JP2009053297A - Music recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a music recording device for automatically deleting a music content when the music content having poor receiving quality is recorded. <P>SOLUTION: The music recording device with a function of extracting the music content from a received broadcasting wave and recording it in a recording medium comprises: a first means for generating a receiving quality determination data for determining the receiving quality of the received broadcasting wave; a second means for determining the level of the receiving quality of the music content, based on the receiving quality determination data which is generated by the first means, while the music content is being received; and a third means for removing the music content from the recording device, when it is determined that the receiving quality of the music piece content is poor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a music recording apparatus having a function of receiving broadcast waves such as radio broadcasts and television broadcasts and extracting and recording music contents from the received broadcast waves.

  2. Description of the Related Art Music recording / playback apparatuses that have a function of receiving radio broadcast or television broadcast, extracting and recording music content from received broadcast waves, and playing back recorded music data are known. In such a music recording / playback apparatus, as the amount of recorded content increases, the free space of the recording medium decreases, and it becomes necessary to organize the recorded content.

  By the way, in the music recording / reproducing apparatus as described above, there is a possibility that music content with poor reception quality is recorded. The music content with poor reception quality is low in value to be played back, so it is content that does not need to be recorded.

Further, in the music recording / playback apparatus as described above, the same music content may be recorded in duplicate. It is undesirable from the viewpoint of effective use of the capacity of the recording medium that the same music content is recorded in duplicate.
JP 2007-96761 A

  An object of the present invention is to provide a music recording apparatus that can automatically delete music content when music content with poor reception quality is recorded.

  It is another object of the present invention to provide a music recording apparatus that can automatically delete music content having a lower reception quality when the same music content is recorded in duplicate.

  The invention according to claim 1 is a music recording apparatus having a function of receiving broadcast waves, extracting music contents from the received broadcast waves, and recording them on a recording medium. First means for generating reception quality determination data for determination, when recording of music content is completed, the reception quality determination data generated by the first means while receiving the music content And a second means for determining whether the reception quality of the music content is high or low, and a third means for deleting the music content from the recording medium when it is determined that the reception quality of the music content is low. It is characterized by having.

  The invention described in claim 2 is a music recording apparatus having a function of receiving broadcast waves, extracting music contents from the received broadcast waves, and recording them on a recording medium. First means for generating reception quality determination data for determination; when recording of music content is completed, reception quality determination data generated by the first means while receiving the music content; or Second means for storing data obtained from the reception quality determination data as reception quality data of the music content, when the recording of the music content is completed, the music content is recorded on the recording medium in duplicate. A third means for determining whether or not the music content is recorded on the recording medium in duplicate. Based on the reception quality data of the music contents for the same music, the reception quality of these music contents is compared, and at least the reception quality of the music contents other than the music content with the highest reception quality among these music contents. Characterized in that it comprises a fourth means for deleting the music content having the lowest value from the recording medium.

  According to a third aspect of the present invention, in the music recording device according to the first or second aspect, the music recording device has an S meter output terminal for outputting a signal corresponding to the electric field strength of the received broadcast wave. And a first means for generating reception quality determination data based on an output of an S meter output terminal of the tuner IC.

  According to a fourth aspect of the present invention, in the music recording device according to the first or second aspect, the music recording device mutes the output sound when the electric field strength of the received broadcast wave is equal to or lower than a predetermined threshold value. And a tuner IC having a mute drive output terminal for outputting a signal indicating whether or not the output sound is muted, and the first means is based on the output of the mute drive output terminal of the tuner IC. It is characterized in that it generates reception quality judgment data.

  According to a fifth aspect of the present invention, in the music recording device according to any one of the first to second aspects, the music recording device causes the output sound to be muted when the electric field strength of the received broadcast wave is below a predetermined threshold value. A tuner IC having a function is provided, and the first means detects a silent section from the recorded audio data and records the time in the silent section as reception quality determination data when music content is recorded. It is generated.

  According to the present invention, when music content with poor reception quality is recorded, the music content can be automatically deleted.

  Further, according to the present invention, when the same music content is recorded in duplicate, the music content with the lower reception quality can be automatically deleted.

