Patent Application
20050111832
1. Field of the Invention
The present invention relates to a technique for generating a data stream after reception of an image, audio or other signal and writing the data stream to a recording medium such as an optical disc.
2. Description of the Related Art
A technique has been hitherto known for recording pictures to a film such as a silver salt film and playing back the pictures as a movie (more specifically, a cinema movie). A cinema movie, for example, is a “film material video” (film video) shot and screened using a film. Ordinary cinema movies are shown at the rate of 24 frames a second.
On the other hand, NTSC (National Television Standards Committee) system video (NTSC video)—NTSC employed in Japanese and US television broadcasting—is shot at 30 frames a second (to be precise, 29.97 frames a second). Since one frame of image consists of two fields of images (an odd and an even field), NTSC video is shot and played back at approximately 60 fields a second (to be precise, 59.94 fields a second).
To record film video created at 24 frames a second using NTSC-compliant equipment, the 24-frame-per-second video must be converted to 30-frame 60-field-per-second NTSC video (so-called telecine conversion) to ensure consistency between respective video types.
Here, we consider the process by which NTSC video, converted from 24-frame-per-second film video with the 2-3 pull-down system, is recorded to a medium (e.g., DVD-RAM disc). Japanese Patent Application Laid-Open Publication No. 1993-183864, for example, discloses a recording/playback device having a pull-down detection circuit for efficient encoding of the video signal.
It is to be noted that the playback process is conducted as described below in the recording/reproduction device 320. A playback section 1202 reads out the moving picture stream from the DVD-RAM disc 131 via the pickup 130 based on an instruction from a playback controller 1203. A moving stream decoder 1111 decodes the moving picture stream of the film video that has been read out and at the same time proceeds with a 2-3 pull-down conversion to output the stream as NTSC video, outputting an NTSC video signal from a video signal output section 1110. When audio data is contained in the moving picture stream, the moving stream decoding section 1111 also decodes the audio data, outputting the data as an audio signal from an audio signal output section 1112.
Recent years have seen establishment of the DV and DVD standards, with progress made in the camera performance improvement. For example, consumer-oriented high-performance video cameras capable of shooting HDTV video are commercially available at affordable prices, allowing easy shooting of high-quality moving pictures. On the other hand, an environment is in the making where various moving picture content including cinema movies can be distributed without degradation as a result of proliferation of recording/playback devices using digital recording media such as a DVD recorder and widespread use of personal computers (hereinafter “PCs”), the Internet and others.
As a result of proliferation of equipment, content created/copied unlawfully without the copyright owner's consent (so-called “pirated” content) is in circulation, threatening the rights of copyright owners. For example, content made by shooting a cinema movie being shown in a theater with a video camera is in circulation. Since the cinema movie being shot generally involves a copyright, countermeasures are needed to protect the copyright. In particular, shooting a cinema movie being shown using a high-performance video camera capable of shooting HDTV video results in a sufficiently watchable cinema movie with high image quality being copied, requiring immediate countermeasures.
It is an object of the present invention to judge whether the shot target is video subject to copyright protection and limit the recording of the video if the video is subject to copyright protection.
A data processing apparatus according to a preferred embodiment of the present invention is used to record a video stream related to video to a recording medium. The data processing apparatus preferably includes a signal acquisition section, a type identification section, a stream generator, a controller and a writing section. The signal acquisition section preferably acquires a video signal related to the video. The type identification section preferably identifies a type of the video based on the video signal. The type of the video is determined in accordance with picture counts of the video displayed per unit time. The stream generator preferably generates a video stream based on the video signal. The controller preferably determines, based on the type of the video, whether to disable the writing of the video stream or to enable the writing of the video stream with lowered video quality. The writing section preferably controls, based on the decision of the controller, the writing of the video stream to the recording medium.
In one preferred embodiment of the present invention, the controller preferably disables the writing of the video stream in the case where the type of the video is a movie.
In this particular preferred embodiment, the data processing apparatus further includes an adjustment section. The adjustment section preferably selects a video quality based on the type of the video. The stream generator preferably generates the video stream with selected video quality.
More specifically, in the case where the type of the video matches a predetermined type, the controller preferably determines to enable the writing of the video stream with lowered video quality. The adjustment section preferably selects video quality lower than that set in advance.
