TW201711477A - Video encoding methods and systems using adaptive color transform - Google Patents

Abstract

A video encoding method including the following step is provided. A source video frame is received. The source video frame is divided into a coding tree unit. A coding unit is determined from the coding tree unit. A coding mode of the coding unit is enabled or disabled. If the coding mode is enabled, whether to evaluate a size of a transform unit for the enabled coding mode is determined. A transform unit of the coding unit for the enabled coding mode is determined. The size of the coding unit is defined by a number (N) of samples.

Description

Video coding method and system using adaptive color conversion

The disclosure relates to a video encoding and decoding method and system.

The demand for high quality images is gradually increasing. With the advent of video formats such as 4K and 8K, it is highly desirable to improve video encoding and decoding efficiency. In addition, consumers expect to be able to transmit and receive high quality images through a variety of transmission media. For example, consumers want to be able to view high-quality images on portable devices (such as smart phones, tablets, laptops) and home TVs and computers over the Internet. Consumers also want to be able to display high-quality images during video conferencing and screen sharing.

High Efficiency Video Coding (HEVC) H.265 provides a new standard for improving the encoding and decoding performance of video compression. Compared with the original AVC (Advanced Video Coding) standard, it is established by ISO/IEC JTC 1/SC 29/WG 11 MPEG (Moving Picture Experts Group) and ITU-T SG16 VCEG (Video Coding Experts Group). HEVC can reduce the data rate of compressed high quality video. The AVC standard is also known as H.264.

HEVC compresses video using various coding tools such as inter prediction and intra prediction. Inter-frame prediction techniques use temporal redundancies between different video frames of a video stream to compress video material. For example, an encoded and decoded video frame containing similar content can be used to encode the current video frame. These encoded and decoded video pictures can be used to predict the coding area of the current video picture. In contrast, intra prediction techniques only compress the video data using the internal data of the currently encoded video frame. Intra prediction techniques do not use temporal redundancy of different video frames. For example, current video pictures are encoded using another part of the same picture. Intra prediction techniques include 35 intra modes, including Planar mode, DC mode, and 33 directional modes.

Compared to the AVC standard, the HEVC standard employs expansive partitioning and dividing for each input video picture. The AVC standard uses only macroblocks of input video pictures for encoding and decoding. Conversely, the HEVC standard can divide the input video frames into different sizes of data units and blocks, as described later. Compared to the AVC standard, the HEVC standard provides more flexibility for encoding, decoding, and decoding of dynamic, multi-detail and multi-edge video images.

Some coding tools that improve the video coding process are also included in the HEVC standard. Such coding tools are called coding extensions. The Screen Content Coding extension (SCC extension) focuses on improving the processing performance of video content under the HEVC standard. The screen content is the video that is rendered by the pattern, text, or animation, not the video scene captured by the camera. The imaged pattern, text or animation can be dynamic or static and can be provided for video within the video scene captured by the camera. Application examples of the SCC may include screen mirroring, cloud gaming, wireless display of content, displays generated during remote computer desktop access, and screens. Screen sharing (for example, instant screen sharing of video conferencing).

One of the coding tools in the SCC is an adaptive color transform (ACT). The ACT is a color space conversion applied to a residual pixel sample of a coding unit (CU). For a particular color space, there is already a correlation of the color components of one of the coding units (CU). When the correlation of the color elements of the pixels is high, performing ACT on the pixels can help the related color elements to concentrate energy through de-correlating. This concentrated energy approach can increase coding efficiency and reduce coding costs. Therefore, ACT can improve coding efficiency in the HEVC encoding process.

However, in the encoding process, an additional rate distortion optimization (RDO) is needed to evaluate whether ACT is enabled. RDO is used to estimate the cost of rate distortion (RD). These assessment processes may Will increase the coding complexity and coding time. Furthermore, ACT may not be necessary when the color elements of the pixels have been correlated. In this case, since the cost of executing the ACT is higher than the benefit of the encoding, further de-correlation procedures for color elements may not bring any benefit.

According to an aspect of the disclosure, a video encoding method is provided. The video encoding method includes the following steps. Receive a source video frame. The original video picture is divided into a coding tree unit. A coding unit is determined from the coding tree unit. Enable or disable one of the coding units' coding modes. If the encoding mode is enabled, the encoding mode is enabled to determine whether to estimate the size of a transform unit. The coding mode enabled determines the conversion unit of the coding unit. The size of the coding unit is NxN.

According to another aspect of the present disclosure, a video encoding system is provided. The video coding system includes a memory and a processor. Memory is used to store a set of instructions. The processor is configured to execute the set of instructions. This set of instructions includes the following steps. Receive a source video frame. The original video picture is divided into a coding tree unit. A coding unit is determined from the coding tree unit. Enable or disable one of the coding units' coding modes. If the encoding mode is enabled, it is determined in the enabled encoding mode whether to estimate the size of a transform unit. The coding mode is enabled to determine the rotation of the coding unit Change the unit. The size of the coding unit is NxN.

According to another aspect of the present disclosure, a non-transitory computer readable recording medium is provided. A non-transitory computer can read a recording medium for storing a set of instructions. The set of instructions is executed by one or more processors to perform a video encoding method. This video encoding method includes the following steps. Receive a source video frame. The original video picture is divided into a coding tree unit. A coding unit is determined from the coding tree unit. Enable or disable one of the coding units' coding modes. If the encoding mode is enabled, it is determined in the enabled encoding mode whether to estimate the size of a transform unit. The coding mode enabled determines the conversion unit of the coding unit. The size of the coding unit is NxN.

