KR100816559B1 - Cd data play method with high resume speed - Google Patents

Abstract

A method for reproducing CD data with high return speed is provided to prevent delay of reproducing process of the CD data by recording the read data on a buffer and consecutively recalling the data from the buffer. A method for reproducing CD data with high return speed comprises the steps: turning on a CD device after receiving a CD reproduce command(S10); successively receiving the data from the CD device and recording the data on a recording location while forwarding the recording location on a buffer by a frame unit(S20); reading the data of a reproducing location by forwarding the reproducing location according to the data reproducing speed(S30); converting the read data into an audio signal and outputting it(S40); memorizing the recording and reproducing location after receiving a stop command, and turning off the CD device(S50); and turning on the CD device, recalling the recording and reproducing location which are stored before turn-off of the CD device, and performing the reading process again(S60).

Description

CD data playback method with high playback speed {CD data play method with high resume speed}

1 is a system block diagram for implementing a CD data playback method having a fast playback return speed upon returning to a CD playback mode according to an embodiment of the present invention;

2 is a view showing a data flow in the main control chip of the present invention;

3 is a view for explaining the concept of the buffer of the present invention,

4 is a flowchart showing a method of reproducing a CD data having a fast reproducing return speed when returning to a CD reproducing mode according to an embodiment of the present invention;

5 is a view showing an initial state before CD data is input to a buffer;

6 is a diagram illustrating a process of inputting CD data one by one in units of frames to a buffer;

7 is a view illustrating a state where CD data is completely filled in a buffer;

8 is a diagram illustrating a process of filling data from the beginning of the buffer again after CD data is filled in the buffer;

9 is a diagram illustrating a process of blocking data recording until the playback position is at an intermediate point when the recording position reaches the end of the buffer;

10 is a diagram showing a point in time at which the data recording is activated again when the playback position reaches the midpoint of the buffer;

11 is a view showing a situation in which reproduction and recording continue in a buffer;

12 is a diagram illustrating a situation in which data recording is blocked because the amount of data to be reproduced in the buffer exceeds half of the total buffer size;

FIG. 13 is a view showing a situation in which data recording is resumed since the reproduction position in the buffer is advanced so that the amount of data to be reproduced exceeds half of the total buffer size;

14 is a flowchart illustrating an operation process of a forty-stage operation of externally outputting an audio signal;

15 is a flowchart illustrating the operation of the fifty-stage operation of stopping CD playback in more detail.

FIG. 16 is a diagram showing a situation in which playback starts immediately from the playback position of the buffer when the CD playback mode is returned again, and CD data is read from the next data at the recording position.

The present invention relates to a method of reproducing a CD data having a fast reproducing speed upon returning to a CD reproducing mode. In particular, the present invention relates to a method of reproducing a CD data by reading data from a CD device, first writing the data to a buffer, and then sequentially retrieving and reproducing data from the buffer. The present invention relates to a CD data reproducing method which can prevent the CD data reproduction from being delayed due to the on / off of the CD device upon returning to the CD reproducing mode.

Conventional car audio or home audio for CD playback requires the following process to switch to another mode (eg FM radio broadcast) during CD playback.

(1) Save the current state of the CD (information such as playing a few minutes and a few seconds of the first track)

(2) Turn off the power of the CD device.

(3) Switch to another medium playback mode.

In order to return to the CD play mode from the other mode is as follows.

(4) Save the current state.

(5) End the current function.

(6) Turn on the power of the CD device.

(7) Recall the state of the stored CD and play the last played song again.

In the above process, after turning off the CD device and turning it on again, there is a difference for each CD device, but it requires 3 to 4 seconds of operation time before it is sufficiently activated to read CD data. No matter how good the mechanical behavior of the CD device is, it requires at least two seconds of waiting time.

In particular, since data files are compressed and stored in a data CD, it takes more time to play.

As described above, the conventional composite media playback apparatus including the CD playback function finds the last played position when the CD playback mode is switched to another media playback mode and returns to the CD playback mode. Due to the time required for resumption, the user was inconvenient to wait for the CD to be played as much as the required time.

Accordingly, the present invention has been made to solve the above-mentioned disadvantages and problems of the prior art, and reads data from a CD device, writes it first to a buffer, and then sequentially extracts and reproduces the data from the buffer to the CD playback mode. An object of the present invention is to provide a CD data reproducing method which can prevent the CD data reproduction from being delayed due to the on / off of the CD device upon reversion.

