JP4549310B2 - Digital broadcast storage and playback device - Google Patents

Description

  The present invention relates to an apparatus for accumulating and playing back a scrambled digital broadcast TS, and in particular, when an TS (transport stream) is accumulated in a storage medium without being descrambled, an ECM (Entitlement Control Message) and an I picture The present invention relates to an apparatus for performing special reproduction by estimating the position of the image.

  In the server-type broadcast stream content distribution method, which is one of the digital broadcast methods, TS is stored while being scrambled and descrambled during reproduction. Examples of conventional special reproduction methods for server-type broadcasting are shown in Patent Document 1 and Patent Document 2.

JP 2004-260522 A JP 2002-247547 A

  In the method of Patent Document 1, an ECM (program information storing a scramble key or the like) is inserted immediately before an I picture on the transmission side, and the position of the I picture is specified by detecting the ECM on the reception side. In the method of Patent Document 2, a list for associating an ECM or I picture with data in a storage medium at the time of accumulation is created, and the I picture is detected by referring to the list at the time of reproduction. The method of inserting an ECM before an I picture on the transmission side has a problem that it cannot cope with a broadcast in which no ECM is inserted before an I picture. Further, the method of creating a list at the time of accumulation has a problem that the processing at the time of accumulation increases, and at the same time, it is difficult to accumulate multiple channels.

  As a method of performing special reproduction when processing is not performed during transmission or storage, a method of speeding up processing such as reading from a storage medium or descrambling can be considered. However, when reading from the storage medium at a high speed, the processing of the storage medium control unit increases.

  An object of this invention is to provide the apparatus which can perform special reproduction | regeneration with few processes.

The present invention
A device for storing and playing back digital broadcasts,
A storage medium for storing scrambled TS data;
ECM interval estimation means for calculating a read range width determining ECM interval value based on the ECM interval in the TS data read from the storage medium when reproducing the TS data stored in the storage medium;
When reproducing the TS data stored in the storage medium, based on the I picture interval in the TS data read from the storage medium, a read range width determining I picture interval value and a jump destination determining I picture interval I picture interval estimation means for calculating a value;
Based on the read range width determination ECM interval value calculated by the ECM interval estimation means, the read range width determination I picture interval value and the jump destination determination I picture interval value calculated by the I picture interval estimation means, Storage medium control means for determining a range in which TS data is intermittently read out during special reproduction,
There is provided a digital broadcast storage / reproduction apparatus comprising: reproduction processing means for receiving TS data read from a storage medium by a storage medium control means and decoding and outputting only an I picture.

  According to the present invention, when special reproduction of scrambled TS data is performed, TS data can be read intermittently by estimating the positions of ECM and I picture, and special reproduction is performed with less processing. There is an effect that can be.

  The digital broadcast storage / playback apparatus according to the present invention will be described below.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a digital broadcast storage / playback apparatus according to the first embodiment. In FIG. 1, 1 is an antenna that receives a digital broadcast, 2 is a demodulator that demodulates the received signal and outputs a TS, 3 is a time stamp adding unit that adds a time stamp to the demodulated TS, and 5 is a TS storage The storage medium 4 stores the TS in the storage medium 5 during storage and reads the TS from the storage medium 5 during playback, the ECM detection unit 6 detects ECM from the TS data, and 7 calculates the ECM interval. To ECM interval estimation unit for estimation, 8 is a descrambling unit for unscrambling the read TS data, 9 is a demux unit for separating the descrambled TS data into image and audio data, and 16 is an I picture for extracting an I picture An extraction unit 12 decodes an image, audio data input from the demax unit, or an I picture extracted from the I picture extraction unit. A decoding unit for converting the image into an image, 13 a display unit for displaying the decoded image, 17 an I picture interval estimation unit for calculating or estimating an interval between I pictures, 18 a clock generator, and 20 a reproduction for performing reproduction processing. It is a processing unit.
In the present embodiment, the ECM interval value and the I picture interval value represented by the difference between the time stamp values are used.

First, at the time of accumulation, the antenna 1 receives a digital broadcast.
The received signal is demodulated by the demodulator 2 and output as TS. The time stamp adding unit 3 uses the clock from the clock generator 18 to add a time stamp to the demodulated TS.
The storage medium control unit 4 stores the TS added with the time stamp in the storage medium 5.
At this time, a list associating the time stamp with the position on the storage medium 5 is stored in the storage medium 5 so that it can be read at high speed if the time stamp is known during reproduction.
As for the ECM, the received ECM may be stored as it is, or another ECM may be newly created and stored.

  The I picture detection unit 10 detects the MPEG sequence header from the image data output from the demux unit 9 and detects the I picture. The sequence header is an abbreviation of GOP (Group Of Picture; in the case of MPEG2 in digital broadcasting, 1 GOP usually consists of 15 images, and the time for displaying 1 GOP image data is about 0.5 seconds). .

  During normal reproduction, the storage medium control unit 4 reads TS from the storage medium 5 in order according to the value of the added time stamp using the same clock from the clock generator 18 as at the time of storage. The read TS is input to the reproduction processing unit 20.

In the reproduction processing unit 20, the ECM detection unit 6 detects an ECM from the read TS, and decrypts the detected ECM cipher. When the ECM detection unit 6 detects an ECM, a time stamp value at that time is output and supplied to the ECM interval estimation unit 7. The TS read from the storage medium 5 is descrambled by the descrambling unit 8 by the ECM decoded by the ECM detection unit 6.
The descrambled TS is separated into image data and audio data by the demax unit 9. The image data and audio data are decoded by the decoding unit 12 and output as images and audio. The image and sound output from the reproduction processing unit 20 are displayed on the display unit 13.

  The ECM interval estimation unit 7 receives the ECM time stamp value in the reproduction data detected by the ECM detection unit 6, and calculates or estimates the read range width determining ECM interval value EIR represented by the difference between the time stamp values. To do. As described later, the ECM interval value EIR for reading range width determination is used for determining the reading range width at the jump destination (estimating the optimum reading range width) at the time of special reproduction.

FIG. 2 is a block diagram showing the configuration of the ECM interval estimation unit 7 used in the first embodiment. The illustrated ECM interval estimation unit 7 includes an ECM time stamp calculation unit 23 and an ECM estimation calculation unit 25.
The ECM time stamp calculation unit 23 calculates a difference between two ECM time stamp values detected in succession by the ECM detection unit 6 in the reproduction data, and obtains the reproduction data ECM interval value REI. Used as detection means.
The ECM estimation calculation unit 25 obtains a read range width determination ECM interval value EIR based on one or a plurality of reproduction data ECM interval values REI calculated by the ECM time stamp value calculation unit 23. Used as computing means.

  The read range width determining ECM interval value EIR is obtained, for example, by averaging the reproduction data ECM interval value REI detected by the ECM detection unit 6. The average value referred to here is, for example, an average value (moving average value) of a recent predetermined number (K) of ECM interval values. By using the moving average, the ECM interval can be estimated with higher accuracy. When obtaining K moving averages, reducing the number of K makes it easier to follow the fluctuation of the interval and is effective when the fluctuation is large. On the other hand, when the number of K is increased, it becomes difficult to be affected by temporary fluctuations in the ECM interval value.

