KR19980053617A - Audio deshuffling device for digital video cameras - Google Patents

Abstract

In the present invention, a digital video camera (DVC) is used to deshuffle the shuffled audio data to disperse the burst error of the recording and reproduction system of the digital audio signal to the original sample number. The present invention relates to an audio deshuffling apparatus, which sequentially obtains a word number, a sync number, a track number, and a byte weight from audio data of a shuffled frame to perform a deshuffling operation.

Therefore, the present invention is simplified in configuration and has a high operating speed, so that real-time processing is easy.

Description

Audio Deshuffling Apparatus for Digital Video Camera

In the present invention, a digital video camera (DVC) is used to deshuffle the shuffled audio data to disperse the burst error of the recording and reproduction system of the digital audio signal to the original sample number. It relates to an audio deshuffling apparatus.

In general, audio encoding modes in digital audio cameras for digital video cameras are supported in four formats: two 48-kHz, 44.1-kHz, and 32-kHz and four-channel 32-kHz modes, depending on the product.

The encoded two-channel or four-channel digital audio data is stored in units of frame and randomly converted when a cluster error occurs in the audio data track.

That is, the audio data is recorded on the magnetic recording tape by rearranging the order so that blocks of the input digital audio data are included in the same segment. This is called shuffling.

To avoid clustering errors, audio samples and dummy data are shuffled in one frame. The positions are track number (TN), sync block number (SBN), and byte position number (BPN). The track number, sync number, and byte position number are determined by certain specifications.

For example, according to the specification of the 48KHz 525/60 system two-channel mode, the track number, sync block number, and byte position number are determined according to the rules shown in the following equation.

[Equation 1]

TN = (int (Dn / 3) + 2 x (Dn MOD 3)) MOD 5 ---- 1st channel

TN = (int (Dn / 3) + 2 x (Dn MOD 3)) MOD 5 + 5 ---- 2nd channel

[Equation 2]

SBN = 3 x (Dn MOD 3) + int ((Dn MOD 45) / 15)

[Equation 3]

BPN = 2 x int (Dn / 45) ----- Upper Byte

BPN = 2 x int (Dn / 45) + 1 ----- Lower Byte

In the above equation, Dn is a sample number, that is, a sequential number, and MOD is a Modulo operation.

The pattern shown by shuffling in the 48 KHz mode by such a rule is as shown in FIG.

When the track number TN is '0' or '5', the shuffling pattern as shown in Fig. 1A according to the sync block number SBN (i) and the byte position number BPN (j). When the track number TN is '1' or '6', as shown in Fig. 1B according to the sync block number SBN (i) and the byte position number BPN (j). If the track number TN is '2' or '7' when the track number is a shuffling pattern, the synchronization block number SBN (i) and the byte position number BPN (j) are shown in Fig. 1 (C). If the track number TN is '3' or '8', as shown in Fig. 1, according to the sync block number SBN (i) and the byte position number BPN (j). ), And the track number TN is '4' or '9', depending on the sync block number SBN (i) and byte position number BPN (j). It becomes a shuffling pattern as shown to 1 (e).

Accordingly, a process of shuffling an audio sample will be described with reference to FIG. 1.

The 48KHz 525/60 two-channel mode system consists of 10 tracks of the frame, divided into five tracks in the first half and the second half to record channel 1 on the first five tracks and channel 2 on the second five tracks.

Therefore, the first audio sample (D0) of the two channels is recorded in the tenth and eleventh bytes of the second sync block of the tracks '0' and '5', and the second audio sample (D1) of the two channels is '2'. And the tenth and eleventh bytes of the fifth sync block of the '7' track, and the third audio sample (D2) of the two channels is the tenth and eleven of the eighth sync block of the '4' and '9' tracks. The fourth audio sample (D3) of the two channels is recorded in the tenth and eleventh bytes of the second sync block of the '1' and '6' tracks, and the fifth audio sample (D4) of the two channels. ) The 10th and 11th bytes of the 5th sync block of the '3' and '8' tracks are recorded.

According to this specification, each audio sample Dn is shuffled by being recorded. For this shuffling, the audio sample Dn input according to the above equations (1), (2), and (3). Was calculated.

