JP2004007344A - Optical disk reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a optical disk reproducing apparatus capable of making a sub-picture information including caption corresponding to a character string not displayed when a predetermined character string exists in decoded closed caption information. <P>SOLUTION: The optical disk reproducing apparatus is composed of a determining means which determines whether the predetermined character string exists or not in the decoded closed caption information, and an inhibiting means which inhibits the display of sub-picture information that includes a caption corresponding to the character string determined to be included in the decoded closed caption information among decoded sub-picture information when the predetermined character string is determined to exist in the decoded closed caption information. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical disk reproducing apparatus for reproducing an optical disk such as a DVD.
[0002]
[Prior art]
Some DVDs (Digital Versatile Disk) record a compressed bit stream including video information, audio information, sub-picture information (caption information), and closed caption information. The closed caption information refers to closed caption text data, which is one type of subtitle data.
[0003]
A DVD reproducing apparatus for reproducing such a DVD has a function of reading a bit stream from a DVD, decoding the read bit stream into original video information, sub-picture information, audio information, and closed caption information, and performing reproduction. Some have. In this type of DVD reproducing apparatus, the decoded video information and the decoded sub-picture information are mixed, and the mixed video signal is added (superimposed) with the decoded closed caption information and output.
[0004]
In addition, in order to prevent children from hearing or showing inappropriate words, some DVD reproducing devices of this type use inappropriate words and the like included in closed caption information as other words. A character string conversion table for replacement is provided, and it is determined whether or not an inappropriate character string registered in the character string conversion table exists in the decoded closed caption information. A device having a function of replacing the inappropriate character string in the closed caption information with another character string according to a character string conversion table and muting the audio output for a certain period of time has already been developed.
[0005]
As described above, in the conventional DVD reproducing apparatus, it is possible to replace inappropriate words included in the closed caption information with other words and to mute the sound for a certain period when such replacement occurs. There is a problem that sub-picture information (caption information) cannot be replaced because it is not text data.
[0006]
Further, in the conventional DVD reproducing apparatus, an inappropriate word included in the closed caption information is replaced with another word, and when such replacement occurs, the sound is muted for a certain period. When muted, there is a problem that sound effects and BGM (background music) as well as human voice (voice) are muted.
[0007]
[Problems to be solved by the invention]
The present invention relates to an optical disc reproducing apparatus capable of not displaying sub picture information including subtitles corresponding to a predetermined character string in the decoded closed caption information when the character string exists in the closed caption information The purpose is to provide.
[0008]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and the character string It is an object of the present invention to provide an optical disc reproducing apparatus capable of preventing display of subpicture information including a corresponding subtitle.
[0009]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and audio output can be performed for a predetermined period. It is an object of the present invention to provide an optical disk reproducing apparatus that can be muted and that does not display subpicture information including a subtitle corresponding to the character string.
[0010]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and audio data can be transmitted for a certain period of time. It is an object of the present invention to provide an optical disc reproducing apparatus capable of muting only a human voice included in a signal and not displaying subpicture information including a caption corresponding to the character string.
[0011]
Further, the present invention provides an optical disc reproducing apparatus capable of muting only a human voice included in an audio signal for a predetermined period when a predetermined character string exists in decoded closed caption information. With the goal.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 reads a bit stream from a recording medium in which a compressed bit stream including video information, sub-picture information, audio information, and closed caption information is recorded, and reads the read bit stream into an original video. In an optical disc reproducing apparatus having a function of decoding information, sub-picture information, audio information, and closed caption information and performing playback, whether or not a predetermined character string exists in the decoded closed caption information Determining means for determining whether or not a predetermined character string exists in the decoded closed caption information, when the decoded closed caption information includes Is determined to exist in the above Wherein the sub-picture information that may contain closed caption corresponding to the string is provided with prohibiting means for prohibiting from being displayed.
[0013]
According to a second aspect of the present invention, in the optical disk reproducing apparatus according to the first aspect, when the prohibiting means determines that a predetermined character string exists in the decoded closed caption information, It is characterized in that the contents of the buffer storing the decoded sub-picture information are cleared.
[0014]
According to a third aspect of the present invention, in the optical disk reproducing apparatus according to the first or second aspect, when it is determined that a predetermined character string exists in the decoded closed caption information, It is characterized by having means for replacing a character string with another character string.
[0015]
According to a fourth aspect of the present invention, in the optical disk reproducing apparatus according to the first to third aspects, when it is determined that a predetermined character string exists in the decoded closed caption information, the audio is reproduced. It is characterized by having a means for muting the output for a certain period.