  Embodiments of the present invention will be described below with reference to the drawings.

[1] Configuration of music recording / playback device

  FIG. 1 shows the configuration of a music recording / playback apparatus.

The music recording / playback apparatus includes an antenna 1, an FM tuner unit 2, an A / D conversion unit 3, a DSP 4, a recording medium 5, a D / A conversion unit 6, speakers 7 _L and 7 _R , an A / D conversion unit 8, and a memory 9. And a CPU 10.

  The FM tuner unit 2 selects a broadcast wave of a predetermined frequency selected by the user from the FM broadcast wave input via the antenna 1, demodulates the selected broadcast wave, and outputs the analog audio signal L of the left channel and The analog audio signal R of the right channel is output. As the FM tuner unit 2, an FM tuner IC having an S meter output terminal 2a is used. From the S meter output terminal 2a, a voltage according to the electric field strength of the selected FM broadcast wave is output. The output voltage of the S meter output terminal 2a increases as the electric field strength of the selected FM broadcast wave increases.

  The A / D converter 3 converts the analog audio signal obtained by the FM tuner unit 2 into a digital audio signal. In order to extract music, the DSP 4 extracts a change in audio power and a feature quantity in the frequency domain from an input digital audio signal, and a function that encodes a digital audio signal corresponding to the music into MP3 compressed data. And a function of decoding MP3 compressed data read from the recording medium 5 into a digital audio signal.

The recording medium 5 records MP3 compressed data obtained by the encoding function of the DSP 4. The D / A converter 6 converts the digital audio signal obtained by the decoding function of the DSP 4 into an analog audio signal. The speakers 7 _L and 7 _R output the left channel analog audio signal L and the right channel analog audio signal R obtained by the D / A converter 6.

  The S meter output terminal 2 a of the FM tuner unit 2 is connected to the A / D conversion unit 8. The A / D converter 8 outputs an L-level signal Lo when the voltage corresponding to the electric field intensity output from the S meter output terminal 2a is less than a predetermined reference voltage Vo, and from the S meter output terminal 2a. When the voltage corresponding to the output electric field strength is equal to or higher than the predetermined reference voltage Vo, an H level signal Hi is output. Data output from the A / D converter 8 is referred to as reception quality determination data. The reception quality determination data output from the A / D converter 8 is sent to the CPU 10.

  CPU10 controls each part of a music recording / reproducing apparatus. The memory 9 operates as a work memory for the CPU 10. Note that data such as a program of the CPU 10 is stored in a ROM (not shown).

Hereinafter, the process in the case of recording a music content is demonstrated.
[2] Music recording process

In the music recording process, only the music part is extracted from the received audio signal and recorded. When one piece of music content is recorded, it is determined whether the reception quality of the music content is good or bad. If the reception quality is bad, the music content is deleted. If the reception quality is good, it is determined whether or not the same music content as the music content has already been recorded. When the same music content as the music content has already been recorded, the one having the lower reception quality is deleted from both music contents.
[2-1] Extraction method of music part

  The digital audio signal input from the A / D converter 3 is input to the DSP 4 and also sent to the memory 9 via the DSP 4 and the CPU 10. The DSP 4 extracts the amount of change in audio power and the feature quantity in the frequency domain from the digital audio signal input to the DSP 4. The CPU 10 causes the memory 9 to hold digital audio signals for a predetermined past time from a new one. This predetermined time is set to a time longer than T1 seconds described later.

  In the music recording process, only the music part is extracted from the received audio signal and recorded. A method for extracting the music portion will be described. First, the CPU 10 detects a timing at which the amount of change in audio power is equal to or greater than a predetermined threshold as a change point. As the audio power, for example, a value obtained by squaring the amplitude of the audio signal is used. The CPU 10 stores the detection time (absolute time) in the memory 9 every time the change point is detected. After the number of change point detection time information stored in the memory 9 reaches a predetermined number, the CPU 10 deletes the oldest data and then stores new data. This predetermined number is set to be larger than the number of change points that can be detected for one music piece.