In another preferred embodiment, in the case where the type of the video does not match a predetermined type, the controller preferably determines to enable the writing of the video stream with the video quality preserved. The adjustment section preferably selects the same video quality as set in advance.
In still another preferred embodiment, the adjustment section preferably selects the video quality in relation to a resolution.
In yet another preferred embodiment, the type identification section preferably includes a detection section and a judgement section. The detection section preferably continuously receives the video signal and preferably detects whether first and second images consisting of each picture of the video, match or mismatch. The judgement section preferably judges the type of the video based on the detection result.
In still another preferred embodiment, the detection section preferably includes a first memory, a second memory, and a comparator. The first memory preferably stores data of the first image. The second memory preferably stores data of the second image. The comparator preferably compares the data in the first memory with that in the second memory and preferably detects whether the first and second images match each other.
More specifically, the judgement section continuously preferably receives each detection result and preferably specifies the type of the video based on a pattern of match and mismatch appeared in the each detection result.
In another preferred embodiment, the data processing apparatus further includes a management information generator. The management information generator preferably generates judgement information indicating at which of a first resolution and a second resolution lower than the first resolution the video was encoded. The management information generator preferably manages the judgement information in association with the video stream. The writing section further writes the judgement information to the recording medium.
In still another preferred embodiment, the management information generator preferably manages a plurality of contents, each of which includes a pair of the judgement information and the video stream associated with each other. The data processing apparatus further includes a management file generator. The management file generator preferably extracts the judgement information from each content and preferably generates a content management file having entries for each content.
A data processing apparatus according to a preferred embodiment of the present invention is used to read out a video stream related to video from a recording medium to output a video signal. The video stream and management information are preferably written on the recording medium. The management information preferably contains judgement information indicating the video being encoded in first video quality and second video quality lower than the first video quality. The data processing apparatus preferably includes a readout section, an extraction section, a decoder, and an output section. The readout section preferably reads out the video stream and the management information from the recording medium. The extraction section preferably extracts the judgement information from the management information and preferably generates, based on the judgement information, quality display data indicating at which of the first video quality and the second video quality the video was encoded. The decoder preferably decodes the video stream to generate a video signal. The output section preferably outputs the quality display data and the video signal in correspondence with each other.
In yet another preferred embodiment, in the case where the type of the video matches a predetermined type, the judgement information preferably indicates that the video was encoded at the second video quality. In the case where the type of the video does not match a predetermined type, the judgement information preferably indicates that the video was encoded at the first video quality.
In one preferred embodiment of the present invention, the data processing apparatus further includes a superimposing processor. The superimposing processor preferably superimposes the quality display data on the video signal. The output section preferably outputs the video signal superimposed with the quality display data.
In this particular preferred embodiment, the output section preferably includes a video signal output section which preferably outputs the video signal, and a display output section which preferably displays the quality display data.
More specifically, a plurality of contents are stored on the recording medium, each of which includes a pair of the judgement information and the video stream associated with each other, each piece of the judgement information is preferably stored in a content management file having an entry for each piece of the content. The extraction section preferably extracts the judgement information from the content management file to generate list data for displaying content corresponding to each entry and the quality display data in correspondence with each other.
A data processing method according to a preferred embodiment of the present invention is used to write a video stream related to video on a recording medium. The data processing method preferably includes steps of: acquiring a video signal related to the video; identifying a type of the video based on the video signal, the type of the video being determined in accordance with picture counts of the video displayed per unit time; generating a video stream based on the video signal; determining, based on the type of the video, whether to disable the writing of the video stream or to enable the writing of the video stream with lowered video quality; and controlling, based on the determination, the writing of the video stream to the recording medium.
In another preferred embodiment, the step of determining preferably determines to disable the writing of the video stream in the case where the type of the video is a movie.
In still another preferred embodiment, the data processing method further includes a step of selecting a video quality based on the type of the video. The steps of generating preferably generates the video stream with selected video quality.
In yet another preferred embodiment, in the case where the type of the video matches a predetermined type, the step of determining preferably determines to enable the writing of the video stream with lowered video quality. The step of selecting preferably selects video quality lower than that set in advance.
Other features, elements, processes, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
The above and other objects, aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Embodiments of the data processing apparatus according to the present invention will now be described with reference to the accompanying drawings. In the embodiments below, description will be made assuming that the data processing apparatus is a video camera.
In the present specification, description will be given using the terms defined as described below.