[0016]
According to a fifth aspect of the present invention, in the optical disc reproducing apparatus according to any one of the first to third aspects, when it is determined that a predetermined character string exists in the decoded closed caption information, a predetermined value is set. During the period, a means for removing a voice signal from an audio signal and outputting the signal is provided.
[0017]
The invention according to claim 6 reads a bit stream from a recording medium in which a compressed bit stream including video information, sub-picture information, audio information, and closed caption information is recorded, and reads the read bit stream into an original video. In an optical disc reproducing apparatus having a function of decoding information, sub-picture information, audio information, and closed caption information and performing playback, whether or not a predetermined character string exists in the decoded closed caption information Determining means for determining whether or not a predetermined character string is present in the decoded closed caption information, and means for removing a voice signal from a voice signal for a predetermined period of time and outputting the same. It is characterized by having.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a DVD playback device will be described with reference to the drawings.
[0019]
[1] Description of Configuration of DVD Playback Device
FIG. 1 shows a schematic configuration of a DVD reproducing apparatus.
[0021]
A drive unit 11 reads information from a DVD disk. Reference numeral 13 denotes a demultiplexer that separates the bit stream received from the drive unit 11 into video information, audio information, sub-picture information (caption information), and closed caption information. Each piece of information separated by the demultiplexer 13 is compressed information.
[0022]
Reference numeral 14 denotes a video decoder for expanding the compressed video information obtained by the demultiplexer 13. Reference numeral 15 denotes an audio decoder that expands the compressed audio information obtained by the demultiplexer 13. Reference numeral 20 denotes a mute circuit for muting audio. Reference numeral 16 denotes a sub-picture decoder for expanding the compressed sub-picture information obtained by the demultiplexer 13. Reference numeral 17 denotes a closed caption decoder for expanding the compressed closed caption information obtained by the demultiplexer 13.
[0023]
Reference numeral 18 denotes a mixer for mixing a video signal output from the video decoder 14 and a video signal output from the sub-picture decoder 16. Reference numeral 19 denotes a video encoder that inserts a closed caption signal output from the closed caption decoder 17 into a video signal output from the mixer 18 and converts the signal into an analog video signal.
[0024]
Reference numeral 12 denotes a CPU that controls the entire system. Reference numeral 21 denotes a character string conversion table, which exists in a ROM accessible from the CPU 12. FIG. 2 shows the contents of the character string conversion table 21. As shown in FIG. 2, the character string conversion table 21 includes information on a plurality of character strings before conversion and information on a character string after conversion corresponding to each information on the character strings before conversion.
[0025]
The playback modes of the DVD playback device include a normal playback mode and a limited playback mode. In the restricted playback mode, inappropriate words included in the closed caption information are replaced with other words, and when such word replacement occurs, the sound is muted for a certain period and the sub-picture information ( Caption information) is not displayed for a certain period of time. On the other hand, in the normal reproduction mode, word replacement, audio mute control, and display prohibition control of sub-picture information (subtitle information) are not performed.
[0026]
[2] Description of operation in normal playback mode
In the normal reproduction mode, the CPU 12 does not perform the collation between the character string included in the closed caption information decoded by the closed caption decoder 17 and the character string conversion table 21, so that the character string included in the closed caption information is not used. Is not replaced.
[0028]
Therefore, after the video signal output from the video decoder 14 and the video signal output from the sub-picture decoder 16 are mixed by the mixer 18, the video signal output from the mixer 18 is output from the closed caption decoder 17. A closed caption signal without replacement of a character string is inserted by the video encoder 19, converted into an analog video signal, and output.
[0029]
In the normal reproduction mode, the replacement of the character string included in the closed caption information is not performed, so that the audio mute control based on the replacement of the character string is not performed.
[0030]
[3] Description of operation in restricted playback mode
In the restricted playback mode, the CPU 12 constantly monitors the closed caption information decoded by the closed caption decoder 17. The CPU 12 compares the character string included in the decoded closed caption information with the information of the character string before conversion in the character string conversion table 21, and determines that the character string included in the closed caption information is a character string. If it exists as the information of the character string before conversion in the conversion table 21, the character string is replaced with the information of the character string after conversion corresponding to the character string, and the replaced closed caption signal is sent to the video encoder 19. Send.
[0032]
Further, when the replacement of the character string included in the closed caption information occurs, the CPU 12 controls the audio mute circuit 20 to mute the audio output for a certain period. Further, when the replacement of the character string included in the closed caption information occurs, the CPU 12 sets a subtitle (sub-picture) including a character string similar to the character string before replacement to prevent the subtitle from being displayed. By clearing the sub-picture data (sub-picture unit (SPU) obtained after decoding) stored in the buffer in the picture decoder, the sub-picture information (subtitle information) is not displayed for a certain period.
