HK1116575B - Information storage medium storing multiangle data, and recording method and reproducing apparatus thereof - Google Patents

Description

Information storage medium storing multi-angle data, and recording method and reproducing apparatus thereof

The present application is a divisional application of a patent application having an application date of 2004, 7/6, application No. 200480002849.7 entitled "information storage medium storing multi-angle data, and recording method and reproducing apparatus therefor".

Technical Field

The present invention relates to multi-angle data used when encoding and/or decoding video object data, and more particularly, to an information storage medium storing the multi-angle data, a method of recording and/or reproducing the multi-angle data, and an apparatus for recording and/or reproducing the multi-angle data.

Background

Multi-angle data is obtained by photographing a scene with several cameras at different angles and encoding the photographed results. When it is desired to change the viewing angle of a photographed scene during reproduction of content including multi-angle data, an angle change command is transmitted to a reproducing apparatus, and the reproducing apparatus reproduces data of the scene photographed at a desired angle in response to the command. For angle change, multi-angle data is divided into predetermined units and the units are alternately recorded using interleaving.

Therefore, a pickup of a reproducing apparatus must jump to other positions in order to detect and reproduce interleaved blocks at one angle or to complete angle change while reading multi-angle data recorded using interleaving. However, an increase in the size of the interleaved blocks results in an increase in the distance between the current position and the position to which the pickup of the reproducing apparatus must jump for angle change. In this case, seamless reproduction is not guaranteed. In contrast, if the size of the interleaved block is small, jumping of a pickup of a reproducing apparatus is frequently required during data reproduction that does not require angle change. Therefore, it is important to appropriately adjust the size of the interleaved block.

Also, jumping points allowing the reproducing apparatus to jump to other interleaved blocks at different angles may be disposed within one interleaved block. In this case, the total number of jumping points must be properly determined so that the multi-angle data is efficiently reproducible.

Disclosure of Invention

The present invention provides an information storage medium having multi-angle data recorded thereon to allow seamless reproduction, and a method of recording and/or reproducing the multi-angle data and an apparatus for recording and/or reproducing the multi-angle data.

The present invention also provides a method of determining a total number of angle points that allow a reproducing apparatus to jump to change a reproducing position within an interleaved block.

As described above, according to the present invention, multi-angle data can be efficiently recorded so that multi-angle data can be seamlessly reproduced without excessive jumping of a pickup for data reproduction.

Drawings

FIG. 1A illustrates a first angle data file;

FIG. 1B illustrates a second angle data file

FIG. 1C illustrates recording first and second angle data files using interleaving;

FIG. 2 illustrates the multi-angle data of FIG. 1 recorded on an information storage medium;

fig. 3 is a block diagram of a reproducing apparatus for seamlessly reproducing data according to an embodiment of the present invention;

FIG. 4 is a diagram showing some of the data stored in the read buffer during a jump of the pickup;

FIG. 5 illustrates a structure of a clip file recorded using interleaving to implement multi-angle data according to an embodiment of the present invention; and

FIG. 6 is a diagram of calculating a distance S between two angle points according to an embodiment of the present invention_{ANGLE_POINTS}And length S of range (extension)_EXTENTA flow chart of the method of (1).

Detailed Description

According to an aspect of the present invention, there is provided an information storage medium having recorded thereon multi-angle data including at least one unit of angle data, wherein the multi-angle data includes interleaved blocks, each of the interleaved blocks includes at least one packet of a predetermined size, and data of one angle is interleaved with data of at least one other angle in units of the interleaved blocks, the size of the interleaved blocks being an integral multiple of the size of an integral number of aligned units including the packet.

Each interleaved block may include at least one angle point allowing a reproducing apparatus to continue data reproduction while jumping to other reproduction positions during reproduction of angle data, and the number of angle points included in each interleaved block may be an integral multiple of the number of aligned units.

