RU2246140C2 - Method for addressing recording of bit flow, data carrier and device for recording bit flow on data carrier - Google Patents

Abstract

FIELD: data carriers.

SUBSTANCE: data carrier uses address table, which assigns time information to given data portions and wherein each of said portions includes constant number of bits. Said portions contain data packets, for each input into address table. Each of said portions is assigned with value of duration change in time. Each such value is assigned with current index. Said value is difference between time of receiving first packet of portion data and time of receiving data packet, following directly after last data packet of this portion, to receive value of required address of goal portion on data carrier. All value of duration change in time for portion having said goal address are added to increasing total. Appropriate current index for inputting change of duration in time, related to said closest value of duration in time, is multiplied by given constant number of bits to calculate said address value of goal portion.

EFFECT: higher efficiency.

3 cl, 7 dwg

Description

The present invention relates to a method and apparatus for addressing a stream of bits to be recorded or recorded on a storage medium, such as an optical disc.

State of the art

When writing a bitstream, this bitstream can be arbitrarily divided into subunits of a more regular structure. Presentation data in DVDs (digital video discs or universal digital discs) is organized into blocks called a Video object block, which are abbreviated as VOBU, for example, in the RTRW description for real-time rewritable DVD video discs. VOBU has a variable size (the amount of data measured by the number of sectors), and also has a different duration (measured in the number of video fields). To reproduce data from a disc, the RTRW specification provides for a “VOBU card”, which is a table in which for each VOBU in the record its length in sectors and duration in fields are entered.

EP-A-0729153 describes a table that is used for combined playback mode, wherein in this table a time code is assigned to each sector of the optical disk, which may have a variable transmission speed.

SUMMARY OF THE INVENTION

A table for searching data on a storage medium may be based on bitstream data that is divided into parts of constant duration. "Duration" means the difference between the arrival time of the first packet of the data part and the arrival time of the packet immediately following the last packet of this data part.

An “organization” in the general context of an RTRW record or a stream record is the task of translating a given amount of time (presentation time in the case of RTRW recording or packet arrival time in the case of stream recording) to the address of the disk on which the required data can be found.

In such systems, a VOBU map or “Organizing Address Table”, which stands for HAT, may contain a specific size or a specific offset or a specific size of the delta change or, in general, a specific value of the address type for each of these parts of constant duration. When recording the delta change values instead of the total duration for the current VOBU, these inputs can be described with a shorter word length, which makes it possible to obtain a VOBU card with a reasonable size.

A possible type of organizational process for such systems may include the following steps:

- By dividing and truncating, the index of entry into the table that needs to be viewed is calculated from a given amount of time.

- The content of the entry into the table directly describes the value of the address to which access must be made, or all entries in the table, up to this index, must be summed up with a cumulative total to obtain the value of the address to which access must be made.

A big drawback of this type of HAT, which is based on pieces of data of constant duration, is the following:

- In the case of a low bit rate, when writing part of the data of constant duration will be small, that is, each part will contain only a few data sectors or, in extreme cases, only part of the data sector. A disk can contain a huge number of such parts, so the HAT may become too large to be remembered.

- In the case of a high bit rate, when writing parts of data of constant length will be large in size, that is, each part will contain a large number of data sectors. Therefore, addressing to one part or to another part of the data corresponds to a very coarse addressing on a scale (sector), that is, the address of the part obtained from the HAT may indicate a place spaced a large number of sectors from the current location.

Therefore, organization based on parts of constant duration in some cases can lead to too much HAT (up to half the disk capacity), and in other cases can lead to too coarse addressing.

The aim of the present invention is to describe a method for assigning the address of a data carrier to a given amount of time, and this method does not have these disadvantages. This goal is achieved using the method described in paragraph 1 of the claims.

According to the present invention, the organizing table of the HAT address is based on parts of a constant length or size, that is, on a constant number of bits in a part. In a DVD-RAM drive in which the data is physically organized into “ECC blocks” (ECC: error correction code) each 32 kbytes in size, it is particularly preferred that the above constant size or a multiple thereof be used as the constant size of the data part . However, any other constant size may be used. In the case of constant size data parts, the HAT contains for each of these constant size parts a specific absolute duration, or preferably a specific delta change duration, which indicates the difference in the arrival time of the last and first packets that are contained in this data part. The organization process, that is, the calculation of the required VOBU address, includes the following steps:

- Summing up the cumulative total of the delta duration changes contained in the HAT until the given time value comes closest to the required VOBU, that is, until the sum of the delta duration changes is less than or equal to the specified time value, taking into account, that the VOBU inputs are scanned forward, or until the sum of the delta duration changes is greater than or equal to a given amount of time, provided that the VOBU inputs are scanned back.

