MXPA01002745A - Method of and device for recording information - Google Patents

Abstract

A method is described for writing real time video signals on an optical disc (2) having a recording area (40) which comprises an administrative area (43), a spare area (42), and a user area (41). Normal recording takes place in blocks (45) in a first pre-reserved area (NW) of a free part (47) of the user area (41). If during the recording process a defective block (45*) is encountered a replacement recording having the size of a plurality of blocks is made in a second pre-reserved area (RW) of the free part (47) of the user area (41), after which normal recording continues in the first pre-reserved area (NW). On the one hand, this limits the number of jumps for replacement recording and, on the other hand, it results in the storage capacity of the disc (2) being used very efficiently.

Description

Method and device to record information In general, the present invention relates to the recording of information, particularly digital information, in a disc-shaped recording medium, such as an optical disc or a magnetic disc, hereinafter referred to as a "recording disc". As is already known, said recording disc has a multitude of substantially circular concentric recording readings. Said recording readings may take the form of individual circular readings or a continuous spiral reading. Each reading is divided into logical blocks and each block has a data area for recording data. In addition, usually each block has an area reserved for recording a verification number or "checksum". In general, the amount of information that will be recorded in a recording session is greater than a block. The information that will be recorded, also referred to as "file", is then divided into successive packets of data that are the size of a block and the successive packets of data of a file are recorded in different blocks of the disk. Then, for a fast transfer of data, it is desired that the successive packets of data be recorded in successive blocks. Then, the process can proceed in a continuous and virtual way. In the same way, the reading process can proceed continuously during the subsequent reading (reproduction) of the information recorded on the disc. In practice, a disk may show defective blocks, for example, blocks where an impeccable recording of information may no longer be possible or where a small writing error resulting during reading can no longer be corrected. Then, said block is no longer its own for recording. It is customary to reserve a spare area on the recording disc, the user can not be directed to that area as it is designed for the replacement of any defective block. When a defective block is found during recording, recording is performed in a block of the area Replacement recording instead of the defective block. After recording a data packet in a block of the spare recording area, the recording of the following data packets in a block following the defective block is continued. Therefore, said replacement requires two jumps of the recording head and, in the same way, two jumps of the reading head are required to read the information. These jumps of the read or write head from the normal recording area to the spare recording area and back are comparatively long and reduce the average speed of information transmission. This is particularly undesirable in situations where a very high transmission speed is required, as for example in a real-time recording of audio and / or video signals. For such uses, it is proposed not to make the breaks for the recording and return spare area for each damaged individual block, but to make them when a defective block is found to record a part of a file comprising a plurality of blocks in the spare area. Now, the jumps do not happen directly after another one in time, but the time between them is longer. The transmission speed averaged over a time interval that does not include both jumps is higher. However, one consequence is that the recording spare area fills up quickly, since a substantial number of data packets recorded in the recording spare area incorrectly occupy space in the recording spare area because the blocks that correspond to these data packets in the normal recording area are not defective. In this way, attention is paid to a reduction in the number of jumps due to a comparatively poor use of the recording spare area and the recording spare area fills up more quickly. Once the recording spare area is full, you can no longer use the disc to record more. Conversely, this means that the number of parts of the file for which the replacement recording was made in the spare area is comparatively small. It is an object of the present invention to provide a solution for the aforementioned solutions. According to an important aspect of the present invention, the replacement recording is carried out in a free recording, for example, an area that is freely accessible and to which it can be directed that has not yet been used. This area is large enough to record parts of a file that are hundreds of blocks in length. Before recording, the distribution manager reserves a certain part of the free recording area as a replacement area. This reservation implies, on the one hand, that the distribution administrator will not use the addresses in this reserved part of the free recording area to record. In case a defective block is found during recording, the writing head jumps to an appropriate address in the reserved area of replacement of the free recording area, for example, to the first free address in the replacement zone when the Carrying out a replacement recording in said replacement zone. After recording the part of a file in this replacement zone, the writing head returns to the normal recording area. At the end of the recording session, the distribution administrator is informed which addresses have been used in the replacement zone and which replacement addresses correspond to the original addresses. Then, the distribution administrator knows which addresses of the free area are no longer free and which addresses from which they were originally distributed have not been used and, therefore and in effect, are free.

