Client, a content creator entity and methods thereof for media streaming
The embodiments of the present invention relate to methods and arrangements for accomplishing trick modes. This is achieved by assigning samples within a track to sample groups, wherein all samples within a sample group belong to one temporal level and by allowing the client to access one temporal level independently of lower temporal levels. In this way, the flexibility for the client regarding play out of different frame rates is increased which can result in a lower bandwidth utilization.
1. A method in a content creator computing device for enabling trick modes of a system of files, the files comprising at least one initialization segment and at least one media segment, wherein the at least one media segment comprises at least one track having a plurality of media samples and the at least one initialization segment comprises descriptions of the at least one media segment, the method comprising:
identifying media samples within one track having identical temporal levels;
grouping the media samples into sample groups such that all media samples in a sample group have identical temporal levels;
marking the sample groups with temporal level information indicating the temporal level of the media samples of the respective sample group in the at least one initialization segment;
adding information to the at least one initialization segment that indicates at least one sample group that has a temporal level greater than zero that can be decoded independently without using samples having lower temporal levels; and
transmitting the at least one initialization segment to a client computing device to enable selective download and trick modes for the sample groups.
2. The method of claim 1 , wherein the temporal level information is associated with a sample grouping type.
3. The method of claim 2 , wherein the temporal level information is a sample group description index.
4. The method of claim 3 , wherein the sample group description index comprises a rate_factor parameter which is a positive integer indicative of an increased time progression that is achievable for a given sample group having a given temporal level by playing all samples having the given temporal level and samples having lower temporal levels at an original sample rate.
5. The method of claim 3 , wherein the sample group description index comprises a data_offset parameter that is an integer pointing to a start of a first sample relative to a start of a media segment with the temporal level of the sample.
6. The method of claim 1 , wherein the added information is included in a sample group description.
7. The method of claim 1 , wherein a predefined parameter in a Segment Type box (STYP) of the media segment is used to signal that samples of the media segment are grouped such that samples of a lower temporal level precede those of a higher temporal level.
8. A content creator entity for enabling trick modes of a system of files, the files comprising at least one initialization segment and at least one media segment, wherein the at least one media segment comprises at least one track having a plurality of media samples and the at least one initialization segment comprises descriptions of the at least one media segment, the content creator entity comprising:
a processor configured to:
identify media samples within one track having identical temporal levels;
group the media samples into sample groups such that all media samples in a sample group have identical temporal levels;
mark the sample groups with temporal level information indicating the temporal level of the samples of the respective sample group in the at least one initialization segment; and
add information to the at least one initialization segment that indicates at least one sample group that has a temporal level greater than zero that can be decoded independently without using samples having lower temporal levels; and
transmit the at least one initialization segment to a client computing device to enable selective download and trick modes for the sample groups.
9. The content creator entity of claim 8 , wherein the temporal level information is associated with a sample grouping type.
10. The content creator entity of claim 9 , wherein the temporal level information is a sample group description index.
11. The content creator entity of claim 10 , wherein the sample group description index comprises a rate_factor parameter which is a positive integer indicative of an increased time progression that is achievable for a given sample group having a given temporal level by playing all samples having the given temporal level and samples having lower temporal levels at an original sample rate.
12. The content creator entity of claim 10 , wherein the sample group description index comprises a data_offset parameter that is an integer pointing to a start of a first sample relative to a start of a media segment with the temporal level of the sample.
13. The content creator entity of claim 8 , wherein the added information is included in a sample group description.
14. The content creator entity of claim 8 , wherein a predefined parameter in a Segment Type box (STYP) of the media segment is used to signal that samples of the media segment are grouped such that samples of a lower temporal level precede those of a higher temporal level.