Abstract: A decoding circuit inputs a data stream D3 which has been multiplexed at different sampling frequencies, and separates it into two audio data D1 and D2 at different sampling frequencies, which it supplies to buffers. The output of the buffer is inputted to an up-sampling circuit, which, along with performing up-sampling at a frequency which corresponds to a processing unit of data of which the time delay amount is predetermined, also suppresses aliasing distortion. On the other hand, the output of the buffer is inputted to a delay buffer, which delays it by a time delay amount the same as that due to the up-sampling circuit. By doing this, the reproducing phases of the two streams of audio signals are coincided.

Abstract: An encoder comprises an input device for sampling an input signal at predetermined time intervals to obtain sampled data on a temporal axis, a conversion device for converting the sampled data on the temporal axis to spectral data on a frequency axis, a quantization device for quantizing the spectral data on the frequency axis, and an output device for outputting a resultant value of quantization as an encoded bit stream. The quantization device comprises an expected-value-of-quantization adjustment portion for determining an expected value of quantization for a specific sub-band on the frequency axis, and a quantization portion for determining a quantization coefficient for the specific sub-band, and quantizing each of a plurality of spectral data contained in the specific sub-band using the quantization coefficient for the specific sub-band.

Abstract: According to the data amount and the nature of a video stream and an audio stream included in a program stream which is to be decoded, an audio and video processing apparatus performs processing while allocating higher priority to one or the other of the video and audio streams. Without any increase in circuit complexity or clock speed, this apparatus can reproduce streams in at least two formats, in which the ratios of the amounts of encoded signal data and of the amounts of calculation required for decoding for the video and the audio are very different.

Abstract: A device of the present invention is an exponential calculation device for calculating x{circumflex over ( )}(a/b) (where a and b are each an integer constant) for a given input value of x. The device includes: an input control section for outputting a value of x′, wherein x′=x when x≦A (where A is a threshold value within a variable range of x) and x′=x/2{circumflex over ( )}b when x>A; a core section for outputting a value of z′=x′{circumflex over ( )}(a/b); and an output control section for outputting a value of z, wherein z=z′ when x≦A and z=z′*2{circumflex over ( )}a when x>A.

Abstract: A decoding device for decoding a data stream includes a decoding table including a first region and a second region; a first decoder; and a second decoder. The first region defines a relationship between first data having a predetermined number of bits and a result of decoding a portion of the first data having bits smaller than or equal to the predetermined number. The second region defines a relationship between concatenated data obtained by concatenating the first data with second data having additional bits and a result of decoding the concatenated data. The first decoder reads the first data from the data stream; decodes the portion of the first data based on the first region; determines whether the decoding of the portion of the first data is completed or not; and when the decoding of the portion of the first data is completed, outputs a result of the decoding of the portion of the first data.

Abstract: A decoding device for decoding a bit stream defined by MPEG2 Audio Multichannel is provided. The bit stream including an MPEG1 compatible area and an MPEG2 multichannel extended area, the MPEG1 compatible area including MPEG1 side information. The decoding device includes: MPEG1 decoding means for decoding the MPEG1 compatible area; MC decoding means for decoding the MPEG2 multichannel extended area; and MC header detection means for executing a first processing including locating a position of a header of the MPEG2 multichannel extended area based on the MPEG1 side information and shifting a read position of the bit stream to the position of the header.

Abstract: An audio decoding device for decoding coded audio information with multiple channels includes a coded information memory section for storing the coded audio information; an information transmission section for reading the coded audio information stored at an arbitrary position in the coded information memory section; and an audio decoding section for decoding the coded audio information read by the information transmission section and outputting the resultant audio information in accordance with a time axis.

Abstract: A compressed code decoding device of the present invention includes: a decoding section for receiving a plurality of groups of blocks of compressed codes and decoding each of the blocks of compressed codes; a buffer section for storing decoded signals decoded by the decoding section; a reproduction time acquisition section for acquiring a reproduction time at which to reproduce a predetermined one of the blocks; an output section for externally outputting the decoded signals stored in the buffer section; a detection section for detecting that the predetermined block of compressed codes has been decoded and output via the output section; an addition section for, at a time when the detection section detects that the predetermined block has been output, adding a time required for reproducing the predetermined block to the reproduction time acquired by the reproduction time acquisition section so as to produce a synchronization time; a synchronization section for comparing the synchronization time produced by the