JP4434894B2 - Video dubbing device - Google Patents

Description

  The present invention relates to a video dubbing apparatus for re-recording (dubbing) a video stream recorded on a recording medium such as a hard disk on another recording medium.

  As this type of video dubbing device, for example, a video dubbing device described in Patent Document 1 is known. This video dubbing device is provided as a device in which a hard disk drive (Hard Disc Drive) is built in an optical disc recorder of DVD (Digital Versatile Disc) standard. The outline of the video dubbing apparatus described in Patent Document 1 will be described below.

  That is, the video dubbing apparatus includes a control unit that performs video stream write control and read control on a hard disk and a DVD standard optical disc, a decoder that decodes the video stream read by the control unit, and the decoder And an encoder that encodes the video stream decoded by. Here, the encoder encodes the video stream by converting the data format such as the bit rate of the video stream.

In such a configuration, when a dubbing request for dubbing a video stream recorded on a hard disk, for example, to a DVD standard optical disk is input in this video dubbing apparatus, the video stream recorded on the hard disk is Read by the control unit. Then, the read video stream is fetched and decoded by the decoder, and the decoded video stream is fetched by the encoder, and the data format such as the bit rate is converted by the encoder. Encoding processing is performed in the form. Then, the video stream encoded by the encoder is further taken into the control unit and used for writing control on the DVD standard optical disc by the control unit, and the video recorded on the hard disk through the writing control. The stream is dubbed onto the DVD standard optical disc.
Japanese Patent Laid-Open No. 2003-224813

  By the way, in such a video dubbing apparatus, the dubbing mode relating to the data format such as the bit rate of the video stream dubbed to the DVD standard optical disc and the length of the dubbing time which is the time required for dubbing the video stream is usually , Selected by the user. Then, by performing the above-described processes according to the selected dubbing mode, the video stream is dubbed onto the DVD standard optical disc with a desired dubbing time and data format. However, regarding such a dubbing mode, a desired dubbing mode varies greatly depending on the time, such as a mode in which a video stream is dubbed with high quality and a mode in which the dubbing time is further shortened at the expense of the quality of the video stream. Therefore, it is more desirable for such a video dubbing apparatus to be able to select a dubbing mode having a high degree of freedom, that is, a data format such as a bit rate of a video stream, a dubbing time, and the like in a wide range.

Here, the dubbing time is a process that is a writing speed that is a speed at which data is written to a recording medium on which a video stream is dubbed and a speed of a data format conversion process itself such as a bit rate of the video stream. The speed is determined based on the slower speed. Of these, the writing speed is determined by the standard of the recording medium or the like. On the other hand, since the processing speed is determined by the bit rate (quality) of the video stream to be dubbed or the like, the bit rate of the video stream is actively converted to be low, so It is also possible to further shorten the dubbing time with the writing speed as an upper limit. However, in recent years, video dubbing devices equipped with a removable hard disk instead of the DVD standard optical disk have been developed, and the writing speed of the removable hard disk is more than 1000 times the playback speed. ing. Therefore, it is difficult to dubb a video stream at a speed corresponding to the writing speed with the conventional video dubbing apparatus, and as the video dubbing apparatus, the processing speed is higher than the writing speed of the recording medium itself. The situation is not necessarily followed.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a video dubbing apparatus that enables selection of a dubbing mode with a higher degree of freedom without depending on a recording medium.

  In order to achieve such an object, in the video dubbing device according to claim 1, a transcoder for converting the data format of the video stream read from the first video recording unit in which the video stream is recorded as compressed data, Based on a user instruction input signal for instructing a dubbing mode relating to at least one of a data format of a video stream dubbed to a second video recording unit composed of a removable recording medium and a dubbing time required for dubbing the video stream. A condition determining unit for determining a processing condition relating to a data format to be converted by the transcoder, and the transcoder according to a processing condition determined by the condition determining unit based on an input video stream dubbing request. Video stream converted through In the video dubbing apparatus for dubbing to the second video recording unit, the transcoder includes a transcoder having a plurality of processing structures with different processing loads, and the transcoder includes a transcoder having a plurality of processing structures. A switching control unit that switches and controls the processing structure is provided.

  Incidentally, as the processing load of the transcoder decreases, the processing speed, which is the speed of the data format conversion processing by the transcoder, increases, and as the processing load of the transcoder increases, the processing speed decreases.

In this regard, in the above configuration, for example, (a) a processing structure for converting the data format of the video stream at a higher speed as a transcoder.
(B) A processing structure for converting to a higher quality data format with less deterioration in image quality, frame rate, etc. even at a low processing speed.
As a transcoder, a transcoder having a plurality of processing structures with different processing loads (processing speeds) is provided. That is, according to such a transcoder having a plurality of processing structures that are specialized for the purpose of giving priority to processing speed or priority on image quality, the transcoder having only one processing structure is used. In addition, the options regarding the processing speed and the conversion mode of the data format of the video stream are greatly expanded. In this case, since the processing structure of such a transcoder is selectively switched by the switching control unit when performing the conversion process of the video stream data format, the processing speed and the conversion method of the video stream data format are described above. As a result, selection with a higher degree of freedom is possible with respect to the dubbing mode.

The plurality of processing structures having different processing loads include a first processing structure that includes a video stream resolution conversion process and a video stream resolution conversion process that does not include a video stream resolution conversion process. It is more practically desirable to include two processing structures.

  That is, in a transcoder having only a processing structure including resolution conversion processing, the video stream recorded in the first video recording unit is maintained at the resolution and the video stream is dubbed to the second video recording unit. Even in such a case, resolution conversion processing is performed because of the processing structure, and an increase in processing load as a transcoder is inevitable.

  In this regard, according to the above configuration, as the user instruction input signal, the resolution of the video stream recorded in the first video recording unit is maintained and the video stream is dubbed to the second video recording unit. When the signal is taken into the condition determination unit, the data stream conversion process of the video stream is performed through the second processing structure. In other words, the resolution conversion processing of the video stream itself is omitted, and the conversion processing of the data format is performed, and the dubbing mode with a higher degree of freedom can be selected through the reduction of the processing load on the transcoder.

