KR100249768B1 - Method for transmitting a transport packet element in a digital video home system - Google Patents

Abstract

A transport packet element transmission method is disclosed in which the time stamp indicating the arrival time of the first byte of a packet element is damaged in the digital video home system type video cassette recorder and thus the transmission of the transport packet element is stopped. Even-numbered tracks and odd-numbered tracks each having a plurality of transport packet elements are stored in the first and second storage areas, respectively, and then all transport packet elements of one track are transmitted in synchronization with the transition state of the switching pulse. The transport packet elements of the track being transmitted are still transmitted when the transition state of the switching pulse is determined and not transitioned. When the switching pulse transitions, it is determined whether the flag is generated. When the flag is generated, the storage area switching enable signal is generated to stop the transmission of the current track, and the track following the track where the transmission was stopped is transmitted. When no flag is generated, it is determined whether the transmission of the track being transmitted is completed. When the transfer is completed, of the plurality of tracks stored in the first and second storage areas, a track following the track where the transfer is completed is transmitted. In other words, when the time stamp of any transport packet element is corrupted, the remaining transport packet elements of the track containing the damaged transport packet element are discarded and the next track is transmitted. Therefore, the transmission blocking phenomenon of the transport packet elements of the track due to the damage of the time stamp is eliminated.

Description

Transport Packet Element Transmission Method in Digital Video Home System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video home system (hereinafter referred to as 'DVHS'), and more particularly, to a transport packet element due to a damage of a time stamp. The present invention relates to a method for transmitting a transport packet element in a digital video home system, which prevents the transmission of a " TPE "

Digital data propagated via satellite from a broadcasting station is selected through a tuner of a set top box, and input into DVHS through an IEEE 1394 digital interface. In this case, the input data is bit-serially input in the form of a Transport Packet Element (hereinafter referred to as 'TPE') composed of 188 bytes.

1 is a block diagram for explaining the step of transmitting a transport packet element in a digital video home system type video cassette recorder. 2 is a diagram showing a general transmission time of a transport packet element in a digital video home system type video cassette recorder.

1 and 2, a method for smoothing and disposing a conventional transport packet element will be described.

First, a plurality of transport packet elements A1, A2, A3, and A4 composed of 188 bytes input through a tuner of a set top box (not shown) are sequentially transferred to a time stamp generator 10. Is entered. The time stamp generator 10 generates time stamps t1, t2, t3, and t4 composed of four bytes representing the input time to each of the plurality of transport packet elements A1, A2, A3, and A4. Write a time stamp to the transport packet element.

Subsequently, 192 bytes of data having a time stamp added to the transport packet element are sequentially stored in a smoothing buffer 20. In the smoothing buffer 20, dummy data is attached to each transport packet element in order to convert the plurality of transport packet elements to have a constant bit rate. The plurality of transport packet elements having the constant bit rate are stored in a data storage medium such as a memory device, a magnetic tape, and a CD-ROM.

Next, a process of transmitting the transport packet data stored in the data storage medium to the set top box is as follows.

First, transport packet elements sequentially stored in the data storage medium are input to a smoothing buffer 40 to remove dummy data added to each transport packet element in the smoothing buffer 20.

Subsequently, when transport packet elements are input to a time stamp comparator 50, the time stamp comparator 50 compares the time stamp value of each transport packet element with a current reference time stamp value. Controls the transmission time of the packet element.

However, according to the conventional method as described above, the time stamp of the transport packet element stored in the data storage medium 30 via the smoothing buffer 20 causes a tape scratch in the case of an error of the data storage medium, for example, magnetic tape. ), Contamination of the magnetic tape by contaminants, and the elongation and contraction of the magnetic tape may cause the recording of the time stamp to be corrupted or misrecognized.

For this reason, there arises a case where the input time of the transport packet element inputted first has a value larger than the input time of the inputted transport packet element.

In other words, in FIG. 2, if the time stamp 't2' indicating the input time of the transport packet element 'A2' is damaged and the value of 't2' is larger than 't3' and smaller than 't4', the absolute criteria already set Over time, a transmission break occurs in the system that transmits the transport packet element.

Therefore, the overflow of the smoothing buffer 40 not only stops the transmission of the transport packet element, but also causes a serious problem in which the entire system malfunctions.

The present invention proposed to solve the above problems provides a method for transmitting a transport packet element in a digital video home system that can prevent transmission of the transport packet element by interruption of a time stamp. The purpose is.

1 is a block diagram for explaining the step of transmitting a transport packet element in a digital video home system type video cassette recorder.

2 is a view showing a general transmission time of a transport packet element in a digital video home system type video cassette recorder.

3 is a diagram showing ideal transmission control of a transistor packet element in a digital video home system type video cassette recorder.

Fig. 4 shows the column structure of an ideal smoothing buffer in a digital video home system type video cassette recorder.

