Systems and methods for adaptive bitrate streaming of media including subtitles

Abstract

Systems and methods for adaptive bitrate streaming of media including subtitles utilizing Hypertext Transfer Protocol (HTTP) in accordance with embodiments of the invention are disclosed. One embodiment of the invention includes requesting and buffering portions of video from at least one of the alternative streams using a playback device, requesting information indicative of a font utilized by a font-rendering engine to render text from a selected subtitle stream, downloading at least one font file when the font is not present on the playback device, requesting and buffering at least a portion of the selected subtitle stream, decoding the buffered portions of video using a decoder on the playback device, rendering the portions of the subtitle stream corresponding to the buffered portion of video using a font-rendering engine configured by the at least one downloaded font file, and performing synchronized playback of the decoded video and rendered subtitles using the playback device.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application Ser. No. 61 / 430,110, entitled “Systems and Methods For Adaptive Bitrate Streaming of Media Stored in Matroska Files Using Hypertext Transfer Protocol”, filed Jan. 5, 2011, the entirety of which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention generally relates to adaptive streaming and more specifically to adaptive bitrate streaming of encoded media including subtitles using Hypertext Transfer Protocol.BACKGROUND[0003]Presentation of textual information can be an important part of the video viewing experience. Text information may be used to represent the movie title, chapter names, specific track data, as well as subtitles. Subtitles may be used for conveying the dialogue of a video presentation in different languages, to aid those with hearing impairments, poor listening comprehension, or to suit the viewer's current listening preferenc...

AI Technical Summary

Problems solved by technology

However, despite its advantages, because the text information is stored as bitmaps, it adapts poorly to changes in image frame size and as a result cannot be scaled with acceptable visual results to multiple sizes.

In addition to the problem with scalability, bitmap representations are not easily searchable as text, which is an attractive feature from the perspective of categorization, metadata and archival activities.

While the size of these fonts may not be an issue for processing on a personal computer, in an embedded or a consumer electronic device, such large font sizes may pose a problem especially if the fonts are expected to be dynamically available in memory for the device's rendering engine.

When the size of the required representation file exceeds the resource handling capability of an embedded device, the behavior exhibited by these devices and the resulting user-experience may be non-uniform.

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