  More specifically, as in the invention according to claim 3, the video stream is converted into a spatial frequency domain by transform coding processing, and a transform coefficient value obtained by the transform coding processing is converted into a quantization coefficient. Is recorded in the first video recording unit in a compressed state through at least three types of compression processing, namely, a quantization processing represented by: and a code allocation processing that assigns a variable-length code according to the appearance probability of the symbol, The first processing structure of the transcoder includes an inverse code assignment process for decompressing compressed data by the code assignment process, an inverse quantization process for decompressing compressed data by the quantization, and a compression by the transform coding process. A processing structure for performing at least three types of decompression processing with inverse transform coding processing for decompressing data, and at least three types of compression processing; The two processing structures include two types of decompression processing of the inverse code allocation processing and the inverse quantization processing of the three types of decompression processing, and the code allocation processing of the three types of compression processing; It includes at least one of a processing structure that performs two types of compression processing, that is, the quantization processing, and a processing structure that basically performs only a reduction in the bit rate of the video stream through extraction of a low-frequency term of the video stream. It is more practically desirable to realize the first and second processing structures.

Even in this case, the configuration of the transcoder itself is arbitrary. For example, according to the invention described in claim 4,
The transcoder includes a plurality of transcoder units having different processing structures, and the switching control unit selectively activates one of the plurality of transcoder units as the switching control.
Or, according to the invention as claimed in claim 5,
The transcoder is composed of a single transcoder in which the plurality of processing structures can be switched internally, and the switching control unit selectively switches the internal structure of the transcoder as the switching control.
It may be. However, in terms of avoiding a redundant configuration as a transcoder, it is more practically preferable to configure the transcoder from a single transcoder.

Further, in the invention according to any one of claims 1 to 5, as in the invention according to claim 6, the condition determination unit includes a processing structure of the transcoder and video stream data output from the transcoder. A processing speed that is the speed of the data format conversion processing itself by the transcoder for each conversion processing condition that is a combination with a format, and a process in which the acquired processing speed is associated with the conversion processing condition Creating the condition table, and taking the user instruction input signal instructing a dubbing mode related to at least one of a data format of the video stream to be dubbed into the second video recording unit and the dubbing time; Select one of the conversion processing conditions on the processing condition table with reference to the processing condition table If so the transcoder to determine processing conditions on the data format to be converted processed by, it is possible to easily realize the determination of the process conditions by such condition determining unit.

  Note that the processing speed is determined by the data format of the video stream input to the transcoder, the processing structure of the transcoder, and the data format of the video stream output from the transcoder.

  Further, in the invention according to claim 6, as in the invention according to claim 7, the image processing apparatus further includes a display control unit that controls display of an image on the display unit, and the condition determination unit is configured based on the created processing condition table. A plurality of assumed dubbing modes are displayed on the display unit through the display control unit, and when one of the dubbing modes displayed on the display unit is selected by the user, the selected dubbing mode is input to the user instruction If the signal is captured as a signal, one of a plurality of dubbing modes already assumed in the condition determination unit is captured as the user instruction input signal. Therefore, the transcoder performs a conversion process through the user instruction input signal. It becomes possible to more easily determine the processing conditions relating to the data format to be performed.

  Also, in the invention according to claim 7, as in the invention according to claim 8, the condition determination unit sets a writing speed, which is a speed at which data is written to a recording medium, to the second video recording. And the dubbing mode displayed on the display unit when calculating the dubbing time for each of the conversion processing conditions by comparing the acquired writing speed with the acquired processing speed. It is more practically desirable to include information on the calculated dubbing time.

  As the second video recording unit, it is more desirable to adopt a removable hard disk as in the ninth aspect of the invention. That is, as described above, the writing speed of such a hard disk is more than 1000 times the playback speed. Therefore, if the processing speed can follow the writing speed, the dubbing time can be selected. The width of will spread greatly. Accordingly, such a video dubbing apparatus that includes a transcoder having a plurality of processing structures with different processing loads and performs data format conversion processing by selectively switching the processing structure of the transcoder is provided with such a removable hard disk. Is particularly effective when employed as the second video recording unit.

  According to the present invention, it is possible to provide a video dubbing apparatus that enables selection of a dubbing mode with a higher degree of freedom without depending on a recording medium.

  Hereinafter, an embodiment of an image dubbing apparatus according to the present invention will be described in detail with reference to FIGS. The video dubbing apparatus according to this embodiment is assumed to be a video dubbing apparatus in which a removable hard disk recorder has a built-in hard disk drive for controlling the drive of an internal recording hard disk. FIG. 1 is a block diagram showing the overall configuration of this video dubbing apparatus.

As shown in FIG. 1, in this video dubbing apparatus, the first video recording unit 11 is composed of a hard disk and is a part that records a video stream as compressed data. When compressing the video stream, MPEG (Moving Picture E) is used.
xparts Group) technology, and specifically,
(C) DCT (Discrete Cosine Transform) processing (DCT) as transform coding processing for transforming data into the spatial frequency domain.
(2) A quantization process (Q) in which the value of the transform coefficient obtained by the DCT process (DCT) is represented by a quantization coefficient. (E) A code assignment process (VLE) for assigning a variable-length code according to the appearance probability of a symbol.
These three compression techniques are used.

  The distributor 12 is a part that takes in the video stream from the first video recording unit 11, distributes it to any one of first to third transcoder units 13 a to 13 c to be described later, and outputs it. is there.

  Further, the transcoder 13 includes first to third transcoder units 13a to 13c to which the data format of the video stream is converted using a transcoding technique, and the first to third transcoder units 13a to 13c. This is a part for converting the data format of the video stream distributed to any one of 13c.

  2 shows the processing structure of the first transcoder unit 13a, FIG. 3 shows the processing structure of the second transcoder unit 13b, and FIG. 4 shows the third transcoder unit. The processing structure of the unit 13c is shown as a block diagram. As is apparent from FIGS. 2 to 4, the first to third transcoder units 13 a to 13 c have processing structures with different processing loads as processing structures for converting the data format of the video stream. It has been adopted. Hereinafter, the processing structure and operation of the first to third transcoder units 13a to 13c will be described in detail with reference to FIGS.

  First, as shown in FIG. 2, in the first transcoder unit 13a, the frame skip unit 13a1 is a part that adjusts the frame rate of the video stream. The DCT coefficient cut block 13a2 is a part that cuts the DCT coefficient of the video stream based on a control signal from the VLD block 13a3, which will be described later, and transmits the video stream at a low bit rate. The VLD block 13a3 performs a reverse code allocation process (VLD) for decompressing the compressed data by the code allocation process (VLE), and sends a control signal for enabling or disabling the cut process by the DCT coefficient cut block 13a2. This is the output part.

