JP2000165784A - Data reproducing apparatus and data reproducing method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce cost by reducing memory capacity. A pack identification circuit identifies an encoding type of an input stream. The input stream is stored in the data buffer 5. The storage contents and storage addresses of the data buffer 5 are stored in the pointers 11 to 14 for each encoding type. The data transfer request from the decoders 7 and 8 is supplied from the read / write arbitration circuit 15 to the read / write control circuit 6, and the read / write control circuit 6
Reads out the corresponding packet from the data buffer 5 based on the information of the pointers 11 to 14 and
8 Thus, even when the stream buffer is omitted, the decoder can be performed while maintaining synchronization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus and a data reproducing method suitable for reproducing encoded data recorded on a DVD or a video CD.

[0002]

2. Description of the Related Art In recent years, digital processing of images has become widespread.
D (Digital Versatile Disc) has also been developed. DV
The television signal to be recorded on D is encoded by the MPEG system in consideration of a variable bit rate (hereinafter, referred to as VBR).

When the transmission path has a fixed bit rate, encoding is performed so that the amount of code per GOP (Group Of Picture) varies less. In addition, when the transmission rate is a variable bit rate (hereinafter, referred to as VBR), encoding is performed using characteristics of a transmission path so that a change in image quality is reduced. Therefore, in VBR, the bit rate of encoded data fluctuates remarkably for each scene.

[0004] As an apparatus for decoding a reproduction signal from a DVD, there is an "information recording medium and its recording apparatus and reproducing apparatus" disclosed by JP-A-9-282848.

According to the proposed reproducing apparatus, a reproduced signal recorded on a DVD disk is supplied to a decoder via a track buffer. The track buffer holds a reproduction signal from the disk and outputs it to the decoder in order to cancel the time required for disk access and the processing time required for error correction. For example, a track buffer having a capacity of 4 Mbits is used.

The reproduced signal is an MPEG2 program stream (PS), which is separated into video data and audio data by a stream separation circuit and supplied to a video decoder and an audio decoder. The generated code amount of the encoded data differs depending on the picture, and even the same picture differs depending on the picture type. Therefore,
In order to decode each picture in each decoder in real time, a stream buffer for absorbing the burstiness of the generated code amount is provided. Each data from the stream separation circuit is supplied to each decoder via each stream buffer.

[0007] Of the stream buffers, a VBV (Video Buffering Verifier) buffer required by a video decoder is defined, for example, in MPEG to have a capacity capable of holding data for about 30 frames in consideration of data arrangement and the like. A memory capacity of 2 Mbits or more is required, and the memory capacity is large.

[0008]

As described above, conventionally, D
In an apparatus for reproducing and decoding a television signal recorded on a VD, each decoder requires a stream buffer in addition to a track buffer, and the required memory capacity is extremely large and the cost is high. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a data reproducing apparatus and a data reproducing method which can reduce the cost by enabling the required memory capacity to be reduced. Aim.

[0010]

According to a first aspect of the present invention, there is provided a data reproducing apparatus, comprising: storage means for inputting and storing an input stream obtained by packetizing encoded data of a plurality of encoding types; Pointer means for storing information indicating a storage address of the storage means for each coding type of the stream; and reading out coded data of the corresponding coding type from the storage means based on the information stored by the pointer means. Decoding means for decoding at a decoding start time based on the input stream. The data reproducing method according to claim 4 of the present invention provides a method for decoding an input stream in which encoded data of a plurality of encoding types is packetized. A process for storing in a storage unit, and a pointer for storing information indicating a storage address of the storage unit for each encoding type of the input stream. And a process of reading encoded data of a corresponding encoding type from the storage unit based on the information stored in the pointer storage process and decoding the encoded data at a decoding start time based on the input stream. .

According to the first aspect of the present invention, the input stream is stored in the storage means. The pointer means stores information indicating a storage address of the storage means for each encoding type of the input stream. Using this information, the decoding means reads and decodes the coded data of the corresponding coding type among the data stored in the storage means.

According to a fourth aspect of the present invention, the input stream is stored in the storage means, and information indicating the storage address of the storage means is stored for each encoding type. Using this information, encoded data of the corresponding encoding type is read from the storage means and decoded.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a data reproducing apparatus according to the present invention.

According to the present embodiment, a data buffer having the same capacity as the track buffer is used in place of the track buffer and pointers are assigned to data to be stored in the data buffer, thereby enabling random access from the data buffer. , The stream buffer can be omitted.

