DE10305657A1 - Method for the reconstruction of multimedia object data with digital audio broadcast (DAB receiver) - Google Patents

Abstract

A method for the reconstruction of multimedia object data with a digital audio broadcast (DAB) receiver, which are transmitted in the multimedia object transfer (MOT) protocol, wherein multimedia objects are transmitted segmented into data segments (SEG) and can be identified with a transport identifier (TransportID) in the data stream, and the data segments (K-SEG, R-SEG) for header data and for trunk data each have segment numbers (x) according to their sequence in the header or trunk part of the associated multimedia object , has the steps of storing the received data segments (SEG) in a data memory (8) in a memory area reserved for the multimedia object in a memory position which is selected depending on the segment number (x) and the data segment size (n) such that the data segments (SEG) of the header or body part of a multimedia object in the order of the segment numbers (x) consecutively in the Storage area.

Description

The invention relates to a method for the reconstruction of multimedia object data with a digital audio broadcast (DAB) receiver, which are transmitted in the multimedia object transfer (MOT) protocol are transferred, multimedia objects segmented into data segments and can be identified with a transport identifier in the data stream, and wherein the data segments for Header data and for Body data each segment number according to their order in the head part or trunk part of the associated multimedia object.

The invention further relates to a digital audio broadcast (DAB) receiver with a reconstruction unit for decoding multimedia object data, which are transmitted in the multimedia object transfer (MOT) protocol are transmitted segmented by multimedia objects in data segments become identifiable and with a transport identifier in the data stream and where the data segments are for header data and for body data each segment number according to their order in the header or body part of the associated Multimedia object to have.

With the European standard EN 300 401 “Radio Broadcasting systems; Digital Audio Broadcasting (DAB) to mobile, portable and fixed receivers " a method for broadband transmission digital audio data set. Together with the audio data, too Multimedia data are also transmitted in the transport data stream. This is the european Standard EN 301 234 "Digital Audio Broadcasting (DAB), Multimedia Object Transfer (MOT) protocol ". The multimedia object data can be any Have formats and forms, such as texts, images, videos etc.

The multimedia object data will be here in the so-called Program Associated Data (PAD) or in so-called packet mode of a DAB data stream. So in a DAB receiver a MOT decoder called reconstruction unit at the output of the PAD decoder and / or packet mode decoder optionally provided.

The multimedia object transfer (MOT) protocol stipulates that multimedia objects, hereinafter referred to as MOT objects, consisting of a 7-byte header core part, a head extension part and a trunk part. The head-core part contains information about the size and the Content of the object so that the DAB receiver can determine whether sufficient Resources for decoding and presenting the MOT object available. The header extension contains information to support the Handling the object, e.g. Storage instructions. The fuselage part contains the actual data of the multimedia object to be transmitted.

For transferring a MOT object it is divided into at least a head segment and a trunk segment. Each segment is in turn segmented into at least one data group. The Data groups then become independent integrated into the transport data stream and unique or sent out repeatedly. The sending of the data groups can for example in a so-called data carousel by for example, the data groups of a MOT object first in succession be broadcast. This procedure is then repeated several times. It is also conceivable that initially a data group is broadcast several times and then the The following data group of the MOT object was again broadcast several times until all Transfer data groups of the MOT object are.

For the transfer the data groups are built into so-called main service channel (MSC) data groups, in which a transport identifier (TransportID) for identification the associated Multimedia object is present in the so-called "session header". In the data group header also contains the type of data segments. Type 3 stands for Head segments and types 4 and 5 for body segments.

The data segments also have a segment header, in which i.a. the segment size noted is. Each segment of a header segment also has a consecutive segment number. The segment numbers are for the header data segments and the trunk data segments of a MOT object each counted separately. The Segment number is in the “Session Header "of an MSC data group recorded.

In the head-core part of a MOT object is still the total size of the headboard as well as the overall size of the fuselage part recorded.

The data segments of a header or Part of the fuselage of a MOT object are divided so that they have a constant segment size. Only the last segment of a head part or trunk part can be one of them have different segment size. This depends from the remaining data bytes of the segment. The last data segment is therefore not filled with empty information.

The maximum size of a data segment is 8 kilobytes.

Conventionally, when receiving MOT objects, the wait is first until a header data segment of a MOT object has been received. After the head part has been completely received and stored in a working memory, it is decoded. Then the data segments forming the fuselage part of the associated MOT object are collected in the working memory. The MOT object is only decoded when all data segments of the fuselage part have been received and stored overall in a data memory. The MOT object stored in this way can then be further processed and displayed.