  In such a processing structure of the first transcoder unit 13a, the video stream captured by the first transcoder unit 13a is first adjusted to a predetermined frame rate by the frame skip unit 13a1. After that, as will be described later, only the bit rate of the video stream is reduced by extracting the low frequency term of the video stream in the DCT coefficient cut block 13a2 and the VLD block 13a3. Accordingly, in the first transcoder unit 13a, the processing load associated with the video stream conversion process is low, and the video stream conversion process can be performed at high speed.

  Here, a method for reducing the bit rate of the video stream using the DCT coefficient cut block 13a2 and the VLD block 13a3 will be described.

That is, the video stream taken into the DCT coefficient cut block 13a2 is compressed data compressed through DCT processing (DCT) and quantization processing (Q). The data is distributed in terms. However, it is generally known that in such a video stream, most of the information such as pixel values is concentrated in the low frequency term, and if only the low frequency term of the video stream is extracted, the video stream The bit rate can be lowered. Therefore, the VLD block 13a3 outputs the control signal with only the high-frequency term of the video stream being effective for the DCT coefficient cut of the video stream by the DCT coefficient cut block 13a2. As a result, the DCT coefficient cut block 13a2 receives such a control signal and cuts only the high-frequency term of the video stream. In other words, the low-frequency term of the video stream is extracted. The bit rate of the video stream can be reduced.

  Here, the processing mode of the VLD block 13a3 will be described in more detail. First, the VLD block 13a3 captures the same video stream as the video stream captured in the DCT coefficient cut block 13a2. Next, the VLD block 13a3 executes decompression processing of the compressed data by code allocation processing (VLE) on the captured video stream, and recognizes the spatial frequency of the DCT coefficient of the video stream that becomes apparent. Then, it is determined whether or not the recognized spatial frequency level is a target of the cut processing by the DCT coefficient cut block 13a2, and a control signal for validating or invalidating the DCT coefficient cut is output based on the determination. To do. Specifically, when it is determined that the DCT coefficient of the video stream exceeds the predetermined spatial frequency reference level and is a high-frequency term, and is subject to cut processing by the DCT coefficient cut block 13a2. A control signal for enabling the cut processing is output. On the other hand, when it is determined that the DCT coefficient of the video stream is a low frequency term that is equal to or lower than a predetermined reference level of the spatial frequency and is not a target of the cut process by the DCT coefficient cut block 13a2, the cut process is invalidated. A control signal is output. In this VLD block 13a3, the rate at which the bit rate of the video stream is reduced by adjusting the reference level of the spatial frequency, which is a criterion for determining whether the DCT coefficient cut block 13a2 is valid or invalid. It is also possible to adjust.

  On the other hand, as shown in FIG. 3, in the second transcoder unit 13b, the frame skip unit 13b1 is a part that adjusts the frame rate of the video stream. The VLD block 13b2 is a part that performs reverse code allocation processing (VLD). The IQ block 13b3 is a part that performs an inverse quantization process (IQ) for decompressing the compressed data by the quantization process (Q). The Q block 13b4 is a part that performs the quantization process (Q), and the VLE block 13b5 is a part that performs the code allocation process (VLE). As is clear from FIG. 3, these processing blocks 13b2 to 13b5 are arranged in series in order from the input side.

  In such a processing structure of the second transcoder unit 13b, the video stream captured by the second transcoder unit 13b is first adjusted to a predetermined frame rate by the frame skip unit 13b1. Then, the video stream whose frame rate is adjusted by the frame skip unit 13b1 is sequentially taken into the VLD block 13b2 and further the IQ block 13b3, and each of these processing blocks 13b2 and 13b3 performs code allocation processing (VLE), Furthermore, each compressed data by the quantization process (Q) is sequentially decompressed. Thereafter, the video stream is taken into the Q block 13b4 in the second transcoder unit 13b, and the Q stream 13b4 performs quantization processing (Q ) Is performed. Next, the video stream is taken into the VLE block 13b5, encoded by the VLE block 13b5, and then transmitted from the second transcoder unit 13b.

Thus, in the second transcoder unit 13b, as the processing structure, a processing structure having only a minimum functional block for performing the quantization process (Q) in such a manner that the video stream is reduced in bit rate. Is adopted. Therefore, when lowering the bit rate of the video stream, the second transcoder unit 13b is used rather than the first transcoder unit 13a that cuts all information included in the high-frequency term of the video stream. In this way, deterioration of the image quality and the like accompanying the reduction in the bit rate of the video stream is suppressed. However, in terms of the processing load required for the video stream conversion process, the second transcoder unit 13b basically only lowers the bit rate of the video stream through the extraction of the low frequency term of the video stream. It is possible to reduce the processing load by using the first transcoder unit 13a.

  On the other hand, as shown in FIG. 4, in the third transcoder unit 13c, the frame skip unit 13c1 is a part that adjusts the frame rate of the video stream. Further, the third transcoder unit 13c, except for the frame skip unit 13c1, is largely a partial DP for decoding a video stream that is compressed data, and resolution conversion of the video stream decoded by the partial DP. A portion KP that performs processing and a portion EP that encodes a video stream whose resolution has been converted by the portion KP.

  Among these, in the partial DP for decoding, from the input side of the video stream, the VLD block 13c2 for performing the reverse code allocation process (VLD), the IQ block 13c3 for performing the inverse quantization process (IQ), and the DCT process (DCT) The IDCT block 13c4 for performing the inverse DCT process (IDCT) for decompressing the compressed data is arranged in series. The partial DP for decoding is further formed with a first buffer 13c5 that takes in the video stream decoded through the processing blocks 13c2 to 13c4 and stores it. On the output side of the first buffer 13c5, the video stream output from the IDCT block 13c4 is, for example, a P picture that forms an image predicted with reference to an I picture that can restore the image alone. In some cases, a path for adding the stored video stream to the same video stream is arranged. Further, in the partial DP for performing the decoding, the VLD block 13c2 generates a motion vector indicating a spatial deviation between the video stream such as the I picture previously captured and the video stream such as the P picture captured thereafter. It has a path for generating and outputting it to the first buffer 13c5.

