139results about "Compressed audio signal" patented technology

An audio-feature analyzer automatically detects points of change in audio signals to be processed. A central processing unit (CPU) obtains point-of-change information indicating positions of the points of change in the audio signals, and the point-of-change information is recorded on a data storage device. The CPU identifies point-of-change information in accordance with an instruction input by a user via a key operation unit, and audio data corresponding to the point-of-change information identified is located so that processing such as playback of audio data to be processed can be started therefrom.

A system and methods for permitting open access to data objects and for securing data within the data objects is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. The method includes the steps of (1) providing a data object comprising digital data and file format information; (2) embedding independent data into a data object; and (3) scrambling the data object to degrade the data object to a predetermined signal quality level. The steps of embedding and scrambling may be performed until a predetermined condition is met. The method may also include the steps of descrambling the data object to upgrade the data object to a predetermined signal quality level, and decoding the embedded independent data. The additional steps of descrambling and decoding may be performed until a predetermined condition is met. The predetermined condition may include, for example, reaching a desired signal quality of the data object.

A system and methods for permitting open access to data objects and for securing data within the data objects is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. The method includes the steps of (1) providing a data object comprising digital data and file format information; (2) embedding independent data into a data object; and (3) scrambling the data object to degrade the data object to a predetermined signal quality level. The steps of embedding and scrambling may be performed until a predetermined condition is met. The method may also include the steps of descrambling the data object to upgrade the data object to a predetermined signal quality level, and decoding the embedded independent data. The additional steps of descrambling and decoding may be performed until a predetermined condition is met. The predetermined condition may include, for example, reaching a desired signal quality of the data object.

An apparatus for processing an encoded signal and method thereof are disclosed, by which an audio signal can be compressed and reconstructed in higher efficiency.An audio signal processing method includes the steps of identifying whether a type of an audio signal is a music using first type information, if the type of the audio signal is not the music signal, identifying whether the type of the audio signal is a speech signal or a mixed signal using second type information, and if the type of the audio signal is determined as either the speech signal or the mixed signal, reconstructing the audio signal according to a coding scheme applied per frame using coding identification information. If the type of the audio signal is the music signal, the first type information is received only. If the type of the audio signal is the speech signal or the mixed signal, both of the first type information and the second type information are received.Accordingly, various kinds of audio signals can be encoded / decoded in higher efficiency.

A combination CD-ROM and MP3 recorder / player playing a CD-ROM decodes 16-bit ISO standard code words into an audio wave form converts this wave form to sound while encoding and digitizing the wave form into 24-bit MP3 format digital data. To conserve power the MP3 data is buffered in a solid state memory, preferably of the FLASH or DRAM type, before being written to a hard disk. Both reading of the CD / ROM and encoding the read contents as MP3 data, and interchange of MP3 data with other recorder / players, can be accomplished at greater than real-time play rates, permitting that, most typically, some 1200+ musical works can transferred expediently.

Recorded audio data is compressed to obtain a condensed version, by first selecting a number of subsequent non-overlapping segments of the audio data, then reducing each segment by temporal compression and combining the reduced segments into a shortened version which can be output. The temporal compression may be made with a local compression factor which varies between the segments. The segmenting may be chosen based on an innovation signal derived from the audio data itself to indicate a content change rate in the audio data.

An information reproduction apparatus for performing special reproducing operations including fast forward and fast reverse operations on an audio-video material. The information reproducing apparatus is capable of reading and reproducing information having a plurality of clips wherein the size of the recording medium access unit or cluster is set at a common multiple of the size of the recording medium minimum accessible unit or sector and the size of the minimum process unit or decoding packet size in the information material reproducing apparatus.

A lossless encoder and decoder are provided for transmitting a multichannel signal on a medium such as DVD-Audio. The encoder accepts additionally a downmix specification and splits the encoded stream into two substreams, such that a two-channel decoder of meagre computational power can implement the downmix specification by decoding one substream, while a multichannel decoder can decode the original multichannel signal losslessly using both substreams. Further features provide for efficient implementation on 24-bit processors, for confirmation of lossless reproduction to the user, and for benign behaviour in the case of downmix specifications that result in overload. The principle is also extended to mixed-rate signals, where for example some input channels are sampled at 48 kHz and some are sampled at 96 kHz.

A combination CD-ROM and MP3 recorder / player playing a CD-ROM decodes 16-bit ISO standard code words into an audio wave form converts this wave form to sound while encoding and digitizing the wave form into 24-bit MP3 format digital data. To conserve power the MP3 data is buffered in a solid state memory, preferably of the FLASH or DRAM type, before being written to a hard disk. Both reading of the CD / ROM and encoding the read contents as MP3 data, and interchange of MP3 data with other recorder / players, can be accomplished at greater than real-time play rates, permitting that, most typically, some 1200+ musical works can transferred expediently.