Video: Image displayed by switching a plurality of pictures one after another at a given vertical scan frequency. For example, the vertical scan frequency for switching 30 pictures per unit time (one second) is 30 Hz. The Video may include moving pictures and still images, texts such as subtitles and graphics.
Picture: Frame image composed of two field images, one of which is made from odd lines and the other of which from one even lines, in the interlaced system. Picture is one frame image in the progressive system. Picture encompasses both the frame and the field. It is to be noted that one picture of video (in particular, one picture of the video recorded on a reel of film) is also occasionally referred to as “one frame.” The interlaced system is not employed in ordinary cinema movies. Each of the cinema movies is shown by switching 24 pictures (i.e. 24 frames) per second.
SD (Standard Definition) video: Video in standard resolution quality (480i video in the NTSC system, 576i video in the PAL system).
HD (High Definition) video: Video in high resolution quality other than the above SD video (e.g., HDTV video).
More specific examples, related to moving pictures of SD and HD video, are shown in Tables 1 and 2. Note that 24p or 23.976p HD video in Table 2 is called film material video.
iInterlaced scan
pProgressive scan
iInterlaced scan
pProgressive scan
The video camera 1 has a camera section 100, a microphone 101, a moving picture stream generator 102, a controller 105, a writing section 106, a video signal output section 110, an audio signal output section 111, a moving picture stream decoder 112, a playback controller 115, a playback section 116, a video type identification section 119 and a pickup 130. Note that The DVD-RAM disc 131, shown in
Description will be given below of the components of the video camera 1 and then of the operation of the video camera 1.
First, description will be made on the components related to the recording capability of the video camera.
The camera section 100 receives light from a shot target and generates, for example, a digital signal of NTSC interlaced system. That is, the video camera 1 acquires a digital video signal using the camera section 100. The camera section 100 includes, for example, an optical system such as a lens, a CCD element and analog/digital (A/D) converter (not shown). Light received by the camera section 100 includes not only light reflected after striking a person, object, scenery, etc. but also, in the present embodiment, light reflected by the screen after being projected thereonto. That is, the video camera 1 may shoot video such as a cinema movie projected onto the screen as the target. When shooting an ordinary cinema movie which is projected to be shown by switching 24 pictures per second, the camera section 100 shoots the target using a CCD element with shutter speed faster than field frequency 60 Hz (or {fraction (1/60)} second) in NTSC system. Note that appropriate exposure is preferably obtained with the shutter speed. The camera section 100 outputs an NTSC interlaced video signal in an analog format. A/D converter converts the video signal in the analog format into that of digital format and outputs the signal.
The microphone 101 receives voice being shot and generates an audio signal in the analog format. Microphone 101 is equipped with A/D converter which converts the audio signal in the analog format into that in the digital format and outputs the converted signal.
The moving picture stream generator 102 encodes the digital video and audio signals respectively with given encoding systems.
It is to be noted that, although the moving picture stream is described to contain video and audio data, it is sufficient for the preferred embodiment that at least the video data is contained in the moving picture stream. The MPEG-2 program stream is an example of system stream defined by the MPEG2 System Standard (ISO/IEC 13818-1). In this system stream, transport stream (TS) and PES stream are defined in addition to program stream (PS). The present invention is applicable even if the moving picture stream is an MPEG-2 transport stream. In the present embodiment, the data structures of these streams are not specifically important, and description thereof is omitted herein.
Description will be given next of the video type identification section 119 with reference to
The video type identification section 119 has a detection section 103 and a judgement section 104. The detection section 103 includes first and second memories 1031 and 1032 and a comparator 1033.
Video signal input to the detection section 103 is received by the first and second memories 1031 and 1032 and stored therein. Each of the two memories 1031 and 1032 stores data of a picture. For example, assuming that one picture is constructed by two field images, the memory 1031 stores data of one field image and the memory 1032 stores the other field image. The comparator 1033 compares, at a display time interval of one-field image (approx. {fraction (1/60)} second), the stored contents in the first and second memories 1031 and 1032 and outputs a comparison result. The comparison is performed by calculating difference between the stored content of the first memory 1031 and that of the second memory 1032. The comparison result is output, which indicates whether the difference is 0 or not, that is, the respective stored content in the memories 1031 and 1032 make a match or a mismatch. In the case where the video signal contain noise, the difference may be calculated after the noise is removed using such as a digital filter.