  On the other hand, the partial KP that performs the resolution conversion process captures the motion vector generated by the resolution conversion unit 13c6 and the VLD block 13c2 of the partial DP that performs the decoding, and the resolution conversion unit 13c6 determines the resolution of the video stream. The reduction / enlargement processing unit 13c13 adjusts the amount of spatial deviation indicated by the captured motion vector by the amount converted. Note that the motion vector adjusted in this way by the reduction / enlargement processing unit 13c13 is output to the second buffer 13c12 of the partial EP to be described below.

  On the other hand, in the partial EP that performs the encoding, from the resolution conversion unit 13c6 side, the DCT block 13c7 that performs DCT processing (DCT), the Q block 13c8 that performs quantization processing (Q), and the code allocation processing (VLE) The VLE block 13c9 that performs the above is arranged in series. Further, the partial EP for performing the encoding includes an IQ block 13c10 that performs inverse quantization processing (IQ), an IDCT block 13c11 that performs inverse DCT processing (IDCT), and a second buffer 13c12 that stores a video stream. A feedback path arranged in series is further formed. On the output side of the second buffer 13c12, when the video stream output from the IDCT block 13c11 is the P picture, for example, the same video stream is stored in the second buffer 13c12. A route for adding the video streams is arranged. Further, on the output side of the second buffer 13c12, a path for subtracting the video stream stored in the second buffer 13c12 from the video stream output from the resolution converter 13c6 is also arranged. ing.

  In such a processing structure of the third transcoder unit 13c, the video stream captured by the third transcoder unit 13c is first adjusted to a predetermined frame rate by the frame skip unit 13c1, and then decoded. Part DP is taken in. The video stream is sequentially taken into the VLD block 13c2, the IQ block 13c3, and further the IDCT block 13c4 in the partial DP to be decoded. , The compressed data by the quantization process (Q) and further by the DCT process (DCT) are sequentially decompressed. Then, the video stream decoded through such processing is taken out from the portion DP to be decoded and then output to the portion KP that performs the resolution conversion processing. At this time, the video stream is also stored in the first buffer 13c5.

  However, when the video stream captured by the third transcoder unit 13c is the P picture, the motion vector is generated by the VLD block 13c2. This motion vector is output to the first buffer 13c5, and the video stream stored in the first buffer 13c5 is corrected based on the motion vector. The corrected video stream is added to the video stream output from the IDCT block 13c4. Through this addition, the video stream output from the IDCT block 13c4 is decoded (motion compensated), and the decoded video stream is extracted from the part DP to be decoded, and then the resolution conversion process is performed. Part KP is taken in.

  The resolution of the video stream captured in the partial KP for which the resolution conversion process is performed is converted as desired by the resolution conversion unit 13c6. Thereafter, the video stream is output to the part EP to be encoded. However, when the third transcoder unit 13c does not need to convert the resolution of the video stream, the resolution conversion unit 13c6 outputs a video stream whose resolution is maintained.

  In the partial EP to be encoded, the video stream is sequentially taken into the DCT block 13c7, the Q block 13c8, and further the VLE block 13c9, and DCT processing (DCT) and quantization processing (DCT) and quantization processing performed in these blocks 13c7 to 13c9 ( Q), and further compression is performed sequentially by a code allocation process (VLE). Then, the video stream encoded through such processing is extracted from the part EP to be encoded, that is, from the third transcoder unit 13c.

  At this time, the video stream output from the Q block 13c8 is also taken in the feedback path in which the IQ block 13c10, the IDCT block 13c11, and the second buffer 13c12 are arranged in series in this order. Among the video streams taken in the feedback path, the compressed data obtained by the quantization process (Q) and the DCT process (DCT) are sequentially decompressed by the IQ block 13c10 and the IDCT block 13c11. The video stream decoded in this way is stored in the second buffer 13c12.

However, when the video stream captured by the third transcoder unit 13c is the P picture, the motion vector is generated in the VLD block 13c2 of the partial DP to be decoded as described above. ing. This motion vector is output to the reduction / enlargement processing unit 13c13, and the motion vector is reduced / enlarged by the amount of the resolution converted by the resolution conversion unit 13c6. Then, the motion vector generated by the VLD block 13c2 through such processing is taken into the second buffer 13c12, and the video stream stored in the second buffer 13c12 is corrected based on the motion vector. Is given. Then, the video stream corrected based on the motion vector is subtracted from the video stream extracted from the resolution converter 13c6, and the corrected video stream is corrected from the video stream extracted from the IDCT block 13c11. Is added. Of these, the subtraction reduces the temporal redundancy of the video stream taken into the DCT block 13c7. Further, depending on the addition, the video stream output from the IDCT block 13c11 is decoded (motion compensation), and the decoded video stream is stored in the second buffer 13c12. .

  As described above, the third transcoder unit 13c generally employs a processing structure for performing video stream decoding processing, resolution conversion processing, and encoding processing. That is, the processing structure (FIGS. 2 and 3) of the first and second transcoder units 13a and 13b is a second processing structure that does not include the resolution conversion processing of the video stream. The processing structure of the transcoder unit 13c is a first processing structure including resolution conversion processing of a video stream. Accordingly, when the video stream resolution conversion process is performed as the video stream data format conversion process, the video stream resolution conversion process can be performed by using the third transcoder. Become. Also, in terms of quality such as the image quality of the video stream, this is more than the first transcoder unit 13a and the second transcoder unit 13b that cut all information included in the high-frequency term of the video stream. The use of the third transcoder unit 13c can further suppress the deterioration. However, in terms of the processing load required for the video stream conversion process, the first and the first transcoding units 13c do not perform the resolution conversion process, DCT process, IDCT process, or the like of the video stream. It is possible to reduce the processing load by using two transcoder units 13a and 13b.

  In this video dubbing apparatus, the write control unit 14 is a part that performs write control of the video stream output from the transcoder 13 to the second video recording unit 15 configured by a removable hard disk.

  In this video dubbing apparatus, the media attribute extraction unit 16 is a part that extracts the media attribute indicating the attribute of the second video recording unit 15 from the second video recording unit 15. This media attribute includes information on the writing speed of the second video recording unit 15 as well as information on the type and standard of the second video recording unit 15.

  In this video dubbing apparatus, the user instruction input unit 17 performs dubbing related to at least one of the data format of the video stream dubbed to the second video recording unit 15 and the dubbing time required for dubbing the video stream. This is a portion to which a user instruction input signal that indicates a mode is input. In addition, this user instruction | indication input part 17 inputs the dubbing aspect selected and determined by the user among the several dubbing aspects displayed on the display part 21 as said user instruction | indication input signal.