Alternatively, it may be a weighted average value of a predetermined number (K) of ECM interval values in the past (the sum of weighting coefficients is 1). In this case, for example, a larger weight may be given to the newer reproduction data ECM interval value REI. In addition, a moving average value of (K−1) ECM interval values excluding the latest one of a predetermined number (K) of ECM interval values in the past and a weighted average value of the latest ECM interval values are obtained. You may ask for it. When obtaining such a weighted average, increasing the weighting coefficient of the recent ECM interval value makes it easier to follow the fluctuation.
Furthermore, the latest one of the reproduction data ECM interval values REI itself (that is, without obtaining an average of the reproduction data ECM interval values REI) may be used as the read range width determining ECM interval value EIR.

  Furthermore, the maximum value of the most recent predetermined number of reproduction data ECM interval values REI detected by the ECM time stamp calculation unit 23 may be used as the ECM interval value EIR for reading range width determination. If the maximum value is used as the ECM interval value EIR for determining the reading range width, as will be described in detail later, even when the ECM interval varies, two consecutive ECMs are surely included in the reading range at the time of special reproduction. Can be. (However, the amount of data to be read increases.)

  The I picture interval estimation unit 17 receives the time stamp value of the I picture (the start position) in the reproduction data detected by the I picture detection unit 10, and determines the jump destination determination I picture interval value GIJ and the reading range width. The I picture interval value GIR is calculated. The jump destination determining I picture interval value GIJ is used for determining the jump destination (reading start position) at the time of special playback (estimating the optimal jump destination), and the reading range width determining I picture interval value. The GIR is used for determining the read range width at the jump destination (estimating the optimum read range width) during special playback.

FIG. 3 is a block diagram showing a configuration of the I picture interval estimation unit 17 in the first embodiment.
The I picture interval estimation unit 17 includes an I picture time stamp calculation unit 11 and an I picture estimation calculation unit 21.
The I picture time stamp calculation unit 11 calculates the difference between the time stamp values of the sequence headers at the heads of two I pictures detected by the I picture detection unit 10 in succession in the reproduction data, and the reproduction data I picture This is used as reproduction data I picture interval value detection means for obtaining the interval value RGI.
The I picture interval represents the size of 1 GOP.
The I picture estimation calculation unit 21 is used to determine a jump destination determining I picture interval value GIJ and a reading range width based on one or a plurality of reproduction data I picture interval values RGI calculated by the I picture time stamp value calculating unit 10. This is used as a read area determining I picture interval value calculation means for calculating an I picture interval value GIR.

  The jump destination determination I picture interval value GIJ is obtained, for example, by averaging the reproduction data I picture interval value RGI detected by the I picture time stamp calculation unit 11. The average value referred to here is an average value (moving average value) of the recent predetermined number (K) of I picture interval values. By using the moving average, the I picture interval can be estimated with higher accuracy. When obtaining K moving averages, reducing the number of K makes it easier to follow the fluctuation of the interval and is effective when the fluctuation is large. On the other hand, when the number of K is increased, it becomes difficult to be affected by temporary fluctuation of the I picture interval value.

Alternatively, it may be a weighted average value (a sum of weighting coefficients is 1) of a predetermined number (K pieces) of I picture interval values in the past. In this case, for example, a larger weight may be given to the newer reproduction data I picture interval value RGI. In addition, a moving average value of (K−1) I picture interval values excluding the latest one of a predetermined number (K) of I picture interval values in the past, and a weight of a recent I picture interval value An average value may be obtained. When such a weighted average is obtained, if the weighting coefficient of the recent I picture interval value is increased, it becomes easier to follow the fluctuation.
Furthermore, the latest one of the reproduction data I picture interval values RGI itself (that is, without obtaining the average of the reproduction data I picture interval values RGI) may be used as the jump destination determining I picture interval value GIJ.

The calculation of the read range width determining I picture interval value GIR may be performed by the same method as the above-described calculation of the jump destination determining I picture interval value GIJ. In this case, the value obtained by the same calculation is determined as the jump destination determination. The I picture interval value GIJ for reading and the I picture interval value GIR for determining the reading range width can be used.
Instead, the maximum value of the most recent predetermined number of reproduction data I picture interval values RGI detected by the I picture detection unit 10 may be used as the I picture interval value GIR for reading range width determination. If the maximum value is used as the read range width determining I picture interval value GIR, as will be described in detail later, even when the I picture interval varies, two consecutive I pictures are included in the read range during special playback. It can be surely entered. (However, the amount of data to be read increases.)

The operation during normal playback has been described above. Next, the operation during special playback will be described.
Special reproduction here is high-speed reproduction (double-speed reproduction), and jump, read, jump, and read are repeated for the recording area of the storage medium in which data is stored.
To determine the jump destination, the jump destination determination I picture interval value GIJ obtained during normal playback immediately before switching to special playback or the jump destination determination I picture interval value GIJ obtained during special playback is used. . That is, when switching from normal playback to special playback, the jump destination determining I picture interval value GIJ obtained at the time of normal playback immediately before switching to special playback is used, and then playback data I obtained during special playback is used. The jump destination determination I picture interval value GIJ is recalculated using the picture interval value RGI, and is sequentially updated. When special playback is started without normal playback, two I pictures are detected, one playback data I picture interval value RGI is calculated, and then special playback processing similar to the above is performed. .
For the determination of the reading range width, the reading range width determining ECM interval value EIR or the reading range width determining I picture interval value GIR obtained during normal playback immediately before switching to the special playback is used. That is, when switching from normal playback to special playback, the read range width determining ECM interval value EIR or the read range width determining I picture interval value GIR obtained at the time of normal playback immediately before switching to special playback is used. Thereafter, using the reproduction data ECM interval value REI and the reproduction data I picture interval value RGI obtained during the special reproduction, the reading range width determining ECM interval value EIR and the reading range width determining I picture interval value GIR are recalculated. Update sequentially. When special playback is started without passing through normal playback, after two ECMs or two I pictures are detected and one playback data ECM interval value REI or playback data I picture interval value RGI is calculated, A special reproduction process similar to the above is performed.

  The determination of the jump destination depends on the playback speed. For example, in the case of N-times speed, the position after (N−0.5) times the jump destination determining I-picture interval value GIJ is read next time with reference to the leading position of the I picture in each reading range. The starting position, that is, the jump destination.

  In each reading, data in a range having a larger width from twice the second ECM interval value or two times the reading range width determining I picture interval value GIR from each reading start position. Is read. By doing this, even when the ECM interval and the I picture interval are larger than expected (estimation based on the average value, etc.), it is possible to reliably read two or more consecutive ECMs and two or more consecutive I pictures. Can do.

Hereinafter, the operation during special reproduction will be described in more detail.
The processing operation in the reproduction processing unit 20 when read from the storage medium 5 by the storage medium control unit 4 during special reproduction is the same as that during normal reproduction.

That is, when the ECM detection unit 6 detects ECM from the read TS data, the descrambling unit 8 descrambles the read TS data by using the key extracted by decrypting the ECM. The descrambled TS data is separated into image and audio data by the demax unit 9, and the I picture extraction unit 16 detects the MPEG sequence header from the image data output from the demax unit 9, and extracts the I picture. The extracted I picture is decoded by the decoding unit 12 and displayed on the display unit 13 for a certain period.
The I picture detecting unit 10 detects an MPEG sequence header from the image data output from the demux unit 9 and detects an I picture.