5 is a timing diagram for explaining a transmission control method of a transport packet element when a transmission error occurs in a digital video home system type video cassette recorder.

6 is a flowchart showing a transport packet element transmission method in a digital video home system type video cassette recorder according to an embodiment of the present invention.

7 is a flowchart showing in more detail the flag generation step shown in FIG.

* Explanation of symbols for main parts of the drawings

10: time stamp generator 20: smoothing buffer

30: data storage medium 40: smoothing buffer

50: timestamp comparator

According to the present invention for achieving the above object, a transport packet element transmission method in a digital video home system comprises the steps of: reading and transmitting transport packet elements of any one of a plurality of stored tracks; Determining a transition state of the switching pulse to continuously transmit a transport packet element of a track being transmitted or to determine whether a flag is generated; Stopping transmission of the transport packet element of the current track in response to a storage area switching enable signal, and transmitting the transport packet element of the track following the stopped transmission track; And when it is determined that no flag is generated, transmitting transport packet elements of a track following the transmitted track among the stored plurality of tracks according to whether the transport packet element of the track being transmitted is completed. Is done.

According to the transport packet element transmission method in such a digital video home system, if the time stamp of any transport packet element is corrupted, the remaining transport packet elements of the track including the damaged transport packet element are discarded and Send the transport packet element of the track. Therefore, the transmission of the transport packet element is interrupted due to the damage of the time stamp, thereby preventing the overflow of the smoothing buffer, thereby solving a problem such as malfunction of the entire system.

Best Mode for Carrying Out the Invention Preferred embodiments of the present invention will now be described in detail with reference to Figs.

FIG. 3 shows ideal transmission control of transport packet elements in a digital video home system type video cassette recorder according to an embodiment of the present invention, and FIG. 4 shows a column structure of an ideal smoothing buffer.

3 and 4, a plurality of tracks composed of a plurality of transport packet elements read from a data storage medium for reproducing data are divided into a first storage area Q1 and a second storage area Q2 of the smoothing buffer. ) Are stored alternately. Accordingly, even-numbered tracks i, i + 2, i + 4 are sequentially stored in the first storage area Q1, and odd-numbered tracks i + 1, are stored in the second storage area Q2. i + 3, i + 5) are stored sequentially.

Each track i, i + 2, i + 4, i + 1, i + 3, i + 5 stored in the first and second storage areas Q1 and Q2 is transmitted in synchronization with the transition of the switching pulse. .

Ideally, as shown in Fig. 3, transport packet elements constituting one track are transmitted during the pulse width of one switching pulse, and the next track during the pulse width of the next switching pulse when the switching pulse transitions. Transport packet elements of are transmitted.

Accordingly, while the switching pulse 'SP1' is generated, the transport packet elements TPi, 0-TPi, mi of the earliest stored track i of the first storage area Q1 are transmitted, and the switching pulse transitions to switch. While the pulse 'SP2' is generated, the transport packet elements TPi + 1,0-TPi + 1 and mi + 1 of the track i + 1 stored first in the second storage area Q2 are transmitted.

Similarly, the tracks i + 2, i + 3, i + 4, i + 5 are also transmitted alternately during the width of one switching pulse in synchronization with the transition of the switching pulses.

This time, a transmission method of a transport packet element in a digital video home system according to an embodiment of the present invention will be described with reference to FIGS.

5 is a timing diagram illustrating a transmission control method of a transport packet element when a transmission error occurs, and FIG. 6 is a flowchart illustrating a transmission method of a transport packet element. 7 shows the flag generation step shown in FIG. 6 in more detail. In Fig. 5, reference numeral 'A' denotes a transport packet element having a damaged time stamp.

First, a plurality of tracks (i, i + 1, i + 2, i + 3, i + 4, i + 5) composed of a plurality of transport packet elements are shown in FIG. 3 and FIG. The data is stored alternately in the second storage areas Q1 and Q2 (step S110).

When the data stored in step S110 are reproduced, the tracks i, i + 1, i + 2, and i + stored in the first and second storage areas Q1 and Q2 in response to the switching pulse SP1. Among the 3, i + 4, i + 5), the transport packet element (TPi, 0-TPi, mi) of the earliest inputted and stored track i, i. Step S120).

Next, it is determined whether the switching pulse SP1 has transitioned (step S130), and when the switching pulse 'SP1' is in progress, the transport packet elements TPi (0-TPi, mi) of the track i being transmitted. Continue to be transmitted (step S140).

When the switching pulse SP1 transitions to generate the next switching pulse SP2, it is determined whether a flag is generated at the time when the switching pulse transitions (step S150).

If no flag is generated, it is determined whether the transmission of the transport packet elements (TPi, 0-TPi, mi) of the track (i) currently being transmitted is completed (step S190), and the transport packet of the track (i) being transmitted. When the elements TPi, 0-TPi, mi are not transmitted, step S190 is repeatedly performed.

