Abstract: A method of supporting synchronization of Scalable Video Coding (SVC) information and Advanced Audio Coding (AAC) information using a Normal Play Time (NPT), the method including: receiving video information using a decoding apparatus; receiving audio information using the decoding apparatus; calculating the NPT of the video information using a Real-time Transport Protocol (RTP) time stamp included in the received video information; calculating the NPT of the audio information using the RTP time stamp included in the received audio information; comparing the NPT of the video information and the NPT of the audio information to calculate a difference value; determining whether the calculated difference value is included in a specific synchronization region; and outputting the audio information and the video information when the calculated difference value is determined to be included in the specific synchronization region.

Abstract: Provided is an apparatus and method for transmitting and receiving a streaming service. An inter-arrival jitter may correspond to a delay variation in arrival time between TCP packets arriving at an apparatus for receiving the streaming service. The apparatus for receiving the streaming service may determine a de-jitter buffering time to absorb a network jitter before TS packets in a TCP packet is input to a T-STD buffer model. Based on the de-jitter buffering time, an initial playout delay lime at the apparatus for receiving the streaming service may be determined.

Abstract: A method and an apparatus for maintaining information security in a video multicasting service are provided. The method includes: generating a network abstraction layer unit using received video information; encrypting the network abstraction layer unit of the video information; realtime transport protocol (RTP) packetizing the encrypted network abstraction layer unit of the video information; recording unit format information and field information, included in the network abstraction layer of the video information being stored in a memory, in a header extension field of the RTP header; and transmitting the RTP packet including the encrypted video information to a routing device.

Abstract: Provided is an apparatus and method for transmitting and receiving a streaming service. The apparatus and method for transmitting and receiving a streaming service may use a light multimedia file suitable for a Hypertext Transfer Protocol (HTTP) streaming service. Using an HTTP hint track, an International Organization for Standardization (ISO) file generated in a non-interleaved storing scheme that is unsuitable for an HTTP streaming service may be converted into an ISO file based on an interleaved storing scheme that is suitable for an HTTP streaming service. An ISO file may include multiple media tracks for supporting multiple bitrates and resolutions. Chunk data of media tracks that provide multiple multimedia qualities may be effectively acquired, and a light ISO file suitable for an HTTP streaming service may be generated by storing the acquired chunk data in an interleaved scheme.

Abstract: A method of providing timing information for synchronizing packet streams delivered from a first server and a second server, respectively, that are different from each other under hybrid delivery service environment is provided. The first server delivers a first media object and the second server delivers a second media object. The timing information for synchronizing a second packet including the second media object and a first packet including the first media object is generated in the second server. The timing information and the second packet including the second media object are provided from the second server to the client.

Abstract: A method for generating and processing a hierarchical packetized elementary stream (PES) packet for digital satellite broadcasting based on SVC (Scalable Video Coding) video is disclosed. That is, when SVC video is applied to a digital satellite broadcasting system, a transmitter side can generate a hierarchical PES packet in consideration of a hierarchical structure of SVC video and a receiver side can effectively process a received hierarchical PES packet.

Abstract: An HTTP based video streaming apparatus and method of a mobile communication system is disclosed. A memory, such as a storing disk, stores content files received from a server of a transmitting party, a random access searching unit searches the random access point in the memory and transmits a content file request message to the transmitting server if the random access point does not exist in the memory, and a display unit displays the files from the random access point. Therefore, HTTP streaming service from a random point required by a user can be provided when the streaming has begun, and the random access function can be supported by even if the part required by the user has not yet been transmitted to receiving party.

Abstract: Provided is a real-time streaming protocol (RTSP) based progressive streaming method. The progressive streaming method based on a real-time streaming protocol, wherein a server transfers SDP information and performs streaming of a contents file to a client connected, the method including the steps of: a) if a “pause” request message is received from the client, transmitting a “pause” response message including the number of TCP packets already transferred to the client, and pausing streaming of the contents file; and b) if a “replay” request message including the number of the TCP packet to be transferred is received from the client, transmitting a “replay” response message and restarting transmission of the TCP packets from the next TCP packet to the TCP packet transferred to the client before the contents file is paused.

Abstract: A system and method for converting a codec of image data is provided. The system includes a syntax converter for selectively converting first image data having a first syntax into second image data having a second syntax in response to a comparison of the first image data and the second image data, and a decoder for decoding a bit stream outputted from the syntax converter.

Abstract: A source-channel combined coding method including: determining whether a channel signal-to-noise ratio (SNR) is varied or not; when it is determined that the channel SNR is varied, selecting a MODCOD suitable for the channel SNR by referring to a first table defining an SNR threshold value at which data transmission is performed without an error, for each MODCOD designating a low density parity check (LDPC) code rate and a modulation scheme; calculating a source coding rate by using an effective information bit rate of the selected MODCOD; extracting network abstraction layer (NAL) units for each layer from an inputted video frame so as to satisfy the calculated source coding rate, and packetizing the extracted NAL units; binding packets to configure a baseband (BB) frame; and LDPC coding and modulating the BB frame through the code rate and the modulation scheme which are designated by the selected MODCOD.

