APPARATUS AND METHOD FOR RECORDING A DIGITAL INFORMATION SIGNAL WITH TRICK PLAY INFORMATION IN SLANT TRACKS ON A RECORD CARRIER

Abstract: A signal processing technique has been described for generating and processing trick play information for recording on a record carrier. First outer error correction coding ECC1(10) is carried out on N trick play sync blocks in memory MEM1 (8), to generate M trick play sync blocks of parity. MEM2 (20) receives sync blocks from MEM1 and normal play signal processing unit (5). Second outer error correction coding ECC2 (22) is applied on the P sync blocks of MEM2 to generate Q parity sync block. Then inner error correction coding ECC3 (24) is carried out. The order in which trick play sync blocks are supplied by first ECC to second ECC is different to order in which third ECC supplies trick play signal to writing means.

Description: APPARATUS AND METHOD FOR RECORDING A DIGITAL INFORMAΗON SIGNAL WITH TRICK PLAY INFOR ¬ MAΗON IN SLANT TRACKS ON A RECORD CARRIER The invention relates to an apparatus for recording a digital information signal in slant tracks on a record carrier, the apparatus comprising ■ input means for receiving the digital information signal, ■ first coding means for encoding the digital information signal so as to obtain sync blocks of information comprising a portion of information of the digital ' information signal, ■ trick play signal receiving means for receiving a trick play signal, ■ second coding means for encoding the trick play signal so as to obtain trick play sync blocks of information comprising a portion of the trick play signal, ■ first error correction encoding means for carrying out an error correction encoding step on N trick play sync blocks of the trick play signal so as to obtain M trick play sync blocks comprising parity information, ■ generation means for generating groups of P sync blocks, a group of P sync blocks comprising sync blocks of the digital information signal and at least some of the N+M trick play sync blocks, ■ second error correction encoding means for carrying out a second error correction encoding step on a group of P sync blocks so as to obtain a group of P+Q sync blocks, ■ third error correction encoding means for carrying out an error correction encoding step on each sync block in the group of P+Q sync blocks so as to obtain a group of P+Q error correction encoded sync blocks, writing means for writing P+Q error correction encoded sync blocks in a plurality of R tracks on the record carrier, where M, N, P, Q and R are integers larger than 1 and to a method. Such an apparatus is known from WO 98/34226. document Dl in the list of related documents. The document describes how a trick play signal has been derived, preferably from the video information signal received, where the video information signal are processed and combined into a composite information signal and recorded on the record carrier. The processing of the trick play signal and the video information signal into the composite signal requires an incorporation into a hardware solution, or a software solution, which is sometimes hard to realise. The invention aims at providing an improved apparatus, which makes the incorporation into a hardware or software solution better realisable In accordance with the invention, the apparatus is characterized in that the order in which the tπck play sync blocks are supplied by the first error correction encoding means to the second error correction encoding means is not the same as the order in which the third error correction encoding means supply the said tπck play sync blocks after error correction encoding to the wπtmg means The invention is based on the recognition that, by enabling a freedom in the order in which the tπck play sync blocks are supplied to the second error correction encoding means, this offers the engineer that has to provide an IC version of the signal processing possibilities to simplify the processing and/or make use of idle portions of the processing circuitry, so that a better and optimalized IC embodiment can be realised. These and other aspects of the invention will be descπbed hereafter in the figure descπption, in which figure 1 shows the apparatus in accordance with the invention, and figure 2 shows the signal processing in the first and second error correction encoding means earned out on the sync blocks. The apparatus compπses an input terminal 1 for receiving the input information signal, which may be an MPEG encoded video information signal, encoded into MPEG packets of information, with corresponding MPEG packets compπsing audio information corresponding to the said video signal. The input terminal 1 is coupled to an input 2 of a tπck play signal generation unit 3, as well as to an input 4 of a normal play signal processing unit 5 The tπck play signal generation unit 3 denves the tπck play signal from the incoming video information signal, e.g. such as descπbed in earlier filed EP patent application no 98201959 8, document D2 in the list of related documents This results in packets of MPEG encoded information of the tπck play signal, provided with a time stamp each, which packets are included in so-called trick play sync blocks (one packet in two subsequent trick play sync blocks) and supplied to an output 