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Use higher resolution MPEG4s on the iPod Video
Authored by: AaronAdams on Nov 02, '05 07:14:24AM
Handbrake can be used to rip movies from DVD directly to a format that the iPod can use. It requires that you download the Handbrake source, make a change, and compile it.

Handbrake source is available via CVS, and instructions are provided on the app's download page. You'll also need to download something called jam that downloads and compiles other bits and pieces Handbrake needs. Copy the jam executable into the Handbrake folder created when you obtained the CVS source.

Next, find a file in the Handbrake source named libhb/encx264.c and open it in a text editor. Two lines need to be added in the hb_work_object_t * hb_work_encx264_init function. I placed these lines on lines 63 and 64 of the file:

param.b_cabac = 0;
param.i_level_idc = 13;


Save that file and close it. Start Terminal, cd to the Handbrake source folder, and run ./jam. Make sure you're connected to the network when you do that. After some time, a Handbrake executable will be created in the Handbrake source root that can transcode movies directly to iPod-understandable format.

Also, the bitrate in the hint is much too high. There is a rule-of-thumb formula to use to calculate the bitrate:

(width * height * FPS * Q) / 1024

width = pixel width of the picture
height = pixel height of the picture
FPS = source DVD's frames per second
Q = bits per pixel quality for the codec. A good setting for MPEG4 is .23, and a good setting for H.264 is .15. You can change those to suit your tastes.

For a 720 x 304 widescreen movie at 24 FPS, the equation looks like this:

(720 * 304 * 24 * .15) / 1024 = ~770

An average bitrate of 770 kbps will produce a very good looking movie.



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Addendum
Authored by: AaronAdams on Nov 02, '05 07:39:43AM

I forgot to mention something in my previous post. Those directions are intended to create H.264 movies the iPod can display. Handbrake already creates MPEG4 movies that are iPod compatible.



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Use higher resolution MPEG4s on the iPod Video
Authored by: fstop on Nov 02, '05 10:23:18AM

"(width * height * FPS * Q) / 1024

width = pixel width of the picture
height = pixel height of the picture
FPS = source DVD's frames per second
Q = bits per pixel quality for the codec. A good setting for MPEG4 is .23, and a good setting for H.264 is .15. You can change those to suit your tastes.
For a 720 x 304 widescreen movie at 24 FPS, the equation looks like this:

(720 * 304 * 24 * .15) / 1024 = ~770"

I would be very interested in knowing where this equation and constants came from. Aren't DVD-encoded movies about 30 FPS?



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Use higher resolution MPEG4s on the iPod Video
Authored by: lullabud on Nov 02, '05 10:29:27AM
It looks to me like he meant "widescreen film." ;-) FPS is a variable in the original equation, 24 was just filled in for the example.

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Use higher resolution MPEG4s on the iPod Video
Authored by: rpaul on Nov 04, '05 05:53:25AM
I would be very interested in knowing where this equation and constants came from. Aren't DVD-encoded movies about 30 FPS?
Most movies are encoded at 24 FPS as they were shot on film at the that speed. DVD players will do the 30 FPS conversion at playback.

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