摘要:
For synchronising the operation of first and second video devices referenced by respective timecodes and operable at different video rates in response to first and second timing references where the first video rate is a m/n times the second video rate, a predetermined phase relationship is established between the first timecodes from the first video device and second reference signals for the second video device and then target timecodes for synchronising the second video device are derived from the first timecodes and the second reference signals. In a first embodiment second timing reference signals are generated with a fixed, repeatable phase relationship with respect to the first timecodes by resetting the timing of the second timing reference signals in response to a first timecode which, when divided by m, gives a predetermined remainder. In a second embodiment a phase relationship between internally generated first and second reference signals is determined and then the first video device is synchronised with the first reference signals.
摘要:
A time base changer for a video converter for converting between a sequence of input video images at an input video rate and a sequence of output video images at an output video rate is operable to convert from one of a number of input video rates to an output video rate. The time base changer includes N video stores 32 where N is a integer greater than one, each for storing a video image. The video stores are enabled cyclically and at the appropriate input video rate for storing successive input video images in successive video stores. Multiplexers 36 connected to the video stores can output pairs of video images from the video stores at the output video rate. The time base changer includes a counter 38 which can be clocked at the appropriate one of the input video rates. The counter is preferably a modulo-N counter. Control signals for controlling the multiplexer in the selection of the adjacent pairs of video stores preferably includes a samplers 44 for sampling the output of the counter 38 at the output video rate.
摘要:
Data formatting apparatus for formatting variable bit length data words into successive fixed bit length data words comprises an N-bit circular buffer comprising a plurality of concatenated buffer sections, each buffer section having the same bit length as one of the fixed bit length data words. A modulo-N counter generates a count of the cumulative length of received variable bit length data words. Each received variable bit length data word is stored in the N-bit circular buffer at a bit position dependent on the count signal, and, in response to a detection that data has been stored in all of the bits of that buffer section, the stored data from that buffer section is output as a fixed bit length data word.
摘要:
A serial data decoder is described employing a bank of parallel primary Huffman decoders 70 each operating to decode a stream of variable length code words with embedded control code words into a stream of fixed length index values. The fixed length index values are fed to a secondary decoder which operates under control of the fixed length index values representing control code words to decode the fixed length index values representing the variable length code words into output data.
摘要:
A method of operating a receiver, comprising: determining a location of the receiver by analyzing a broadcast signal received by the receiver, determining information for a user, the information being dependent on the determined location, and presenting the information to the user.
摘要:
Image processing apparatus is described in which a source stream of data captured by a particular source is passed through a data splitter where it is split using one splitting technique into a plurality of split streams of data. These split streams of data each contain only part of the information within the source stream of data. The split streams of data are separately manipulated by a post production unit prior to being passed through a data combiner where they are recombined to form an output stream of data. The source stream of data and the output stream of data are of a higher resolution than the individual split streams of data. The post production unit includes at least one reformatter for reformatting the data stream to use a different splitting technique matched to the manipulation being performed in the post production unit.
摘要:
In order to reduce the effects of discontinuities at the edge of a picture and reduce erosion of the usable picture area caused by a filtering or interpolation operation, the edges of the picture are extrapolated prior to such an operation. This may be achieved by a circuit which receives an input line of active pixel data; forms from the input line a delayed line of the active pixel data; produces at least one additional start pixel data derived from a pixel data at or adjacent the start of the input line; produces at least one additional end pixel data derived from a pixel data at or adjacent the end of the input line; and forms an output sequence of pixel data by selecting for the output sequence the additional start pixel data, then at least part of the delayed line, and then the additional end pixel data. This circuit therefore performs zero-order (repeat) extrapolation at the beginning and end of each line. Other circuits are also described for extrapolating lines at or adjacent the start and end of each frame, and for performing a first- or higher-order extrapolation.
摘要:
In a method of converting a 60 field/s 2:1 interlaced video signal to 24 frame/s film, for each sequence of five input fields: the fields of at least one pair of the input fields are each progressive scan converted to form a pair of frames, and a weighted addition of the frames is made on a pixel-by-pixel basis to form an output video frame with a shifted temporal centroid, so that the temporal centroids of the output video frames are equally spaced. The output video frames are then recorded on film. In another method, the progressive scan conversion and weighted addition is performed by a single filter.
摘要:
A data decoder is described for decoding interleaved first type code words [RUNLENGTH, SIZE] and second type code words [AMPLITUDE], each first type code word serving to define a runlength of constant values preceding a variable value defined by a following second type code word. The first type code words and the second type code words are fed to respective first and second pipeline delay units 22 and 24. The output from the first pipeline delay unit 22 is fed to a state machine 26 which reads the RUNLENGTH value and generates an INSERT ZEROS signal for a period proportional to the RUNLENGTH value followed by a signal triggering reading of the second pipeline delay unit 24. The INSERT ZEROS signal and the output of the second pipeline delay unit 24 are fed to a multiplexer 28 which selects between them to generate the appropriate OUTPUT signal. A swing buffer 10 is disposed upstream of the first and second pipeline delay units 22 and 24. The second pipeline delay unit 24 is also used to effect fixed length code decoding.
摘要:
In order to simulate, on set or on location, a subsequent video to film conversion process, an input interlaced video signal is converted in any of a variety of ways to a progressive scan format video signal, and then interlaced fields of the progressive scan format frames are displayed on a video monitor or view finder.