Even in a world of clever solutions to difficult technical challenges, this is pretty cool...a classic example of making the best out of what you have to work with.
This is a photo of a section of a 35mm movie print, the kind shown in most theaters. Because this format has been around for a long time, long before the advent of modern movie soundtracks, one of the big technical challenges faced by the new crop of competing audio formats was where to cram all that multitrack digital information on the physical filmstrip.
Well, as you can see, compromises were made and turf battles were fought, but in the end every player got a chunk of real estate to solve the problem in their own unique way. This 35mm "Quad Track" print contains all four of the current movie sound formats (SDDS, Dolby Digital, Optical, DTS) so a given theater can show the movie on whatever sound system it has in-house and the studio doesn't have to print different versions of the film.
Here's the breakdown:
1) The blue area at left, outside the sprocket holes, is the Sony Dynamic Digital Sound (SDDS) track. Well, half of it, the other half exists on the other side of the filmstrip. This is a 2D array that is a pictorial representation of a digital data stream. It decodes back into an 8-channel soundtrack in real-time when played. The first SDDS movie was The Last Action Hero in 1993.
2) In between the sprocket holes (talk about a challenge) resides the Dolby Digital track. You can see the DD logo in the center. This is a series of 2D arrays with breaks for the holes. A CCD reads these arrays and creates from them an unbroken AC-3 bitstream which produces a 6-channel soundtrack. Batman Returns in 1992 was the first Dolby Digital movie. The format was expanded in 1999 to add a matrixed rear surround channel just in time for Star Wars Episode I: The Phantom Menace.
3) To the right of the sprocket holes is the analog optical soundtrack. This is the oldest of these technologies and has been around since the earliest days of sound movies. The width required by this soundtrack is what defined the shape of the Academy Standard aspect ratio of 1.37:1 for the picture, before the age of widescreen. Originally this was mono, but was split into stereo tracks later. With the advent of Dolby Stereo this two-track area could be specially encoded and then "dematrixed" when played back, expanding it into a 4-channel soundtrack. This was and early implementation of modern surround sound.
4) That dashed line to the right is the Digital Theater Systems (DTS) 24-bit Time Code. With the DTS system the actual soundtrack is encoded on optical disc in a separate device called the DTS processor, the time code on the film is needed to synchronize the film with the external soundtrack to ensure accurate timing. The separate optical disc contains a 6-channel soundtrack. An advantage of this system is that the DTS soundtrack is not subject to damage from the projector as are the other formats. But on the down side, it's more complicated as it requires an extra processor and disc. The first DTS movie was Jurassic Park in 1993.
Of these sound formats, both DTS and Dolby Digital are supported on DVD and Blu-ray, with Blu also supporting the newer 24-bit lossless 8-channel formats DTS HR Master Audio and Dolby TrueHD among others. Unlike in the theater though, they are stored very differently.
The imagination and tenacity of the human brain never ceases to amaze me. Even incredible technical solutions like this are almost commonplace in our world.
This is a photo of a section of a 35mm movie print, the kind shown in most theaters. Because this format has been around for a long time, long before the advent of modern movie soundtracks, one of the big technical challenges faced by the new crop of competing audio formats was where to cram all that multitrack digital information on the physical filmstrip.
Well, as you can see, compromises were made and turf battles were fought, but in the end every player got a chunk of real estate to solve the problem in their own unique way. This 35mm "Quad Track" print contains all four of the current movie sound formats (SDDS, Dolby Digital, Optical, DTS) so a given theater can show the movie on whatever sound system it has in-house and the studio doesn't have to print different versions of the film.
Here's the breakdown:
1) The blue area at left, outside the sprocket holes, is the Sony Dynamic Digital Sound (SDDS) track. Well, half of it, the other half exists on the other side of the filmstrip. This is a 2D array that is a pictorial representation of a digital data stream. It decodes back into an 8-channel soundtrack in real-time when played. The first SDDS movie was The Last Action Hero in 1993.
2) In between the sprocket holes (talk about a challenge) resides the Dolby Digital track. You can see the DD logo in the center. This is a series of 2D arrays with breaks for the holes. A CCD reads these arrays and creates from them an unbroken AC-3 bitstream which produces a 6-channel soundtrack. Batman Returns in 1992 was the first Dolby Digital movie. The format was expanded in 1999 to add a matrixed rear surround channel just in time for Star Wars Episode I: The Phantom Menace.
3) To the right of the sprocket holes is the analog optical soundtrack. This is the oldest of these technologies and has been around since the earliest days of sound movies. The width required by this soundtrack is what defined the shape of the Academy Standard aspect ratio of 1.37:1 for the picture, before the age of widescreen. Originally this was mono, but was split into stereo tracks later. With the advent of Dolby Stereo this two-track area could be specially encoded and then "dematrixed" when played back, expanding it into a 4-channel soundtrack. This was and early implementation of modern surround sound.
4) That dashed line to the right is the Digital Theater Systems (DTS) 24-bit Time Code. With the DTS system the actual soundtrack is encoded on optical disc in a separate device called the DTS processor, the time code on the film is needed to synchronize the film with the external soundtrack to ensure accurate timing. The separate optical disc contains a 6-channel soundtrack. An advantage of this system is that the DTS soundtrack is not subject to damage from the projector as are the other formats. But on the down side, it's more complicated as it requires an extra processor and disc. The first DTS movie was Jurassic Park in 1993.
Of these sound formats, both DTS and Dolby Digital are supported on DVD and Blu-ray, with Blu also supporting the newer 24-bit lossless 8-channel formats DTS HR Master Audio and Dolby TrueHD among others. Unlike in the theater though, they are stored very differently.
The imagination and tenacity of the human brain never ceases to amaze me. Even incredible technical solutions like this are almost commonplace in our world.
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