AVCHD video playback hardware puzzle
I just upgraded my graphics card from a Geforce 8400 GS to a GT 520 1 GB, because my Ubuntu 10.04 system wasn't able to play back 1080 50p footage from my new Panasonic camcorder - video playback was extremely choppy from the original MTS video files. But to my dismay, the new card doesn't to the job, either. Now I am clueless. My system isn't that bad: a Q6600 quad core overclocked to 3 Ghz, 6 GB RAM.
I had tried it on my WinXP dual boot with the latest drivers and playback was equally choppy, so I figured the issue must be the graphics card. But now I'm not so sure any more. Moreover, the amazing thing is that the new laptop of my wife, featuring a i3-370 dual core (2.4 Ghz) with some integrated Intel graphics, CAN play it fluently, without any stuttering at all!!! Now, that is amazing. In both cases VLC player was used, on her system with Windows 7, I run 64 bit Ubuntu with the latest NVIDIA graphics driver (270.41.19). Note: 17mbps 50i playback is no problem at all. I can also play the transcoded to mp4 version of the MTS videos without problem, even when the mp4 video's bitrate is up to 150 Mbit (transcoding AVCHD with FFMPEG using the -sameq setting you can get crazy bitrates).
Now, I am lost as to what to do. Is it the CPU, or the graphics card, or what ???! I'm sure the issue is that of decoding the highly compressed AVCHD, but which bit of my computer is most responsible for that? BTW, my CPU is only being utilised around 80-100% (of 400 % of all four cores) during the very choppy MTS video playback.