How to achieve 16:9 (640 x 360) encoding w/ GREAT results!

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fullerflyer
Posts: 58
Joined: Mon Feb 12, 2007 5:52 am

How to achieve 16:9 (640 x 360) encoding w/ GREAT results!

Post by fullerflyer »

I just wanted to share that I've been achieving some outstanding results with the latest build of HB and I have done some experimenting, varying up the aspect settings a bit, resulting in a true 16:9 (640 x 360) aspect ratio.

Despite the numerous warnings to never try encoding with anything other than mod16 multiples, I'm getting some STELLAR encodes with a 640 x 360 setting (mod8), preserving the true 16:9 resolution!

I've read as much as I can find on the reasons not to do this, but I have to say I'm exceptionally pleased with the finished product once the video is encoded. I'm achieving stellar results with the utilization of the latest "Advanced" settings tab, optimizing the maximum settings (to my knowledge) for iPod compatible video. While it does take significanly longer (3 times longer, at that) to encode with these settings, the end result is worth it for me.

My Settings Are As Follows:

Video:

Encoder: x264 (h.264 iPod)
2-pass Encoding
Average bitrate (kpbs): 1500kpbs
--------------------
Audio:

Sample rate: 48
Bitrate: 160
--------------------
Advanced:

Reference Frames: 2
Mixed-References: Yes
Motion Estimation Method: Uneven Multi-Hexagon
Motion Estimation Range: 64
Subpixel Motion Estimation: 7

(all other advanced settings remain at "Default")

(If I'm missing something/misunderstanding iPod's capabilities, someone please correct me, but I believe that all of the above settings will allow for successful iPod playability.)

All of this, coupled with a 640 x 360 Aspect Ratio is producing some GREAT files.

I am unable to detect any inferior quality with the 640 x 360 compared to the mod16 640 x 352 or 6400 x 368.

After careful scrutinization comparing the same video clip(s) encoded at 640 x 352/368 and the 16:9, 640 x 360, I can tell no difference in quality. I have no "colored-bars" across the picture or any other problems that I'm aware of (granted I've not involved any scientific processes other observation with my own two eyes).

-------- How to Adjust HB's Vertical Aspect Setting To 360 --------

Initially, I couldn't figure out how to get HB to encode with a height of 360, but after playing with the settings I was able to figure out how to do it.

To achieve a 640 x 360 setting, follow the tutorial steps below:

1. go to "Picture Settings" under the main Video tab and de-select "Keep Aspect Ratio."

2. Select the "Custom" crop option.

3. Adjust the upper vertical setting to an abnormal value, such as "88" (You may need to experiment with this value per the given DVD to fine tune it, but so far, the first two 16:9 DVD's I've encoded have required that I adjust the upper vertical setting to "88" - keep reading to understand what I mean*.)

4. Next, select "Anamorphic (PAR). At this point the picture will stretch to anamorphic while keeping the cropped vertical setting ("88") from the previous step. You'll notice that the "Height:" setting multiples have now changed... Rather than it being the standard multiple of 16, counting up from 0 (i.e... 352, 368, 384, 400), notice now that the multiples have shifted. What you are going for is for it to shift by a value of 8 (in order to shift from 352 to 360/368 to 360). So whereas the height once went from 352 to 368 to 384... Now you are able to adjust to values such as 360, 376, 392, etc...

5. De-select "Anamorphic (PAR)"

6. Re-adjust your vertical crop setting back to "0" (or whatever value you are aiming for (Note: The "Height" setting will/should remain at 360).

*Referencing Step 3:

...If the vertical setting of "88" does not produce the multiple you are hoping for, simply begin step 3 again with an alternate Vertical setting...

-------------------------------------------------------------------------------------

I hope this is helpful, and that someone else is willing to give the 16:9 a go... I apologize if I am offending anyone by suggesting that encoding in other than mod16 format is acceptable, equal to, or superior to mod16, but my experiences have proven fruitful thus far.

To any mods: If this post in any way is frowned upon, please feel free to remove it.

