I presume A264 is another name for H264 right? Or a variation on it.
I googled it and got H.264 listed for first 2 results. H.264/MPEG-4 AVC - Wikipedia, the free encyclopedia
h264 video fastest mepg 4 encoder high-definition DVD

I did see this comment on a forum: "after googling is that x264 is an encoder/encoding library while h264 is a codec"

"X264 is an offshoot of h.264 (which PS3 does support). What you need to do is to lookup MKV2VOB and you will be happy.
This converts the x264 encoded mkv files to H.264 VOB files (retaining 5.1 and HD resolutions). While you are at it, download TVersity and stream these to them to the PS3."

"x264 works just fine. The PS3 is not all that picky with any h264 encoded files. However, the PS3 is irrationally picky with AVC levels -- make sure when you encode with x264 that you use 3.0 (i think), 3.1 (for sure), 4.0, or 4.1. (the mencoder option is "idc_level""

"X264 is an open source h.264 AVC encoder. Just like divx and xvid are h.263 encoders. And it's also considered one of the best out there in a recent comparison for quality and compression."