JP2014132730A - Sync information generation device and program thereof, and sync data reproduction device and program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of synchronizing a plurality of signals.SOLUTION: A signal synchronization system 1 comprises: a transmitting device 2 provided with encoding means 21 for sequentially generating encoded data per prescribed signal interval of an input signal, and sync information generation means 22 provided with hash value calculation means 222 for calculating a generation-side hash value with regard to a local decode signal in a prescribed signal interval of the input signal, and multiplexing means 223 for sequentially generating multiplexed data (sync information) composed of the generation-side hash value and data synchronized to the prescribed signal interval of the input signal; and a receiving device 3 provided with decoding means 31 for decoding a local decode signal from the encoded data, and sync data reproduction means 32 provided with hash value calculation means 321 for generating a reproduction-side hash value with regard to the local decode signal, and hash value collation means 323 for sequentially collating the reproduction-side hash value and the generation-side hash value included in a sync information data row and searching for data linked to the generation-side hash value taking on the same value as the reproduction-side hash value.

Description

  The present invention relates to a technique for synchronizing a plurality of signals.

Conventionally, in order to perform signal synchronization, a synchronization signal is superimposed on a modulation signal (a ternary synchronization signal, a black burst signal, or the like).
In addition, time information is embedded in a modulated video signal (VITC: Vertical Interval Timecode) and time information is expressed by an audio signal (LTC: Longitudinal Timecode). Furthermore, there is a method in which time information can be embedded in the digital signal together with the original signal (for example, SDI: Serial Digital Interface).
When a video signal and an audio signal are encoded and transmitted, a synchronization signal based on the system clock of the encoding device is added to both the video and audio and multiplexed and transmitted, so that the video and audio are transmitted on the receiving side. An apparatus for detecting a time difference and achieving synchronization is disclosed (see Patent Document 1).

Japanese Patent No. 3633972

  However, in the case of a conventional synchronization signal, for example, in the case of a video synchronization signal, it is possible to know the switching timing of the frame, field, or line on the receiving side, but the absolute time position of the frame (or field) ( For example, the frame number counted from the beginning of the video) could not be specified.

  According to the time code information of VITC, LTC, and SDI described above, it is possible to know the absolute time position. However, since these time code information is transmitted on a channel different from the original signal (video signal or audio signal) or embedded in another recording area (for example, a blanking period), the image code The time code information may be lost when passing through the transmission apparatus, transmission apparatus, or other signal processing equipment.

  As a result, when information such as video, audio, and data is transmitted, it is difficult to synchronize information at the reception point, and for example, there is a problem that synchronization between video and audio (lip sync) is shifted. When various information (ES: Elementary Stream) is multiplexed only by a predetermined method as in TS (Transport Stream), it is not impossible to maintain synchronization, but for example, TS is once demultiplexed. If various types of information are transmitted / stored by other means after the conversion, synchronization between the information becomes difficult.

  The device described in Patent Document 1 described above needs to add a synchronization signal to both video and audio before multiplexing the compressed video and audio signals on the transmission side. For this reason, for example, when there is no empty area in either one of video and audio and a synchronization signal cannot be added, signal synchronization becomes impossible.

  Therefore, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technique capable of synchronizing a plurality of signals.

  The invention according to claim 1, which was created to solve the above-mentioned problem, synchronizes data synchronized with a predetermined signal section of an input signal with a signal corresponding to the predetermined signal section of the input signal on the reproduction side. A synchronization information generation apparatus that generates synchronization information for reproduction, and includes a decoding unit, a generation-side hash value calculation unit, and a multiplexing unit.

  According to such a configuration, the synchronization information generating apparatus receives the encoded data of the input signal by the decoding unit, and sequentially decodes the signal corresponding to the predetermined signal section of the input signal from the encoded data. Examples of the input signal include a video signal and an audio signal. The signal corresponding to the predetermined signal section of the input signal thus obtained is the same information as the signal obtained by decoding the encoded data of the predetermined signal section of the input signal on the reproduction side.

  In addition, the synchronization information generation apparatus calculates a generation-side hash value using a predetermined hash function for the signal decoded by the decoding unit by the generation-side hash value calculation unit. Here, the generation-side hash value is information representing the feature amount of the signal corresponding to the predetermined signal section of the input signal decoded by the decoding unit.

  Further, the synchronization information generation device generates multiplexed data of the generation side hash value calculated by the generation side hash value calculation unit and data synchronized with a predetermined signal section of the input signal as synchronization information by the multiplexing unit. Output sequentially. As a result, the data synchronized with the predetermined signal section of the input signal and the generation hash value generated for the signal corresponding to the predetermined signal section of the input signal can be linked. Examples of data synchronized with a predetermined signal section of the input signal include time information and data other than time information. As a result, on the reproduction side, it is possible to specify data synchronized with a predetermined signal section of the input signal from the data string of the synchronization information based on the generation-side hash value.

  The invention according to claim 2 generates synchronization information for reproducing data synchronized with a predetermined signal section of the input signal in synchronization with a signal corresponding to the predetermined signal section of the input signal on the reproduction side. The synchronization information generating apparatus includes a generation-side hash value calculation unit and a multiplexing unit.

According to such a configuration, the synchronization information generation apparatus calculates the generation-side hash value using a predetermined hash function for the predetermined signal section of the input signal by the generation-side hash value calculation means. Examples of the input signal include a video signal and an audio signal. The generation-side hash value is information that represents a feature amount of a predetermined signal section of an input signal to the synchronization information generation device.
Here, the predetermined signal section of the input signal input to the generation side and the signal corresponding to the predetermined signal section of the input signal reproduced on the reproduction side are the same information.