The ECM interval estimation unit 7 receives the ECM time stamp value in the reproduction data detected by the ECM detection unit 6 and calculates the ECM interval value EIR for reading range width determination.
The I picture interval estimation unit 17 receives the time stamp value of the I picture in the reproduction data detected by the I picture detection unit 10, and receives the jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value. GIR is calculated or estimated.

  The storage medium control unit 4 compares the read range width determination ECM interval value EIR with the read range width determination I picture interval value GIR, and if the read range width determination ECM interval value EIR is larger. As shown in FIG. 4A, the storage medium stores data included in a range (DEI) twice or larger than the ECM interval value EIR for reading range width determination so as to include at least two ECMs. Read by the control unit 4. On the other hand, when the reading range width determining I picture interval value GIR is larger, as shown in FIG. 4B, the reading range width determining I picture interval value GIR includes at least the head of two I pictures. The storage medium control unit 4 reads out TS data included in a range twice (DGI) or a range larger than that.

  At this time, special reproduction is performed by skipping I pictures outside the reading area (not to be read) in the storage medium 5 and reading only the I pictures in the reading area.

FIG. 5 is a flowchart showing a procedure for reading TS data from the storage medium 5 during special reproduction. Here, it is assumed that special playback is 6 × playback (N = 6 for N × playback).
First, when special playback is started in step ST1, in step ST2, a read range width determining ECM interval value EIR (represented by a difference between time stamp values) and a read range width determining I picture interval value GIR (time stamp value). (Represented by the difference).
If the read range width determining I picture interval value GIR is larger, the process proceeds to step ST3, and as shown in FIG. 4B, the read range width determining I picture interval value GIR is included in a range that is twice or more the read range width determining I picture interval value GIR. Read TS data. On the other hand, if the read range width determining ECM interval value EIR is larger, the process proceeds to step ST4, and as shown in FIG. 4A, the read range width determining ECM interval value EIR is included in a range that is twice or more the read range width determining ECM interval value EIR. Read TS data.

In step ST5, ECM is detected from the read TS data.
In step ST6, the reproduction data ECM interval value REI is calculated from the ECM time stamp values detected in succession, and the read range width determining ECM interval value EIR is calculated and updated based on this. This is replaced with the read range width determination ECM interval value EIR calculated before that).
In step ST7, the detected ECM is decrypted to extract the key.
In step ST8, the TS data is descrambled and demultiplexed using the extracted key to detect a sequence header and extract an I picture.
In step ST9, the reproduction data I picture interval value RGI is calculated from the detected time stamp value of the sequence header. Further, based on this, the jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value GIR are calculated. Is calculated and updated (replaced and stored with the jump destination determination I picture interval value GIJ and readout region determination I picture interval value GIR calculated before that).
In step ST10, the next read start position (jump destination) is determined using the jump destination determination I picture interval value GIJ calculated in step ST9. In this example, since the speed is 6 times, that is, N = 6, as shown in FIG. 6, the jump is made to the start position IP (n) of the first I picture in the current read range RR (n). The jump destination (the head position of the next read range RR (n + 1)) RS (n + 1) is determined to be 5.5 times (N-0.5) times the I-picture interval value GIJ for destination determination = DJ. The width of the read range RR (n + 1) is twice the larger of the read range width determination ECM interval value EIR or the read range width determination I picture interval value GIR, but in FIG. It is illustrated as being twice the picture interval value GIR (DGI). In FIG. 6, the reproduction data I picture interval value is indicated by the symbol RGI.

  After the read start position is determined in step ST10, it moves (jumps) to the next read start position in step ST11 and returns to step ST2.

  For example, in FIG. 6, since the I picture is intermittently read out every 6 GOPs and displayed for 0.5 seconds, special reproduction at 6 × speed is performed. In addition, when data is read intermittently, the amount of data read is about 1/3 of the total data read. Thus, in the method of the present invention, the higher the playback speed (multiple speed), the smaller the amount of reading from the storage medium 5 can be, and the burden on the storage medium control unit 4 is reduced.

  As described above, even when the TS is stored in a scrambled state, special reproduction can be performed without performing any special processing at the time of transmission or storage.

In the above example, the ECM interval estimator 7 outputs the read range width determining ECM interval value EIR (the read range width determining ECM interval value EIR is larger than the read range width determining I picture interval value GIR). In this case, the storage medium control unit 4 calculates the read range width by calculating twice the read range width determination ECM interval value EIR. Instead of this, the ECM interval estimation unit 7 In addition to the ECM interval value EIR for determining the reading range width, the standard deviation of the past predetermined number of reproduction data ECM interval values REI, for example, L (L is an integer of 1 or more) is calculated and output, and the storage medium control unit 4 may be a reading range width obtained by calculating a predetermined number (M) times the standard deviation, for example, 3 times and adding this to the reading range width determining ECM interval value EIR. . In this case, as the read range width determination ECM interval value EIR, a moving average value or a weighted average value may be used.
If the value obtained by adding three times the standard deviation is used as the readout range, when the ECM interval is Gaussian distributed, the probability that two or more ECMs are included in the readout range is about 99.7%. It becomes. Note that the standard deviation of the moving average value may be obtained instead of the reproduction data ECM interval value REI.

The same applies to the I picture interval. That is, in the above-described embodiment, the I picture interval estimation unit 17 outputs the reading range width determining I picture interval value GIR (the reading range width determining I picture interval is larger than the reading range width determining ECM interval value EIR). When the value GIR is larger, the storage medium control unit 4 calculates the read range width by calculating twice the read range width determining I picture interval value GIR. In addition to the I picture interval value GIR for determining the reading range width, the I picture interval estimation unit 17 calculates the standard deviation of the past predetermined number of reproduction data I picture interval values RGI, for example, L (L is an integer of 1 or more). Obtained by calculating and outputting, and the storage medium control unit 4 calculates a predetermined number (M) times, for example, 3 times the standard deviation, and adds this to the I-picture interval value GIR for reading range width determination. The value It may be in the range tentered. In this case, as the read range width determining I picture interval value GIR, a moving average value or a weighted average value may be used.
If the value obtained by adding three times the standard deviation is used as the readout range, if the interval between I pictures is Gaussian, the probability that two or more I pictures are included in the readout range is approximately 99.99. 7%. Note that the standard deviation of the moving average value may be obtained instead of the reproduction data I picture interval value RGI.

  In Embodiment 1, the time stamp value is used to estimate the ECM interval and the I picture interval, and the ECM interval and the I picture interval can be estimated only by the time interval without depending on the data amount. When the amount of data to be read sometimes changes and the detection timing of ECM and I picture does not change much, the positions of ECM and I picture can be estimated appropriately and special reproduction can be performed.

