macroblocks

[tatester]

I have just encoded an avi file to DVD which is 2hrs 42mins 48sces long in Tmpgenc using the two 2pass VBR ecoding process and on my PC the movie looks fine however on my tv especially in dark areas there are very noticeable macroblocks.

I haven't used the 'soften block noise' option and I was considering re-encoding the movie again with it enabled. Is it worth it and is there any other option worth tweaking with to improve the quality?

Thank is advance for any help!

[guns1inger]

I am assuming this has been compressed to fit on a single-sided, single-layer disk, so at 2 hr 42 min 28 sec you are using a pretty low bitrate. Enabling the filter may help a bit, at the expense of time, however trying to fit almost three hours on a disk at Full-D1 without artifacts is a big ask (nigh on impossible, really). If they are truely that annoying after the filter, then your best option is to split the movie over two disks, or encode for a dual-layer burn instead.

[tatester]

Is it possible to convert the avi file to CVD resolution standards i.e 352 x 576 and still burn it as a DVD in order to reduce the artifacts or would this make the file too non-standard.

It's just that I had a movie that I borrowed from a friend which was burnt as a DVD but when I checked the resolution it was 352 x 576 and it was very good quality and it was 2hrs 15mins in length.

[Richard_G]

If you check the What Is DVD at the top left you'll find that 352x576 is DVD compliant. I use it for analogue VHS captures and anything over 2 hours. Set the bitrate for around 3500-4000kbs and the quality will be fine. As you have halved the frame resolution, you can halve the bitrate for similar quality. Therefore using 4000kbs will give you similar quality to using full resolution at 8000kbs. The only thing I've noticed is that using this resolution with a decent quality source (I sometimes capture digital TV) the image looks very slightly soft.

[spiderman2k1]

You be better of encoding with CCE.

[mats.hogberg]

What bitrate is the AVI to begin with?

/Mats

[Gurm]

Different players handle half-d1 differently. Some well and some not so well.

[tatester]

What bitrate is the AVI to begin with?

/Mats

The avi file is 480 x 352 and has a bitrate of 1064 Kbps. Don't know if this is low for avi as I haven't encoded in avi before. It looks great on my PC though.

[junkmalle]

Make sure your black levels are correct. The blackest blacks should be near zero on an PAL DVD.

[ZippyP.]

The avi file is 480 x 352.

Use 1/2 DVD to match your source, the upsizing is causing macroblocks.

[mats.hogberg]

480 x 352 and has a bitrate of 1064 Kbps

More than adequate, I'd say. But then again, macroblocks in dark areas are common even on commercial DVDs in my experience. I agree with the rest - resize to 1/2 D1 (=CVD). It's a standard DVD resolution. As a rule of thumb, never resize up - go for the nearest smaller DVD resolution when resizing and reencoding from AVI.

/Mats

[thor300]

I agree with spiderman here, tmpgenc isnt so great at low bitrates, cce can do noticeable better, and using avisynth to resize up would give a little improvement even when encoding with Tmpgenc. Its still a very long videofile, so half D1 will most likely look considerable better.
BTW, its not the upsize that causes macroblocks, its the low bitrate.
The rule of thumb by Mats is true for long videos like this, but generally you will have improvement with a Full D1 if using BicubicResize; it will interpolate when resizing up. You will have to choose between Blocks and Resolution. I would no doubt lower it to half D1, if it were less than 2 hours i would use AviSynth to make a Full D1.