Not DV - Locked audio and unlocked audio

[infoeater]

Is unlocked audio used only by consumer DV camcorders? Is it used by consumer AVCHD camcorders, mobile phones, video DSLR, etc?

Is unlocked audio allowed in AVI, MP4, MKV, OGM, MTS file containers?

[Ghitulescu]

It's also in Digital8.
AVCHD and other new containers, are containers, and the synch between Audio and Video is kept using time stamps. For tape based systems like DV, the audio was separately processed and stored.

[infoeater]

As far as I know unlocked audio is used only because it's cheaper to use two independent systems to record audio and video, then two synced systems and I don't see connection between this and tape as a medium.

Is there in new containers with constant audio and video sampling rate only locked audio?

As Digital8 cameras have unlocked audio, what happen, then there are recording video to it's SD card slot as MPEG files, as some of them can do so?

[Ghitulescu]

The tape on which the DV information resides is recorded in tracks, there are 10 or 12 tracks per each frame in PAL/NTSC (that is why you can have "half images" on older camcorders, because they overwrite parts of those 10 or 12 tracks). It is no difficulty in keeping the signals in synch over firewire, or to record them, or to play them. The difficulty appears on editing "on tape" those videos. Here the pro solutions could solve the issue of audio cut (for hard cuts), but the consumer range was, for cost reasons, left outside. For computer editing, this poses almost no issue.

Tapeless formats do comprise EVERYTHING in one container, and the synch is provided by timestamps (which are not required to be temporally equally spaced, but this rarely happens).

[infoeater]

THX for reply with description. Now I understand.

http://www.adamwilt.com/DV-FAQ-tech.html <This link maybe usable for other people looking for information about locked and unlocked audio in DV format.