Embodiment 2. FIG.
FIG. 7 is a block diagram showing a digital broadcast storage / playback apparatus according to the second embodiment. In FIG. 7, 1 is an antenna for receiving a digital broadcast, 2 is a demodulator that demodulates the received signal and outputs a TS, 3 is a time stamp adding unit that adds a time stamp to the demodulated TS, and 5 is a TS storage A storage medium 4 for storing TS in the storage medium 5 during storage and a TS for reading the TS from the storage medium 5 during playback; 15 a memory for temporarily storing data read from the storage medium 5 during playback; 14 Is a memory control unit that controls reading and writing to the memory, 6 is an ECM detection unit that detects ECM from TS data, 7 is an ECM interval estimation unit that calculates or estimates an ECM interval, and 8 is a scrambler for the read TS data. Descramble part to be solved, 9 is a demux part for separating descrambled TS data into image and audio data, and 16 is for extracting I picture A picture extracting unit, 12 is a decoding unit that decodes an image, audio data, or an I picture extracted from the I picture extracting unit to be converted into an image, and 13 is a display unit that displays the decoded image. Is an I picture interval estimation unit that calculates or estimates an interval of I pictures, 18 is a clock generator, and 20 is a reproduction processing unit that performs reproduction processing.
Also in the present embodiment, as in the first embodiment, the ECM interval value and the I picture interval value represented by the difference between the time stamp values are used.

At the time of storage, the digital broadcast is received by the antenna 1 as in the first embodiment.
The received signal is demodulated by the demodulator 2 and output as TS. The time stamp adding unit 3 uses the clock from the clock generator 18 to add a time stamp to the demodulated TS.
The storage medium control unit 4 stores the TS added with the time stamp in the storage medium 5.
At this time, a list associating the time stamp with the position on the storage medium 5 is stored in the storage medium 5 so that it can be read at high speed if the time stamp is known during reproduction.
As for the ECM, the received ECM may be stored as it is, or another ECM may be newly created and stored.

  The I picture detection unit 10 detects the MPEG sequence header from the image data output from the demux unit 9 and detects the I picture.

  During normal playback, TS data is read from the storage medium 5 and stored in the memory 15, and the memory controller 14 adds the TS from the memory 15 using the same clock from the clock generator 18 as that used for storage. Are read out in order according to the time stamp values. The read TS is input to the reproduction processing unit 20.

In the reproduction processing unit 20, the ECM detection unit 6 detects an ECM from the read TS, and decrypts the detected ECM cipher. When the ECM detection unit 6 detects an ECM, a time stamp value at that time is output and supplied to the ECM interval estimation unit 7. The TS read from the memory 15 is descrambled by the descrambling unit 8 based on the ECM decoded by the ECM detection unit 6.
The descrambled TS is separated into image data and audio data by the demax unit 9. The image data and audio data are decoded by the decoding unit 12 and output as images and audio. The image and sound output from the reproduction processing unit 20 are displayed on the display unit 13.

The ECM interval estimator 7 of the second embodiment is the same as the ECM interval estimator 7 of the first embodiment, and outputs a read range width determining ECM interval value EIR.
To do.

  The I picture interval estimation unit 17 of the second embodiment is the same as the I picture interval estimation unit 17 of the first embodiment, and uses the jump destination determination I picture interval value GIJ and the read range width determination I picture interval value GIR. Output.

  Here, the special reproduction method according to the second embodiment will be described. The processing operation in the reproduction processing unit 20 when read from the storage medium 5 by the storage medium control unit 4 during special reproduction is the same as that during normal reproduction. That is, TS data of the storage medium 5 is temporarily stored in the memory 15, and TS data is read from the memory 15. When TS data read from the storage medium 5 is stored in the memory 15, it is desirable to store as much data as possible in the memory 15 in order to reduce the processing of the storage medium control unit 4. For example, in the case of digital broadcasting with a bit rate of 24 Mbps (3 Mbytes / s), if the amount read from the storage medium 5 at a time is 100 Mbytes, data of at least 30 seconds or more will be written in the memory 15 and the storage medium control The processing of the unit 4 can be reduced.

When the ECM detection unit 6 detects an ECM from the read TS data, the descrambling unit 8 descrambles the read TS data using a key extracted by decrypting the ECM. The descrambled TS data is separated into image and audio data by the demax unit 9, and the I picture extraction unit 16 detects the MPEG sequence header from the image data output from the demax unit 9, and extracts the I picture. The extracted I picture is decoded by the decoding unit 12 and displayed on the display unit 13 for a certain period.
The I picture detection unit 10 detects a sequence header from the image data output from the demux unit 9.

The ECM interval estimation unit 7 receives the ECM time stamp value in the reproduction data detected by the ECM detection unit 6 and calculates the ECM interval value EIR for reading range width determination.
The I picture interval estimation unit 17 receives the time stamp value of the I picture in the reproduction data detected by the I picture detection unit 10, and receives the jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value. GIR is calculated.

  The storage medium control unit 4 compares the read range width determination ECM interval value EIR with the read range width determination I picture interval value GIR, and if the read range width determination ECM interval value EIR is larger. As shown in FIG. 4A, memory control is performed on data included in a range (DEI) twice or larger than the ECM interval value EIR for reading range width determination so as to include at least two ECMs. The data is read from the memory 15 by the unit 14. On the other hand, when the reading range width determining I picture interval value GIR is larger, as shown in FIG. 4B, the reading range width determining I picture interval value GIR includes at least the head of two I pictures. TS data included in a range twice (DGI) or larger than that is read from the memory 15 by the memory control unit 14.

  At this time, special reproduction is performed by skipping the I picture outside the reading area in the memory 15 and reading only the I picture in the reading area.

FIG. 8 is a flowchart showing a procedure for reading TS data from the storage medium 5 during special reproduction. In FIG. 8, the same reference numerals as those in FIG. 5 denote the same steps. Here, it is assumed that special playback is 6 × playback (N = 6 for N × playback).
First, when special reproduction is started in step ST1, data is read from the storage medium 5 and stored in the memory 15 in step ST21. At this time, the amount of data to be stored is sufficiently large with respect to 1 GOP.
In step ST2, the read range width determining ECM interval value EIR (represented by the difference between the time stamp values) is compared with the read range width determining I picture interval value GIR.
When the reading range width determining I picture interval value GIR (expressed by the difference in time stamp values) is larger, the process proceeds to step ST22, and as shown in FIG. 4B, the reading range width determining I picture interval value TS data included in a range more than twice GIR is read from the memory 15. On the other hand, if the read range width determining ECM interval value EIR is larger, the process proceeds to step ST23, and as shown in FIG. 4A, the read range width determining ECM interval value EIR is included in a range that is twice or more the read range width determining ECM interval value EIR. TS data is read from the memory 15.

  At this time, the jump destination on the storage medium 5, that is, the start position of the read area is specified by the difference in the time stamp values up to the jump destination.

  In step ST24, it is determined whether or not the end of the data stored in the memory 15 has been read. If the end of the data has been read, the process proceeds to step ST25 where the next data is read from the storage medium 5 and stored in the memory 15. Reading from 15 is resumed.

In step ST5, ECM is detected from the read TS data.
In step ST6, the reproduction data ECM interval value REI is calculated from the ECM time stamp values detected in succession, and the read range width determining ECM interval value EIR is calculated and updated based on this. .
In step ST7, the detected ECM is decrypted to extract the key.
In step ST8, the TS data is descrambled and demultiplexed using the extracted key to detect a sequence header and extract an I picture.
In step ST9, the reproduction data I picture interval value RGI is calculated from the detected time stamp value of the sequence header. Based on this, the jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value GIR are calculated. Is calculated and updated.
In step ST10, the next read start position (jump destination) is determined using the jump destination determination I picture interval value GIJ calculated in step ST9.

