Sanyo XACTI VPC-GH3GX - Manual (Page 160)

151
English
About audio files recorded with this camera
i If you change the extension (.m4a) of audio files to “.mp4”, playback may
be possible using software that supports the ISO standard MPEG-4 (AAC
audio).
About file names when the card is replaced...
i If the file number continued function is set to on, even when the card is
replaced, consecutive numbering of folder numbers and file names
continues from the previously installed card (page 135).