Content-based unique material identifiers
A unique material identifier (UMID) for a media file that was not provided with a UMID at its point of origination is generated by using the content of the file, and is independent of the time of file import or accessing. For a given item of media material, the UMID remains unchanged and uniquely identifies the item when such a file is imported or accessed multiple times. The UMID may be generated by hashing together selected portions of the metadata and essence of the media file. The amount of metadata and essence sampled is chosen to provide a high degree of assurance that the UMID will be unique, but is kept small enough so as to avoid causing a perceptible lag when the UMID is generated. In various embodiments the UMID is based purely on one or more selected portions of the media file essence.
1. A method of distinguishing a first digital media file from a second digital media file, the method comprising:
at a first client hosting a first media processing software application, receiving a link to a first digital media file that is not associated with a unique material identifier (UMID);
using the first media processing application:
accessing the first digital media file;
selecting a first quantity of data from a plurality of non-contiguous portions of media essence of the first digital media file; and
generating a first UMID for the first digital media file directly from the first quantity of data, wherein selecting the first quantity of data balances requirements that a size of the first quantity of data is:
small enough to enable the first media processing application to generate the first UMID in a time that is not perceptible to a user of the first media processing software application when accessing the first digital media file; and
large enough to ensure an acceptable likelihood that the first UMID uniquely identifies the first digital media file;
at a second client hosting a second media processing software application, receiving a link to a second digital media file that is not associated with a UMID;
using the second media processing application:
accessing the second digital media file;
selecting a second quantity of data from a plurality of non-contiguous portions of media essence of the second digital media file; and
generating a second UMID for the first second digital media file directly from the second quantity of data, wherein selecting the second quantity of data balances requirements that a size of the second quantity of data is:
small enough to enable the second media processing application to generate the second UMID in a time that is not perceptible to a user of the second media processing software application when accessing the second digital media file; and
large enough to ensure an acceptable likelihood that the second UMID uniquely identifies the second digital media file;
wherein each of the non-contiguous portions of the first digital media file and of the second digital media file are derived from different sets of one or more frames of media essence of the respective digital media files, and wherein the first and second UMIDs are independent of times when the first and second digital media files were received, such that the first UMID is different from the second UMID when at least one of:
the first digital media file features a first media content in a first format and the second digital media file features the first media content in a second format that is different from the first format; and
the first digital media file features a first shot of a first subject and the second digital media file features a second shot of the first subject, and the first shot is different from the second shot; and
associating the first and second UMIDs with their respective digital media files by at least one of:
creating a pointer from the first and second UMIDs to their respective digital media files; and
writing the first and second UMIDs into a metadata field of their respective digital media files.
2. The method of claim 1 , wherein the first TIMID is further based on one or more metadata fields associated with the first file.
3. The method of claim 2 , wherein the one or more metadata fields include a track information field.
4. The method of claim 2 , further comprising selecting the metadata associated with the first file based on a likelihood that the metadata distinguishes the first file from other digital media files.
5. The method of claim 1 , further comprising selecting the plurality of non-contiguous portions of the media essence of the first file based on a likelihood that the media essence distinguishes the first file from other digital media files.
6. The method of claim 1 , wherein one of the selected portions of media essence comprises media essence corresponding to temporal locations in the first file of between 5 and 20 seconds from the beginning of the first file.
7. The method of claim 6 , wherein one of the selected portions of media essence further comprises media essence corresponding to temporal locations in the first file of between 5 and 20 seconds before the end of the first file.
8. The method of claim 1 , wherein one of the selected portions of media essence comprises an amount of data in the range of 0.5 to 2 megabytes of data starting from a location near the beginning of the essence.
9. The method of claim 1 , wherein one of the selected portions of media essence comprises an amount of data in the range of 0.5 to 2 megabytes starting from a location near the middle of the essence.
10. The method of claim 1 , wherein generating the first UMID comprises using a hash function to generate the first UMID from the selected plurality of portions of media essence of the first file, wherein the first UMID comprises a string of a predetermined length.
11. The method of claim 10 , wherein the predetermined length is one of 16 bytes and 32 bytes.
12. The method of claim 1 , wherein a delay associated with generating the first UMID is less than about 100 milliseconds.
13. The method of claim 1 , further comprising:
receiving links to a plurality of digital media files in addition to the first and second digital media files;
for each digital media file of the plurality files:
generating a UMID for the digital media file, wherein the UMID distinguishes between different versions of the digital media file, wherein the UMID is directly generated from a selected plurality of non-contiguous portions of media essence of the file, and wherein the UMID is independent of a time of receiving the digital media file; and
associating the UMID with the digital media file; and
wherein a delay associated with performing the generating and associating steps for the plurality of digital media files and for the first-mentioned file is less than about 100 milliseconds.
14. The method of claim 1 , wherein the standard portion of the first digital media file at the beginning of the digital media file comprise color bars.
15. The method of claim 1 , wherein the standard portion of the first digital media file at the beginning of the digital media file comprise black frames.
16. A computer program product comprising:
a non-transitory computer-readable medium with computer program instructions encoded thereon, wherein the computer program instructions, when processed by a computer, instruct the computer to perform a method of distinguishing a first digital media file from a second digital media file, the method comprising:
at a first client hosting a first media processing software application, receiving a link to a first digital media file that is not associated with a unique material identifier (UMID);
using the first media processing application:
accessing the first digital media file;
selecting a first quantity of data from a plurality of non-contiguous portions of media essence of the first digital media file; and
generating a first UMID for the first digital media file directly from the first quantity of data, wherein selecting the first quantity of data balances requirements that a size of the first quantity of data is:
small enough to enable the first media processing application to generate the first UMID in a time that is not perceptible to a user of the first media processing software application when accessing the first digital media file; and
large enough to ensure an acceptable likelihood that the first UMID uniquely identifies the first digital media file;
at a second client hosting a second media processing software application, receiving a link to a second digital media file that is not associated with a UMID;
using the second media processing application:
accessing the second digital media file;
selecting a second quantity of data from a plurality of non-contiguous portions of media essence of the second digital media file; and
generating a second UMID for the first second digital media file directly from the second quantity of data, wherein selecting the second quantity of data balances requirements that a size of the second quantity of data is:
small enough to enable the second media processing application to generate the second UMID in a time that is not perceptible to a user of the second media processing software application when accessing the second digital media file; and
large enough to ensure an acceptable likelihood that the second UMID uniquely identifies the second digital media file;
wherein each of the non-contiguous portions of the first digital media file and of the second digital media file are derived from different sets of one or more frames of media essence of the respective digital media files, and wherein the first and second UMIDs are independent of times when the first and second digital media files were received, such that the first UMID is different from the second UMID when at least one of:
the first digital media file features a first media content in a first format and the second digital media file features the first media content in a second format that is different from the first format; and
the first digital media file features a first shot of a first subject and the second digital media file features a second shot of the first subject, and the first shot is different from the second shot; and
associating the first and second UMIDs with their respective digital media files by at least one of:
creating a pointer from the first and second UMIDs to their respective digital media files; and
writing the first and second UMIDs into a metadata field of their respective digital media files.
17. The method of claim 1 , wherein the first client is the same as the second client.
18. The method of claim 1 , wherein the first media processing software application is the same as the second media processing software application.
19. The method of claim 1 , wherein the first media processing application is a video editing application.