Abstract: A binaural decoder for an MPEG surround stream, which decodes an MPEG surround stream into a stereo 3D signal, and a decoding method thereof. The method includes dividing a compressed audio stream and head related transfer function (HRTF) data into subbands, selecting predetermined subbands of the HRTF data divided into subbands and filtering the HRTF data to obtain the selected subbands, decoding the audio stream divided into subbands into a stream of multi-channel audio data with respect to subbands according to spatial additional information, and binaural-synthesizing the HRTF data of the selected subbands with the multi-channel audio data of corresponding subbands.

Abstract: A method of encrypting data transmitted from a first device to a second device, performed by using an Advanced Encryption Standard (AES) encryption algorithm, includes obtaining size information of an encryption key and size information of data that is to be encrypted and includes a plurality of bits; encrypting a first bit group, which is at least one bit corresponding to a size of the encryption key, among the plurality of bits, by using the encryption key; selecting a third bit group, which is at least one bit of the encrypted first bit group based on size information of the encryption key and a size of a second bit group including bits that are different from the first bit group among the plurality of bits; and encrypting the second bit group and the selected third bit group by using the encryption key.

Abstract: A device and a method for processing an image by a multimedia device that supports encryption and decryption are provided. The device includes a thumbnail image of an original image is obtained and the original image is encrypted using a first encryption scheme. An encrypted image frame is generated such that the encrypted image frame includes an identity field in which marker information is recorded between a first image field in which the obtained thumbnail image is recorded and a second image field in which the encrypted original image is recorded. The marker information indicates whether the encrypted image frame includes the second image field.

Abstract: A method of managing an image by an electronic device may include: generating a first encryption image by encrypting a first image; acquiring bitstream data corresponding to a second image related to the first image; generating a changed image by combining at least some of the bitstream data and the first encryption image; and transmitting the changed image to an external electronic device.

Abstract: An apparatus and method for a sensor network, machine-to-machine (M2M) communication, machine type communication (MTC), and Internet of things (IoT) are disclosed. The disclosure may be applied to, for example, intelligent services related to the above technologies, in conjunction with smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail business, security, and safety related services. The method includes generating first image data by resizing original image data to a predetermined size, inserting watermark data into the first image data, and adding difference data corresponding to the difference between the original image data and the first image data to second image data that is image data in which the watermark data is inserted.

Abstract: Exemplary embodiments may provide a method of encoding an audio signal. The method includes: segmenting the audio signal into a plurality of frames, wherein each of the frames includes M samples and M is a natural number greater than one; applying a first window, a second window, and at least one third window to the frames, wherein a length of the second window is longer than a length of the first window, and a length of the third window is longer than the length of the first window and shorter than the length of the second window; time-frequency transforming the frames to which the first window, the second window, and the at least one third window have been applied; and generating a bitstream including the time-frequency transformed frames.

Abstract: A secure communication apparatus may include a security module for generating an encrypted bitstream by encrypting at least a portion of data forming a bitstream and inserting at least a portion of key information used in the encryption into the bitstream and for decrypting encrypted data by acquiring at least a portion of key information for the decryption from a received encrypted bitstream, and a communication module for transmitting and receiving the encrypted bitstream.

Abstract: Provided are a multi-channel audio down-mixing method and apparatus for selecting down-mix target channels based on a calculation of correlations between channels and then down-mixing the down-mix target channels. The method includes: calculating correlations between channels of multi-channel audio; selecting a first channel and a second channel, among the channels of the multi-channel audio, that are to be down-mixed, based on the calculated correlations; and down-mixing the selected first channel and the selected second channel.

Abstract: Provided are an apparatus and a method for encoding and decoding audio signals, in which when determining a masking threshold according to a psychoacoustic model, accurate results may be obtained for a short window-based audio signal as well as for a long window-based audio signal. The apparatus for encoding audio signals according to the present invention comprises a masking threshold determining unit configured to determine, on the basis of a frame length of a first window having a divided audio signal, a masking threshold for a second window that has a different frame length from that of the first window.