  In addition, the synchronization information generation device generates, as synchronization information, multiplexed data of the generation-side hash value calculated by the generation-side hash value calculation unit and data synchronized with a predetermined signal section of the input signal by the multiplexing unit. Output sequentially. As a result, the data synchronized with the predetermined signal section of the input signal and the generation-side hash value generated for the predetermined signal section of the input signal can be linked. Examples of data synchronized with a predetermined signal section of the input signal include time information and data other than time information. As a result, on the reproduction side, it is possible to specify data synchronized with a predetermined signal section of the input signal from the data string of the synchronization information based on the generation-side hash value.

  According to a third aspect of the present invention, there is provided synchronization information that is multiplexed data of a generator-side hash value generated corresponding to a predetermined signal section of an input signal and data synchronized with the predetermined signal section of the input signal. A synchronous data reproduction device that sequentially inputs and reproduces data synchronized with a predetermined signal section of an input signal based on this synchronization information, comprising: a reproduction-side hash value calculation means; and a hash value collation means Features.

According to such a configuration, the synchronous data reproduction device sequentially inputs signals corresponding to the predetermined signal section of the input signal decoded from the encoded data of the input signal by the reproduction-side hash value calculation means, and the decoded signal On the other hand, the reproduction-side hash value is calculated using the same hash function as the hash function used to calculate the generation-side hash value. The reproduction-side hash value is information that represents a feature amount of a signal corresponding to a predetermined signal section of the input signal. As a result, a reproduction-side hash value that can be collated with the generation-side hash value generated for the signal corresponding to the predetermined signal section of the input signal is obtained. The generation-side hash value may be generated from the predetermined signal section of the input signal itself, or may be generated from a signal decoded from the encoded data of the predetermined signal section of the input signal.
Further, the synchronization data reproducing apparatus sequentially reproduces the hash value collating unit by comparing the reproduction-side hash value calculated by the reproduction-side hash value calculating unit with the generation-side hash value included in the data string of the synchronization information. Search for data associated with the generator hash value that has the same value as the side hash value.

  As described above, the synchronization data reproducing device associates the reproduction-side hash value with the generation-side hash value by the hash value collating unit, so that the synchronization signal data string is generated in the predetermined signal section of the input signal from the synchronization information data string. Synchronized data can be specified. In this way, the synchronous data reproducing apparatus can link the predetermined signal section of the input signal with the data synchronized with the predetermined signal section of the input signal.

  According to a fourth aspect of the present invention, in the synchronous data reproducing device according to the third aspect, the hash value collating means has the same arrangement as a certain reproduction side hash value and a bundle of the reproduction side hash values before and after the reproduction side hash value. A plurality of the generator hash values included in the generator hash value bundle, which is searched from the synchronization information data string and has the same array as the reproduction hash value bundle. And searching for the data associated with each.

  According to such a configuration, the synchronous data reproducing device uses a certain reproduction-side hash value and a reproduction-side hash value before and after the reproduction-side hash value as a bundle, and generates a bundle of generation-side hash values that have the same array as the bundle. The error rate can be reduced by searching and matching the data sequence of the synchronization information. Therefore, the synchronous data reproducing device can accurately specify the data associated with each of the plurality of generation-side hash values included in the generation-side hash value bundle having the same array as the reproduction-side hash value bundle.

  The invention described in claim 5 is a synchronization information generating program for causing a computer to function as the synchronization information generating apparatus described in claim 1 or 2.

  A sixth aspect of the present invention is a synchronous data reproduction program for causing a computer to function as the synchronous data reproduction device according to the third or fourth aspect.

According to the first, second, and fifth aspects of the present invention, the reproduction side specifies data synchronized with a predetermined signal section of the input signal without adding synchronization information to the input signal that is one of the transmission target signals. can do. Therefore, on the reproduction side, this data can be reproduced in synchronization with a predetermined signal section of the input signal.
According to the third and sixth aspects of the present invention, the data synchronized with the predetermined signal section of the input signal is specified from the synchronization information data string by associating the generation-side hash value with the reproduction-side hash value. can do. Therefore, this data can be reproduced in synchronization with a predetermined signal section of the input signal.
According to the fourth aspect of the present invention, it is possible to more accurately specify data synchronized with a predetermined signal section of the input signal.

It is a block diagram for demonstrating the structure of the signal synchronization system which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating operation | movement of the transmitter of the signal synchronization system which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating operation | movement of the receiver of the signal synchronization system which concerns on embodiment of this invention. It is a conceptual diagram for demonstrating the mode of collation with the production | generation side hash value and reproduction | regeneration side hash value by the hash value collation means in the receiver of the signal synchronization system which concerns on embodiment of this invention. It is a flowchart for demonstrating the flow of a process in the transmitter of the signal synchronous system which concerns on embodiment of this invention. It is a flowchart for demonstrating the flow of a process in the receiver of the signal synchronization system which concerns on embodiment of this invention. It is a block diagram for demonstrating the structure of the signal synchronization system which concerns on the modification of embodiment of this invention.

Hereinafter, a signal synchronization system according to an embodiment of the present invention will be described with reference to the drawings as appropriate.
As shown in FIG. 1, a signal synchronization system 1 according to an embodiment of the present invention includes a transmission device 2 and a reception device 3.
Here, the transmission device 2 includes an encoding unit 21 and a synchronization information generation unit (synchronization information generation device) 22. The receiving device 3 includes a decoding unit 31 and a synchronous data reproducing unit (synchronous data reproducing device) 32.

  The encoding means 21 divides the input signal into predetermined signal sections and performs compression encoding for each predetermined signal section to generate a bit stream. Here, the type of input signal does not matter. For example, examples of the input signal include a video signal and an audio signal. Accordingly, the output signal output from the receiving device 3 is not limited to the same type as the input signal, and for example, a video signal or an audio signal is applicable.