- The current index of entry into this table, multiplied by the constant size of the data part, directly leads to the value of the address to be accessed.

The advantages of a HAT based on constant size in accordance with the present invention are as follows:

- The HAT size is independent of the write bit rate.

- The HAT addressing accuracy is constant, the degree of partitioning generally corresponds to a “constant part size” that can be selected appropriately so that it is constant for all types of disks, can be constant for one disk, or constant for a particular record on a particular drive.

In principle, the method in accordance with the present invention is suitable for addressing a bit stream to be recorded or recorded on a storage medium, for example, a DVD recorder that uses an address table that is based on parts of the specified bit stream, and in which:

- each of these parts includes a constant number of bits of the specified bit stream;

- each input in the address table for the indicated parts is assigned an absolute time duration or a change in the delta time duration in the specified address table using the current index;

- in the case of recording absolute values of the duration of time:

to obtain the address value for accessing the desired address, the nearest corresponding input of the absolute duration of the specified address table is selected, and the corresponding current index is multiplied by the specified constant number in order to calculate the specified address value, or,

- in the case of recording the values of the delta duration of time:

to obtain the address value for accessing the target address, all delta time duration changes up to the nearest time duration corresponding to the specified address value are summed up with a cumulative total, and the current index corresponding to the delta time change input related to the specified nearest time is multiplied by the specified constant value for calculating the specified address value.

Preferred additional embodiments of the method in accordance with the present invention are described in the respective dependent claims.

Brief Description of the Drawings

Embodiments of the present invention are described with reference to the accompanying drawings, in which:

1 is a simplified block diagram of an entire DVD stream recording system;

figure 2 - the root directory and file structure;

figure 3. - navigation data structure;

4 is a flow packet;

5 is an organizing table of addresses in accordance with the present invention;

6 is a flow time map information;

7 is an example of a display list.

Examples of embodiments

The DVD stream recording system is designed to use rewritable DVD discs to record existing digital bit streams, edit them and play them as a bit stream.

The following abbreviations are used:

LB: Logical Block, RBN: relative byte number, RBP: relative byte position, RLBN: relative logical block number, STB: electronic device, TOC: table of contents, SCR: system clock frequency.

This system is designed so that it meets the following requirements:

Any packet size is supported as long as it is less than 2 KB and has a constant length within the sample.

The synchronization mechanism, that is, a time stamp is added to each transmitted packet to ensure the correct transmission of the packet during playback.

To expand the scope, it should be possible to record not in real time. However, in this case, the STB must generate time stamp information.

The data placement strategy and file support real-time stream recording.

Many digital services require service information, which is usually entered into the stream in real time. To maintain the STB into which data is received from the DVD player, additional space must be allocated to the DVD, which can be used by the STB to duplicate part of the service information and to add additional TOC information.

Copy protection must be supported. In addition, any permutation of elements that is performed by a service provider or STB must be maintained without change.

User requirements can be grouped into recording requirements, playback requirements, and editing requirements:

Real time recording

The system should be designed so that it allows real-time recording of digital streams. It should also allow the user to join records, even if these records consist of different stream formats. If the recordings are combined, it would be desirable to provide imperceptible or near imperceptible reproduction at the junction, but this requirement is not necessary.

Navigation Support

To support navigation during recording, two pieces of information (lists) must be generated:

1) "Original" is the version of the playlist. This list contains relatively low level information, such as a time map or the order (transmission) of recording packets. This list can be accessed using the STB, and its contents are understandable for the DVD streamer, as well as for the STB. In the original version, the list allows you to play the entire recording. Access to the playlist can be made and expanded after recording using the STB to obtain a more complex playback sequence.

2) The second piece of information, a display list, is generated to support the device that records the stream, to play portions (cells) of the packet stream, which are described as application domains, such as “packets for transmission” or “time”. This list is owned and understood only by the DVD streamer.