6. The normal play signal processing unit 5 processes the packets of the input information signal by adding time stamps to each of the packets and storing the packets in sync blocks again one packet in two subsequent sync blocks). The sync blocks for the input information signal and the trick play sync blocks for the trick play signal have the form as disclosed in document Dl, figure 10, however without the two sync bytes, the three ID bytes and the eight parity bytes shown in that figure, because they are added later to the sync blocks, as will be made clear below. It is assumed here that only one trick play signal, for only one trick play speed, is generated in the unit 3. It may, of course, be possible to generate more than one trick play signal, for other trick play speeds. It will be understood that, in such situation, the other one or more trick play signals will be processed in the same way. The output 6 of the trick play signal generation unit 3 is coupled to an input 7 of a memory unit 8, denoted MEM1. Each time, 102 trick play sync blocks of the trick play signal supplied by the unit 3 are stored in the memory unit 8. This is schematically shown in figure 2 by MEM1. A so-called 'vertical' or 'outer' error correction encoding ECC1 is carried out on the 102 trick play sync blocks of an individual trick play signal in the memory unit 8, so as to generate 10 trick play sync blocks of parity information. This is schematically shown in figure 1 by means of the processing unit 10, which realises the error correction encoding step ECC1 on the information stored in the memory 8, as well as by the 10 added trick play sync blocks comprising the parity information in the left hand side of figure 2. It should be noted that the block shown in the left hand side of figure 2 and denoted MEMl, is not actually the contents and the size of the memory unit 8, but more specifically gives an indication of the ECC1 processing on 102 trick play sync blocks. The actual size of the memory unit 8 will generally be equal to at least the amount of trick play sync blocks that should be stored in the trick play segments in the six tracks that form an ECC block of information. The output 12 of the unit 5 is coupled to an input 16 of a memory unit 14. Further, an output 18 of the memory unit 8 is coupled to an input 20 of the memory unit 14, also denoted MEM2. The memory unit 14 is capable of receiving so many sync blocks that 6 tracks on the record carrier can be filled with data. Those 6 tracks of information form an ECC block of information. From WO 98/23,226 (PHN 16614) it is known that one track comprises 336 sync blocks of information. Only 307 sync blocks, namely the sync blocks numbered 29 to 335 in each track in figure 1 of WO 98/34,226, are the sync blocks that will be discussed further. The memory unit 14 has sufficient memory space to store 6 x 307 = 1842 sync blocks of information. The memory unit 14 is filled with sync blocks of the incoming input information signal supplied by the unit 5 and with trick play sync blocks supplied by the memory unit 8. Actually, only 6 x 277 sync blocks from the units 5 and 8 are stored in the memory unit 14, for the reason that the last 30 sync blocks in each track, the sync blocks numbered 306 to 335, see figure 1 in WO 98/34,226, are sync blocks comprising parity information and will be derived in an error correction encoding step to be described later. The unit 5 supplies such amount of sync blocks of the normal play data to the memory unit 14 as required for recording in those 6 tracks that form the error correction block of information. More specifically, the unit 5 supplies sync blocks that will in the end be recorded in one of the sync block positions numbered 29 to 305, inclusive, in those 6 tracks, so long as such position is not restricted for the storage of the trick play data. The memory unit 8 supplies so many trick play sync blocks as needed to fill the trick play segments for the one or more trick play signals, that are present in the 6 track error correction block. This amount of trick play sync blocks can include the repetitions, all extensively described in WO 98/34,226. The contents of the memory unit 14 is schematically shown at the right hand side of figure 2. In fact, the memory unit 14 is filled with 6 x 277 sync blocks of 99 bytes long. Next, a second error correction encoding is carried out on the sync blocks in the memory unit 14. This second error correction encoding step is realised under the influence of the control block 22, denoted ECC2, in figure 1. The second error correction encoding step is again a so-called 'vertical' or 'outer' error correction encoding, carried out on the 6 x 277 sync blocks in the memory unit 14, so as to generate 6 x 30 sync blocks of parity information. Figure 2 shows those (6x30=) 180 parity sync blocks below the 6 x 277 sync blocks, and denoted ECC2. Those 6 x 30 parity sync blocks are the parity sync blocks recorded at the end of each of the tracks, numbered SB306 to SB335. Next, a third error correction encoding is carried out on the sync blocks in the memory unit 14. This third error correction encoding step is realised under the influence of the control block 24, denoted ECC3, in figure 1. The third error correction encoding step is a so-called 