Apparatus and methods for presentation of key frames in encrypted content

• US 10,652,594 B2
• Filed: 07/07/2016
• Issued: 05/12/2020
• Est. Priority Date: 07/07/2016
• Status: Active Grant

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Inventors: Chen, John, Belt, David, Galt, III, Edward, Smith, Robert Todd
• Primary Examiner(s): Shaw, Peter C
• Application Number:
  US15/204,610
• Publication Number:
  US 20180014041A1
• Time in Patent Office: 1,405 Days
• Field of Search: 380210
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• 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

Abstract

Apparatus and methods for presentation of key frames. In one embodiment, an encoded video file is generated where one or more bits are assigned to key frames and minimizes the number of bits assigned to delta frames. Each key frame may be presented to a user during trick mode operation (e.g., fast forward, rewind, pause, or random seek operation). When the encoded video file is given to a packager, the packager generates a manifest file listing the byte information (byte offset and number of bytes) for each key frame in the encoded video file. When a user inputs a trick play mode command, the packager provides the manifest file to the client device of the user and the client device requests the bytes for the key frames of the video file from the content delivery network.

Claims

1. Computer readable apparatus comprising a non-transitory storage medium, the non-transitory medium comprising at least one computer program having a plurality of instructions, the plurality of instructions configured to, when executed on a digital processing apparatus, cause a computerized packager apparatus to:

receive a digitally rendered video file for use with adaptive bitrate streaming, the digitally rendered video file comprising one or more key frames;

generate manifest data for the digitally rendered video file, the manifest data comprising a listing of byte information for the one or more key frames;

provide the manifest data for delivery to a computerized client device;

receive data representative of a request for trick play mode operation, the request comprising data indicative of a key frame of the one or more key frames, a byte offset, and a number of bytes of the key frame;

retrieve a portion of the digitally rendered video file referenced by the byte offset and the number of bytes included in the request;

decrypt the retrieved portion of the digitally rendered video file, the retrieved portion of the digitally rendered video file comprising the key frame and a plurality of key frames immediately preceding and immediately following the key frame; and

transmit the decrypted portion of the digitally rendered video file to the computerized client device;

wherein the computerized packager apparatus is disposed at a headend of a content delivery network, the headend being upstream from the computerized client device.

2. The computer readable apparatus of claim 1, wherein the plurality of instructions are further configured to, when executed on the digital processing apparatus:

retrieve and transmit one or more bytes of the digitally rendered video file immediately following the portion of the digitally rendered video file referenced by the byte offset and the number of bytes included in the request to be buffered for immediate full resolution playback of the digitally rendered video file.

3. The computer readable apparatus of claim 1, wherein the plurality of instructions are further configured to, when executed on the digital processing apparatus:

generate one or more key frame files from the digitally rendered video file, the one or more key frame files comprising a consecutive sequence of key frames; and

for each key frame of the consecutive sequence of key frames, (i) retrieve one or more bytes of the digitally rendered video file preceding and corresponding to the key frame to enable decryption of the key frame, (ii) decrypt the retrieved one or more bytes, and (iii) extract one or more bytes corresponding to the key frame from the decrypted one or more bytes;

wherein the generation of the one or more key frame files comprises generation from the extracted one or more bytes corresponding to the key frames; and

wherein transmission of the retrieved portion of the digitally rendered video file to the computerized client device comprises transmission of one or more portions of the one or more key frame files to the computerized client device.

4. The computer readable apparatus of claim 3, wherein the digitally rendered video file comprises protected media data, and the plurality of instructions are further configured to, when executed on the digital processing apparatus:

encrypt the one or more key frame files to maintain protection applied to portions of the protected media data included in the one or more key frame files.

5. The computer readable apparatus of claim 1, wherein the plurality of instructions are further configured to, when executed on the digital processing apparatus:

segment the digitally rendered video file into a plurality of portions for delivery via the network; and

generate a master manifest file comprising a plurality of addresses corresponding to the plurality of portions of the segmented digitally rendered video file.

6. A computerized packager apparatus, comprising:

a first data interface configured to communicate with a data network;

a processor apparatus in data communication with the first data interface; and

a storage apparatus in data communication with the processor apparatus and comprising at least one computer program, the at least one computer program comprising a plurality of instructions which are configured to, when executed by the processor apparatus, cause the computerized packager apparatus to;

receive digitally rendered video file for use with adaptive bitrate streaming, the digitally rendered video data comprising one or more key frames;

generate manifest data for the digitally rendered video file, the manifest data comprising a data structure of byte data for the one or more key frames;

provide the manifest data for delivery to a computerized client device;

receive data representative of a request for trick play mode operation, the data representative of the request comprising data indicative of a key frame of the one or more key frames, a byte offset, and a number of bytes of the key frame;

access a portion of the digitally rendered video file referenced by the byte offset and the data related to the number of bytes, the portion of the digitally rendered video file comprising the key frame and a plurality of key frames immediately preceding and immediately following the key frame;

decrypt the portion of the digitally rendered video file; and

cause transmission of the decrypted portion of the digitally rendered video file to the computerized client device;

wherein the computerized packager apparatus is disposed at a headend of a content distribution network, the headend located upstream from the computerized client device.

