR @ 0 / 2000 / 3000 kbps
Result: file (b) is smaller than file (a)
Reason: ((1000+2000+3000)/3)=2000; ((0+2000+3000)/3)=1666.

Disagree. Avg setting on VBR should produce same file size, because average bitrate for both is the same

Example 3:
(a) VBR @ 1000 / 2000 / 3000 kbps vs.
(b) VBR @ 2000 / 2000 / 3000 kbps
Result: file (b) is larger than file (a)
Reason: ((1000+2000+3000)/3)=2000; ((2000+2000+3000)/3)=2333.

Same here. Avg for both is the same, filesize should be the same. For example b, you've essentially made a CBR file, as there is never any MIN excess bitrate to give to MAX. Min/Max set the scale, but AVG defines what min and max can use. The overall output size of a VBR file is defined by it's average. Regardless of where/when it takes or adds bitrate, it always averages out to exactly the bitrate defined.

[SaSi]

MPEG-2 was designed to be a superset of MPEG-1. This means that if an MPEG-2 encoder uses exactly the same settings as an MPEG-1 encoder to create a VCD, then the file size will be the same and an MPEG-1 decoder will be able to decode it.

However, MPEG-2 allows (apart from broader scope of settings and options), additional tricks in encoding frames (apart from handling interlaced ones). This allows a clever MPEG-2 encoder to use the 1150 CBR better and pack better picture clarity in the same count of bits.

This is why people view a better picture in an MPEG-2 stream encoded at 1150kbps and this is what DJRumpy means by the "20% better efficiency".

And in terms of improvement between MPEG-1 and MPEG-2, 20% better doesn't start to compare the two. (Of course, if an MPEG-2 encoder encodes at VCD restrictions, only a small advancement in efficiency is achievable). MPEG-2 allows for a multitude of other enhancements. In fact the MPEG-2 committee did such a fine job that MPEG-3 was scrapped. MPEG-3 was conceived to be the HDTV encoding standard but the industry realized MPEG-2 was more than enough.

[groyal]

GRoyal, I already stated it wasn't about compression. What are you trolling for?

I'm not trolling for anything: I'm trying to dispel an important misconception. If a VBR encoding is smaller than a CBR encoding at the same bitrate, it's because the minimum is too low, not because VBR is more efficient.

If the average setting is set too high, then it could delve deeply into the MIN setting to try and satisfy the AVG setting.

The AVG is met right off the top: if the average is 2000 kbps, all scenes are quantized equally in order to reach that value. If the encoder then determines a high-motion scene needs more bits, it will apply higher compression to the low-motion scenes in order to get them. But the quantization step-size isn't continuous, it's discrete: a minimum that's too low will yield more bits than the high-motion scenes need, forcing it to throw the excess bits away (same as a lower average). Likewise, a minimum that's too high won't allow the low-motion scenes to be quantized enough, starving the high-motion scenes of bits that are available but unusable (same as a lower maximum).

http://bmrc.berkeley.edu/research/mpeg/faq/mpeg2-v38/faq_v38.html#tag55

At what bitrates is MPEG-2 video optimal? I don't see the relevance. It establishes what would be a good average bitrate for different frame formats, but it says nothing about the appropriate minimum and maximum.

It is often remarked that MPEG-2 spent several hundred man years and 10s of millions of dollars yet only gained 20% coding efficiency over MPEG-1 for interlaced video signals.

I was referring to the similar nature between the two, nothing more.

I think that was intended as a humorous anecdote rather than an establishment of fact, don't you?

I've also admitted my error regarding smaller file size. I misquoted the above.

That was my mistake: I assumed you observed MPEG-2 files being smaller than MPEG-1 files at the same bitrate and concluded MPEG-2's compression was more efficient. If the file shrinks it's because the minimum is too low, which is the point I'm trying to explain.

I do question your examples though. It's been stated to me, time and time again, that any multipass vbr, with an average bitrate of X, will produce the same size file every time.

That's right.

Example 2:
(a) VBR @ 1000 / 2000 / 3000 kbps vs.
(b) VBR @ 0 / 2000 / 3000 kbps
Result: file (b) is smaller than file (a)
Reason: ((1000+2000+3000)/3)=2000; ((0+2000+3000)/3)=1666.

Disagree. Avg setting on VBR should produce same file size, because average bitrate for both is the same.

Yet it happens. File (b) is smaller than file (a) because the encoder extracts more bits from AVG-MIN than it needs to fulfill MAX-AVG, so the file contracts in proportion. Try it yourself.

The overall output size of a VBR file is defined by it's average. Regardless of where/when it takes or adds bitrate, it always averages out to exactly the bitrate defined.

If, and only if, the minimum is as far below the average as the maximum is above.

[EnNiS]

thanx
thats great
i msotly encode my dvd rips at xvcd / vcd because it is so much more compatible
i have 2 dvd players
1 playts svcd, one doesnt.
i tried a movie in xvcd and svcd both the same settings, and the looked identical, if not, the svcd looked worse
the bitrate was at like 1050 or so
thanx
cya

[DJRumpy]

Yet it happens. File (b) is smaller than file (a) because the encoder extracts more bits from AVG-MIN than it needs to fulfill MAX-AVG, so the file contracts in proportion. Try it yourself.

Tried it myself. The two files were EXACTLY the same, down to the byte. Average bitrate defines exactly how large the file will be. Min and max mean nothing as far as final output size.

I'll try a longer (say 10 minute clip), and post the results.

[groyal]

I'll try a longer (say 10 minute clip), and post the results.

Some tips for your second run:

(1) of course you want a sample clip at least 10 minutes long. You're trying to observe an average behavior, so the larger the sample, the more reliable the result.