In order to better understand the above and other aspects of the present disclosure, various embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

101‧‧‧Video video (video frame)

102‧‧‧coding tree unit (CTU)

103‧‧‧Luma coding tree block (luma CTB)

104‧‧‧Cb CTB

105‧‧‧Cr CTB

106, 111‧‧‧Related notes

107-1, 107-2, 107-3, 107-4‧‧‧ luma coding block (luma CB)

108‧‧‧Coding unit (CU)

109‧‧‧Cb CB

110‧‧‧Cr CB

112‧‧‧Luma prediction block (PB)

113-1, 113-2, 113-3, 113-4‧‧‧transform block (TB)

114‧‧‧Transformation unit (TU)

200‧‧‧Video Encoder

202‧‧‧Frame Dividing Module

204‧‧‧Inter Prediction enabling adaptive color transformation Module

206‧‧‧Inter Prediction disabling ACT Module

208‧‧‧ Frame Buffer

210‧‧‧Mode Decision Module

212‧‧‧Intra Prediction enabling ACT Module

214‧‧‧Intra Prediction disabling ACT Module

216, 218‧‧‧Summing Module

220‧‧‧Switch

222‧‧‧Adaptive Color Conversion (ACT) Module

224‧‧‧CCP, Conversion and Quantization Module (CCP, Transform, and Quantization Module)

226‧‧‧Entropy Coding Module

228‧‧‧Inverse CCP, Transform, and Quantization Module

230‧‧‧Switch

232‧‧‧Inverse ACT Module

300, 400, 500, 600, 700, 800‧‧‧ encoding methods

304‧‧‧Component correlation analysis

306‧‧‧ Rough mode decision

End of 308‧‧

310‧‧‧rate distortion optimization mode decision (RDO mode decision)

311‧‧‧ Whether the chroma format is judged by non-444 (non-444)

312‧‧‧Determination of whether the CU size is greater than the critical value T1

314‧‧‧TU size decision (TU size ecision)

316‧‧‧chroma mode decision

Whether the size of the 402‧‧‧ CU is less than the critical value T2

702‧‧‧ Non-transitory computer readable media

704‧‧‧ processor

Figures 1A-1J illustrate video screens and related segments in accordance with several embodiments of the present disclosure.

Figure 2 illustrates the video encoder of the present disclosure.

Figure 3 illustrates an encoding method in accordance with an embodiment of the present disclosure.

Figure 4 illustrates an encoding method in accordance with another embodiment of the present disclosure.

Figure 5 illustrates an encoding method in accordance with another embodiment of the present disclosure.

Figure 6 illustrates an encoding method in accordance with another embodiment of the present disclosure.

Figure 7 illustrates the flow of the IPM in a non-444 chroma format.

Figure 8 illustrates a system for performing the encoding and decoding methods of the present disclosure.

The exemplary embodiments will be described in detail below with reference to the accompanying drawings. In the drawings described below, the same reference numerals are used to refer to the same or the The embodiments presented below are not representative of all implementations of the present disclosure. In fact, these embodiments are merely some examples of systems and methods that correspond to the scope of the patent application.

1A-1J illustrate a video screen and its associated segmentation in accordance with an embodiment of the present disclosure.

FIG. 1A illustrates a video screen 101. The video screen 101 includes a number of pixels. The video screen 101 is divided into a number of coding tree units (CTUs) 102. The size of each CTU 102 is determined based on L vertical samples and L horizontal samples (LxL). Each sample corresponds to a pixel value at a different pixel location of the CTU. For example, L can be 16, 32, or 64. The pixel position can be the position where the pixel is located or the position between the pixels. When the pixel position is the position between the pixels, the pixel value may be an interpolation value of one or more pixels near the pixel position. Each CTU 102 includes a luma coding tree block (luma CTB), a chroma coding tree block (chroma CTB), and an associated syntax.

FIG. 1B illustrates that several CTBs can be included in one CTU 102 of FIG. 1A. For example, CTU 102 can include luminance CTB (luma CTB) 103, chroma CTB (chroma CTB) (including Cb CTB 104 Cr CTB 105). The CTU 102 may also include an associated syntax 106. Cb CTB 104 is a blue difference chroma component CTB, which indicates a change in CTB in blue. Cr CTB 105 is a red difference chroma component CTB, which indicates a change in CTB in red. The related description 106 includes information on how the luminance CTB 103, Cb CTB 104, and Cr CTB 105 are encoded, and further segmentation of the luminance CTB 103, Cb CTB 104, and Cr CTB 105. The CTB 103, Cb CTB 104, and Cr CTB 105 may be the same size as the CTU 102. Alternatively, the brightness CTB 103 may be the same size as the CTU 102, but the Cb CTB 104 and Cr CTB 105 may be smaller than the CTU 102.

Intra prediction, inter prediction, and other coding tools operate on coding blocks (CBs). To determine whether the coded program is to use intra prediction or inter prediction, the CTB can be partitioned into one or more CBs. The program for dividing CTB into CB is based on quad-tree partitioning. Therefore, the CTB can be divided into four CBs, and each CB can be further divided into four CBs. According to the size of the CTB, such a division procedure can be continued.

1C shows that the luminance CTB 103 of FIG. 1B is divided into one or more luminances CB 107-1, 107-2, 107-3 or 107-4. CTB with a brightness of 64x64 For example, the corresponding brightness CB 107-1, 107-2, 107-3 or 107-4 may be the size of NxN, for example 64x64, 32x32, 16x16 or 8x8. In the 1Cth picture, the size of the luminance CTB 103 is 64x64. The brightness CTB 103 can be 32x32 or 16x16 in size.

FIG. 1D illustrates an example in which the luminance CTB 103 of FIG. 1B performs quadtree partitioning, in which the luminance CTB 103 is divided into luminances CB 107-1, 107-2, 107-3, or 107-4 of the 1Cth graph. In the 1D diagram, the size of the luminance CTB 103 is 64x64. However, the brightness CTB 103 may also be 32x32 or 16x16 in size.

In the 1D picture, the luminance CTB 103 is divided into four 32x32 luminances CB 107-2. The brightness CB of each 32x32 can be further divided into four 16x16 brightness CB 107-3. The brightness CB of each 16x16 can be further divided into four 8x8 brightness CB 107-4.

A coding unit (CU) is used to encode the CB. The CTB can include a single CU or be divided into several CUs. Therefore, the size of the CU can also be NxN, for example 64x64, 32x32, 16x16 or 8x8. Each CU includes a luminance CB, two chrominance CBs, and related descriptions. The size of the residual CU generated in the encoding and decoding process may be the same as the size of its corresponding CU.

FIG. 1E is a schematic diagram showing CB (brightness CB 107-1 of FIG. 1C), and such CBs may be part of CU 108. For example, CU 108 may include luminance CB 107-1 and chrominance CB (Cb CB 109) and chrominance CB (Cr CB 110). The CU 108 can include a related description 111. Related Description 111 contains information on how to encode luminances CB 107-1, Cb CB 109, and Cr CB 110, such as It is the description of the quadtree information (the size, position and further division of the luminance CB and the chrominance CB). Each CU 108 may have associated prediction blocks (PBs) at luminances CB 107-1, Cb CB 109, and Cr CB 110. The prediction blocks are combined into prediction units (PUs).

