Multipass Encoding?

Movie Copy Software
#1

Hi There,

I tried out DVD2ONE the other night for the first time taking the largest movie I have, The Shawshank Redemption which is 7.7GB and set DVD2ONE to do its thing.

Overall, I think the simplicity, speed, stability and quality of DVD2ONE and what it produces is great. The only gripe I have is that there were several spots through the movie which showed easily visable image artifacts. THis is emphasised even more as I watch my movies on a 120" projection screen, so artifacts really do detract from the movie experience.

What I’m wondering is wether these occasional visable artifacts are due to what I’d presume is a single pass encoding in DVD2ONE? I’ve seen the results of a DVD9->DVD5 conversion using CCE, and I was very hard pressed to see any difference in video quality in this and the original, and I’m wondering if this was due to the CCE encode was set to do 3 passes? What’s putting me off the CCE route is that it seems to be extremely involved and complicated, but does seem to produce remarkable results.

If multipass encoding would benefit the video quality in DVD2ONE, would it be worth considering adding a user configurable option, such as a speed<—>quality slider bar so the user has better control of the output quality? I don’t care if the conversion takes 24 hours, I’d MUCH prefer a flawless quality result than a quick encode.

#2

The nature of compressed domain transforms (like the basis of DVD2One) makes multipass encoding make very little (some, but very little) sense.

Since CCE re-encodes (and doesn’t transcode) multiple passes will give it better results.

#3

Aha, gotcha! So it would seem if I’m going to be so fussy, I’m going to have to look at something like CCE to get the results I’m after?

#4

Look at the cost of CCE (the full version) and I think you’ll find it very easy to do a cost/benefit comparison in your head…

But to be fair you have to consider also that CCE is aimed at the professional video market… and it is, very probably, the most powerful, highest quality MPEG2 encoder available on the market. That even holds true when you compare it to expensive hardware encoders.

#5

Originally posted by jdobbs
But to be fair you have to consider also that CCE is aimed at the professional video market… and it is, very probably, the most powerful, highest quality MPEG2 encoder available on the market. That even holds true when you compare it to expensive hardware encoders.

I’m not sure. Have you tried the MainConcept stand-alone encoder? I have both CCE and MC encoders and I like MC better!
It isn’t currently multi-pass, although the next release is slated to be so, but even in its present guise it is at least as good as CCE, much faster (better than real-time on an up to date machine) and a whole lot cheaper.

SirDavidGuy:

Your statement re multi-pass in the DVD2One-type applications is absolutely true. However, the current estimation process to determine the amount of compression needed can sometimes result in the compression wick being turned up rather a lot as the initial estimate proves optimistic and the close of the movie draws near. A second pass strategy would allow a more sophisticated estimation to be made. The original motion vectors - derived from state of the art MPEG encoders used by the studios - are of course retained in programs of this kind and as such do not benefit from even one pass;)

-Pete

#6

I’ve encoded a movie with mainconcept and then I transcoded it with DVD2one.DVD2one gave better results at same filesizes.
There’s a new version of CCE that costs only 58$ and includes 2-pass CBR/VBR encoding, inverse 3:2 pulldown option, flexible GOP setting and separated audio input.
http://www.cinemacraft.com/eng/topic.html#04

#7

Yes, but you musn’t compare re-encoding and transcoding. Re-encoding is wasteful. It throws away all the good work of the original, no doubt highly expensive, hardware encoder, and starts from scratch. Transcoding (DVD2One) simply compresses that original [video only] stream. If you like, it builds on the good work that’s gone before.

What would be interesting is a re-encode of the same material using MC and CCE. I’d like to know which results you preferred then…

-Pete

#8

I’ve done many comparisons between CCE and MC on small videos,not full movies.MC produced blurry video.CCE can only be compared with TMPEG.But TMPEG is SLOOOW!
My personal opinion is that that MC needs improvement.
I think also that it will be better in future.It’s supported by adode :slight_smile: MC=Abobe MPEG Encoder.

#9

I haven’t done a side-by-side comparison. But I have a hard time accepting the premise that a single pass encoder gives results equal to CCE.

Where you have to be careful is that you compare the packages at a given bitrate – there are a lot of encoders that look good with plenty of bandwidth. Even ReMPEG2 gives good results at 4MBps or higher… the exceptional encoders shine on the hardest material.

If you want to see the difference isolate a high motion scene and make comparisons at different bitrates. And always. always, use VBR. A good example is “Cast Away” when Tom Hanks is on the raft and there is constant movement in the water. Most encoders choke on that one when you lower the bitrate.

#10

Why would you lower the bitrate so much - SVCD?

If so, you may well be right. But I have no interest in this format. I think it’s outdated and unwarranted. DVD burners are now cheap enough to tempt the movie enthusiast - as opposed to the hobbyist, who is delighted by the simple act of succeeding in shoe-horning a movie onto a CD.

It’s my far from humble opinion that the old demux/remux cycle now belongs in the history books. DVD2One (and others) can make a good enough fist of the job to satisfy all but the most pernickety - and in a fraction of the time.

‘Cast Away’ is a good example though, especially as it’s so long and therefore tests the duplication application’s abilities to the full.

-Pete

#11

Nope, I haven’t done SVCD in a long time.

I’m talking about the average bitrate. If you have a two hour movie at 4Mbs it would take a little over 3.5GB before the audio is added in – or most of a DVD-R. If you are keeping the extras, etc… you will find that most movies are reduced to somewhere between 2.5Mbs to 3.5Mbs average bitrate.

#12

All the more reason to avoid these extras like the plague, eh?

Apart from a few - a very few - discs, I’ve never understood why there’s all this song and dance about wanting 1:1 copies. Who in the world would sacrifice the main movie’s quality for the dubious ability to access a couple of old trailers? Probably the same people who would prefer three Minis to one S Class…

I must admit, I’m baffled.

-Pete

#13

CCE wasn’t really designed for ripping anyway – it is meant for professional encoding. Another way to really tell the difference is to take some DV input into your system that was filmed by an amateur (lot’s of camera movement). Then do an encode to MPEG2 for DVD burning. The other packages die… CCE pulls it through.

The point is that even though it isn’t always obvious when the rate is high, CCE gives the best quality at any given bitrate (high or low).

I haven’t tried the new replacement for CCE-Lite yet (the $58.00 package).

I guess we’re really getting of the forum topic, though, this forum is focused on DVD2one… which is single pass and one of the best (and clearly the fastest) true transcoder on the market.