CN101742318B - Device and method for video decoding and deblocking - Google Patents

Abstract

The invention provides a video decoding and deblocking device which is used for decoding and deblocking a plurality of macro blocks of a video frame. The video decoding deblocking device includes: a decoder for decoding each macro block; a deblocking buffer, comprising a plurality of counters, wherein the counters respectively correspond to one of the macro block groups, and when a macro block of one of the macro block groups is decoded, the counter corresponding to the macro block group is incremented by one; and a deblocking filter for deblocking all macro blocks of the macro block set when the counter corresponding to the macro block set counts to a predetermined value.

Description

Device and method for video decoding and deblocking

technical field

The present invention relates to a video decoding and deblocking device and method, and more particularly to a video decoding and deblocking device and method for reducing buffer space.

Background technique

The purpose of video coding technology is to solve the problem of excessively large video files. It compresses video to reduce storage space, reduce transmission burden, and control the degree of distortion of image quality within an acceptable range.

Many video standards use blocks as the basis for codecs. Take H.264/AVC (Advanced Video Coding), the most popular video coding technology at present, as an example. This technology divides a video frame (video frame) into multiple macroblocks (macroblock) in units of 16×16 pixels. . During block coding, in order to reduce the amount of data, the original pixel values of video frames are often replaced by approximate values. However, after the video frame is decoded, the pixel values between two adjacent macroblocks are usually too different to make the picture unnatural. Therefore, the video frame must be deblocked again, so as to reduce the pixel value difference between two adjacent macroblocks and improve the picture quality.

FIG. 1 is a schematic diagram of two adjacent macroblocks. The macroblock 10 and the macroblock 20 respectively include a plurality of pixels (wherein the macroblock 10 only takes the pixel P1 as an example, and the macroblock 20 only takes the pixel P2 as an example), when performing deblocking processing, for example, Two adjacent pixels P1 and P2 belonging to different macroblocks can be interpolated to achieve the effect of softening the boundary.

FIG. 2 is a video frame 200 having 256x64 pixels. The video frame 200 is divided into 16×4 macroblocks in units of 16×16 pixels, namely macroblocks MB(0,0), MB(0,1)˜MB(3,15). If the video decoder uses a macroblock as a unit and decodes in block order, when the two macroblocks MB(0,0) and MB(0,1) are decoded, the two macroblocks MB(0,0) ), the boundary C(0, 1) between MB(0, 1) can be deblocked; when the macroblock MB(0, 0) of the first row and the macroblock MB(1, 0) is decoded, the boundary R(0,1) between the two macroblocks MB(0,0) and MB(1,0) can be deblocked, and so on.

However, in some cases, the video decoder does not decode in an order but in an arbitrary order, such as the Flexible Macroblock Ordering (FMO) mode and the Arbitrary Arrangement (Arbitrary) mode in the H.264/AVC standard. Slice Ordering, ASO) mode. However, in traditional video processing techniques, the deblocking process must still be performed sequentially. Therefore, in order to enable deblocking to cooperate with decoding, a deblocking buffer must be additionally configured in the known technology to record whether each macroblock has been decoded. FIG. 3 illustrates a deblocking buffer for processing the video frame 200 of FIG. 2 . The deblocking buffer 300 has 16×4 bits corresponding to the 16×4 macroblocks of the video frame 200 , and each bit records whether each macroblock has been decoded. In Fig. 3, for example, a bit marked as 1 indicates that the macroblock corresponding to the bit has been decoded, then it can be seen from the figure that the macroblocks MB (0, 0), MB (1, 12), MB (2, 0)...etc Decoding is complete.

In addition, when the resolution of the processed image is higher, a larger buffer space is required. For example, a full high-definition (Full HD) standard video frame has 1920×1080 pixels. In order to meet the needs of its deblocking processing, we need to configure a buffer space of 8160 bits, and its size is not small. Therefore, how to design a device and method that can reduce the buffer space is an important issue to be solved urgently.