The disk 1 is rotated at a predetermined rotational speed by a spindle motor (not shown). Pickup 2
Irradiates the track of the disk 1 with a laser beam to read out the compression-encoded digital data stored on the track. Tracking servo circuit 3
Is adapted to control the movement of the pickup 2 in the radial direction of the disk to perform tracking.

A stream similar to an MPEG2 program stream is recorded on a track of the disk 1, for example. In a DVD or the like, one pack of the MPEG2 program stream is composed of packets of the same type such as video and audio.

The digital data from the pickup 2 is supplied to a pack identification circuit 4. The pack identification circuit 4
The head of the pack is detected from the input stream, and the encoding type of the packet packed in each pack is detected. For example, in the case of MPEG, video packets, audio packets, and SCRs (SystemCl
ock Reference) packet. The SCR packet is inserted into the stream at a predetermined interval and serves as a time reference for the stream. In MPEG, as a time stamp for managing the time of the decoding / reproducing process,
PTS (Presentation Time Stamp) is defined.

The pack identification circuit 4 supplies a flag indicating the detected encoding type to the bus 10 and supplies packet data to the data buffer 5. Writing and reading of the data buffer 5 are controlled by a read / write control circuit 6, and the input packet data is written and read, for example, in packet units. The packet data from the data buffer 5 is supplied to a decoder 7 corresponding to each encoding type.
8 and the STC counter 9.

On the other hand, the flag from the pack identification circuit 4 is
Via a bus 10, the data is supplied to a read / write pointer 11, a decoder 7 read pointer 12, a decoder 8 read pointer 13, and an SCR read pointer 14. The read / write pointer 11 stores information indicating that writing or reading has been performed for each address of the data buffer 5. The decoder 7 read pointer 12 and the decoder 8 read pointer 13 store information on the address of the data buffer 5 from which the data was read from the decoders 7 and 8, respectively. The SCR read pointer 14 is a pointer required when reading an SCR packet.

The read / write control circuit 6 includes a pointer
In accordance with the information stored in 11 to 14, the data buffer 5
Is controlled to write and read. The read / write arbitration circuit 15 includes a read / write control circuit 6
Between the decoders 7, 8 and ST
The writing and reading of the C counter 9 are arbitrated. The read / write arbitration circuit 15 requests the read / write control circuit 6 to read data when a request signal req from each of the decoders 7, 8 and the STC counter 9 is given. Further, the read / write arbitration circuit 15 outputs a valid signal val and determines a decoder that permits the start of decoding.

The decoders 7 and 8 are decoders corresponding to the respective encoding types, and decode the input packets and output decoded outputs. STC counter 9
A count value is set based on the input SCR,
The decoding of the decoders 7 and 8 is controlled based on the count value. That is, when the STC count value matches the PTS included in the input stream, the decoders 7 and 8 decode the input stream and output a decoded output.

Next, the operation of the embodiment configured as described above will be described with reference to FIGS. FIG. 2 is an explanatory diagram for explaining the contents of the pointers 11 to 14, and FIGS. 2A to 2E show the contents of the pointers 11 to 14, respectively. FIGS. 3A and 3B are explanatory diagrams for explaining the operation of the data buffer 5. FIG. 3A shows the occupancy of the data buffer, and FIG. 3B shows the count value of the STC counter.

The disk 1 is rotated at a predetermined number of revolutions by a spindle motor (not shown), and the tracking of the pickup 2 is controlled by a tracking servo circuit 3 to read data recorded on the tracks of the disk 1. Now, it is assumed that a program stream encoded by, for example, the MPE 2 is recorded on the disk 1.

Assume that the decoder 7 decodes audio data, the decoder 8 decodes video data, and audio packets are represented by A0, A1,..., And video packets are represented by V0, V1, V2,. I do.

The digital data reproduced by the pickup 2 is supplied to a pack identification circuit 4. The pack identification circuit 4 detects the head of the pack and the encoding type of the packet packed therein. The stream data input to the pack identification circuit 4 is supplied to the data buffer 5 as it is. Now, audio packet A0, video packet V0, V1, audio packet A1,
It is assumed that the input stream is input to the pack identification circuit 4 in the order of the video packets V2, V3,..., Vm. The data buffer 5 sequentially stores the input streams in the order in which they are supplied, as shown in FIG. The symbols on the left side of the frame indicating the contents of the data buffer 5 in FIG. 2 are values corresponding to the addresses of the data buffer 5, and are assigned the same values in FIGS. 2 (a) to 2 (e). Each area of the data buffer 5 has a capacity of about 2 kbytes when storing packet data of the MPEG standard.