A lossless encoder and decoder are provided for transmitting a multichannel signal on a medium such as DVD-Audio. The encoder accepts additionally a downmix specification and splits the encoded stream into two substreams, such that a two-channel decoder of meagre computational power can implement the downmix specification by decoding one substream, while a multichannel decoder can decode the original multichannel signal losslessly using both substreams. Further features provide for efficient implementation on 24-bit processors, for confirmation of lossless reproduction to the user, and for benign behaviour in the case of downmix specifications that result in overload. The principle is also extended to mixed-rate signals, where for example some input channels are sampled at 48 kHz and some are sampled at 96 kHz

A system for selection by a user and delivery to the user over an internetwork transmission channel of selected audio data files at a delivery rate of at least twice the delivery rate for normal, audibly perceptible playback of an audio data file. The user registers the user's selection of audio material with a central library of audio and / or text data files, and a digitized and optionally compressed omnibus file containing the user's selections is prepared and transmitted to the user at a high data transfer rate. The user receives downloads the selected data files to a personal computer or to a portable storage and playback unit (SPU) that may store and play back digitized text or audio data, using a docking station. The user carries this SPU until the user has an opportunity to audio process and play back the text or audio data files in audibly perceptible form.

An apparatus for processing an encoded signal and method thereof are disclosed, by which an audio signal can be compressed and reconstructed in higher efficiency. An audio signal processing method includes the steps of identifying whether a coding type of the audio signal is a music signal coding type using first type information, if the coding type of the audio signal is not the music signal coding type, identifying whether the coding type of the audio signal is a speech signal coding type or a mixed signal coding type using second type information, if the coding type of the audio signal is the mixed signal coding type, extracting spectral data and a linear predictive coefficient from the audio signal, generating a residual signal for linear prediction by performing inverse frequency conversion on the spectral data, reconstructing the audio signal by performing linear prediction coding on the linear predictive coefficient and the residual signal, and reconstructing a high frequency region signal using an extension base signal corresponding to a partial region of the reconstructed audio signal and band extension information. Accordingly, various kinds of audio signals can be encoded / decoded in higher efficiency.

An audio disk has a first audio zone and a second audio zone. In the first audio zone, both of a plurality of tracks each including a single piece of music and a first management information including first control information for allowing each track to be reproduced are recorded. The music is composed of audio data produced from either a linear PCM signal or a signal produced by applying lossless compression to the linear PCM signal. In the second audio zone, music composed of audio signal produced under lossy compression, a plurality of files each storing a signal of a single piece of music subjected to the lossy compression, and second management information including second control information for allowing each file to be reproduced are recorded. Each piece of music stored in each file corresponds to the music included in any one of the tracks in the first audio zone.

An apparatus and method for adjusting the output level of audio data to be reproduced can adjust any one of audio files of different types to a consistent or reference level prior to amplifying at a desired level (e.g., user selected volume). Therefore, digital audio systems and methods according to embodiments of the present invention can reproduce audio files of various types such as an MP3 audio type, MPEG2 audio type and AC3 audio type, and the output level of audio data to be reproduced of each of the audio files can be adjusted to a value corresponding to an audio volume level set by a user, which can prevent or reduce the output levels of the audio data from becoming different because of audio recording levels and recording formats of the audio files set in creation or recording processes thereof.

In a reproduction apparatus, for reproducing an original signal conveyed as main data by a data medium such as a recording disk or broadcasting system, with medium protection data which are specific to the data medium being conveyed together with the main data, the apparatus includes a section for generating apparatus protection data which are specific to the reproduction apparatus, a section for combining the apparatus protection data with the medium protection data to define a protection level, and a section for applying the protection level to restrict reproduction of the original signal, with stepwise variations in restriction occurring in accordance with changes in protection level. The medium protection data may include information for specifying restricted reproduction of portions of the original signal, such as by producing degraded resolution within specified regions of specified frames of a video signal.

In electronic devices such as combination CD-ROM and MP3 recorder / players power is conserved by buffering audio or visual data in a solid state memory, preferably of the FLASH or DRAM type, before writing the data to a rotating hard disk. Alternatively, audio and / or visual data, including musical works and still pictures and video, read from a rotating hard disk may be buffered in the same solid state memory while being played. By rotating the hard disk drive only for transfer of audio-visual data, which is normally compressed, in blocks, the hard drive may be stopped both during relative lengthy accumulation, and / or use, of this data, and energy conserved.

A method and device for recording information signals on a partly recorded writable record carrier (11), e.g., an optical disc. An information signal represents at least one information unit. The record carrier has a recording track which includes pre-formed track position information indicative of locations for recording the information units. From the information signal, a modulated signal is generated having successive frames, each frame including a synchronizing signal. The modulated signal is recorded at a one of the locations, while maintaining a fixed relationship between the track position information and the synchronizing signals. In the event that the location is after and adjacent to an already recorded location, the recording is started at a link position (31) before the end of a last frame of the earlier recorded information signal, at a predefined distance before a first synchronizing signal (30) of the modulated signal.

