Abstract: A multimedia method and apparatus is able to digitally mix audio signals to produce combined audio output signals. Prior to digital mixing, the audio input signals are de-formatted using a digital de-formatter, volume adjusted using digital volume controllers and converted to a common sampling rate utilizing a digital interpolator or decimator.

Abstract: A sequential buffer device for connection to a serially readable memory. The device has an input for serially receiving successive data frames, which frames contain user data, error detection data and error correction data in a predetermined pattern; a random access memory which is connected to the input in order to store the data of at least one frame received in a byte-wise first write operation, under the control of a byte-wise incrementable address counter; a cyclically operational error detection device which is connected to the input in order to execute an error detection on the basis of the error detection data in a frame received; an error correction device which is bidirectionally connected to the random access memory in order to localize and correct an error under the control of the error correction device and on the basis of the error correction data in the frame; and a first-in-first-out (FIFO) memory having a capacity which equals at the most the capacity of the random access memory.

Abstract: An image is scanned by a TV camera 9 and the resultant signal digitized in an analogue to digital converter 12 the output of which represents the measured intensity of each picture element of the image. The values relating to selected lines may be captured in a line store 13. Alternatively the number of picture elements of a selected intensity may be counted during the count of a scan in a level counter 14, using a look-up table 15 as a mask to select the desired level. After all levels have been similarly counted the resultant histogram is modified by mapping each intensity into a new value with a smaller number of bits in such a way as to tend to equalize the number of picture elements in each new level. The new values are loaded into the look-up table 15 and in subsequent scans the measured intensities are converted into the new values, which may be displayed on a monitor 16 or captured in the line store 13.