P
Phil Allison
- Jan 1, 1970
- 0
Hi to all,
ever wondered how Dolby Digital 5.1 sound is ACTUALLY carried by a 35mm
cinema film ?
Turns out the 320 kbit/s DD data stream is encoded onto squares optical
grids of about 60 x 60 bits & very cunningly fitted in * between* the
sprocket holes !!
http://upload.wikimedia.org/wikipedia/commons/1/1d/35mm_film_audio_macro.jpg
The embedded Dolby logo is cute dontcha think ?
A tiny CCD camera in the projector captures each 2.4mm square image, 96 of
them per second, so it can be processed into 5 channels of audio.
The other tracks you see are Sony SDDS, L/R stereo analogue and timing
pulses for DTS so the CD can be synched with the movie.
Such a multi-format movie can be shown by any cinema in the world and exact
copies are made by ordinary, chemical film processing.
Betcha you ALL knew that already ....
........ Phil
ever wondered how Dolby Digital 5.1 sound is ACTUALLY carried by a 35mm
cinema film ?
Turns out the 320 kbit/s DD data stream is encoded onto squares optical
grids of about 60 x 60 bits & very cunningly fitted in * between* the
sprocket holes !!
http://upload.wikimedia.org/wikipedia/commons/1/1d/35mm_film_audio_macro.jpg
The embedded Dolby logo is cute dontcha think ?
A tiny CCD camera in the projector captures each 2.4mm square image, 96 of
them per second, so it can be processed into 5 channels of audio.
The other tracks you see are Sony SDDS, L/R stereo analogue and timing
pulses for DTS so the CD can be synched with the movie.
Such a multi-format movie can be shown by any cinema in the world and exact
copies are made by ordinary, chemical film processing.
Betcha you ALL knew that already ....
........ Phil