x264 encoding low bitrate don't like quantizer

[albesp77]

Hi to all, i'm try to convert a mpeg2 1080p progressive video to h264 format, i want to obtain a good video that fill a dvd5 disc, but the file that i obtain using megui with x264 dual pass hq profile have a quantizer medium of 26-27 that i don't like very much, i know that using some avisynth script to filter (ex. remove noise, luma filter) i can obtain better results, but i'm totally newbie and i don't know which kind of filter i can try, can anyone explain me better what can i try ?

[kuchikirukia]

Post a clip and your MeGUI log file.

Out of curiosity, what's the size/length of the MPEG2, and what are you doing with the audio?

[albesp77]

i don't have log here with me, original mpeg2 is about 35gb, audio is converted to mono aac 192kbps (is only dialogue)

[kuchikirukia]

Mono dialogue you should be able to go to 64k without much issue. Without a clip it's hard to suggest anything to do to the video to clean it up. Bilinear resize to 720 is probably your one-stop shop to get what you want.

[benwaggoner]

How does the MPEG-2 look? If you've got obvious blocking, using a deblocking decoder like the one MeGUI's File Indexer (dgdecode) makes available can help, albeit by making the video softer. Tossing on --nr 300 can help if the source is noisy, even more if there's lots of grain or other temporal nose.

A DVD-5 is about an 8x reduction from your source, but I've generally been able to get a decent 90-minutes of 1080p24 in that size with some care.

Using VBR audio can help as well; soundtracks can often have silent parts, so a Constrained VBR targeting 64 Kbps might only give an ABR of 32-48. But getting the video settings tuned in is where the money is.

If there are significant end credits, setting the credits start point in MeGUI can also save a decent amount of bits.

Anyway, In the Advanced mode of MeGUI, copy the command line section and paste it here. That's where the important stuff is.