This process of reconstruction of multimedia object data disadvantageous to a time delay because initially on the reception of the head part of the MOT object must be waited for. In addition, the DAB receiver fitfully burdened because after receipt of all data belonging to a MOT object this is moved from the main memory to another storage medium must become.

Through the longer process of saving of a MOT object can receive subsequent header data segments failed become. This may result a loss of time.

The object of the invention is therefore an improved generic method for the reconstruction of multimedia object data as well as an improved Digital audio broadcast receiver too create so that in particular a reduction and more efficient System resources can be used is.

The task is accomplished with the generic method solved according to the invention by Storage of the receiving data segments in a data memory in one for the storage area reserved for the multimedia object in a storage position, the dependent is selected from the segment number and the data segment size in such a way that the data segments of the head part or trunk part of a multimedia object in consecutive order of the segment numbers be stored in the memory area.

The information is thus according to the invention of the received data segments used to the expected size of the associated MOT object and the position of the current data segment within the MOT object to calculate. Then the required one Storage space in the data storage can be used immediately without temporary storage in a working memory is necessary. The data segments are thus immediately in one for the MOT object memory area to be reserved according to your order in the MOT object collected. Once a MOT object is fully received and in the data store stored, it can then be decoded.

A data segment is then sent to the Beginning of for the associated Head or trunk part of the multimedia object provided storage area filed if the header or body part is a single data segment having.

Especially for the special case that a to be saved Data segment the last data segment of the associated header or body part of the MOT object, the storage position becomes dependent from the segment size before received and stored data segments of the associated header or body part of the multimedia object selected. This is necessary because the data segment size of the last one Data segments from the otherwise constant data segment size of the previous one Data segments of the associated Possibly head or torso can distinguish.

If no previous data segments the associated Head or torso have been received, a received last Discarded data segment. This is necessary because of the storage location lack of knowledge of the constant data segment sizes of the previous data segments cannot be calculated.

The storage position should be within the for that associated Multimedia object reserved memory area proportional to the product of segment number and segment size can be selected. this makes possible a linear memory addressing of the respective memory area.

It is also advantageous if the segment numbers of the received data segments of a header or Fuselage part of a multimedia object are listed. Then it will be uses the segment number in the list to check whether a data segment already exists was received to be transmitted multiple times Data segments not taken into account allow.

The complete reception of a multimedia object can be checked by the data segment sizes for the header and the fuselage part of a multimedia object are added up. The The sum determined is then the one specified in the header data Size of the multimedia object compared.

The task is also carried out by the Generic digital audio broadcast receiver solved by a reconstruction unit for performing the above Procedure is formed. This can be done, for example, by firm wired integrated circuits or preferably through software programming respectively.

The invention is described below the attached Drawings closer explained. Show it:

1 - Block diagram of a DAB receiver with MOT decoder;

2 - Schematic representation of the division of multimedia object data into a MOT object, in data segments and in data groups;

3 - Schematic representation of the positioning of the received data segments in the data memory.

The 1 leaves the block diagram of a digital audio broadcast receiver according to the Recognize the definition of the DAB standard ETS-EN 300 401. The DAB receiver has a high frequency part 1 with a subsequent signal processing unit 2 for signal decoding with a Fast Fourier Transform FFT, with a demultiplexing method and with a channel decoding. The audio data stream is in an audio decoder 3 decoded and with speakers 4 played.

There is also a PAD decoder 5 for decoding the program-associated data PAD and a packet decoder 6 intended for packet decoding. At the output of the PAD decoder 5 as well as the packet mode decoder 6 then data segments are available according to the definition of the DAB standard, which are in a multimedia object transfer decoder 7 be directed. At least this so-called MOT decoder 7 is with a data store 8th coupled to save the data of the transmitted multimedia objects. The multimedia object data MOD and possibly additional information are transmitted via a further data processing unit 9 or suitable software for playback.

The multimedia object data MOD are transmitted in segments according to the multimedia object transfer protocol. This is shown schematically in the 2 shown. The multimedia object data MOD are divided into body data segments in the body part of a MOT object. A MOT object also has a header core part and, if appropriate, a header extension part in accordance with the definition of the DAB-MOT standard ETS-EN 301 234. The header part is in turn divided into data segments K-SEG, each of which contains a segment header SK and a segment data part Have SD. Among other things, the segment size is recorded in the segment header.

The fuselage data segments R-SEG are also in corresponding data segments with segment head SK and segment data part Transfer SD.

