Anime Myths

[Ranguvar]

Alright... I've heard lots of myths about anime encoding. The don't-use-cartoon-mode one seems debunked, but what about trellis? I can only find 1 or 2 talks about this, and those are years old.

Also I-frames... I heard it's good to increase the number of frames per forced I-frame to 500.

And B-VOP sensitivity, I heard it was good to lower the sensitivity.


I will try testing myself, but if anyone knows anything, please post. Thanks.

[Dark Shikari]

No reason not to use Trellis.

Raising I-frame interval is good, yes.

I haven't heard anything about B-frame sensitivity though.

One non-myth about anime: H.264 is vastly more efficient than Xvid, due to CABAC and the ability to use multiple reference frames.

[TheRyuu]

Another thing about anime that I'm not sure is true or not, is adaptive quant. I've heard that it can cause ringing, not sure about this, but I keep it disabled for that AND the fact that it blocks dark areas more (which for anime, I think is BAD).

[Dark Shikari]

Another thing about anime that I'm not sure is true or not, is adaptive quant. I've heard that it can cause ringing, not sure about this, but I keep it disabled for that AND the fact that it blocks dark areas more (which for anime, I think is BAD).The problem with AQ in anime is twofold:

1. People often encode anime at very low bitrates. This means that encoding the QP_deltas for adaptive quantization actually costs a non-negligible amount of bits.

2. While some anime has gradients and other such issues that AQ is useful for, other anime hardly has any, so AQ just results in wasted bits, since there are no fine details or gradients to be kept.

Its mainly something you want to "try and see" for. Some people have reported great success with VAQ on anime, others have reported failure.

[Chainmax]

What if you encode anime at fairly high bitrates like ~1500kbps for a 640x480 resolution (taking into account very high motion content)?

[Dark Shikari]

What if you encode anime at fairly high bitrates like ~1500kbps for a 640x480 resolution (taking into account very high motion content)?Try and see :p

Depends on the anime, of course. For your average anime clip, 1500kbps is plenty, but there are definitely individual segments that basically require 1500kbps to avoid artifacting. Example: the Haruhi "Hare Hare Yukai" dance scene.

[TheRyuu]

The problem with AQ in anime is twofold:

1. People often encode anime at very low bitrates. This means that encoding the QP_deltas for adaptive quantization actually costs a non-negligible amount of bits.

2. While some anime has gradients and other such issues that AQ is useful for, other anime hardly has any, so AQ just results in wasted bits, since there are no fine details or gradients to be kept.

Its mainly something you want to "try and see" for. Some people have reported great success with VAQ on anime, others have reported failure.

I was talking about xvid's AQ.
If it was x264, I'd definitely use AQ. (VAQ).

[Dark Shikari]

I was talking about xvid's AQ.
If it was x264, I'd definitely use AQ. (VAQ).Not sure about Xvid's AQ. Advantage: It uses far fewer bits, due to Xvid's linear quantizer. Disadvantage: I'm not sure how useful Xvid's AQ is overall.

[Ranguvar]

Sorry I didn't do the tests yet. My 278GB NTFS partition on my 300GB HDD crashed and burned. -_- I can recover the data, but it'll take a bit.

Can't WAIT until AviSynth 3, and all-Linux for me....

[Chainmax]

Try and see :p

Depends on the anime, of course. For your average anime clip, 1500kbps is plenty, but there are definitely individual segments that basically require 1500kbps to avoid artifacting. Example: the Haruhi "Hare Hare Yukai" dance scene.

Artifacts being typical x264 ones (blurring and blocking?)?
Also, would AQ affect the compatibility of x264's profiles?

[Dark Shikari]

Artifacts being typical x264 ones (blurring and blocking?)?
Also, would AQ affect the compatibility of x264's profiles?AQ does not affect compatibility.

In anime, artifacts generall consist of ringing and loss of detail (and of course blocking in dark/flat areas).