Abstract: A method and an apparatus for maintaining information security in a video multicasting service are provided. The method includes: generating a network abstraction layer unit using received video information; encrypting the network abstraction layer unit of the video information; realtime transport protocol (RTP) packetizing the encrypted network abstraction layer unit of the video information; recording unit format information and field information, included in the network abstraction layer of the video information being stored in a memory, in a header extension field of the RTP header; and transmitting the RTP packet including the encrypted video information to a routing device.

Abstract: A method of supporting synchronization of Scalable Video Coding (SVC) information and Advanced Audio Coding (AAC) information using a Normal Play Time (NPT), the method including: receiving video information using a decoding apparatus; receiving audio information using the decoding apparatus; calculating the NPT of the video information using a Real-time Transport Protocol (RTP) time stamp included in the received video information; calculating the NPT of the audio information using the RTP time stamp included in the received audio information; comparing the NPT of the video information and the NPT of the audio information to calculate a difference value; determining whether the calculated difference value is included in a specific synchronization region; and outputting the audio information and the video information when the calculated difference value is determined to be included in the specific synchronization region.

Abstract: A multimedia streaming service system is provided that includes a VOD server to sequentially transmit a header (moov) and media data (mdat) of MP4 contents in a TCP packet and a client to transmit a streaming service request signal in HTTP to the VOD server. The client may accumulate the media data (mdat) received from the VOD server in a decoder buffer for a predetermined time, and reproduce the data on a real time basis. A guaranteed rate of QoS may be enhanced as compared to an RTP/UDP-based streaming method. A service delay time may be reduced as compared with a TCP-based downloading method, thereby implementing contents on a real time basis.

Abstract: The present invention relates to a method for encoding a signal of a wireless communication system, the method comprising dividing a current frame of the signal into a plurality of GOBs (Groups of Blocks) each having a certain size, determining whether a current GOB to be encoded of the plurality of GOBs is a first GOB of the current frame, calculating a control parameter value of the current GOB according to whether the current GOB is the first GOB of the current frame, controlling an encoding bit rate of the current GOB according to the control parameter value, and encoding the current GOB. Preferably, a hybrid method wherein an inter-frame GOB update method and an intra-frame GOB update method is used, so that a bit rate change between frames is reduced and data transmission of a channel is efficiently made to therefore provide a user with optimum image quality.

Abstract: An apparatus for downloading a multimedia file including a file converter configured to convert a larger multimedia file into a smaller multimedia file by deleting prescribed medial information based on a media format contained in the larger file. Further, the file converter converts the larger file into the smaller file by deleting multi bit-rate media not corresponding to a selected bit rate or by deleting enhancement layer video.

Abstract: A method for setting a motion vector of a digital video including calculating a final motion vector allocated to a resolution-reduced macroblock using two motion vectors having a highest correlation among each other out of motion vectors of four adjacent macroblocks.

Abstract: A method for adaptively estimating a transmission rate of multimedia data by monitoring an RTCP network state is provided. The method comprises receiving a real-time transport protocol (RTCP) receiver report packet from a multimedia data reception unit; detecting packet loss rate from the RTCP receiver report packet; and adaptively estimating an available transmission rate according to a range within which the packet loss rate belongs.

Abstract: Provided is a streaming service system and method for a universal video access based on scalable video coding (SVC). A gateway to provide a streaming service may include: an SVC content file parser to receive an SVC content file from a streaming server, and to separately extract an SVC network abstraction layer (NAL unit) of a base layer and an SVC NAL unit of a scalable enhancement layer from SVC NAL units that are included in the SVC content file; an SVC NAL selection unit to select an SVC NAL unit corresponding to a client type of each of terminals; and a packet generation unit to transmit the selected SVC NAL unit to a corresponding terminal.

Abstract: A method for generating and processing a hierarchical packetized elementary stream (PES) packet for digital satellite broadcasting based on SVC (Scalable Video Coding) video is disclosed. That is, when SVC video is applied to a digital satellite broadcasting system, a transmitter side can generate a hierarchical PES packet in consideration of a hierarchical structure of SVC video and a receiver side can effectively process a received hierarchical PES packet.

Abstract: A method for judging a lost block characteristic in a video processing system including certifying whether a lost block exists among transmitted video blocks, calculating a temporal difference cost1 between neighborhood pixels of the lost block in a present frame and a previous frame, and calculating a motion vector distribution value cost2 of peripheral blocks of the lost video block. The method also includes comparing the temporal difference cost1 and the motion vector distribution value cost2 with preset threshold values, and determining a characteristic of the lost block based on a result of the comparison. The automatically judged characteristic of the lost block is utilized as information for recovering the lost block to thereby reproduce a recovery video close to the original video.