As such, the audio data of one frame shuffled by the shuffling rules set forth in the DVC SD specification must be recovered to the original sample number through deshuffling during playback.

Therefore, in the digital video camera, the present invention provides a digital video camera to sequentially obtain word numbers, sync numbers, track numbers, and byte weights from audio data of one shuffled frame so as to simplify a circuit and have a high processing speed. It is an object to provide a shuffling device.

1 is a typical shuffling pattern

2 is a block diagram of an audio deshuffling apparatus according to the present invention

FIG. 3 is a diagram for describing an operation of a synchronous decoder of FIG. 2.

4 is a flowchart illustrating a decoding operation of the track and sync number decoder of FIG. 2.

Explanation of symbols for the main parts of the drawings

100: word number extraction unit 101, 102, 110, 120: counter

130: multiplier 140: synchronous decoder

150: Track and Sync Number Decoder

In order to achieve the above object, an audio deshuffling apparatus of a digital video camera according to the present invention comprises: a word number extracting unit for counting shuffled audio sample data by a specific word unit according to a channel mode to extract a word number; A first counter for counting a word number output from the word number extracting unit by 9 units and outputting a sync block number; A second counter for outputting a track number by counting a sync block number output from the first counter by 10 units; A multiplier for multiplying a word number output from the word number extracting unit by 4 to output a byte position number; A sync decoder which decodes a sync block number output from a first counter and a byte position number output from the multiplier as an input to extract a sync weight; And a track for decoding the sync block number output from the first counter, the track number output from the second counter and the sync weight output from the sync decoder to output deshuffled audio sample data. Characterized in that the synchronization number decoder.

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

The audio deshuffling apparatus of the digital video camera according to the present invention includes a word number extractor 100, a counter 110, 120, a multiplier 130, a sync decoder 140, and a track and And a synchronization number decoder 150.

The word number extracting unit 100 extracts the word number WN by counting the shuffled audio sample data sDn in units of specific words according to a channel mode, and in the case of a two channel mode, the shuffled audio sample A counter 101 for counting data sDn in 35 word units and outputting a word number WN, and in the case of 4-channel mode, counting the shuffled audio sample data sDn in 24 word units so that a word number ( And a counter 102 for outputting WN).

The counter 110 counts the word number WN output from the word number extracting unit 100 in units of 9 and outputs a sync block number SBN.

The counter 120 counts the sync block number SBN output from the counter 110 in units of 10 and outputs a track number TN.

The multiplier 130 outputs a byte position number BPN by multiplying a word number WN output from the word number extracting unit 100 by 4, and outputs from the word number extracting unit 100. And a shifter for shift writing the word number WN by two bits.

The sync decoder 140 decodes the sync block number SBN output from the counter 110 and the byte position number BPN output from the multiplier 130 as inputs to synchronize weights SW. ), And when the sync block number SBN output from the counter 110 is 0, the byte position number BPN output from the multiplier 130 is converted into a sync weight SW. If the sync block number SBN outputted from the counter 110 is 1, 15 is added to the byte position number BPN outputted from the multiplier 130 to synchronize the weight. If the sync block number (SBN) output from the counter 110 is 2, 30 is added to the byte position number (BPN) output from the multiplier (130) to synchronize weight (SW). ) And output from the counter 110 When the sync block number SBN is 3, 10 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight SW, and output from the counter 110. When the sync block number SBN is 4, 25 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight SW, and from the counter 110. When the output sync block number SBN is 5, 40 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight SW, and the counter 110 is output to the counter 110. When the sync block number SBN outputted from 6 is 6, 5 is added to the byte position number BPN output from the multiplier 130, and the counter is outputted as a sync weight SW. When the sync block number (SBN) outputted from 7 is 7, the multiplier 130 The multiplier 130 adds 20 to the byte position number BPN that is output from the output unit as a sync weight (SW), and outputs the sync block number SBN outputted from the counter 110 to the multiplier 130. It decodes by adding 35 to the byte position number (BPN) outputted from the output to the sync weight (SW).