[0033]
[3] Description of Modification Example
As shown in FIG. 3, instead of the audio mute circuit 20 of FIG. 1, a voice cancel circuit (vocal feeder) 20A for removing only a voice signal (a signal corresponding to a human voice) included in the audio signal. When the replacement of the character string included in the closed caption information occurs in the limited playback mode, only the voice signal may be removed from the voice signal by the voice cancel circuit 20A for a certain period. .
[0035]
It is assumed that a left-channel audio signal and a right-channel audio signal are input to the voice cancellation circuit 20A. As the voice cancel circuit 20A, for example, a voice cancel circuit disclosed in Japanese Patent Application Laid-Open No. 7-141759 can be used. In other words, since the voice signal in the audio signal is considered to be included in the audio signal of each of the left and right channels at substantially the same ratio and in the same phase, in principle, the audio signal of both the left and right channels is common. May be extracted, and the extracted voice signal may be removed from the audio signals of the left and right channels.
[0036]
According to this modification, when the replacement of the character string included in the closed caption information occurs, a signal in which only the voice signal is removed from the audio signal is output for a certain period, so that an inappropriate word is output. It is possible to prevent sound output, and also to output sound effects and BGM.
[0037]
【The invention's effect】
According to the present invention, when a predetermined character string is present in the decoded closed caption information, it is possible to prevent the display of sub-picture information including subtitles corresponding to the character string.
[0038]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and the character It is possible not to display the sub-picture information including the caption corresponding to the column.
[0039]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and audio output can be performed. It is possible to mute for a certain period and not to display sub-picture information that includes a caption corresponding to the character string.
[0040]
Further, according to the present invention, when a predetermined character string exists in the decoded closed caption information, the character string in the closed caption information can be replaced with another character string, and for a certain period of time. In addition, it is possible to mute only the human voice included in the audio signal, and not to display the sub-picture information including the caption corresponding to the character string.
[0041]
Further, according to the present invention, when a predetermined character string is present in the decoded closed caption information, only a human voice included in the audio signal can be muted for a certain period.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a DVD playback device.
FIG. 2 is a schematic diagram showing the contents of a character string conversion table 21.
FIG. 3 is a block diagram showing a modification.
[Explanation of symbols]
11 Drive unit 12 CPU
13 Demultiplexer 14 Video decoder 15 Audio decoder 16 Sub-picture decoder 17 Closed caption decoder 18 Mixer 19 Video encoder 20 Mute circuit 20A Voice cancellation circuit 21 Character string conversion table

Claims (6)

Reads a bit stream from a recording medium on which a bit stream composed of compressed video information, sub-picture information, audio information, and closed caption information is recorded, and reads the read bit stream as original video information, sub-picture information, audio information, and In an optical disc reproducing apparatus having a function of decoding to closed caption information and performing reproduction,
Determining means for determining whether or not a predetermined character string exists in the decoded closed caption information, and determining that a predetermined character string exists in the decoded closed caption information Prohibits the display of sub-picture information that may contain subtitles corresponding to the character string determined to be present in the decoded closed caption information among the decoded sub-picture information when Prohibition means,
An optical disc reproducing apparatus comprising: The prohibition means clears the contents of the buffer storing the decoded sub-picture information when it is determined that a predetermined character string exists in the decoded closed caption information. 2. The optical disk reproducing apparatus according to claim 1, wherein: 2. A device according to claim 1, further comprising means for, when it is determined that a predetermined character string exists in the decoded closed caption information, replacing the character string with another character string. 3. The optical disc reproducing device according to any one of claims 2 and 3. 3. The apparatus according to claim 1, further comprising: means for muting the audio output for a predetermined period when it is determined that a predetermined character string exists in the decoded closed caption information. 4. The optical disk reproducing device according to any one of 3. In the decoded closed caption information, when it is determined that a predetermined character string is present, it is provided with a means for removing a voice signal from a voice signal for a predetermined period and outputting the same. 4. An optical disk reproducing apparatus according to claim 1, wherein Reads a bit stream from a recording medium on which a bit stream composed of compressed video information, sub-picture information, audio information, and closed caption information is recorded, and reads the read bit stream as original video information, sub-picture information, audio information, and In an optical disc reproducing apparatus having a function of decoding to closed caption information and performing reproduction,
Determining means for determining whether or not a predetermined character string exists in the decoded closed caption information, and determining that a predetermined character string exists in the decoded closed caption information An optical disc reproducing apparatus, comprising: means for removing a voice signal from an audio signal for a predetermined period of time when the voice signal is output.

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