  Here, as shown in FIG. 2, the encoding means 21 divides the input signal in units of frames and generates a bit stream in units of frames. FIG. 2 illustrates the frames 1 to 4 of the input signal. The “predetermined signal section of the input signal” is not limited to a frame, but may be a part (block) of a frame or a plurality of frames may be bundled. The minimum unit is one pixel unit of the frame.

  In the signal synchronization system 1 shown in FIG. 1, the encoding means 21 may be a reversible method or an irreversible method. For example, MPEG-1, MPEG-2, MPEG-4, MPEG-4 AVC | H. H.264, Motion JPEG or other existing moving image encoding schemes may be used, and still image encoding schemes such as JPEG may be used. The encoding unit 21 is paired with the decoding unit 31 of the receiving device 3.

  The decoding unit 31 decodes the bit stream generated by the encoding unit 21 and restores the input signal. When the encoding unit 21 is based on a reversible method, the output from the decoding unit 31 matches the output from the encoding unit 21. On the other hand, when the encoding unit 21 uses an irreversible method, the output from the decoding unit 31 does not always coincide with the output from the encoding unit 21. For example, the output from the decoding unit 31 may include deterioration with respect to the output from the encoding unit 21. In general, the lower the compression rate, the higher the degree of matching.

  The decoding unit 31 decodes the bit stream by a decoding method corresponding to the encoding method employed by the encoding unit 21 and restores a signal corresponding to a predetermined signal section of the input signal. The signal decoded in this way is output as an output signal as shown in FIG.

  In the signal synchronization system 1 shown in FIG. 1, the encoding means 21 and the decoding means 31 are connected via the transmission means 4. That is, the bit stream generated by the encoding unit 21 is transmitted to the decoding unit 31 by the transmission unit 4.

  Although not shown, the bit stream output from the encoding unit 21 is stored in the storage unit, and the bit stream stored in the storage unit is decoded by the decoding unit 31 to correspond to a predetermined signal section of the input signal. You may comprise so that a signal may be decompress | restored. In this case, the storage means may be on one or both of the transmission side and the reception side. The decoding unit 31 may directly read out the bitstream stored in the storage unit without passing through the transmission unit 4.

  For example, when a signal transmitted from the transmission device 2 to the reception device 3 is immediately decoded by the reception device 3 as in broadcasting, the storage unit may not be provided. In the case where a signal is transmitted to the reception device 3, storage means is provided on either or both of the transmission side and the reception side.

  Further, the synchronization information generation means 22 of the transmission device 2 or the synchronization data reproduction means 32 of the reception device 3 may directly access the storage means (not shown) without going through the transmission means 4. In addition, for example, when the recording device in which data is recorded in the transmission device 2 is reproduced by the reception device 3, the transmission unit 4 can be omitted. Further, when the receiving device 3 records and reproduces data in the own device, the transmission means 4 can be omitted.

The transmission means 4 may be wired or wireless. For example, broadcasting using radio waves or cable lines may be used, or a communication network such as the Internet may be used.
In the signal synchronization system 1, the synchronization information generation unit 22 of the transmission device 2 and the synchronization data reproduction unit 32 of the reception device 3 are further connected via the transmission unit 4.

  Although not shown, the output from the synchronization information generating means 22 of the transmitting device 2 is accumulated in the accumulating means, and the data accumulated in the accumulating means is provided to the synchronous data reproducing means 32 of the receiving device 3. It doesn't matter. In this case, the storage means (not shown) may be on either the transmission side or the reception side or both.

  In the signal synchronization system 1, the transmission means 4 is responsible for both the connection from the encoding means 21 to the decoding means 31 and the connection from the synchronization information generating means 22 to the synchronous data reproducing means 32 as described above. . The connection from the encoding means 21 to the decoding means 31 and the connection from the synchronization information generating means 22 to the synchronous data reproducing means 32 may be connected by separate transmission means, not limited to such a configuration. . For example, it is conceivable that the connection from the encoding means 21 to the decoding means 31 is constituted by a broadcast wave, while the connection from the synchronization information generating means 22 to the synchronous data reproducing means 32 is constituted by a communication network.

  Next, each configuration of the synchronization information generating unit 22 of the transmission device 2 will be described with reference to FIGS. As shown in FIG. 1, the synchronization information generation unit 22 includes a decoding unit 221, a hash value calculation unit (generation-side hash value calculation unit) 222, a multiplexing unit 223, and a data encoding unit 224.

  The decoding unit 221 sequentially decodes the bit stream generated by the encoding unit 21 and sequentially restores signals corresponding to predetermined signal sections (here, frames) of the input signal. The decoding unit 221 has the same input / output relationship as the decoding unit 31 of the receiving device 3 described above. The decoding unit 221 may be implemented in the same manner as the decoding unit 31 of the receiving device 3 or may be implemented differently. For example, the decoding unit 221 may be configured by hardware, and the decoding unit 31 of the receiving device 3 may be configured by software, or vice versa.

  The time required for decoding the bit stream in the decoding unit 221 may be the same as or different from the time required for decoding the bit stream in the decoding unit 31 of the receiving device 3. Further, when local decoding (local decoding) is performed inside the encoding means 21, the decoding means 221 can be omitted by replacing the locally decoded signal with the output from the decoding means 221. Good. The decoded signal thus obtained (hereinafter, this signal is referred to as “local decoded signal” for convenience) is output to the hash value calculation means 222.

  In the configuration of FIG. 1, the hash value calculation means 222 calculates a hash value h (f) (synchronization information) for each frame f with respect to the local decoded signal (here, a frame) sequentially decoded by the decoding means 221. To do. Hereinafter, the hash value h (f) for each frame f calculated by the hash value calculation means 222 is referred to as “generation-side hash value h (f)”.

