Introduction

Welcome to the sixth progress report on Payback for the Gameboy Advance. The earlier reports can be found here. The main focus this month was the video codec that will be used to encode the game's intro.

The Codec

The AMV (Apex Media Video) codec that I've developed is getting compression ratios equal to or better than MPEG1. To give you an idea of how much of an improvement this is over existing GBA codecs, I've encoded Ornaments The Movie using the new codec. First of all, here's an original, uncompressed frame from Ornaments:

Reference image

Now here's that same frame encoded with both AMV and the Mystik Movie Codec:

AMV	Mystik Movie

	Resolution	Compression ratio*
Reference image	240x160	N/A
AMV	240x160	125:1
Mystik Movie	120x80	20:1

As you can see, AMV gives similar quality to Mystik Movie at a higher resolution with a dramatically higher compression ratio. Note that the current version of AMV has rather bad colour reproduction and no sound, but these are both things that can be fixed in the future. There is also still some scope for improving the compression ratio and supporting higher quality settings.

Incidentally, the game's 72 second long intro (a screenshot of which is shown on the right) compresses to just 900K. This is a compression ratio of 225:1, which is better than any other codec I tried, and not just on the GBA.

Next month

The focus over the next month will be on fixing bugs, getting night levels working properly, adding save game support and (hopefully) getting a publisher. If you'd like to see Payback in the shops then let your favourite publisher know.

Please feel free to email us with any questions, suggestions or enquiries. We do not yet have a publisher for the GBA version of Payback - please email us at queries@apex-designs.net if you're interested in publishing the game. For general information about Payback, please click here.

* The compression ratio is calculated relative to an uncompressed size of width*height*frames*3 bytes. A slight fudge factor in Mystik Movie's favour was added to account for the fact that it encodes the sound whereas AMV currently does not.