Method, device, and computer program for encapsulating region annotations in media tracks
The present invention concerns a method of generating a media file, the method comprising: generating a first track of media data samples; generating a region track associated with the first track, each sample of the region track comprising a region description data structure comprising geometry information of one or more regions in at least one corresponding sample of the first track; wherein the region description data structure comprises a region identifier associated with each region; and the method further comprise: generating a region annotation in a container; generating association metadata associating a region identifier with the region annotation; generating a media file including the first track, the region track, the region annotation, and the association metadata.
1 . A method of generating a media file, the method comprising:
generating a first track of media samples;
generating a second track associated with the first track and comprising at least one sample, each sample of the second track comprising a region definition data structure;
generating a region annotation in a container; and
generating a media file including the first track, the second track, and the container comprising the region annotation;
wherein:
the region definition data structure comprises a region geometry information and a region identifier for each of one or more regions in at least one sample of the first track;
the second track further comprises an association data structure providing a mapping between a region identifier and the region annotation, the association data structure comprising the region identifier and associated information for identifying the region annotation; and
the information for identifying the region annotation comprises an annotation container type for identifying the type of container comprising the region annotation.
2 . The method of claim 1 , wherein the association data structure is comprised in a data structure describing a group of samples of the second track.
3 . The method of claim 1 , wherein the information for identifying the region annotation further comprises:
an annotation reference type identifying a code type of the container comprising the region annotation; and
an index for identifying the container carrying the region annotation.
4 . The method of claim 3 , wherein the annotation container type is one value among at least the following values:
a first value indicating that the container comprising the region annotation is a sample of a track or an item identified by the annotation reference type and the index; or
a second value indicating that the container comprising the region annotation is an entry in a data structure describing a group of samples identified by the annotation reference type and the index.
5 . The method of claim 1 , wherein the container of the region annotation is an entry of a sample group description data structure in the second track.
6 . The method of claim 1 , wherein the container of the region annotation is a sample of a dedicated track associated with the second track.
7 . The method of claim 1 , wherein the container of the region annotation is an item associated with the second track.
8 . The method of claim 1 , wherein at least two region annotations are provided into two different containers.
9 . The method of claim 1 , wherein the container of the region annotation is an item property in an item property container.
10 . The method of claim 1 , wherein the container of the region annotation is a track associated with the second track.
11 . The method of claim 1 , wherein:
metadata describing the second track comprises an indication for indicating that a set of at least some of the region identifiers used in the second track are persistent over a set of at least some of the second track samples.
12 . The method of claim 11 , wherein the indication is provided in an entry of a sample description box describing second track samples, the set of second track samples being the second track samples described by the entry of the sample description box.
13 . The method of claim 1 , wherein the association data structure associates one or more sample groups in the second track with one or more region identifiers and further associates the one or more region identifiers with one or more containers each of which comprises a region annotation.
14 . The method of claim 1 , wherein the second track comprises a first box defining one or more sample groups in the second track and a second box including the association data structure associating the one or more sample groups defined in the first box with one or more region identifiers.
15 . The method of claim 14 , wherein in a case where the first box defines a plurality of sample groups, the second box includes the association data structure associating each of the plurality of sample groups with each of corresponding region identifiers.
16 . The method of claim 14 , wherein the media file is compliant with ISOBMFF, and the first box is a SampleToGroupBox and the second box is a SampleGroupDescriptionBox.
17 . A method for processing a media file, the method comprising:
obtaining a first track of media data samples from the media file;
obtaining, from the media file, a second track associated with the first track and comprising at least one sample, each sample of the second track comprising a region definition data structure;
obtaining, from the media file, a region annotation in a container; and
processing one or more regions in at least one media sample of the first track based on an association data structure and the region annotation;
wherein:
the region definition data structure comprises a region geometry information and a region identifier for each of one or more regions in at least one sample of the first track;
the second track further comprises the association data structure providing a mapping between a region identifier and the region annotation, the association data structure comprising the region identifier and associated information for identifying the region annotation; and
the information for identifying the region annotation comprises an annotation container type for identifying the type of container comprising the region annotation.
18 . A non-transitory computer-readable storage medium storing instructions of a computer program for implementing a method according to claim 1 .
19 . A device for generating a media file, the device comprising a processor configured for:
generating a first track of media samples;
generating a second track associated with the first track and comprising at least one sample, each sample of the second track comprising a region definition data structure;
generating a region annotation in a container; and
generating a media file including the first track, the second track, and the container comprising the region annotation;
wherein:
the region definition data structure comprises a region geometry information and a region identifier for each of one or more regions in at least one sample of the first track:
the second track further comprises an association data structure providing a mapping between a region identifier and the region annotation, the association data structure comprising the region identifier and associated information for identifying the region annotation; and
the information for identifying the region annotation comprises an annotation container type for identifying the type of container comprising the region annotation.
20 . A device for processing a media file, the device comprising a processor configured for:
obtaining a first track of media samples from the media file;
obtaining, from the media file, a second track associated with the first track and comprising at least one sample, each sample of the second track comprising a region definition data structure;
obtaining, from the media file, a region annotation in a container; and
processing one or more regions in at least one media sample of the first track based on an association data structure and the region annotation;
wherein:
the region definition data structure comprises a region geometry information and a region identifier for each of one or more regions in at least one sample of the first track:
the second track further comprises the association data structure providing a mapping between a region identifier and the region annotation, the association data structure comprising the region identifier and associated information for identifying the region annotation; and
the information for identifying the region annotation comprises an annotation container type for identifying the type of container comprising the region annotation.