Notices

Transcoding is lossy, so if they play fine unpacked, you're better off not transcoding.

(This assumes you're keeping the original -- if you discard the original, transcoding to h.264 to save disk space could be a reasonable tradeoff...)

Ok yes, fair enough. As I understand it, not every codec combination is going to be well supported in the DSP, so I should have defined "optimal" really. What I want is smooth playback without errors with minimal cpu use - ie taking the best advantage of the hardware acceleration.

So I would accept some loss through transcoding if it meant lower impact on battery life for example. I read that if the content is over 800x480, then the DSP isn't used, so if I had to scale that down, I would still want to select the best combination.