How to deal with Artifacts or Pixlates?

[Bonie81]

Testing high quality video source sample clip (V=7800 kbps A=448KHz 5.1)with various encoders, the most of the video encoders (free and commercial) generate visual artifacts/pixlates in the high motion part of the video even at a higher video bitrate>5500+. Only x264, XViD and HcEnc gave comparitive good results with low artifacts. So far none replicate original quality even at video bitrate>original.
Other thing I noticed is picture gets more blurrrred loses details at lower video bitrate.
What makes video encoders to generate artifacts in encoded video?

Video Artifacts / Pixlates



Square Pixels over High Motion

How to deal with Artifacts or Pixlates?
-or-
How to minimize this Artifacts or Pixlates?

However x264 has nice mechanism to lower this artifacts.

[yoda313]

You didn't mention a few important things - what was the source, what was the target resolution?

If you are going from bluray to dvd resolution any codec will lose the high def quality at 720x480/576 vs the 1080 source.

[Bonie81]

yoda313

OOOOoppppppppppppssssssss!
u caught me!

Source was from authentic n original DVD, uncompressed -same sized decrypted chopped 3 min VOB (V=7800 kbps A=448KHz Dolby 5.1) through DVDShrink. While testing was carried out right from 8800 (1000+) than source and stepped-down to 1000kbps in a step of 1000kbps.
so 8800->7800-6800->... ... ...->1000

[jagabo]

How to deal with Artifacts or Pixlates?
-or-
How to minimize this Artifacts or Pixlates?

Use more bitrate. Or use a better codec. Or better settings with the codec you're using. Reduce noise in your source before encoding (noise eats up bitrate). If your source has macroblocking like that use a deblocking filter.

[jman98]

Did you use TMPGenc? It sometimes goes absolutely nuts on scene changes or motion and briefly gives blocky crap like in your picture in its output. Even using higher bitrates won't stop this behavior. I know - I've tested. Before I got used to using AviSynth and HCenc I had to use TMPGenc for a few encodes from odd sources (like MOV) and I saw this crap all the time with it. In fact, such output is exactly what spurred me into learning to do AviSynth as I figured that using HCenc had to be a lot better.

[Bonie81]

jagabo

even at 8800 kbps artifacts are present but very low to visualize,but still there and artifacts are present in only very high motion video. Lower movements/motion part of video bears good quality

[Bonie81]

jman98

i have used TMPGEnc, plus all other leading commercials and free encoder, as one of the local video lab has interest for the results, and they have set-up too! The results of TMPGEnc was not consistent over different video clips. In some produced good quality output and in some clip too much artifacts - hate to watch the output.

As I said HcEnc with AVISynth gave good results.Only need to customize AVISynth script for the different clips (PAL or NTSC).
x264 was also stunning even at 1800kbps.
XViD was OK over 2400 plus kbps too.
rest were real crap coz many failed to encode ac3-448 as is by maintaining same 5.1 or 7.1 channels layout. Even 2000+kbps video bitrate is too low for some encoders and generates visible artifacts.
others need to follow x264 foot-steps to achieve good quality even at lower bit-rate.

[Bonie81]

jagabo

how to reduce the noise in source?
i forgot that part in all sample clips.
i guess, all encoders should have built-in noise reduction automatic algorithm for ease.

[jagabo]

thers need to follow x264 foot-steps

That makes no sense. MPEG 2 encoders, for example, can't follow in x264 foorsteps, they're MPEG 2 encoders not h.264 (MPEG 4 part 10) encoders. They can only encode within MPEG 2 specs or their output won't be playable in MPEG 2 players (DVD players for example). If you want x264 quality at low bitrate use x264. Some other h.264 encoders may be able to deliver comparable quality at those low bitrates but no MPEG 2 encoder or MPEG 4 part 2 (Divx/Xvid) will be able to match it.

how to reduce the noise in source?

Use noise filtering in your editor.

i guess, all encoders should have built-in noise reduction automatic algorithm for ease.

No they should not. The job of a codec is to produce output that looks like the input. If the input has noise the encoder should reproduce it.

[Bonie81]

jagabo

thanks for suggestions.
noise filters works great.
Got v.good quality at lower bitrates too.

Thanks!