JP2002051298A - Reproduction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproduction apparatus that can realize a high number of revolutions at a low cost while suppressing the circuit scale for detecting electronic watermark information. SOLUTION: A signal is read from a disk 2 driven by a spindle motor 6 and whether the signal is a video signal is detected. When the video signal is detected, the transfer rate of the video signal transferred to an electronic watermark information detection circuit 10 is decreased e.g. by reducing the speed of the spindle motor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video signal in which digital watermark information having copy control information is embedded in a video signal.
The present invention relates to a reproducing apparatus for reproducing a disk such as a VD.

[0002]

2. Description of the Related Art In a recently developed recording medium such as a DVD, a large amount of data for one movie, for example, can be recorded as digital information on one medium. As it becomes possible to record digital information, it becomes increasingly important to prevent unauthorized copying and protect copyright holders.

[0003] For example, Japanese Patent Application Laid-Open No. H11-155125 discloses a technique for preventing unauthorized copying of video information. This is to prohibit the output of information read from the disc from the playback device to the recording device side in the playback device when the copy control information of the digital watermark information embedded in the video signal is copy prohibited. It is.

[0004]

However, in general, such a circuit for detecting digital watermark information requires a large amount of memory, and has a problem that the circuit scale is large because the amount of operation is large. . In addition, when high-speed data transfer is realized by high rotation of the disk as in an optical disk device, it is necessary to reduce the calculation time for digital watermark detection. Since it is necessary to absorb the increase in the number, the circuit scale tends to increase. further,
Embedding digital watermark information that is not easily read results in an increase in the amount of computation. Therefore, when the application to an optical disk device is considered, there is a limit to how much the disk can be rotated at a higher speed, so that cost must be sacrificed for higher performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reproducing apparatus capable of realizing a high-speed rotation of a disk at a low cost while suppressing a circuit scale for detecting digital watermark information. The purpose is.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, a main aspect of the present invention is to be able to reproduce a disk on which a video signal in which digital watermark information having copy control information is embedded is recorded. A reproducing apparatus, comprising: a spindle motor for rotating the disk; reading means for reading a signal from the disk rotated by the spindle motor; and a video signal detecting means for detecting whether the read signal is a video signal or not. Digital watermark information detecting means for detecting digital watermark information from the video signal when the video signal is detected, and transferring to the digital watermark information detecting means when the video signal is detected by the video signal detecting means. Transfer rate lowering means for lowering the transfer rate of the video signal to be transmitted, and the electronic watermark detected by the digital watermark information detecting means. Based on the copy control information of the visible information is for and a restricting means for restricting an output of said video signal.

In the present invention, when a video signal is detected,
Since the transfer rate of the video signal transferred to the digital watermark information detecting means is reduced, the circuit size for detecting the digital watermark information can be reduced. Also,
When the signal is other than a video signal, the disk can be rotated at a high speed without considering digital watermark information, so that the disk can be rotated at a high cost at a low cost.

Another aspect of the present invention is a reproducing apparatus capable of reproducing a disk on which a video signal in which digital watermark information having copy control information is embedded is recorded,
Means for reading a signal from the disk, a memory for storing the read signal for at least one frame of a video signal, detection means for detecting whether or not the signal stored in the memory is a video signal, Detecting means for detecting digital watermark information from the video signal when is detected, and regulating means for restricting the output of the video signal based on copy control information of the detected digital watermark information. is there.