  In this video dubbing apparatus, the condition determination unit 18 is a part for determining the processing condition relating to the data format to be converted by the transcoder 13, that is, the condition of the transcoding process. Specifically, the condition determination unit 18 takes in a user instruction input signal from the user instruction input unit 17 and determines the condition of the transcoding process based on the dubbing mode specified by the user instruction input signal. To do.

Note that the condition determination unit 18 of this embodiment is also configured as a part (for example, a microcomputer or the like) that performs overall control of control by the control unit 22 described later, control by the display control unit 20, and the like. Specifically, the condition determination unit 18 notifies the control unit 22 of the determined transcoding processing condition, and manages the video stream distribution processing by the distributor 12 through the control unit 22. Further, the condition determination unit 18 acquires a writing speed, which is a speed at which data is written to the recording medium, with respect to the second video recording unit 15, and converts the writing speed and the data format by the transcoder 13. A plurality of dubbing modes assumed from the processing speed, which is the speed of the processing itself, are displayed on the display unit 21 through the display control unit 20 described below. The writing speed is acquired from the media attribute extracted by the media attribute extraction unit 16. The processing speed is obtained through reference to a table stored in a transcoder performance table memory 19 described later.

  The display control unit 20 is a part that performs display control for displaying an image on the display unit 21.

  The control unit 22 is a part for controlling the video stream distribution processing by the distributor 12. The distribution process is controlled based on the video stream transcoding process conditions determined by the condition determining unit 18. That is, in this embodiment, the control unit 22 and the distributor 12 constitute a switching control unit.

  Next, in such a video dubbing apparatus, when a dubbing request for dubbing a video stream recorded in the first video recording unit 11 to the second video recording unit 15 is input. The operation of the video dubbing apparatus will be described with reference to FIG. However, each process executed by the condition determining unit 18 will be described with reference to FIG. FIG. 5 is a flowchart showing an example of the procedure of each process executed by the condition determining unit 18.

  In such a case, in the video dubbing apparatus, first, the media attribute extraction unit 16 extracts the media attribute from the second video recording unit 15 and outputs the extracted media attribute to the condition determination unit 18. .

  On the other hand, the condition determination unit 18 acquires the media attribute from the media attribute extraction unit 16 as the processing of step S1, and information such as the standard of the second video recording unit 15 and the writing speed thereof from the acquired media attribute. To get. In this embodiment, the standard of the second video recording unit 15 is a removable hard disk standard, and the writing speed thereof is about 1000 times the playback speed of the video stream. And so on. In step S2, the condition determination unit 18 acquires a video list of video streams recorded in the first video recording unit 11. The first video recording unit 11 of this embodiment includes “professional baseball”, “quiz”, “7 o'clock news”, “shogi”, “golf”, “volleyball”, and “professional baseball”. It is assumed that a video stream is recorded, and information regarding broadcast date / time, recording time, and channel is acquired as the video list for each title.

  Then, as a process of step S3, the condition determination unit 18 displays the acquired video list on the display unit 21 through the display control unit 20 as a guidance screen illustrated in FIG. In this guidance screen, a small screen for displaying a still image is displayed in the guidance screen, and the representative screen of the title selected and highlighted in the video list is the small screen. It is supposed to be reduced and displayed as a still image. The still image is displayed on the display unit 21 through the display control unit 20 when the video stream (program) recorded in the first video recording unit 11 is taken into the condition determination unit 18. Incidentally, the guidance screen may be, for example, a screen displaying thumbnails of representative screens for each program recorded in the first video recording unit 11.

Then, based on the fact that an arbitrary title is selected and determined by the user from the video list displayed on the display unit 21, the video dubbing apparatus uses the video stream of the selected program as the second video stream. Each process for dubbing to the video recording unit 15 is performed as follows. Note that the selection and determination by the user are performed through, for example, an operation switch provided in the video dubbing apparatus body or an operation by a remote controller.

  That is, in this case, an instruction signal for reading the video stream of the title selected by the user from the first video recording unit 11 and dubbing it to the second video recording unit 15 is sent to the user instruction input unit 17. Entered.

  On the other hand, the condition determination unit 18 inputs the instruction signal from the user instruction input unit 17 as the process of step S4. In step S5, information about the data format of the video stream selected by the user from the video streams recorded in the first video recording unit 11 and dubbed later is acquired. Note that the data format of the video stream includes information on the bit rate (input bit rate) and resolution (input resolution). Thereafter, as a process in step S6, a table stored in the transcoder performance table memory 19 is referred to.

Here, the table stored in the transcoder performance table memory 19 will be specifically described. As shown in FIG. 7, the transcoder performance table memory 19 stores a transcoder performance table 19a indicating the characteristics of the first to third transcoder units 13a to 13c. That is, the transcoder performance table 19a includes, for example,
(F) Input resolution “720 × 480”.
(G) Input bit rate “10 Mbps”.
Of the video stream at the first transcoder unit 13a.
(H) Resolution (output resolution) “720 × 480”.
(Li) Bit rate (output bit rate) “8 Mbps”.
The video stream having an image quality of “38 dB” is output from the transcoder 13, and the processing speed of the transcoder 13 is 120 times the playback speed of the video stream.
(Nu) Input resolution “720 × 480”.
(L) Input bit rate “10 Mbps”.
Is transmitted by the third transcoder unit 13c.
(E) Output resolution “720 × 480”.
(W) Output bit rate “8 Mbps”.
When the video stream is converted to a video stream, a video stream with an image quality of “46 dB” is output from the transcoder 13, the processing speed of the transcoder 13 is six times the playback speed of the video stream, and so on. It is shown. Information regarding the second transcoder unit 13b is also stored in the transcoder performance table 19a, but is not shown here for convenience.

As is apparent from the transcoder performance table 19a, in such a transcoder 13 having the above-described first to third transcoder units 13a to 13c, the writing speed of the removable hard disk is almost “1000 × speed”. On the other hand, the processing speed is “6 × speed” to “1220 × speed”. Also, it can be seen that there are a wide range of options regarding the conversion mode of the data format of the video stream such that the image quality of the video stream output from the transcoder 13 is also “32 dB” to “46 dB”. Accordingly, in performing the conversion process of the data format of the video stream, the first to third transcoder units 13a to 13c are controlled so as to change the data format of the video stream.
As a result, with respect to the dubbing mode, selection with a higher degree of freedom is possible without depending on the writing speed of the second video recording unit 15.

