MXPA00004819A - Method for marking digital data - Google Patents

Abstract

According to the invention a method is proposed introducing a temporarily erased flag and two offset values (TE_S_OFF, TE_E_OFF) in order to indicate a cell to be temporarily erased and exactly address the Stream Object Units (SOBU), which can be erased completely. Permanent erasure on the fly without any additional view into the streams or quick permanent erasure can be achieved. Advantageously the temporarily erasure can be withdrawn completely also.

Description

METHOD FOR MARKING DIGITAL DATA Description of the invention The invention relates to a method for marking data from a digital data stream representing video or audio information. Background In the recording of serial bit sequences, one has the freedom to subdivide the bit stream into subunits of more regular structure. The presentation data on the DVDs (Digital Video Disc or Versatile Digital) are organized into units known as Unit of Video object, designated as VOBU, for example, in the specifications' DVD for video recording. The VOBUs have a variable size (number of data measured in number of sectors), but they also have a variable duration (measured in number of video fields). For the recovery of data from the disc, the DVD specifications for video recording provide a "VOBU map", which is a table in which for each VOBU of a recording the length in sectors and the duration in fields are recorded. Invention It is an object of the invention to disclose a method for marking digital data as temporarily erased so that permanent erasure can be achieved on the fly without further examination of the sequences. In accordance with the invention this object is achieved by the features specified in the independent claims. Suitable designs and improvements are specified in the dependent claims. The structure of the directory and the DVD Sequence Recording files are organized into Sequence Data and Navigation Data of the DVD Sequence Recording as follows: Any Sequencing Device (of bit sequences) of DVD has certain requirements to store in the disc your own navigation data specific to the Sequencer. This data is only to aid in the recovery of recorded data; it is not necessary to be understandable or even visible to any external application device. Any DVD Sequencer Device needs to communicate with the application device to which it is connected. This communication should be direct and as universal as possible, so that the maximum possible number of applications can be connected to the Sequencer - both now and in the future. The Navigation Data to support this communication must be understood by both the Sequencer and the Application Device; in the following, they will be called "Common Navigation Data". The Sequencing Device should offer the connected Application Device the ability to store its own private data of any desired type. It is not necessary for the Sequencer to understand the content, internal structure or meaning of these "Application Specific Navigation Data". The Navigation Data is provided to control the recording, playback and editing of any bit sequences that are recorded. In DVD Sequence Recording, the Navigation Data is called "Sequencer Information" (STRI). The STRI consists of six types of information tables, specifically Sequencer Information for the Video Governor (STR_VMGI), Sequence File Information Table (SFIT), Original Program Sequence Information (0RG_PGCI), Sequence Information of Program Defined by the User (UD_PGCI), Governor of Text Data (TXT_DT_MG), and Governor of Private Data of the Application (APD_MG). The Sequence File Information Table contains the information on which site of the recording elements the sequence data is recorded. The Original Program Sequence Information serves as a playlist that contains all the shots that were made. A shot is defined in that it contains the information between a start action and a stop action in the recording sequence, also called a program of the ORGJPGCI. Additionally, a Sequence Object (SOB) contains a complete take or part of a take. With both tables the data can be recovered for playback. The Program Sequence Information Defined by the User contains information defined by the user. In order to access more accurately, a program contains one or more cells. A cell indicates Sequence Object Units (SOBU), and each SOBU is assigned an Increased Arrival Time - to the Application Package (IAPAT). According to the invention, in addition to a temporarily deleted TE flag, two displaced values are introduced in order to indicate a SOBU that can be completely erased in order to store additional information. In order to access exactly the SOBUs that can be completely erased, two displaced values (TE_S_0FF and TE_E_0FF) will be added to the flag of the type cell (C_TY). The exact location of these SOBUs is obtained through an Arrival Time of the Sequence Cell Start Application Package (SC_S_APAT), an APAT at the End of the Sequence Cell (SC_E_APAT), a mapping list (MAPL) and these two additional trips TE_S_0FF, TE_E_0FF. For example, the calculation of the start of the first SOBU temporarily deleted begins with a rough location via the SC_S_APAT and the MAPL. MAPL search results in 2 possible positions of the assigned SOBU, for example SOBU #m or SOBU # m + l. In order to define precisely whether the SC_S_APAT is the first application pack of a SOBU, the displaced value TE_S_0FF contains the additional displacement necessary with values 0, 1 or 2 to locate the desired SOBU with respect to the coarse result of the search via MAPL. According to the invention, the structure of the C TY byte is as follows: b7 b6 b5 b4 b3 b2 bl bO C_TY1 TE TE_S_0FF TE_E_OFF C TY1. 010b 'will be described for all sequence cells. TE * 0b ': This cell is the "normal" state. TE_S_0FF and TE_E_0FF will be set to 'OO'. ? lb ': This cell is the condition "temporarily deleted" .. TE_S_OFF ... 00b',? 01b ',? 10b': The first TE SOBU starts the TE_S_OFF SOBUs later than the SOBU number calculated by SC_S_APAT via of the MAPL. * llb ': reserved TE_E_OFF ... 00b',? 01b ', * 10b': The SOBU number of the first SOBU after the last TE SOBU of the TE cell starts the TE_E_OFF SOBUs later than the calculated SOBU number by SC_E_APAT via the MAPL. ? llb ': reserved Drawings The embodiments of the invention are described with reference to the appended drawing which shows: in figure 1 temporary deletion and subsequent permanent deletion; in Figure 2 TE and subsequent additional TE and reconstruction of the first TE cell. Exemplary Modalities The exemplary embodiments of the invention are explained in more detail in the following description. Figure 1 shows a temporary deletion with a subsequent permanent deletion of the part only temporarily deleted.