Content Description

The system should leave space that can be used by the STB to accumulate TOC information and high-level service information. This information is provided to the user to navigate through the contents of the disc entries, and may contain extended GUI (graphical user interface) information. There is no need for the content to be understood by streaming devices. However, it may be useful to make a common part of the TOC information, for example, based on a character string, so that it is common between the STB and the DVD, so that the recording device can form the main menu itself.

Playback of individual recordings and sequential playback of all recordings should be done using a playlist.

Playback menu for selecting entry points

The STB may generate advanced menus based on TOC information recorded on a disc. However, it should also provide the ability to generate simple menus using the tape drive itself, for example using some information recorded as “characters” that is common to STB and DVD.

Combined Play Modes

The STB should be able to control combined playback using a “playlist”. Due to the nature of the stream being transmitted, the properties of the combined playback may be limited by the basic properties, for example, time search or skipping over names.

User-defined playlist properties, as well as programming or parental control, can be supported using a playlist.

The DVD streamer should create an “original version” of the playlist. It should also allow the expansion and modification of the playlist using the STB for advanced playback capabilities. The DVD streamer is not responsible for the contents of such an expanded playlist (s).

The system should support erasure of individual entries at the request of the user. If possible, the system should implement this property under the control of the STB. The system can support insertion type editing.

In the simplified general system of FIG. 1, an application device AD communicates via an IF interface, such as an IEEE 1394 type interface, with a streamer device STRD, that is, a DVD writer. The streamer STR in the STRD device sends its data through the output means for buffering and setting temporary stamps BTNO to IF and receives data from IF through the input means for processing buffering and setting temporary stamps in BTHI. AD sends its data through the output buffering and temporary stamp processing tool BTHOAD to IF and receives data from IF through the input means for buffering and temporary stamping BTHIAD.

With respect to the directory and file structure, the organization of the stream data and navigation data in a DVD stream record is performed in a specific way, such that takes into account the following points:

- Any DVD streamer device STRD has some requirements regarding the accumulation of its own organizational data or navigation data related to this tape drive on the disc. This data is used exclusively for reproducing recorded data; they should not be understood and should not even be visible to any external device of the AD application.

- Any DVD streamer device STRD must communicate with the AD device of the application to which it is connected. Such a connection should be so universal that the maximum possible range of applications can be connected to the tape drive. The navigation data to maintain such a connection is called general navigation data and should be understood by the tape drive, as well as by the application devices.

- The streamer device STRD should offer the connected AD application device a means to accumulate its own data of any desired form. The streamer should not understand the content, internal structure or meaning of this data related to the navigation of the application.

Figure 2 shows a possible directory structure and file structure in which all the data constituting the contents of the disk is recorded. Files in which the contents of the disc are recorded are located in the STRREC directory, which is located in the root directory. The following files are created in the STRREC directory:

- COMMON.IFO

Basic information for describing the contents of a stream. It must be understood by the application device, as well as the tape drive.

- STREAMER.IFO

Private overhead related to the streamer device. Its understanding of the application device is not required.

- APPLICAT.IFO

The private data of the application, that is, information that relates to the application (s) connected to the tape drive. Her understanding of the streamer is not required.

- REALTIME.SOB

Correctly recorded real-time data stream.

It should be noted that in addition to the files described above, the STRREC directory should not contain any other files or directories.

Regarding the structure of the navigation data, the navigation data is intended to control the recording, reproduction and editing of any bit streams that are recorded. As shown in FIG. 3, navigation data includes flow control information (SMI), which is contained in a file called COMMON.IFO and overhead information (HKPI), which is contained in a file called STREAMER.IFO. From the point of view of the streamer device, there are two types of information that is sufficient to perform all necessary operations.

In addition to these, recording a DVD stream also provides for the possibility of reserving recording locations for private application data (APD), which can also generally be regarded as navigation data.

SMI and HKPI are navigation data that directly relates to the operation of the tape drive. SMI includes three kinds of information tables, namely general flow control information (SM_GI), stream name table (STT) and stream playlist table (SPLT), in that order. HKPI includes two types of information tables, namely General Organization Information (HKP-GI) and Organizational Address Table (HAT), in that order.

When recording a stream, there is no restriction that each table of navigation information must be consistent with the boundaries of the sectors.

SM_GI includes information elements such as SMI end address, SM_GI end address, STT start address, and SPLT start address.