The track and sync number decoder 150 outputs a sync block number SBN output from the counter 110 and a track number TN output from the counter 120 and the sync decoder 140. Outputting deshuffled audio sample data dDn by decoding the synchronization weight SW to be input, and the track number TN output from the counter 120 is 2 or 7 and the counter 110 When the sync block number SBN outputted from is 3 or 4, -9 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn. When the track number (TN) output from the counter 120 is 2 or 7 and the sync block number (SBN) output from the counter 110 is not 3 or 4, the sync decoder 140 Deshuffle by adding 6 to the output sync weight (SW) The track number TN output from the counter 120 is 3 or 8 and the sync block number SBN output from the counter 110 is 3 or 5, respectively. In this case, -6 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn, and the track number TN output from the counter 120. Is 3 or 8 and the sync block number SBN output from the counter 110 is not 3 or 5, deducting by adding 9 to the sync weight SW output from the sync decoder 140. And the track number TN output from the counter 120 is 4 or 9, and the sync block number SBN output from the counter 110 is 3, 4, or the like. In the case of any one of 5, 6, 7, and 8, the output from the sync decoder 140 Add -3 to the pre-weight SW to output the deshuffled audio sample data dDn, and the track number TN output from the counter 120 is 4 or 9 and is sent to the counter 110. If the sync block number SBN outputted from the apparatus is not one of 3, 4, 5, 6, 7, and 8, 12 is added to the sync weight SW output from the sync decoder 140, and then deshuffled. Outputs the ringed audio sample data dDn and deshuffles the sync weight SW output from the sync decoder 140 when the track number TN output from the counter 120 is 0 or 5. If the track number TN output from the counter 120 is 1 or 6, 3 is added to the sync weight SW output from the sync decoder 140. Add and decode to output the deshuffled audio sample data dDn.

The operation of the audio deshuffling apparatus of the digital video camera according to the present invention configured as described above will be described.

First, the word number extracting unit 100 extracts the word number WN by counting the audio sample data sDn shuffled by a specific word unit according to a channel mode.

That is, the counters 101 and 102 of the word number extraction unit 100 perform a counting operation according to the channel mode signal. In the two-channel mode, the counter 101 operates to shuffle the shuffled audio sample data. Counting (sDn) in units of 35 words to output word number (WN), and in 4-channel mode, the counter 102 operates to count the shuffled audio sample data (sDn) in units of 24 words. Outputs the number WN.

The word number WN output from the word number extraction unit 100 is counted in units of 9 in the counter 110 and output as a sync block number SBN to synchronize the decoder 140, the counter 120, and The track and sync number decoder 150 are output.

The counter 120 counts the sync block number SBN output from the counter 110 in units of 10 to output a track number TN. The multiplier 130 outputs the word number extractor 100. Shift bit writes the word number WN outputted from the 2-bit bit and outputs the byte position number BPN.

The sync block number SBN output from the counter 110 and the byte position number BPN output from the multiplier 130 are decoded by the sync decoder 140 to obtain a sync weight SW. Extracted.

That is, in the sync decoder 140 as shown in FIG. 3, the sync decoder 140 outputs different values according to the sync block number SBN output from the counter 110. It is added to and output as a sync weight (SW).

When the sync block number SBN output from the counter 110 is 0, the byte position number BPN output from the multiplier 130 is output as a sync weight SW, and the counter ( When the sync block number SBN outputted from 110 is 1, 15 is added to the byte position number BPN outputted from the multiplier 130 and output as a sync weight SW. When the sync block number SBN output from 110 is 2, 30 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight SW.