That is, the host connected to the reproducing apparatus according to the present invention is configured to read data in units of one sector, that is, in units of 2 KB. For DVD,
The signal from the disk is one ECC block, that is, 32 KB.
The data is decoded in units and stored in the host transfer buffer. When one piece of video information is reproduced, the host side reads out the video information continuously. When two pieces of video information are reproduced at the same time, these video information are at least EC.
The data is cut in units of 32 KB on the C decode side and in units of 2 KB on the host side. On the other hand, digital watermark information embedded in video information usually requires processing in units of one frame.
Even in the case of I-Picture included in TS / PS of PEG-2 Video (MP @ ML), if there is no data of about 2 MB after ECC decoding, I-picture of one frame
Picture cannot be configured. Therefore, when two or more pieces of video information are reproduced at the same time, it is impossible to detect these pieces of digital watermark information, and it is not possible to realize copy control which is the original purpose of the digital watermark. On the other hand, the present invention has a memory for storing a signal read from a disk for at least one frame of a video signal, and detects whether or not the signal stored in the memory is a video signal. Then, since the digital watermark information is detected and detected from the video signal, the digital watermark information can be detected even when two or more pieces of video information are reproduced at the same time.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing a configuration of an optical disc apparatus for reproducing an optical disc such as a DVD according to a first embodiment of the present invention.

As shown in FIG. 1, a turntable 1 is loaded with a disk 2 to be reproduced and recorded, and the turntable 1 is rotated by a spindle motor 3 so that the disk 2 rotates.

An optical pickup 4 for irradiating the rotating disk 2 with a laser beam and extracting information from the reflected light is slidable in the disk radial direction by a so-called sled mechanism (not shown). ing.

The signal readout circuit 5 demodulates and decodes the signal read out by the optical pickup 4 to make it a signal that can be transferred to the host (not shown).

The interface controller 7 buffers read data transferred from the signal read circuit 5 and exchanges commands with the host side.
The read data is transferred to and from the host via an interface 8 such as I / IEEE1394.

An MPEG-2 video bit stream (V
The video output from the signal readout circuit 5 is an MPEG-2 stream.
It is detected whether or not it is a Video Bit Stream. More specifically, the MPEG-2 video bit stream detection circuit 9 detects, for example, the P
program Stream (PS) or Transp
ort Stream (TS) to Packetize
d Elementary Stream (PES) is extracted and this Packetized Element is extracted.
Based on an early stream (PES), it is detected whether or not the data is an MPEG-2 Video BitStream, that is, whether or not the data is a video signal.

The spindle rotation control circuit 6 is an MPEG-
The rotation of the spindle motor 3 is controlled in accordance with the result of the detection of the video signal by the two video bit stream detection circuit 9. Specifically, the spindle rotation control circuit 6 controls the spindle motor 3 to rotate at a high speed when the signal is not a video signal, and regulates the spindle motor 3 to a low rotation when the signal is a video signal.

The digital watermark detection circuit 10 is an MPEG-2
The data output from the signal readout circuit 5 to the interface controller 7 by the video bit stream detection circuit 9 is MPEG-2 Video Bit S.
stream is detected, the MPEG-2 video bit stream detection circuit 9 outputs the MPEG-2 Vi
The video bit stream is received and this MPE
The digital watermark information embedded in the G-2 VideoBitstream is detected, and the contents of the digital watermark information are recognized.

Here, the digital watermark information is, for example, as disclosed in Japanese Patent Application Laid-Open No. H11-155125.
The luminance signal of the video signal is processed within a range in which the luminance of the video signal does not visually affect much, and information is embedded in the video signal. The digital watermark information includes copy control information. The copy control information includes “copy free”, “copy once”, “no more copy is impossible (No More Copy)”, and “copy prohibited”. There is information of. The data transfer stop determination circuit 11 outputs the result to the interface controller 7 according to the logic shown in Table 1 below.

[0019]

[Table 1]

Next, the operation of the optical disk device configured as described above will be described. First, the disk 2 is rotated by the spindle motor 3, and the optical pickup 4 causes the focus tracking servo (Focus Trackin).
g Servo) to read out the signal, and perform decoding processing in the signal readout circuit 5 to obtain data that can be transferred to the host side. This data is buffered by the interface controller 7 and sent to the host by SCSI.
The data is transferred via an interface such as / ATAPI / IEEE1394.

