RV10 max or optimal bits/pixel

[ToiletDuck]

When I do xivd rips sometimes I use gknot because I like how it tells me what the maximum bits/pixel the codec can handle. What is the maximum or optimum bits/pixel to have?
Duck

[Sirber]

Encode Q100 and see :) There is no MAX (IMO).

[Latexxx]

You propably mean minimum pits/pixel ratio.

[ToiletDuck]

no no i mean maximum. Like when using gknot and xvid it shows you after you load the d2v file and change the ratio the amount of bits per pixel and it has a set number at like .226 or something like that is the maximum of the codecs efficiency.

[Asmodian]

I don't think that number really had anything to do with the codec's efficiency does it? That is just the number of bits you specified over the total number of pixels (bits/pixel) and the min or max reasonable number there depends largely on the source and what degree of compression you want as well as the video codec. That said I usually use something between 0.12 and 0.18 when doing rv10 encodes. I like very high quality encodes (with in-loop filtering off I usually needs somewhat >0.18 b/p to be free of artifacts but it is very sharp/detailed) so others may recommend trying even lower b/pix values. I compress anime/cartoon in real not live action. Live action will probably look too smooth at these b/pix and Xvid is better (IMHO) anyway.

[damrod]

agree!!

rmvb for anime
xvid pour live video...except if you want to encode long time in short size (3h in 700Mo for exemple)

[LiFe]

RV8 used to have a quality index, which is now somewhat different than with RV9/10 but here are the docs anyway:

A value of 94 to 100 means that the clip will play back with excellent quality. You could even increase the video frame rate or window size and achieve high quality.

A value of 60 to 93 represents the efficiency range of the RealVideo 8 codec. Streams with these values will have good visual clarity and a high frame rate. Above 80 will have good visual quality.

A value of 40 to 59 indicates fair quality. These stream may have some visual artifacts and slow frame rates in some if not all sections. You'll achieve higher quality by shrinking the source video's window size.

A value from 0 to 40 indicates poor quality playback with a slow frame rate and a high number of artifacts. You should shrink the video's window size if you intend to stream at this speed.

With RV9 I find that a vlue of 60 - 69 represents excelent quality for the bits spent (compared to other codecs). When quality gets above 72 I find that there are more bits being spent than noticable quality improvements. Below 60 and the video starts to degrade, slowly, then quickly.

My measurements are with large frame sizes. Bit spend is obviously much more conservative at much smaller frame sizes.

LiFe.

[Asmodian]

@LiFe
How does one get an idea what these numbers are for a particular encode? Where do they come from, do they have anything to do with bits/pixel?

[karl_lillevold]

I think those quotes are from a rather old Producer documentation trying to give some advice re fixed Quality encodes. They are not related to bits/pixel. The Quality setting is really nothing but a reverse mapping from 10-100 to the codec's quantizer range 0-30. If you are really curious, you can use rv9log.txt to see which Quality maps to which quantizer.

[LiFe]

Quality is still valid with VBR or CBR encodes. Just pop up the stats and you can moniter what Q the encoder is achieving. If it's sitting on 90-100 you could probably increase the frame size or frame rate or reduce the bitrate and see little to no change.

If it's at 0 - 30, you will notice that the vid is pretty unwatchable!

LiFe.