Optionally, it is likely that this information has already been transferred to the distribution administrator during the recording session as a result of which, if necessary, the distribution administrator can reserve additional space in the normally accessible space during the session. recording process, for example when a very large number of errors occur. These and other aspects, features and advantages of the present invention will be clarified below by means of the following description of a preferred embodiment of the invention with reference to the drawings, in which: Figure 1 is a block diagram showing a part of the recording apparatus; Figure 2 shows in a diagram the logical structure of a recording disc in order to illustrate a conventional method of recording; and Figure 3 shows in a diagram the logical structure of a recording disc for the purpose of illustrating a recording method according to the present invention. Figure 1 shows a block diagram of a part of a recording apparatus 1 suitable to record video or audio signals S in real time on a recording disc 2. It will be evident to a person skilled in the art that the purpose of this invention is not limited to the examples described above, but it is possible to make various changes and modifications thereto without departing from the scope of the invention, as defined in the appended claims. For example, the present invention can already be exploited if only predetermined test readings are examined in the test procedure, even if the test procedure is not based on the use of the reading signal, although it is preferred. The disk 2 can be a magnetic disk, but the present invention is designed for optical recording in particular. The disk 2 has a multitude of mutually concentric recording readings 3, which are assumed to be individual circular readings hereinafter, but it is possible that the readings 3 represent a continuous spiral reading. As it is known as such, the apparatus 1 has an optical read / write head 10 and a disc plate, which is not shown for simplicity and which is facing the head 10, the disc 2 can be placed in said disc plate and by means of it a rotary movement can be given to the disc 2 relative to the head 10, thus allowing the head 10 to examine a reading 3. The recording apparatus 1 includes means, which are known as such and that are not shown for simplicity, to move the head 10 in a radial direction of the disc 2, thus allowing the head 10 to access different readings 3 of the disc 2. As is well known, the information is written in the reading 3 by means of a laser beam 11 from the head 10. The writing process is controlled by a functional unit 20, referred to hereinafter as the writing control unit. Said write control unit 20 is known as such and, therefore, is not described further. It should be noted that the writing control unit 20 is adapted to control the positioning of the head 10 with respect to the disk 2 in such a way that the writing process takes place at the desired location on the disk 2 through the control of the disk platter of said disk and said positioning means for the head 10. In addition, the writing control unit 20 controls the intensity of the laser beam 11 in dependence on the input signal S to be recorded. This control function of the writing control unit 20 is represented by a diagram like the coupling 22 in Figure 1. The recording apparatus 1 further has a functional unit 30, which is given the term distribution administrator from now on. Said distribution manager 30 is known as such and therefore is not described further. It should be noted that the distribution manager 30 is adapted to determine in which part of the disk 2 a certain recording session or a recording only takes place. When a user starts a recording, the distribution manager 30 determines if there is enough space to record on the relevant disk 2 and, if this is the case, if said space is available. The distribution manager 30 informs the writing control unit 20 of the starting location of this available space, which is represented by a diagram as the coupling of signals 31. Figure 2 represents with a diagram the logical structure of the disk 2. The recording readings 3 together define a recording area 40 of the disc 2, which is shown as a continuous strip and which will also be referred to as the recording area hereinafter. The recording area 40 of the disk 2 has been divided into logical blocks 45, which have a previously determined individual address. The value of the relevant address of a block 45 has been recorded in a previously determined field for addresses of block 45. In this way, it is possible to record information directly in a certain location corresponding to a certain address on disk 2 and it is also possible to read the information directly from a given location that corresponds to a given address. Blocks 45 have a block size that does not need to be the same for all blocks. The amount of data that can be written to a block is called a data package. The recording area 40 consists of a substantial part of a space called airship 41, to which a user can access in order to record information, in the present example are the digitized video signals. This steerable space 41 will also be referred to as the user area hereafter. The recording area 40 of the disc 2 also includes a spare area 42, which is not steerable and which is used as a replacement area. The relative storage capacities of the user area 41 and the spare area 42 are not shown to scale in Figure 2: in general, the size of the spare area 42 is only one percent of the size of the user area 41.

