Laserdisc analog tracks. How are played?

[ofbarea]

Does any body know how it’s encoded and played the analog track of the laserdisc?

[flaninacupboard]

most players have an "audio" button, press it and it switches between analogue and digital.

it's "encoded" as a series of pits and lands, just like a cd. the length of the pits determines the video frequency, and the length of the lands determines the audio frequency (could be the other way round on that one! ). There's some good info out there if you google.

[ofbarea]

NTSC laser disc movies usually have a couple of digital tracks and a couple of analog tracks, only very old movies have analog only audio (this is not true for PAL laserdiscs). Some newer laserdisc movies have an AC3 track, taking the place of right analog track.

I know that the digital tracks are encoded using plain 44.1 PCM. If present, AC3 track is a 5 channel Dolby digital stream.

But so far I have not found any documentation on how the analog (not the digital or AC3) audio is encoded or read.

[flaninacupboard]

as i said, the analogue track is determined by the length of a pit or land.
see this page: http://www.laserdiscarchive.co.uk/laserdisc_archive/how_laserdiscs_are_produced.htm

it's an FM signal, so like a radio station with very good reception.

[ofbarea]

Thanks a lot for the link. I though audio and video were written in a different fashion.

By any chance do you know why some people say that the digital audio channel is better that the analog channel?

In theory the Analog signal should be better that the digital one. right?

[flaninacupboard]

well, analogue audio is bandwidth dependant. you know that MW radio is inferior to FM radio, which is inferior to casette tape, which is inferior to vinyl, which is inferior to 2" magnetic tape used in a recording studio.

it's like directly comparing CD and FM radio, or comparing an analogue TV boradcast of a film to DVD playback of the same film.