When the transport packet elements TPi, 0-TPi, mi of the current track i are completed, the plurality of tracks i, i + 1, i + stored in the first and second storage areas are completed. Among the 2, i + 3, i + 4 and i + 5, the transport packet element of the track 'i + 1' of the second storage area Q2 corresponding to the next track of the track i currently being transmitted ( TPi + 1, 0-TPi + 1, mi + 1) (step S180).

In addition, when a flag is generated in step S150, as shown in FIG. 5, a storage area switching enable signal is generated at the time when the switching pulse transitions (step S160). In response to the storage area switching enable signal, transmission of the transport packet elements TPi, 0-TPi, mi of the track i being transmitted is stopped (step S170).

Therefore, when the time stamp of the third transport packet element 'TPi, 2' of the track 'i' shown in FIG. 4 is corrupted, the remaining transport packet elements (TPi, 3-TPi, mi) of the track 'i' are damaged. They are not transmitted but are lost.

Then, the transport packet elements TPi + 1, 0-TPi + 1, mi + 1 of the track 'i + 1' of the second storage area Q2 corresponding to the next track of the track i whose transmission has been stopped. ) Is transmitted (step S180).

A method of determining whether a flag is generated in the above-described transmission method of a transport packet element will be described in more detail with reference to FIG. 7.

Referring to FIG. 7, when transport packet elements of a particular track are transmitted in synchronization with a switching pulse, the system input time difference between the transport packet element currently being transmitted and the next transport packet element, that is, between two transport packet elements. The time difference of the type stamp is calculated (step S151).

If the input time difference does not exceed the reference set value (step S155), and if the input time difference does not exceed the reference set value, step 155 is repeatedly performed. If the input time difference exceeds the reference set value, a flag is generated as shown in Fig. 5 (step S157).

The flag also occurs at the point when the transport packet element with a corrupted time stamp is transmitted until the switching pulse transitions and is maintained until a storage area switching enable signal is generated.

According to the transport packet element transmission method in the digital video home system as described above, if the time stamp of any transport packet element is corrupted, the remaining transport packet elements of the track including the damaged transport packet element are discarded. And transmits a transport packet element of the next track.

Therefore, the transmission of the transport packet element is interrupted due to the damage of the time stamp, thereby preventing the overflow of the smoothing buffer, thereby solving a problem such as malfunction of the entire system.

Claims (6)

(A) reading and transmitting transport packet elements of any one of a plurality of stored tracks; (B) determining a switching pulse and a transition state to continuously transmit a transport packet element of a track being transmitted or to determine whether a flag is generated; (C) stopping transmission of the transport packet element of the current track in response to a storage area switching enable signal and transmitting the transport packet element of the track following the interrupted track; And (D) When it is determined in step (B) that a flag is not generated, a track following the transmitted track among the plurality of tracks stored in step (A) depending on whether the transport packet element of the track being transmitted is completed. And transmitting the transport packet elements of the transport packet element in the digital video home system. 2. The method of claim 1, wherein step (A) comprises: (a) storing even and odd tracks, each having a plurality of transport packet elements, in different storage areas; And (b) a method of transmitting a transport packet element in a digital video home system, comprising reading and transmitting transport packet elements of one track included in a plurality of tracks stored in step (a) . The method of claim 1, wherein the step (B) comprises: (c) determining whether the switching pulse is in a transition state; (d) when it is determined in step (c) that the switching pulse is not in a transition state, continuing to transmit a transport packet element of the transmitting track; And (e) when it is determined in step (c) that the switching pulse is in a transition state, determining whether a flag is generated or not. 2. The method of claim 1, wherein step (C) comprises: (f) generating a storage area switching enable signal when it is determined in step (B) that a flag is generated; And (g) stopping transmission of the transport packet element of the current track in response to the storage area switching enable signal generated in step (f), and among the plurality of tracks stored in step (A), And transmitting a transport packet element of a subsequent track. The method of claim 1, wherein the step (D) determines whether or not the transmission of the transport packet element of the track being transmitted is completed when it is determined in step (B) that the (h) flag is not generated. ; (i) when it is determined in step (h) that the transfer is not completed, continuing to perform step (h); And (j) when it is determined in step (h) that transmission has been completed, transmitting transport packet elements of a track following the transmitted track among the plurality of tracks stored in step (A). A method of transmitting a transport packet element in a digital video home system. 2. The method of claim 1, wherein said steps comprise: (i) calculating an input time difference between a transport packet element being transmitted and a next transport packet element; (ii) continuing to perform step (i) when it is determined that the input time difference exceeds a reference set value and is determined not to exceed the reference set value; And and (iii) generating a flag when it is determined in step (ii) that the input time difference exceeds a reference set value.

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