FIG. 1F illustrates various possible cases in which the CB 107-1 of the 1D map is divided into the luminance PB 112. The luminance CB 107-1 is divided into the luminance PB 112, for example, according to the predictability of different regions of the luminance CB 107-1. For example, the brightness CB 107-1 may include a single brightness PB 112 that is the same size as the brightness CB 107-1. Alternatively, the luminance CB 107-1 may be vertically or horizontally divided into two even luminances PB 112. Alternatively, the luminance CB 107-1 may be divided into four luminances PB 112 vertically or horizontally. It should be noted that the 1Fth drawing is merely an example. Any manner of segmentation into PB under the HEVC standard is within the scope of the present disclosure. The manner in which the luminance CB 107-1 is divided into the luminance PB 112 as shown in FIG. 1F is mutually exclusive. For example, in the intra prediction mode of HEVC, 64x64, 32x32, and 16x16 CBs may be split into a single PB, which is the same size as CB. However, an 8x8 CB may be split into a single 8x8 PB or four 4x4 PBs.

Once intra prediction or inter prediction is used, the residual signal generated by the difference between the prediction block and the source video image block is converted to another domain for further discrete cosine conversion. (discrete cosine transform, DCT) or discrete sine transform (DST) encoding. In order to provide these conversions, each CU or individual CBs need to utilize one or more transform blocks (TBs).

Fig. 1G shows how the luminance CB 107-1 of the 1E or 1F is divided into different TBs 113-1, 113-2, 113-3, and 113-4. If the brightness CB 107-1 is 64x64 CB, TB 113-1 is 32x32 TB, TB 113-2 is 16x16 TB, TB 113-3 is 8x8 TB, and TB 113-4 is 4x4 TB. The luminance CB 107-1 can be divided into 4 TBs 113-1, 16 TBs 113-2, 64 TBs 113-3, and 256 TBs 113-4. One luminance CB 107-1 can be divided into TB 113 of the same size or TB 113 of different sizes.

The program for dividing CB into TB is based on quad-tree splitting. Therefore, one CB can be divided into one or more TBs, where each TB can be further divided into 4 TBs. Such a segmentation program can continue according to the size of the CB.

FIG. 1H is a diagram showing a quadtree division of luminance CB 107-1 of FIG. 1E or FIG. 1F, which is divided into TBs 113-1, 113-2, 113-3 or 113 of the 1G map by various division methods. 4. In the 1H picture, the size of the luminance CB 107-1 is 64x64. However, the size of the brightness CB 107-1 may also be 32x32 or 16x16.

In the 1Hth picture, the luminance CB 107-1 is divided into four 32x32 TBs 113-1. Each 32x32 TB can be further divided into four 16x16 TB 113-2. Each 16x16 TB can be further divided into four 8x8 TB 113-3s. Each 8x8 TB can be further divided into four 4x4 TBs 113-4.

TB 113 is then subjected to conversion by DCT or any HEVC standard. Transform units (TUs) summarize TB 113. One or more TBs are Adopted by each CB. The CB forms each CU. Therefore, the structure of the conversion unit (TU) is different for different CUs 108 and is determined by the CU 108.

FIG. 1I illustrates various differently divided TBs 113-1, 113-2, 113-3, and 113-4 of the TU 114. Each TU summarizes the TB of the 1G map or the 1H map. The 32x32 TU 114 can be a single 32x32 TB 113-1, or one or more 16x16 TB 113-2, 8x8 TB 113-3, or 4x4 TB 113-4. For a CU employing inter-prediction of HEVC, the TU may be larger than the PU such that the TU may contain PU boundaries. However, for a CU that employs intra prediction of HEVC, the TU may not cross the PU boundary.

FIG. 1J illustrates a quadtree partition of the TU 114 of FIG. 1I, which utilizes various TBs 113-1, 113-2, 113-3, or 113-4 of FIG. In Figure 1J, the size of the TU 114 is 32x32. However, the size of the TU can be 16x16, 8x8, or 4x4.

In Figure 1J, the TU 114 is split into a 32x32 TB 113-1 and four 16x16 TB 113-2. Each 16x16 TB can be further divided into four 8x8 TB 113-3s. Each 8x8 TB can be further divided into four 4x4 TB 113-4.

The CTU, CTB, CB, CU, PU, PB, TU or TB described in the disclosure may include any feature, size and property of the HEVC standard. The divisions described in Figures 1C, 1E, and 1F can also be applied to chroma CTB (Cb CTB 104), chroma CTB (Cr CTB 105), and chroma CB (Cb CB 109), and chroma CB (Cr CB 110). .

FIG. 2 illustrates a video encoder 200 that performs the encoding method of the present disclosure. Video encoder 200 may include one or more additional components that provide additional encoding functions for HEVC-SCC, such as palette mode, sample adaptive offset, and deblocking filtering. -blocking filtering). In addition, the present disclosure considers the intra prediction mode of ACT and other coding modes, such as the inter prediction mode of ACT.

Video encoder 200 receives one of the input source video frames. The input original video picture is first input to the Frame Dividing Module 202. The picture segmentation module 202 divides the original video picture into at least one original CTU (source CTU). The original CU (source CU) is then obtained by the original CTU. The size of the original CTU and the size of the original CU are determined by the picture segmentation module 202. Next, encoding is performed in a CU-by-CU manner. The original CU is outputted by the screen segmentation module 202, and then input to the Inter Prediction enabling adaptive color module 204, the Inter Prediction disabling ACT Module 206, and the intra prediction. The ACT module (Intra Prediction enabling ACT Module) 212 and the Intra Prediction disabling ACT Module 214 are enabled.

The original CU of the input picture is encoded by the inter prediction enable ACT module 204, which uses inter prediction techniques and enables adaptive color conversion (ACT) to determine a prediction of the original CU from the input picture. The original CU of the input picture is also encoded by the inter prediction disable ACT module 206, which utilizes inter prediction techniques and does not enable self-adaptability. Color Conversion (ACT) determines the prediction of an original CU from the input screen (ie, disables ACT).

A reference CU stored in a Frame Buffer 208 can be used for inter prediction. The original PU and PB are also obtained by the original CU, and are used in the inter prediction to enable the ACT module 204 and the inter prediction to disable the inter prediction program of the ACT module 206. Inter-frame prediction utilizes areas of video pictures at different times for motion detection. The interframe prediction enable ACT module 204 and the interframe prediction disable ACT module 206 have an encoded inter prediction CU that is predetermined to be the highest picture quality. The encoded inter prediction CU is then input to a Mode Decision Module 210.

