VIDEO DECODED PICTURE BUFFER

• US 20080002773A1
• Filed: 06/21/2007
• Published: 01/03/2008
• Est. Priority Date: 06/26/2006
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Lai, Wai-Ming
• Application Number:
  US11/766,250
• Publication Number:
  US 20080002773A1
• Time in Patent Office: Days
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

The H.264/AVC decoded picture buffer is managed with an additional display queue list and a free buffer list together with the decoded picture buffer determined by pointers to frame buffers to limit frame copying.

Claims

1. A method of decoding of video having motion compensation with multiple reference pictures, comprising the steps of:

(a) providing a plurality of frame buffers;

(b) providing a decoded picture buffer (DPB) as a subplurality of said plurality of frame buffers, where reference frames needed for decoding are kept in said DPB;

(c) providing a display queue list (DQ) of output frames of said DPB, where a frame is kept in said DQ until it is sent for display and where a frame in said DQ prevents said DPB access to the corresponding frame buffer;

(d) providing a list of free frame buffers, where a frame buffer with a frame which is no longer needed for reference or display is put in the list of free frame buffers and is available for said DPB;

(e) decoding an input frame; and

(f) when said decoded input frame is a reference frame, storing said decoded input frame in said DPB, where after said DPB outputs a frame to said DQ, said DQ and said free frame buffer list are updated; and

(g) repeating steps (e)-(f) with said input frame replaced by subsequent frames.

2. The method of claim 1, wherein when a frame output from said DPB to said DQ is a non-reference frame, the corresponding frame buffer in said DPB is replaced by a free frame buffer.

3. The method of claim 1, wherein when a frame output from said DPB to said DQ is a reference frame and when said a frame changes from a reference frame to a non-reference frame prior to display, the corresponding frame buffer in said DPB is replaced by a free frame buffer.

4. The method of claim 1, wherein when a frame output from said DPB to said DQ is a reference frame and when said a frame changes from a reference frame to a non-reference frame after display, the corresponding frame buffer in said DPB becomes a free frame buffer.

5. A decoder for decoding video having motion compensation with multiple reference pictures, comprising:

(a) N+3 frame buffers where N is the number of references frames for a decoded picture buffer (DPB);

(b) a processor coupled to said frame buffers, said processor operable to;

(i) store a reference frame needed for decoding in said DPB;

(ii) provide a display queue list (DQ) of output frames of said DPB, where a frame is kept in said DQ until it is sent for display and where a frame in said DQ prevents said DPB access to the corresponding frame buffer;

(iii) provide a list of free frame buffers, where a frame buffer with a frame which is no longer a reference frame or needed for display is put in the list of free frame buffers and is available for said DPB;

(iv) decode an input frame using one of said frame buffers and said DPB; and

(v) when said decoded input frame is to be stored in said DPB, update said DPB output frames in said DQ and said free frame buffer list;

(c) wherein said DPB is determined by N pointers to N of said N+3 frame buffers.