Contents of the invention

The present invention provides a video decoding and deblocking device for decoding and deblocking multiple macroblocks (macroblocks) of a video frame, including: a decoder for decoding each macroblock; The deblocking buffer includes a plurality of counters, the plurality of counters are respectively corresponding to a macroblock group in the plurality of macroblock groups, wherein each macroblock group is composed of a plurality of adjacent macroblocks, when When a macroblock of a macroblock group in the plurality of macroblock groups is decoded, the counter corresponding to the macroblock group is incremented by one; and a deblocking filter is used for deblocking the macroblock When the counter corresponding to the group counts to a predetermined value, all macroblocks in the macroblock group corresponding to the counter are deblocked.

The present invention also provides a video decoding and deblocking method for decoding and deblocking multiple macroblocks of a video frame, including: decoding each macroblock; when multiple macroblocks When a macroblock of a macroblock group in the group is decoded, the counter corresponding to the macroblock group is increased by one, wherein each macroblock group is composed of a plurality of adjacent macroblocks; When the counter corresponding to the macroblock group counts to a predetermined value, all macroblocks in the macroblock group are deblocked.

Description of drawings

FIG. 1 is a schematic diagram of two adjacent macroblocks;

Fig. 2 is a video frame with 256 * 64 pixels;

Figure 3 is a deblocking buffer for processing the video frame of Figure 2;

4 is a schematic diagram of a video decoding and deblocking device and video frames processed therein according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of an embodiment of a counter and a video frame;

FIG. 6 is a flowchart of a video decoding and deblocking method according to an embodiment of the present invention.

[Description of main component labels]

10～macro block; 20～macro block;

P1～pixel; P2～pixel;

200～video frame; 300～deblocking buffer;

400～video decoding and deblocking device; 402～decoder;

404～deblocking buffer; 406～deblocking filter;

C00～C13～counter; S602～S610～step.

Detailed ways

The following describes the preferred embodiment of the present invention. Each embodiment is used to illustrate the principles of the present invention, but not to limit the present invention. The scope of the invention should be determined by the appended claims.

A preferred embodiment of the present invention is a video decoding and deblocking device 400, which is used for decoding and deblocking multiple macroblocks of a video frame. In other embodiments, the video frame may include A×B pixels, where A and B are positive integers, wherein the video frame is divided into C×D macroblocks, and each macroblock includes E×F pixels, Wherein A, B, C, D, E, F are positive integers, and satisfy A×B=C×D×E×F. To simplify the description, this embodiment takes a video frame with 256×64 pixels as an example, which is divided into 16×4 macroblocks with 16×16 pixels as a unit as described in the prior art, as shown in FIG. 4 .

FIG. 4 is a schematic diagram of a video decoding and deblocking device 400 and the processed video frame 200 according to an embodiment of the present invention. The video decoding and deblocking device 400 of the present invention includes a decoder 402 , a deblocking buffer 404 , and a deblocking filter 406 .

The decoder 402 of the present invention decodes the macroblocks in an arbitrary order, as shown in FIG. 4 . It should be noted that the arbitrary order here means a random or irregular order. Although the present invention can achieve better results when applied to arbitrary order decoding, the present invention is not limited thereto. Arbitrary order naturally covers the special case of fixed order in this paper, so in other embodiments, the decoder 402 of the present invention can also decode the macroblocks in order.