The original CU of the input picture is also encoded by the intra prediction enable ACT module 212, which utilizes intra prediction techniques and enables adaptive color conversion (ACT) to determine a prediction of the original CU from the input picture.

The original CU of the input picture is also encoded by the intra prediction disable ACT module 214, which utilizes intra prediction techniques and does not enable adaptive color conversion (ACT) to determine a prediction of the original CU from the input picture (ie, disable ACT).

When the intra prediction enable ACT module 212 and the intra prediction disable ACT module 214 for intra prediction, the original CU stored in the same picture of the picture buffer 208 can be used. The original PU and PB are also obtained by the original CU, and are used for intra prediction to enable the ACT module 212 and the intra prediction to disable the intra prediction program of the ACT module 214. The encoded intra prediction CU is predetermined to be the highest picture quality. Enable ACT module 212 and intra prediction from intra prediction to disable ACT module 214 output The encoded intra prediction CU is input to the mode decision module 210.

In the mode decision module 210, the cost of the original CU is compared with the quality of the predicted CU by using the inter prediction enable ACT, the inter prediction disable ACT, the intra prediction enable ACT, and the intra prediction disable ACT. Based on the result of the comparison, the prediction CU of which coding mode is determined (for example, an inter prediction CU or an intra prediction CU). The selected predicted CUs are then passed to the Summing Modules 216, 218.

In the summation module 216, the original CU subtracts the selected predicted CU to provide a residual CU (residual CU). If the selected predicted CU is from one of the inter prediction enabled ACT module 204 and the intra prediction enabled ACT module 121, the switch 220 switches to position A. At position A, the remaining CU is input to the ACT Module 222 and then to the CCP, Transform, and Quantization Module 224. However, if the selected predicted CU is from one of the inter prediction disabled ACT module 206 and the intra prediction disabled ACT module 214, the switch 220 switches to position B. At location B, the ACT module 222 is skipped and is not executed during the encoding process. The remaining CUs are directly input from the summation module 216 to the CCP, conversion and quantization module 224.

In the ACT module 222, an adaptive color transform is performed on the remaining CUs. The output of the ACT module 222 is coupled to the CCP, conversion and quantization module 224.

CCP, conversion and quantization module 224 performs cross-component prediction (cross Component prediction, CCP), conversion (such as Discrete Cosine Transform (DCT) or Discrete Sine Transform (DST), and quantization of remaining CU. Output of CCP, conversion and quantization module 224 The Entropy Coding Module 226 and the Inverse CCP (Transform, and Quantization Module) 228.

Entropy encoding module 226 performs entropy encoding. For example, Context Adaptive Binary Arithmetic Coding (CABAC) can be executed to encode the remaining CUs. Any other entropy encoding procedure provided by HEVC can be performed in the entropy encoding module 226.

After performing entropy encoding, the encoded bit stream of the CU of the input video picture is output from video encoder 200. The output encoded bit stream can be stored in a memory, broadcast or networked through a transmission line, or provided to a display or the like.

In the inverse CCP, transform and quantization module 228, the inverse of the CCP, translation and quantization module 224 is determined by the remaining CUs to provide a reconstructed remaining CU.

If the selected predicted CU is from the inter prediction enabled ACT module 204 or the intra prediction enabled ACT module 212, the switch 230 switches to position C. At position C, the reconstructed remaining CU is input to the inverse ACT Module 232 and then to the summing module 218. However, if the selected predicted CU is from the inter prediction disable ACT module 206 or the intra prediction disable ACT module 214, the switch 230 switches to Position D. At position D, the inverse ACT module 232 is skipped and not executed, and the reconstructed remaining CUs are directly input to the summation module 218.

The inverse ACT module 232 performs an inverse of the adaptive color conversion of the ACT module 232 on the reconstructed remaining CUs. The output of the inverse ACT module 232 is input to the summation module 218.

In the summation module 218, the selected predicted CU from the mode decision module 210 is added to the reconstructed remaining CU to provide a reconstructed original CU (reconstructed source CU). The reconstructed original CU is then stored in picture buffer 208 for inter prediction and intra prediction by other CUs.

How the encoding methods 300, 400, and 500 described below are performed within the intra prediction enable ACT module 212. The encoding methods 300, 400, and 500 can improve encoding efficiency and encoding time.

The inter prediction enable ACT module 204, the inter prediction disable ACT module 206, the intra prediction enable ACT module 212, and the intra prediction disable ACT module 214 are not limited to being arranged in a parallel manner. In an embodiment, the inter prediction enable ACT module 204, the inter prediction disable ACT module 206, the intra prediction enable ACT module 212, and the intra prediction disable ACT module 214 may be sequentially arranged. The arrangement of the inter prediction enable ACT module 204, the inter prediction disable ACT module 206, the intra prediction enable ACT module 212, and the intra prediction disable ACT module 214 can be changed.

Figure 3 illustrates an encoding method 300 for determining whether a TU size evaluation needs to be performed for enabling, in accordance with an embodiment of the present disclosure. In the ACT enabled intra prediction encoding process. More specifically, encoding method 300 utilizes a threshold calculation for the CU size to determine whether an estimate of the TU size needs to be performed.

In step 304, component correlation analysis is performed on an original CU to determine if the coding mode of the ACT of the CU needs to be enabled. The correlation of the color components of the various pixels in the CU is analyzed. In each pixel, the correlation of color components is compared to a pixel correlation threshold to analyze whether the correlation is above, equal to, or below the pixel correlation threshold.

In a CU, the total number of pixels above the pixel correlation threshold is calculated, and the pixel equal to the pixel correlation threshold is also considered to be higher than the pixel correlation threshold. The total number of pixels is then compared to a CU correlation threshold.

If the total number of pixels is lower than the CU correlation threshold, it is determined that the color component of the CU has a low correlation. Therefore, the CU does not need ACT, so the flow proceeds to step 308, and the ACT is disabled in the encoding of the CU.

However, if the total number of pixels is higher than the CU correlation threshold, it is determined that the color component of the CU has a high correlation. In this case, ACT is the component correlation that needs to be used to remove the various pixels of the CU. When it is confirmed as high correlation, ACT is enabled and the flow proceeds to step 306. In step 306, under the intra prediction enable ACT, a summary mode decision is made.

The correlation analysis of step 304 can be performed further or selectively according to the color space of the CU. For example, in step 304, the color components of the pixels in the CU can be analyzed, and the color space of the CU can be determined. The color space can be determined as red, green, and blue (RGB) space or luminance and chrominance (YUV) space.