Figure 2 shows a temporary erasure with a subsequent second temporary erasure behind the part only temporarily erased. The gray parts mark the non-presentable TE parts of the sequence. The dark gray parts mark the complete SOBUs temporarily erased. Figure 1 shows TE and permanent deletion seen from the SOBU level. In the upper part of the drawing designated "original program", a program #j contains a cell #k with an SC_S_APAT and a SC_E_APAT. Cell #k contains several SOBUs from SOBU # 1 to SOBU # 6. Each SOBU is assigned an Increased Application Package Arrival Time (IAPAT). In the central part designated "after TE" the part marked with gray of the program #j is marked as temporarily erased, for example by a user or based on established parameters. The program #j now contains 3 cells from cell #k to cell # k + 2. Cell #k and cell # k + 2 can be reproduced, while cell # k + l is given an erasure flag. Cell # k + l contains a gray TE part that was decided to be erased and a smaller gray TE cell that can be used for later recordings. Cell #k is assigned a new SC_E_APAT and cell # k + 2 a new SC S APAT. Cellk + l is assigned a new SC_S_APAT and also a new SC_E_APAT. The. SC_S_APAT of cell # k + l is smaller than the SC_E_APAT of cell #k, and SC_E_APAT of cell # k + l is smaller than SC_S_APAT of cell # k + 2. In the lower part designated "after permanent deletion" the program #j only contains two cells, which are cell #ky and cell #k + l (previous cell #k + 2), while the cell TE of cell # k + l previous was deleted. The SOBUs of each cell, #k and # k + l, were renumbered, as were the assigned IAPATS. As shown in this example, a small area marked with gray remains in the bit sequence and can not be used to record additional data. After the permanent deletion, the Sequence File Information, the Original Program Sequence Information and the Program Sequence Information Defined by the User. Flight reuse of TE cells during recording. The TE cells contain 2 displaced values: TE_S_OFF and TE_E_OFF. The real intention of these two phase shifts is to allow the TE SOBUs to be used again during recording,. that is, when the disk becomes full during recording, then the sequencer must be able to permanently erase the TE cells in order to obtain new free SOBUs to continue without interruption with the recording. The APATs SC_S_APAT and SC_E_APAT are not exact enough for this purpose, because a search via the MAPL results in two possible positions of the assigned SOBU (SOBU #m or SOBU # m + l). A search via the MAPL will require an additional search within the sequence. This is not possible in real time. But with the TE_S_OFF and TE_E_OFF the exact position of the SOBU can be located without an examination of the sequence. Rules for TE cells The information stored in the TE cells is defined so that * the original state of the program can be reconstructed at 100%, and * indicate the SOBUs completely covered by the TE part. This is required in order to be able to reuse on the fly during recording the complete SOBUs of TE parts, that is, without having to examine the sequence. This will be done by TE_S_OFF and TE_E_OFF of the C_TY. By means of these values, two sites are defined: 1. TE_S_S0BU = TE_S_0FF + (number of the SOBU, derived from the SC_S_APAT via the MAPL) 1. TE_E_SOBU = TE_E_OFF + (number of the SOBU, derived from the SC_E_APAT via the MAPL) . The "number of the SOBU derived from the SC_S_APAT via the MAPL route" is the number of that SOBU that contains the Application Package with APAT = SC_S_APAT or the previous SOBU based on the IAPAT of the resolution of the mapping list. Therefore, an exact location of TE_S_0FF and TE_E_0FF requires a test of the sequence. TE_S__0FF should be selected so that TE_S_S0BU satisfies the following conditions: 1. if SC_S_APAT is the first application pack of a SOBU or the TE cell contains the start of the SOB, then TE_S_SOBU is the SOBU number of that SOBU that contains the SOBU package. Application with the APAT SC_S_APAT. 2. in all other cases TE_S_S0BU is equal to the SOBU number of that SOBU that immediately follows the SOBU that contains the Application Package with the APAT SC__S_APAT. 3. TE_S_S0BU locates the SOBUs of an SOB in relation to its start, that is TE_S_S0BU = 1 locates the first SOBU of the SOB. TE_E_OFF must be selected so that TE_E_S0BU satisfies the following conditions: 1. TE E SOBU is equal to the SOBU number of that SOBU containing the application package that follows immediately after the TE cell. 2. TE_E_SOBU locates the SOBUs of an SOB in relation to its beginning, that is, TE_E_SOBU = 1 locates the first SOBU of an SOB. TE_E_SOBU may indicate the SOBU in case the last application pack of a SOBU is temporarily deleted after the last SOBU of the TE cell or the SOB. The 3 possible cases of TE_S_SOBU and TE_E_SOBU of a TE cell: 1) TE_S_SOBU < TE_E_SOBU There is at least one complete SOBU within the TE part of this TE cell. All complete SOBUs in this TE cell can be permanently erased, for example during recording. 2) TE_S_SOBU = TE_E__S0BU There is no complete SOBU inside the cell TEA. But the TE cell has Application Packages in 2 SOBUs. A permanent deletion will divide the assigned SOB between these two SOBUs into 2 SOBs. That is to say that the 2 Resulting SOBs do not share any SOBU. 3) TE_S_SOBU > TE_E_SOBU There is no complete SOBU inside the TE cell. The TE cell only has Application Packs in 1 SOBU. A permanent deletion will divide the assigned SOB into a SOBU in 2 SOBs. That is, the 2 SOBs share a common SOBU. Thus, each condition is unambiguous and contains a lot of information about the location of the cells within the sequence. Alternative solution C_TY can be described in another format as (1) C_TY describes the Cell Type of this Sequence Cell b7 b6 b5 b4 b3 b2 bl bO C TY1 reserved TE S OFF TE E OFF C TY1 .. 010b 'will be described for all sequence cells. TE S OFF? 00b ': This is a Normal Cell "(TE_E_OFF must also be 00b'.? 00b ', 01b', HOb ': The first TE SOBU starts the (TE_S_0FF-1) SOBUs later than the SOBU number calculated by SC_S_APAT via MAPL, TE E OFF? 00b ': This is a Normal Cell "(TE_S_0FF must also be * 00b'. 00b ',? 01b',? 10b ': The SOBU number of the first SOBU after the last TE SOBU of the TE cell initiates the (TE_E_0FF-1) SOBUs later than the SOBU number calculated by SC_E_APAT via the MAPL, in order to distinguish a normal cell from a temporarily deleted cell C_TY [3 ..0] == 0 when this is a normal cell, otherwise this is a TE cell, with this definition a TE cell is also unambiguously described, but bit 4 of C_TY is still free for other purposes.

