You Can Now Enable HD Video Recording on iPhone 3GS ! [Jailbreak Req.]

Here is a way to get the phone to record video (and playback on the iPhone) at 1080×800 @ 30fps at up to 20Mbps. (up from the original 640×480 @ 3Mbps) (I am using the non-standard 1080×800 in order to keep the video at the right aspect ratio)

For the truly impatient: download the pre-edited file HDVideo3GS.zip.
Jailbreak your device and install SSH
Copy N88AP.plist to /System/Library/CoreServices/SpringBoard.app/
Copy the 3 other plist files to /System/Library/PrivateFrameworks/Celestial.framework/N88/
Reboot your iPhone 3GS

One quick look at the ARM Cortex processor that the 3GS uses [PDF Spec], it’s apparent that the chip is capable of handling 720p video encoding. So all we need to do is by-pass the artificial limitation Apple has imposed on the hardware.

Here is how:
I am assuming your iOS device is running firmware 4.1, I have not tested this with older versions of iOS
Jailbreak your 3G/3GS with limerain or greenpoison. Install OpenSSH via Cydia.
SSH into your phone using the root account
Open /System/Library/PrivateFrameworks/Celestial.framework/N88/AVCapture.plist with a Plist editor
Under the AVCaptureMode_AudioVideoRecording key, set the width and height for the capture key to 1080×800, respectively. This value controls the dimension of the video it is encoded at.
Set the width and height for the preview key to 440×320. This value controls the size of the on-screen preview. It does not have any effect on the final video.
Set the width and height for the sensor key to 1920×1080. This value controls the active region of the sensor, so basically, we want to use the entire sensor. This source will be automatically downscaled to the proper resolution at encoding time.
Increase the encoding average bitrate to 20Mbps (20000000bps), this records a much larger video file (~ 2MB for every second of video)
Increase the encoding bitrate cap to 40Mbps. Also, lower the minimum quantizer from 19 to 15 or something, just for the heck of it.
Set the H264 profile from 3_0 to 3_1 (because wikipedia says so)
Save and close this file.
To make the phone playback the recorded HD video. Simply edit CameraRollValidator.plist and MediaValidator.plist, they can be found in the same place as AVCapture.plist. (If you don’t do this, the file can only be played back on your computer)
Replace 768 with 1280
And replace
MaxLevel
30

with
MaxLevel
31
Save these two files.
Open /System/Library/CoreServices/SpringBoard.app/N88AP.plist with a Plist editor, and add the following under the capability node, this will enable HD recording from the camera app:
720p

hd-video-capture

If you are having a hard time figuring out where to make the changes, download the pre-edited file HDVideo3GS.zip Then simply copy the plist files to the correct location via SCP.
Reboot your iDevice.


Results:
 

Posted in: Apple, How-to, iPhone 3G, Jailbreak