When it is determined that the color space is the RGB color space, the flow proceeds to step 306. In step 306, under the intra prediction enable ACT, a rough mode decision is performed. Since the RGB pixel components usually have high correlation, ACT is required to remove the correlation of the components of the respective pixels in the CU to isolate the pixel energy into a single component.

In contrast, when the color space is determined to be the YUV color space, the flow proceeds to step 308, and ACT is disabled. This is because the YUV pixel component usually has a low correlation, and most of the pixel energy is stored in a single pixel component. Since the further de-correlation of the CU pixel component does not create additional coding benefits, it is not necessary to enable ACT in the YUV pixel component.

In the intra prediction enable ACT module 212, when the encoding method 300 disables ACT, the intra prediction enable ACT encoding mode is disabled, and the intra prediction enable ACT module 212 does not output the prediction to mode decision module 210. .

The ACT module 204 is enabled for inter prediction. When the inter prediction encoding disable ACT, the inter prediction enable ACT encoding mode is disabled, and the inter prediction enabled ACT module 204 does not output the prediction to mode decision module 210.

In step 306, the intra prediction is enabled to perform a summary mode decision under ACT. The summary mode decision can be a cost-based mode decision. For example, in a summary mode decision, a selected coding mode that is low complexity cost can be determined to make a quick decision, which typically has the highest quality and lowest coding cost.

In step 310, a rate distortion optimization mode decision (RDO mode decision) is performed in the ACT-enabled encoding mode. Here, when ACT, CCP, conversion, quantization, and entropy coding are performed, the derivation of the original video and the bit cost of the coding mode are calculated. The variation can be obtained from an error calculation, such as a mean squared error (MSE). Next, the ROD analysis selects the coding mode with the lowest coding cost and the highest coding quality.

For example, in the intra prediction enable ACT module 212, 35 intra prediction modes (IPMs) are available for encoding. The intra prediction enable ACT module 212 uses the simple, low complexity coding cost decision method to select the lowest coding cost and the highest coding quality from the intra prediction modes in the summary mode decision of step 306. For example, the sum of absolute transform distortion (SATD) cost can be used to determine the low complexity coding cost of each IPM. For example, the lowest coding cost and the highest code quality can be selected by selecting 3 IPMs or selecting 8 IPMs. The intra prediction enable ACT module 212 performs an RDO mode decision for each selected IPM in the RDO mode decision of step 310. When ACT, CCP, conversion, quantization, and entropy coding are performed, Calculate the variance of the original video and the bit cost of the encoding for each selected IPM. The variation can be obtained from an error calculation, such as a mean squared error (MSE). Next, the IPM with the lowest coding cost and the highest coding quality is selected from the selected IPM by ROD analysis.

The above-described change process related to the intra prediction enable ACT module 212 can also be performed on the inter prediction enable ACT module 204. For example, when the inter prediction enable ACT module 204 performs the encoding method 300, in step 306, a summary mode decision of the optimal inter prediction of the temporally adjacent video frames is performed, which provides the lowest encoding cost and the highest encoding quality. At step 310, an RDO mode decision for inter prediction is performed. Here, when ACT, CCP, conversion, quantization, and entropy coding are performed, the original video's deviation and coding bit cost of the inter prediction are calculated. The variation can be obtained from an error calculation, such as a mean squared error (MSE). Next, the ROD analysis selects the inter prediction with the lowest coding cost and the highest coding quality.

At step 312, the CU size of the currently processed CU is calculated. The size of the CU may be NxN, where N may be 4, 8, 16, 32 or 64. The N value of the CU is compared to the threshold T1. The threshold T1 can be 4, 8, 16, 32 or 64. Based on the comparison result, it is determined whether the CU size is smaller than the threshold value T1, and thereby the size of the conversion unit to which the encoding mode is to be enabled is estimated. If the CU size is less than the threshold T1, the flow proceeds to step 314 for TU size ecision. However, if the CU size is equal to or greater than the threshold T1, the flow proceeds to step 316, and the TU size decision step of step 314 is skipped. At step 312, when the CU size is greater than The boundary value T1 determines the TU. If the CU size CU is equal to or greater than the threshold T1, the TU quadtree structure can be determined as the maximum possible TU size. For example, when the CU size is equal to or greater than the threshold T1, for a 64x64 PU, four 32x32 TUs can be determined. In another embodiment, when the CU size is equal to or greater than the threshold T1, the TU may be the same size as the PU for a 32x32, 16x16, 8x8 or 4x4 PU. For example, if the size of the PU is 32x32, the corresponding PU size may be 32x32.

Since the decision of the TU size is time consuming and increases the coding cost, step 312 can improve coding time and efficiency. Therefore, if the decision of the TU size can be omitted, the coding cost, that is, the time can be solved. Furthermore, the CU size is equal to or greater than the threshold T1 indicating that the content of the CU is not complicated. For example, a CU size greater than a threshold T1 may indicate that the video image has a wide range of areas without borders, dynamics, or complex images. Therefore, the decision of the TU size may not be required to efficiently perform encoding of the CU of high video quality.

In step 314, if the CU size is below the threshold T1, the decision of the TU size is performed. Here, the TU of the original CU is determined. With the RDO cost estimate of step 310, the TU size is analyzed, and the ACT conversion of the CU with the highest efficiency and high video quality has been obtained. For example, TU sizes of 4x4, 8x8, 16x16, and 32x32 can be analyzed. When the TU size of the ACT conversion that can achieve the highest efficiency is determined, this TU size is selected for the ACT conversion of the CU and proceeds to step 316. The selected TU size is used as the optimal TU quadtree structure size.

At step 316, a chroma mode decision is made (chroma mode) Decision). The determination of the chrominance mode is performed according to the determination of the prediction mode of step 310, and the determined prediction mode is used to cause chroma prediction to generate chrominance PU (chroma PU) and corresponding color. Degree TU (chroma TU). The TU determined from step 312 or step 314 can also be used to generate a chroma TU. The chroma TU is also subsampled according to the chroma format. Thus, in one embodiment, when the chroma format is 4:2:0 and the size of the luma TU is 32x32, the determined chroma TU is a 16x16 chroma TU.