The disk 2 also has a previously determined area 43 that stores information related to the content of the disk. It is likely that this information relates, for example, to the number of files on disk 2, the starting addresses of the files, the lengths of the files, the names of the files, etc. Reference will also be made to this area as the administrative area from now on. In Figure 2, the files carry the references f 1, f2, f3, etc. In general, the files occupy a plurality of blocks 45 for a file to comprise a plurality of data packets. Reference will be made to the part of the user area 41 that has already been used to store files such as the user occupied area 46 or occupied space. The unused portion of the user area 41 is still free: this part will be referred to as the free user area or free space 47 hereinafter. The blocks that a file uses must not necessarily be directly adjacent to each other in the steerable area 41. It is likely that the file comprises a plurality of snts, each of which may comprise a plurality of blocks whose snts are It can spread within the steerable area 41. Therefore, the free space consists of a plurality of snts with blocks that are not yet used. These addresses are kept in administrative space 43. For simplicity, the files are represented as a simple and continuous area. When the disk 2 is loaded to the recording apparatus, the distribution administrator 30 instructs the writing control unit 20, via the link 31, to read the administrative area 43 and transfer the information that, in this way, it reads to the distribution manager 30 by means of the coupling 31. The distribution manager 30 stores the information read in an associated memory 32. Now, the distribution administrator 30 knows which part of the user area 41 of the disk 2 is occupied by previous recordings of files f1, f2, etc. and, consequently, it is an area of • - ~ - * "• '" •' - user occupied 46 or occupied space. As a consequence, the distribution manager 30 also knows which part of the user area 41 is still free and, consequently, is a free user area or free space 47. When the distribution manager 30 receives a new write command , the distribution manager 30 checks in the associated memory 32 which part of the user area 41 is a free space and sends a start address and a terminating address in this free space to a write control unit 20 by means of the communication line 31. Distribution manager 30 also stores this data in memory 32 as an indication that the part of user area 41 defined by said start and end addresses no longer belongs to the free user area 47, but it does to the occupied user area 46. The write control unit 20 controls the recording process for the incoming signal S to be recorded, which is recorded or in the usual way, starting at that starting address received from the distribution manager 30. When the recording process has been completed, the unit of. writing control 20 reports it to the distribution administrator via communication line 31, after which, distribution administrator 30 instructs writing control unit 20 to update the data in administrative area 43 of the disk 2. It is likely that user area 41 contains defective blocks45 *. Then, it is possible that the distribution manager 30 does not know of the presence of certain defective blocks 45 * previously, and as a result of which said defective blocks 45 * are normally used for distribution. However, it is also possible that before the recording, the distribution administrator 30 knows which blocks can not be used as a result of the presence of defects. In the conventional way, these 45 * blocks are still used for distribution. It is assumed that the write control unit selects an alternative location by itself. If during the writing process the writing head 10 reaches a defective block 45 *, then the writing control unit 20 must move the writing head 10 to an alternative block and the data packet that should have been written in the defective block 45 * relevant is recorded in said alternative block. After recording the data packet in the alternative block, the write control unit 20 directs the write head 10 back to the user area 41 in the conventional manner. Reference is also made to said alternative block as a replacement block 45 'and to the recording of the data packet in a replacement block 45' as a replacement recording. Conventionally, an alternative block 45 'is selected in the replacement area 42. Due to the reciprocating movement of the writing head 10 a lot of time is lost and as a result of that, said conventional writing process is not very suitable for the processing of video signals in real time. The present invention proposes to reduce the number of jumps of the writing head 10 and increase the time between successive jumps when, when a writing head 10 reaches a defective block 45 'and, consequently, it is necessary to jump to a replacement block 45 ', the replacement recording is carried out not only for the data package to be written in the defective block, but also in that before jumping back it is written in replacement blocks 45 * a very large number of subsequent data packets. In this way, the subsequent data packets written in the replacement blocks 45 'can be 100 or more. In fact, there are usually errors in packet groups. By taking a large number of data packets, the number of hops is reduced. Reference is also made to said sequence of successive data packets written in replacement blocks 45 'as a part of the file.