  The hash function used by the hash value calculation means 222 for the hash value calculation is arbitrary. The frame f of the locally decoded signal is composed of N (N is a natural number) sample points, and the n-th (n = 0, 1,..., N−1) sample values in the frame f are X (f N), the hash value calculation means 222 calculates the sum of the sample values X (f; n) as shown in the following equation (1), for example, and generates the hash value h on the generation side (F) may be used.

Further, the hash value calculation means 222 uses, for example, a predetermined number sequence (a _n ) _{n = 0, 1,..., N−1} to calculate a weighted sum as shown in the following equation (2). It is good also as operation and making this the production | generation side hash value h (f).

  Further, the hash value calculation means 222 uses, for example, a predetermined natural number M (M is 2 or more), and calculates the remainder when the weighted sum is divided by the predetermined natural number M as shown in the following equation (3). The generation-side hash value h (f) may be used.

  In the above equation (3), the operator% is a remainder operator, and% M means obtaining a remainder when divided by a natural number M.

  Furthermore, the hash value calculation means 222 applies a recurrence formula as shown in the following formula (4) to, for example, an arbitrary predetermined function F and function G and an arbitrary predetermined scalar value a. Thus, the generation-side hash value h (f) may be calculated.

  Here, the function F, the function G, and the scalar value a in the above-described equation (4) can be defined as the following equation (5), for example.

  Note that the hash function need not be a complete hash function. Further, it is desirable that the generation-side hash value h (f) can be expressed by a data amount sufficiently smaller than the code amount assigned to the frame f. For example, the generation-side hash value h (f) can be expressed by a numerical value of about 8 bits to 256 bits. In the example shown in FIG. 2, the generation-side hash value h (f) is expressed by 32 bits. The generation-side hash value h (f) calculated in this way is output to the multiplexing unit 223.

For example, the hash value calculation unit 222 calculates the generation-side hash value h (f) by using any one of the hash functions shown in the above formulas (1) to (4). For example, when the luminance value of the sample points adjacent frame f as close to each other, according to the equation (2) or formula (3), by varying the scalar value a _n, larger changes the respective values This is preferable.

For example, assuming a frame composed of two pixels, a luminance value is simply calculated between a frame where the luminance values of the two pixels are aligned with “3,4” and a frame where the luminance values of “4,3” are aligned. In any case, the generation-side hash value h (f) becomes the same value. However, according to the expression (2) or (3) described above, by generating different scalar values a _n (here, a ₁ and a ₂ ), a frame in which the luminance values are aligned with “3, 4” is generated. The side hash value h (f) and the generation side hash value h (f) of the frames aligned with “4, 3” can be made different from each other. At this time, as the major digit scalar values a _n, a wider range of numbers that can be selected, in a frame lined luminance value is the "3,4" aligned with the frame and the "4,3", more difference It is preferable because it appears large. In principle, if the scalar values a ₁ and a ₂ are slightly different from each other, the generation side hash values h (f) and “4, 3” of the frames whose luminance values are aligned with “3,4” are obtained. The generation-side hash value h (f) for the arranged frames can be made different.
Furthermore, according to the above-described equation (3), by setting the natural number M to an appropriate value, the generation-side hash value h (f) is within an appropriate numerical range (for example, about 8 bits to 256 bits). be able to.

When the division unit of the input signal in the encoding unit 21 is one pixel, the hash value calculation unit 222 uses the luminance value itself of the one pixel as the generation hash value h (f).
For example, in the example illustrated in FIG. 2, the hash value calculation unit 222 calculates “1F02875E” as the generation-side hash value h (f) corresponding to the frame 1 of the local decoded signal. The hash value calculation means 222 calculates the generation-side hash value h (f) in the same manner for frames 2 and thereafter.

  The multiplexing means 223 multiplexes the data to be associated with the frame f of the input signal and the generation-side hash value h (f) obtained for the frame f of the input signal by the hash value calculation means 222 to obtain synchronization information. Multiplexed data is generated. Here, “data to be associated with the frame f of the input signal” is data synchronized with the frame f of the input signal, and may be, for example, time information (time code) or data broadcasting content. Or data such as metadata. Hereinafter, time information will be described as an example of “data to be associated with the frame f of the input signal”. In the following, time information (time code) at time f is set to t (f).

  As shown in FIG. 2, the multiplexing unit 223 receives the f-th frame of the input signal measured by the measuring unit (not shown) and inputs the f-th frame of the input signal to the encoding unit 21. The delay time Δf until (f) is obtained is input, and the generation-side hash value h (f) and time information t (f) are correctly associated and multiplexed in consideration of the delay time Δf. At the time f + Δf, the calculation of the generation-side hash value h (f) by the hash value calculation unit 222 is completed, but the multiplexing unit 223 uses the time code t (f + Δf of the time in the input time information (time (f + Δf)). The time code t (f) corresponding to the correct time is obtained by tracing back the input)) by the delay time Δf, and is multiplexed with the generation-side hash value h (f) to generate synchronization information. The synchronization information generated in this way is output to the data encoding means 224.

  For example, in the example illustrated in FIG. 2, the multiplexing unit 223 includes the time information “10: 02: 03.12” to be associated with the frame 1 in the generation-side hash value “1F02875E” generated for the frame 1. Is multiplexed to generate synchronization information. Multiplexing means 223 generates synchronization information in the same manner from frame 2 onward.

  As shown in FIG. 1, the data encoding unit 224 encodes the synchronization information generated by the multiplexing unit 223 to generate a bit stream of synchronization information. The data encoding unit 224 generates a bitstream by reversibly encoding the synchronization information using a reversible encoding method (such as GIF or reversible JPEG) from existing encoding methods. Note that the data encoding means 224 may perform compression by entropy encoding or error correction by providing redundancy. Further, information regarding the hash function used in the hash value calculation means 222 may be added to the bit stream of the synchronization information as side information.