At step 308, the intra prediction enable ACT module selects the optimal intra prediction mode and the procedure for selecting the optimal TU quadtree size is completed. The prediction and RDO costs have been generated and input to the mode decision module 210 for comparison with the RDO costs of the other prediction modules input to the mode decision module 210. For example, inter prediction enable ACT module 204 may generate prediction and RDO costs for ACT enabled CUs and input predicted CU and RDO costs to mode decision module 210. The inter prediction disable ACT module 206 and the intra prediction disable ACT module 214 also generate predicted CU and RDO costs and enter their respective predicted CU and RDO costs to the mode decision module 210. The mode determining module 210 compares the predicted CU and RDO costs input by the inter prediction enable ACT module 204, the inter predictive disable ACT module 206, the intra prediction enable ACT module 212, and the intra prediction disable ACT module 214. And the predicted CU to be input to the summation modules 216, 218 is determined.

FIG. 4 illustrates an encoding method 400 in accordance with another embodiment of the present disclosure that determines whether ACT needs to be enabled in accordance with another embodiment of the present disclosure. More specifically, The encoding method 400 utilizes a determination of the correlation between the threshold calculation of the CU size and the color component of the CU pixel. Depending on the threshold calculation, ACT can be enabled or disabled. For the same reference numerals, reference may be made to the aforementioned related description.

At step 304, component correlation analysis is performed on the original CU to determine if ACT needs to be enabled or disabled. Step 304 is as described for encoding method 300. If the correlation of the color components of the CU is high, ACT is enabled and the flow proceeds to steps 306, 310, 314, 316, and 308 (same as encoding step 300 above). However, if the correlation is low, the flow proceeds to step 402.

At step 402, the size of the currently processed CU is determined. As previously mentioned, the CU size is NxN, where N can be 4, 8, 16, 32 or 64. The N value of the CU is compared to a threshold T2 to compare whether the CU size is less than the threshold T2. The threshold T2 can be 4, 8, 16, 32 or 64. If the CU size is less than the threshold T2, ACT is enabled and the flow proceeds to step 310 as determined by the RDO mode of step 310 of the encoding method 300. However, if the CU size is equal to or greater than the threshold T2, the flow proceeds to step 308, and ACT is disabled.

The ACT module 204 is enabled for inter prediction. When ACT is disabled in the encoding method 400, the output of the inter prediction enable ACT module 204 is an inter prediction CU to which ACT is not applied. Therefore, in this case, the CU outputted by the inter prediction enable ACT module 204 is the same as the output of the inter prediction disable ACT module 206. Similarly, the ACT module 212 is enabled in the intra prediction. When the ACT is disabled in the encoding method 400, the output of the intra prediction enable ACT module 212 is within the frame in which ACT is not applied. Predict CU. Therefore, in this case, the output prediction CU of the intra prediction enable ACT module 212 is the same as the output of the intra prediction disable ACT module 214.

Since the CU size is the same or larger than the threshold T2 indicating that the content of the CU is not complicated, step 402 can improve the encoding time and the encoding efficiency. A CU size greater than the threshold T2 may indicate that the video image has a wide range of areas without borders, dynamic or complex images. In order to efficiently encode a CU under the color component that has been sufficiently de-correlated, ACT may not be needed.

FIG. 5 illustrates an encoding method 500 according to another embodiment of the present disclosure, which determines whether ACT needs to be enabled and whether TU size estimation needs to be performed through two threshold calculations according to another embodiment of the present disclosure. More specifically, encoding method 500 uses a first threshold calculation for the CU size and a correlation decision to determine whether to enable the CU pixel color component of ACT. The encoding method 500 also uses a second threshold calculation for the CU size to determine if an estimate of the TU size needs to be performed. For the same reference numerals, reference may be made to the aforementioned related description.

At step 304, component correlation analysis is performed on the original CU to determine if ACT needs to be enabled or disabled. Step 304 is as described for encoding method 300. If the correlation of the color components of the CU is high, ACT is enabled and the flow proceeds to step 306 to make a summary mode decision and the RDO mode decision of step 310. Steps 306 and 310 are as described in the aforementioned encoding method 300. However, if the correlation is low, the flow proceeds to step 402.

At step 402, the size of the currently processed CU is determined (as described above) The encoding method 400 of Figure 4). If the CU size is less than the threshold T2, ACT is enabled and proceeds to step 310 for RDO mode decision. However, if the CU size is equal to or greater than the threshold T2, the flow proceeds to step 308, and ACT is disabled.

The ACT module 204 is enabled for inter prediction. When ACT is disabled in the encoding method 500, the output of the inter prediction enable ACT module 204 is an inter prediction CU to which ACT is not applied. Therefore, in this case, the CU outputted by the inter prediction enable ACT module 204 is the same as the output of the inter prediction disable ACT module 206.

Similarly, the ACT module 212 is enabled for intra prediction. When ACT is disabled in the encoding method 500, the output of the intra prediction enabled ACT module 212 is an intra prediction CU that does not apply ACT. Therefore, in this case, the output prediction CU of the intra prediction enable ACT module 212 is the same as the output of the intra prediction disable ACT module 214.

At step 310, the RDO mode determines the content as described in the aforementioned encoding method 300.

At step 312, the current processed CU size is calculated as described in the foregoing encoding method 300 to determine if the CU size is less than the threshold T1. If the CU size is less than the threshold T1, the flow proceeds to step 314 to make a TU size decision. However, if the CU size is equal to or greater than the threshold T1, the flow proceeds to step 316, and the TU size decision of step 314 is skipped. The decision process of steps 314, 316 is as in the encoding method 300 described above.

The thresholds T1 and T2 can be set to the same or different values.

The encoding method 500 of Figure 5 combines threshold calculation to improve encoding Efficiency and time. As described above, the CU size equal to or greater than the threshold T2 indicates that the content of the CU is not complicated, and a borderless, dynamic or complex pattern of a wide range of areas can be expected. In order to efficiently encode a CU under the color component that has been sufficiently de-correlated, ACT may not be needed. Furthermore, after the TU size decision of step 314 is omitted, the coding cost can be saved.

FIG. 6 illustrates an encoding method 600 (similar to encoding method 300) in accordance with another embodiment of the present disclosure that determines whether TU size estimation needs to be performed in an intra-prediction program that enables ACT in accordance with another embodiment of the present disclosure. More specifically, the scribing method 600 uses a threshold calculation for the CU size and determines whether a TU size estimation needs to be performed based on the threshold calculation.