In addition, when the sync block number SBN output from the counter 110 is 3, 10 is added to the byte position number BPN output from the multiplier 130 to a sync weight SW. If the sync block number SBN outputted from the counter 110 is 4, 25 is added to the byte position number BPN outputted from the multiplier 130, and a sync weight SW is obtained. If the sync block number SBN outputted from the counter 110 is 5, 40 is added to the byte position number BPN outputted from the multiplier 130, and a sync weight SW is obtained. )

In addition, when the sync block number SBN outputted from the counter 110 is 6, 5 is added to the byte position number BPN outputted from the multiplier 130 as a sync weight SW. If the sync block number SBN outputted from the counter 110 is 7, 20 is added to the byte position number BPN outputted from the multiplier 130 to sync weight SW. If the sync block number SBN outputted from the counter 110 is 8, 35 is added to the byte position number BPN outputted from the multiplier 130 and the sync weight SW is obtained. )

The sync weight SW decoded and output by the sync decoder 140 is input to the track and sync number decoder 150 together with the track number TN and the sync block number SBN to be decoded. It is output as ringed audio sample data dDn.

That is, the track and sync number decoder 150 outputs a sync block number SBN output from the counter 110 and a track number TN output from the counter 120 and the sync decoder 140. The de-shuffled audio sample data dDn is output by decoding the synchronous weight SW output as shown in FIG. 4 as an input, which will be described in detail.

First, the track number TN output from the counter 120 is searched and then the sync block number SBN is searched to output the corresponding deshuffling audio sample data dDn.

In other words, if the track number TN is 2 or 7 (200), and if 2 or 7 is detected, the sync block number SBN output from the counter 110 is 3 or 4 (201). If the sync block number SBN is 3 or 4, -9 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn (202). ). In addition, when the track number (TN) output from the counter 120 is 2 or 7 and the sync block number (SBN) output from the counter 110 is not 3 or 4, the sync decoder 140 is transmitted. The subtracted -9 is added to the synchronous weight SW outputted from the output signal and output as deshuffled audio sample data dDn (203).

In addition, if the track number TN is not 2 or 7, the search result 200 searches whether the track number TN is 3 or 8 (204). If the track number TN is 3 or 8, it is output from the counter 110. It is searched whether the sync block number SBN is 3 or 5 (205). In this case, when the sync block number SBN is 3 or 5, -6 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn (206). ). In addition, when the track number (TN) output from the counter 120 is 3 or 8 and the sync block number (SBN) output from the counter 110 is not 3 or 5, the sync decoder 140 is sent to the sync decoder 140. 9 is added to the synchronization weight SW outputted from the output signal and output as deshuffled audio sample data dDn (207).

In addition, if the track number TN is not 3 or 8, the search result 204 searches whether the track number TN is 4 or 9 (208). The synchronous block number SBN is searched for any one of 3, 4, 5, 6, 7, and 8 (209). At this time, if the sync block number SBN is any one of 3, 4, 5, 6, 7, and 8, -3 is added to the sync weight SW output from the sync decoder 140 to deshuffle. And outputs the audio sample data dDn (210). The track number TN output from the counter 120 is 4 or 9, and the sync block number SBN output from the counter 110 is 3, 4, 5, 6, 7, and 8. If not one, 12 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn (211).

Further, if the track number TN is not 4 or 9, the search result 208 searches whether the track number TN is 0 or 5 (212), and outputs it from the sync decoder 140 if it is 0 or 5. The synchronization weight SW is output as deshuffled audio sample data dDn (213).

When the track number TN is not 0 or 5, the track number TN is 1 or 6. Accordingly, when the track number TN is 1 or 6, 3 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn (214).

The audio sample data sDn of one frame shuffled by the extracted track number TN, the sync weight SW and the sync block number SBN is deshuffled and the audio sample of one frame is shuffled. The data is output as dDn.

As described above, the audio deshuffling apparatus of the digital video camera according to the present invention is simplified in configuration and has a high operating speed, thereby facilitating real-time processing.

Claims (5)

