VIDEO IMAGE INFORMATION PLAYBACK METHOD AND VIDEO IMAGE INFORMATION PLAYBACK DEVICE

• US 20140169762A1
• Filed: 05/23/2012
• Published: 06/19/2014
• Est. Priority Date: 10/21/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Ryu, Tomoaki
• Granted Patent: US 9,020,331 B2
• Time in Patent Office: Days
• US Class Current: 386/259
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/12 Protecting executable software
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 2220/2541 Blu-ray discs; Blue laser DVR discs
• CPC Class Codes: G11B 27/102 Programmed access in sequence to addressed parts of tracks of operating record carriers access by moving the head G11B3/08, G11B5/54, G11B7/085, G11B21/022; by moving the record carrier G11B15/005, G11B17/005, by driving of both record carrier and head G11B15/1816
• CPC Class Codes: G11B 27/105 of operating discs

Abstract

A video image information playback method and a video image information playback device with which user convenience can be obtained at the start of resume playback. The video image information playback method is a method of playback of a recording medium on which virtual-machine-based content has been recorded. During normal playback of the virtual-machine-based content, a program running on a virtual machine and a decryption program that decrypts encrypted virtual-machine-based content perform decryption processing for the virtual-machine-based content while exchanging data. After suspension of playback of the virtual-machine-based content, at the start of resume playback, which is executed following an instruction to resume playback, a proxy program is launched in place of the program that runs on the virtual machine. The proxy program and the decryption program perform playback of the video image of the virtual-machine-based content while exchanging data.

Claims

1. A video image information playback method for causing a video image information playback device to playing back a recording medium, the video image information playback device comprising a playback unit for playing back the recording medium on which virtual-machine-based content is recorded, enabling video playback to be controlled by a program running on a virtual machine, and a playback control unit for controlling execution of the program running on the virtual machine and playback processing in the playback, wherein:

in normal playback of the virtual-machine-based content, a decryption support program, which is one of the plurality of programs running on the virtual machine, receives a numeric value from a decryption program for decrypting encrypted virtual-machine-based content;

the decryption support program executes a prescribed computation by using the numeric value;

the decryption program executes a decryption process by using a result of the computation; and

at the start of resume playback, which is executed following an instruction to resume playback after playback of the virtual-machine-based content is suspended, a proxy program for carrying out a computational process equivalent to the decryption support program in place of the decryption support program that runs on the virtual machine in the playback control unit, and the video playback of the virtual-machine-based content is executed as the proxy program exchanges data with the decryption program.

2. The video image information playback method of claim 1, wherein:

when the virtual-machine-based content is played back, data exchanges between the decryption support program running on the virtual machine and the decryption program are detected, and a flag value indicating whether such data exchanges are performed or not is set according to detected results; and

at the start of resume playback, whether or not to launch the proxy program is determined from the flag value.

3. The video image information playback method of claim 1, wherein:

when the virtual-machine-based content is played back, a fixed value used in a computation in the proxy program that communicates with the decryption program is retrieved from the program that runs on the virtual machine; and

at the start of resume playback, the proxy program is executed by use of the retrieved fixed value.

4. A video image information playback device, comprising:

a playback unit for playing back a recording medium on which virtual-machine-based content is recorded, enabling video playback to be controlled by a program running on a virtual machine; and

a playback control unit for controlling execution of the program running on the virtual machine and playback processing in the playback unit, wherein;

in normal playback of the virtual-machine-based content, a decryption process for the virtual-machine-based content is executed by a decryption support program running on the virtual machine in the playback control unit and a decryption program for decrypting the encrypted virtual-machine-based content running on a decryption control unit in the playback unit; and

at the start of resume playback, which is executed following an instruction to resume playback after playback of the virtual-machine-based content is suspended, a proxy program for carrying out a computational process equivalent to the decryption support program in place of the decryption support program that runs on the virtual machine in the playback control unit, and the video playback of the virtual-machine-based content is executed as the proxy program exchanges data with the decryption program.

5. The video image information playback device of claim 4, wherein:

when the virtual-machine-based content is played back, the playback control unit detects data exchanges between the decryption support program running on the virtual machine and the decryption program, and sets a flag value indicating whether such data exchanges are performed or not according to detected results; and

at the start of resume playback, whether or not to launch the proxy program is determined from the flag value.

6. The video image information playback device of claim 4, wherein:

when the virtual-machine-based content is played back, the playback control unit retrieves a fixed value used in a computation in the proxy program that communicates with the decryption program from the program that runs on the virtual machine; and

at the start of resume playback, the playback control unit executes the proxy program by using the retrieved fixed value.