According to an aspect of the present invention, there is provided a CD data reproducing method comprising: a tenth step of turning on a CD device upon receiving a CD reproducing command through an external input; A twentieth step of sequentially receiving data from the CD device and recording the data at the recording position while advancing the recording position on the buffer in frame units; A thirtieth step of reading data of the reproduction position while advancing the reproduction position on the buffer at a reproduction speed; A 40th step of converting data read from the buffer into an audio signal and outputting the audio signal to the outside; A fifty step of storing a recording position and a playback position in a memory unit and turning off the CD device when receiving a CD playback stop command through an external input; And 60, when the CD play command is input through an external input, issue a CD device ON command, recall the recording position and the play position stored before the CD device OFF from the memory unit, and proceed to the thirtieth step. It is composed.

In addition, the twentieth step in the CD data reproducing method according to the present invention for achieving the above object comprises a step of receiving data from the CD device at a speed of 2 times or more.

Further, in the CD data reproducing method according to the present invention for achieving the above object, the buffer is composed of a circular ring buffer, and in step 20, when the recording position reaches the last frame of the buffer, the recording position is converted into the first frame of the buffer. And moving the data to record the data, and the thirtieth step includes moving the play position to the first frame of the buffer and reading data when the play position reaches the last frame of the buffer.

Further, in the CD data reproducing method according to the present invention for achieving the above object, in the twelfth step, when the recording position reaches the last frame of the buffer, the size of the data to be reproduced in advance is a predetermined ratio of a predetermined ratio of the total buffer size. And stopping the recording until it becomes smaller.

Further, in the CD data reproducing method according to the present invention for achieving the above object, in the twentieth step, when the size of data to be reproduced in the future exceeds the ratio threshold of the total buffer size, recording is stopped, and the size of data to be reproduced in the future is increased. Resuming recording if it does not exceed the ratio threshold of the total buffer size.

Further, in the CD data reproducing method according to the present invention for achieving the above object, the forty-fourth step may include converting an analog audio signal into an external audio signal and outputting the external data when the data read from the buffer is audio data; A fourth step of decoding the data if the read data is compressed data; A forty-third step of verifying a reproduction time zone of the data decoded in the forty-second step through the data before and after the above read data on the buffer; And a 44 th step of converting the decoded data into an analog audio signal and outputting the external signal.

Further, in the CD data reproducing method according to the present invention for achieving the above object, the fifty-seventh step includes: storing a recording position and a reproduction position in a memory unit when another medium reproduction command is received; A 52nd step of turning off the CD device; And a fifty-seventh step of switching to another medium playback mode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a system block diagram for implementing a CD data playback method having a fast playback return speed upon returning to a CD playback mode according to an embodiment of the present invention.

As shown, the CD stores audio data or compressed data, and the CD DSP controls the hardware operation of the CD and delivers basic data necessary for playback to the main control chip (Decoder). The main control chip (Play & Control Chip) analyzes data such as audio or data (MP3) made from CD through CD DSP and plays back correctly. In the present invention, a special device is added so that a playback delay is not made in the process of turning the CD off and then on again.

2 is a view showing a data flow in the main control chip of the present invention.

As shown, a buffer, preferably a middle buffer, is added so that both the data CD and the audio CD are configured to pass data through the buffer. Here, the buffer acts like a container for a brief flow of running water.

3 is a view for explaining the concept of the buffer used in the present invention.

As shown in the figure, the buffer stores data in a time period of 2 minutes and 10 seconds to data in a time period of 3 minutes and 10 seconds. The replay action is a sound that moves over time, so it's like water flowing down, and the buffer keeps it for a while.

The role of the buffer is that when switching from CD play mode to other media play mode, since there is no data to be supplied to the buffer, there is no sound to play, so it saves all the data in the stopped time zone.

Then, when the player enters the CD play mode again, the sound is played using the data in the buffer, and while the data in the buffer is reproduced as an audio signal, the last data stored in the buffer is read from the CD and stored in the buffer. . Through this process, the user can immediately hear the data stored in the buffer, so that the user cannot feel the waiting time due to the CD ON / OFF operation.

4 is a flowchart illustrating a method of reproducing a CD data having a fast reproducing speed when returning to a CD reproducing mode according to an embodiment of the present invention.

As shown in the drawing, first, when receiving a CD play command through an external input, the CD device is turned on (S10).

Subsequently, data is sequentially input from the CD device and data is recorded at the recording position while advancing the recording point on the buffer in frame units (S20).

Then, data of the reproduction position is read while advancing the reproduction position (output point) on the buffer to the reproduction speed (S30).

In this case, when data is input from the CD device in step 20 (S20), it is preferable to receive data at a reproduction speed of 2 times or more, which means that the recording position advances at a faster speed than the reproduction position so that the recording position is behind the reproduction position. This is to prevent data from being interrupted by not losing it.

