Software Decoding and Hardware Decoding

[[ss]vegeta]

Hello
When I use software decoder to play a video, seeking is FAST but rotating a video is SLOW (sluggish).
When I use hardware decoder to play a video, seeking is SLOW (sluggish) but rotating a video is FAST (smooth).
I have an old PC, with an AMD Phenom 2 at 3.4ghz and a Radeon 5770 1GB ddr5.

SW uses processor to decode video, HW uses GPU, right?
Why for the GPU rotating is fast but seeking is slow?
Why for the CPU rotating is hard but seeking is fast?

[redwudz]

Probably rotation is function of your hardware video card. Not sure if I can answer your whole question.
Seeking depends on your video. H264 for example, has few i frames, with lots of space between them.
That can affect your seeking.

Processing is essentially number processing. Sometimes GPU is faster, sometimes CPU is faster.
Depends on the video, the GPU, and the CPU. Sorry, probably not much help.

Others members may give better advice, but it looks like more information is needed.