According to another aspect of the present invention, there is provided a method of recording multi-angle data including interleaved blocks using interleaving, each interleaved block including at least one angle point allowing a reproducing apparatus to jump to other reproduction positions during data reproduction, the method including: calculating the distance between the angle points; compensating for an offset between the calculated distance and a reproduction length of a packet including each interleaved block; calculating a maximum number of angle points in one interleaved unit obtained when a longest jump distance to which the reproducing apparatus can jump during data reproduction is less than or equal to a maximum jump distance given by the reproducing apparatus; and making interleaved blocks based on the distance between the angle points and the number of angle points, and recording the multi-angle data on the interleaved blocks.

According to another aspect of the present invention, there is provided an apparatus for reproducing multi-angle data stored in interleaved blocks, each interleaved block including at least one angle point allowing the apparatus to jump to other reproduction positions during data reproduction, the apparatus comprising: a reading unit which reads multi-angle data; and a buffer storing the read multi-angle data, wherein the multi-angle data includes interleaved blocks, each of the interleaved blocks includes at least one packet of a predetermined size, and angle data of one angle is interleaved with angle data of at least one other angle in units of the interleaved blocks, the size of the interleaved blocks being an integral multiple of the size of an integral number of aligned units including the packet.

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

FIGS. 1A-1C illustrate multi-angle data recorded using interleaving. The multi-angle data includes a first angle data file 110 as shown in fig. 1A and a second angle data file 120 as shown in fig. 1B containing audio/video (AV) data for respective angles. For a rapid change of the angle view, the first and second angle data files 110 and 120 are alternately and continuously recorded in an area 130 of the information storage medium as shown in fig. 1C. In other words, the first and second angle data files 110 and 120 are divided into predetermined units, and the predetermined units are recorded using interleaving. Accordingly, when the angle view is changed, it is not necessary for the pickup of the reproducing apparatus to move a large distance to read data at the changed angle, thereby guaranteeing seamless reproduction.

A predetermined unit of each angle data included in the data recorded on the information storage medium using interleaving is referred to as a range. In the case of digital versatile disc-VIDEO (DVD-VIDEO), the range is equal to the interleaved units. That is, the extent indicates data recorded in the file system without a pause. Therefore, for data reproduction, it is necessary for the pickup of the reproducing apparatus to jump to other ranges for accurately reading data.

Fig. 2 illustrates the interleaved data of fig. 1A-1C recorded on an information storage medium 200. The AV stream represents a bit stream including a plurality of source packets. The source packet is a 192 byte packet including a 188 byte MPEG-2 Transport Stream (TS) and a 4 byte packet header. Generally, data is stored in sector units of an information storage medium. A sector is a basic unit of recording a file. Typically, the sectors stored in a DVD are 2048 bytes long. Thus, one sector is composed of a plurality of source packets.

Fig. 3 is a simplified block diagram of a reproducing apparatus for seamlessly reproducing data. Referring to fig. 3, data stored in an information storage medium is read by a reading unit 310, and the read data is transferred to a read buffer 330 via a demodulation unit 320. The read buffer 330 is used to buffer the bitstream to be transmitted to the decoder, and thus, the use of the buffer guarantees seamless reproduction even during jumping of the pickup 305 in the read unit 310. The source depacketizer 340 converts a bitstream including a plurality of source packets into MPEG-2TS packets and outputs the MPEG-2TS packets.

The parameters related to buffering are as follows:

(a)R_UD: via demodulation unit 320The data rate of the data transferred from the read unit 310 to the read buffer 330;

(b)R_TS: maximum value of coding rate TS _ recording _ rate of MPEG-2TS, i.e., speed of outputting data to the decoder;

(c)R_MAX: maximum bit rate of the source packet stream. The MPEG-2TS packet is 188 bytes long and a 4-byte packet header is included in the MPEG-2TS packet to form a source packet stream. Thus, the maximum bit rate R_MAXEqual to (192/188)' R_TS。

Assume data B output from read buffer 330 to the decoder at speed TS _ recording _ rate_OCCUPIEDSatisfies equation 1 even when at time T_JUMPData cannot be stored in the read buffer 330 and underflow of the read buffer 330 does not occur.