(2) You can magnify the effect using higher bitrates. 0 / 6000 / 8000 will make the shrinkage very obvious.

(3) Code the clip the first time through using CBR 6000. Note the file size. Add a few VBR passes on top of that using 0 / 6000 / 8000 and note the file size again.

[DJRumpy]

Ran a test on a 10 minute clip (10:25:01). Both clips were 148MB.

For the test, I ran 1 at 0 min, 2000 avg, and 3000 max.
The other I ran at 1000 min, 2000 avg, and 3000 max.

Same size for both. Hopefully this will post. Forum seems to be glitchy today...

[gmatov]

Hi, guys,
What does this all mean to the layman?
If my program says 1150 is standard for VCD, and I get 1 1/2 CD-Rs to a movie back-up, if I enter 1475 as the bit rate, approx 1/3 more, I come out with 2 disks full. Under VCD, is it playable on a DVD standalone that WILL play both VCDs and SVCDs now, using the standards check built into, say, DVDx? It doesn't produce "superb" VCDs, but, for this question, at least it has a compliance checker built in.
Mebbe best I just try encoding one with a higher rate to see if it will play on my machine.
My complaint with MPEG2, SVCD, is that it makes 4 disk backups, whereas VCD makes, mostly, 2 disks. And, it's not the nominal cost of disks, it's the stop, start of it all.
I did a 3 hour disk, Merlin, to VCD, 1150kbps, and got it to 3 disks, with 220 meg on the 3rd. I've gotta do it again, as it lost audio sync on the second, though the third is back in sync. That puzzles the hell outa me. Maybe this is the one I should play with the rate settings. No biggie. I, at least, am having fun with it.
Another, Jericho, was 1 gig at VCD, and 2 gig at SVCD, both at compliant settings, default. It took 3 hours at VCD and 6 + at SVCD.
If I change the bitrate, do I make them unplayable on a standalone?
If these question are too basic for this thread, I'll go back to the noob section.
Thanks,
George

[EnNiS]

no it wil still be compatible like 99 percent fo the time if u change the bitrate
just follow the one cd vcd trick

and u can fit ANY vcd to one cd-r
as long as u dont mind the quality
i can make a near dvd, better than vhs vcd, of a movie at around 90 minutes, on 1 cd-r, with a bitrate of around 900.
anyhing above 850 is good
expirment.
goosd luck
cya'

[EnNiS]

so............

[gmatov]

EnNis,
I don't understand the "so.........""
Should I be asking you something?.
I used DVDx and changed the bitrate to 1850 to fill 2 disks with a rip that only totaled 1.2 gig at 1150.. The quality is 3 times better. Now, how do I get the same rip to 1 CD without going to VHS through a screen door?
By the way, at the increased bit rate, it starts instantly in my Apex, whereas, the compliant ones took at least a minute to recognize. That in itself is amazing..
Now, how do I change it to fit on one disk? It's only about an hour 40. Haven't tried 900, but it should fit, or somewhere near there. When Idid try one, the quality was lousy. Way worse than standard.
Thanks,
George

[groyal]

Ran a test on a 10 minute clip (10:25:01). Both clips were 148MB... Same size for both.

I repeated the experiment (several times, two different encoders) and got the same results as you. I was wrong.

[DJRumpy]

I made the exact same mistake myself. Once I knew how the AVG affected everything, it makes managing my output MUCH easier. Took a long time to learn though. Even the encoder docs are pretty weak on discussing individual settings.

[hustbaer]

@EnNiS: hi!

would you please tell me HOW you make a "near DVD" quality vcd with a bitrate of 900-1000kbps?
i'd really like to know, because i am pretty much 99.99% sure there is no way for an mpeg1/mpeg2 movie with this bitrate to even come close to DVD.

however if there IS, i'd be greatful to learn how - which converter, which pre-processing, etc.

thx, bye,
--hustbaer

[EnNiS]

wel theres ur first mistake
its all inthe bitrate'
well i have done movies at around 700 that look good
just take the avi and use virtualdub to framserve it
it saves a hella lot of time
just open the avi in vdub and change the audio to full procesing mode and click on conversion and change it to 44100 ok
then go to video then click on video -> filters and click on sharpen and make it like 40-55
then go to file -> start framesever and click ok on the window that pops up and then save the new smaller frameserved file as like "video.vdr.avi"
then open tmpgenc and open the new framserved file adn click what u want to save it as and LOAD the proper template (most of the time is NTSCfilm VideoCD) and then click on Settings and do ur necesary changes and set the audio to 160 and set the video typer (under system to Video CD non standard) and then sourcerange it (for best results set the audio to 128 or 160 and sourcerang (cut out) the credits at the end)
so say ur movie is 1:30:00 and u cut out the credits so it is 1:23:00 and audio at 160 u can do a bitrate of: 1142
normaly the final file size would be like 780 so u can add a bit so make it 1164

then go to the advanced tab and click on custom color correction and sharpen
then go to quantize matrix tab and click on soften block noise and make it like 42 for both ok
expirment
mine normally look kick ass
peace
hope this helps
cya

[EnNiS]

gmatov follow the one cd vcd guide

[hustbaer]

hi!

thx for the explanation.
i do it very similar, ... but like i expected - when i say "near DVD" i mean something completely different than you seem to do 8)

and that is the one reason for me to use SVCD - higher resolution, higher bitrate, better quality.

of course if you choose the same bitrate for VCD and SVCD, SVCD will look worse becaust it has higher resolution and therefor a lower bits/pixel value...

whatsoever,
have a nice day,
--hustbaer