In addition, the buffer may operate as a circular ring buffer. In the twentieth step (S20), when the recording position reaches the last frame of the buffer, the data is recorded by moving the recording position to the first frame of the buffer, and in the thirtieth step (S30). ) Reads data by moving the playback position to the first frame of the buffer when the playback position reaches the last frame of the buffer. As described above, an operation of continuously recording and reproducing data using a buffer having a limited size by operating the buffer as a circular ring buffer will be described in more detail with reference to FIGS. 5 to 8.

5 is a diagram illustrating an initial state before CD data is input to a buffer.

As shown, the buffer consists of frames, which are data units of CDs, and the continuous storage space of these frames is linearly contiguous. An input point is a value indicating a recording position at which data is input, and an output point is a value indicating a reproduction position at which data to be reproduced is recorded. Both the input point and the output point increase by one frame unit, and the data is inputted to the input point because the CD data is input at the double speed or more at the initial state.

6 is a diagram illustrating a process of inputting CD data one by one in units of frames to a buffer.

As shown, the input point is increasing, filling the data and the output point is pulling the data.

7 is a diagram illustrating a state in which CD data is filled in a buffer.

As shown, it can be seen that over time, the input point has reached the last position of the buffer and there are many time gaps with the output point compared to the initial state. In this case, the buffer can be used as a circular ring buffer, and the size of the limited buffer can be overcome by deleting the oldest obsolete data on the buffer and writing new data thereon.

8 is a diagram illustrating a process of filling data from the beginning of the buffer again after CD data is filled in the buffer.

As shown, when the input point reaches the last position of the buffer, it can be seen that data has been recorded by moving back to the first position of the buffer. As the output point continues to play data, it moves forward toward the end of the buffer. When the end point of the buffer is reached, the output point moves to the beginning of the buffer to read and play data.

As described above with reference to FIGS. 5 to 8, the buffer may be used as a circular ring buffer to overcome the limited size of the buffer. However, the output point is slower than the input point, so the data may overtake the output point.

To prevent this, in the twentieth step S20, when the recording position reaches the last frame of the buffer and there is no more empty buffer, recording is stopped until the size of data to be played back becomes smaller than the ratio threshold of the total buffer size. Done. In this case, the ratio threshold may be set to various values according to the characteristics and purposes of the entire system. For example, if the ratio threshold is set to 1/2, the data point is stopped by keeping the input point as it is until the output point is half the full buffer size and stopping reading data from the CD device.

In addition, the twentieth step S20 stops recording when the size of data to be reproduced in the future exceeds the ratio threshold of the total buffer size and resumes recording when the size of data to be reproduced in the future does not exceed the ratio threshold of the total buffer size.

9 is a diagram illustrating a process of blocking data recording until the playback position reaches the middle point when the recording position reaches the end of the buffer.

As shown, the input point has reached the last position of the buffer, but the output point has not progressed more than half of the rate threshold set at the initial position, and when the buffer is viewed from the point of view of the circular ring buffer, the input point is the output point. The input point stops and data recording is interrupted until the output point is half way through the buffer.

Fig. 10 is a diagram showing a point in time when the reproduction position reaches the intermediate point of the buffer and data recording is activated again.

As shown, the input point is still stopped, but since the operation of reading data and playing the audio signal in the CD play mode is ongoing, the output point continues to move forward in the buffer to reach the half point of the buffer. At this point, the size of the data to be played back (input point-output point) becomes larger than half of the total buffer size, so that data is read from the CD and written to the buffer again. At this time, since the input point is at the last position of the buffer, the data is recorded by moving the input point to the first position of the buffer, which is the next position on the circular ring buffer.

11 is a diagram showing a situation where reproduction and recording continue in the buffer.

As shown in the drawing, data on the buffer is read and reproduced while the output point is continuously moved, and the input point is in a state where data is read from the CD and recorded on the buffer.

12 is a diagram illustrating a situation in which data recording is blocked because the amount of data to be reproduced in the buffer exceeds half of the total buffer size.

As shown, in general, since the moving speed of the input point is faster than the moving speed of the output point, the size of the data to be played back (input point-output point) becomes larger than 1/2 of the total buffer size, so the movement of the input point is restarted. It is stopped.

Fig. 13 is a view showing a situation where data recording is resumed since the reproduction position in the buffer is advanced so that the amount of data to be reproduced exceeds half of the total buffer size.

As shown in the drawing, the output point continues to move while the input point is stopped, and the size of data to be reproduced in the future becomes smaller than half of the total buffer, and thus the data recording from the CD is resumed.

In this way, the data is recorded on the buffer and the recorded data is read, and the data read from the buffer is converted into an audio signal and output to the outside (S40).

