Merge pull request #1901 from oioitff/audio-fix2

Use another method to scale by envelopValue.
Merge pull request #1898 from oioitff/audio-fix

Implement pcm voice correctly
Add files for support mpeg and atrac3plus.
Prepare for video.
Add media files cache.
Implement sceAtrac with dshow
Implement scePsmf
Implement sceMpeg