The data segments SEG are in data segments with a DGH (Data Group Header), a so-called Session header SH, a data group data field DG (Data Group Data Field) and optionally a so-called MSC-Data Group CRC. The Data Group Header DGH contains the type of data segments SEG. So the number 3 denotes a head part and the numbers 4 and 5 a body part.

Furthermore is in the session header SH there is a transport identifier (TransportID) that contains the associated MOT object designated. The data segments SEG can thus be identified in relation to the MOT object.

The individual data segments or Data groups are independent of each other in the transport stream if necessary, transmitted several times in succession.

To reconstruct the data of a MOT object, the segment number of a received data segment SEG is now evaluated according to the invention, and as in FIG 3 outlines the received data segment SEG in the data memory 8th stored in a memory area reserved for the MOT object in the correct order of the data segments. The storage position is selected depending on the segment number x and the data segment size n such that the data segments K-SEG, R-SEG of the head part or trunk part of a MOT object are consecutively in succession in the memory area of the MOT object in the numerical order of the segment numbers x be filed.

When the segment x = 2 is received first was, this is due to the known length n of the MOT object at one Storage position proportional to the product of the segment number x = 2 and the constant data segment size n filed. Because the data segments also include information as to whether it is the last data segment a MOT object acts, the data segment size n des current data segment SEG to calculate the storage position be used. If, however, it is the one to be saved Data segment SEG around the last data segment SEG of the MOT object acts, would then the constant data segment size n to calculate the storage position previous data segments SEG can be used. This is why it has to occur because the last data segment SEG may be a smaller one Data segment size has m ≤ n, than the constant data segment sizes n the previous data segments SEG.

The data segment SEG with the segment number 1 is then received and accordingly in front of the data segment SEG with the segment number 2 in the data memory 8th stored. Then the data segment SEG with the segment number 0 is received and before the data segment SEG with the segment number 1 in the data memory 8th stored. Finally, the data segment is SEG with the segment number 3 received and directly behind the last data segment SEG with segment number 2 in the data memory 8th stored. The storage position for the last data segment SEG with the segment number 3 can, as described above, take place by using the constant data segment size n of the previous data segments.

Claims (8)

Method for the reconstruction of multimedia object data (MOD) with a digital audio broadcast (DAB) receiver, which are transmitted in the multimedia object transfer (MOT) protocol, wherein multimedia objects are segmented into data segments (SEG) are transmitted and can be identified with a transport identifier (TransportID) in the data stream, and the data segments (K-SEG, R-SEG) for header data and for trunk data each have segment numbers (x) according to their sequence in the header or trunk part of the associated multimedia object, characterized by storing the received data segments (SEG) in a data memory ( 8th ), in a memory area reserved for the multimedia object in a memory position that is selected depending on the segment number (x) and the data segment size (n) such that the data segments (K-SEG, R-SEG) of the header or body part of a Multimedia objects are successively stored in the memory area in the order of the segment numbers (x). A method according to claim 1, characterized in that a data segment (SEG) at the beginning of that for the associated head or body part of the multimedia object provided storage area is stored when the header or Body part has a single data segment. A method according to claim 1, characterized in that the storage location depending on the segment size before received and stored data segments (SEG) of the associated header or body part of the multimedia object is selected, in particular if the data segment to be saved (SEG) the last data segment (SEG) the associated Head or torso part. A method according to claim 3, characterized by discarding a received last data segment (SEG) if no previous ones Data segments (SEG) of the associated Head or torso were received. Method according to one of the preceding claims, characterized characterized that the storage position within the storage area for a multimedia object proportional to the product of segment number (x) and data segment size (n) is selected. Method according to one of the preceding claims, characterized by listing the segment numbers (x) of the received data segments (SEG) of a head or body part of a multimedia object, checking based on the segment number (x) in the listing whether a data segment (SEG) already exists was received, and ignoring a multiple transmitted data segment (SEG). Method according to one of the preceding claims, characterized by checking the complete receipt of a multimedia object by adding up the data segment sizes for the header and body parts of a multimedia object and comparison the sum determined, with the size of the multimedia object specified in the data of the header. Digital audio broadcast (DAB) receiver with one Reconstruction unit for decoding multimedia object data (MOD) transmitted in the multimedia object transfer (MOT) protocol are transmitted segmented in the multimedia object into data segments (SEG) become identifiable and with a transport identifier (TransportID) in the data stream are, and by the data segments (K-SEG, R-SEG) for header data and for Body data segment numbers (x) according to their order in the head part or trunk part of the associated multimedia object, characterized in that the reconstruction unit for performing the Method according to one of the preceding claims is formed.