Controlling speed of the display of sub-titles

Patent metadata

Field	Value
Publication number	US-2017311045-A1
Application number	US-201515510412-A
Country	US
Kind code	A1
Filing date	Sep 11, 2015
Priority date	Sep 17, 2014
Publication date	Oct 26, 2017
Grant date	—

Abstract

Applying a presentation timestamp to an element of a sequence of sub-titles. A minimum presentation timestamp T MIN of an element of a sequence of sub-titles N is initialized. The presentation timestamp T(N) of the new element of a sub-title sequence N is compared with the minimum presentation timestamp for sub-titles T MIN . The minimum presentation timestamp for sub-titles T MIN is applied to the element of a sequence of sub-titles N if the presentation timestamp T(N) of the new sub-titles element is prior to the minimum presentation timestamp for sub-titles T MIN . The minimum presentation timestamp for sub-titles T MIN for an element of a sequence of sub-titles N+1 is calculated as a timestamp posterior to the presentation timestamp T(N) of the new sub-titles element.

First claim

What is claimed is:

1 . One or more non-transitory computer-readable storage mediums storing one or more sequences of instructions for applying a presentation timestamp to an element of a sequence of sub-titles, wherein execution of the one or more sequences of instructions by one or more processors causes:
initializing a minimum presentation timestamp T MIN of an element of a sequence of sub-titles N; comparing the presentation timestamp T(N) of the new element of a sub-title sequence N and the minimum presentation timestamp for sub-titles T MIN ; applying the minimum presentation timestamp for sub-titles T MIN to the element of a sequence of sub-titles N if the presentation timestamp T(N) of the new sub-titles element is prior to the minimum presentation timestamp for sub-titles T MIN ; and calculating the minimum presentation timestamp for sub-titles T MIN for an element of a sequence of sub-titles N+1 as a timestamp posterior to the presentation timestamp T(N) of the new sub-titles element.

2 . The one or more non-transitory computer-readable storage mediums of claim 1 , wherein the minimum presentation timestamp for sub-titles T MIN is recalculated by adding a duration T MD to the presentation timestamp T(N).

3 . The one or more non-transitory computer-readable storage mediums of claim 2 , wherein the duration T MD retains a fixed value.

4 . The one or more non-transitory computer-readable storage mediums of claim 2 , wherein the duration T MD is dependent on the size of the sub-titles element N.

5 . The one or more non-transitory computer-readable storage mediums of claim 4 , wherein the duration T MD is dependent on the number of words of the sub-titles element N.

6 . The one or more non-transitory computer-readable storage mediums of claim 4 , wherein the duration T MD is dependent on the number of characters of the sub-titles element N.

7 . The one or more non-transitory computer-readable storage mediums of claim 1 , wherein executing the one or more sequences of instructions further cause:
forming the element of a sequence of sub-titles N by grouping several words into a block.

8 . The one or more non-transitory computer-readable storage mediums of claim 7 , wherein the block contains a sentence.

9 . The one or more non-transitory computer-readable storage mediums of claim 7 , wherein the block contains a line of words.

10 . The one or more non-transitory computer-readable storage mediums of claim 1 , wherein the presentation timestamp is written in a multimedia stream.

11 . The one or more non-transitory computer-readable storage mediums of claim 11 , wherein the multimedia stream is an MPEG-TS stream.

12 . The one or more non-transitory computer-readable storage mediums of claim 10 , wherein the multimedia stream includes a sub-titles stream according to one of the TTML norms of the W3C.

13 . The one or more non-transitory computer-readable storage mediums of claim 1 , wherein the presentation timestamp of the sub-titles element is provided to a video decoder for display.

14 . An apparatus for applying a presentation timestamp to an element of a sequence of sub-titles, comprising:
one or more processors; and one or more non-transitory computer-readable storage mediums storing one or more sequences of instructions, which when executed, cause:
initializing a minimum presentation timestamp T MIN of an element of a sequence of sub-titles N;
comparing the presentation timestamp T(N) of the new element of a sub-title sequence N and the minimum presentation timestamp for sub-titles T MIN ;
applying the minimum presentation timestamp for sub-titles T MIN to the element of a sequence of sub-titles N if the presentation timestamp T(N) of the new sub-titles element is prior to the minimum presentation timestamp for sub-titles T MIN ; and
calculating the minimum presentation timestamp for sub-titles T MIN for an element of a sequence of sub-titles N+1 as a timestamp posterior to the presentation timestamp T(N) of the new sub-titles element.

15 . The apparatus of claim 14 , wherein the minimum presentation timestamp for sub-titles T MIN is recalculated by adding a duration T MD to the presentation timestamp T(N).

16 . The one or more non-transitory computer-readable storage mediums of claim 15 , wherein the duration T MD retains a fixed value.

17 . The apparatus of claim 15 , wherein the duration T MD is dependent on the size of the sub-titles element N.

18 . The one or more non-transitory computer-readable storage mediums of claim 17 , wherein the duration T MD is dependent on the number of words of the sub-titles element N.

19 . The one or more non-transitory computer-readable storage mediums of claim 17 , wherein the duration T MD is dependent on the number of characters of the sub-titles element N.

20 . The apparatus of claim 14 , wherein executing the one or more sequences of instructions further cause:
forming the element of a sequence of sub-titles N by grouping several words into a block.

21 . The apparatus of claim 20 , wherein the block contains a line of words or a sentence.

22 . The apparatus of claim 14 , wherein the presentation timestamp is written in a multimedia stream.

23 . The apparatus of claim 22 , wherein the multimedia stream is an MPEG-TS stream.

24 . A method of applying a presentation timestamp to an element of a sequence of sub-titles, comprising:
an encoder, transcoder, or decoder, executing upon hardware comprising one or more processors, initializing a minimum presentation timestamp T MIN of an element of a sequence of sub-titles N; the encoder, transcoder, or decoder comparing the presentation timestamp T(N) of the new element of a sub-title sequence N and the minimum presentation timestamp for sub-titles T MIN ; the encoder, transcoder, or decoder applying the minimum presentation timestamp for sub-titles T MIN to the element of a sequence of sub-titles N if the presentation timestamp T(N) of the new sub-titles element is prior to the minimum presentation timestamp for sub-titles T MIN ; and the encoder, transcoder, or decoder calculating the minimum presentation timestamp for sub-titles T MIN for an element of a sequence of sub-titles N+1 as a timestamp posterior to the presentation timestamp T(N) of the new sub-titles element.

Assignees

• Harmonic Inc

Inventors

• Besnard Xavier
• Jouan Michel

Classifications

• H04N21/4884 Primary

  for displaying subtitles · CPC title

• H04N21/8547

  involving timestamps for synchronizing content · CPC title

• H04N2005/44526

  Electricity · mapped topic

• H04N5/44508

  Electricity · mapped topic

• H04N5/44513

  Electricity · mapped topic