JPH11196374A - Coded signal recording and reproducing device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coded signal recording and reproducing device that conducts decoding and reproduction simultaneously especially while recording, in a device which codes a dynamic image and an audio signal and records them in a recording medium and reproduce them. SOLUTION: The device is constituted of a 1st buffer 3 that buffers a coded signal by a prescribed amount, a recording head 4 that records an output of the 1st buffer in a recording medium at a prescribed transmission rate, a reproduced data selection section 8 that selects which of a coded signal recorded by a recording head just precedingly or other coded signal having already been recorded, a reproduction head 7 that reproduces the recording signal, a 2nd buffer 9 that buffers the signal in a burst way at a prescribed transmission rate read by the reproduction head, to reproduce the coded signal in a reproduction time length, and a data read control section 10 that temporarily stops the reading from the recording medium according to a buffer occupancy rate of the coded signal stored in the 2nd buffer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing moving picture and audio signal encoded data on a recording medium, and more particularly to an encoded signal recording which enables simultaneous decoding and reproduction while recording. It relates to a playback device.

[0002]

2. Description of the Related Art A conventional encoded signal recording / reproducing apparatus encodes an image and a voice, buffers multiplexed data, and performs real-time recording / reproducing at a multiplexed rate.
An example of the configuration of the conventional device will be described below with reference to the drawings. In the encoded signal recording / reproducing apparatus shown in FIG. 3, an image is encoded by an image encoding unit 31V, and audio is encoded by an audio encoding unit 31A, and the data is multiplexed by a multiplexing unit 32. The multiplexed data is buffered in the buffer 33, smoothed to a predetermined transmission rate, and sent to the recording medium 35.

The recording medium 35 is recorded on the recording medium 35 with the recording / reproducing head 34R in a recording mode. The recording is recorded at the coding rate input to the buffer. For reproduction, the recording / reproducing head 34P is set to a reproducing mode from the recording medium 35, information is read out at an encoding rate, buffered in a buffer 36, and separated into coded image and audio data in a multiplex / separation unit 37. Each is decoded and reproduced by the image decoding unit 38V and the audio decoding unit 38A.

[0004]

In the prior art, when recording on a supplied recording medium, encoded data different from the recorded encoded data could not be reproduced. That is, since the recording medium is rotating at the same rate as the recorded encoding rate, the time spent for recording with one recording / reproducing head matches the encoding time, and the time spent for reproduction cannot be obtained. . Further, even when recording encoded data at a variable transfer rate, the recording medium rotates at the same rate as the maximum encoding rate of the encoded data. The period encoded at the maximum encoding rate coincided with the encoding time, and there was virtually no time spent for reproduction.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an encoded signal for recording and reproducing an encoded signal on a recording medium by a recording head and a reproducing head. A recording / reproducing apparatus, a first buffer for buffering the coded signal by a predetermined amount, a recording head for recording an output of the first buffer on the recording medium at a predetermined transmission rate, A reproduction data selection unit for selecting which of an encoded signal recorded immediately before by the head or another encoded signal already recorded is reproduced, and a recording area recorded immediately before the recording medium, or A reproducing head for reproducing a recording signal from another recorded coded signal recording area; and a buffer for reading out the buffer at the predetermined transmission rate by the reproducing head. A second buffer for reproducing an encoded signal with a reproduction time length, and a data reading control unit for temporarily suspending reading from the recording medium in accordance with a buffer occupancy of the encoded signal recorded in the second buffer. And more.

According to a second aspect of the present invention, there is provided an encoded signal recording / reproducing apparatus for recording / reproducing an encoded signal on a recording medium by a recording / reproducing head, wherein the encoded signal is buffered by a predetermined amount at a predetermined transmission rate. A first buffer to be ringed, and an output of the first buffer recorded on the recording medium at a transmission rate higher than the predetermined transmission rate;
At the time of reproduction, a recording / reproducing head for reproducing a recording signal from either a recording area recorded immediately before on the recording medium or another encoded signal recording area already recorded on the recording medium; A reproduction data selection unit for selecting whether to reproduce the coded signal recorded immediately before by the dual-purpose head or another coded signal already recorded, and the time during which the data is buffered in the first buffer. A second buffer for reading and buffering in bursts at a transmission rate higher than the predetermined transmission rate by the recording / reproducing head, and reproducing an encoded signal with a reproduction time length; And a data reading control unit for temporarily stopping reading from the recording medium in accordance with the buffer occupancy of the encoded signal.

