Expected MPEG2 Quality

[masami]

I've been trying to find a thread about exactly what quality i can expect from converting DV-AVI to MPEG2, but have not been able to.

I am currently using Tmegenc plus, and have apparently configured it to produce the highest quality results (thanks to a few websites). However, the picture quality is a little pixilated.

Should i expect to see the same quality as the orginal DV-AVI (from camcorder), which is pixle free?

Any suggestions?

thanks for any help!

[edDV]

How are you viewing the result?

And define "pixelated" and describe the material being encoded from DV.

[jimmalenko]

Pixelation is normally a result of insufficient bitrate, or it could even possibly be noise that you're experiencing. Can you put up a screenshot so we can all see what you see ?

[Richard_G]

As Australia uses PAL, the quality of a DV-AVI encoded to MPEG2 should look no different to the original DV. But only when viewed on a TV and if the bitrate is high enough. For top quality you need to be encoding at full resolution (720 x 576) with a bitrate of no less than 9000kbs.

[masami]

im viewing the results on a tv - in australia.

at the moment i am encoding someone speaking on a microphone at the front of a bus. But i want to encode a movie i put together of a trip overseas.

By pixilated i mean the picture doesnt look 100% clear or smooth, its a bit grainy in places, mainly when movement occurs. Its not like a dvd you buy from a shop.

Using 2pass VBR, 10bits,
Average Bit rate - 7000
Max bit rate - 9000
min bit rate 2000.

Im not sure how to do screen shots...

You are guys are great!

[edDV]

For screen caps I like Gadwin Printscreen (free)
http://www.gadwin.com/purchase/pricing.htm

take the screencap and plug into this line

[masami]

i doesnt seem to be working, but i'll see if this works... attaching file to this msg.

[masami]

2nd try

[jimmalenko]

Whqat did you do with the PNG file ?

[masami]

3rd time lucky

[masami]

4th

[masami]

5th try

[jimmalenko]

File has to be under 150KB, and I find that JPEGs are probably the best.

Email it to me at jim.malenko@gmail.com and I'll upload it for you if you like

[masami]

[masami]

it worked!! thanks!

[jimmalenko]

What program did you use to take the screencap in ?

And is that from the AVI or the MPEG-2 file ?

Did you deinterlace ?

[masami]

used windows media player.

its and mpeg. would it help if i did an AVI, for comparison?

i didnt do anything to the settings in media player. when i converted im pretty sure i used interlace

[jimmalenko]

OK, getting somewhere !

used windows media player.

From memory WMP does not deinterlace on the fly, so that would lead me to thinking that either your source is progressive or you deinterlaced in your conversion. Either that or you happened to get a still of a frame that shows no interlacing lines ...

its and mpeg. would it help if i did an AVI, for comparison?

Sounds good

[masami]

the AVI, this was the closest match i could get to the first screencap

[masami]

[masami]

and again

[jimmalenko]

Note the red squares:



no dashes, no spaces, no nothing in the filenames.


... and BTW, just edit your post - no need to keep posting new posts

[masami]

[masami]

[masami]

the last pict is a screen shot on the AVI. the second last is a mpeg screen shot

[jimmalenko]

Or do a side by side, with a bit of resizing so that they're the same height:

[masami]

another question...

if i use "System", instead of "ES", would that make a huge differnece? i just relaised that people have suggested using ES, but i havent been able to check its quality as the DV authroing progs say there is an audio error? could the bit rates be to high?

[masami]

For some reason the screen cap want let me capture from Media Player anymore. i just get a black area, with no picture.

Have you got any other tips? should i be able to get quality like that of a hollywood dvd? can you recommend any other freeware converters?

[lordsmurf]

if i use "System", instead of "ES",

I suggest learning what all these settings mean, rather than blinding clicking on things and guessing. You need to do some reading, there are several guides on TMPGENC that explain all these things.

ES is elementary streams (audio OR video).
System is a system stream (audio+video).

[edDV]

The major problem with that picture is excessive dynamic range (white to dark) for a 8 bit video system. It looks like the camera made the right decision to expose the foreground properly and let the background go into clipping. The result is the background lacks any gray scale to moderate edge artifacts. This is an extreme case sample.

Be specific as to which areas of the picture are concerning you. You have a better view than these stills give us. Most problems with MPeg show up in motion.

If pros were shooting that scene they would have put a bright keylight on the subject's face and probabbly blocked that background. That is what they have do to make video fit into 8 bits. If they couldn't avoid the background, they would expose it by switching in a neutral density filter and then use heavier lighting on the subject.

Most people think lighting is used to compensate for darkness. The little appreciated secret of the pros -- lighting is used to control contrast.