The deblocking buffer 404 of the present invention includes a plurality of counters. In one embodiment, every N×M adjacent macroblocks of a video frame may be taken as a macroblock group, and each counter of the deblocking buffer 404 is corresponding to each macroblock group. In order to simplify the description, in this embodiment, every 8 (N=8, M=1) adjacent macroblocks in the video frame are taken as a macroblock group, for example, macroblocks MB(0,0)～ MB(0,7) is the 00th macroblock group, macroblocks MB(1,0)-MB(1,7) are taken as the 01st macroblock group, and so on, as shown in FIG. 4 . In this embodiment, there are 8 counters C00˜C13 corresponding to the 00th macroblock group MBG00 to the 13th macroblock group MBG13 respectively. In the present invention, when no macroblock is decoded, the counter is zero; when a macroblock in a macroblock group is decoded, the counter corresponding to the macroblock group is increased by one; after that, If another macroblock in the macroblock group is decoded, the counter is incremented to two, and so on.

In one embodiment, the deblocking filter 406 of the present invention is used to deblock the macroblock groups in a predetermined order. When a counter counts to N×M, and all the macroblocks in the macroblock group whose deblocking sequence is before the macroblock group corresponding to the counter have been deblocked, the deblocking filter 406 corresponds to the counter All macroblocks of the macroblock group are deblocked. In this embodiment, taking the deblocking order from left to right and from top to bottom as an example, when a counter counts to 8, and the counter corresponds to the macroblock group above and to the left of the macroblock group When all the macroblocks have been deblocked, the deblocking filter 406 deblocks all the macroblocks in the macroblock group corresponding to the counter. See below for complete detailed examples of the invention.

FIG. 5 is a schematic diagram of an embodiment of a counter and a video frame. The video frame in Fig. 5 is the same as the video frame in Fig. 2 and Fig. 4, and each of the 00th macroblock group MBG00 to the 13th macroblock group MBG13 has a different number of macroblocks that have been decoded, respectively in Fig. are marked with a slash, such as macroblocks MB(0, 1), MB(3, 14), etc.; those that have not been decoded are not marked. In the embodiment of FIG. 5, the counters C00-C03, C10-C13 are respectively counted as 8, 3, 4, 7, 8, 6, 8 and 5 (indicated in brackets of each counter in the figure). Wherein, the counters C00 , C10 and C12 all count to 8, indicating that all the macroblocks in the macroblock groups MBG00 , MBG10 and MBG12 have been decoded. The deblocking filter 406 of the present invention can further deblock all macroblocks MB(0,0)˜MG(0,7) in the macroblock group MBG00. After the macroblock group MBG00 completes deblocking, since all macroblocks in the macroblock group MBG00 to the left of the macroblock group MBG10 have been deblocked, the deblocking filter 406 will continue to deblock the macroblock group MBG10 to deblock. However, since the macroblock groups MBG11 and MBG02 above and to the left of the macroblock group MBG12 have not yet completed deblocking, the deblocking filter 406 of the present invention does not perform deblocking operation on MBG12 temporarily.

It should be noted that each of the counters can be composed of k bits. In some embodiments, if every N×M adjacent macroblocks of the video frame are taken as a macroblock group, the counter can be There are k bits, where k satisfies 2 ^k ≥ (N×M)+1, and those skilled in the art can design it by themselves according to the present invention. Ideally, N×M is at least 2, but the present invention is not limited thereto. In the aforementioned embodiment, every 8 adjacent macroblocks in the video frame are taken as a macroblock group, and each counter only needs 4 bits (2 ⁴ ≥ 9). For the video frame 200 in Figure 4 and Figure 5, the buffer of the present invention only needs 32 bits, compared with the 64 bits of the buffer in Figure 3, it can save at least half of the buffer space, thereby improving the video codec s efficiency.

The present invention also provides a video decoding and deblocking method, and FIG. 6 is a flowchart of a video decoding and deblocking method according to an embodiment of the present invention. The video decoding and deblocking method of the present invention is used to decode and deblock multiple macroblocks of a video frame, comprising the following steps: in step S602, decoding each macroblock; in step S604, obtaining the video frame Each of N×M adjacent macroblocks is a macroblock group; in step S606, a plurality of counters are provided, and each of the counters is corresponding to each macroblock group. For the description of the counter, please refer to As mentioned above; in step S608, when a macroblock of a macroblock group is decoded, the counter corresponding to the macroblock group is increased by one; in step S610, when the macroblock group corresponds to The counter counts to N×M, and when all the macroblocks of the macroblock group before the macroblock group have been deblocked, all the macroblocks of the macroblock group are deblocked piece.