According to a third aspect of the present invention, there is provided the encoded signal recording / reproducing apparatus according to the first or second aspect, wherein the recording medium is a readable / writable disk. .

According to a fourth aspect of the present invention, there is provided an encoded signal recording and reproducing method for recording and reproducing an encoded signal on a recording medium by a recording head and a reproducing head.
The encoded signal buffered by the buffer is recorded on the recording medium by the recording head at a predetermined transmission rate, and at the same time, the encoded signal recorded immediately before or another encoded signal already recorded Selected by a reproduction data selection unit, read out by the reproduction head in a burst at a first transmission rate, and recorded in a second buffer;
According to a coded signal recording / reproducing method, the reading of the recorded coded signal is temporarily suspended in accordance with the buffer occupancy, and the coded signal is reproduced from the second buffer with a reproduction time length.

According to a fifth aspect of the present invention, there is provided an encoded signal recording / reproducing method for recording / reproducing an encoded signal to / from a recording medium by a recording / reproducing head, wherein the first buffer buffers the predetermined amount at a predetermined transmission rate. A ring-encoded signal is recorded on the recording medium by a recording / reproducing head at a transmission rate higher than the predetermined transmission rate, and is encoded at a transmission rate higher than the predetermined transmission rate recorded immediately before. A signal or another coded signal that has already been recorded is selected by the reproduction data selection unit, and during the time that the signal is buffered in the first buffer, the data is transmitted by the recording / reproduction head faster than the predetermined transmission rate. The data is read out in bursts at a rate and recorded in the second buffer, and is read out according to the buffer occupancy of the recorded coded signal. It was temporarily stopped, and from the second buffer the encoded signal with the playback duration and the encoded signal recording reproducing method of reproducing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the coded signal recording / reproducing apparatus of the present invention will be described below with reference to the drawings. As an example of a coded signal recording medium used in the apparatus of the present invention, a RAM disk capable of recording and reproduction will be described below. An apparatus for reproducing while recording a supplied signal includes a recording / reproducing apparatus (hereinafter, referred to as a two-head system) having two heads, a recording head and a reproducing head, and one head for both recording and reproducing. There is a recording / reproducing device (hereinafter referred to as a one-head system).

First, an embodiment of a recording / reproducing apparatus (two-head system) using two heads, a recording head and a reproducing head, will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a recording / reproducing apparatus (two-head system) provided with two heads, a recording head and a reproducing head. In FIG. 1, an input image is an image encoding unit 1V
The input speech is encoded by the speech encoding unit 1A, and the data is multiplexed by the multiplexing unit 2.

The data multiplexed by the multiplexing unit 2 is buffered in a buffer memory (first buffer) 3. The multiplexed data is buffered at a first transmission rate Ra, and the first buffer 3 is filled to some extent (for example, 9
9%), a signal notifying the 99% sufficiency is transmitted from the buffer 3 to the data write control unit 5. When a signal indicating the sufficiency is supplied, the data write control unit 5 issues a write command to the recording head 4. Thereby, the data is smoothed to a predetermined rate and transmitted to the RAM disk recording medium 6. When the encoded data is fixed-rate encoding, the rate at which the data is smoothed substantially matches this encoding rate. That is, recording is performed at a rate that takes into account the format header specific to the recording medium in addition to the encoding rate. When the encoded data is variable-rate encoded, the rate at which the data is smoothed substantially matches the maximum rate of the encoded data. That is, recording is performed at a rate that takes into account a format header specific to the recording medium in addition to the maximum rate.