  In the process of step S6, the condition determination unit 18 refers to such a transcoder performance table 19a and extracts only necessary information from the information listed on the transcoder performance table 19a. . That is, among the information listed on the transcoder performance table 19a, for information specifying a data format different from the input bit rate and input resolution of the video stream selected by the user, the processing mode of the video stream, and consequently It cannot be one of the options for dubbing. Accordingly, in the process of step S6, the input bit rate and the input resolution that are the same as the input bit rate and the input resolution of the video stream selected by the user are specified from the information listed on the transcoder performance table 19a. Only the information to be extracted.

  Based on the extracted information, as a process of step S7, the condition determination unit 18 creates a process condition table 19b illustrated in FIG. 8 and stores the created process condition table 19b in the transcoder performance table memory 19. Store in a predetermined temporary memory (RAM or the like).

  In this processing condition table 19b, the processing mode of the video stream assumed from the extracted information is shown. Specifically, the processing structure of the transcoder 13 and the data of the video stream output from the transcoder 13 are shown. A conversion processing condition that is a combination with a format is shown in association with a processing time that is a time required for the conversion processing. That is, any of the processing modes listed on the processing condition table 19b is selected later, and the video stream conversion processing by the transcoder 13 is performed. The processing time is calculated from the recording time (recording time) of the video stream acquired as the video list and the processing speed of the transcoder 13.

  Incidentally, in this processing condition table 19b, the data format of the video stream output from the transcoder 13 is evaluated in three stages: a file capacity indicating the data amount of the video stream, and “low”, “medium”, and “high”. The image quality is indicated by the quality of the image, and the user can easily select the data format of the video stream. Of these, the file capacity includes the file size of the video stream input to the transcoder 13, the bit rate (input bit rate) of the video stream, and the bit rate (output bit) of the video stream output from the transcoder 13. Rate). Regarding the image quality, for example, when the first and second threshold values are provided at “35 dB” and “40 dB”, respectively, and the above evaluation is performed through comparison between these threshold values and the image quality of the video stream output from the transcoder 13. can do.

  Then, as the process of step S8, the condition determining unit 18 displays a plurality of dubbing modes assumed from the processing condition table 19b on the display unit 21 through the display control unit 20 as a guidance screen illustrated in FIG. indicate. Here, a plurality of dubbing modes are assumed depending on the combination of the image quality of the video stream, its file size, and the dubbing time that is the time required for dubbing.

That is, the condition determination unit 18 of this embodiment compares the acquired writing speed of the second video recording unit 15 with the processing speed (processing time) indicated in the processing condition table 19b, and The dubbing time for each conversion processing condition is calculated, and information relating to the dubbing time is included in the dubbing mode displayed on the display unit 21. As described above, the dubbing time is determined based on the slower speed of the writing speed and the processing speed. Of the dubbing modes displayed in the guidance screen, the item “perfect” with respect to the file size is dubbing for converting the file size of the video stream to a capacity approximately equal to the remaining capacity of the second video recording unit 15. It refers to an embodiment. Incidentally, even in the guidance screen illustrated in FIG. 9, the dubbing mode selected through the operation by the remote controller or the like is highlighted as in the guidance screen illustrated in FIG.

  When one of a plurality of dubbing modes displayed on the guide screen is selected and determined by the user, a user instruction input signal for dubbing the video stream in the selected dubbing mode is received by the user. The instruction is input to the instruction input unit 17.

  On the other hand, the condition determination unit 18 takes in the user instruction input signal from the user instruction input unit 17 as the process of step S9. Next, as the processing in step S10, the processing condition relating to the data format to be converted by the transcoder 13 is determined based on the captured user instruction input signal.

  In this determination, the condition determination unit 18 reads the created processing condition table 19b from the temporary memory in the transcoder performance table memory 19 and refers to it. Then, the condition of the transcoding process is determined by selecting a conversion process condition that satisfies the condition of the dubbing mode indicated by the user instruction input signal from the processing modes on the processing condition table 19b. That is, in this embodiment, the plurality of dubbing modes displayed on the display unit 21 are the modes assumed from the created processing condition table 19b, and the user selects one of the plurality of dubbing modes. This mode is taken into the condition determination unit 18 as a user instruction input signal. Therefore, by referring to the created processing condition table 19b, it is possible to more easily determine the conditions of the transcoding process for realizing the selected dubbing mode.

  When the processing conditions relating to the data format to be converted are determined in this way, the condition determining unit 18 determines the file capacity, image quality, and processing time conditions specified in the selected conversion processing conditions. Notify the control unit 22.

  The control unit 22 determines which of the transcoder units 13a to 13c should perform the video stream transcoding processing based on the conditions notified from the condition determination unit 18. Based on this determination, the control unit 22 controls the distribution process of the video stream by the distributor 12, so that the video stream stored in the first video recording unit 11 passes through the distributor 12. The data is distributed to the transcoder unit determined by the control unit 22. The video stream is subjected to the transcoding process in the transcoder 13 under the conditions of the video stream transcoding process determined by the condition determination unit 18. Then, the video stream thus transcoded is dubbed to the second video recording unit 15 through the write control unit 14 in a dubbing manner selected by the user.

  As described above, according to the video dubbing apparatus according to this embodiment, excellent effects as described below can be obtained.

  (1) The transcoder 13 includes first to third transcoder units 13a to 13c having a plurality of processing structures having different processing loads. For this reason, options regarding the processing speed and the conversion method of the data format of the video stream are greatly expanded as compared with a transcoder having only one processing structure. And in performing the conversion processing of the data format of the video stream, the transcoder units 13a to 13c are selectively switched, so that the processing speed and the conversion method of the data format of the video stream, and thus the dubbing mode are as follows. Selection with a higher degree of freedom becomes possible.

  (2) As a plurality of processing structures having different processing loads, a third transcoder unit 13c including a video stream resolution conversion process, and a first and second transcoder unit 13a including no video stream resolution conversion process, 13b. For this reason, it becomes possible to select a dubbing mode with a higher degree of freedom through reduction of the processing load of the transcoder.