At step 304, component correlation analysis is performed on the original CU to determine if ACT needs to be enabled or disabled. Step 304 is as described for encoding method 300. If the correlation of the color components of the CU is high, ACT is enabled and the flow proceeds to step 306 to make a summary mode decision and the RDO mode decision of step 310. Steps 306 and 310 are as described in the aforementioned encoding method 300. However, if the correlation at step 304 is low, or the color space is determined to be a YUV color space, the ACT encoding mode is enabled and proceeds directly to step 310, but the summary mode decision of step 306 is not performed. Here, for low correlation pixel components or YUV color spaces, ACT is still enabled to confirm that the de-correlation of pixel components may result in additional coding benefits.

At step 310, the RDO mode determines the calculation as in the aforementioned encoding side. Method 300.

At step 312, the current processed CU size is calculated as described in the foregoing encoding method 300 to determine if the CU size is less than the threshold T1. If the CU size is less than the threshold T1, the flow proceeds to step 314 to make a TU size decision. However, if the CU size is equal to or greater than the threshold T1, the flow proceeds to step 316, and the TU size decision of step 314 is skipped. The decision process of steps 314, 316 is as in the encoding method 300 described above.

The thresholds T1 and T2 can be set to the same or different values.

The decoding method that performs the reverse steps of the encoding methods 300, 400, 500, 600 can efficiently decode the video encoded by the encoding methods 300, 400, 500, 600. Accordingly, the above disclosure of the present disclosure is sufficient to understand the decoding method of performing the reverse steps of the encoding methods 300, 400, 500, 600. The foregoing disclosure is also sufficient to understand other decoding procedures required to decode the video encoded by the encoding methods 300, 400, 500, 600.

If the large CU uses 1PM as the screen visual content, it may indicate that the content of the area is not complicated and does not need to estimate the size of the TU. Therefore, the IPM of the non-444 chroma format is prohibited from splitting the TU of some large CUs. Figure 7 illustrates the flow of the IPM in a non-444 chroma format. Steps 306 and 310 are as described in the aforementioned encoding method 300. At step 310, the RDO mode decision is calculated as the aforementioned encoding method 300.

At step 311, it is determined whether the chroma format is non-444. If the chroma format is non-444, then step 312 is entered. If the chroma is not 444, go to the step 314, determined by the size of the near-row TU.

At step 312, the current processed CU size is calculated as described in the foregoing encoding method 300 to determine if the CU size is less than the threshold T1. If the CU size is less than the threshold T1, the flow proceeds to step 314 to make a TU size decision. However, if the CU size is equal to or greater than the threshold T1, the flow proceeds to step 316, and the TU size decision of step 314 is skipped. The decision process of steps 314, 316 is as in the encoding method 300 described above.

The thresholds T1 and T2 can be set to the same or different values.

FIG. 8 illustrates a system 700 for performing the encoding and decoding methods of the present disclosure. System 700 includes a non-transitory computer-readable medium 702, which can be a memory that stores array instructions. Such instructions may be executed by processor 704. It is noted that one or more non-transitory computer readable media 702 and/or one or more processors 704 can be selectively employed to perform the encoding and decoding methods of the present disclosure.

The non-transitory computer readable storage medium 702 can be any type of non-transitory computer-readable storage medium (non-transitory CRM). The non-transitory computer readable recording medium may include a floppy disk, a flexible disk, a hard disk, a hard drive, and a solid state disk. Drive), magnetic tape, any magnetic data storage medium, CD-ROM, any optical data storage medium, any physical medium with a hole pattern, Dynamic Random Access Memory (RAM), Programmable Read Only Memory (PROM), Erasable Programmable Read Only Memory (EPROM), Flash Erasable Programmable Read Only Memory (FLASH-EPROM) ), any flash memory, non-volatile memory (NVRAM), cache, register, memory chip, cartridge, and network. The computer readable recording medium can store array instructions executed by at least one processor. Such instructions include steps or stages that cause the processor to perform the encoding and decoding methods of the present disclosure. Furthermore, one or more computer readable recording media can be used to implement the encoding and decoding methods of the present disclosure. "Computer-readable recording media" contains tangible objects but does not contain carrier carrier signals and transient signals.

The processor 704 can be any type of digital signal processor (DSP), an application specific integrated circuit (ASIC), a digital signal processing device (DSPD), and can be programmed. Logic device (PLD), field programmable gate arrays (FPGA), controller, micro-controller, micro-processor, computer or any Other electronic components capable of performing the encoding and decoding methods of the present disclosure.

Experimental result

The experimental results of the encoding method of the present disclosure are described below.

The laboratory here uses the HEVC SCC reference model, SCM 4.0 under common test conditions (CTC). The coding performance of the coding method of the present disclosure is compared with the reference model of HEVC. HEVC reference The model takes the encoding time A for encoding. The test coding method of the present disclosure takes the coding time B to perform coding. The coding time percentage is the coding time B divided by the coding time A. The experiment can use the HEVC general test procedure. Video can mix text, images, motion pictures, mixed content, animations, and camera captures. The video can be an RGB color space with a picture quality of 720p, 1080p, or 1440p and a YUV color space. The experiment uses full intra prediction, random access, and low-B prediction under lossy conditions. Full intra prediction uses the information in the picture being compressed to compress the video picture, while random access and low B prediction use the previously encoded picture and the information of the picture currently being compressed to compress the video picture. In the following description, the low B prediction may also refer to a low delay B prediction. In each experiment, the encoding time and decoding time are recorded as a percentage, which represents the ratio of the encoding method to the decoding method relative to the reference model. Relative to the original video source, a positive percentage for each G/Y, B/U, and R/V component indicates a bit rate coding loss, and a negative percentage indicates a bit rate coding gain (bit rate coding). Gain). For example, a 0.1% value for the G/Y component indicates that the G/Y component of the encoded video has a coding loss of 0.1% relative to the G/Y component of the original video. In another example, a value of -0.1% of the G/Y component indicates that the coded gain of the G/Y component of the encoded video relative to the G/Y component of the original video is 0.1%.

Please refer to the coding method 500 of Figure 5 and Table 1 below. In the encoding method 500, the laboratory is executed under the following three settings. In the first setting, the threshold T2 and the threshold T1 are both set to 64. In setting 2, the threshold T2 is set to 64, Pro The threshold T1 is set to 32. In setting three, the threshold T2 is set to 64, and the threshold T1 is set to 16. The intra prediction is a predetermined coding mode.

For setting one, when the pixel component has low correlation, a CU whose size is greater than or equal to 64x64 is encoded in a manner that does not enable ACT. CUs smaller than 64x64 are encoded in an ACT-enabled manner. Furthermore, in the case where the CU size is greater than 64x64, step 314 of TU size determination is omitted. In the case where the CU size is less than 64x64, step 314 of the TU size decision is performed.