On the other hand, the pack identification circuit 4 outputs a flag indicating the coding type of each packet to the bus 10. The read / write control circuit 6 performs the
The data buffer 5 and the pointers 11 to 14 are controlled.
The read / write control circuit 6 writes each packet to the data buffer 5 in the order of input, and reads a logical value “1” indicating that writing to the data buffer 5 has been performed in response to writing to the data buffer 5. / Light pointer 11
(FIG. 2B).

The read / write control circuit 6 writes data to the decoder 7 data read pointer 12 for the decoder 7 and to the decoder 8 data read pointer 13 for the decoder 8 based on the flag. In the example of FIG. 2, the audio packet is stored at the addresses (0) and (3) of the data buffer 5, and the video packet is stored at the addresses (1, 2) and (4 to n). .., N are written in the decoder 8 data read pointer 13.

In the SCR read pointer 14, "1" is written when writing an SCR packet to the data buffer 5, and "0" is written when reading an SCR packet. SCR indicates the time when the bit stream arrives at the decoder, and PTS indicates the decoding start time. When the STC counter 9 controls the decoders 7 and 8 using these values, it is possible to synchronize streams of different encoding types, for example, video and audio encoded data decoding.

The STC counter 9 is controlled by the read / write arbitration circuit 15 to read the input stream from the data buffer 5 and extract the SCR in the input stream.
In this case, the read / write control circuit 6 sets “0” indicating that the number of streams read from the data buffer 5 has been read to the corresponding address of the SCR read pointer 14.

The fact that the SCR has been written to the data buffer 5 is indicated by the SCR read pointer 14,
The TC counter 9 can acquire the sequentially input SCR values in real time. The STC counter 9 sets the S
The decoding timing of the decoders 7 and 8 is defined by the STC count value based on the CR and the PTS.

To the data buffer 5, streams are sequentially input from the disk 1 so that overflow and underflow do not occur. When a predetermined amount of data is accumulated in the data buffer 5, the stored data is read by the read / write control circuit 6 and supplied to each of the decoders 7, 8. The PTS for each encoding type included in the streams input to the decoders 7 and 8 is ST
When the values match the C count value, the decoders 7 and 8 output a decode output via the decode.

The read / write arbitration circuit 15 instructs the read / write control circuit 6 to read data in response to a request signal req from the decoders 7, 8. The read / write control circuit 6 is controlled by the read / write arbitration circuit 15 to control reading so that the decoders 7 and 8 can perform decoding processing in real time of audio and video.

For example, it is assumed that audio data is decoded by the audio decoder 7. When a request from the read / write arbitration circuit 15 occurs, the read / write control circuit 6 reads the address of the data buffer 5 written in the data read pointer 12 of the decoder 7 in order, and reads the read address to the data buffer 5. Supply. FIG.
In the example of (c), the audio packet A0 written to the address (0) of the data buffer 5 is read out,
The voice packet A1 written at the address (3) is read.

In this case, the read / write control circuit 6
Writes "0" indicating that data has been read into the read / write pointer 11 for the address portion read from the data buffer 5. That is, the address (0, 3) of the read / write pointer 11 becomes “0”.

On the other hand, when video data is decoded by the video decoder 8, the read / write control circuit 6
Reads the address of the data buffer 5 written in the data read pointer 13 of the decoder 8 in order, and supplies the read address to the data buffer 5. FIG.
In the example of (d), the address (1,
Video packets V0 written in (2, 4, 5-n)
.. Are sequentially read.

In this case, similarly, the read / write control circuit 6 writes "0" indicating that data has been read into the read / write pointer 11 for the address portion read from the data buffer 5. That is, the address corresponding to the read / write pointer 11 becomes “0”.

As described above, by using the pointer,
Packets desired by the decoders 7 and 8 can be freely read from the data buffer 5. Also, each decoder 7,
8 reads the packet data from the discontinuous address of the data buffer 5, the read / write pointer
Since the address from which the data was read is determined by 11, the data can be read even when a new input stream is written to this address. That is, it is only necessary to write data to the address of the data buffer 5 corresponding to the address “0” of the read / write pointer 11.

Further, since the address of the data buffer 5 in which the encoded data has been written is stored in the read pointer corresponding to the decoder for each encoding type, the reading for each encoding type can be performed. It is possible.