In the above video decoding and deblocking method, the video frame may include A×B pixels, where A and B are positive integers, wherein the video frame is divided into C×D macroblocks, and each macroblock includes E×F pixels, where A, B, C, D, E, F are positive integers, and satisfy A×B=C×D×E×F. Generally speaking, the video frame can be divided into units of 16×16 pixels according to the prior art. In addition, the above N×M is at least 2, but the present invention is not limited thereto.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention should be defined by the appended claims.

Claims (10)

1. A video decoding and deblocking device, used to decode and deblock a plurality of macroblocks of a video frame, comprising: a decoder for decoding each of the macroblocks in an arbitrary order; A deblocking buffer, including a plurality of counters, the plurality of counters are respectively corresponding to a macroblock group in the plurality of macroblock groups and respectively represent the decoding status of the macroblocks in the plurality of macroblock groups, wherein Each macroblock group is composed of a plurality of adjacent macroblocks. When a macroblock of a macroblock group in the plurality of macroblock groups is decoded, the macroblock group Correspondingly, the counter is incremented by one; and a deblocking filter, used for when the counter corresponding to the macroblock group counts to a predetermined value, and all the macroblocks of the adjacent macroblock group whose deblocking order is before the macroblock group have been When deblocking is complete, all macroblocks of the macroblock group are deblocked. 2. The video decoding and deblocking device according to claim 1, wherein each macroblock group of the plurality of macroblock groups is composed of every N×M adjacent macroblocks of the video frame; The counter includes k bits, and k satisfies 2 ^k ≥ (N×M)+1; the predetermined value is N×M, and N×M is at least 2. 3. The video decoding and deblocking device according to claim 1, wherein the deblocking filter deblocks the plurality of macroblock groups according to a predetermined order. 4. The video decoding and deblocking device according to claim 1, wherein the video frame comprises A×B pixels, the video frame comprises C×D macroblocks, and each macroblock comprises E×F pixels , where A, B, C, D, E, F are positive integers and satisfy A×B=C×D×E×F. 5. The video decoding and deblocking device according to claim 1, wherein the decoder performs decoding according to the H.264/AVC standard. 6. A video decoding and deblocking method for decoding and deblocking a plurality of macroblocks of a video frame, comprising: decoding each of the macroblocks in an arbitrary order; When a macroblock of a macroblock group in a plurality of macroblock groups is decoded, a counter corresponding to the macroblock group is increased by one, and the plurality of counters respectively represent the plurality of macroblocks The decoding situation of the macroblocks in the group, wherein each macroblock group is composed of a plurality of adjacent macroblocks; When the counter corresponding to the macroblock group counts to a predetermined value, and all the macroblocks in the adjacent macroblock group before the macroblock group have been deblocked, the macroblock All macroblocks of a block group are deblocked. 7. The video decoding and deblocking method according to claim 6, wherein each macroblock group of the plurality of macroblock groups is composed of every N×M adjacent macroblocks of the video frame; the The counter includes k bits, and k satisfies 2 ^k ≥ (N×M)+1; the predetermined value is N×M, and N×M is at least 2. 8. The video decoding and deblocking method according to claim 6, comprising deblocking the plurality of macroblock groups according to a predetermined order. 9. The video decoding and deblocking method according to claim 6, wherein the video frame comprises A×B pixels, the video frame comprises C×D macroblocks, and each macroblock comprises E×F pixels , where A, B, C, D, E, F are positive integers and satisfy A×B=C×D×E×F. 10. The video decoding and deblocking method according to claim 6, wherein the decoder performs decoding according to the H.264/AVC standard.