Clip that plays fine in WMP is cut off in Sony Vegas
This isn't a Vegas issue. The recording application has registered the video resolution as 1024x768 in the MP4 global header (../stsd/avc1) but the full 1080p stream is captured and stored.

Vegas is using the header metadata to crop the video stream at the stage of loading the file. So, any Vegas functions/plugins downstream to this stage don't, know of, or have access to the full image data.

However, the full resolution is correctly stored in the metadata (SPS) of the video stream itself. So remuxing the file with ffmpeg will resolve the issue as ffmpeg constructs a new global header, based on reading the stream metadata.

ffmpeg -i recorded.mp4 -c copy fixed.mp4


Get a FFmpeg Windows binary from https://ffmpeg.zeranoe.com/builds/