  When the CPU 10 detects the change point, the CPU 10 detects whether the vicinity of the change point is a song or a conversation part (talk part) by a radio program host (disc jockey) based on the feature amount in the frequency domain of the audio signal near the change point. Determine if it exists. For example, a mel cepstrum (MFCC: Mel Frequency Cepstral Coefficients) is used as the feature quantity in the frequency domain. More specifically, the likelihood between the detected MFCC and reference data (MFCC) for a previously created piece of music is calculated, and if the likelihood is greater than a predetermined threshold, the vicinity of the change point is the piece of music. Is determined. Alternatively, an evaluation value is calculated by substituting the MFCC near the change point into a previously created evaluation function, and based on the obtained evaluation value, it is determined whether the change point vicinity is a piece of music or a conversation part. May be.

  When it is determined that the vicinity of the change point is a song for a longer time than the predetermined time (T1 second), it is determined that the music segment has started from the time point before T1 second, and the sound starts from the position before T1 second. Start recording the signal. Thereafter, when it is determined that the vicinity of the change point is not a music piece, the recording position of the audio signal is delayed by T1 seconds. Therefore, recording of the audio signal is stopped when T1 seconds have elapsed from that point. T1 is set to a value within the range of 30 to 120 seconds, for example.

[2-2] Method for determining reception quality of music content whose recording has been completed

  Whether the reception quality of the music content that has been recorded is good or bad is determined as follows. The CPU 10 causes the memory 9 to retain reception quality determination data for a predetermined past time from a new one. This predetermined time is set to a predetermined time sufficiently longer than the length of one music piece. Then, when the recording of the music content ends, the average unit time of the reception quality determination data obtained during reception of the music (the sum of the reception quality determination data values obtained during reception of the music content) Is divided by the number of samples of reception quality determination data obtained during reception of the music content), and if the calculated average value is equal to or greater than a predetermined threshold, it is determined that the reception quality of the music content is good If the calculated average value is less than the predetermined threshold, it is determined that the reception quality of the music content is poor.

[2-3] Method for determining whether or not the same music content as the recorded music content has already been recorded

  Whether or not the same music content as the music content that has been recorded has already been recorded is determined as follows. As described above, the CPU 10 retains in the memory 9 detection time information of a predetermined number of change points in the past from a new one. When the recording of the music content is completed, the positions of the respective change points (elapsed from the start time of the music content) based on the detection time information of all the change points detected based on the digital audio signal of the music content. Time) and the obtained position of each change point is stored in the storage medium 5 as change point position information of the music content.

  And it is discriminate | determined whether it is the same music as the said music content with respect to each other music content already recorded. This determination is performed using the change point information and change point position information for the music content, and the change point information and change point position information for the other music content. Basically, between the music content that has been recorded and the other music content, the corresponding ones in the adjacent change point intervals are compared, and the change point intervals between the two in all corresponding change point intervals. Are substantially equal, it is determined that both music contents are the same music, and otherwise, it is determined that both music contents are not the same music. However, even if the music is the same, the number of change points may differ due to the lack of the beginning of one music content. In this embodiment, a discriminating method is adopted that makes it possible to determine that the music is the same even when the music is the same but the number of change points is different.

[2-4] Music recording processing procedure

  FIG. 2 shows a music recording process procedure.

  The FM tuner 1 is activated (step S1). Then, the feature extraction process by the DSP 4 is started, and the storage of the digital audio signal in the memory 9 and the storage of the reception quality determination data in the memory 9 are started (step S2). When the digital audio signal for a predetermined time is stored in the memory 9 after the storage of the digital audio signal in the memory 9 is started, the oldest digital audio signal is thereafter stored. The latest digital audio signal is recorded in the memory 9 after being deleted. Similarly, when reception quality determination data for a predetermined time is stored in the memory 9 after the storage of the reception quality determination data in the memory 9 is started, thereafter, The old reception quality determination data is deleted, and the latest reception quality determination data is recorded in the memory 9.

  The DSP 4 calculates the amount of change in audio power and the feature amount in the frequency domain from the digital audio signal input to the DSP 4 and supplies the calculated amount to the CPU 10. As the audio power, for example, a value obtained by squaring the amplitude of the audio signal is used. For example, a mel cepstrum (MFCC: Mel Frequency Cepstral Coefficients) is used as the feature quantity in the frequency domain.

