Image processing using shared frame memory
When a reverse reproduction is instructed, an MPEG video stream is once decoded and is again recoded by an MPEG video encoder so as to generate a recoded data sequence which will be overwritten on a storage area in a hard disk. An MPEG video decoder reads out this recoded data sequence in a reverse time-series manner and decodes it successively, and then converts it to a video signal so as to be outputted to a display.
1. An image processing apparatus, comprising:
a front-end decoder which generates a first reproduced image data sequence by decoding a first coded data sequence including I picture, P picture and B picture coded in compliance with MPEG;
a first frame memory, utilized for a decoding processing by said front-end decoder, which stores the first reproduced image data sequence;
an encoder which generates a second coded data sequence by recoding the first reproduced image data sequence read out from said first frame memory;
a back-end decoder which generates a second reproduced image data sequence by decoding the second coded data sequence; and
a second frame memory, utilized for a decoding processing by said back-end decoder, which stores at least one picture included in the second reproduced image data sequence,
said first frame memory, including:
a first region which stores at least one I picture or one P picture to be front referred to for decoding P pictures or B pictures;
a second region which stores at least one I picture or one P picture to be back referred to for decoding B pictures; and
a third region, utilized for a decoding processing by said front-end decoder, which stores at least one B picture.
2. An image processing apparatus according to claim 1 , wherein processings for the decoding and the recoding are carried out in a predetermined unit of group.
3. An image processing apparatus according to claim 1 , wherein said first frame memory and second frame memory include a memory capacity equivalent to at least four frames in total.
4. A television receiver equipped with an image processing apparatus according to claim 1 , whereby reproduction of images in a reverse time-series manner is included as part of operational specifications thereof.