  At this time, the interval from the beginning to the end of the reading area on the storage medium 5 is specified by the difference in the time stamp value indicating the reading range width.

  After the determination of the read start position in step ST10, in step ST26, it moves (jumps) to the next read start position in the memory 15. At this time, it is determined whether or not the end of the data stored in the memory 15 has been read (that is, whether or not the next read start is not in the memory 15), and when the end is read, the process proceeds to step ST27 and the next data is stored in the storage medium. 5 is read out and stored in the memory 15, and then moved (jumps) to the next reading start position in the memory 15. When moving to the next reading start position, the process returns to step ST2.

  Similar to the first embodiment, the second embodiment also uses the time stamp value to estimate the ECM interval and the I picture interval, so that the ECM interval and the I picture interval can be set only by the time interval without depending on the data amount. When the amount of data read at the time of reproduction changes and the detection timing of ECM and I picture does not change much, the positions of ECM and I picture can be estimated appropriately, and special reproduction can be performed. .

  Further, once the data from the storage medium 5 is moved to the memory as in the second embodiment, reading is performed at the time of special reproduction in the memory, and other processing is performed by the storage medium control unit at the time of special reproduction. It becomes possible. In other words, the processing of the storage medium control unit can be reduced by using the memory, and special reproduction can be performed even when there are many processes of the storage medium control unit that simultaneously reproduce multiple channels.

Embodiment 3 FIG.
FIG. 9 is a block diagram showing a digital broadcast storage / playback apparatus according to the third embodiment. In FIG. 9, 1 is an antenna for receiving a digital broadcast, 2 is a demodulator for demodulating the received signal, and outputs a TS, 3 is a time stamp adding unit for adding a time stamp to the demodulated TS, and 5 is for accumulating TS. The storage medium 4 stores the TS in the storage medium 5 at the time of storage and reads the TS from the storage medium 5 at the time of playback, the ECM detection unit 6 detects the ECM from the TS data, and 27 calculates the ECM interval. To ECM interval estimation unit for estimation, 8 is a descrambling unit for unscrambling the read TS data, 9 is a demux unit for separating the descrambled TS data into image and audio data, and 16 is an I picture for extracting an I picture The extraction unit 12 decodes an image, audio data input from the demax unit, or an I picture extracted from the I picture extraction unit. 13 is a display unit that displays the decoded image, 37 is an I picture interval estimation unit that calculates or estimates the interval of I pictures, 18 is a clock generator, and 20 performs a reproduction process. It is a reproduction processing unit.
In the present embodiment, ECM interval values and I picture interval values represented by the number of TSs are used.

At the time of storage, the digital broadcast is received by the antenna 1 as in the first and second embodiments.
The received signal is demodulated by the demodulator 2 and output as TS. The time stamp adding unit 3 uses the clock from the clock generator 18 to add a time stamp to the demodulated TS.
The storage medium control unit 4 stores the TS added with the time stamp in the storage medium 5.
As for the ECM, the received ECM may be stored as it is, or another ECM may be newly created and stored.

  The I picture detection unit 10 detects the MPEG sequence header from the image data output from the demux unit 9 and detects the I picture.

  During normal playback, as in the first embodiment, the storage medium control unit 4 causes the TS from the storage medium 5 to use the same clock from the clock generator 18 as that during storage according to the value of the added time stamp. Reads in order. The read TS is input to the reproduction processing unit 20.

In the reproduction processing unit 20, the ECM detection unit 6 detects an ECM from the read TS, and decrypts the detected ECM cipher. The TS read from the storage medium 5 is descrambled by the descrambling unit 8 by the ECM decoded by the ECM detection unit 6.
The descrambled TS is separated into image data and audio data by the demax unit 9. The image data and audio data are decoded by the decoding unit 12 and output as images and audio. The image and sound output from the reproduction processing unit 20 are displayed on the display unit 13.

  The ECM interval estimator 27 counts the number of TS between one ECM and the next ECM in the reproduction data detected by the ECM detector 6 and reads the ECM interval value for determining the read range represented by the number of TSs. EIR is calculated.

FIG. 10 is a block diagram showing a configuration of the ECM interval estimation unit 27 used in the third embodiment. The illustrated ECM interval estimation unit 27 includes an ECMTS count unit 24 and an ECM estimation calculation unit 25.
The ECMTS count unit 24 counts the number of TSs read between two ECMs detected in succession by the ECM detection unit 6 in the reproduction data (hereinafter also referred to as the ECM interval TS number), and this count value is calculated. The reproduction data ECM interval value REI is output as reproduction data ECM interval value REI.
The ECM estimation calculation unit 25 serves as a read area determination ECM interval value calculation means for obtaining a read range width determination ECM interval value EIR based on one or a plurality of reproduction data ECM interval values REI output from the ECMTS count unit 24. It is used.

  As in the first and second embodiments, the reproduction data ECM interval value REI itself, the average value, the maximum value, and the like detected by the ECM detection unit 6 are obtained as the ECM interval value EIR for reading range width determination.

  The I picture interval estimation unit 37 counts the number of TS between one I picture (start position) in the reproduction data and the next I picture (start position) detected by the I picture detection unit 10, The jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value GIR represented by the TS number are calculated.

FIG. 11 is a block diagram showing a configuration of the I picture interval estimation unit 37 in the third embodiment. The illustrated I picture interval estimation unit 37 includes an I picture TS count unit 19 and an I picture estimation calculation unit 21.
The I picture TS count unit 19 counts the number of TSs read between the sequence headers at the head of two I pictures detected in succession by the I picture detection unit 10 in the reproduction data. This is used as reproduction data I picture interval value detection means for outputting a value as reproduction data I picture interval value RGI represented by the number of TSs.
The I picture estimation calculation unit 21 uses the jump destination determination I picture interval value GIJ and the read range width determination I picture based on one or more reproduction data I picture interval values RGI output from the I picture TS count unit 19. This is used as a read area determination I picture interval value calculation means for calculating the interval value GIR.

  As in the first and second embodiments, the reproduction data I picture interval value RGI itself, the average value thereof, etc. detected by the I picture TS count unit 19 are obtained as the jump destination determining I picture interval value GIJ and reproduced. The data I picture interval value RGI itself, its average value, maximum value, etc. are obtained as the read range width determining I picture interval value GIR.

Here, the operation during special reproduction in the third embodiment will be described. The processing operation in the reproduction processing unit 20 when read from the storage medium 5 by the storage medium control unit 4 during special reproduction is the same as that during normal reproduction. That is, when the ECM detection unit 6 detects ECM from the read TS data, the descrambling unit 8 descrambles the read TS data by using the key extracted by decrypting the ECM. The descrambled TS data is separated into image and audio data by the demax unit 9, and the I picture extraction unit 16 detects the MPEG sequence header from the image data output from the demax unit 9, and extracts the I picture. The extracted I picture is decoded by the decoding unit 12 and displayed on the display unit 13 for a certain period.
The I picture detecting unit 10 detects an MPEG sequence header from the image data output from the demux unit 9 and detects an I picture.

The ECM interval estimation unit 27 calculates a read range width determination ECM interval value EIR from the number of TSs between the ECMs in the reproduction data detected by the ECM detection unit 6 one after the other.
The I picture interval estimation unit 37 calculates the jump destination determining I picture interval value GIJ and the reading range from the TS numbers between the sequence headers of the I picture in the reproduction data detected by the I picture detection unit 10 one after the other. The width determining I picture interval value GIR is calculated.

