Font Data Streaming

Abstract

Provided is a method for font data streaming for time-based video/audio presentations where content is transmitted in small increments and transmission continues while a previously transmitted portion is viewed or played. Different subsets of characters of the same font are assembled together on a device and previously sent characters are reused for rendering subsequent text strings. Font subsets are created to provide only a minimal number of glyphs for the character set coverage, thereby reducing the redundancy of font data transmission and reducing the total number of characters transmitted.

What is claimed is: 
     
         1 . A method of font data streaming in relation to font data transmissions, the method comprising steps as follows:
 subdividing a media stream into data segments, the media stream including character data and font data;   analyzing text content of a data segment to determine any required fonts and an initial character set coverage for that data segment;   for each required font, generating and storing into memory a font subset that comprises only glyphs necessary for the initial character set coverage; and   transmitting the font subset along with the respective data segment to a receiving device;   wherein said steps reduce redundancy in font data transmissions through reducing total number of characters for data transmitted during any given transmission to said receiving device.   
     
     
         2 . The method of  claim 1 , wherein each data segment represents a unit of data or a collection of multiple different units of data including video, audio, subtitles, and fonts. 
     
     
         3 . The method of  claim 1 , further comprising:
 analyzing text content of a subsequent data segment to determine required fonts and character set coverage for the subsequent data segment;   for each required font, generating a current font subset that comprises only glyphs necessary for the character set coverage for the subsequent data segment;   comparing the current font subset with any previous font subset and removing from the current font subset those glyphs that have been sent in a previous font subset, to produce a reduced font subset;   storing the reduced font subset into memory; and   transmitting the reduced font subset along with the subsequent data segment to a receiving device.   
     
     
         4 . The method of  claim 3 , further comprising:
 storing the previous font subset at the receiving device; and   updating the font subset stored at the receiving device by adding the reduced font subset to the stored previous font subset.   
     
     
         5 . The method of  claim 1 , wherein the data stream is transmitted to a plurality of receiving devices that receive the data stream at different times and each device views a complete transmission regardless of a viewing start time by the device. 
     
     
         6 . The method of  claim 5 , wherein the font subset and the respective data segment are transmitted and stored at a first device and subsequently transmitted and stored at other devices. 
     
     
         7 . The method of  claim 3 , wherein the font subsets are stored at a server. 
     
     
         8 . A method of font data streaming, the method comprising steps as follows:
 subdividing a media stream into data segments, the media stream including character data and font data;   analyzing text content of a data segment to determine required fonts and an initial character set coverage for that data segment;   for each required font, generating and storing into memory a font subset that comprises only glyphs necessary for the initial character set coverage;   transmitting the font subset along with the respective data segment to a receiving device; and   transmitting a subsequent font subset that comprises additional glyphs for character set coverage of a subsequent data segment that has not been previously sent;   wherein said steps reduce redundancy in font data transmissions through reducing total number of characters for data transmitted during any given transmission to said receiving device.   
     
     
         9 . The method of  claim 8 , wherein said transmitting of said subsequent font subset comprises:
 analyzing text content of a subsequent data segment to determine required fonts and character set coverage for the subsequent data segment;   for each required font, generating a current font subset that comprises only glyphs necessary for the character set coverage for the subsequent data segment;   comparing the current font subset with any previous font subset and removing from the current font subset those glyphs that have been sent in a previous font subset, to produce a reduced font subset;   storing the reduced font subset in memory; and   transmitting the reduced font subset along with the subsequent data segment to a receiving device.   
     
     
         10 . The method of  claim 9 , further comprising:
 storing the previous font subset at the receiving device; and   updating the font subset stored at the receiving device by adding the reduced font subset to the stored previous font subset.   
     
     
         11 . The method of  claim 8 , wherein each font subset and its respective data segment are transmitted and stored at a first device, and subsequently transmitted and stored at other devices. 
     
     
         12 . The method of  claim 8 , wherein the font subsets are stored at a server.