The STT includes information items such as the number of stream names, the end address of the stream name table, application packet size, service identifier, application device identifier, stream duration, stream name search index, stream header names (STN).

The SPLT includes information elements such as the number of playlists, the end address of the SPLT, the start addresses of the play information, the number of entries in the playlist, the index of the stream name, the beginning of the SCR, and the end of the SCR.

General overhead information (HKP_GI) includes information points such as the number of organizational address inputs (HAE_Ns), the HKPI end address (NKI_EA), and the timeline factor (HKP_TSCAL).

HAE_Ns describes the number of organizational address entries contained in this HKPI. NKRI_EA describes the end address of this HKPI. HKP_TSCAL describes the timeline used in this HKPI.

The organizational address table (HAT) in accordance with the present invention is intended to generate all the necessary information so that the inputs of this playlist are effectively translated into pairs of disk addresses, and vice versa.

It is also possible to include private application data, which consists of three types of information, namely general information of private application data, a set of one or more search pointers for private application data, and a set of one or more areas of private application data. If any private application data exists, these three types of information are recorded and stored in that order in the APPLICAT.IFO file.

Stream data includes one or more "stream objects" (SOBs), each of which can be written as a "program stream", as described in ISO / IEC 13818-1 systems.

SOB may end with a program end code (program_end_code). The SCR field in the first packet of each SOB may not be zero. The SOB contains stream data packaged as sequences of "stream packets" (S_PCK). Stream data can be organized as a single elementary stream and are contained in PES packets (programmable electronic systems) with a stream identifier (stream_id).

As shown in FIG. 4, a stream packet includes a packet header, which is ultimately followed by a system header, and followed by one stream packet (S_PCT). The system header may be included in those S_PCs that represent the first S_PCK in the SOB. When the system header is enabled, the length of the rest of the stream packet consists of 2010 bytes, when it is not included, the length of the contents of the stream packet is 2034 bytes.

A stream object consists of one or more stream packets.

The HAT table shown in FIG. 5 contains, for each part, either the VOBU (VOBU # I-VOBU # N) bit stream to be recorded, or the recorded bit stream, corresponding absolute or delta inputs ADUR # 1-ADUR # N for the length of time. DAV indicates the desired address or destination address of the bitstream. Each of VOBU # 1-VOBU # N contains a constant number of stream bits.

The HAT table may be in the STMAPI flow time map information format and may include two subunits: "General flow time map information" STMAP_GI and one "MAPL map split list". Possible contents of STMAPI are presented in FIG. 6. MAPU_SZ describes the size in sectors of blocks of the map splitting list. The size of the map block, for example 16 sectors, means that the first input of the map list refers to the application packets contained in the first 16 sectors of the stream, the second input of the map list refers to the application packets contained in the next 16 sectors and so on.

MTU_SHFT describes the weight of the LSB entries of the map list with respect to the packet arrival time (PAT) bits of the description format. MTU_SHFT describes a value from 16 to 36. For example, a value of “16” means LSB (the least significant bit) of the arrival time of the incremental packet of the IAPAT application has the same weight as PAT_BASE [0], so PAT_BASE [x] means the value of the base PAT, which is measured in blocks of 90 kHz. MTU_SHFT depends on MAPU_SZ. MTU_SHFT satisfies the following conditions:

and

in which max_bitrate = maximum bit rate in the MPEG-2 program stream.

MAPL_ENT_Ns describes the number of map list entries to follow after STMAP_GI.

S_S_ARAT describes the beginning of the arrival time of the application packet of the stream, that is, the arrival time of the packet for the first packet belonging to the stream.

S_E_ARAT describes the end of the arrival time of the application packet of the stream, that is, the arrival time of the packet for the last packet belonging to the stream.

The MAPL mapping list consists of zero or more IAPAT “incremental application packet arrival times”. IAPAT describes the incremental arrival time of the application package of the corresponding card blocks in a format that describes the incremental PAT of a DVD stream record, defined as follows:

Let MAPU_S_APAT (i), 1≤i≤MAPL_ENT_Ns be the beginning of the arrival time of the application package of the card block number i, that is, the time of receipt of the packet for the first packet belonging to the card block number i; let MAPU_E_ARAT (i) be the last arrival time of the application package of card block number i, that is, the time of arrival of the packet for the last packet belonging to card block number i and let IAPAT (i) be the ith input of the IAPAT list of the card, that is, IAPAT (1 ) represents the first entry of the map list. Then IAPAT (i) must satisfy the following conditions:

for i = 1, 2, ..., MAPL_ENT_Ns-1,

and

for i = MAPL_ENT_Ns,

and

0≤IAPAT (i) <2 ¹²

for i = 1, 2, ..., MAPL_ENT_Ns.

