Is this the right place to ask this?
I recently bought a Panasonic HDC-TM300 video camera. (Yes, it's lovely.) Played with it shooting stuff on the street etc. Imported them to my computer and they played fine using an ordinary viewer. Now my computer doesn't recognise these same files. Shot some more, all imported via an SD card. Can't get the computer to play them nor the ones already imported THAT DID PLAY when I first took them across.
It seems that they are M2TS files.
However. Adobe Premiere Elements 7 does accept them, but plays them haltingly, seeming to jump several frames along as it bumbles through. Very puzzled that files that did run, now don't. They all play perfectly well when reviewed within the camera itself.
I know very little about the ins and outs of video file formats. Nor about AVCHD and other recording modes. I do know a bit about making TV programmes, but only as a BBC Producer (now retired) who always had technical people around to manage the hardware and press the right buttons. (And, it should be said, to make very valuable creative contributions to the programmes we made.)
Any thoughts, anyone?
The files from your camcorder are 1920x1080 resolution compressed using MPEG4 h.264 format. That compression is very efficient at making the files smaller and still reproducing a beautiful picture. The problem is that to decompress it is very processor intensive. Dedicated players can play it back fairly well, but for an editor to decompress it into memory for editing and display it for preview is a bit much to ask of most hardware. That is why at one point your player ran fine, but dropping it into PE yields choppy playback. I am not sure what happend to screw up your player. PE is doing its best and it is really expecting too much of it to play it back well unless you are on a powerhouse workstation.
Development is in progress at some manufacturers to improve the ability for editors to play it back. Some manufacturers are pursuing methods of transcoding it to intermediate formats for edit.
For the time being, take the raw files and transcode it to a high bit rate alternate file such as HDV before editing it.