  As shown in FIG. 1, the bit stream of the synchronization information is sequentially output to the transmission unit 4 in time series, and is transmitted to the data encoding unit 224 via the transmission unit 4. Transmitted to means 322. Note that the multiplexing unit 223 may transmit the synchronization information as it is through the transmission unit 4 to the data decoding unit 322 of the receiving device 3, and in this case, the data encoding unit 224 may be omitted. In FIG. 2, the data encoding means 224 is omitted.

  Next, each structure of the synchronous data reproduction | regeneration means 32 of the receiver 3 is demonstrated with reference to FIG. As shown in FIG. 1, the synchronous data reproduction means 32 includes a hash value calculation means (reproduction-side hash value calculation means) 321, a data decryption means 322, and a hash value collation means 323.

  The hash value calculation unit 321 calculates a hash value h (f) for the f-th frame of the signal decoded by the decoding unit 31. The hash value calculation means 321 uses the same hash function as the hash function used by the hash value calculation means 222 of the transmission device 2 to calculate the generation-side hash value h (f), and uses the same hash function as the reproduction-side hash value h (f). Calculate. The reproduction-side hash value h (f) obtained in this way is output to the hash value matching unit 323.

  For example, in the example illustrated in FIG. 3, the hash value calculation unit 321 calculates “1F02875E” as the reproduction-side hash value h (f) corresponding to the local decoded signal of frame 1 by calculation. The hash value calculation means 321 also obtains the reproduction-side hash value h (f) in the same manner for frames 2 and thereafter. Here, the reproduction-side hash values h (f) obtained for the frames 1 to 4 by the hash value calculation means 321 are calculated for the frames 1 to 4 by the hash value calculation means 222 as shown in FIG. It matches the obtained generator hash value h (f).

  The data decoding unit 322 sequentially inputs a bit stream of synchronization information generated by the data encoding unit 224 of the transmission device 2 and transmitted through the transmission unit 4 in time series, decodes this bit stream, The synchronization information in which the time information and the generation-side hash value h (f) are multiplexed is sequentially restored. The synchronization information sequentially decoded in this way is sequentially output to the hash value matching unit 323 along a time series. When the data encoding unit 224 is omitted on the transmission side, the data decoding unit 322 is omitted. In FIG. 3, the data decoding means 322 is omitted.

  The hash value collating unit 323 includes the reproduction side hash value h (f) calculated by the hash value calculating unit 321 and the generation side hash value h (f) included in the data sequence of the synchronization information sequentially output from the data decoding unit 322. ) Are sequentially searched, and a generator-side hash value h (f) having the same value as the reproduction-side hash value h (f) is searched from the synchronization information data string, and the generator-side hash value h (f) ) Is specified.

  The hash value matching unit 323 separates time information associated with the generation-side hash value h (f) that takes the same value as the reproduction-side hash value h (f), and outputs this time information (output time) as output data. . When data other than time information is multiplexed on the generation-side hash value h (f) on the transmission side, the hash value matching unit 323 outputs data other than the time information as output data.

  In the example illustrated in FIG. 3, the hash value matching unit 323, for example, includes time information “10: 02: 03.12” associated with the generation-side hash value “1F02875E” that is the same value as the reproduction-side hash value “1F02875E”. Are synchronized with the frame 1 corresponding to the reproduction-side hash value “1F02875E” and output. Hereinafter, association is performed in the same manner.

If the hash function used in the hash value calculation means 321 (and the hash value calculation means 222) is not a complete hash function, or if the local decoded signal takes the same value in different frames, the hash value matching means 323 In some cases, the association between the reproduction-side hash value h (f) and the generation-side hash value h (f) cannot be narrowed down to a single value. In such a case, for example, the hash value matching unit 323 is positioned before and after the reproduction-side hash value h (f) that is the target of the current association in the time series of the reproduction-side hash value h (f). The result of associating the reproduction-side hash values h (f−1) and h (f + 1) with the generation-side hash values h (f−1) and h (f + 1) is referred to. In the time series of the reproduction-side hash value h (f), the hash value matching unit 323 determines that the reproduction-side hash value is determined when the current association result is temporally separated from the previous and subsequent association results. Instead of associating h (f) with the generation-side hash value h (f), in the time series of the reproduction-side hash value h (f), the reproduction-side hash value h (f− The reproduction-side hash value h (f) located immediately after 1) may be regarded as the current association result.
That is, the reproduction-side hash values h (f−1) and h (f + 1) and the generation-side hash value h (f−1) that are located before and after the reproduction-side hash value h (f) that is the object of the current association. It is assumed that the association with h (f + 1) is correct, and the reproduction-side hash value h (f) that is the object of this association is generated between the generation-side hash values h (f−1) and h (f + 1). It is considered to be associated with the side hash value h (f).

  Further, for example, the hash value matching means 323 bundles the reproduction-side hash value h (f) of a certain frame and the reproduction-side hash values h (f−1) and h (f + 1) of ± 1 frame of this frame, Association may be performed by searching for a bundle of generator hash values having the same array as the bundle from the data string of the synchronization information. Thus, the error rate can be reduced to the third power by making the reproduction-side hash value a 3-frame bundle and collating it with the generation-side hash value for each bundle. Here, the reproduction-side hash value h (f) of a certain frame and the reproduction-side hash value h (f) of ± 1 frame of this frame are bundled, but not limited to this, it may be ± 2 frames or the like. +1 frame, -1 frame, etc.