Thus, even when a stream buffer such as a VBV buffer is not used, decoding can be performed while synchronizing with the STC counter.

Next, the capacity of the data buffer 5 will be described.

FIG. 3A shows the transition of the occupancy of the data buffer by taking the time on the horizontal axis and the occupancy of the data buffer on the vertical axis. The maximum value in FIG. 3A indicates the capacity of the data buffer 5. FIG. 3B shows the transition of the STC counter by taking the time on the horizontal axis and the STC count value on the vertical axis. FIG. 3 shows the relationship between the transition of the data amount in the data buffer and the STC counter when the decoder 7 performs decoding. Although FIG. 3 shows only video data, the data buffer occupancy of data of another encoding type such as audio data is extremely small and can be ignored compared to the occupancy of video data. Therefore, only the occupation amount of the video data needs to be considered as the capacity of the data buffer 5.

In the video stream, SCR0, SCR1
, SCR2, ... and PTS0, PTS1, PTS2,
Are sequentially inserted. As mentioned above,
.. Indicate the time when each packet arrives at the decoder, and PTS0, PTS1,... Indicate the time at which each decoder starts decoding and outputs.

At the start of reproduction of data from the disk 1, decoding is not performed, and the input stream is sequentially stored in the data buffer 5. Thereby, as shown in FIG. 3A, the occupancy of the data buffer 5 increases in accordance with the reproduction rate from the disk 1. Next, at the timing of PTS0, the decoder 7 starts decoding. In FIG. 3A, the time required for decoding is neglected, and the decoding reduces the data amount of the data buffer 5 by the decoded data amount during the time of PTS0 in FIG. 3A.

The decoded data is stored in the memory in the decoder, and is output according to the display timing.

Until the next decoding starts, the input stream is accumulated, and the occupancy of the data buffer 5 increases. When the data is accumulated to the full capacity of the data buffer 5, the reproduction from the disk 1 is stopped and the input to the data buffer 5 is stopped.

At the timing of PTS1, the next decoding is started in the decoder 7. As a result, the data is read from the data buffer 5 and the occupancy is reduced. Then, reproduction from the disk 1 is restarted, and accumulation of data in the data buffer 5 starts.

However, since the data supplied to the data buffer 5 is to be read from the rotating disk 1 by the pickup 2, it is necessary to move the pickup 2 to the reproduction position on the disk 1 after stopping the reproduction. (Hereinafter referred to as kickback time). That is, during this kickback time, data is not accumulated in the data buffer 5.

On the other hand, decoding in the decoder is performed in units of pictures, and the amount of data read from the data buffer 5 at one time differs for each picture. The stream buffer in the conventional example is defined by the capacity of the maximum data amount (maximum read data rate) read at a time in MPEG, for example. In other words, at the time of encoding, encoding is performed with the code amount suppressed to a value less than the capacity of the stream buffer per picture.

When the kickback time and the read at the maximum read data rate are performed simultaneously and repeatedly,
There is a possibility that the occupation amount of the data buffer 5 is reduced most and an underflow occurs. If the reproduction from the disk 1 is stopped, the data occupancy does not increase, so that there is no problem with overflow.

In FIG. 3A, the capacity of the data buffer 5 is set to twice the maximum amount of data read at one time, and reading at the maximum reading data rate is repeated three times continuously. The case where the kickback time is 1.5 times the decoding cycle is shown. PTS1, PTS
At the timing of 2, PTS3, reading from the data buffer 5 is performed at the maximum reading data rate. FIG.
Indicates a state in which no underflow occurs even in this case.

That is, the capacity of the track buffer 5 for preventing underflow is given by the following equation (1).

Track buffer capacity = (2Tk + tj + 4Te) × MAX_V0 (1) where Tk indicates a kickback time (rotation waiting time), tj indicates a track seek time, and Te indicates one ECC.
MAX_V0 indicates the maximum read data rate from the track buffer.

In practice, it is unlikely that reading with the maximum data amount is repeated three times in succession.
The capacity based on the expression is considered to be sufficient as the capacity of the data buffer 5.

That is, the data buffer having the same capacity as the track buffer in the conventional example can serve both functions of the track buffer and the stream buffer.

For example, Tk = 104.5, tj = 14
Assuming that 6, Te = 24 and MAX_V0 = 8 Mbps, a case where reproduction is performed from a DVD will be described.
As described above, the buffer occupancy of the video data is extremely large as compared with the buffer occupancy of the other data. Therefore, only the video data is considered without considering all the encoded data.