'horizontal' or 'inner' error correction encoding step, carried out on the 6 x 307 sync blocks in the memory unit 14, so as to generate 8 parity bytes in each of the sync blocks. Figure 2 shows those 8 parity bytes in each of the sync blocks by ECC3, coupled at the end of the bit array of the bits in all those sync blocks. Next the memory unit 14 is read out, sync block after sync block for recording in the tracks on the record carrier. First, the sync blocks are supplied to a unit 26, in which two sync bytes and three ID bytes are added to each sync block, resulting in the complete sync blocks as shown in figure 10 of WO 98/34226. Further, auxiliary information, for incorporation into the sync blocks numbered 0 to 23 in the aux area 8, see figure 1 of Dl, is added to the datastream, as well as various pre amble and post amble portions. Next, after having carried out a channel encoding step on the sequence of complete sync blocks, the information is recorded on the record carrier, where in each track, the last 30 sync blocks are parity sync blocks. The 112 trick play sync blocks shown in the left hand side of figure 2 can be read from the memory unit 8, such that the trick play sync blocks are read from the top to the bottom in MEM1 in figure 2, for storage in the memory unit 14. In the end, those 112 trick play sync blocks will be stored on the record carrier such that, during trick play reproduction at the velocity corresponding to that trick play signal, they will be read during one rotation of the head drum. Reference is made in that respect to Dl. This order of reading the trick play sync blocks from the memory unit 8 is however not a necessity. If this is convenient, because of processing reasons, to store the trick play sync blocks in another order in the memory unit 14, this is also possible, as long as the 112 trick play sync blocks discussed above will in the end be recorded in such trick play segments on the record carrier that they will be read during that same one rotation of the head drum in the trick play mode. For a reverse trick play speed, the trick play sync blocks should be read from the unit 8 in a reverse order, so that they will be recorded in a reverse order on the record carrier. Upon reproduction, the inverse processing can be carried out, resulting in a replica of the original signals: the normal play information signal during normal play reproduction mode and a trick play information signal during a trick play reproduction mode. Whilst the invention has been described with reference to preferred embodiments thereof, it is to be understood that these are not limitative examples. Thus, various modifications may become apparent to those skilled in the art, without departing from the scope of the invention, as defined by the claims. Further, the invention lies in each an every novel feature and combination of features. Related documents (Dl) WO 98/34226 (PHN 16.614, A Rijckaert) (D2) EP patent application no. 98201959.8 (PHN 16959, O. Eerenberg et al), filing date 11- 06-1998.

Claims: CLAIMS: 1. Apparatus for recording a digital information signal in slant tracks on a record carrier, the apparatus comprising ■ input means for receiving the digital information signal, ■ first coding means for encoding the digital information signal so as to obtain sync blocks of information comprising a portion of information of the digital information signal, ■ trick play signal receiving means for receiving a trick play signal, ■ second coding means for encoding the trick play signal so as to obtain trick play sync blocks of information comprising a poπion of the trick play signal, ■ first error correction encoding means for carrying out an error correction encoding step on N trick play sync blocks of the trick play signal so as to obtain M trick play sync blocks comprising parity information, ■ generation means for generating groups of P sync blocks, a group of P sync blocks comprising sync blocks of the digital information signal and at least some of the N+M trick play sync blocks, ■ second error correction encoding means for carrying out a second error correction encoding step on a group of P sync blocks so as to obtain a group of P+Q sync blocks, ■ third error correction encoding means for carrying out an error correction encoding step on each sync block in the group of P+Q sync blocks so as to obtain a group of P+Q error correction encoded sync blocks, ■ writing means for writing P+Q error correction encoded sync blocks in a plurality of R tracks on the record carrier, where M, N, P, Q and R are integers larger than 1, characterized in that the order in which the trick play sync blocks are supplied by the first error correction encoding means to the second error correction encoding means is not the same as the order in which the third error correction encoding means supply the said trick play sync blocks after error correction encoding to the writing means. 2. Method for recording the digital information signal in the slant tracks on a record carrier, in an apparatus as claimed in claim 1.

Inventors: RIJCKAERT ALBERT M A, STEENHOF FRITS A, RIJCKAERT, ALBERT, M., A., STEENHOF, FRITS, A.
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 1999
Main classification: G11B20
IPC codes: G11B20, G11B27, H03M7, H03M13, H04N5