JP2001143388A - Reproduction speed adjusting method of video recording and reproducing device, and video recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproducing speed adjusting method of a video recording and reproducing device which enables reproduction to be performed at the same reproduction speed as a recording speed without adjusting the reproduction speed by a user. SOLUTION: In the recording mode, the recording speed is recorded on a recording medium together with image data and, in the reproducing mode, the recording speed is read out from the recording medium together with the image data to adjust the reproduction speed to the same speed as the read recording speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproduction speed adjusting method for a video recording / reproducing apparatus and a video recording / reproducing apparatus.

[0002]

2. Description of the Related Art A digital VTR having a function of continuously or intermittently recording image data picked up by a surveillance camera on a video tape and a function of reproducing the image data recorded on the video tape has already been provided. Is being developed.

When image data is recorded intermittently,
A predetermined number of field cycles (hereinafter referred to as an image capture cycle)
Then, the image data is captured. For example, when image data is captured at a rate of one field in two fields, 30 fields of image data are captured per second, and when image data is captured at a rate of one field in four fields, 15 fields per second. When image data of a field is captured and image data is captured at a ratio of one field to eight fields, image data of 7.5 fields is captured per second. The number of fields captured per second is referred to as a recording speed.

Since the recording time changes in accordance with the recording speed, such as the higher the recording speed (the shorter the image capture period), the shorter the recording time, the recording speed is set by the user in the form of a recording time mode. It is supposed to be. For this reason, the recording speed is not always constant. At the time of reproduction, in order to perform reproduction at a reproduction speed corresponding to the recording speed, the user writes down the relationship between the recording time and the recording speed, and sets the reproduction speed while watching the recording time during reproduction. Needed. Alternatively, it is necessary to display the playback speed on-screen (OSD) during recording, record the display and the image together, and confirm the playback speed displayed on the screen during playback, and set the playback speed. there were.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a reproduction speed adjusting method and a video recording / reproducing method for a video recording / reproducing apparatus which enables reproduction at the same reproducing speed as a recording speed without a user adjusting the reproducing speed. It is intended to provide a device.

[0006]

According to the present invention, there is provided a method for adjusting a reproducing speed in a video recording / reproducing apparatus, wherein a recording speed is recorded on a recording medium together with image data during recording, and the recording speed is recorded together with the image data from the recording medium upon reproducing. And the reproduction speed is adjusted to the same speed as the read recording speed.

The reproduction speed is adjusted by temporarily storing image data read from a recording medium in a memory at the time of reproduction, and setting a read interval between fields or frames according to the recording speed read from the recording medium. , By reading image data from the memory for each field or frame.

A first video recording / reproducing apparatus according to the present invention is a means for recording a recording speed together with image data on a recording medium at the time of recording, and reading the recording speed together with image data from the recording medium at the time of reproduction, And a reproducing speed adjusting means for adjusting the recording speed to the same as the recording speed at which the data was read.

The reproduction speed adjusting means includes, for example, means for temporarily storing image data read from a recording medium in a memory, and reading intervals between fields or frames according to the recording speed read from the recording medium. In this case, a device is used which has a means for adjusting the reproduction speed to the same as the recording speed by reading the image data from the memory for each field or each frame.

A second video recording / reproducing apparatus according to the present invention provides a video recording / reproducing apparatus in which alarm information indicating an important scene is recorded as additional information together with image data on a recording medium at the time of recording. ,
Means for recording the recording speed on the recording medium as additional information,
At the time of reproduction, the image data and the additional information are read from the recording medium, and for the image data in which the additional information includes the alarm information, the reproduction speed of the image data is set to
A reproduction speed adjusting means for adjusting the recording speed in the additional information to the same speed as the recording speed in the additional information and adjusting the reproduction speed of the image data to the reproduction speed set by the user for the image data in which the additional information does not include the alarm information; It is characterized by having.

The reproduction speed adjusting means includes, for example, means for temporarily storing image data read from a recording medium in a memory, and when additional information read from the recording medium includes alarm information, At a read interval between fields or frames corresponding to the recording speed included in the information, image data is read from the memory for each field or frame, so that the reproduction speed is adjusted to the same as the recording speed. Means, and if the additional information read from the recording medium does not include the alarm information, the image data is stored in one field from the memory at intervals of reading between fields or frames according to the reproduction speed set by the user. Alternatively, by reading out each frame, the playback speed is the same as the playback speed set by the user. We shall have a means for adjusting the speed is used.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a digital VTR that records and reproduces a video image captured by a surveillance camera will be described below with reference to the drawings.

