Abstract: A low-cost, real-time solution is presented for compensating memoryless non-linear distortion in an audio transducer. The playback audio system estimates signal amplitude and velocity, looks up a scale factor from a look-up table (LUT) for the defined pair (amplitude, velocity) (or computes the scale factor for a polynomial approximation to the LUT), and applies the scale factor to the signal amplitude. The scale factor is an estimate of the transducer's memoryless nonlinear distortion at a point in its phase plane given by (amplitude, velocity), which is found by applying a test signal having a known signal amplitude and velocity to the transducer, measuring a recorded signal amplitude and setting the scale factor equal to the ratio of the test signal amplitude to the recorded signal amplitude. Scaling can be used to either pre- or post-compensate the audio signal depending on the audio transducer.

Abstract: Digital audio samples are represented as a product of scale factors codes and corresponding quantity codes, sometimes referred to as exponent/mantissa format. To compress audio data, scale factors are organized by sample time and frequency either by filtering or frequency transformation, into a two-dimensional frame. The frame may be decomposed into “tiles” by partition. One or more such scale factor tiles are compressed by transformation by a two-dimensional, orthogonal transformation such as a two dimensional discrete cosine transform. Optional further encoding is applied to reduce redundancy. A decoding method and an encoded machine readable medium complement the method of encoding.

Abstract: Methods and apparatus are provided for the creation and utilization of unique compressed data stream compositions, structures and formats which allow for the alteration of the data stream's data rate without first decoding the data stream back to its uncompressed form and then re-encoding the resulting uncompressed data at a different data rate. Such methods and apparatus perform this data rate alteration, known as scaling, such that optimal quality is maintained at each scaled data rate, while performing said scaling with low computational complexity. In addition, the present invention provides for data rate alteration in small increments. A unique application for the disclosed bit rate scaling method and apparatus is also described.

Abstract: In a motion picture subtitle system a shutter such as a mechanical dowser, LCLV, or E/O diffuser is inserted in the optical path between the supplemental projector and the motion picture screen and synchronized to the projection of the subtitles to reduce visual artifacts and enhance the cinematic presentation. A controller is arranged to receive the subtitles from a storage medium, to provide the subtitles to the supplemental projector in synchronism with the projection of the motion picture, and to alternately cause the shutter to pass the modulated light beam during an “on” state in synchronism with the motion picture so the subtitles are superimposed at desired times on desired portions of the motion picture and cause the shutter to attenuate the light beam during an “off” state.

Abstract: An apparatus for measuring the conductivity of an electrolyte comprises at least one conductivity cell, e.g., syringe-type conductivity cell and a constant temperature jacket. The syringe-type conductivity cell preferably employed in the apparatus comprises a generally longitudinal, cylindrical wall and two electrode rods which serve to define a volume for testing the conductivity of a sample in the volume. The constant temperature jacket comprises at least one longitudinal chamber for holding a conductivity cell, a temperature sensing device, and a fluid channel which is in fluid communication with a source of constant temperature fluid.