This data is stored in an MPEG-2 Stream.
m or data for uses other than video such as a file system. The data output from the signal reading circuit 5 is an MPEG-2 Video Stream.
MPEG-2 Video St sent to the detection circuit 9
It is determined whether or not it is a “ream”, and the result of the determination is transmitted to the spindle rotation control circuit 6.

In response to the result, the spindle rotation control circuit 6 controls the spindle motor 3 so that the MPEG-2
If the Video bit Stream does not exist, the rotation speed of the disk 2 is set to a high rotation, and if it does exist, the rotation speed is set to a low rotation. At the same time, MPEG-2 Video
If bit stream exists, this bit
stream is MPEG-2 Video Stream
The signal is sent from the detection circuit 9 to the digital watermark detection circuit 10, and the operation of the digital watermark detection circuit 10 is started.

Here, during the operation of the digital watermark detection circuit 10, the disk 2 rotates at a low rotation speed, and the processing after the signal readout circuit 5 can suppress the throughput lower than at the high rotation speed.

In the digital watermark detection circuit 10, the MPEG-
2 Copy free embedded in Video bitstream, 1-time copy possible, No More Co
Either py or copy prohibition information is recognized, and the result is sent to the data transfer stop determination circuit 9.

The data transfer stop determination circuit outputs the result to the interface controller 7 according to the logic shown in Table 1.

The interface controller 7 determines whether or not to send data to the host from the result. Normally, data is sent by a READ command from the host side. When the transfer is continued, the READ command is completed normally. To suspend the transfer, use READ command
To inform C that the command cannot be completed
Com at the Heck Condition status
end of the mand.

As described above, according to the optical disk apparatus of the first embodiment, data transfer at a high rotation speed can be realized in the case of ordinary data, and the rotation speed can be reduced only in the case of video information requiring copy protection. The load on the signal processing circuit can be reduced. In many cases, video information is compressed and used in such a way that data transfer at high rotation is not required. Therefore, it is possible to realize, at low cost, an optical disk device that enables copyright protection using digital watermark information while maintaining high performance. In addition, by rotating the disk at a low rotation speed, the quality of the signal from the disk can be improved, specifically, the error rate can be reduced, and the detection rate of digital watermark information embedded in video information can be improved. Can be. This means that digital watermark information can be detected in a short time, and the transfer amount of video information for which copyright needs to be protected can be reduced. Therefore, from the viewpoint of copyright protection, an optical disk device with higher reliability can be realized. It should be noted that a mechanism for detecting whether the read video signal is scrambled by a method such as CSS or CPRM is provided. If the signal is scrambled, it is considered that sufficient protection has already been applied, and A configuration may be adopted in which the steps of paragraph numbers 0015 to 0026 are skipped. (Second Embodiment) FIG. 2 is a block diagram showing a configuration of an optical disk device according to a second embodiment of the present invention.

The optical disc apparatus shown in FIG. 2 is different from the optical disc apparatus according to the first embodiment in that the optical disc apparatus further includes a media discriminating circuit 12. Here, the media determination circuit 12 is a circuit that determines whether the optical disk is read-only or writable. For example, DVD-R, DVD-R
Writable media such as W, DVD + RW, and DVD-RAM have wobbles, and DVD-ROMs, which are read-only media, do not have wobbles. To

In the data transfer stop determination circuit according to the present embodiment, the result is output to the interface controller 5 according to the following logic.

[0030]

[Table 2]

In this embodiment, the result of the media determination circuit is also used as a criterion for data transfer control.
Precise data transfer control can be performed in correspondence with various media including a writable disk such as a VD-RAM. A mechanism for detecting whether the read video signal is scrambled by a method such as CSS or CPRM is provided. If the signal is scrambled, it is considered that sufficient protection has already been provided and the paragraph number 0015-
A configuration may be adopted in which the process of paragraph number 0030 is skipped. (Third Embodiment) FIG. 3 is a block diagram showing a configuration of an optical disk device according to a third embodiment of the present invention.