7. The computerized packager apparatus of claim 6, wherein the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

segment the digitally rendered video file into a plurality of portions for delivery via the data network.

8. The computerized packager apparatus of claim 7, wherein the manifest data further comprises a plurality of network addresses corresponding to respective ones of the plurality of portions of the segmented digitally rendered video file.

9. The computerized packager apparatus of claim 6, wherein the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

receive data representative of a request for a plurality of key frames; and

generate key frame data comprising a consecutive sequence of the plurality of key frames.

10. The computerized packager apparatus of claim 6, wherein the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

cause modification of at least one of resolution, bit rate, or aspect ratio of the portion of the digitally rendered video file, the modification prior to the transmission of the decrypted portion of the digitally rendered video file to the computerized client device and based at least on data relating to one or more capabilities of the computerized client device.

11. The computerized packager apparatus of claim 6, wherein the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

encode the portion of the digitally rendered video file, the encoding based at least on data relating to one or more capabilities of the computerized client device, at least a portion of the encoding performed prior to the transmission of the decrypted portion of the digitally rendered video file to the computerized client device.

12. The computerized packager apparatus of claim 6, wherein the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

receive and transmit one or more bytes of the digitally rendered video file immediately following the portion of the digitally rendered video file referenced by the byte offset and the data related to the number of bytes, the one or more bytes to be buffered for immediate full resolution playback of the portion of the digitally rendered video file.

13. The computerized packager apparatus of claim 6, wherein:

the decryption of the portion of the digitally rendered video file comprises decryption of one or more bytes; and

the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to;

extract one or more bytes corresponding to the key frame from the decrypted one or more bytes; and

generate one or more key frame files from the extracted one or more bytes corresponding to the key frame; and

wherein the causation of the transmission of the decrypted portion of the digitally rendered video file to the computerized client device comprises transmission of the one or more key frame files to the computerized client device.

14. The computerized packager apparatus of claim 13, wherein the digitally rendered video file comprises protected media data, and the plurality of instructions are further configured to, when executed by the processor apparatus, cause the computerized packager apparatus to:

encrypt the one or more key frame files to maintain protection applied to portions of the protected media data included in the one or more key frame files.

15. A computerized method for providing image data for rendering, the computerized method comprising:

receiving a digitally rendered video data structure comprising one or more key frames;

generating manifest data for the digitally rendered video data structure, the manifest data comprising a data structure of byte information for each of the one or more key frames;

providing the manifest data for delivery to a computerized client device;

receiving data representative of a request for trick play mode operation, the data representative of the request comprising data indicative of a key frame of the one or more key frames, a byte offset, and a number of bytes of the key frame;

based at least on the request, obtaining a portion of the digitally rendered video data structure referenced by the byte offset and the number of bytes of the key frame, the obtained portion comprising the key frame and a plurality of key frames immediately preceding and immediately following the key frame;

decrypting, by a computerized packager apparatus, the portion of the digitally rendered video data structure; and

causing transmission of the decrypted portion of the digitally rendered video data structure to the computerized client device;

wherein the computerized packager apparatus is disposed at a headend of a content delivery network, the headend being upstream from the computerized client device.

16. The computerized method of claim 15, further comprising:

causing buffering of the portion of the digitally rendered video data structure in support of uninterrupted full resolution playback of the digitally rendered video data structure.

17. The computerized method of claim 15, further comprising:

generating one or more key frame files from the digitally rendered video data structure, the one or more key frame files comprising a consecutive sequence of key frames; and

for each key frame of the consecutive sequence of key frames, extract one or more bytes corresponding to the key frame;

wherein the generating of the one or more key frame files comprises generating based on the extracted one or more bytes corresponding to the key frame.

18. The computerized method of claim 15, further comprising:

segmenting the digitally rendered video data structure into a plurality of portions for delivery via the network; and

generating a master manifest file comprising a plurality of addresses corresponding to the plurality of portions of the segmented digitally rendered video data structure.

19. The computerized method of claim 15, wherein the receiving of the data representative of the request for the trick play mode operation comprises receiving data generated in response to a user input to effect a trick play mode command.

20. The computerized method of claim 15, wherein the receiving of the digitally rendered video data structure comprises receiving an encrypted digitally rendered video file.