A word number extracting unit 100 which counts the shuffled audio sample data sDn in units of specific words according to a channel mode and extracts a word number WN; A first counter (110) for counting the word number (WN) output from the word number extracting unit (100) in units of 9 and outputting a sync block number (SBN); A second counter 120 for counting the sync block number SBN output from the first counter 110 in units of 10 and outputting a track number TN; A multiplier 130 for multiplying the word number WN output from the word number extractor 100 by 4 to output a byte position number BPN; A sync decoder that decodes a sync block number SBN output from the first counter 110 and a byte position number BPN output from the multiplier 130 to extract a sync weight SW. 140; And The sync block number SBN output from the first counter 110, the track number TN output from the second counter 120, and the sync weight SW output from the sync decoder 140. And a track number for outputting deshuffled audio sample data (dDn) by decoding to an input and a sync number decoder (150). The third counter 101 of claim 1, wherein the word number extractor 100 counts the shuffled audio sample data sDn in 35 word units and outputs a word number WN in the 2-channel mode. ); And a fourth counter 102 for counting the shuffled audio sample data sDn in units of 24 words and outputting a word number (WN) in the 4-channel mode. Ring device. 2. The audio deshuffling of a digital video camera according to claim 1, wherein the multiplier (130) comprises a shifter for shifting the word number (WN) output from the word number extractor (100) by two bits. Device. The sync decoder 140 of claim 1, wherein the sync decoder 140 outputs the byte position number BPN output from the multiplier 130 when the sync block number SBN output from the first counter 110 is 0. If the sync block number SBN outputted from the first counter 110 is 1 and the sync block number SBN is 1, 15 is assigned to the byte position number BPN outputted from the multiplier 130. Is added to output a sync weight (SW), and when the sync block number SBN output from the first counter 110 is 2, the byte position number BPN output from the multiplier 130 is added. ) Is added to 30 and output as a sync weight (SW), and the byte position output from the multiplier 130 when the sync block number SBN output from the first counter 110 is 3 Add 10 to the number BPN and output it as Sync Weight SW. When the sync block number SBN output from the first counter 110 is 4, 25 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight SW. When the sync block number SBN outputted from the first counter 110 is 5, 40 is added to the byte position number BPN outputted from the multiplier 130, and a sync weight SW is obtained. ) And if the sync block number SBN output from the first counter 110 is 6, 5 is added to the byte position number BPN output from the multiplier 130 to synchronize the sync weight. Weight: SW) and if the sync block number SBN output from the first counter 110 is 7, 20 is added to the byte position number BPN output from the multiplier 130 to synchronize. Output as a weight (Sync Weight: SW), and is output from the first counter 110 If the block number SBN is 8, the audio of the digital video camera characterized in that 35 is added to the byte position number BPN output from the multiplier 130 and output as a sync weight (SW). Deshuffling device. 2. The sync block of claim 1, wherein the track and sync number decoder 150 has a track number TN of 2 or 7 output from the second counter 120 and is output from the first counter 110. If the number SBN is 3 or 4, -9 is added to the sync weight SW output from the sync decoder 140 and output as deshuffled audio sample data dDn, and the second counter ( When the track number TN output from 120 is 2 or 7 and the sync block number SBN output from the first counter 110 is not 3 or 4, it is output from the sync decoder 140. 6 is added to the synchronization weight SW to be output as deshuffled audio sample data dDn, and the track number TN output from the second counter 120 is 3 or 8, and the first counter ( If the sync block number SBN output from 110 is 3 or 5, the sync decoder 140 And -6 is added to the sync weight SW outputted from the output signal as deshuffled audio sample data dDn, and the track number TN output from the second counter 120 is 3 or 8. When the sync block number SBN output from the first counter 110 is not 3 or 5, 9 is added to the sync weight SW output from the sync decoder 140 to deshuffle the audio sample data. (DDn), the track number TN output from the second counter 120 is 4 or 9, and the sync block number SBN output from the first counter 110 is 3, 4, In the case of any one of 5, 6, 7, and 8, -3 is added to the sync weight SW output from the sync decoder 140, and output as deshuffled audio sample data dDn. The track number TN output from the second counter 120 is 4 or 9 and is output from the first counter 110. When the block number SBN is not one of 3, 4, 5, 6, 7, and 8, the deshuffled audio is added by adding 12 to the sync weight SW output from the sync decoder 140. Output the sample data dDn and deshuffle the sync weight SW output from the sync decoder 140 when the track number TN output from the second counter 120 is 0 or 5. Outputs the audio sample data dDn, and when the track number TN output from the second counter 120 is 1 or 6, 3 is added to the synchronization weight SW output from the synchronization decoder 140. And outputting the deshuffled audio sample data (dDn) by adding.