The optical disk apparatus shown in FIG. 3 further comprises a decoder memory 13 and a buffer memory 14, and further comprises an MPEG-2 Video Frame detection circuit 15 instead of the MPEG-2 Video Stream detection circuit 9. The configuration is different from that of the optical disk device according to the embodiment. Here, the decoder memory 13 stores the 1 ECC Bloc decoded by the signal readout circuit 5.
Data of k (32 KB) units are stored. This data is buffered in the buffer memory 14 and transferred to the host via the interface controller 7.

The data read from the disk is MPE
In some cases, the data may be G-2 Stream, and in other cases data other than video, such as a file system. MPEG-
The 2 Video Frame detection circuit 15 outputs the data output from the signal readout circuit 5 as MPEG-2 Video.
o Stream or not, and MPEG-2Vi
If the stream is a “deo stream”, the circuit determines whether the frame is the start or end of the frame. Pro
Gram Stream (PS) or Transpo
Packetized from rt Stream (TS)
Extract Elementary (PES), MPE
Frame of G-2 Video bit Stream
The start and end of e are determined, and the result is transmitted to the signal readout circuit 5.

The signal readout circuit 5 receives the result and continues the decoding process until one frame of MPEG-2 Video is completed.
Transfer to the video frame detection circuit 15. At the same time, data is stored in the buffer memory 14 to prepare for a transfer request from the host.

The MPEG-2 Video Frame detection circuit 15 sends a continuous 1 Fr to the digital watermark detection circuit 10.
A bit stream of ame is sent, and the processing of the digital watermark detection circuit 10 is unfolded. In order for the digital watermark detection circuit 10 to determine digital watermark information, a plurality of frames of M
Requires PEG-2 Video Stream.
Until the judgment is completed, the interface controller 7
The above-described processing is repeated in response to a read request from the host side to. The control for stopping the data transfer is performed in the same manner as in the above-described embodiment.

In the present embodiment, in particular, even when the host side simultaneously reproduces two or more pieces of video information from the disk, ECC decoding is performed at least in units of one frame, and data is transferred to the digital watermark detection circuit. Accordingly, the digital watermark information can be detected with certainty, and copy control and reproduction control of video information can be performed.

The above-described embodiment is an effective method when the video information to be reproduced simultaneously has the same digital watermark information. However, in actuality, it is necessary to consider a case where simultaneously reproduced video information has different digital watermark information, and the processing described in the above embodiment is not sufficient. Therefore, a configuration may be adopted in which consecutive read requests are recognized as described below, an identification number is assigned to each frame, and independent digital watermark detection is performed for each identification number.

The procedure will be described below. First, in response to a read request from the host, the signal read circuit 5
Start VD decoding. If the MPEG-2 Video Frame is detected from the DVD decoded data, the address requested to be read is stored as the digital watermark processing address. At the same time, Fr
Assign an ame ID. Frame I allocated
D is stored in the digital watermark detection circuit 10 so as to correspond to the frame being processed. Then, when the next read request from the host side is received, the continuity with the stored digital watermark processing address is checked, and when the frames are continuous, the extracted frame is processed by the digital watermark detection circuit 10. Specify the same Frame ID. On the other hand, if the next read request from the host does not have continuity with the stored digital watermark processing address, it is checked whether or not there is MPEG-2 Video Frame in the DVD decoded data, and the frame is detected. Then, a new Frame ID is allocated, and the digital watermark detection circuit 10
, The new Frame ID and the detected frame data are input. The digital watermark detection circuit 10 uses the Frame I
Digital watermark detection processing is performed independently for each D, and the result is
This is transmitted to the data transfer stop determination circuit 11 together with the frame ID. The data transfer stop judgment circuit 11 determines the judgment result and
The frame ID is transmitted to the interface controller 7. The interface controller 7 reads the read request address from the host and the stored Frame I
Check the correspondence with D and compare it with the Frame ID from which data transfer must be stopped based on the determination result.
Command is terminated by Check Condition, and the host is notified that the read request cannot be completed.