Under this condition, the expression (1) is 3.6 M bits. The actual hardware is 4Mbit DR
It is conceivable to use AM. When the data buffer 5 is full, the above expression (1) is satisfied. At this time, about 4M bits of data are stored in the data buffer. The data rate transmitted to the decoder 7 is 8M
bps. Video decoding may require a code amount of 2 Mbits per frame instantaneously,
Basically, data is decoded based on the input maximum data rate.

In consideration of the maximum transfer rate of a DVD, it is not considered that all frames are coded with a code amount of 2 Mbits. Generally, the next frame transferred at the maximum data rate is not considered. Is transferred at a data rate lower than the maximum data rate.

In other words, the video decoding is, on average, also MAX.
Since the data is decoded at 8 Mbps which is _V0,
In order for the video decoder to consume all the encoded data of a maximum of 4M bits stored in the data buffer 5, 4M bits are required.
A time of bit / 8 Mbps = 500 ms is required.

On the other hand, the time from when data is accumulated to the full capacity of the data buffer 5 until the next data is read from the disk 1 is calculated by substituting each value into the above equation (1).
Since the time is 51 ms, the data is read from the disk 1 before all the encoded data in the data buffer 5 is consumed, and the data buffer 5 does not underflow.

As described above, in this embodiment, the memory capacity can be reduced by deleting the stream buffer and using the data buffer having the same capacity as the track buffer so that the functions of the track buffer and the stream buffer are also used. Can be.

Incidentally, in the present embodiment, the function of the conventional stream buffer is achieved by the data buffer used in place of the track buffer. On the other hand, it is conceivable that the track buffer is omitted and the functions of the track buffer and the stream buffer are achieved by a buffer similar to the stream buffer.

Since the track buffer is omitted, it is necessary to add a track buffer function to a buffer similar to the stream buffer. In other words, it is necessary to provide a sufficient capacity so that the underflow does not occur in the time required for the disc jump or the like.

The data rate of the DVD stream is a maximum of 10.08M for all of video, audio and sub-picture.
bps. On the other hand, the maximum data rate of each encoded data is limited to 9.8 Mbps.

For example, assuming that the data rate of video data is 9.8 Mbps, the data rate allowed for other data is 0.28 Mbps. The capacity of the track buffer depends on the data rate of such a DVD stream. In the track buffer (or data buffer), these data are stored while being multiplexed, so that the capacity may be about 4M bits.

However, when each packet is divided and stored in each stream buffer, it is necessary to consider the case where each packet has the maximum data rate, and any buffer has a capacity of 4 Mbits. And the required memory capacity increases as compared with the case where the track buffer and the stream buffer are separately provided.

For this reason, in the present embodiment,
The stream buffer is omitted, and a data buffer is used instead of the track buffer.

FIG. 4 is a block diagram showing another embodiment of the present invention. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the pack identification circuit 4 is omitted, and an external HOST 21 supplies a flag indicating the encoding type.

The external HOST 21 sends a flag indicating the packet type onto the bus 10 if the encoding type of the data to be written into the data buffer 5 is known in advance. Also, when the decoders 7 and 8 read data from the data buffer 5, the HOST 21
Can control reading from the data buffer 5.

The embodiment configured as described above is adopted, for example, in an apparatus for reproducing a disk or the like on which audio encoded data defined by DVD audio and still picture encoded data are recorded. In this case, the packet of the still image data is reproduced first, and the data buffer 5
Is stored. Next, audio data packets are reproduced from the disk and decoded while being supplied to the data buffer 5. Further, during the decoding of the audio data, the still image data stored in the data buffer 5 is transferred to the video decoder for each packet specified by the HOST 21 and decoded.

As described above, also in the present embodiment, the same effect as in the embodiment of FIG. 1 can be obtained. In addition, when this embodiment is applied to the DVD audio standard, it is possible to easily realize, for example, displaying a still image while listening to audio.

FIG. 5 is a block diagram showing another embodiment of the present invention. 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, the writing to the buffer is executed by the processor 31 in a software manner.

The data RAM 32 is a work RAM and a data storage RAM. The processing processor 31 is, for example, a RISC
This is a general processor capable of performing software processing, such as a processor.
The instruction codes stored in M33 are sequentially interpreted and executed. Thereby, the processor 31 realizes the functions of the track buffer and the stream buffer for the input stream.