FIG. 1 shows the configuration of a digital VTR. In FIG. 1, the audio signal processing circuit is omitted.

The digital VTR includes a video signal processing circuit 1,
A servo system (drum servo system and capstan servo system) 2, a system control circuit 3, a mechanical system 4, an operation panel 5, and the like are provided.

The video signal processing circuit 1 includes a decoder (A / D
Converter) 11, first FPGA (field programmable gate array) 12, field memory 13, JP
EG type image compression / expansion circuit 14, memory 16, formatter 18, signal recording / reproducing unit 19, second FPGA 2
0, an encoder (D / A converter) 21 and a microcomputer (hereinafter referred to as a microcomputer) 22.

The signal recording / reproducing unit 19 includes a recording amplifier, a reproducing amplifier, and a video head. The image compression / decompression circuit 14, the memory 16, and the formatter 18 are controlled by the second FPGA 20. First FPGA
The 12 and the second FPGA 20 are controlled by the microcomputer 22.

The operation at the time of recording will be described. Here, the case where the recording unit is one field unit will be described, but the present invention can also be applied when the recording unit is one frame unit. At the time of recording, an analog video signal sent from a surveillance camera (video camera) is converted by the decoder 11 into digital image data. The image data obtained by the decoder 11 is sent to the first FPGA 12.

The first FPGA 12 stores the input image data in the field memory 13 at an image capture cycle (recording speed) according to the recording time mode set by the user. For example, at a ratio of one field to four fields (when the recording speed is 15 [field / second]),
Image data is stored in the field memory 13.
The recording time mode is input by the operation panel 5 and set in the microcomputer 22 via the system control circuit 3. The image data stored in the field memory 13 is sent to an image compression / expansion circuit 14, where the image data is compressed and converted into encoded data.

The second FPGA 20 adds additional information such as a recording speed and a recording time to the encoded data obtained by the image compression / expansion circuit 14. Then, the encoded data to which the additional information has been added is written to the memory 16.

Every time the amount of data written in the memory 16 becomes an amount corresponding to one block unit (a predetermined amount of data for a plurality of fields), data is read from the memory 16 and sent to the formatter 18, The formatter 18 converts the data into data having a data structure that can be recorded on a video tape.

The data obtained by the formatter 18 is recorded on a video tape (recording medium) 23 via a recording amplifier and a video head in a signal recording / reproducing unit 19.

The operation at the time of reproduction will be described. At the time of reproduction, data read from the video tape 23 by the video head in the signal recording / reproducing unit 19 is temporarily stored in the memory 16 via the reproducing amplifier and formatter 18 in the signal recording / reproducing unit 19. Second FPGA
20 acquires additional information from the data stored in the memory 16. The additional information obtained by the second FPGA 20 is sent to the microcomputer 22.

The second FPGA 20 reads out data (encoded data) other than the additional information from the data stored in the memory 16 on a field-by-field basis. At this time, the second FPGA 19 sets the read interval between fields to
The control is performed according to the reproduction speed determined by the microcomputer 22 as described later.

The encoded data read from the memory 16 is sent to the image compression / decompression circuit 14 and decompressed. Digital image data obtained by the image compression / expansion circuit 14 is stored in the field memory 13. The image data for one field stored in the field memory 13 is repeatedly read by the first FPGA 12 and sent to the encoder 21. The encoder 21 converts the sent image data into an analog video signal, and then sends it to a monitor (not shown).

FIG. 2 is a time chart for explaining a method of changing the reproduction speed.

Here, it is assumed that, at the time of recording, as shown in FIG. 2A, image data is taken into the field memory 13 at intervals of To seconds. Here, for convenience of explanation, at the time of recording, the recording speed is 1 [field / sec].
It is assumed that image data is fetched into the field memory 13 at a rate of one field per second (a rate of one field per 60 fields).