As for a progressive-scanned video, the first and second memories 1031 and 1032 may store each data of frame images, since one picture corresponds to one frame image. In the case where a progressive-scanning type camera is used, the progressive-scanned video signal is output. Based on the signal, the first and second memories 1031 and 1032 store data of progressive-scanned frame images at the rate of 60 frames per second which are used for comparing the difference.
In
When a given period L1 elapses after the updating operation of the first memory 1031, the comparator 1033 proceeds with the comparison operation. At this time, the stored contents of the first and second memories are respectively “frame B” and “frame A”, thus leading to the comparison result being an “mismatch.” The comparison result is hold until a next comparison is carried out.
At a time t2, approximately {fraction (1/60)} second after the time t1, the second memory 1032 stores the frame B data. At this point in time, the “frame B” data is stored in both the first and second memories 1031 and 1032. Therefore, the comparison result of the comparator 1033 at the pulse trailing edge after a lapse of period L2 from the time t2 is a “match.”
At a time t3, approximately {fraction (1/60)} second after the time t2, since the frame B video signal continues to be output from the camera section 100, the first memory 1031 stores the “frame B” data again and the second memory 1032 also has the “frame B” data stored therein. Since the stored contents in the memories 1031 and 1032 are not changed at the comparison timing after a lapse of period L3 from the time t3, the comparison result is a “match.”
On the other hand, the shot target changes from the “frame B” to the “frame C” in {fraction (1/24)} second after the time t1. Later at a time t4 ({fraction (1/60)} second after the time t3), therefore, the “frame C” data is stored in the second memory 1032. The comparison result is an “mismatch” because the first memory 1031 has the “frame B” stored therein whereas the second memory 1032 has the “frame C” data stored therein at the comparison timing after a lapse of period L4 from the time t4.
Thereafter, the stored contents of the memories 1031 and 1032 are updated in succession, producing, as a result of the comparisons, a comparison result in which “match” and “mismatch” are repeated in a constant order in a cycle D.
The detection section 103 repeats the above-described comparisons and outputs respective comparison results.
The judgement section 104 of the video type identification section 119 continuously receives the comparison results from the detection section 103, and judges whether a pattern obtained from a series of “match” and “mismatch” coincide with a specified pattern or not. The “specified pattern” appears in the case where the shot target is 24-picture-per-second video (i.e. cinema movie). In this preferred embodiment, the “specified pattern” is shown in
The judgement section 104 judges that the shot target is not the 24-picture-per-second video or a cinema movie, when “mismatch” continues in the comparison result of the detection section 103 as shown in
Note that, in
Referring back to
The writing section 106 controls the writing of the moving picture stream on the DVD-RAM disc 131 based on the decision made by the controller 105. More specifically, the writing section 106 does not write the moving picture stream if the writing of the moving picture stream is disabled by the controller 105. When the writing is not disabled, the writing section 106 writes the file to the DVD-RAM disc 131 via the pickup 130. The written moving picture stream is managed as a chronological data file on the file system. It is to be noted that the moving picture stream is also referred to as chronological data.
Description will be given next of the components related to the playback capability of the video camera 1.
The playback controller 115 instructs the readout of the user-specified chronological data file, a moving picture stream. The playback section 116 manipulates the pickup 130, optically reading out the chronological data file specified by the playback controller 115 and acquiring the file as the moving picture stream. The moving picture stream decoder 112 separates video and audio data respectively from the moving picture stream for decoding, thus generating video and audio signals. The resolution of the decoded video is the same as the resolution at the time of the encoding or less. The video signal output section 110 is, for example, an liquid crystal display (LCD) device (not shown) and changes pictures one after another based on the video signal, thus playing back the video. The audio signal output section 111 is, for example, a speaker and plays back the audio signal as sounds. It is to be noted that the video camera 1 can output the chronological data file played back from the DVD-RAM disc 131 to external equipment via a digital interface (not shown) compliant with a standard such as the IEEE1394 Standard.
Description will be given next of the recording process of the video camera 1.
First in step S001, the video camera 1 generates chronological data or a moving picture stream. The chronological data is generated as the camera section 100 and the microphone 101 output video and audio signals, and as the moving picture stream generator 102 encodes these signals.
In step S002, the detection section 103 and the judgement section 104 of the video type identification section 119 judge the video picture count (frame count) per second of the subject based on the video signal output from the camera section 100.