The previously reserved reservation area 42 is comparatively small. In particular, this spare area 42 has been designed for an approximate capacity of 3% of the overall disc capacity, thus providing an alternate writing ability for all defective blocks 45 * in case no more than 3% of the blocks are defective. In the conventional writing process this is broadly sufficient in practice, because in that case only a replacement block 45 'is used for each defective block 45 * in the user area 41. However, if the parts of the file are written having a size of 100 or more data packets in the spare area 42 at the same time, it is inevitable that also a large number of replacement blocks 45 'of the spare area 42 are required as an alternative recording area for non-blocking blocks. defective 45 of the user area 41. This means that the spare area 42 fills up quickly and is likely to be already full even when the number of defective blocks 45 * in the user area 41 is much lower than i 3%. When the spare area 42 is full, disk 2 can no longer be used for recording. The present invention also provides a solution to this problem. For this purpose, according to the present invention, the distribution manager 30 is adapted to reserve two different areas in the user-free area for recording, a first area reserved for a normal recording and a second area reserved for a replacement recording . The distribution manager 30 informs the writing control unit 20 about these areas. The writing control unit 20 is adapted to carry out a normal recording in the first area and, when defective blocks 45 * are found, to carry out a replacement recording for the part of a file in the second area. As illustrated in Figure 3, the distribution manager 30 can, for this purpose, be adapted to specify a write start address WSA and a write end address WEA in the free user area 47, said addresses reserve a NW area for a normal recording, and also for specifying a replacement start address RSA and a replacement term address REA in the free user area 47, said addresses reserve an RW area for a replacement recording. Figure 3 shows that the NW area reserved for a normal recording is located at the beginning of the user free area 47 and that the RW area reserved for a replacement recording is located at the end of the user free area 47. In reality, the area Free user will understand a plurality of areas that are not together, but scattered throughout the dirigible space. Thus, it is also possible that the RW area reserved for a replacement recording will join the NW area reserved for a normal recording. The distribution manager 30 is adapted to communicate these addresses with the write control unit 20, which in turn is adapted to ensure that the recording of the information flow in the NW area reserved for normal recording within the free area of user 47 proceed in a conventional manner. However, the writing control unit 20 is adapted to ensure that, when a defective sector 45 * is found, the writing head 10 jumps to a place in the replacement zone RW within the free user area 47 for the purpose performing the replacement recording of the part of a file at said location and, subsequently, causing the writing head 10 to jump back to the reserved NW area for a normal recording within the free user area 47. It will be it is evident that in this way the replacement recording is carried out without the problems described above. In this way, the particular spare area 42 is not used. As is customary, the write control unit 20 reports to the distribution manager 30 when the recording process is finished and at that time the distribution administrator 30 instructs the write control unit 20 to update the data in the administrative area 43 of the disk 2. The distribution administrator 30 adds the addresses in the RW area reserved for replacement recordings to that administrative data in the administrative area 43. The addresses not used with the defects are left in the free user area. It is possible to add these addresses to the list of untrusted addresses. During a subsequent recording, the distribution administrator 30 can then define not to use these addresses for distribution. This prevents a loss of time during redistribution. In this way, the occupied space 46 of the user area 41 now comprises a pare 46W occupied by a normal recording, the blocks already used in the NW area and the blocks already used in the RW area. The distribution manager 30 writes this in the memory 32 and, at the time of termination of the recording session, records the information in the index in the administrative area 43 on the disk. When the disk 2 is loaded in the apparatus 1 on another occasion, a similar process is carried out: the distribution administrator 30 recognizes the addresses that have been used. From this information you can derive what free user area remains. A portion of this area is reserved for a replacement recording. It does not need to be the same part that was used during a previous recording. Typically, the size of the replacement zone RW in the user-free area 47 is larger than the size of the replacement area 42 and large enough to handle the number of replacement recordings that occur under normal conditions. If during the recording the user free residual space becomes small because the disk is filling, when there is still room in the replacement space, the distribution administrator 30 can reduce the replacement space by reporting it to the control unit of writing 20. In this way, you can use the entire disk to store. It is possible that during the recording session the writing control unit 20 also provides information to the distribution manager 30 about the size of the unused residual portion of the replacement RW area, as a result of which, if the number of recordings As the replacement is comparatively large and the replacement zone is, therefore, about to be filled even before the recording session is over, the distribution manager 30 can extend the replacement zone RW. Once the distribution administrator has reserved a part of the user-free area 47, the administrator will no longer consider this part as available for a normal recording. The method proposed by the present invention has some important advantages. During the recording session or the recording process you can dynamically change the size of the replacement area in the free space. This does not result in any loss of playing time as a result of the reserved replacement area. Theoretically, the disk can be used when almost 100% of the storage space is defective, but the residual time of reproduction decreases as there is more defective storage space and more replacement space is required (graceful degradation). This is contrary to the conventional method, where a disc can no longer be used when more than 3% defects occur. In this way and in summary, the present invention provides in particular a method for recording real-time video signals on a DVR disc having a recording area 40 which includes an administrative area 43, a spare area 42 and a recording area. user 41. Normal recording is performed in blocks 45 in a previously reserved first zone NW of a free part 47 of the user area. If a defective block 45 * is found during the recording process, a replacement recording of a part of a file having the size of a plurality of characters is made in a second reserved area RW of the free part 47 of the user area. blocks, after said recording continues with the normal recording in the first zone previously reserved NW. On the one hand, this reduces the number of jumps and limits the number of jumps that occur within a short period of time for the purpose of the replacement recording and, on the other hand, the storage capacity of the device is highly efficient. disk. It will be apparent to a person skilled in the art that the object of the present invention is not limited to the examples described above, but that different changes and modifications are possible without departing from the object of the invention, as defined in the appended claims. .