Abstract: Provided are a method and apparatus for encoding/decoding stereo audio. In the method for encoding stereo audio, stereo audio is encoded based on at least one of the phase difference between first and second channel audios and information on an angle made by a vector on the intensity of mono-audio and a vector on the intensity of the first channel audio or a vector on the intensity of the second channel audio. Thus, the number of encoded parameters is minimized so that a compression ratio in the encoding of the stereo audio is improved.

Abstract: Methods and apparatuses for encoding and decoding an audio signal are provided, a method of encoding an audio signal including: receiving the audio signal including information about a moving sound source; receiving position information about the moving sound source; generating dynamic track information indicating motion of the moving sound source by using the position information; and encoding the audio signal and the dynamic track information.

Abstract: A binaural decoder for an MPEG surround stream, which decodes an MPEG surround stream into a stereo 3D signal, and a decoding method thereof.

Abstract: Provided are a user terminal device and a secured communication method thereof. The secured communication method includes: encrypting a voice bitstream including voice data corresponding to a user voice for a call in a security mode between the user terminal device and another user terminal device; inserting the encrypted voice bitstream into a video transmission stream; and transmitting the video transmission stream, into which the encrypted voice bitstream is inserted, to the other user terminal device.

Abstract: A binaural decoder for an MPEG surround stream, which decodes an MPEG surround stream into a stereo 3D signal, and a decoding method thereof. The method includes dividing a compressed audio stream and head related transfer function (HRTF) data into subbands, selecting predetermined subbands of the HRTF data divided into subbands and filtering the HRTF data to obtain the selected subbands, decoding the audio stream divided into subbands into a stream of multi-channel audio data with respect to subbands according to spatial additional information, and binaural-synthesizing the HRTF data of the selected subbands with the multi-channel audio data of corresponding subbands.

Abstract: Provided is a signal processing method for processing a bitstream, an information storage medium including the bitstream, an encoding apparatus, and a decoding apparatus. The signal processing method includes: receiving a bitstream including additional information; extracting first information which is information associated with extraction of the additional information and is included in at least one of additional bitstream information, a skip field, and auxiliary data bits, which are included in the bitstream; and extracting and decoding the additional information by using the first information.

Abstract: A method processing a signal, an encoding apparatus, and a decoding apparatus are provided. The method of processing a signal includes restoring a down-mixed original signal using a re-quantized prediction parameter to generate a restored signal in an encoding apparatus; generating mute information indicating whether the down-mixed original signal has been muted, according to a value of the restored signal; and transmitting the mute information and the down-mixed original signal from the encoding apparatus to a decoding apparatus.

Abstract: A multi-channel audio signal encoding and decoding method and apparatus are provided. The multi-channel audio signal encoding method, the method including: obtaining semantic information for each channel; determining a degree of similarity between multi-channels based on the obtained semantic information for each channel; determining similar channels among the multi-channels based on the determined degree of similarity between the multi-channels; and determining spatial parameters between the similar channels and down-mixing audio signals of the similar channels.

Abstract: Encoding and decoding of residual signals are provided. In a method of encoding a residual signal of an audio signal, the residual signal is divided into a plurality of sections having different sizes, based on a change of the residual signal. Then, section division information representing information about the divided sections and section-by-section residual signal information representing characteristics of the sections of the residual signal are acquired. Thereafter, the residual signal is encoded based on the section division information and the section-by-section residual signal information.

Abstract: A method and apparatus which encode multi-channel audio signals and a method and apparatus which decode multi-channel audio signals. When encoding, a downmixed audio signal, first additional information for restoring multi-channel audio signals from the downmixed audio signal, and second additional information representing characteristics of a residual signal are multiplexed. When decoding, restored multi-channel audio signals having a predetermined phase difference are combined using the second additional information, and an audio signal of each channel is corrected, in order to improve quality of the restored audio signals.

Abstract: A method of encoding stereo audio that minimizes a number of pieces of side information required for parametric-encoding and parametric-decoding of the stereo audio. The side information may include parameters about interchannel intensity difference (IID), interchannel correlation (IC), overall phase difference (OPD), and interchannel phase difference (IPD), which are required to restore the mono audio to the stereo audio.