  The storage medium control unit 4 compares the read range width determination ECM interval value EIR with the read range width determination I picture interval value GIR, and if the read range width determination ECM interval value EIR is larger. As shown in FIG. 4A, the storage medium stores data included in a range (DEI) twice or larger than the ECM interval value EIR for reading range width determination so as to include at least two ECMs. Read by the control unit 4. When the read range width determining I picture interval value GIR is larger, as shown in FIG. 4B, the read range width determining I picture interval value GIR includes at least the head of two I pictures. The storage medium control unit 4 reads out TS data included in a range twice (DGI) or a range larger than that.

  At this time, special reproduction is performed by skipping the I picture outside the reading area in the storage medium 5 and reading only the I picture in the reading area.

  At this time, the jump destination on the storage medium 5, that is, the start position of the read area is specified by multiplying the TS number up to the jump destination by the number of TS bytes (188 bytes + time stamp).

FIG. 12 is a flowchart showing a procedure for reading TS data from the storage medium 5 during special reproduction. Here, it is assumed that special playback is 6 × playback (N = 6 for N × playback). 12, the same reference numerals as those in FIGS. 5 and 8 denote the same steps.
First, when special reproduction is started in step ST1, in step ST31, an ECM interval value EIR for reading range width determination (expressed by TS number) and an I picture interval value for reading range width determination GIR (expressed by TS number). To be compared).
When the read range width determining I picture interval value GIR is larger, the process proceeds to step ST32, and as shown in FIG. 4B, the read range width determining I picture interval value GIR is included in a range that is twice or more the read range width determining I picture interval value GIR. Read TS data. On the other hand, if the read range width determining ECM interval value EIR is larger, the process proceeds to step ST33, and as shown in FIG. 4A, the read range width determining ECM interval value EIR is included in a range that is twice or more the read range width determining ECM interval value EIR. Read TS data.
At this time, the interval from the beginning to the end of the read area on the storage medium 5 is specified by multiplying the TS number indicating the read range width by the number of TS bytes (188 bytes + time stamp).

In step ST5, ECM is detected from the read TS data.
In step ST34, the count value of the number of TSs between the ECMs detected before and after is obtained as the reproduction data ECM interval value REI, and further, based on this, the read range width determining ECM interval value EIR is calculated. Update.
In step ST7, the detected ECM is decrypted to extract the key.
In step ST8, the TS data is descrambled and demultiplexed using the extracted key to detect a sequence header and extract an I picture.
In step ST35, the count value of the TS number between the sequence headers at the head of the I picture detected in succession is obtained as the reproduction data I picture interval value RGI, and based on this, the jump destination determining I picture interval value is obtained. GIJ and read range width determination I picture interval value GIR are calculated and updated.
In step ST36, the next read start position (jump destination) is determined using the jump destination determination I picture interval value GIJ calculated in step ST35. In this example, since the speed is 6 times, that is, N = 6, as shown in FIG. 6, the jump destination determination I is performed with respect to the start position IP (n) of the first I picture in the current read range. The jump destination (next reading start position) RS (n + 1) is determined to be 5.5 times ((N−0.5) times) the picture interval value GIJ.
After the read start position is determined in step ST36, it moves (jumps) to the next read start position in step ST11 and returns to step ST31.

  As described above, the ECM interval and the I picture interval are estimated using the TS number (reading range width determining ECM interval value EIR represented by the TS number, reading range width determining I picture interval value GIR, jump destination determination (The jump destination and the read range width are determined using the I picture interval value GIJ for use), so that the detection timing of ECM and I picture changes between I pictures or between ECMs, and the amount of image data is reduced. When there is little change, there is an effect that the position of the ECM or I picture can be estimated appropriately and special reproduction can be performed.

  Instead of determining the jump destination and read range width using the ECM interval value and I picture interval value represented by the number of TSs, if the address values on the storage medium are continuous, the address value difference The jump destination and the read range width may be determined using the ECM interval value and the I picture interval value represented by In this case, a difference in address value between ECMs and between I pictures is calculated.

Embodiment 4 FIG.
FIG. 13 is a block diagram showing a digital broadcast storage / playback apparatus according to the fourth embodiment. In FIG. 13, 1 is an antenna that receives a digital broadcast, 2 is a demodulator that demodulates the received signal and outputs a TS, 3 is a time stamp adder that adds a time stamp to the demodulated TS, and 5 is a TS. A storage medium 4 for storing TS in the storage medium 5 during storage and a TS for reading the TS from the storage medium 5 during playback; 15 a memory for temporarily storing data read from the storage medium 5 during playback; 14 Is a memory control unit that controls reading and writing to the memory, 6 is an ECM detection unit that detects ECM from TS data, 27 is an ECM interval estimation unit that calculates or estimates an ECM interval, and 8 is a scrambler for the read TS data. The descrambling part to be solved, 9 is the demuxing part that separates the descrambled TS data into images and audio data, and 16 is the I picture I picture extracting unit 12, a decoding unit 12 for decoding an image input from the demux unit, audio data or an I picture extracted by the I picture extracting unit, and a display unit 13 for displaying the decoded image , 37 is an I picture interval estimation unit that calculates or estimates the interval of I pictures, 18 is a clock generator, and 20 is a reproduction processing unit that performs reproduction processing.
Also in the present embodiment, as in the third embodiment, the ECM interval value and the I picture interval value are represented by the number of TSs.

At the time of storage, the digital broadcast is received by the antenna 1 as in the first, second, and third embodiments. The received signal is demodulated by the demodulator 2 and output as TS. The time stamp adding unit 3 uses the clock from the clock generator 18 to add a time stamp to the demodulated TS.
The storage medium control unit 4 stores the TS added with the time stamp in the storage medium 5.
As for the ECM, the received ECM may be stored as it is, or another ECM may be newly created and stored.

  The I picture detection unit 10 detects the MPEG sequence header from the image data output from the demux unit 9 and detects the I picture.

  During normal playback, TS data is read from the storage medium 5 and stored in the memory 15 as in the second embodiment, and the memory controller 14 causes the TS from the memory 15 to be stored from the same clock generator 18 as that during storage. Are read out in order according to the value of the added time stamp. The read TS is input to the reproduction processing unit 20.

In the reproduction processing unit 20, the ECM detection unit 6 detects an ECM from the read TS, and decrypts the detected ECM cipher. The TS read from the memory 15 is descrambled by the descrambling unit 8 based on the ECM decoded by the ECM detection unit 6.
The descrambled TS is separated into image data and audio data by the demax unit 9. The image data and audio data are decoded by the decoding unit 12 and output as images and audio. The image and sound output from the reproduction processing unit 20 are displayed on the display unit 13.

The ECM interval estimator 27 of the fourth embodiment is the same as the ECM interval estimator 27 of the third embodiment, and outputs a read range width determining ECM interval value EIR.
To do.

  The I picture interval estimation unit 37 of the fourth embodiment is the same as the I picture interval estimation unit 37 of the third embodiment, and uses the jump destination determination I picture interval value GIJ and the read range width determination I picture interval value GIR. Output.