Claims (9)

CHAPTER CLAIMEDICATORÍO Having described the invention, it is considered as a novelty and, therefore, the content is claimed in the following: CLAIMS:

1. A method for recording information, particularly video or audio in real time, on a recording disc (2) of the type having a multitude of substantially concentric concentric recording readings (3) divided into blocks (45), particularly an optical disc, whose recording readings (3) as a whole define a recording area (40) of the disk (2), whose recording area (40) includes at least one user area that is freely accessible and steerable (41); wherein the information to be recorded is divided into data packets having the size of a block, wherein the successive data packets are recorded in different blocks (45) of said user area (41); and wherein, if a block (45 *) appears to be defective, a replacement recording is made for the relevant data packet in another part of said user area (41).

2. A method, as claimed in Claim 1, wherein before the recording session, a given part (RW) of said freely accessible and steerable user area (41) is reserved as a replacement zone.

3. A method, as claimed in Claim 2, wherein during the recording session, an extra portion of said freely accessible and steerable user area (41) is reserved as a replacement zone, if necessary .

4. A method, as claimed in any of Claims 1 - 3, wherein during the recording session the reservation of a part of the previously reserved replacement zone is canceled, in case it is necessary, in order to make said part available again as a free user area (47).

5. A method, as claimed in any of Claims 1-4, wherein if a defective block (45 *) is encountered during the recording process, a replacement recording is made for the part of a file comprising a plurality of successive packets of data.

6. A recording apparatus (1) adapted to carry out a method as claimed in any of Claims 1-5.

7. An apparatus for recording, as claimed in Claim 6, comprising: a writing control unit (20) adapted to control the writing process and a distribution manager (30) adapted to determine in which part of a disk (1) will perform a write operation; wherein the distribution manager (30) is adapted to reserve two different areas to record in a free part (47) of the user area a first area (NW) reserved for a normal recording and a second area (RW) reserved for a replacement recording; the distribution manager is adapted to inform the writing control unit (20) about these reserved areas (2); the writing control unit (20) is adapted to carry out the normal recording in the first previously defined area (NW) and, in case there are defective blocks (45 *), the time interval carries out a replacement recording for the part of a file having the size of a plurality of blocks in the previously defined second area (RW) and, at the time of completion of the replacement recording, proceeding with normal recording in the first area previously defined (NW).

8. An apparatus for recording, as claimed in Claim 7, wherein the writing control unit (20) is adapted to inform the distribution manager (20), at the time the recording process ends, the addresses used in the second previously defined area (RW), and wherein the distribution administrator (30) is adapted to put said addresses used in the second previously defined area (RW) into a memory (32) related to the distribution administrator (30). ) and in an index in the administrative area (43) of the recording area (40) of the disc (1).

9. An apparatus for recording, as claimed in Claims 7 or 8, wherein the distribution manager (30) is adapted to include the addresses of the defective block (45 *) resulting in the replacement recording in a list of Unreliable blocks and to inhibit the use of blocks included in said list for distribution when said two areas (NW; RW) are reserved to the command of the subsequent recording.