Thanks, and happy encoding!:lol:

rhester
Veteran User
Posts: 2888
Joined: Tue Apr 18, 2006 10:24 pm

Re: How to achieve 16:9 (640 x 360) encoding w/ GREAT result

Post by rhester »

fullerflyer wrote:To any mods: If this post in any way is frowned upon, please feel free to remove it.
Not at all - this is good information and detailed research on your part.

The mod16 recommendation is exactly that - the exact impact of going mod8 is difficult to ascertain because it depends on so many variables. In the end, your eyes are the best judge - if you are happy with the results, that's what counts!

Rodney

loyalty_anchored
Bright Spark User
Posts: 183
Joined: Wed Mar 14, 2007 1:49 pm

Post by loyalty_anchored »

im gonna have to give this a try when i get home :-)

EDIT: wait a second, are you saying you will always use 640 x 360 regardless of the original aspect ratio? will you not be distorting the picture, even if the distortion is minimal, is this acceptable?

fullerflyer
Posts: 58
Joined: Mon Feb 12, 2007 5:52 am

Post by fullerflyer »

loyalty_anchored wrote:EDIT: wait a second, are you saying you will always use 640 x 360 regardless of the original aspect ratio? will you not be distorting the picture, even if the distortion is minimal, is this acceptable?
Certanly not. I was only trying to find a way to preserve 16:9 Aspect Ratio for movies that are such in their original format.

Until now, most everywhere I'd read it was saying that you had to stick to mod16 and therefore you could not preserve 16:9 (640 x 360), as 360 is not a multiple of 16, but a multiple of 8. So when I found out that it was possible to do this, and seemingly without any quality loss or other problems, I just wanted to share it with the rest of you.

Peace

deckeda
Regular User
Posts: 138
Joined: Thu Feb 22, 2007 8:38 am

Post by deckeda »

loyalty_anchored wrote: ... will you not be distorting the picture ...
Perhaps all of his sources are 1.78:1, so it's an ideal match.

Or perhaps he doesn't care if the image is skewed --- and there are legions of HDTV owners for example who would rather have that than black bars under any circumstances.

deckeda
Regular User
Posts: 138
Joined: Thu Feb 22, 2007 8:38 am

Post by deckeda »

fullerflyer wrote: Certanly not. I was only trying to find a way to preserve 16:9 Aspect Ratio for movies that are such in their original format.
I appreciate your work here; you've put a lot of effort into this. But I'm curious about your movie list. The only one I've come across so far that's natively 1.78:1 (a 16:9 ratio) is Finding Nemo, which of course wasn't created on film originally. But the far, far more common 1.85:1 is I suppose pretty close.

fullerflyer
Posts: 58
Joined: Mon Feb 12, 2007 5:52 am

Post by fullerflyer »

deckeda wrote:
fullerflyer wrote: Certanly not. I was only trying to find a way to preserve 16:9 Aspect Ratio for movies that are such in their original format.
I appreciate your work here; you've put a lot of effort into this. But I'm curious about your movie list. The only one I've come across so far that's natively 1.78:1 (a 16:9 ratio) is Finding Nemo, which of course wasn't created on film originally. But the far, far more common 1.85:1 is I suppose pretty close.
I'm encoding concert videos at the moment... U2, primarily:

Rattle And Hum
Vertigo 2005//Live From Chicago
Vertigo 2005//Live From Milan
U2 go Home//Live From Slane Castle...

Those are all 16:9

handbreakuser25
Posts: 9
Joined: Thu May 31, 2007 3:04 am

By the way...

Post by handbreakuser25 »

Do u use CRF or the default setting?
Jesus it does take a lot slower than the usual in my ibook G4 1.33 768 ram is only doing 3.6 frames per second so... its gonna be 2 days before i see the results.
Question: Does the way that it is cropped matter? 88 happened to be to high so I ended up using something smaller but with 640 x 360 will this affect the picture?
Im passing Forest gump which originally cropped to around 640 x 304. If i remember correctly looking forward to the results. :)!

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