  Here, the special reproduction method according to the fourth embodiment will be described. The processing operation in the reproduction processing unit 20 when read from the storage medium 5 by the storage medium control unit 4 during special reproduction is the same as that during normal reproduction. That is, TS data of the storage medium 5 is temporarily stored in the memory 15, and TS data is read from the memory 15. When TS data is stored in the memory 15 from the storage medium 5, it is desirable to store as much data as possible from the storage medium 5 in the memory 15 in order to reduce the processing of the storage medium control unit 4. For example, if data having a capacity obtained by multiplying the number of TS corresponding to the I picture interval by 100 times the number of TS bytes (188 bytes + time stamp) is stored, data of about 100 GOP is stored. The processing of the unit 4 can be reduced.

When the ECM detection unit 6 detects an ECM from the read TS data, the descrambling unit 8 descrambles the read TS data using a key extracted by decrypting the ECM. The descrambled TS data is separated into image and audio data by the demax unit 9, and the I picture extraction unit 16 detects the MPEG sequence header from the image data output from the demax unit 9, and extracts the I picture. The extracted I picture is decoded by the decoding unit 12 and displayed on the display unit 13 for a certain period.
The I picture detection unit 10 detects a sequence header from the image data output from the demux unit 9.

The ECM interval estimator 27 counts the number of TS between one ECM and the next ECM in the reproduction data detected by the ECM detector 6 and reads the ECM interval value for determining the read range represented by the number of TSs. EIR is calculated.
The I picture interval estimation unit 37 counts the number of TS between one I picture (start position) in the reproduction data and the next I picture (start position) detected by the I picture detection unit 10, The jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value GIR represented by the TS number are calculated.

  The storage medium control unit 4 compares the read range width determination ECM interval value EIR with the read range width determination I picture interval value GIR, and if the read range width determination ECM interval value EIR is larger. As shown in FIG. 4A, memory control is performed on data included in a range (DEI) twice or larger than the ECM interval value EIR for reading range width determination so as to include at least two ECMs. The data is read from the memory 15 by the unit 14. On the other hand, when the reading range width determining I picture interval value GIR is larger, as shown in FIG. 4B, the reading range width determining I picture interval value GIR includes at least the head of two I pictures. The memory control unit 14 reads out TS data included in a range (DGI) that is twice the range (DGI) or a range larger than that.

  At this time, special reproduction is performed by skipping the I picture outside the reading area in the memory 15 and reading only the I picture in the reading area.

  At this time, the jump interval specifies the position (jump destination) on the storage medium 5 by multiplying the TS number to be jumped by the number of TS bytes (188 bytes + time stamp).

FIG. 14 is a flowchart showing a procedure for reading TS data from the storage medium 5 during special reproduction. Here, it is assumed that special playback is 6 × playback (N = 6 for N × playback). 14, the same reference numerals as those in FIGS. 5, 8, and 12 denote the same steps. Here, it is assumed that special playback is 6 × playback (N = 6 for N × playback).
First, when special reproduction is started in step ST1, data is read from the storage medium 5 and stored in the memory 15 in step ST21. At this time, the amount of data to be stored is sufficiently large with respect to 1 GOP.
In step ST31, the read range width determining ECM interval value EIR (expressed by the number of TSs) is compared with the read range width determining I picture interval value GIR (expressed by the number of TSs).
When the read range width determining I picture interval value GIR is larger, the process proceeds to step ST42, and as shown in FIG. 4B, the read range width determining I picture interval value GIR is included in a range that is twice or more the read range width determining I picture interval value GIR. TS data is read from the memory 15. On the other hand, if the read range width determining ECM interval value EIR is larger, the process proceeds to step ST43, and as shown in FIG. 4A, the read range width determining ECM interval value EIR is included in a range that is twice or more the read range width determining ECM interval value EIR. TS data is read from the memory 15.
At this time, the interval from the beginning to the end of the read area on the storage medium 5 is specified by multiplying the TS number indicating the read range width by the number of TS bytes (188 bytes + time stamp).

  In step ST24, it is determined whether or not the end of the data stored in the memory 15 has been read. If the end of the data has been read, the process proceeds to step ST25 where the next data is read from the storage medium 5 and stored in the memory 15. Reading from 15 is resumed.

In step ST5, ECM is detected from the read TS data.
In step ST34, the count value of the number of TSs between the ECMs detected before and after is obtained as the reproduction data ECM interval value REI, and further, the read range width determining ECM interval value EIR is calculated based on these count values. Update.
In step ST7, the detected ECM is decrypted to extract the key.
In step ST8, the TS data is descrambled and demultiplexed using the extracted key to detect a sequence header and extract an I picture.
In step ST35, the count value of the TS number between the sequence headers at the head of the I picture detected in succession is obtained as the reproduction data I picture interval value RGI represented by the TS number, and based on this, The jump destination determining I picture interval value GIJ and the reading range width determining I picture interval value GIR are calculated and updated.
In step ST36, the reading start position of the next TS data is determined using the jump destination determining I picture interval value GIJ calculated in step ST35. In this example, since the speed is 6 times, that is, N = 6, as shown in FIG. 6, the jump destination determination I is performed with respect to the start position IP (n) of the first I picture in the current read range. The jump destination (next reading start position) RS (n + 1) is determined 5.5 times ((N−0.5) times) the picture interval value GIJ.
After the determination of the read start position in step ST36, in step ST26, it moves (jumps) to the next read start position in the memory 15. At this time, it is determined whether or not the end of the data stored in the memory 15 has been read (that is, whether or not the next read start is not in the memory 15), and when the end is read, the process proceeds to step ST27 and the next data is stored in the storage medium. 5 is read out and stored in the memory 15, and then moved (jumps) to the next reading start position in the memory 15. When moving to the next reading start position, the process returns to step ST31.

  In the fourth embodiment, as in the third embodiment, the ECM interval and the I picture interval are estimated using the TS number (read range width determining ECM interval value EIR represented by the TS number, read range width determining I). By determining the jump destination and the read range width using the picture interval value GIR and the jump destination determination I picture interval value GIJ), the timing of detection of ECM and I picture can be determined between I pictures or between ECMs. When the amount of image data changes and the amount of image data does not change much, the position of the ECM or I picture can be estimated appropriately, and special reproduction can be performed.

  Similar to the second embodiment, in the fourth embodiment, the data from the storage medium 5 is temporarily transferred to the memory, and the special reproduction is performed in the memory. It is possible to perform the process. In other words, the processing of the storage medium control unit can be reduced by using the memory, and special reproduction can be performed even when there are many processes of the storage medium control unit that simultaneously reproduce multiple channels.