  CPU10 determines whether it is a change point based on the variation | change_quantity of audio | voice power (step S3). If it is not a change point, the process returns to step S3. If it is determined that it is a change point, that is, if the change amount of the audio power is larger than a predetermined threshold (YES in step S3), the detection time (absolute time) of the change point is stored in the memory 9 (step) S4). When the predetermined number of change point detection time information is stored in the memory 9, the oldest change point detection time information is deleted, and the latest change point detection time information is stored. Recorded in the memory 9. The same applies to the case where the change point detection time (absolute time) is stored in the memory 9 in steps S9 and S14 described later. Next, based on the characteristic amount (MFCC in this example) of the audio signal in the vicinity of the change point detected this time, it is determined whether or not the change point vicinity is a piece of music (step S5). If the change point vicinity is not a music, it returns to step S3.

  In step S5, when it is determined that the vicinity of the change point is a music piece, the time measurement by the first timer is started (step S6). Then, it is determined whether or not the time measured by the first timer (Timer1) has exceeded T1 seconds (step S7). If the time measured by the first timer (Timer1) is equal to or shorter than T1 seconds, it is determined whether or not it is a change point based on the amount of change in audio power (step S8). If it is not a change point, the process returns to step S7.

  When it is determined in step S8 that the point is a change point, the detection time (absolute time) of the change point is stored in the memory 9 (step S9). Next, based on the feature amount (MFCC in this example) in the frequency domain of the audio signal in the vicinity of the change point detected this time, it is determined whether or not the change point vicinity is a music piece (step S10). When it is determined that the vicinity of the change point is music, the process returns to step S7.

  If it is determined in step S10 that the change point vicinity is not a music piece, the process returns to step S6 to start timing by the first timer. In this case, the time measurement by the first timer is restarted.

  If it is determined in step S7 that the time measured by the first timer (Timer1) has exceeded T1 seconds, it is determined that the music has started from T1 seconds before, and the time T1 seconds before the current time is The start time Ts is stored (step S11), and the encoding of the audio signal and the saving to the recording medium 5 are started from the position T1 seconds before (step S12).

  Next, it is determined whether or not the point is a change point based on the change amount of the audio power (step S13). If it is not a change point, the process returns to step S13. When it is determined that it is a change point, that is, when the change amount of the audio power is larger than a predetermined threshold (YES in step S13), the detection time (absolute time) of the change point is stored in the memory 3 (step) S14). Next, based on the feature amount (MFCC in this example) of the audio signal in the vicinity of the change point detected this time, it is determined whether or not the change point is a piece of music (step S15). If it is determined that the vicinity of the change point is music, the process returns to step S13.

  If it is determined in step S15 that the change point vicinity is not a song, it is determined that the song has ended, and the current time is stored as the song end time Te (step S16). Since the previous music is recorded, the time counting by the second timer is started (step S17).

  Then, among the reception quality determination data stored in the memory 9, the average value per unit time of the reception quality determination data between the music start time Ts and the music end time Te is calculated, and the obtained average The value is recorded in the recording medium 5 as reception quality data for the currently recorded music content, and the change point detection time information stored in the memory 9 is between the music start time Ts and the music end time Te. Based on each change point detection time information, it generates change point position information consisting of the position of each change point and change point number information consisting of the total number of change points, and records information about the obtained change points at present It is recorded in the recording medium 5 as change point information for the music content being played (step S18).

  Thereafter, when the time measured by the second timer (Timer2) reaches T1 seconds (step S19), the encoding of the audio signal and the storage of the audio signal in the recording medium 5 are stopped (step S20).

  Thereafter, it is determined whether or not the reception quality data (the average value of the reception quality determination data) stored in step S18 is equal to or greater than a predetermined threshold Th (step S21). If the reception quality data is less than the threshold value, it is determined that the reception quality is poor, and the currently recorded music content is deleted (step S22), and then the process proceeds to step S3.

  If it is determined in step S21 that the reception quality data is greater than or equal to a predetermined threshold value, it is determined whether or not the currently recorded music content is recorded in duplicate (step S23). Details of the duplication determination process will be described later.