In step S003, the controller 105 judges whether the video frame count is 24 frames per second. If the frame count is not 24 frames per second, the process proceeds to step S004. When the frame count is 24 frames per second, the process proceeds to step S005.
In step S004, the controller 105 enables the writing of the moving picture stream. In response to enabling of the writing, the writing section 106 writes the moving picture stream to the DVD-RAM disc 131. In step S005, on the other hand, the controller 105 disables the writing of the moving picture stream by judging the shot target as being a cinema movie. As a result, the writing section 106 halts the writing. The process ends following step S004 or S005.
When a subject other than a cinema movie (e.g., a person or scenery described in relation to
The video camera according to the embodiment 1 disables the writing of the moving picture stream if the shot target is 24-picture-per-second video.
The video camera according to the present embodiment writes the moving picture stream at a lowered video quality if the shot target is 24-picture-per-second video.
The video camera 2 is provided with a resolution adjustment section 107 that receives the output of the video type identification section 119 and adjusts the video resolution based on the output. The resolution adjustment section 107 selects a resolution lower than that set during the shooting by the user when the type of the video identified by the video type identification section 119 is a cinema movie. For example, if the video camera 2 is set up by the user to perform the recording at the NTSC system's 1080i video quality (HD image quality) and if the video picture count is identified as 24 pictures per second, the resolution adjustment section 107 selects a resolution such that the recording is performed at the NTSC system's 480i (SD quality). On the other hand, the resolution adjustment section 107 selects the same resolution as is set in advance during the shooting if the type of the video is not a cinema movie, thereby the resolution is preserved. The resolution adjustment section 107 notifies the selected resolution to a moving picture stream generator 202.
When a moving picture stream is generated, the writing section 106 writes the moving picture stream to the DVD-RAM disc 131. Note that the controller 105 enables the writing of the moving picture stream to the writing section 106. In the present embodiment, the controller 105 does not disable the writing.
In step S012, the resolution adjustment section 107 judges whether the video frame count is 24 frames per second. If the frame count is not 24 frames per second, the process proceeds to step S013. When the frame count is 24 frames per second, the process proceeds to step S014. In step S013, the resolution adjustment section 107 selects a resolution lower than that set by the user in advance.
In step S014, the moving picture stream generator 202 performs the encoding at the selected resolution, generating chronological data (moving picture stream). When the process branches from step S012, the user-specified resolution will be employed. The controller 105 determines to enable the writing of the moving picture stream, and in response to enabling of the writing, the writing section 106 writes the chronological data file of the moving picture stream to the DVD-RAM disc 131 via the pickup 130.
The above process allows the video camera 2 to write the moving picture stream at a lowered video quality if the shot target is cinema movie, thus protecting the copyright of the cinema movie.
It is to be noted that in the above description, if the shot target is judged as being a cinema movie based on the picture count (frame count) per second, the resolution adjustment section 107 lowers the resolution during the encoding. The resolution adjustment section 107 can arbitrarily select a resolution from the range shown in the above-described Table 1. However, an arbitrary resolution may be employed as long as the resolution falls within the range compliant with the video standard. The moving picture stream is played back in conformity with the resolution at the time of the encoding.
Attention can be called to the copyright infringement during later distribution and the copyright protected by lowering the faithfulness to the shot target, for example, through the recording with a message superimposed on the video signal, through the recording after mosaicing the video, through the recording at a lowered frame rate (picture count per second) (e.g., 5 pictures per second), or through the recording of a black screen, in addition to the lowered resolution.
The video camera according to the present embodiment identifies a type of the video of the shot target, sets a resolution at the time of the encoding and, if the encoding is performed at a lowered resolution, generates information (judgement_information) indicating this fact, and writes the information together with the moving picture stream to the recording medium.
First, when the video signal is encoded at a resolution lower than that set at the time of the shooting by the moving picture stream generator 202, the management information generator 108 generates judgement information indicating the fact. Details of the judgement information will be described later with reference to
The management file generator 109 generates a management file containing the judgement information which is generated by the management information generator 108.
