Picture decoding and display unit including a memory having reduce storage capacity for storing pixel data
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsAkihiko Takabatake, Shinichi Uramoto
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Abstract
A memory having a storage capacity of storing pixel data of one frame is employed as a bank for display of bidirectional predictive encoded pixel data, and time difference between a timing for starting decoding of a given frame in a decoding unit and that for starting display of pixel data of the given frame in a display unit is set at one field time. The storage capacity of a memory device employed for display of pixel data is reduced in a picture decoding and display unit having a decoding and display function.
Claims12
A picture decoding and display unit for decoding predictively encoded pixel data of a picture included in a supplied bit stream, restoring original pixel data for outputting to a display unit for display thereon, said picture being formed by pixel data of a frame having two fields, said picture decoding and display unit comprising:
- decoding means coupled to receive said bit stream, for extracting said pixel data included in said bit stream and carrying out a decoding processing on the extracted pixel data to restore said original pixel data, said decoding means including means for extracting information indicating whether a type of said frame of the supplied pixel data included in said bit stream is an I/P picture employed as a reference picture in the decoding processing of a B picture not employed as the reference picture but subjected to only display, for identifying the type of said frame;
- memory means coupled to said decoding means for storing the pixel data of said B picture restored by said decoding means in accordance with a B picture identification indication signal from said decoding means;
- read means coupled to said memory means for reading the pixel data stored in said memory means and outputting the read out pixel data to said display unit for display;
- and
- control means coupled to said decoding means and said read means for controlling operation timings of said decoding means and said read means such that time difference between a timing for starting said decoding processing of a B picture and that for outputting the restored pixel data of said B picture from said memory means to said display unit through said read means is substantially one field time required for outputting one field pixel data of said B picture to said display unit, said control means including means for starting a decoding operation of a first field of a subsequent frame in response to starting of reading of pixel data of the last field of a decoded and stored frame to the display unit.
The picture decoding and display unit for decoding predictively encoded pixel data of a picture included in an incoming bit stream, restoring original pixel data and outputting the restored original pixel data for display on a display unit, said picture formed by a frame of a plurality of fields, said picture decoding and display unit comprising:
- decoding means coupled to receive said bit stream, for carrying out a decoding processing on said predictively encoded pixel data to restore said original pixel data;
- storage means coupled to said decoding means, for storing said restored pixel data received from said decoding means;
- read means coupled to said storage means, for reading pixel data from said storage means for outputting said display unit for display thereon;
- control means coupled to said read means and said decoding means for making said decoding means start decoding processing of pixel data of a frame supplied subsequently to a certain frame including a last field to be finally displayed in the certain frame in response to reading of said last field from said read means, said picture being different from a picture comprised of said certain frame;
- wherein types of said frame of said picture include an I/P picture employed as a reference picture in the decoding processing and a B picture not employed as the reference picture but subjected to only display, said storage means includes a frame memory storing pixel data of one frame as a storage element for storing only said B picture pixel data.
A picture decoding and display unit for decoding predictively encoded pixel data of a picture included in a supplied bit stream, restoring original pixel data for outputting to a display unit for display thereon, said picture formed by a frame of two fields, said picture decoding and display unit comprising:
- decoding means coupled to receive the bit stream, for carrying out a decoding processing on said predictively encoded pixel data in the received bit stream to restore said original pixel data;
- storage means coupled to said decoding means, for storing the restored pixel data received from said decoding means;
- read means coupled to said storage means, for reading said pixel data from said storage means for outputting to said display unit for display thereon;
- and
- control means coupled to said read means and said decoding means for starting reading of pixel data of a first field of a frame to be displayed with a time difference required for reading pixel data of one field from said storage means in response to starting of the decoding processing on the first field in said decoding means;
- said control means includes means for starting a decoding operation of a first field of a subsequent frame in response to starting of reading of pixel data of a last field of the decoded and stored frame to the display unit.
Dependencies are inferred from the claim text.