Encoding and Decoding Method, and Encoding and Decoding Devices with a Two-Stage Error Protection Process

Abstract

An encoding method for a series of data packets transmitted in the framework of a combined streaming and downloading application by a two-stage error protection process and only one unidirectional transmission channel. According to said method, a partial block of successive data packets is protected against at least some of the transmission errors occurring during streaming with the aid of a first error protection process while all data packets are protected against the transmission errors remaining after streaming is completed with the aid of a second error protection process. In a decoding method by which a series of data packets that are encoded according to the encoding method are decoded. Also disclosed is an encoding and decoding device for carrying out the method.

1 - 16 . (canceled) 
   
   
       17 . An encoding method for transmitting a series of data packets via at least one unidirectional transmission channel within the framework of a combined streaming and downloaded application using a 2-stage error protection process, comprising:
 dividing the series of data packets into partial blocks, each being formed from a plurality of successive data packets occurring during streaming with the aid of a first error protection process (FS1),   b) all data packets (D 1 , . . . , DN) are protected against transmission errors remaining after streaming is completed with the aid of a second error protection process (FS2) and the following steps are performed for transmission of a series of data packets:   c) several successive data packets (D 1 , . . . , DN) are combined in each case to form a partial block (T 1 , . . . , TM)];   forming an error protection block for each partial block with the aid of a first error protection process that protects against at least one type of transmission errors occurring during streaming, each error protection block being formed in such a way that:
 each data packet is encoded to form a corresponding error detection packet that represents the data packet; and 
 each error protection block includes at least one additional packet serving as a redundant block; 
   sequentially transmitting the error protection blocks in a time sequence corresponding to a playback order of the data packets represented by the error detection packets;   combining all error detection packets to form a complete block;   applying a second error protection process to the complete block to form a complete error protection block; and   transmitting the complete error protection block after all error protection blocks are transmitted.   
   
   
       18 . The method as claimed in  claim 17 , wherein
 at least one of the following error protection algorithms is used for the first and/or second error protection process:
 EXOR parity code; 
 Reed-Solomon code; and 
 Low density parity check code. 
   
   
   
       19 . The method as claimed in  claim 17 , wherein
 the quantity of error detection packets in the partial block is determined as a function of a specifiable delay, taking account of a transmission rate, a redundant block length and an error detection packet length.   
   
   
       20 . The method as claimed in  claim 17 , wherein
 a characteristic value is created for each data packet by a statistical method,   the characteristic value represents an importance of the respective data packet with respect to at least one other data packet,   the quantity of data packets for the partial block is selected in such a way that a sum of characteristic values of successive data packets within the respective partial block reaches at least one specifiable threshold.   
   
   
       21 . The method as claimed in  claim 17 , wherein
 the error protection block is created in such a way that within an error protection block the encoded data packets are provided with unequal error protection.   
   
   
       22 . The method as claimed in  claim 21 , wherein
 error detection data packets containing important information have more error protection, and   error detection data packets containing less important information have less error protection.   
   
   
       23 . The method as claimed  claim 17 , wherein
 the error protection block is created in such a way that a specifiable number of erroneous error detection packets can be corrected within the error protection block by the first error protection process.   
   
   
       24 . The method as claimed in  claim 17 , wherein
 at least one erroneous error detection packet within the error protection block can be corrected by the first error protection process.   
   
   
       25 . The method as claimed in  claim 17 , wherein
 at least two successive erroneous error detection packets within the error protection block can be corrected by the first error protection process.   
   
   
       26 . The method as claimed in  claim 17 , wherein
 the complete error protection block is created in such a way that a greater number of erroneous error detection data packets can be corrected with the second error protection process than with the first error protection process.   
   
   
       27 . The method as claimed in  claim 17 , wherein
 the complete error protection block is created in such a way that it has segments formed by reordering error detection packets, each segment being formed such that errors are separately corrected within the segment.   
   
   
       28 . The method as claimed in  claim 17 , wherein
 during the transmission of the error protection blocks, the error detection packets are transmitted via a first transmission channel and the redundant blocks are transmitted via a second transmission channel.   
   
   
       29 . The method as claimed in  claim 28 , wherein
 the error detection packets and the redundant blocks are transmitted in synchronization in such a way that the redundant block of the respective error protection block is present at a receiver not later than a time of reception of a last error detection packet of the respective error protection block.   
   
   
       30 . The method as claimed in  claim 18 , wherein the quantity of error detection packets in the partial block is determined as a function of a specifiable delay, taking account of a transmission rate, a redundant block length and an error detection packet length. 
   
   
       31 . The method as claimed in  claim 18 , wherein
 a characteristic value is created for each data packet by a statistical method,   the characteristic value represents an importance of the respective data packet with respect to at least one other data packet,   the quantity of data packets for the partial block is selected in such a way that a sum of characteristic values of successive data packets within the respective partial block reaches at least one specifiable threshold.   
   
   
       32 . The method as claimed in  claim 31 , wherein
 the error protection block is created in such a way that within an error protection block the encoded data packets are provided with unequal error protection.   
   
   
       33 . The method as claimed in  claim 32 , wherein
 error detection data packets containing important information have more error protection, and   error detection data packets containing less important information have less error protection.   
   
   
       34 . A decoding method comprising decoding a sequence of error detection packets encoded in accordance with the encoding method according to  claim 17 . 
   
   
       35 . An encoding device for a series of data packets transmitted via at least one unidirectional transmission channel within the framework of a combined streaming and downloaded application using a 2-stage error protection process, comprising:
 a division unit to divide a series of data packets into partial blocks, each being formed from a plurality of successive data packets;   a block forming unit to form an error protection block for each partial block with the aid of a first error protection process that protects against at least one type of transmission error occurring during streaming, each error protection block being formed in such a way that:
 each data packet is encoded to form a corresponding error detection packet that represents the data packet; and 
 each error protection block includes at least one additional packet serving as a redundant block; 
   a first transmission unit to sequentially transmit the error protection blocks in a time sequence corresponding to a playback order of the data packets represented by the error detection packets;   a combination unit to combine all error detection packets to form a complete block;   a correction unit to apply a second error protection process to the complete block to form a complete error protection block; and   a second transmission unit to transmit the complete error protection block after all error protection blocks are transmitted.   
   
   
       36 . A decoding device comprising a decoder to decode a sequence of error detection packets encoded according to the encoding method according to  claim 17 .