Old Apple TV Preset vs. New Apple TV Preset

[darkpixie08]

Can someone explain to me the difference between the old apple tv preset and the new one. It seems to me that because the old apple tv preset had a high bitrate (2500 was it?) and the new preset has just a constant quality of 59% that the old ATV preset would result in better video quality. Can someone please explain this to me?

I used to just use the AppleTV preset with 2-pass encoding, turbo first pass, and that seemed to result in great video. I am wondering if something has changed in handbrake that I don't need such a high bit-rate anymore. (Admittedly, I've never understood the real difference between how bitrate vs. constant quality affect things).

Any explanation on the difference between the old ATV preset and the new ATV preset, and how/why they affect the video would be greatly appreciated. Thanks!

[gmacman]

Well, this is a bit of a pontification for me, but...

The new preset will give you a much better file for ATV. I've been quietly running their snapshots while waiting for 0.9.3 to become real and I've seen much better quality, much smaller files (read as: better streaming), well just much better all the way around.

I believe the reason is the newer x264 as well as stuff like psy rdo and psy trellis, psy rdo is something called "Psychovisually optimized Rate-Distortion Optimization". Yea, I know...WHAT? doom9.org is where I usually go to learn about this stuff and even then it's way over my head. Handbrake's own wiki gives a good explanation of this stuff too.

However I have noticed that the ATV Preset has actually changed slightly from the Snapshot 3 that I was using and it no longer uses Subpixel Motion Estimation setting of 9 and instead only uses 7. And I am curious why the drop there. I suspect we get all the benefit of rdo/trellis at 7. Although now I'm confusing myself because it also shows cabac=0 and I think I remember reading that psy-trellis (which does some picture quality stuff I think) requires cabac (this is , I believe, an algorithm that reduces the size of the file).

Okay, so I really am pontificating. Just read the handbrake wiki and google some of the options that are on the "Advanced" tab in the ATV preset for a much better definition that my six year-old brain can give you.

[dynaflash]

However I have noticed that the ATV Preset has actually changed slightly from the Snapshot 3 that I was using and it no longer uses Subpixel Motion Estimation setting of 9 and instead only uses 7. And I am curious why the drop there.

Increased speed at minimal quality loss.

I suspect we get all the benefit of rdo/trellis at 7.

psy-rdo yes, but psy-trellis still has to be specified in the opts to be enabled, and is still somewhat experimental in x264 as mentioned by its author Dark_Shikari, so we leave it out of the presets purposely.

[gmacman]

Thanks dynaflash

I knew I was over my head in answering this.

Can you shed some light on the subme change in the preset from 7 to 9? What I mean is, the change down to 7 is for...?

Thanks in advance,

Steve

[dynaflash]

um, increased encoding speed with minimal quality loss ... <confused>

[gmacman]

um, increased encoding speed with minimal quality loss ... <confused>

Good enough. As mentioned, most of the advanced settings are above my head, so I exclusively encode with whatever you all decide on for the presets. I was just curious if there was something specific that was found during testing that made the decision to drop down to 7.

Having only an iMac and MacBook the increased encoding speed sounds like a great reason to me.

[sharvey]

Is it just me, or has anyone else noticed a substantial slow down in encoding rates using the latest Apple TV preset? With the old preset i am getting betwen 25-30fps, but with the new one I am having a hard time reaching 15fps. What might I change to speed things up a little?

[nightstrm]

You could use the legacy AppleTV preset... its the same as .9.2.

You shouldn't be surprised by this... it's discussed in the release announcment.

[MonkeyBites]

Just like the original poster, I used the AppleTV preset in Handbrake 0.92 (with 2 passes/turbo first pass enabled). Now I encoded The Two Towers (LOTR) with the new AppleTV preset in 0.93, and again with the same preset and the quality level raised to 65%.

In both cases, the new preset's output is a little brighter, but less smooth than the old one's output (even though the bitrate comes out higher in the case of the 65% variant).

From everything I've read about x264 in 0.93, and the new presets, I would have expected a better quality than what I achieved with 0.92. Am I missing something?

[jbrjake]

In both cases, the new preset's output is a little brighter, but less smooth than the old one's output (even though the bitrate comes out higher in the case of the 65% variant).

"Less smooth"? What does this even *mean*?

And saying "output is a little brighter" without mentioning what video player you use is pointless.

[MonkeyBites]

"Less smooth"? What does this even *mean*?

And saying "output is a little brighter" without mentioning what video player you use is pointless.

Sorry: By "smoother" I mean that most surfaces (i.e. human skin) look more natural (they exhibit less pixelation) in the 0.92/ABR with 2 passed variant. I compared the output using QuickTime Player on a MacBook Pro.

[jbrjake]

Sorry: By "smoother" I mean that most surfaces (i.e. human skin) look more natural (they exhibit less pixelation) in the 0.92/ABR with 2 passed variant.

And are you comparing still frames or motion video? Because still frame comparisons are pointless.

I compared the output using QuickTime Player on a MacBook Pro.

...per the 0.9.3 change set, QuickTime color display has been changed by signaling the proper color matrix.

[MonkeyBites]

Sorry: By "smoother" I mean that most surfaces (i.e. human skin) look more natural (they exhibit less pixelation) in the 0.92/ABR with 2 passed variant.

And are you comparing still frames or motion video? Because still frame comparisons are pointless.

I compated short scenes following the first frame of several chapters (although only for a single movie). In all cases, I had the impression that the 2-pass ABR video was slightly better than the quality-based video.

[Aragorn II]

Could someone comment on the Picture Settings of the New vs. Legacy presets? I'm curious about the fact that the dimensions under the New preset are smaller than those under the Legacy. It may be that there's no difference once you enter Full Screen mode, but it's odd when comparing the two against the original DVD, all at actual size, that the New preset version is smaller than the others.

As far as I can tell, the difference is that the New uses "loose" rather than "strict" anamorphic, and the Legacy also had a "custom" crop set to 0, 0, 0, 0.

Is the New just the same quality in a smaller package?

[jbrjake]

Legacy also had a "custom" crop set to 0, 0, 0, 0.

Um, no. It didn't.

[Aragorn II]

Legacy also had a "custom" crop set to 0, 0, 0, 0.

Um, no. It didn't.

I open HB, select "AppleTV Legacy", click "Picture Settings", and observe that the Crop setting is "Custom" and that all the input fields below have a "0" in them. That is what my statement is referring to.

[jbrjake]

Sorry. Legacy was re-added at the list minute due to user complaints, and apparently its key structure is interpreted differently now. It's the same code as before, but now it's defaulting to a custom crop because it never had a key to signal autocrop.

[Aragorn II]

After a bit of experimentation it seems that the width doesn't vary much, and the main difference seems to be on the height due to the black bars being eliminated across the top and the bottom.