Here, the management file will be described referring to
The management information stores the information for managing the playback of the moving picture stream video stored in the chronological data file 12. With the management information, the video-related information is managed in units called “video tracks.” The video tracks include position information for each access unit (access information) and encoding information. In the present embodiment, the judgement information makes up part of the encoding information and is stored in the management information. These pieces of information, generated during the writing of the moving picture stream, are used for random access at the time of the playback of the moving picture stream. The management information also includes link information for identifying the corresponding moving picture stream. The link information is, for example, the file name (“MOV001.MPG”) of the chronological data file storing the corresponding moving picture stream.
The moving picture stream 11 includes a plurality of samples (P2 Sample) 15. The samples 15 includes video and audio data mixed together. The samples 15 can be defined based on the video playback time, the data size (data volume) and other factors, and includes video data of 0.4 to one second in video playback time such as a DVD video object unit (VOBU). A set of one or more of the samples 15 is called a chunk 16.
Referring back to
Description will be given next of the type of criterion used in the management information 13 to define the samples 15 and the chunks 16. We assume, for example, that the video and audio data having approximately 0.4 to one second in video playback time is dealt as the one sample (P2 Sample) 15. The access information for each of the samples is written to the management information 13. Then, once a resolution is determined that is commonly applied to a series of video, the section corresponding to these pieces of video is handled as the single chunk 16, with the encoding information 19—information common to the samples in each of the chunks—defined. Among examples of “a series of video” are pieces of video shot by the video camera that are continuous from start to end of the recording. The access information for each of the chunks can be set in the management information 13. It is to be noted that although the section of a series of video with a common resolution has been descried as the criterion for defining the chunks, the chunks may be defined based on other criterion not particularly relevant to the present invention.
The moving picture stream generator 202 and the management information generator 108 generate the moving picture stream 11 and the management information 13 based on the above-described data structures and criterion.
The sample table atom 18 further has a plurality of atom fields 311 to 316. Of these fields, attention is focused on the sample description atom 311, the sample size atom 312, the decoding time to sample atom 313, the sample to chunk atom 314 and the chunk offset atom 315.
In the sample description atom 311, the encoding information applied to the video within that sample is defined. In the sample size atom 312, the data size of that sample is defined. In the decoding time to sample atom 313, the video playback time of that sample is defined. In the sample to chunk atom 314, the number of samples included in a chunk is defined. In the chunk offset atom 315, the top position (offset) of each of the chunks is defined that is calculated, for example, from the top of the chronological data file. It is to be noted that “#0” written in the atoms 312 to 315 indicates that the data is for the 0th sample or chunk and followed by the first, second and succeeding pieces of data that are not shown.
In step S104, the moving picture stream generator 202 performs the encoding process at the selected resolution, generating chronological data (moving picture stream). Then, the management information generator 108 generates judgement information. More specifically, if the process branches from step S102, the moving picture stream generator 202 encodes the video at the resolution set by the user in advance, whereas the management information generator 108 generates judgement information (“00”) corresponding to that process. On the other hand, when the process in step S103 is performed, the moving picture stream generator 202 encodes the video at a lower resolution instructed by the resolution adjustment section 107, whereas the management information generator 108 generates judgement information (“01”) corresponding to that process. It is to be noted that when the management information generator 108 generates judgement information, the management file generator 109 generates management information such as encoding information including that judgement information.
In step S105, in response to enabling of the writing of the moving picture stream from the controller 105, the writing section 106 writes the chronological data file of the moving picture stream to the AV data area 133 of the DVD-RAM disc 131 via the pickup 130. The writing section 106 also writes the management file to the management information area 132 of the DVD-RAM disc 131.
The above process allows the video camera 3 to write the moving picture stream at a lowered video quality if the shot target is cinema movie, thus protecting the copyright of the cinema movie.
Description will be given next of the process in which the video camera 3 reads out the moving picture stream from the DVD-RAM disc 131 and plays back the video.
In step S202, the judgement information extraction section 121 analyzes the management file stored in the management information memory 120, extracting the judgement information.
In step S203, the moving picture stream decoder 112 decodes the moving picture stream of the moving picture file, acquiring video and audio signals. The video and audio signals are output respectively to the superimposing processor 122 and the audio signal output section 111.
In step S204, the judgement information extraction section 121 judges, based on the judgement information, whether the video was recorded at a lowered resolution at the time of the encoding. For example, when “01” is set as the judgement information, this means that the encoding was performed at a lowered resolution. In step S205, the judgement information extraction section 121 generates data showing whether the video was “recorded at a lowered resolution” (display data). Character data is, for example, used as the display data to make clear that the video has been encoded at a lowered resolution.