  Here, as shown in FIG. 4, the reproduction-side hash value h (f) is “03, 41, 51, 52, 41, 23. It is assumed that the generation-side hash values h (f) are aligned with “... 51, 52, 41...” In order from the front along the time direction t. In this case, the hash value collating unit 323 associates the reproduction-side hash values “51” and “52” in time series, and then associates the reproduction-side hash value “41”. Here, in the example shown in FIG. 4, in the time series of the reproduction-side hash value h (f), there are two hash values “41” (between the hash value “23” and the hash value “52”, and the hash Between the value “51” and the hash value “03”).

  In this case, correctly, the reproduction-side hash value “41” between the reproduction-side hash value “23” and the reproduction-side hash value “52” should be associated with the generation-side hash value “41”. However, if the hash value matching unit 323 mistakenly sets the reproduction-side hash value “41” between the reproduction-side hash value “51” and the reproduction-side hash value “03” as the generation-side hash value “41”. In the case of association, the association result of the reproduction-side hash value “41” is returned in time to the association result of the reproduction-side hash values “51” and “52”. In such a case, the hash value matching unit 323 considers that an error has occurred in the association, and performs association again. According to this, even when there are two or more candidates for the reproduction-side hash value h (f) that can be associated with the generation-side hash value h (f), the reproduction-side hash value h (f) and the generation-side hash value h (f) are generated. It is possible to correctly associate the side hash value h (f). In the example shown in FIG. 4, the hash value is simplified for ease of explanation.

  Further, for example, when the signal decoded on the reception side includes noise or the like that was not included in the signal on the transmission side, the reproduction-side hash value h (f) becomes the corresponding generation-side hash value h ( The value may change to a value different from f). For example, in the example shown in FIG. 4, in the time series of the reproduction-side hash value h (f), the reproduction-side hash value h (f) should be “52”. Has changed to “58”. Even in such a case, the hash value matching unit 323 refers to the association result of the preceding and following reproduction-side hash values h (f) (the reproduction-side hash values h (f) of ± 1 frame in FIG. 4). By doing so, it is possible to guess that the reproduction-side hash value “58” was originally the reproduction-side hash value “52”, so that correct association is possible.

  If the generator hash value h (f) having the same value as the reproduction hash value h (f) of a frame is not found in the data string of the synchronization information, the hash value matching unit 323 temporarily The association of the reproduction side hash value h (f) of the frame is suspended, the association of the reproduction side hash value h (f) of the frame after the suspended frame is performed first, and the association result is used. Alternatively, the reproduction-side hash value h (f) of the reserved frame may be associated. For example, when the hash value matching unit 323 can associate the reproduction-side hash value h (f) for the last two frames of the reserved frame, the hash value collating unit 323 can associate the reproduction-side hash value h (f) of the reserved frame. By searching the synchronization information data string for the same pattern as the playback-side hash value h (f) for the frame, the generation-side hash value corresponding to the playback-side hash value h (f) of the reserved frame is specified. May be. Although not shown, in such a case, the synchronous data reproduction means 32 is provided with a buffer that temporarily stores the reproduction-side hash value h (f) calculated by the hash value calculation means 321.

  Although not shown, the receiving device 3 includes a buffer for accumulating the local decoded signal restored by the decoding unit 31, the synchronous data reproducing unit 32 further includes a synchronous reproducing unit, and the synchronous reproducing unit includes the synchronous data reproducing unit. The data to be associated with the local decoded signal may be input from 32 hash value matching means 323, and the local decoded signal may be read from the buffer at the input timing and output together with the data. The receiving device 3 further includes a buffer (not shown) in which the synchronous data reproducing means 32 stores the data specified by the hash value collating means 323, and the synchronous reproducing means and the local decoded signal and the local portion at an appropriate timing. Data to be associated with the decoded signal may be read from each buffer and output.

Next, the flow of processing performed in the signal synchronization system 1 according to the embodiment of the present invention will be described with reference to FIGS. Here, FIG. 5 shows the flow of processing on the transmission side in the signal synchronization system 1, and FIG. 6 shows the flow of processing on the reception side in the signal synchronization system 1.
As shown in FIG. 5, the signal synchronization system 1 inputs a signal (video signal or audio signal) by the encoding means 21 of the transmission device 2 (step S1). In the signal synchronization system 1, the encoding unit 21 of the transmission device 2 compresses and encodes a predetermined signal section of the input signal to generate a bit stream (step S2).

  In the signal synchronization system 1, the bit stream is output to the decoding unit 221 and the transmission unit 4 of the synchronization information generation unit 22 by the encoding unit 21 of the transmission apparatus 2 (step S3). Here, although not shown, the signal synchronization system 1 receives the bit stream generated by the encoding unit 21 of the transmission device 2 by the transmission unit 4 and transmits this bit stream to the decoding unit 31 of the reception device 3. To do.

  Next, the signal synchronization system 1 inputs the bit stream generated by the encoding unit 21 by the decoding unit 221 in the synchronization information generation unit 22 of the transmission device 2, decodes this bit stream, and determines the predetermined input signal. A locally decoded signal in which the signal interval is restored is obtained (step S4). In the signal synchronization system 1, the local decoding signal is output to the hash value calculation unit 222 by the decoding unit 221 in the synchronization information generation unit 22 of the transmission device 2.

  Further, in the signal synchronization system 1, the local decoding signal is input from the decoding unit 221 by the hash value calculation unit 222 in the synchronization information generation unit 22 of the transmission device 2, and the generation-side hash value h (f) is obtained from the local decoding signal. Is calculated (step S5). The signal synchronization system 1 outputs the obtained generation hash value h (f) to the multiplexing unit 223 by the hash value calculation unit 222 in the synchronization information generation unit 22 of the transmission device 2.