Claims (1)

1. CLAIMS Method for marking data from a digital data stream that represents video or audio information that includes the following steps: in order to access exactly one Sequence Object Unit that can be completely deleted, the two values moved to one are added. cell-type flag, in which the first offset value is chosen, from which a Temporally Deleted Start Sequence Object Unit satisfies the conditions: if the Start Application Pack Arrival Time is the first Application Unit of an Object Unit Sequence or a Temporarily Deleted Cell contains the start of the Sequence Object, then The Object Unit Sequence of Temporally Deleted Sequence is the number of the Sequence Object Unit of that Sequence Object Unit that contains the Application Package with the Arrival Time of the Sequence. Start Application Package, in all other cases the Application Package Arrival Time Start is equal to the number of the Sequence Object Unit of that Sequence Object Unit that immediately follows the Sequence Object Unit that contains the Application Package with the Arrival Time of the Application Package Start, in which the second displaced value is chosen, from which a Sequence Unit starts Temporally Deleted satisfies the conditions: the Temporally Deleted Final Sequence Object Unit is equal to the number of the Object Unit Sequence of that Object Unit Sequence that contains the Application Package that follows immediately after the Temporarily Deleted Cell. Method according to claim 1, characterized in that the Temporally Deleted Start Sequence Object Unit accesses the Object Sequence Sequence Units Sequence in relation to its start. Method according to claim 1, characterized in that the Temporally Deleted Final Sequence Object Unit accesses the Object Sequence Sequence Units Sequence in relation to its start. Method according to claim 1, characterized in that the Temporally Deleted Start Sequence Object Unit is equal to the first displaced value + the number of the Sequence Object Unit, derived from the Arrival Time of the Start Application Package via a List of Mapping the End Sequence Object Unit Temporarily Erased is equal to the second displaced value + the Object Unit number 10 Sequence, derived from the Arrival Time of the Final Application Package via a Mapping List.