In step S206, the superimposing processor 122 superimposes the display data on the video signal to be played back. The video signal superimposed with the display data is output from the video signal output section 110.
“Recording information” represents the resolution at the time of the recording, with “SD” indicating the standard resolution and “DC” indicating that the recording was conducted at a lowered resolution (that a down conversion was performed). In
As described above, in the present embodiment, the video camera 3 detects whether a work such as a cinema movie was shot and records the video at a lowered resolution if the video camera 3 judges that the video is a copyrighted cinema movie or work. The video camera 3 retains, as the management information, the judgement information indicating whether the video was encoded at a lowered resolution and displays the video based on the judgement information at the time of the playback. The video camera 3 can notify the user that the recording was conducted at the “standard resolution”, irrespective of whether the encoding at the “high resolution” was initially set at the time of the recording. Therefore, based on the notification, the user can recognize inadvertent recording of a copyrighted work such as a cinema movie, thus preventing the user from mistaking the resolution change for a camera malfunction.
It is to be noted that the judgement information has been described as being stored chunk by chunk in the sample description entry 515 described in
On the other hand, a display/output section may be provided in the video camera 3 for showing the judgement information, instead of indicating whether or not the resolution is lowered, superimposed on the TV screen during playback of the video. The display/output section may be a vacuum fluorescent display, LED (light-emitting diode), lamp (electric bulb) or others. A drive circuit for driving these devices may be incorporated in the display/output section. Provision of the display/output section eliminates the need to use part of the video display area during the video playback, thus allowing presenting the user with necessary information while at the same time resolving the difficulty to see the played-back video. In this modification, the process of driving the display/output section is executed instead of the process of superimposing the display data in steps S205 and S206 in
The video camera according to the embodiment 3 has been described as generating judgement information for a moving picture stream and storing the judgement information in the DVD-RAM disc 131 as part of the management information.
The video camera according to the present embodiment generates judgement information for each of a plurality of the moving picture streams and stores the judgement information in the DVD-RAM disc 131 as part of each piece of the management information. Then, the video camera generates a content management file for managing the management information corresponding to each of the moving picture streams in a unified manner, storing the content management file in the DVD-RAM disc 131. It is to be noted that in the present embodiment, information equivalent to “judgement information” in the embodiment 3 is referred to as “content judgement information.”
It is to be noted, however, that the content management file generator 209 has the capabilities of the management file generator 109 and further has the capability of generating a content management file. On the other hand, the content judgement information extraction section 221 has the capabilities equivalent to those of the judgement information extraction section 121 and performs the equivalent processes. Therefore, the video camera 4 has the capabilities to generate information for judging whether the encoding was performed at a lowered resolution and to notify that information to the user.
Description will be given below of the data structure of the content management file with reference to
In each of the entries, attribute information related to the corresponding content is defined. The attribute information includes a recording date, shooting source, file size, link information and encoding-process-related information (encoding information). The recording date is the date and start/end times of the shooting. As for the shooting source, “Camera” is written to indicate that the shooting was conducted by the video camera 4, whereas if a TV broadcast program is recorded, for example, with a DVD recorder, the channel number is written. The encoding information, the same as that described in the embodiment 1, includes “content judgement information” corresponding to the judgement information. Further, the encoding information may include information related to “recording mode”, “encoding rate”, “resolution” and so on.
As with the judgement information in the embodiment 3, the encoding process is performed at the resolution set at the time of the shooting when the content judgement information is “00” and at a lowered resolution if the content judgement information is “01.” On the other hand, the encoding process is performed at an increased resolution when the content judgement information is “10,” It is to be noted that the meaning of “11” is undefined.
The content management file generator 209 generates the content management file shown in
The details of the playback process of the video camera 4 for playing back the video from the DVD-RAM disc 131 after writing various files to the DVD-RAM disc 131 are the same as those of the playback process of the video camera 3 according to the embodiment 3 (
Further in the present embodiment, a list of content can be shown using the content management file to confirm the details of the content written on the DVD-RAM disc 131.