  (3) The condition determination unit 18 creates the processing condition table 19b in which the processing speed is associated with the conversion processing condition. When the dubbing mode is designated, the processing condition relating to the data format to be converted by the transcoder is selected by referring to the created processing condition table 19b and selecting one of the conversion processing conditions on the table 19b. Judgment was made. For this reason, determination of the processing conditions by the condition determination unit 18 can be easily realized.

  (4) The condition determination unit 18 displays a plurality of dubbing modes assumed from the created processing condition table 19b on the display unit 21 through the display control unit 20, and one of the displayed dubbing modes is selected by the user. The selected dubbing mode is captured as the user instruction input signal. As a result, one of a plurality of dubbing modes already assumed in the condition determining unit 18 is captured as the user instruction input signal. Therefore, the data to be converted by the transcoder 13 through the user instruction input signal. It becomes possible to more easily determine the processing conditions related to the format.

  In addition, the said embodiment can also be changed and implemented as follows.

  A plurality of dubbing modes are assumed from the processing condition table 19b according to the combination of the use of the second video recording unit 15, the file size of the video stream, the dubbing time, and the resolution. You may make it display on the display part 21 as a guidance screen illustrated in FIG. Of these, the use of the second video recording unit 15 is a parameter indicating the quality of the video stream. That is, when library storage (long-term storage) is selected, the video stream is converted into high image quality by the transcoder 13, and when temporal storage (short-term storage) is selected, The transcoder 13 converts the video stream to low image quality. In addition, regarding the usage of the second video recording unit 15, even if it is not selected by the user, it may be extracted from the second video recording unit 15 to the media attribute extraction unit 16 as the media attribute. Good. In such a case, the quality of the dubbed image is determined according to the standard of the second video recording unit 15. Incidentally, when the user selects and determines a resolution different from the resolution of the video stream recorded in the first video recording unit 11 on the guidance screen illustrated in FIG. 10, the condition determination unit 18 performs the resolution conversion process. It is determined that the data format conversion processing is performed using the third transcoder unit 13c having the above function.

  It is arbitrary how the dubbing mode assumed from the processing condition table 19b is displayed on the display unit 21. For example, the time when dubbing ends may be displayed as the information related to the dubbing time, or the information related to the dubbing time may be omitted.

  The condition determination unit 18 may store a plurality of dubbing modes in a predetermined memory in advance, and display the plurality of dubbing modes read from the memory on the display unit 21. In this case, the same plurality of dubbing modes are always displayed as the guidance screen regardless of the bit rate or resolution of the video stream recorded in the first video recording unit 11.

The condition determining unit 18 does not create the processing condition table 19b, and determines the condition of the transcoding process with reference to the transcoder performance table 19a based on the user instruction input signal fetched from the user instruction input unit 17. It may be a thing.

-Instead of the transcoder performance table 19a, the image quality of the video stream output from the first transcoder unit 13a and the processing speed thereof are as follows:

Qu1 = C1 * Rx + C2 * Bi + C3 * Bo (1)
Sp = C4 × Rx + C5 × Bi + C6 × Bo (2)
However,
Qu1: Image quality of the video stream output from the transcoder 13
Sp: Processing speed of transcoder 13
Rx: Normalized value of input resolution in the horizontal direction (standardized to be in the range of “0” to “1”)
Bi: Input bit rate normalized value
Bo: normalized value of output bit rate C1 to C6: weighting factors for weighting parameters Rx, Bi, Bo

It may be specified based on the approximate relational expression. The relational expression between the image quality and the bit rate is known to be obtained from the rate-distortion relation, but in this example, the approximate expression (1) is used. The same applies to the image quality of the video stream output from the third transcoder unit 13c and the processing speed thereof.

Qu2 = C7 * R + C8 * Bi + C9 * Bo (3)
Sp = C10 × R + C11 × Bi + C12 × Bo (4)
However,
Qu2: Image quality of the video stream output from the transcoder 13
Sp: Processing speed of transcoder 13
R: Normalized value of ratio between input resolution and output resolution in the horizontal direction C7 to C12: Weighting factors for weighting each parameter R, Bi, Bo

It may be specified based on the approximate relational expression. Note that the image quality of the video stream output from the second transcoder unit 13b and the processing speed thereof can be similarly specified based on the approximate relational expression.

  The configuration of the transcoder 13 itself is arbitrary. However, in order to avoid a redundant configuration as the transcoder 13, unlike the transcoder 13 of the above-described embodiment, it is more practically preferable to configure the transcoder 13 from one transcoder 13. Specifically, a single transcoder in which a plurality of processing structures can be switched internally is adopted as the transcoder 13, and the internal structure is selectively switched. For example, as shown in FIGS. 11 to 13, as the processing structure of the transcoder 13, the output of the frame skip unit 13c1 is taken in parallel with the VLD block 13c2 into the processing structure of the third transcoder unit 13c. A processing structure to which the DCT coefficient cut block 13c20 is added is adopted. In the processing structure of the transcoder 13, switch means for switching the validity or invalidity of these functions is provided for each processing block. The configuration and operation of the DCT coefficient cut block 13c20 are the same as those of the DCT coefficient cut block 13a2 of the first transcoder unit 13a.

In such a processing structure of the transcoder 13, the processing structures of the first to third transcoder units 13a to 13c can be realized through switching by the switch means. For example, as shown in FIG. 11, if only the functions of the frame skip unit 13c1, the VLD block 13c2, and the DCT coefficient cut block 13c20 are enabled through the switching by the switch means, the first transcoder 13 is connected to the first transcoder 13. The same processing structure as that of the transcoder unit 13a appears. In this case, the VLD block 13c2 performs a reverse code assignment process (VLD) and outputs a control signal for validating or invalidating the cut process by the DCT coefficient cut block 13c20. Also, for example, as shown in FIG. 12, if only the functions of the processing blocks 13c1 to 13c3, 13c8, and 13c9 are enabled through switching by the switch means, the second transcoder unit is added to the transcoder 13. The same processing structure as 13b appears. Also, for example, as shown in FIG. 13, if only the function of the DCT coefficient cut block 13c20 is disabled through switching by the switch means, the same processing structure as that of the third transcoder unit 13c is provided in the transcoder 13. Will appear.

  The compression technique used for the video stream recorded in the first video recording unit 11 and the mode of compression are not limited. However, when the video stream compression technique is changed, the processing structure of the transcoder 13 is also changed in accordance with the change.