1 is a block diagram illustrating a digital broadcast storage / playback apparatus according to Embodiment 1. FIG. 3 is a block diagram showing an ECM interval estimation unit in Embodiment 1. FIG. 6 is a diagram illustrating a difference in a reading method depending on a relationship between an ECM interval and an I picture interval in Embodiment 1. FIG. 3 is a block diagram showing an I picture interval estimation unit in Embodiment 1. FIG. 6 is a flowchart showing data reading at the time of special reproduction in Embodiment 1. FIG. 6 is a diagram illustrating an example at the time of special reproduction at 6 × speed in the first embodiment. FIG. 6 is a block diagram illustrating a digital broadcast storage / playback apparatus according to a second embodiment. FIG. FIG. 11 is a flowchart showing data reading at the time of special reproduction in the second embodiment. FIG. 10 is a block diagram illustrating a digital broadcast storage / playback apparatus according to a third embodiment. 10 is a block diagram showing an ECM interval estimation unit in Embodiment 3. FIG. 10 is a block diagram illustrating an I picture interval estimation unit in Embodiment 3. FIG. FIG. 10 is a flowchart showing data reading at the time of special reproduction in the third embodiment. FIG. 10 is a block diagram illustrating a digital broadcast storage / playback apparatus according to a fourth embodiment. FIG. 10 is a flowchart showing data reading during special playback in the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna, 2 Demodulation part, 3 Time stamp addition part, 4 Storage medium control part, 5 Storage medium, 6 ECM detection part, 7, 27 ECM interval estimation part, 8 Descramble part, 9 Demax part, 10 I picture detection part , 11 I picture time stamp calculation unit, 12 decoding unit, 13 display unit, 14 memory control unit, 15 memory, 16 I picture extraction unit, 17, 37 I picture interval estimation unit, 18 clock generator, 19 I picture TS count 20 playback processing unit, 21 I picture estimation calculation unit, 23 ECM time stamp calculation unit, 24 ECMTS count unit, 25 ECM estimation calculation unit.

Claims (15)

A device for storing and playing back digital broadcasts,
A storage medium for storing scrambled TS data;
ECM interval estimation means for calculating a read range width determining ECM interval value based on the ECM interval in the TS data read from the storage medium when reproducing the TS data stored in the storage medium;
When reproducing the TS data stored in the storage medium, based on the I picture interval in the TS data read from the storage medium, a read range width determining I picture interval value and a jump destination determining I picture interval I picture interval estimation means for calculating a value;
Based on the read range width determination ECM interval value calculated by the ECM interval estimation means, the read range width determination I picture interval value and the jump destination determination I picture interval value calculated by the I picture interval estimation means, Storage medium control means for determining a range in which TS data is intermittently read out during special reproduction,
A digital broadcast storage and reproduction apparatus comprising: reproduction processing means for receiving TS data read from the storage medium by the storage medium control means and decoding and outputting only I pictures. A memory for temporarily storing TS data read from the storage medium during reproduction;
The TS data read from the memory is supplied to the ECM interval estimation means, the I picture interval estimation means, and the reproduction processing means as TS data read from the storage medium. 2. The digital broadcast storage / playback apparatus according to 1.   The storage medium control means uses a larger predetermined number of the read range width determination ECM interval value and the read range width determination I picture interval value as a read range width in special reproduction. The digital broadcast storage / playback apparatus according to claim 1.   The digital broadcast storage / playback apparatus according to claim 1, wherein the storage medium control means determines a jump destination at the time of special playback based on the jump destination determination I picture interval value. The ECM interval estimation means includes:
Reproduction data ECM interval value detection means for detecting an ECM interval in TS data read from the storage medium as reproduction data ECM interval value;
Reading area determining ECM interval value calculating means for calculating the reading range width determining ECM interval value based on the reproduction data ECM interval value detected by the reproducing data ECM interval value detecting means;
The I picture interval estimation means includes:
Reproduction data I picture interval value detection means for detecting an interval of I pictures in TS data read from the storage medium as reproduction data I picture interval values;
A read area determination I picture interval value for calculating the read range width determination I picture interval value and jump destination determination I picture interval value based on the reproduction data ECM interval value detected by the reproduction data ECM interval value detection means The digital broadcast storage / playback apparatus according to claim 1, further comprising: an arithmetic unit. A time stamp adding means for adding a time stamp by inputting the scrambled TS data,
The storage medium stores the output of the time stamp adding means,
The reproduction data ECM interval value detecting means detects, as reproduction data ECM interval values, differences in ECM time stamp values detected in succession in the TS data read from the storage medium,
The reproduction data I picture interval value detection means detects a difference between time stamp values of I pictures detected in succession in the TS data read from the storage medium as reproduction data I picture interval values. 6. The digital broadcast storage and reproduction apparatus according to claim 5, wherein The reproduction data ECM interval value detection means counts the number of TSs between ECMs detected in succession in the TS data read from the storage medium, and outputs the count value as a reproduction data ECM interval value And
The reproduction data I picture interval value detection means counts the number of TSs between heads of I pictures detected in succession in the TS data read from the storage medium, and uses the count value as reproduction data ECM. The digital broadcast storage and reproduction apparatus according to claim 5, wherein the digital broadcast storage and reproduction apparatus outputs the interval value.   The read area determining ECM interval value calculating means calculates the moving average value of the past K pieces (K is an integer of 1 or more) of the reproduction data ECM interval values detected by the reproduction data ECM interval value detection means. 6. The digital broadcast storage / playback apparatus according to claim 5, wherein the digital broadcast storage / playback apparatus is calculated as an ECM interval value for width determination.   The read area determining ECM interval value calculating means sets the maximum value of the past K reproduction data ECM interval values (K is an integer of 1 or more) detected by the reproduction data ECM interval value detecting means as the read range width. 6. The digital broadcast storage / playback apparatus according to claim 5, wherein the digital broadcast storage / playback apparatus calculates the determination ECM interval value.   The read area determining ECM interval value calculating means calculates a weighted average value of the past K pieces of reproduction data ECM interval values (K is an integer of 1 or more) detected by the reproduction data ECM interval value detection means. 6. The digital broadcast storage / playback apparatus according to claim 5, wherein the digital broadcast storage / playback apparatus is calculated as an ECM interval value for width determination.   The read area determining ECM interval value calculating means is a moving average value or a weighted average value of the past K pieces of reproduction data ECM interval values (K is an integer of 1 or more) detected by the reproduction data ECM interval value detection means. Further, a result obtained by adding a predetermined number of times of the standard deviation of the past L pieces of reproduction data ECM interval values (L is an integer of 1 or more) is calculated as the read range width determining ECM interval value. The digital broadcast storage / playback apparatus according to claim 5.   The read area determining I picture interval value calculating means calculates a moving average value of the past K pieces of reproduction data I picture interval values detected by the reproduction data I picture interval value detecting means (K is an integer of 1 or more). 6. The digital broadcast storage / playback apparatus according to claim 5, wherein the read range width determination I picture interval value is calculated.   The read area determining I picture interval value calculation means calculates the maximum value of the past K reproduction data I picture interval values detected by the reproduction data I picture interval value detection means (K is an integer of 1 or more). 6. The digital broadcast storage and reproduction apparatus according to claim 5, wherein the digital broadcast storage and reproduction apparatus calculates the read range width determining I picture interval value.   The read area determining I picture interval value calculating means calculates a weighted average value of the past K pieces (K is an integer of 1 or more) of the reproduction data I picture interval values detected by the reproduction data I picture interval value detecting means. 6. The digital broadcast storage / playback apparatus according to claim 5, wherein the read range width determination I picture interval value is calculated.   The read area determining I picture interval value calculating means is a moving average value of the past K pieces of reproduction data I picture interval values detected by the reproduction data I picture interval value detecting means (K is an integer of 1 or more) or A result obtained by adding a predetermined number times the standard deviation of the past L reproduction data I picture interval values to the weighted average value (L is an integer equal to or greater than 1) is calculated as the read range width determining I picture interval value. 6. The digital broadcast storage and reproduction apparatus according to claim 5, wherein

Images