Here, an assignable Frame ID
Should be determined depending on the processing capability of each device such as digital watermarking processing, MPEG-2 decoding processing on the host side, transfer speed of a drive, access time, and the like. For example, a value that can be realized at that time, such as four, eight, or sixteen, may be set as the upper limit.

[0040]

As described above, according to the present invention,
High-speed rotation of the disc can be realized at low cost while suppressing the circuit scale for detecting the digital watermark information. Further, according to the present invention, it is possible to detect digital watermark information even when two or more pieces of video information are reproduced simultaneously.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an optical disc device according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of an optical disc device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Turntable 2 Disc 3 Spindle motor 4 Optical pickup 5 Signal readout circuit 6 Spindle rotation control circuit 7 Interface controller 9 MPEG-2 video bit stream detection circuit 10 Digital watermark detection circuit 11 Data transfer stop judgment circuit 12 Media judgment circuit 13 Decoder memory 14 Buffer Memory 15 MPEG-2 Video Frame Detection Circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H04N 7/08 H04N 7/08 Z 7/081 F term (Reference) 5C052 AA04 AB02 AC02 BC05 CC11 DD10 5C053 FA13 FA24 FA25 GB17 GB38 HA23 HA40 JA30 KA03 5C063 AB03 AB07 AB13 AC01 AC05 CA23 CA40 DA20 5D044 FG18 GK08 GK12 GK17 HH13 HL08 JJ03

Claims (8)

[Claims] 1. A reproducing apparatus capable of reproducing a disk on which a video signal having digital watermark information having copy control information embedded therein is recorded, comprising: a spindle motor for rotating the disk; and a spindle motor for rotating the disk. Reading means for reading a signal from a disk to be rotated; video signal detecting means for detecting whether the read signal is a video signal; and, when the video signal is detected, digital watermark information from the video signal. Digital watermark information detecting means for detecting; a transfer rate lowering means for lowering a transfer rate of a video signal transferred to the digital watermark information detecting means when a video signal is detected by the video signal detecting means; The output of the video signal is regulated based on the copy control information of the digital watermark information detected by the information detecting means. A playback device, comprising: 2. The reproducing apparatus according to claim 1, wherein said transfer rate lowering means reduces the rotation speed of said spindle motor when said video signal detecting means detects a video signal. Playback device. 3. The reproducing apparatus according to claim 1, further comprising: a memory for accumulating at least one frame of a signal read by the reading unit for at least one frame of the video signal, wherein the video signal detecting unit. Detecting whether the signal read from the memory is a video signal, the digital watermark information detecting means detects the digital watermark information from the video signal when the video signal is detected, A reproducing apparatus for controlling output of the video signal based on copy control information of the digital watermark information detected by the digital watermark information detecting means. 4. A reproducing apparatus capable of reproducing a disk on which a video signal in which digital watermark information having copy control information is embedded is recorded, wherein: a means for reading a signal from the disk; A memory for accumulating at least one frame of the detected signal for at least one frame of a video signal; detecting means for detecting whether the signal stored in the memory is a video signal; A reproducing apparatus comprising: detecting means for detecting information; and restricting means for restricting output of the video signal based on copy control information of the detected digital watermark information. 5. The reproducing apparatus according to claim 1, further comprising: means for detecting whether or not the video signal is scrambled. Playback device. 6. The reproducing apparatus according to claim 1, further comprising: means for determining whether the disc is a writable medium or a read-only medium. Characteristic playback device. 7. The playback device according to claim 1, wherein the playback device is configured to perform the playback device according to the detected digital watermark information, the scramble detection result, or the media determination result. A playback device further comprising means for determining whether to stop or continue data transfer to a host connected to the playback device. 8. The reproducing apparatus according to claim 1, wherein the copy control information includes:
There are information of "copy free", "copy once", "copy no more" and "copy prohibited". The restricting means sets the copy control information as "copy once", "no more" Copy is not allowed "or" Copy is prohibited "
Wherein the output of the video signal is regulated.