That is, in the present embodiment, the data buffer 5 and the pointers 11 to 14 in the embodiment of FIGS. 1 and 4 are replaced with a data RAM 32, and the processor 31 divides the area in the data RAM 32 to To achieve the buffer function. Further, the processor 31 also realizes the functions of the pack identification circuit 4, the read / write control circuit 6, and the read / write arbitration circuit 15 in the embodiments of FIGS.

Next, the operation of the embodiment configured as described above will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation of the embodiment. FIG.
Is described corresponding to the C language, but it is obvious that the description may be made in any language.

In FIG. 6, an array databuffer [] corresponds to the data buffer 5 in the embodiment of FIGS. 1 and 4, and an array read_write_point [] is a read / write pointer.
11 and the array dec1data_read_point []
It corresponds to the data read pointer 12, and the array dec2data_read_
point [] corresponds to the decoder 8 data read pointer 13, and the array scr_read_point [] corresponds to the SCR read pointer 14.

When the input stream is input, the processing processor 31 proceeds to step S1 in FIG.
Store in []. In this case, the processing processor
31 is array read_write_point [] and array scr_read_point
Write "1" in [].

Next, the processing processor 31 proceeds to step S2
, The type of encoding of each packet in the pack of the input stream is identified. If the input pack is a packet to be decoded by the decoder 7, the address ad0 at the time of writing to the array databuffer [] is written to the array dec1data_read_point [], and if the input pack is a packet to be decoded by the decoder 8 Is the array dec2
Write address ad0 when writing to array databuffer [] to data_read_point [].

When an output request is issued from the decoders 7, 8, the processor 31 executes an output process in step S3. That is, when an output request from the decoder 7 occurs, the packet in the array databuffer indicated by the address of the array dec1data_read_point [ad2] is read and output. In this case, “0” indicating that the data has been read is written to the array read_wreite_point [].

Similarly, when an output request from the decoder 8 occurs, a packet in the array databuffer indicated by the address of the array dec1data_read_point [ad3] is read and output, and also indicates that the data has been read to the array read_wreite_point []. Write "0". In the next step S4, the addresses ad0, ad1, ad2, and ad3 of each array are counted up, and the process returns to step S1.

As described above, in this embodiment, the data RAM having substantially the same capacity as the conventional track buffer is used.
, A track buffer and a stream buffer function can be realized by software processing.

[0081]

As described above, according to the present invention, the required memory capacity can be reduced, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a data reproducing apparatus according to the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the embodiment in FIG. 1;

FIG. 3 is an explanatory diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 4 is a block diagram showing another embodiment of the present invention.

FIG. 5 is a block diagram showing another embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation of the embodiment of FIG. 5;

[Explanation of symbols]

1 disk, 4 pack identification circuit, 5 data buffer, 6 read / write control circuit, 7, 8 decoder,
9 STC counter, 11 to 14 pointer, 15 read / write arbitration circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C052 AA02 AA17 AB03 AB04 BB02 CC06 CC11 DD04 5C053 FA24 FA27 GB37 HA33 JA07 JA24 KA04 KA19 KA24 LA06 5C059 KK08 MA00 SS13 UA05 UA32 UA34 UA36

Claims (4)

[Claims] A storage unit configured to receive and store an input stream in which encoded data of a plurality of encoding types is packetized; and store information indicating a storage address of the storage unit for each encoding type of the input stream. Pointer means for storing, and decoding means for reading coded data of a corresponding coding type from the storage means based on the information stored by the pointer means and decoding the coded data at a decoding start time based on the input stream. A data reproducing device characterized by the above-mentioned. 2. The pointer according to claim 1, wherein the encoding type of the input stream is notified to the pointer unit by means for detecting a packet identifier in the input stream or by an external instruction. Data playback device. 3. The decoding start time in the decoding means is determined by a decoding reference time obtained from the input stream and decoding start information multiplexed on the input stream, or is determined by an external instruction. The data reproducing apparatus according to claim 1, wherein: 4. A process of storing an input stream in which encoded data of a plurality of encoding types is packetized in a storage unit, and storing information indicating a storage address of the storage unit for each encoding type of the input stream. A pointer storing process for reading the encoded data of the corresponding encoding type from the storage unit based on the information stored in the pointer storing process, and decoding the encoded data at a decoding start time based on the input stream. A data reproducing method characterized by the following.