Fig. 4 is a diagram showing some of the data stored in the read buffer 300 during a jump of the pickup 305. In FIG. 4, T_JUMPIndicating jump time, i.e. access time T_ACCESSAnd the time T required to read two Error Correction Codes (ECC)_OVERHEADThe sum of (1). I.e. T_JUMP＝T_ACCESS+T_OVERHEADAnd T is_OVERHEAD(ms)≤{2 x ECC(byte)/R_UD(bps)}。

When data stored in the information storage medium is read, the read buffer 330 is filled with the read data. Before the pickup jumps to a new position, it must be counted as specified in equation (1)The read buffer 330 is filled accordingly to prevent underflow of the read buffer 330. That is, in order to prevent underflow of the read buffer 330, the length S of data that must be read to the read buffer 330 before a jump of the pickup_READEquation (2) must be satisfied.

...(2)

Fig. 5 illustrates a structure of a clip file recorded using interleaving to implement multi-angle data.

As described above, each angle data of one angle is interleaved in the angle data of at least one other angle to reduce a response time for angle change, thereby changing the angle seamlessly. As a result, jumping is required not only for angle change but also for normal playback at the same angle in order to detect and reproduce desired angle data. The interleaved blocks are considered to be the extent of the clip file. The range may include a plurality of angle points that allow the pickup to jump to other angle data. Therefore, the length S of the range in units of sectors_EXTENTAnd the distance S between two angle points_{ANGLE_POINTS}Equation (3) must be satisfied.

The clip file of multi-angle data shown in FIG. 5 has the following limitations:

(i) the fragment files must be located in one layer;

(ii) the range of multi-angle streams must start with an angle point and be aligned in aligned units. If the last aligned unit of the range is not completely filled with the input transport stream, the unoccupied space of the last aligned unit is filled with empty packets;

(iii) each distance S_{ANGLE_POINT}Is an integer multiple of the length of the source packet, e.g., an integer multiple of 192 bytes; and

(iv) length of range S_EXTENThe total number of angle points in the range, and the angle change time must comply with the buffer occupancy rules defined in equations (1) and (2). Examples of buffer parameters are shown in tables 1 and 2 below.

Distance S between two angle points_{ANGLE_POINTS}Length of specific range S_EXTENTShort, and obtains an access time T for angle change when jumping from a current angle point in a current unit of angle data to a farthest angle point in a next unit of angle data_ACCESSIs measured. The angle data unit may refer to a plurality of blocks of data corresponding to the same time, wherein each block corresponds to data of a respective angle.Referring to FIG. 5, data angle 1-1, angle 2-1, and angle 3-1 may be considered the current unit of angle data, and data angle 1-2, angle 2-2, and angle 3-2 may be considered the next unit of angle data. If an angle change command is received before reaching an angle point 520 after the angle point 510, an access time T is obtained when jumping from a last angle point 520 of the angle 1-1 to a first angle point 530 of the angle 3-2 after reproducing the remaining data of the angle 1-1_ACCESSIs measured.

The length S in FIG. 4 if several angle points are set within the range_READIs equal to the distance S_{ANGLE_POINTS}. In this case, equation (2) may be expressed as follows:

FIG. 6 is a diagram illustrating calculation of a distance S between two angle points according to an embodiment of the present invention_{ANGLE_POINTS}And length of range S_EXTENTA flow chart of the method of (1). Referring to FIG. 6, equation (3) is used for a given access time T_ACCESSAnd the data output speed TS _ recording _ rate calculates the distance S_{ANGLE_POINTS}(S610). Next, for 500ms and 1000msThe lengths a and B of the data reproduced at the data output speed TS _ recording _ rate are calculated, respectively (S620). Since the distance between groups of pictures (GOPs) is between 500ms and 1000ms according to the MPEG-2 standard, the distance between angle points is preferably set between 500ms and 1000 ms. Thereafter, a distance S_{ANGLE_POINTS}Is compared with the lengths a and B (S630). If the distance S is_{ANGLE_POINTS}Length A is less than or equal to length S_{ANGLE_POINTS}Is determined to be equal to the length A, and if A < the distance S_{ANGLE_POINTS}Length B is less than or equal to length S_{ANGLE_POINTS}Is determined to be equal to the length B (S630).

