Circuit for synchronizing picture and method therefor
AssigneeSamsung Electronics Co., Ltd.
InventorSeong-bong Kim
Life of this patent
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Abstract
A picture decoding synchronizing circuit and a picture decoding synchronizing method are provided. When the decoding synchronization is controlled in units of a picture, in a variable length decoder using the transferred PTS and DTS information, the value obtained by adding the previous DTS to an offset is determined to be the DTS value of the current picture, if errors are generated in the transferred PTS and DTS, considering the errors of the transferred bit stream. If no errors are generated in the PTS or DTS, then the transferred PTS and DTS are determined to be the DTS value of the current picture. By controlling the picture decoding using the determined DTS value, the bit buffer does not underflow or overflow and the decoded data is displayed naturally on a screen.
Claims21
A picture decoding synchronizing circuit, comprising:
- a detector for detecting whether at least one of a presentation time stamp (PTS) and a decoding time stamp (DTS) which are transferred through an input bit stream is distorted by an error, and outputting a detect signal;
- a determiner for determining an actual DTS value using a transferred PTS and DTS if no errors are detected from the transferred PTS and DTS according to the detect signal, and determining an approximated DTS value using the value obtained by adding a DTS value of a previous picture to a predetermined offset value, if an error is detected in at least one of said PTS and said DTS;
- and
- a decoder for decoding the input bit stream in units of a picture, in synchronization with one of the actual DTS value and the approximated DTS value.
A picture decoding synchronizing circuit, comprising:
- an extractor for extracting a video elementary stream, a presentation time stamp (PTS), a decoding time stamp (DTS), and a system time clock (STC) from a transferred bit stream;
- a buffer for temporarily storing the video elementary stream;
- a variable length decoder for controlling the decoding of the video elementary stream stored in the buffer so that the buffer does not overflow or underflow, parsing a header of the video elementary stream, and outputting temporal reference information, a picture structure signal, a GOP header detect signal, a picture header detect signal, and a picture type signal;
- and
- a decoding controller for determining whether an error is generated in at least one of the DTS and the PTS and generating control signals for controlling the decoding using a determined DTS value by adding a DTS of a previous picture to an offset value, if an error is generated in at least one of the DTS and the PTS.
A picture decoding synchronizing method, comprising the steps of:
- (a) determining whether at least one of a presentation time stamp (PTS) and a decoding time stamp (DTS), transferred through an input bit stream, are distorted;
- (b) determining an actual DTS value using a transferred PTS and the DTS if no errors are detected in the transferred PTS and DTS, according to a detect signal, and otherwise, determining an approximated DTS value by adding a DTS value of a previous picture to an offset value;
- and
- (c) decoding the input bit stream in units of a picture, in synchronization with at least one of the actual DTS value and the approximated DTS value.
A picture decoding synchronizing method, comprising the steps of:
- (a) extracting a video elementary stream, a presentation time stamp (PTS), a decoding time stamp (DTS), and a system time clock (STC);
- (b) controlling the decoding of the video elementary stream, parsing the header of the video elementary stream, and detecting temporal reference information, a picture structure signal, a GOP header detect signal, a picture header detect signal, and a picture type signal;
- and
- (c) determining whether an error is generated in at least one of the DTS and the PTS, and when an error is generated, generating control signals for controlling the decoding using a DTS value determined by adding a DTS of a previous picture to an offset value.
Dependencies are inferred from the claim text.