  If the currently recorded music content is not recorded in duplicate, the process returns to step S3. If it is determined that the music content recorded this time is recorded in duplicate, the one having the poor reception quality is deleted from the two music contents that are duplicated (step S24). For example, of the two overlapping music contents, the one having the smaller reception quality data (the average value of the reception quality determination data) is deleted. In addition, when the music content of the same music and the music content recorded this time are recorded three or more times, the one with the highest reception quality is left among these three or more music contents, and other music contents Is deleted. It should be noted that at least the one with the lowest reception quality may be deleted from among the three or more overlapping music contents other than the one with the highest reception quality. Thereafter, the process returns to step S3.

  In addition, when it is determined that the music content recorded this time is recorded in duplicate, only a portion with good reception quality is connected from a plurality of overlapping music contents, so One piece of music content may be generated, and only the obtained “good place” music content may be recorded.

[2-5] Overlap determination process In the overlap determination process in step S23 of FIG. 2, each song content other than the currently recorded song content recorded on the recording medium matches the currently recorded song content. A match determination process is performed.

  FIG. 3 shows the procedure of the coincidence determination process.

  Here, the music content recorded this time is referred to as first music content, and the music content to be compared with the music content recorded this time is referred to as second music content. , TN, and the positions of the change points of the second music content are S1, S2,..., SM. N is the same integer as the total number of change points of the first music content, and M is the same integer as the total number of change points of the second music content.

  First, a variable n for designating one of a plurality of change points corresponding to the first music content is set to 1 (step S31). Further, a variable m for designating one of a plurality of change points corresponding to the second music content is set to 1 (step S32).

  Then, it is determined whether or not | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is smaller than a predetermined value σ (step S33). That is, the distance (time) from the change point Tn to the change point T (n + 1) in the first music content and the distance (time) from the change point Sm to the change point S (m + 1) in the second music content. It is determined whether or not the absolute value of the difference is smaller than σ.

  If it is determined in step S33 that | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is smaller than the predetermined value σ, n is less than (N−1) and m is (M -1) It is determined whether or not the condition of less than is satisfied (step S38). When the condition that n is less than (N-1) and m is less than (M-1) is satisfied, n is incremented by 1 and m is incremented by 1 (step S39). It is determined whether or not | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is smaller than a predetermined value σ (step S40). If it is determined in step S40 that | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is smaller than the predetermined value σ, the process returns to step S38.

  In step S38, when the condition that n is less than (N-1) and m is less than (M-1) is not satisfied, that is, n is equal to or greater than (N-1) or m Is equal to or greater than (M-1), it is determined that the second music content is the same music as the first music content (step S42). If it is determined in step S40 that | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is equal to or greater than the predetermined value σ, the second music content is the first music content. It determines with it not being the same music (step S41).

  If it is determined in step S33 that | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is equal to or greater than the predetermined value σ, m is incremented by 1 (step S34), It is determined whether m is greater than or equal to M (step S35).

  If m is not greater than or equal to M, that is, if m is less than M, the process returns to step S33, and | {T (n + 1) −Tn} − {S (m + 1) −Sm} | is smaller than the predetermined value σ again. It is determined whether or not.

  If it is determined in step S35 that m is greater than or equal to M, after incrementing n by 1 (step S36), it is determined whether or not n is greater than or equal to N (step S37). If n is not N or more, that is, if n is less than N, the process returns to step S32, and after m = 1, it is again | {T (n + 1) -Tn}-{S (m + 1) -Sm}. It is determined whether or not | is smaller than a predetermined value σ.

  If it is determined in step S37 that n is greater than or equal to N, it is determined that the second music content is not the same music as the first music content (step S41).

  For example, when the positions T1, T2,..., TN of the change points of the first music content and the positions S1, S2,..., SM of the change points of the second music content are at the positions shown in FIG. Will be described. In this case, N = 5 and M = 4.

  First, n = m = 1, and in step S33, it is determined whether or not | (T2-T1)-(S2-S1) | is smaller than a predetermined value σ. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 1 of the first music content and the length of the segment 1 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of the two are different, it is determined that | (T2−T1) − (S2−S1) | is equal to or greater than the predetermined value σ.