FIG. 2B shows a case where the reproduction speed is set to the same speed as the recording speed (1 [field / sec]). In this case, the image data is
When reading is performed for each field, the reading interval T between fields is set to 1 second (To). Encoded data for one field read from the memory 16 at one-second intervals is decompressed by the image compression / decompression circuit 14 and then stored in the field memory 13. First FPGA 12
Reads out the image data stored in the field memory 13 repeatedly and sends it to the encoder 21. Therefore, the same image is repeatedly displayed every second. The cycle T at which the video is switched is the same as the image capture cycle To during recording.

FIG. 2C shows a case where the reproduction speed is set to twice the recording speed (2 [field / sec]). In this case, when the image data is read from the memory 16 for each field, the read interval T between the fields is set to 0.5 seconds (To / 2). Encoded data for one field read from the memory 16 at 0.5 second intervals is expanded in the image compression / expansion circuit 14 and then stored in the field memory 13. First FPG
A12 repeatedly reads out the image data stored in the field memory 13 and sends it to the encoder 21. Therefore, the same image is repeatedly displayed every 0.5 seconds. The cycle T at which the video is switched is の of the image capture cycle To during recording.

FIG. 2D shows that the reproduction speed is 1 / the recording speed.
The figure shows a case where the setting is twice (0.5 [field / sec]). In this case, when image data is read from the memory 16 for each field, the read interval T between fields is set to 2.0 seconds (2To). Encoded data for one field read from the memory 16 at 2.0-second intervals is expanded in the image compression / expansion circuit 14 and then stored in the field memory 13. First FP
The GA 12 repeatedly reads out the image data stored in the field memory 13 and sends it to the encoder 21. Therefore, the same image is repeatedly displayed every 2.0 seconds. The cycle T at which the video is switched is twice the image capture cycle To during recording.

FIG. 3 shows a processing procedure for determining the reproduction speed.

In this digital VTR, there are a manual setting mode and an automatic setting mode as a reproduction speed setting mode.

The manual setting mode is a mode in which reproduction is performed at a reproduction speed set by the user. The automatic setting mode is a mode in which reproduction is always performed at the same reproduction speed as the recording speed.

At the time of reproduction, a reproduction speed determination processing procedure for determining a reproduction speed (reading interval between fields) for one field of encoded data stored in the memory 16 will be described.

First, it is determined whether or not the reproduction speed setting mode is the automatic setting mode (step 1).

If the reproduction speed setting mode is the automatic setting mode, the recording speed in the additional information corresponding to the reproduction data is determined as the reproduction speed (step 2).

If the reproduction speed setting mode is not the automatic setting mode, it is determined that the reproduction speed setting mode is the manual setting mode, and the reproduction speed set by the user is determined as the reproduction speed (step 3).

When the playback speed is determined in step 2 or 3, playback is performed at the determined playback speed (step 4). That is, data to be reproduced is read from the memory 16 at a read interval between fields corresponding to the determined reproduction speed.

For example, when the recording speed is 30 [field /
Second], the read interval between fields is 1
/ 30 seconds. When the recording speed is 15 [field / sec], the read interval between fields is 1/15.
Seconds. When the recording speed is 7.5 [fields / sec], the read interval between fields is 1 / 7.5 seconds.

It is to be noted that an automatic setting mode at the start of reproduction for performing reproduction at the same reproduction speed as the recording speed only at the start of reproduction may be added as the reproduction speed mode. If the automatic setting mode is set at the start of playback and the automatic setting mode is not set, playback is performed at the same playback speed as the recording speed only at the start of playback, and thereafter playback is performed at the playback speed set by the user. Done.

FIG. 4 shows another example of the reproduction speed determination processing procedure.

In this example, as the reproduction speed setting mode,
There are manual setting mode and automatic setting mode.

At the time of recording, it is assumed that alarm information indicating an important scene is input to the digital VTR by the alarm information generating means, and the alarm information is also recorded as additional information. As the alarm information generating unit, for example, a unit that detects a motion vector from a captured image and outputs alarm information when the motion vector is large, a human detection sensor installed in a monitoring area, or the like is used.

At the time of reproduction, a reproduction speed determination processing procedure for determining a reproduction speed (reading interval between fields) for one field of encoded data stored in the memory 16 will be described. First, it is determined whether or not alarm information is included in the additional information corresponding to the reproduction data (step 11).

If the additional information corresponding to the reproduction data does not include the alarm information, the reproduction speed set by the user is determined as the reproduction speed (step 12).