Disclosed is an MPEG portable sound reproducing system and a method for reproducing sound data compressed using the MPEG method. The inventive system includes power supply means for supplying operational power to the system, the power supply means being realized through a secondary battery; power processing means for rectifying power supplied from the power supply means to stable voltage and current; information display means for displaying numbers and combinations of letters related to operational states of the system; control means for controlling all operations of converting and reproducing sound data compressed using the MPEG method; data storage means for storing MPEG-compressed sound data in a designated address according to signals output from the control means; information selecting means for selecting general operations to reproduce, download, and apply selected sound data stored in the data storage means; sound reproducing means for converting sound data stored in the data storage means into a format audible to users according to signals output from the control means; and transmitting / receiving means for transmitting and receiving sound data and program data from external devices.

An audio device includes a DVD player for decoding an input audio signal and for outputting a digital audio signal, an audio amplifier for outputting an analog audio signal based on the digital audio signal, an audio decoder for detecting a change of an audio attribute, a decoding suspension unit for muting an output from the audio amplifier and temporarily suspending an operation of the decoder when the change of the attribute is detected, and a setting changing unit for changing operation conditions of the audio amplifier so as to correspond to the changed audio attribute when a muting part operates.

An apparatus and method for processing a stream compressed and encoded with a variable length code (VLC) in a predetermined unit by detecting an error flag that has been set. The flag corresponds to a position of an error when the error is contained in the stream. Adding information representing an end of the VLC, based on the error flag, to the position corresponding to the error flag in a string of the VLC containing the error flag. Thus, the VLC after the error flag can be discarded. Additionally, an apparatus and method for processing a stream encoded with a VLC by detecting a code symbol that does not match a parameter representing the VLC from the VLC stream. Correcting the stream based on the detected result, and designating the start of the next process after the detected result has been obtained. Thus, even if a stream containing an irregular VLC is input, the apparatus can be operated in a stable mode.

System and method for encoding, transmitting and decoding audio data. Audio bit steam syntax is re-organized to allow system optimizations that work well with memory latency and memory burst operations. Multiple small entropy coding tables are stored in RAM and loaded to on-chip memory as needed. Audio prediction is pipelined in the bitstream syntax. Intra frames, independent of other frames in the bitstream, are included in the bitstream for error recovery and channel change. New algorithms are implemented in legacy syntax by including the new information in the user data space of the audio frame. The new decoder can use projection to determine where the new information is and read ahead in the stream. Audio prediction from the immediately previous frame is restricted. Audio prediction is performed across channels within a single audio frame. A variable re-order function comprises storing channels of data to DRAM in the order they are decoded and reading them out in presentation order.

The present invention provides a high-speed digital audio recorder, capable of converting collections of CDs quickly to digital audio formats, such as MP3, AAC, WAV, WMV, and others. This recorder consists of a plurality of computing units each equipped with specialized software, tailored specifically to the conversion process. In addition, the system offers the ability to inject identifiers, such as ID3 tags, watermarks, or digital rights into each track, thereby offering a powerful deterrent to the unlawful sharing of these digital files with others.

An AV data recording apparatus and an AV data recording method are provided, in which even in the case of using the UDF file system, seeking can be minimized. The AV data recording method has file management information for managing continuous blocks on a disk as an extent, and dividing the extent into groups so as to manage the extent as a file, wherein a new directory is created on a disk, and a not recorded but allocated extent is kept as a reservation region for recording file management information.

According to one embodiment, a preset amount of padding data is added while a block number corresponding to a detecting period of sync information which becomes shorter is used as a packing unit when the detecting period of the sync information becomes shorter than an original period, and a block number corresponding to a detecting period of the sync information which becomes longer is divided while an original number of blocks contained in one packing unit is set as an upper limit and a preset amount of padding data is added with each divided block number used as a packing unit when the detecting period of the sync information becomes longer than the original period.

A high frequency compensator includes a down sampler configured to perform ½ down-sampling for a compressed and expanded digital audio signal. An up sampler is configured to perform double up-sampling for an output signal of the down-sampler. A digital low-pass filter is configured to filter an output signal of the up sampler. A digital high-pass filter is configured to filter an output signal of the digital low-pass filter. An adder is configured to add an output signal of the digital high-pass filter to the compressed and expanded digital audio signal, and to output a digital audio signal generated by the adding.

An audio data recording / reproduction system which is simple in configuration, convenient and safe to use, and an audio data recording medium therefor is to be provided. A music data recording medium is configured in which power information correlated to the average sound pressure power of audio data matching music pieces (music programs) is recorded, appended to each of the music pieces (music programs). In the audio data recording / reproduction system, its encoding unit is provided with a power information generating section which, receiving digital audio data matching a music piece (music program), generates power information correlated to the average sound pressure power of the audio data, and records in the recording unit the generated power information made relevant to compressed data resulting from the compression of the digital audio data; and its decoding unit extracts the power information, restores the original digital audio data from the compressed audio data, and outputs the data adjusted on the basis of the power information, or outputs the restored digital audio data and the power information.

To provide an information reproduction apparatus which can consecutively reproduce a plurality of clips of an information material without the need for preparing resources of two channels and without using a special, dedicated encoder a write finish flag generator is provided which sets a write finish flag WF at a time point when writing of a cluster of a certain clip from a recording medium to an information material storage unit is finished in a case where at least part of the last cluster of the preceding clip is invalid data in reproducing the clip, preceding the clip, of an information material supplied from the information material storage unit.