Try the original AVCHD media first
Current VEGAS Pro releases can open many MTS and M2TS recordings directly. Import from the complete AVCHD camera folder when it is available because playlist, audio, and spanned-clip metadata may be stored outside the individual video files.
Test a representative clip before converting anything. If import succeeds and timeline playback is responsive, keep the original media in the project.
Convert only when the source is unreliable
Create an editing copy when a recording mode is unsupported, the camera structure is incomplete, audio is missing, or long-GOP decoding makes the timeline unstable. Match the project resolution, frame rate, scan type, and audio layout rather than choosing a preset from the filename alone.
Spanned recordings should be joined through the camera structure or a verified media workflow so clip boundaries do not introduce missing frames or audio gaps.
Verify the editing copy
Check picture, motion, audio, sync, and clip duration in VEGAS Pro before processing the remaining media. Keep the original camera folders until the project and every converted clip have been verified.