As described above, the recording dates, shooting sources, encoding information and others are stored in the content management file. The content judgement information extraction section 221 extracts, for example, the encoding information from among these pieces of information, thus generating list data to show each piece of content in correspondence with the resolution of that piece of content. The list data is intended to show the correspondence in table form shown in
Here, the “Information” item in
In the present embodiment, the video camera 4 not only offers the same effect as with the video camera 3 according to the embodiment 3 but also stores, in the content management file, the judgement information such as that indicating whether the recording was performed at a lowered resolution and displays the information as necessary. In the presence of only content-by-content management files, showing a list takes time as this requires access to and analysis of each of the management files. However, storing the judgement information in the content management file contributes to faster display of the list.
It is to be noted that the individual entries of the content management file may further store the following information. Included among the information are that indicating that the content is a recording of the shot target that changes at the rate of 24 pictures per second, that indicating the video change cycle of the shot target (also called “frame rate”) and that indicating the presence/absence of overlapping fields/frames resulting from recording with 30 pictures in the stream instead of 24 pictures. Further storing these pieces of information allows making more information about the shot target known to the user.
In the above-described embodiments, the configurations and processes for image shooting with the video camera have been described. However, the present invention is applicable to a streaming and other video signals that are transferred through an electric communication circuit or a wireless circuit. In this case, the Ethernet terminal of the data processing device, for example, takes the place of the camera section 100 of the video camera in obtaining the video signal. On the other hand, the data structures described in the embodiments 3 and 4 are examples, and the data structure is not limited thereto. While in the embodiments according to the present invention, the detection of the video picture count has been explained using the field memories 1031 and 1032 as an example, frame memories or other devices may also be used.
Further, while in the embodiments according to the present invention, description has been given assuming that the type of the video to judge is a cinema movie with 24 pictures per second, this is an example, and numbers of the picture count value in accordance with the type of the video for detection can be arbitrarily set. On the other hand, a judgement to determine numbers of the picture count value may be made, by setting a given threshold time at the time of the detection, when one or more specified patterns are continuously detected for the duration of the threshold time or more. This ensures improved reliability.
Further, the present invention allows judging whether the shot video is a cinema movie or similar video by analyzing the details of the shot video.
When a photo-receiving device such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) is employed as the imaging device of the camera section, the effective pixel count (number of imaging elements in the imaging device actually used for image shooting) is smaller than the total pixel count (total number of imaging elements).
Further, by considering the imaging device's horizontal-to-vertical ratio (aspect ratio; e.g., 4:3), the aspect ratio of the effective pixel area during the shooting (4:3 or 16:9 horizontal-to-vertical) and further the following movie aspect ratios, judgement can be made between bright and dark light entering the imaging device, thus ensuring further accurate detection. That is, the standard size is 1.33:1, the vista size in the European standard is 1.66:1, the vista size in the US standard is 1.85:1, and the Cinemascope size is 1.85:1.
Analyzing the details of the shot video using these techniques allows judging whether the shot video is a cinema movie or similar video. Making judgement using the above analyses together with the detection as to whether the picture count per second is 24 pictures allows determining the shot object type with higher accuracy.
While in the embodiments according to the present invention, description has been given assuming that the recording is made on the optical disc such as a DVD-RAM, the recording may be made on a non-volatile memory device such as a semiconductor memory or a magnetic recording medium such as a harddisk. On the other hand, while description has been given taking the MPEG2 video stream as an example of the data stream to be written, other video streams including the MPEG4 video stream may be applied.
The recording and playback capabilities of the data processing device typified by a video camera function based on a computer program implementing such capabilities. The computer program can, for example, cause a computer system to function as a recording device and/or playback device if recorded on a recording medium such as a CD-ROM and circulated in the market or if transferred through an electric communication circuit such as the Internet.
According to various preferred embodiments of the present invention described above, a type of the video is identified based on the video signal, which is determined in accordance with picture counts of the video displayed per unit time. If the target shot by the camera is film video such as a cinema movie, the recording of the video is halted, or the recording the video with a sufficiently lowered resolution is performed. This prevents the copyright infringement of the content copyright owner, thus protecting the content.
This application is based on Japanese Patent Applications No. 2003-349248 filed on Oct. 8, 2003, No. 2004-072552 filed on Mar. 15, 2004 and No. 2004-291362 filed on Oct. 4, 2004, the entire contents of which are hereby incorporated by reference.
While the present invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention that fall within the true spirit and scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-349248 | Oct 2003 | JP | national |
| 2004-072552 | Mar 2004 | JP | national |