In the two-head type recording / reproducing apparatus, the recording rate of the RAM disk 6 as a recording medium is synchronized with the above-described rate (first transmission rate) Ra.
The recording head 4 uses the recording medium RA at that rate Ra.
It is recorded on the M disk 6. On the other hand, the reproducing head 7 independent of the recording head 4 shown in FIG. 1 reads information different from the information recorded immediately before by the recording head 4. This other information is information (data) already recorded in another recording area of this recording medium (disk) 6 by the recording head 4, for example. An area may be configured. One piece of data to be reproduced is selected from the reproduction data selecting section 8 and the information is transmitted to the reproducing head 7.

The reproducing head 7 reads the selected encoded data. If the encoded data is fixed rate encoded,
The reading rate substantially matches this encoding rate. Further, when the encoded data is variable-rate encoded, the readout rate is read at the maximum rate of the encoded data, so that the second buffer 9 immediately overflows. Therefore, the buffer 9 is filled to some extent (for example, 99
%), The reading from the recording medium 6 is temporarily interrupted (stopped).

For this purpose, a signal notifying that 99% is full is transmitted from the buffer 9 to the data reading control unit 10. When a signal indicating the sufficiency is supplied, the data reading control unit 10 issues a reading temporary stop command to the reproducing head 7. The reading suspension operation is achieved by continuing the skipping operation for returning the reproducing head 7 for one track until a reading start command is issued.

When the coded data from the buffer 9 is decoded and consumed at the second coding rate Rb, and the buffer fullness is reduced to some extent (for example, 25%), the buffer 9 notifies the buffer 9 that the fullness is 25%, for example. The signal is transmitted to the data reading control unit 10. When a signal indicating the sufficiency is supplied, the data reading control unit 10 issues a reading start command to the reading (reproduction) head 7.

The reading start operation can be achieved by canceling the operation of returning (skip) the reproducing head 7 for one track, which has been continued until then. When the program once recorded is operated only by reproduction, the reproduction is performed by using the reproducing head 7 at the encoding rate of the first transmission rate Ra as before. When the buffer 9 is filled to some extent (for example, 99%), the reading from the disk 6 as the recording medium is temporarily stopped. This operation is repeated. Decoding is continuously performed from the buffer 9 at the coding rate Rb. When the reproduction data selection unit 8 selects the encoded signal recorded immediately before, the reproduction operation of the reproduction head 7 is
Other reproducing operations are the same except that a recording area for reproducing a signal from the recording medium is different.

Next, the case of the one-head system of one embodiment of the coded signal recording / reproducing apparatus of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram of a one-head system according to an embodiment of the encoded signal recording / reproducing apparatus of the present invention.
In the one-head system (recording / reproducing head system), the RAM disk 26, which is a recording medium mounted on the coded signal recording / reproducing apparatus, has a recording rate that is at least twice as fast as the maximum coding rate of the coded signal. (Third transmission rate) Synchronize with Rc.

The data obtained by multiplexing the image signal of the image encoding unit 21V and the audio signal of the audio encoding unit 21A by the multiplexing unit 22 is buffered at a transmission rate (first transmission rate) Ra, When one buffer 23 is filled to some extent (for example, 99%), a signal notifying the 99% filling is transmitted from the buffer 23 to the data writing control unit 25. When a signal indicating the sufficiency is supplied, the data write control unit 25 issues a write command to the recording / reproducing head 24R. In that case, the recording / reproducing head 24R is set to the recording mode, and is recorded on the recording medium 26 at the third transmission rate Rc.

On the other hand, while the multiplexed data is buffered at the transmission rate (first transmission rate) Ra,
The recording / reproducing head 24P is switched to the reproducing mode,
Read the recorded information. The recording / reproducing head 24P switched to the reproducing mode reads information different from the information recorded in the recording mode. This other information is information data which has already been recorded in another recording area of this recording medium (disk) 26 by, for example, the recording / reproducing head 24R. May be configured. That is, one piece of data to be reproduced is selected and designated from the reproduced data selecting section 27, and the designated information is transmitted to the reproducing head 24P. The recording / reproducing head 24P switched to the reproducing mode reads another coded data selected and designated.