7 shows an example of the order of MAPU, MAPU_S_APAT, MAPU_E_APAT and IAPAT. The lower side of time t is divided into IAPAT time blocks and the upper side of the t axis is MAPU.

MAPU_S_APAT (i) and MAPU_E_APAT (i) are described in a format that describes PAT records of a DVD stream. For comparison, in the above equations, MAPU_S_APAT (i) and MAPU_E_APAT (i) are processed as, for example, constants of 6 bytes unsigned.

Duration IAPAT = 1 represents

секунд.Time block

seconds.

When recording a stream, the application performs its own addition of free space in the memory block with insignificant information so that there is no need to use methods for adjusting the length of a DVD-ROM Video or RTRW packet. When recording a stream, it is safe to assume that packets will always have the required length.

The data stream also contains time stamps, for example within data packets.

Claims (7)

1. The method of addressing the parts (VOBU # i) of the bit streams to be recorded or recorded on the data carrier (STRD), which uses the address table (HAT), which assigns time information to the indicated data parts and in which each of the indicated parts (VOBU #i) includes a constant number of bits, characterized in that the indicated parts contain data packets, for each entry in the address table of each indicated part, in the indicated address table (HAT) is assigned a value of a change in time duration (ΔDUR # i), and each change amount keep In time, the current index (i) is assigned, and the amount of change in duration in time is the difference between the time of arrival of the first data packet of the part and the time of arrival of the data packet immediately following the last data packet of this part; to obtain the value of the required address (DAV) of the target part on the specified storage medium, all values of the change in duration in time for the part having the specified target address are summed up in cumulative total and the corresponding current index (i) to enter the change in time duration related to the specified nearest duration value in time, multiplied by the specified constant number of bits in order to calculate the specified value of the address of the target part. 2. The method according to claim 1, characterized in that the storage medium (STRD) is a streamer device or a DVD writer. 3. The method according to any one of claim 1 or 2, characterized in that the size of the data part corresponds to the number of bits of the ECC block or is a multiple thereof. 4. A storage medium containing parts (VOBU # i) of the bitstream and a table (HAT) of addresses that assigns time information to the indicated parts, each of these parts (VOBU # i) including a constant number of bits, characterized in that the indicated parts contain data packets; for each entry in the address table of the indicated parts, the duration change in time (ΔDUR # i) is assigned in the specified address table (HAT) and the current index (i) is assigned to each change in duration in time, while the change in duration in time represents the difference between the time of arrival of the first data packet of the part and the time of arrival of the data packet immediately following the last data packet of this part; in this case, all values of the change in duration in time for the part having the specified destination address can be summed up on an accrual basis and the corresponding current index (i) to enter the change in duration in time related to the specified nearest value of the duration in time can be multiplied by the indicated constant number of bits to calculate the specified address value (DAV) of the target part on the specified storage medium. 5. A device (STRD) for recording a bit stream on a data medium or reproducing a bit stream from a data medium in which the address table (HAT) is used to address the parts (VOВU # i) of the specified bit stream, which assigns time information to the indicated parts, and in wherein each of the indicated parts (VOBU # i) includes a constant number of bits organized into data packets, characterized in that said device includes: a memory that stores an address table (HAT), in which each input to the address table is assigned a value changed I of duration in time (ΔDUR # i) and each value of change in duration in time is assigned the current index (i), while the value of change in duration in time is the difference between the time of arrival of the first data packet of the part and the time of arrival of the data packet immediately following the last packet data of this part; means for calculating the address value (DAV) of the target part on the specified storage medium, in which all values of the change in duration in time for the part having the specified target address are summed up on an accrual basis, and the corresponding current index (i) for entering the change in duration in time related to the specified nearest value of the duration in time, multiplied by the specified constant number of bits in order to calculate the specified value of the address of the target part. 6. The device according to claim 5, characterized in that the device is a streamer device or a DVD writer. 7. The device according to any one of claim 5 or 6, characterized in that the size of the part corresponds to the number of bits of the ECC block or is a multiple thereof.

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