14 is a flowchart illustrating the operation of the forty-stage operation of externally outputting an audio signal in more detail.

As shown in the drawing, when the data read from the buffer is audio data, the signal is converted to an analog audio signal and externally output (S41). Audio data is pure 16-bit audio data that can be output directly, so take the data directly from the output point.

However, if the read data is compressed data, after decoding the data (S42), the reproduction time zone of the decoded data is verified in step 42 through the data before and after the read data on the buffer (S43). In other words, compressed data such as WMA should be decoded in the last played time zone (eg msec) when resuming in CD play mode, and then confirmed whether the data is in that time zone. See historical data.

Thereafter, the decoded data is converted into an analog audio signal and externally output (S44).

Next, when the CD playback stop command is received through the external input, the recording position and the playback position are stored in the memory unit and the CD device is turned off. If there is no input of the CD playback stop command, the process proceeds to step 20 (S20). S50).

15 is a flowchart illustrating the operation of the fifty-stage operation of stopping CD playback in more detail.

As shown in the figure, if there is no special external input, the process proceeds to step S20 to continue the process of recording and reproducing the data. If a CD play stop command such as another medium play mode execution command is input, After storing the recording position and the reproduction position in the memory unit (S51), the CD device is turned off (S52), and another medium reproduction mode is performed (S53).

When the CD play command is received through the external input, the CD device ON command is issued, and the recording position and the play position are read back from the memory unit, and the process proceeds to step 30 (S60). That is, since playback is performed by reading data of the loaded playback position from the buffer, switching to the CD playback mode is performed immediately without delay.

FIG. 16 is a diagram showing a situation in which playback starts immediately from the playback position of the buffer when the CD playback mode is returned again, and CD data is read from the next data at the recording position.

As shown, playback is performed by reading the data of the buffer corresponding to the output point stored in the memory unit, and it takes time for the CD device to be turned on and activated as background control during data playback. Once fully activated, CD data is read and data recording is resumed on the buffer from the next value of the previously stored input point.

Although the present invention has been described in more detail with reference to examples, the present invention is not necessarily limited to these examples, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, when a CD is inserted unless the CD is removed from the CD device and initialized, the CD playback system returns to the CD playback mode when the CD is in the other media playback mode. Otherwise, there is an effect that the data is reproduced immediately without the waiting time caused by the hardware limitation of the CD device.

Claims (7)

A tenth step of turning on the CD device upon receiving a CD play command; A twentieth step of sequentially receiving data from the CD device and recording the data at the recording position while advancing the recording position on the buffer in frame units; A thirtieth step of reading data of the playback position while advancing a playback position on the buffer to a playback speed; A 40 step of converting the data read from the buffer into an audio signal and outputting the external signal; A fifty step of storing the recording position and the reproduction position in a memory unit when the CD reproduction stop command is received and turning off the CD device; And A 60th step of giving a CD device ON command upon receiving a CD playback command and reloading the recording position and the playback position stored before the CD device OFF from the memory unit and proceeding to the thirtieth step; CD data playback method comprising a. The method of claim 1, The twentieth step includes receiving data from the CD device at a speed of 2 times or more. The method of claim 2, wherein the buffer is a circular ring buffer, The twentieth step further comprises the step of recording data by moving the recording position to the first frame of the buffer when the recording position reaches the last frame of the buffer, And wherein the thirty step comprises reading data by moving the playback position to the first frame of the buffer when the playback position reaches the last frame of the buffer. The method of claim 3, wherein The 20th step may further include stopping the recording until the recording position reaches the last frame of the buffer until the size of data to be played back becomes smaller than a predetermined specific ratio threshold of the total buffer size. CD data playback method. The method of claim 4, wherein The twentieth step stops recording when the size of data to be reproduced in the future exceeds the ratio threshold for the total buffer size, and resumes recording when the size of data to be reproduced in the future does not exceed the ratio threshold of the total buffer size. CD data playing method further comprises. The method of claim 5, wherein The forty-seventh step may include: converting an analog audio signal into an external audio signal and outputting the external data when the data read from the buffer is audio data; A 42nd step of decoding the data when the read data is compressed data; Verifying a reproduction time zone of the data decoded in the forty-second step through the data before and after the read data on the buffer; And A 44 th step of converting the decoded data into an analog audio signal and outputting the external signal; CD data playback method comprising a. The method of claim 6, In a fifty-fifth step, storing the recording position and the reproduction position in a memory unit when a command for reproducing another medium is received; A 52nd step of turning off the CD device; And A 53rd step of switching to another medium playback mode; CD data playback method comprising a.

Images