If the additional information corresponding to the reproduction data contains alarm information, it is determined whether the reproduction speed setting mode is the automatic setting mode (step 13).

If the reproduction speed setting mode is not the automatic setting mode, it is determined that the reproduction speed setting mode is the manual setting mode, and the reproduction speed set by the user is determined as the reproduction speed (step 12).

If the reproduction speed setting mode is the automatic setting mode, the recording speed in the additional information corresponding to the reproduction data is determined as the reproduction speed (step 14).

When the playback speed is determined in step 12 or 14, playback is performed at the determined playback speed (step 15). That is, data to be reproduced is read from the memory 16 at a read interval between fields corresponding to the determined reproduction speed.

[0049]

According to the present invention, reproduction can be performed at the same reproduction speed as the recording speed without adjusting the reproduction speed by the user.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a digital VTR.

FIG. 2 is a time chart for explaining a method of changing a reproduction speed.

FIG. 3 is a flowchart illustrating a playback speed determination processing procedure;

FIG. 4 is a flowchart showing another reproduction speed determination processing procedure.

[Explanation of symbols]

 Reference Signs List 1 video signal processing circuit 2 servo system 3 system control circuit 4 mechanism system 5 operation panel 11 decoder 12 first FPGA 13 field memory 14 image compression / decompression circuit 16 memory 18 formatter 19 signal recording / reproducing unit 20 second FPGA 21 encoder 22 Microcomputer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/937 H04N 5/93 C 5/93 Z G11B 27/00 A F term (Reference) 5C018 FA01 FA03 FB06 HA08 HA09 NA06 5C053 FA11 FA22 GA11 GB06 GB21 GB36 HA24 HA33 JA21 JA22 JA30 KA03 KA24 LA01 LA06 5D044 AB07 DE03 DE42 DE49 EF05 FG10 FG18 GK12 5D110 DA06 DA11 DB02 DC01 DC11 DE01

Claims (6)

[Claims] At the time of recording, a recording speed is recorded on a recording medium together with image data at the time of recording, and at the time of reproduction, the recording speed is read together with the image data from the recording medium, and the reproduction speed is adjusted to the same recording speed as the read recording speed. A playback speed adjustment method in a playback device. 2. At the time of reproduction, image data read from a recording medium is temporarily stored in a memory, and an image is read from the memory at intervals of reading between fields or frames according to the recording speed read from the recording medium. 2. The read speed is adjusted to the same speed as the recording speed by reading data one field or one frame at a time.
3. A reproduction speed adjusting method in the video recording / reproducing apparatus according to 1. 3. A means for recording a recording speed together with image data on a recording medium during recording, and reading a recording speed together with image data from a recording medium during reproduction and adjusting the reproducing speed to the same recording speed as the read recording speed. A video recording / reproducing apparatus comprising: 4. A reproducing speed adjusting means for temporarily storing image data read from a recording medium in a memory, and at a read interval between fields or between frames according to the recording speed read from the recording medium. 4. The video recording / reproducing apparatus according to claim 3, further comprising: means for reading out the image data from the memory for each field or frame to adjust the reproducing speed to the same as the recording speed. 5. A video recording / reproducing apparatus in which alarm information indicating an important scene together with image data is recorded as additional information on a recording medium at the time of recording. Means for recording image data and additional information from a recording medium during reproduction, and for image data for which alarm information is included in the additional information, the reproduction speed of the image data;
A reproduction speed adjusting means for adjusting the recording speed in the additional information to the same speed as the recording speed in the additional information and adjusting the reproduction speed of the image data to the reproduction speed set by the user for the image data in which the additional information does not include the alarm information; A video recording / reproducing device, comprising: 6. A reproducing speed adjusting means for temporarily storing image data read from a recording medium in a memory, and when the additional information read from the recording medium includes alarm information, the additional information Means for adjusting the reproduction speed to the same as the recording speed by reading image data from the memory for each field or frame at intervals of reading between fields or frames according to the recording speed included in the recording speed And if the additional information read from the recording medium does not include the alarm information, the image data is stored in one field or from the memory at intervals of reading between fields or frames according to the playback speed set by the user. By reading every frame, the playback speed is adjusted to the same as the playback speed set by the user. Means, video recording and reproducing apparatus according to claim 5, characterized in that it comprises a.