Poor quality converting DV to MPEG

DV2MPEG · Post by **DV2MPEG** » Sun Jul 01, 2007 11:18 pm

Hi all!

Can anyone help me?

I usally convert DV (AVI) files to MPEG (DVD variable 6000) on VideoStudio 8, on an old P3 winXP PC. 4:3.

I now have a new PC running Vista. I installed VideoStudio 11+ trial on it, looks quite good

. But when I converted a DV file to MPEG, it is blocky, no way as good quality as VS8 on my old XP PC. Why is that?

I have changed the Video rate higher (eg 8000kbps), I have changed it to Constant instead of Variable. I have changed the speed/quality ratio higher, I have tried changing he Audio format from LPCM to others, non of this has made a difference. The output is still poor. Why?

I loaded up a good mpeg that I converted from my VS8 on XP, cut it on VS11+ then 'Created Video File' and selected 'Same as First Video Clip', this gave the proper good quality output, was not blocky, was fine. Does this mean that there is a settings or something I have missed?

Please help!

thankss

Post by **Ken Berry** » Sun Jul 01, 2007 11:22 pm

The Field Order? Your original DV footage would be Lower Field First. Perhaps the default project properties you chose did not have the same Field Order. Blocky artifacts can sometimes indicate the wrong field order was used... Using already processed mpeg-2 with the 'Same as first video' settings would on the other hand ensure that the same Field Order was used throughout.

DV2MPEG · Post by **DV2MPEG** » Mon Jul 02, 2007 6:29 pm

thanks for the reply

but unfortunately ive tried that already, hasnt made any difference.

One thing ive noticed is that when converting a 1.40min segment to mpeg on VS11+ vista, file is 88.5MB. But when converting it on VS8 XP, size is 90.7MB. Im not sure if im missing something or if this is how VS11+ is supposed to perform.

Ive run another test. I installe VS8 alone on Vista, it failed to convert with an mpeg error. so i uninstalled that, then installed VS11+ first then installed VS8. It has managed to convert it to mpeg, but with the same poor quality as VS11+... this doesnt make sense

So VS8 on old XP is fine, but VS8 on vista is not? or maybe its because its using VS11+'s drivers codecs, as VS8 didnt originaly work on vista before i installed VS11+.

any other suggestions??

please help

Post by **Ken Berry** » Mon Jul 02, 2007 10:46 pm

Just on the VS8 point, it is not Vista compliant, so you can't draw any conclusions from its results on Vista. Only VS11 is supposed to be fully Vista compliant, and VS10 was mostly compliant with the Vista update patch.

Apart from that, though, I can't think of anything new. Could you right click on one of the blocky mpegs within VS and copy down its properties here please?

sjj1805 · Post by **sjj1805** » Tue Jul 03, 2007 3:51 am

You need to double check all the available settings.
Not just the bit rate but also things like non-square pixels, screen dimensions e.g. 720 x 576 (PAL) or 720 x 480 (NTSC)
flicker reduction (If using still images - in VS11 this is set in preferences)
Field Type (Upper/Lower/Frame)
Format 4.3 -v- 16.9

Simply double check everything.

Svuppe · Post by **Svuppe** » Tue Jul 03, 2007 7:37 am

Last night, just before I went to bed, I think I noticed the same problem in a newly created MPEG2 file. Compared to older footage made with VS9, it does seem more blocky, mostly around high-contrast edges. Almost as if there has been applied just a tad to much sharpening.
However, I'm not sure the bitrates and every other setting were the same, so I will try to make two completely identical conversions with VS9 and VS11+ tonight.

DV2MPEG · Post by **DV2MPEG** » Tue Jul 03, 2007 7:06 pm

thanks for the reply guys

I have now tried unticking flicker-reduction, has made no difference. As for all the other settings, I have already checked. unticked and ticked non-sqaure pixels, tried different field types.

Below I have pasted the properties of both. There only seems to be 2 differences between them.. not sure how to upload images, il just type up some of the info:

Differences:
File size=
VS11+: 30,528
VS8: 31,286

Video, comp. ratio=
VS11+: 42%
VS8: 41%
----
Everything else is the same:
file format: PAL DVD
duration: 33.840 secs

video type: MPEG-2 Video, Lower Field First
total frames: 846 frame(s)
attributes: 24 bits, 720 x 576, 4:3
frame rate: 25.000 frames/sec
data rate: Variable bit rate (Max. 6000 kbps)

audio type: LPCM Audio
total samples: 1,624,320 Samples
attributes: 48000 Hz, 16 Bit, Stereo
----

all help is appreciated

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Svuppe · Post by **Svuppe** » Wed Jul 04, 2007 8:31 pm

I have now tried to make a comparison between VS9 and 11+, and to my horror, it seemed like VS9 also started to make bad-looking MPEG2 files. But read on....

It turns out that it isn't the generated video at all, at least not in my case. VS9 as well as 11+ makes very comparable, and good outputs. Instead it is WinDVD that can't play these files in a proper quality. My VS9 is on my old PC where I use a very old version of PowerDVD, which doesn't have these problems. Therefore I thought VS9 was better than VS11+, when in fact it was the player that came with 11+.

Here is how a MPEG2 file from VS11+ looks in three different players:

WinDVD (bundled with VS11+), running under Vista:
http://www.ejberg.dk/temp/windvd2.png

PowerDVD (old version, 3 or 4 i believe), running under Win XP:
http://www.ejberg.dk/temp/powerdvd.png

Windows Media Player, Vista:
http://www.ejberg.dk/temp/wmp.png

It looks like a deinterlace problem in WinDVD. I have tried all three settings for deinterlacing (auto, bob, weave) without improvement.
Funny thing though: WinDVD has no problem playing the raw DV file in perfect quality, even though this is also interlaced.

Svuppe · Post by **Svuppe** » Wed Jul 11, 2007 8:10 pm

Svuppe wrote:It looks like a deinterlace problem in WinDVD.

I have to make an update of this observation. The file I tested with was an MPEG2 made with VS11+, and played back directly as a standalone MPEG2 file. Now I have finished some other editing and made a DVD. This DVD is made without recompressing this MPEG2 file, but the finished DVD plays fine in WinDVD without the previously mentioned problems.