Method for backing up digital cinematographic content

Abstract

The present invention relates to a method for backing up digital cinematographic content, comprising the steps of: generating, from said content, a digital stream encoded in a compressed format, or having said digital stream already encoded in a compressed format; and recording said digital stream encoded in a compressed format onto a photographic film.

Claims

1. A method for backing up digital cinematographic content including a stream of digital images and all the digital data relating to the stream of digital images, the method comprising: generating a digital stream from the digital cinematographic content, the digital stream encoded in a compressed JPEG 2000 format, or having the digital stream already encoded in the compressed JPEG 2000 format, and recording the encoded digital stream onto a photographic film in a redundant manner and in the compressed JPEG 2000 format onto the photographic film, the redundancy of the digital data recorded on different sections of the same photographic film such that damaging more than one centimeter of the photographic film does not preclude restoration of all the data of the digital cinematographic content to be backed up.

2. The method as claimed in claim 1, the photographic film being an analog 35 mm film.

3. The method as claimed in claim 1, further comprising: reading of data recorded onto the film; and comparing the read data with the data to be recorded.

4. The method as claimed in claim 1, wherein the film is imaged and developed in line.

5. The method as claimed in claim 1, wherein the imaged data is encoded by gray levels of pixels onto the photographic film.

6. The method as claimed in claim 1, further comprising: allowing a user to issue a request for the recovery of digital data backed up on the photographic film by way of a user interface, reading the photographic film and regenerating the digital data in a compressed format, and transmitting the digital data to the user.

7. The method as claimed in claim 1, further comprising: upon detecting a data error in the digital stream recorded on the photographic film, recording a corrective onto the photographic film.

Description

(1) The present invention will be better understood upon reading the following detailed description, of a non-limiting exemplary embodiment of the latter, and upon examining the appended drawing, wherein:

(2) FIG. 1 is a block diagram illustrating various steps of a method for archiving digital data according to the invention,

(3) FIG. 2 illustrates the steps of a method for recovering digital data archived according to the invention.

(4) The archiving method according to the invention, some steps of which are illustrated in FIG. 1, comprises the fact of having source digital cinematographic data in a step 10. It is a 4K version, for example.

(5) The method can include a step 20 of encoding these data in a compressed format, notably the JPEG 2000 format, as encountered in the DCP. In a variant, the data to be archived are supplied in an already compressed format.

(6) The file format for the container of the images and audio is the MXF. There is one MXF container for containing the images, another for the audio. There can be other containers of MXF files, for example as many as there are audio tracks. The back-ups of metadata, sound, and images can be carried out at respectively separate places on the photographic film.

(7) The compressed digital data are imaged in the next step 30 on an analog 35 mm film. The data are preferably encoded in the form of pixels encoding an item of information by their gray level, with one pixel encoding over 2.sup.8 gray levels, for example. An algorithm allows the digital data that are to be backed up to pass to the pixels to be imaged, in such a way as to allow the subsequent reproduction of the digital data.

(8) For example, a scan is performed on the film as it scrolls, and each pixel is imaged with a gray level that encodes a binary information item. The reading is carried out with the same scan, in order to successively read the pixels and determine their gray level, which makes it possible to regenerate the digital information.

(9) The film is developed in line in the step 40 and a reading can be carried out just after development, in line, in the step 50 to ensure the reliability of the save.

(10) An inspection system makes it possible to check that the read imaged data do indeed match the source data. This system can include an in-line scanner at the output of the processor.

(11) In the event of a recording error being detected, during the inspection, data marred with errors can be rerecorded onto the film in the step 60, and inspected again. Data signaling the presence of the corrective on the film can be recorded on the latter.

(12) The photographic film is then stored by a storage device, for example in an air-conditioned warehouse.

(13) FIG. 2 shows the steps of recovery of the source digital data. In the step 70, a request for recovery of data is carried out on an interface. Next, the film is recovered and read by a scanner, in the step 80, to regenerate the data encoded in the previous step 20. Where applicable, a new encoding in a different format is performed in the step 85.

(14) The digital data are then transferred to a digital medium or over a network to the user having requested them, in the step 90.

(15) The expression including a must be understood as being synonymous with including at least one, unless the contrary is specified.