  Subsequently, the signal synchronization system 1 inputs the generation-side hash value h (f) obtained by the hash value calculation unit 222 by the multiplexing unit 223 in the synchronization information generation unit 22 of the transmission device 2. Further, the signal synchronization system 1 inputs data (here, time information) synchronized with a predetermined signal section of the input signal from the outside by the multiplexing unit 223 in the synchronization information generation unit 22 of the transmission device 2 (step S6). ).

  Then, the signal synchronization system 1 multiplexes the generation-side hash value h (f) and the time information by the multiplexing unit 223 in the synchronization information generation unit 22 of the transmission device 2 to generate multiplexed data that is synchronization information. (Step S7). The signal synchronization system 1 outputs the synchronization information generated by the multiplexing unit 223 in the synchronization information generation unit 22 of the transmission device 2 to the data encoding unit 224 as synchronization information.

  Then, the signal synchronization system 1 compresses and encodes the synchronization information generated by the multiplexing unit 223 by the data encoding unit 224 in the synchronization information generation unit 22 of the transmission device 2 to generate a bit stream of the synchronization information ( Step S8). The signal synchronization system 1 outputs the bit stream of the generated synchronization information to the transmission unit 4 by the data encoding unit 224 in the synchronization information generation unit 22 of the transmission device 2 (step S9).

  Although not shown, the signal synchronization system 1 inputs a bit stream of the synchronization information generated by the data encoding unit 224 in the synchronization information generation unit 22 of the transmission device 2 by the transmission unit 4, and the bit of the synchronization information The stream is transmitted to the data decoding unit 322 in the synchronous data reproduction unit 32 of the receiving device 3.

Next, with reference to FIG. 6, the flow of processing in the receiving device 3 of the signal synchronization system 1 will be described.
Here, the receiving device 3 of the signal synchronization system 1 includes a buffer (not shown) that stores the local decoded signal restored by the decoding unit 31, and the synchronous data reproduction unit 32 includes the local decoded signal stored in the buffer, It is assumed that there is provided synchronous reproduction means for reproducing the data to be associated with the local decoded signal in synchronization.

  As illustrated in FIG. 6, the signal synchronization system 1 receives the bit stream generated by the encoding unit 21 of the transmission device 2 via the transmission unit 4 by the decoding unit 31 of the reception device 3 (step S11). The signal synchronization system 1 decodes this bit stream by the decoding unit 31 of the receiving device 3 to obtain a local decoded signal obtained by restoring a predetermined signal section of the input signal (step S12). In the signal synchronization system 1, the decoding unit 31 of the receiving device 3 outputs the local decoded signal to the hash value calculation unit 321 of the synchronization data reproduction unit 32 and a buffer (not shown), respectively.

  Next, in the signal synchronization system 1, the local decoding signal is input from the decoding unit 31 by the hash value calculation unit 321 in the synchronous data reproduction unit 32 of the receiving device 3, and the reproduction-side hash value h (f ) Is calculated (step S13). The signal synchronization system 1 outputs the obtained reproduction-side hash value h (f) to the hash value collating unit 323 by the hash value calculating unit 321 in the synchronous data reproducing unit 32 of the receiving device 3.

  Further, the signal synchronization system 1 uses the data decoding unit 322 in the synchronization data reproduction unit 32 of the reception device 3 to generate the bit stream of the synchronization information generated by the data encoding unit 224 in the synchronization information generation unit 22 of the transmission device 2. Reception is performed via the transmission means 4 (step S14).

  Subsequently, the signal synchronization system 1 decodes the bit stream of the synchronization information by the data decoding unit 322 in the synchronization data reproducing unit 32 of the receiving device 3, and the time information and the generation-side hash value h (f) are multiplexed. The synchronization information that is the multiplexed data is restored (step S15). The signal synchronization system 1 outputs the restored synchronization information to the hash value collating unit 323 by the data decoding unit 322 in the synchronous data reproducing unit 32 of the receiving device 3.

The signal synchronization system 1 receives the reproduction-side hash value h (f) from the hash value calculation unit 321 and the synchronization from the data decoding unit 322 by the hash value matching unit 323 in the synchronous data reproduction unit 32 of the receiving device 3. Enter information. Then, the signal synchronization system 1 collates the reproduction-side hash value h (f) and the generation-side hash value h (f) by the hash value collation unit 323 in the synchronization data reproduction unit 32 of the reception device 3, and The time information associated with the generation hash value h (f) having the same value as the reproduction side hash value h (f) is searched and specified from the time series of the generation side hash value h (f) included in the data string. (Step S16). The signal synchronization system 1 outputs the identified time information to the synchronous reproduction means (not shown) by the hash value matching means 323 in the synchronous data reproduction means 32 of the receiving device 3.
Then, the signal synchronization system 1 reads a local decoded signal from a buffer (not shown) by a synchronous reproduction means (not shown) of the synchronous data reproduction means 32 of the receiving device 3, and outputs this local decoded signal together with time information (step S17). .
The signal synchronization system 1 operates as described above.

According to the signal synchronization system 1 according to the embodiment of the present invention described above, the transmission side (synchronization information generation side) generates the data synchronized with the predetermined signal section of the input signal and the predetermined signal section of the input signal. The synchronization information is configured with the generation-side hash value h (f). As a result, it is possible to synchronize with the predetermined signal section of the input signal on the receiving side (synchronous data reproduction side) without adding information for synchronization with the corresponding data to the input signal that is one of the transmission target signals. Therefore, the signal synchronization system 1 can link the predetermined signal section of the input signal and the data synchronized with the predetermined signal section of the input signal in the receiving device 3. The predetermined signal section and the data synchronized with the predetermined signal section of the input signal can be reproduced in synchronization.

