Yamaha Corporation

Kazunobu Fujiwara

Mikio Ogusu

Kei Tanaka

Kazuhiko Honda

Katsuichi Osakabe

Tadashi Sugiyama

Masaya Kano

Sadayuki Narusawa

Kunihiro Kumagai

Toshihito Uchiyama

Minoru Saito

Kano Masaya

An audio device (e.g. an AV amplifier), with a plurality of audio output terminals according to the HDMI standard, converts audio data of a source device into audio signals suited to audio reproduction abilities (e.g. channel counts) of sink devices. The audio device stores a plurality of audio reproduction ability information describing the predetermined channel count thereof and the channel counts of sink devices, wherein arbitrary audio reproduction ability information precluding audio reproduction ability information of a sink device with the smallest channel count is provided to a source device. The audio device performs down-mixing on audio signals with respect to a sink device whose channel count is smaller than the predetermined channel count, while the audio device performs signal processing on audio signals with respect to a sink device whose channel count is larger than the predetermined channel count.

Audio device

There is generated a rhythm corresponding to a designated tempo and meter of a music piece to be recorded. Performance of a musical instrument is started at specific timing according to the generated rhythm, and the musical information resulting from the performance is recorded onto an MD (Mini Disk). The address on the MD read out when the performance of the music piece is started is retrieved as a start address of the music piece. After the recording, the retrieved start address is recorded onto the UTOC (User's-table-of-contents) area of the disk along with the designated tempo and meter. By reading out the start address, tempo and meter to calculate a measure number and start address of a desired measure on the basis of the read out information, display of a measure number being currently reproduced and quick access to the starting point of any desired measure can be achieved. In applications where plural channels are involved, part information indicative of performance parts assigned and recorded on the individual recording channels is also recorded onto the UTOC area. When necessary, the part information is visually displayed. In ping-pong recording, performance parts to be mixed are additively synthesized on the basis of the recorded part information and then recorded onto the UTOC area as part information for a channel where the mixed output is to be recorded.

Musical information recording and reproducing technique for use with a recording medium having a UTOC area

The present invention provides an audio data recording medium reproducer, wherein CPUwhich writes audio data read by readerinto buffer memoryand buffer memory controllerwhich transfers the data to buffer memoryand inputs it into DACat a predetermined data rate are connected by a bus, and furthermore, CPUfor controlling a user interface is separately provided. Provision of a plurality of such simple controllers reduces costs to be lower than in the case of providing one high-performance controller. Furthermore, it also becomes possible to separately construct the respective functional parts as units.

Reproduction of audio data from recording medium

Push-pull signal is created on the basis of reflected-light detection signals output from four divided light receiving elements that receive a reflection of a recording laser light beam off an optical disk. The push-pull signal is sent to a gain variation circuit. The push-pull signal is normalized by setting the gain of the gain variation circuit to a low level in response to a mark forming section of a recording signal, but to a high level in response to a blank forming section of the recording signal. Wobble detection and pre-pit detection are performed on the basis of the normalized push-pull signal.

Optical disk recording apparatus having push-pull signal processing circuit, wobble extraction circuit and pre-pit detection circuit

For each sync frame, an AND circuit detects whether a pre-pit synchronization signal can be obtained within a window set by a timing generator. Detection result of the AND circuit is held by a shift register, where it is shifted in response to each sync frame. On the basis of a parallel output from the shift register, a decoder determines whether the detection of the pre-pit synchronization signal is accurate or erroneous. Count value of a counter is incremented by one each time the decoder determines that the detection of the pre-pit synchronization signal is accurate, but is decremented by one each time the decoder determines that the detection of the pre-pit synchronization signal is erroneous. Identification section identifies stability/instability of the pre-pit synchronization signal detection.

METHODS FOR IDENTIFYING ERRONEOUS DETECTION OF PRE-PIT SYNCHRONIZATION BIT ON OPTICAL DISC AND IDENTIFYING STABILITY/INSTABILITY OF PRE-PIT SYNCHRONIZATION BIT DETECTION, AND ELECTRIC CIRCUITS THEREFOR

Musical information recording and reproducing technique for use with a

Program information of plural channels is recorded on an optical magnetic disk in such a manner that the program information can be simultaneously reproduced together from the disk. Once other program information is overwritten on part of any of the recording channels of the disk that has become unnecessary, a UTOC generation/UTOC recording/UTOC memory controlling section generates UTOC information that designates the overwritten section as a position to be reproduced and a section other than the overwritten section as a position to be silenced or muted, and records the generated UTOC information onto the UTOC area of the optical magnetic disk. As reproduction from the optical magnetic disk is performed, the UTOC information is read out so that reproduction signal is output at the position to be reproduced, and silence signal is output at the position to be silenced.

Information recording/reproducing technique to record plural-channel

Test EFM signal reproduced from an optical disk is converted through a slicer into binary value, and a synchronizing signal having an 11T--11T signal pattern is detected by a frame synchronization circuit. Upon detection of the synchronizing signal, a detection timing counter predicts timing when a next synchronizing signal will be detected. The respective level values at the intermediate points of the former and latter 11T sections of the synchronizing signal are sampled and held by sample and hold circuits. Once a next synchronizing signal is detected at the predicted timing, a synchronization determination circuit transfers the outputs of the sample and hold circuits to another sample and hold circuits. The outputs of the other sample and hold circuit are averaged by filters and asymmetry is calculated by an asymmetry calculation circuit. On the basis of the calculated asymmetry, a determination circuit determines an optimum recording power value.

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Hamamatsu, Japan

Kazunobu Fujiwara