  If the transcoder 13 is provided with a plurality of processing structures having different processing loads, and the video stream data format conversion process is performed by selectively switching these processing structures, at least the effect (1) can be obtained. Can get.

  As the second video recording unit 15, a DVD standard optical disc or a plurality of recording media may be adopted. However, in view of the fact that the writing speed of the removable hard disk is more than 1000 times the playback speed, in such a video dubbing apparatus, the removable hard disk is particularly effective when used as the second video recording unit. It is.

1 is a block diagram showing the overall configuration of an embodiment of a video dubbing apparatus according to the present invention. The block diagram which shows the processing structure of a 1st transcoder part. The block diagram which shows the processing structure of a 2nd transcoder part. The block diagram which shows the processing structure of a 3rd transcoder part. The flowchart which shows the procedure of the process about judgment of the conditions of the transcoding process by a condition judgment part. The figure which shows the image | video list displayed as a guidance screen on a display part. Table stored in transcoder performance table memory. A processing condition table created by the condition determination unit. The figure which shows the some dubbing aspect displayed as a guidance screen on a display part. The figure which shows another example of the some dubbing aspect displayed as a guidance screen on a display part. The block diagram which shows another example of the processing structure of a transcoder. The block diagram which shows another example of the processing structure of a transcoder. The block diagram which shows another example of the processing structure of a transcoder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... 1st video recording part, 12 ... Distributor, 13 ... Transcoder, 13a ... 1st transcoder part, 13b ... 2nd transcoder part, 13c ... 3rd transcoder part, 13a1 ... Frame skip 13a2 ... DCT coefficient cut block, 13a3 ... VLD block, 13b1 ... frame skip unit, 13b2 ... VLD block, 13b3 ... IQ block, 13b4 ... Q block, 13b5 ... VLE block, 13c1 ... frame skip unit, 13c2 ... VLD block 13c3 ... IQ block, 13c4 ... IDCT block, 13c5 ... first buffer, 13c6 ... resolution converter, 13c7 ... DCT block, 13c8 ... Q block, 13c9 ... VLE block, 13c10 ... IQ block, 13c11 ... IDCT block, 1 c12 ... second buffer, 13c13 ... reduction / enlargement processing unit, 13c20 ... DCT coefficient cut block, 14 ... write control unit, 15 ... second video recording unit, 16 ... media attribute extraction unit, 17 ... user instruction input unit , 18 ... Condition determining unit, 19 ... Transcoder performance table memory, 19a ... Transcoder performance table, 19b ... Processing condition table, 20 ... Display control unit, 21 ... Display unit, 22 ... Control unit.

Claims (8)

A transcoder that converts the data format of a video stream that is read from the first video recording unit in which the video stream is recorded as compressed data, and a video stream that is dubbed to the second video recording unit that includes a removable recording medium Condition determination for determining a processing condition relating to a data format to be converted by the transcoder based on a user instruction input signal that indicates a dubbing mode relating to at least one of the data format and dubbing time required for dubbing the video stream A video stream that is converted through the transcoder in accordance with processing conditions determined by the condition determination unit based on a dubbing request for the input video stream, and dubbing the second video recording unit In video dubbing equipment,
The transcoder has a plurality of processing structures with different processing loads, and further includes a switching control unit that switches and controls the processing structure of the transcoder based on the determination by the condition determination unit,
The condition determination unit is the speed of the data format conversion processing itself by the transcoder for each conversion processing condition that is a combination of the processing structure of the transcoder and the data format of the video stream output from the transcoder. The processing speed is acquired, a processing condition table in which the acquired processing speed is associated with the conversion processing condition is created, and the data format of the video stream dubbed to the second video recording unit and the dubbing By referring to the created processing condition table and selecting one of the conversion processing conditions on the processing condition table based on the user instruction input signal instructing the dubbing mode relating to at least one of the times, Determine the processing conditions related to the data format to be transcoded by the transcoder Video dubbing apparatus, characterized in that.   The transcoder has, as a plurality of processing structures having different processing loads, a first processing structure including resolution conversion processing of the video stream and a second processing structure not including resolution conversion processing of the video stream. The video dubbing apparatus according to claim 1, which is a device.   The video stream includes a transform coding process for transforming data into a spatial frequency domain, a quantization process for representing a transform coefficient value obtained by the transform coding process with a quantization coefficient, and a variable length code according to a symbol appearance probability. Is recorded in the first video recording unit in a compressed state through at least three types of compression processing and a code allocation processing for allocating the code, and the first processing structure of the transcoder includes the code allocation processing. At least three types of decompression processes: an inverse code assignment process for decompressing compressed data, an inverse quantization process for decompressing compressed data by quantization, and an inverse transform encoding process for decompressing compressed data by the transform encoding process , And a processing structure for performing at least three types of compression processing, and the second processing structure of the transcoder includes the inverse of the three types of decompression processing. A processing structure for performing two types of compression processing of the code allocation processing and the quantization processing among the two types of decompression processing of the signal allocation processing and the inverse quantization processing, and the three types of compression processing; 3. The video dubbing apparatus according to claim 2, comprising at least one of a processing structure that basically performs only a low bit rate reduction of the video stream through extraction of a low-frequency term of the video stream.   3. The transcoder includes a plurality of transcoder units having different processing structures, and the switching control unit selectively activates one of the plurality of transcoder units as the switching control. Or the video dubbing apparatus according to 3.   The transcoder includes a single transcoder in which the plurality of processing structures can be switched internally, and the switching control unit selectively switches the internal structure of the transcoder as the switching control. Item 4. The video dubbing apparatus according to Item 2 or 3. The video dubbing device according to claim 1 ,
The display control unit further includes a display control unit that controls display of an image on the display unit, and the condition determination unit displays a plurality of dubbing modes assumed from the created processing condition table on the display unit through the display control unit, and When one of the dubbing modes displayed on the display unit is selected by the user, the selected dubbing mode is captured as the user instruction input signal. The condition determining unit acquires a writing speed, which is a speed at which data is written to the recording medium, from the second video recording unit, and compares the acquired writing speed with the acquired processing speed. The video dubbing apparatus according to claim 6 , wherein the dubbing time for each conversion processing condition is calculated, and the dubbing mode displayed on the display unit includes information on the calculated dubbing time. The video dubbing apparatus according to claim 1 , wherein the second video recording unit includes a removable hard disk.

Images