  In the embodiment described above, the input signal (output signal) is a video signal or an audio signal and the input data (output data) is data other than time information or time information, as in a general data transmission format. Not limited to this. For example, if there is a free area in the audio stream that can embed the generator hash value, the input signal (output signal) can be a video signal and the input data (output data) can be an audio signal. . This makes it possible to synchronize the video signal and the audio signal on the receiving side.

<Modification>
The signal synchronization system 1 according to the embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. . Hereinafter, a signal synchronization system 1A according to a modification of the signal synchronization system 1 according to the first embodiment of the present invention will be described with reference to FIG. In the signal synchronization system 1A shown in FIG. 7, the same components as those in the signal synchronization system 1 described with reference to FIG.

  As illustrated in FIG. 7, the signal synchronization system 1 </ b> A includes a transmission device 2 </ b> A and a reception device 3. The transmission device 2A includes an encoding unit 21 and a synchronization information generation unit (synchronization information generation device) 22A. The synchronization information generation unit 22A includes a hash value calculation unit (generation-side hash value calculation unit) 222, a multiplexing unit 223, and a data encoding unit 224. That is, the signal synchronization system 1A illustrated in FIG. 7 is different from the signal synchronization system 1 illustrated in FIG. 1 in that the synchronization information generation unit 22A of the transmission device 2A does not include a decoding unit.

  That is, in the signal synchronization system 1A, the hash value calculation unit 222 of the synchronization information generation unit 22A of the transmission device 2A directly calculates a hash value from the input signal. In this signal synchronization system 1A, the encoding method used by the encoding means 21 of the transmission device 2A is limited to a reversible encoding method. In this case, the local decoded signal obtained by decoding the bit stream generated by the encoding unit 21 in the transmitting apparatus 2 </ b> A by the decoding unit 31 of the receiving apparatus 3 matches the input signal to the encoding unit 21.

  Therefore, in the hash value calculation means 222 of the synchronization information generation means 22A of the transmission apparatus 2A, the generation hash value h (f) obtained directly from the input signal and the hash value calculation means 321 of the synchronization data reproduction means 32 of the reception apparatus 3 Therefore, the reproduction-side hash value h (f) obtained from the local decoded signal matches. Therefore, the signal synchronization system 1A can also synchronize the output signal and the output data to be associated with the output signal on the receiving side.

  The synchronization information generating means 22 and 22A and the synchronization data reproducing means 32 of the signal synchronization system 1 or 1A described above may be configured as devices. Further, the synchronization information generation means 22, 22A and the synchronization data reproduction means 32 may be programs (synchronization information generation program or synchronization data reproduction program) described so that the processing in each means can be executed in the computer. It is.

1, 1A signal synchronization system 2, 2A transmitter 21 encoding means 22, 22A synchronization information generation means (synchronization information generation apparatus)
221 Decryption means 222 Hash value calculation means (generation-side hash value calculation means)
223 Multiplexing means 224 Data encoding means 3 Receiving device 31 Decoding means 32 Synchronous data reproducing means (Synchronous data reproducing device)
321 Hash value calculation means (playback hash value calculation means)
322 Data decryption means 323 Hash value collation means 4 Transmission means

Claims (6)

A synchronization information generating device for generating synchronization information for reproducing data synchronized with a predetermined signal interval of an input signal on the reproduction side in synchronization with a signal corresponding to the predetermined signal interval of the input signal,
Decoding means for inputting encoded data of the input signal and sequentially decoding a signal corresponding to a predetermined signal section of the input signal from the encoded data;
Generation side hash value calculation means for calculating a generation side hash value with a predetermined hash function for the signal decoded by the decoding means;
Multiplexing means for generating multiplexed data of the generating hash value calculated by the generating hash value calculating means and data synchronized with a predetermined signal section of the input signal as the synchronization information and sequentially outputting the data, A synchronization information generating apparatus comprising: A synchronization information generating device for generating synchronization information for reproducing data synchronized with a predetermined signal interval of an input signal on the reproduction side in synchronization with a signal corresponding to the predetermined signal interval of the input signal,
Generating hash value calculation means for calculating a generating hash value by a predetermined hash function for a predetermined signal section of the input signal;
Multiplexing means for generating multiplexed data of the generating hash value calculated by the generating hash value calculating means and data synchronized with a predetermined signal section of the input signal as the synchronization information and sequentially outputting the data, A synchronization information generating apparatus comprising: The synchronization information that is multiplexed data of the generation-side hash value generated corresponding to the predetermined signal section of the input signal and the data synchronized with the predetermined signal section of the input signal is sequentially input, and based on this synchronization information A synchronous data reproducing device for reproducing data synchronized with a predetermined signal section of the input signal,
A signal corresponding to a predetermined signal section of the input signal, which is decoded from the encoded data of the input signal, is sequentially input, and a hash function used for calculating the generator hash value is obtained for the decoded signal; A reproduction-side hash value calculation means for calculating a reproduction-side hash value by the same hash function;
The reproduction-side hash value calculated by the reproduction-side hash value calculating means and the generation-side hash value included in the data string of the synchronization information are sequentially compared to obtain the same value as the reproduction-side hash value And a hash value matching means for searching for the data associated with the generation-side hash value. The hash value matching means includes
The reproduction-side hash value and the bundle of the generation-side hash values having the same array as the bundle of reproduction-side hash values before and after the reproduction-side hash value are searched from the data string of the synchronization information, and the bundle of reproduction-side hash values 4. The synchronous data reproduction device according to claim 3, wherein the data associated with each of the plurality of generation hash values included in the generation hash value bundle having the same array is searched.   A synchronization information generation program for causing a computer to function as the synchronization information generation apparatus according to claim 1.   A synchronous data reproduction program for causing a computer to function as the synchronous data reproduction device according to claim 3 or 4.

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