Next, the longest jump distance satisfying less than (<) for a given access time T is calculated_ACCESSThe maximum number M of angle points in the interleaved units of the maximum jump distance (S640). Since the available maximum jump distance of the reproducing apparatus is set by the reproducing apparatus, the maximum jump distance is set by passing 2 ' (angle number-1) ' M ' S_{ANGLE_POINTS}And (4) calculating. Thus, the maximum number M may be calculated using the calculated longest jump distance. Thereafter, the length of the range S_EXTENTEqual to INT' 3 and having M angle points.

In view of jumping between two angle points, angle units each corresponding to data between two angle points in one angle data unit are preferably aligned in sectors.

Tables 1 and 2 show the length S of the range calculated using the above method_EXTENTAnd the distance S between two angle points_{ANGLE_POINTS}Examples of values of (c). In detail, table 1 shows the length S when a scene is photographed at three angles_EXTENTAnd a distance S_{ANGLE_POINTS}Examples of values of (c). Table 2 shows the length S when a scene is photographed at nine angles_EXTENTAnd a distance S_{ANGLE_POINTS}Examples of values of (c).

TABLE 1

TS_recording_rate	Maximum jump distance
				10000 sectors (T)ACCESS：210ms)	20000 sectors (T)ACCESS：270ms)	40000 sectors (T)ACCESS：330ms)
	SEXTENTAnd SEXTENTNumber of angle points and length
				20Mbps	2496，4，500ms	4989，8，500ms	9975，8，1sec
24Mbps	2247，3，500ms	4491，3，1sec	8979，6，1sec
				30Mbps	1872，1，1sec	3741，2，1sec	9351，5，1sec

TABLE 2

TS_recording_rate	Maximum jump distance
				10000 sectors (T)ACCESS：210ms)	20000 sectors (T)ACCESS：270ms)	40000 sectors (T)ACCESS：330ms)
	SEXTENTAnd SEXTENTNumber of angle points and length
				20Mbps	624，1，500ms	1248，2，500ms	2496，2，1sec
24Mbps	N.A.	N.A.	1497，1，1sec
				30Mbps	N.A.	N.A.	1872，1，1sec

Typically, the extent of the file is aligned in sectors. According to the present invention, the source packet is 192 bytes long and therefore cannot be aligned with a sector of 2048 bytes. Thus, three consecutive sectors are grouped into one access unit. The three sector access unit is the smallest unit in which an integral multiple of the length of the source packet is equal to the length of the access unit. In other words, in the case where one sector has a length of 2048 bytes, the length of 32 source packets is equal to the length of three sectors, i.e., one access unit.

The present invention may be implemented as a computer program. In this case, codes and code segments, which are the means of the present invention, can be easily derived by computer programmers in the art to which the present invention pertains. Also, the computer program may be stored in a computer readable medium. When the computer program is read and executed by a computer, a method of recording multi-angle data is completed. The computer readable medium may be any medium such as a magnetic recording medium, an optical recording medium, and a carrier wave medium.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims (1)

1. An apparatus for reproducing multi-angle data, the multi-angle data causing the apparatus to display data at an angle selected from a plurality of angles of the multi-angle data during data reproduction, the apparatus comprising:

a reading unit reading multi-angle data per data unit; and

a buffer storing the read multi-angle data,

wherein:

the multi-angle data includes a plurality of interleaved blocks, each interleaved block including at least one packet having a predetermined size;

each interleaved block is aligned in aligned units;

the size of each interleaved block being an integral multiple of the size of the data unit and also an integral multiple of the size of the packet, each interleaved block including at least one angle point enabling the apparatus to continue data reproduction while jumping from one reproduction position to another during reproduction of the multi-angle data,

wherein the reading unit reads data while jumping from one reproduction position to another reproduction position during reproduction of the multi-angle data and the apparatus continues reproducing the read data by using the at least one angle point included in each of the interleaved blocks,

each angle cell corresponding to data between two angle points is aligned in data cells.