Distinguishing requests for presentation time from requests for data time
Techniques are provided for managing Presentation Time in a digital rendering system for presentation of temporally-ordered data when the digital rendering system includes a Variable Rate Presentation capability. In one embodiment, Presentation Time is converted to Data Time, and Data Time is reported instead of Presentation Time when only one time can be reported. In another embodiment, a predetermined one of Presentation Time and Data Time is returned in response to a request for a Current Time.
1. A method, performed by at least one computer processor executing computer program instructions stored on at least one non-transitory computer-readable medium, the method for use in conjunction with a rendering system which renders temporal sequence presentation data, the method comprising steps of:
(A) receiving a request from the rendering system for a current time of the temporal sequence presentation data during rendering of the temporal sequence presentation data by the rendering system;
(B) in response to the request, performing steps of:
(1) calculating a data time parameter value representing an amount of time required to render the temporal sequence presentation data at a default presentation rate; and
(2) returning the data time parameter value to the rendering system in response to the request.
2. The method of claim 1 , wherein the step (B) comprises steps of:
(B) (1) (a) identifying a number of elements in the temporal sequence presentation data;
(B) (1) (b) identifying a rendition period required to render one of the elements in the temporal sequence presentation data; and
(B) (1) (c) multiplying the number of elements by the identified rendition period to identify the value of the data time parameter.
3. The method of claim 1 , wherein the step (B) comprises steps of:
(B) (1) (a) for each element in the temporal sequence presentation data:
(i) identifying a default rendition period of the element;
(ii) adding the default rendition period to a data time parameter value; and
(B) (2) pr viding returning the sum produced by step (B) (1) (a) as the data time parameter value.
4. The method of claim 1 , wherein the step (B) comprises steps of:
(B) (1)(a) for each element in the temporal sequence presentation data:
(i) identifying an actual rendition period of the element;
(ii) identifying an actual presentation rate of the element;
(iii) multiplying the actual rendition period of the element by the actual presentation rate of the element;
(iv) adding the product of step (B) (1) (iii) to a data time parameter value; and
(B) (2) returning the sum produced by step (B) (1) (a) as the data time parameter value.
5. The method of claim 1 , wherein the step (B) comprises a step of identifying, as the value of the data time parameter, a time integral of a presentation rate of the temporal sequence presentation data over the amount of time elapsed during rendering of the temporal sequence presentation data, wherein the presentation rate is equal to the ratio of a change in the value of the data time parameter over time to a change in the value of the presentation time parameter over time.
6. A system for use in conjunction with a rendering system which renders temporal sequence presentation data, the system comprising at least one non-transitory computer-readable medium, the at least one non-transitory computer-readable medium comprising computer program instructions executable by at least one computer processor to perform a method, the method comprising steps of:
(A) receiving a request from the rendering system for a current time of the temporal sequence presentation data during rendering of the temporal sequence presentation data by the rendering system;
(B) in response to the request, performing steps of:
(1) calculating a data time parameter value representing an amount of time required to render the temporal sequence presentation data at a default presentation rate; and
(2) returning the data time parameter value to the rendering system in response to the request.
7. A method performed by at least one computer processor executing computer program instructions stored on at least one non-transitory computer-readable medium, the method for use in conjunction with a rendering system which renders temporal sequence presentation data, the method comprising steps of:
(A) receiving a request from the rendering system for a current time of the temporal sequence presentation data during rendering of the temporal sequence presentation data by the rendering system;
(B) determining, based on a property of the request, whether to return a value of a data time parameter or a value of a presentation time parameter; and
(C) returning to the rendering system, in response to the request, the value determined in step (B).
8. The method of claim 7 , wherein the property comprises an property of an executing computer program which submitted the request.
9. The method of claim 7 , wherein the property comprises a property of a computer platform on which the method is executing.
10. The method of claim 7 , wherein the property comprises a value accessible to the method during step (B).
11. A system for use in conjunction with a rendering system which renders temporal sequence presentation data, the system comprising at least one non-transitory computer-readable medium, the at least one non-transitory computer-readable medium comprising computer program instructions executable by at least one computer processor to perform a method, the method comprising steps of:
(A) receiving a request from the rendering system for a current time of the temporal sequence presentation data during rendering of the temporal sequence presentation data by the rendering system;
(B) determining, based on a property of the request, whether to return a value of a data time parameter or a value of a presentation time parameter; and
(C) returning to the rendering system, in response to the request, the value determined by the means for determining.