PSMF videos can be up to 480x272 pixels in size, which is the true 16:9 native resolution of the Sony PSP. Videos in this format can be as small as 64x64 pixels and are played back at a framerate of 29.97 fps. The PSMF uses a macroblock size of 16x16 pixels and the file format is based on the MPEG-2 program stream. The header of the PSMF dictates multiplexing.
The video codec used by the PSMF is known as H.264 (aka MPEG-4 Part 10 AVC). The audio codec primarily used is the Sony proprietary ATRAC3+.
PSP Video 9