  Therefore, after m = 2 is set in step S34, the process returns to step S33, and it is determined whether or not | (T2-T1)-(S3-S2) | is smaller than a predetermined value σ. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 1 of the first music content and the length of the segment 2 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of the two are different, it is determined that | (T2−T1) − (S3−S2) | is equal to or greater than the predetermined value σ.

  Therefore, after setting m = 3 in step S34, the process returns to step S33, and it is determined whether or not | (T2-T1)-(S4-S3) | is smaller than a predetermined value σ. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 1 of the first music content and the length of the segment 3 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of the two are different, it is determined that | (T2−T1) − (S4−S3) | is equal to or greater than the predetermined value σ.

  Therefore, after n = 2 in step S36 and m = 1 in step S32, the process returns to step S33, and whether or not | (T3-T2)-(S2-S1) | is smaller than a predetermined value σ. Determined. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 2 of the first music content and the length of the segment 1 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of both are equal, it is determined that | (T3-T2)-(S2-S1) | is smaller than the predetermined value σ. Accordingly, YES is determined in the step S33, and the process proceeds to the step S38.

  In step S38, it is determined whether or not the condition that n is less than (N-1) and m is less than (M-1) is satisfied. In this case, since (N-1) = 4 and (M-1) = 3, n = 2 <(M-1) = 4 and m = 1 <(M-1) = 3. Therefore, the process proceeds to step S39, where n = 3 and m = 2. In step S40, it is determined whether or not | (T4-T3)-(S3-S2) | is smaller than a predetermined value σ. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 3 of the first music content and the length of the segment 2 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of both are equal, it is determined that | (T4-T3)-(S3-S2) | is smaller than the predetermined value σ. Accordingly, YES is determined in the step S40, and the process proceeds to the step S38.

  In step S38, it is determined whether or not the condition that n is less than (N-1) and m is less than (M-1) is satisfied. In this case, since n = 3 <(N−1) = 4 and m = 2 <(M−1) = 3, the process proceeds to step S39, where n = 4 and m = 3. In step S40, it is determined whether or not | (T5-T4)-(S4-S3) | is smaller than a predetermined value σ. That is, in the example of FIG. 4, it is determined whether or not the length of the segment 4 of the first music content and the length of the segment 3 of the second music content are substantially equal. In the example of FIG. 4, since the lengths of both are equal, it is determined that | (T5−T4) − (S4−S3) | is smaller than the predetermined value σ. Accordingly, YES is determined in the step S40, and the process proceeds to the step S38.

  In step S38, it is determined whether or not the condition that n is less than (N-1) and m is less than (M-1) is satisfied. In this case, since n = (N−1) = 4 and m = (M−1) = 3, NO is determined in step S38, and the second music content is the same music as the first music content. It is determined that there is.

[3] Music playback processing

  FIG. 5 shows a music reproduction processing procedure.

When a normal playback instruction is input after the user selects a music piece to be played back, the selected music data is read from the recording medium 5 (step S51). The music data read from the recording medium 5 is decoded by the DSP 4 and the audio signals are output to the speakers 7 _L and 7 _R via the D / A converter 6 (step S52). Thereby, the music selected by the user is reproduced.

  During music playback, it is monitored whether or not a playback stop instruction has been input. If a playback stop instruction is input during music playback (YES in step S53), the process of reading music data from the recording medium 5 and the decoding process by the DSP 4 are stopped (step S54).

[4] Modified Example In the above-described embodiment, the binarized value of the output voltage of the S meter output terminal is used as the reception quality judgment data, but the following data is used as the reception quality judgment data. be able to.

[4-1] Modification 1

  The FM tuner IC has a function of muting the output sound when the electric field strength of the selected broadcast wave is equal to or lower than a predetermined threshold, and whether or not the output sound is muted. Some devices have a mute drive output terminal for outputting a signal representing.