At the time of reading, since the data is read at the third transmission rate Rc which is at least twice as fast as the maximum coding rate of the coded signal, the second buffer 28 immediately overflows. Therefore, when the buffer 28 is filled to some extent (for example, 99%), the recording medium (disk) 26
Suspends reading from. Buffers 28 to 99
A signal notifying the% satisfaction is transmitted to the data reading control unit 29. When a signal indicating the sufficiency is supplied, the data reading control unit 29 issues a reading temporary stop (interruption) command to the recording / reproducing head 24P. The read pause operation includes returning the head by one track (skip).
This is achieved by continuing until a read start command is issued.

When the encoded data is decoded at the encoded transmission rate Rb and the encoded data is consumed from the buffer 28 and the buffer fullness is reduced to some extent (for example, 25%), a signal notifying the buffer fullness of 25% is sent from the buffer 28 to the data read control unit. 2
9 When a signal indicating the sufficiency is supplied, the data reading control 29 sends a signal to the recording / reproducing head 24P.
Issue a read start command. The start of reading can be achieved by canceling the operation of returning (skipping) the head by one track. Even when the reproduction data selection unit 27 selects the coded signal recorded immediately before, the reproduction operation of the recording / reproduction head 24P is the same as the other reproduction operation except that the recording area for reproducing the signal is different.

Next, the recording / reproducing timing in the case of the two-head system of one embodiment of the coded signal recording / reproducing apparatus of the present invention will be described with reference to FIG. Here, the description will be made on the assumption that the encoded data is variable rate encoding. FIG. 4A shows a state in which the input data is input to the data buffer 3 at the maximum rate (first transmission rate) Ra of the encoded data and is recorded at the rate Ra at the recording start time. After the buffer 3 is occupied almost to the maximum, the recording / reproducing is performed at the same rate Ra (the speed at which data enters and the speed at which data is recorded on the RAM disk is equal to Ra). As shown in 4 (a),
It becomes flat after the start of recording.

The heads are a recording head 4 and a reproducing head 7
And two heads, so that recording and reproduction can be performed simultaneously with recording. The reproduction is read out at the rate Ra, stored in the buffer 9, and starts decoding when the maximum is reached. Since the coding rate Rb is smaller than the transmission rate Ra,
The buffer 9 is attached to the upper limit as shown in FIG.
By continuing the operation of returning the head (skip), the reading is stopped above the maximum.

Next, the recording / reproducing timing in the case of the one-head system of one embodiment of the coded signal transmission / reproducing apparatus of the present invention will be described with reference to FIG. FIG.
(a) indicates that the input data is stored in the first buffer 23 at the transmission rate Ra.
Indicates that the recording is started at the recording start time at a rate Rc at least twice as fast as the rate Ra. Therefore, the data buffer is reduced accordingly. In the time until the reduced amount is satisfied again at the rate Ra, the head 24P
Is switched from recording to reproduction, and reproduction is performed. Basically, when recording at a rate Rc that is twice as fast as the rate Ra, the recording time and the reproduction time are distributed in half each.

FIG. 5 (b) shows a situation in which a recording signal is reproduced from the recording medium 26 by the reproducing head 24P in the reproducing section, and is input to the second buffer 28 at a third transmission rate Rc in a burst manner. Things. The buffer 28 decreases when each picture is decoded, and does not increase or decrease until the reproduction period (reproduction time). Such a burst-like input is performed for each picture display period (1 / 29.97 seconds (sec))
FIG. 5 (c) shows the result of averaging.

[0027]

According to the present invention, irrespective of the head system, in any case, the coded signals are all recorded on the recording medium, while there is no need to wait until the coded signals are completely recorded on the recording medium. , You can play back at the same time you start recording,
It is also possible to reproduce another coded data that has already been recorded while recording the entire coded signal on the recording medium.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of an encoded signal recording / reproducing apparatus (two-head system) of the present invention.

FIG. 2 is a block diagram of an embodiment of an encoded signal recording / reproducing apparatus (one-head system) of the present invention.

FIG. 3 is a block diagram of an example of the related art.

FIG. 4 is a diagram showing the concept of recording / reproducing timing in the case of an embodiment of a coded signal transmission recording / reproducing apparatus (two-head system) of the present invention.

