Transcoding Video Data

• US 20100266009A1
• Filed: 04/15/2010
• Published: 10/21/2010
• Est. Priority Date: 04/18/2009
• Status: Active Grant

• Current Assignee: Neulion, Limited (Endeavor Group Holdings Inc.)
• Original Assignee: Saffron Digital Limited (Endeavor Group Holdings Inc.)
• Inventors: Sedeffow, Peter Vassilev
• Granted Patent: US 8,724,691 B2
• Time in Patent Office: Days
• US Class Current: 375/240.20
• CPC Class Codes: H04N 1/00 Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
• CPC Class Codes: H04N 1/0083 Arrangements for transferring signals between different components of the apparatus, e.g. arrangements of signal lines or cables for control or supervision between image input and output device H04N1/32
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/149 by estimating the code amount by means of a model, e.g. mathematical model or statistical model
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 21/23 Processing of content or additional data; Elementary server operations; Server middleware
• CPC Class Codes: H04N 21/234354 by altering signal-to-noise ratio parameters, e.g. requantization
• CPC Class Codes: H04N 21/2381 Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/6437 Real-time Transport Protocol [RTP]
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Video data is transcoded on the fly to produce a progressive download viewed while the data is being received while streaming and/or may be downloaded and played later. An analyser analyses a portion of an input video data file to determine coded characteristics of encoded input video and determines an expected data volume. A generator generates a file header for output video data that includes an indication of the expected volume thereof. A transcoder transcodes the input video data to produce encoded output video data. The output interface supplies the encoded output video data with the file header as a stream to a receiving device. In a first embodiment, the expected volume of data in the header is overestimated and blank video chunks added. In an alternative embodiment, the expected data of volume is underestimated and compression parameters are modified during the transcoding process.

Claims

1. A method of transcoding encoded input video data to produce encoded output video data, comprising the steps of:

locating an input video data file;

analysing a portion of said input video data file to determine coding characteristics of encoded input video data contained within said input video data file;

determining an expected data volume by estimating the amount of data that would be present in an output video data file created by transcoding said input video data file;

creating a file header for an output video data file, said header including said estimated data volume;

receiving the encoded input video data located by said locating step;

transcoding received encoded input video data to produce encoded output video data; and

supplying said encoded output video data with said file header as a stream to a receiving device,

such that said receiving device is adapted to at least one of;

view the output video data as it is received as a stream and

store the output video data with the file header as a downloaded file.

2. The method of claim 1, wherein said step of locating an input video data file includes being notified of an internet location from a receiver and locating said input video data file at the location notified by the receiver.

3. The method of claim 1, wherein said analysing step includes analysing a file extension of the input video data file.

4. The method of claim 1, wherein said analysing step includes analysing a file header.

5. The method of claim 1, wherein said analysing step includes analysing portions of data contained within a body of the file.

6. The method of claim 5, wherein said step of analysing portions of data contained within the body of the file includes issuing binary offsets to specify a location within the file and reading a predetermined number of bytes from said location within the file.

7. The method of claim 1, wherein said step of creating a file header includes creating an indication of the number of tracks present in the output video data.

8. The method of claim 1, wherein said step of estimating the amount of data comprises estimating the number of data chunks that would be present in the output video data file.

9. The method of claim 1, wherein said transcoding step transcodes input video data that has been configured for streaming to fixed location devices.

10. The method of claim 8, wherein said transcoding step transcodes said input video data for at least one of:

streaming to mobile devices and

downloading to mobile devices.

11. The method of claim 1, wherein said step of supplying said encoded output video data includes the step of monitoring the volume of output video data being produced during the transcoding operation to ensure that the volume of output video data produced is consistent with said expected data volume.

12. The method of claim 11, wherein said expected data volume is made lower than a best estimate of the expected data volume and the data volume of the output data is reduced during the transcoding operation to make the output data volume fit the expected data volume.

13. The method of claim 12, wherein the data volume of the output data is reduced by increasing data compression during a re-coding operation that forms part of the transcoding step.

14. The method of claim 11, wherein the expected data volume is made higher than a best estimate and redundant data are created at the end of the encoded output video data.

15. The method as claimed in claim 14, wherein said redundant data includes one of:

blank data and

data conveying a message.

16. An apparatus for transcoding encoded input video data to produce encoded output video data, comprising:

a locator for locating an input video data file;

an analyser for analysing a portion of said input video data file to determine coding characteristics of encoded input video data contained within said input video data file, and for determining an expected data volume by estimating the amount of data that would be present in an output video data file created by transcoding said input video data file;

a generator for generating a file header for an output video data file that includes an indication of said expected data volume;

an input interface for receiving the input video data located by said locator;

a transcoder for transcoding the input video data to produce encoded output video data; and

an output interface for supplying the encoded output video data with said file header as a stream to a receiving device, such that

said receiving device is adapted to at least one of;

view the output video data as it is received as a stream and

store the output video data with the file header as a downloaded file.

17. The apparatus of claim 16, wherein said output interface includes a monitoring device for monitoring the volume of output video data supplied as a stream to the receiving device to check that the volume of output data produced is consistent with the expected data volume as specified in the header.

18. The apparatus of claim 17, wherein the indication of the expected data volume produced by the generator is made larger than a best estimate of output data volume and said transcoder produces additional output video data to ensure consistency.

19. The apparatus of claim 17, wherein the indication of the expected data volume is made smaller than a best estimate and the transcoder controls data compression in response to an output from said monitoring device to ensure consistency.

20. A computer-readable medium having computer-readable instructions executable by a computer such that when executing said instructions a computer will perform the steps of:

locating an input video data file;

analysing a portion of said input video data file to determine coding characteristics of encoded input video data contained within said input video data file;

determining an expected data volume by estimating the amount of data that would be present in an output video data file created by transcoding said input video data file;

creating a file header for an output video data file, said header including said estimated data volume;

receiving the encoded input video data located by said locating step;

transcoding received encoded input video data to produce encoded output video data; and

supplying said encoded output video data with said file header as a stream to a receiving device,

such that

said receiving device is adapted to at least one of;

view the output video data as it is received as a stream and

store the output video data with the file header as a downloaded file.