  As shown in FIG. 6, when such an FM tuner IC is used as the FM tuner unit 102, the electric field strength of the selected broadcast wave is equal to or lower than a predetermined threshold when music content is recorded. Then, silence will be recorded. Therefore, when such an FM tuner IC is used as the FM tuner unit 102, the output signal of the mute drive output terminal 102a is used as reception quality determination data. That is, when music content is recorded, the output signal of the mute drive output terminal 102a is recorded as reception quality determination data. In this case, the reception quality of the music content may be determined on the basis of the ratio of the sum of silent sections to the total time of the music content. The higher the ratio of the sum of silent sections to the total time of the music content, the worse the reception quality of the music content.

[4-2] Modification 2

  Some FM tuner ICs have a function of muting the output sound when the electric field strength of the selected broadcast wave is below a predetermined threshold.

  As shown in FIG. 7, when such an FM tuner IC is used as the FM tuner unit 202, the electric field strength of a received broadcast wave is below a predetermined threshold when music content is recorded. As a result, silence is recorded. Therefore, when such an FM tuner IC is used as the FM tuner unit 202, the DSP 4 is provided with a function of detecting a silent section. And when the music content is recorded, the information (silent section time) indicating the silent section detected by the DSP 4 is recorded as reception quality determination data. In this case, the reception quality of the music content may be determined on the basis of the ratio of the sum of silent sections to the total time of the music content. The higher the ratio of the sum of silent sections to the total time of the music content, the worse the reception quality of the music content.

It is a block diagram which shows the structure of a music recording / reproducing apparatus. It is a flowchart which shows a music recording process procedure. It is a flowchart which shows the matching determination processing procedure used by the duplication determination processing of step S19 of FIG. It is a schematic diagram for demonstrating specifically a coincidence determination process. It is a flowchart which shows a music reproduction | regeneration processing procedure. It is a block diagram which shows the modification of a music recording / reproducing apparatus. It is a block diagram which shows the other modification of a music recording / reproducing apparatus.

Explanation of symbols

2 FM tuner section 3 A / D conversion section 4 DSP
5 Recording Medium 6 D / A Converter 7 _L , 7 _R Speaker 8 A / D Converter 9 Memory 10 CPU

Claims (5)

In a music recording apparatus having a function of receiving a broadcast wave, extracting music content from the received broadcast wave, and recording it on a recording medium,
First means for generating reception quality determination data for determining the reception quality of the broadcast wave being received;
When the recording of the music content is completed, the process determines whether the reception quality of the music content is high or low based on the reception quality determination data generated by the first means while receiving the music content. 2 means, and third means for deleting the music content from the recording medium when it is determined that the reception quality of the music content is low,
It is provided with the music recording device characterized by the above-mentioned. In a music recording apparatus having a function of receiving a broadcast wave, extracting music content from the received broadcast wave, and recording it on a recording medium,
First means for generating reception quality determination data for determining the reception quality of the broadcast wave being received;
When the recording of the music content is completed, the reception of the music content is received from the reception quality determination data generated by the first means while receiving the music content or the data obtained from the reception quality determination data. Second means for storing as quality data; third means for determining whether or not the music content is recorded on the recording medium when recording of the music content is completed; and When recorded on a recording medium, the reception quality of each piece of music content is compared based on the reception quality data of each piece of music content for the same piece of music recorded in duplicate, and the received piece of music content is received. At least the reception quality of the music content other than the highest quality music content Fourth means for deleting the lowest music content from the recording medium,
It is provided with the music recording device characterized by the above-mentioned. The music recording apparatus includes a tuner IC having an S meter output terminal for outputting a signal corresponding to the electric field strength of the broadcast wave being received, and the first means includes a S meter output terminal of the tuner IC. 3. The music recording apparatus according to claim 1, wherein the reception quality determination data is generated based on the output. The music recording device has a function of muting the output sound when the electric field intensity of the received broadcast wave is equal to or lower than a predetermined threshold, and outputs a signal indicating whether or not the output sound is muted. 3. A tuner IC having a terminal, wherein the first means generates reception quality determination data based on an output from a mute drive output terminal of the tuner IC. The music recording device described. The music recording apparatus includes a tuner IC having a function of muting the output sound when the electric field intensity of the received broadcast wave is equal to or less than a predetermined threshold, and the first means records the music content. 3. The music recording apparatus according to claim 1, wherein a silent section is detected from the recorded audio data, and a time that is the silent section is generated as reception quality determination data.

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