FIG. 5 is a diagram showing the concept of recording / reproducing timing in the case of an embodiment of a coded signal transmission recording / reproducing apparatus (one-head system) of the present invention.

[Explanation of symbols]

1A, 21A, 31A Audio encoding unit 1V, 21V, 31V Image encoding unit 2, 22, 32 Multiplexer 3, 9, 23, 28, 33, 36 Buffer (buffer memory) 4 Recording head 5, 25 Data Write control unit 6, 26, 35 Recording medium (RAM disk) 7 Reproduction head 8, 27 Reproduction data selection unit 10, 29 Data read control unit 11, 30, 37 Demultiplexing unit 12A, 31A, 38A Audio decoding unit 12V , 31V, 38V Image decoding unit 24R, 24P, 34R, 34P Recording / reproducing head (recording / reproducing head)

Claims (5)

[Claims] An encoded signal recording / reproducing apparatus for recording / reproducing an encoded signal on / from a recording medium by a recording head and a reproducing head, wherein a first buffering the encoded signal by a predetermined amount.
A recording head for recording the output of the first buffer on the recording medium at a predetermined transmission rate; an encoded signal recorded immediately before by the recording head;
Or a reproduction data selection unit for selecting which one of the other encoded signals already recorded is to be reproduced, and a recording area recorded immediately before the recording medium, or another encoded signal recording area already recorded A second buffer for reading out and buffering the read signal in a burst at the predetermined transmission rate by the read head and reproducing the encoded signal for a reproduction time length; And a data reading control unit for suspending reading from the recording medium in accordance with the buffer occupancy of the coded signal recorded in the buffer. 2. An encoded signal recording / reproducing apparatus for recording / reproducing an encoded signal on a recording medium by a recording / reproducing head, comprising: a first buffer for buffering the encoded signal by a predetermined amount at a predetermined transmission rate. Recording the output of the first buffer on the recording medium at a transmission rate higher than the predetermined transmission rate;
A recording / reproducing head for reproducing a recording signal from a recording area recorded immediately before on the recording medium, or another encoded signal recording area already recorded on the recording medium; and A reproduction data selection unit for selecting whether to reproduce the coded signal recorded immediately before or another coded signal already recorded; and, during the time when the data is buffered in the first buffer,
A second buffer for reading and buffering in bursts at a transmission rate higher than the predetermined transmission rate by the recording / reproducing head, and reproducing an encoded signal with a reproduction time length; A coded signal recording / reproducing apparatus, comprising: a data read control unit for temporarily stopping reading from the recording medium according to a buffer occupancy of the coded signal. 3. The coded signal recording / reproducing apparatus according to claim 1, wherein the recording medium is a readable / writable disk. 4. An encoded signal recording / reproducing method for recording / reproducing an encoded signal on / from a recording medium by a recording head and a reproducing head, wherein the encoded signal buffered by a first buffer by a predetermined amount is recorded. The recording head records at a predetermined transmission rate on a medium, and at the same time, the coded signal recorded immediately before or another coded signal that has already been recorded is selected by the reproduction data selection unit, and the reproduction head is selected. , The data is read out in a burst at the first transmission rate and recorded in the second buffer, the reading is temporarily stopped in accordance with the buffer occupancy of the recorded coded signal, and the coded signal is reproduced in the second time by the reproduction time length. A coded signal recording / reproducing method characterized by reproducing from a buffer. 5. A coded signal recording / reproducing method for recording / reproducing a coded signal on a recording medium by a recording / reproducing head, wherein the coded signal buffered by a first buffer by a predetermined amount at a predetermined transmission rate. Recorded on the recording medium by a recording / playback head at a transmission rate higher than the predetermined transmission rate, and a coded signal encoded at a transmission rate higher than the predetermined transmission rate recorded immediately before, or already recorded When another coded signal is selected by the reproduction data selection unit and the recording / reproduction head reads the data in a burst at a transmission rate higher than the predetermined transmission rate while the data is buffered in the first buffer. The data is recorded in the second buffer, and its reading is temporarily stopped according to the buffer occupancy of the recorded encoded signal. Coded signal recording and reproducing method characterized by reproducing degree from the second buffer at playback time length.