In the second setting, when the pixel component has low correlation, the CU whose size is greater than or equal to 64x64 is encoded in a manner that does not enable ACT. CUs smaller than 64x64 are encoded in an ACT-enabled manner. Furthermore, in the case where the CU size is larger than 32x32, step 314 of TU size determination is omitted. In the case where the CU size is less than 32x32, step 314 of the TU size decision is performed.

In setting three, when the pixel component has low correlation, a CU whose size is greater than or equal to 64x64 is encoded in a manner that does not enable ACT. CUs smaller than 64x64 are encoded in an ACT-enabled manner. Furthermore, in the case where the CU size is larger than 16x16, step 314 of TU size determination is omitted. In the case where the CU size is less than 16x16, step 314 of the TU size decision is performed.

As shown in Table 1, the coding performance of setting 1, setting 2 and setting 3 is improved. Setting one reduced the coding complexity by 3%, and setting two reduced the coding complexity by 6%. Setting three reduces the encoding complexity by 9% (set three to reduce the most). Therefore, all settings can improve coding efficiency. Each setting has an improvement in coding time and efficiency at a minimum loss of bit rate.

Please refer to coding method 500 and Tables 2 and 3 below. Here, the experiment is performed under full frame, random access, and low delay B. In the first experiment, the critical value T2 and the critical value T1 are both set to 32. In the second experiment, the critical value T2 and the critical value T1 are both set to 16. As with encoding method 500, in experiment one, size A CU greater than or equal to 32x32 disables TU evaluation, and a size greater than or equal to 32x32 is encoded in a manner that does not enable ACT. In Experiment 2, a CU with a size greater than or equal to 16x16 disables TU estimation, and a size greater than or equal to 16x16 is encoded in a manner that does not enable ACT. CUs smaller than 16x16 are coded in an ACT-enabled mode. The experiment was performed under lossy conditions and full frame intra block copy.

As shown in Table 2, in Experiment 1, the all intra mode reduced the coding complexity by 5%. Random access and low latency B each reduce the coding complexity by 1%. Each setting shows a very low bit rate loss, with almost no bit rate changes in full intraframe and random access.

In Experiment 2, the full intra mode reduced the coding complexity by 8%. Random access reduces the coding complexity by 1%. Low latency B does not change the coding complexity. Compared to Experiment 1, each mode has more bit rate loss, but the bit rate loss is still kept to a minimum (only in the fractional range of percentages). Compared to the original video, the encoded video only slightly reduces the bit rate, so only a small portion of the video quality is lost. Since the encoding method 500 improves the encoding time, such video quality is acceptable for most applications.

As shown in Table 3, in Experiments 1 and 2, the mode did not change in all or on average. The coding complexity of the most ratio was reduced in the full frame (1% reduction for each experiment).

Please refer to coding method 500 and Figure 4 below in Figure 5. Here, the experiment was performed in a lossy condition, a 4-CTU intra block copy technique, and a 4:4:4 chroma mode. The intra block copy technique utilizes motion vectors to copy a block from a previously encoded CU to the current encoded video picture. 4-CTU indicates the range in which the motion vector can be searched.

In Experiment 1, the critical value T2 and the critical value T1 were both set to 32. In Experiment 2, the critical value T2 and the critical value T1 are both set to 16. As with encoding method 500, in experiment one, a CU with a size greater than or equal to 32x32 disables the TU estimate. In Experiment 2, a CU with a size greater than or equal to 16x16 disables the TU estimate. In Experiment 1, CUs with sizes larger than 32x32 enable ACT, and CUs with sizes greater than or equal to 32x32 disable ACT. In Experiment 2, CUs with sizes smaller than 16x16 enable ACT, and CUs with sizes greater than or equal to 16x16 disable ACT.

As shown in Table 4, in Experiment 1 and Experiment 2, the full intraframe, random access or low latency B mode is the minimum bit rate change. The maximum coding complexity was reduced in the full frame, which was reduced by 5% in Experiment 1 and by 8% in Experiment 2.

Please refer to coding method 400 in Figure 4 and Tables 5.1 and 5.2 below. Here, the threshold T2 is set to 64. Therefore, when the component correlation analysis of step 304 analyzes that the color component of the CU has a low correlation, step 402 is performed to determine whether the CU size is less than 64x64. If the CU size is less than 64x64, ACT is enabled and the RDO mode decision of step 310 is performed. If the CU size is greater than or equal to 64x64, ACT is disabled and proceeds to step 308. Experiment 1 uses lossy all intra encoding mode of full frame intra block copy, and experiment 2 uses lossy full intra coding mode of 4 CTU IBC technique. . The chroma mode was chosen to be 4:4:4 for each experiment.

As shown in Table 5.1, under the YUV color space and full-frame, lossy, full-picture intra-frame copying technique, the encoding method 400 reduces the encoding time by 1% to 3% with minimal bit rate loss. As shown in Table 5.2, under the full-frame, lossy, 4 CTU intra-frame copy technique, the coding method 400 reduces the coding time at a minimum bit loss ratio similar to Experiment 1 of Table 5.1.

Please refer to encoding method 400 and Table 6 below. Here, the threshold T2 is set to 64. Lossless intra encoding is performed in the 4:4:4 chroma mode.

In the YUV color space, the encoding method saves 0% to 2% of the encoding time.

Please refer to the coding method 300 of Figure 3 and Table 7 below. Here, the critical value T1 is set to 32 in Experiment 1, and set to 16 in Experiment 2. As in the encoding method 300, in Experiment 1, when the CU size is greater than or equal to 32x32, the TU size decision of step 314 will be omitted; when the CU size is less than 32x32, the TU size decision of step 314 is performed. In experiment 2, when the CU size is greater than or equal to 16x16, the TU size decision of step 314 will be omitted; when the CU size is less than 16x16, the TU size decision of step 314 is performed. The experiment performs a lossy full intraframe encoding that enables ACT.

The coding time of Experiment 1 was saved by 3% to 6%. The coding time of Experiment 2 was saved by 6% to 10%. Therefore, only in CU sizes below 32x32 or 16x16 The TU size decision is allowed below to help with coding efficiency.

The above description is used to illustrate the technology of the present disclosure, but it is not intended to limit the content of the present invention. Modifications and adjustments of the embodiments are within the scope of the disclosure. For example, the disclosed embodiments include both software and hardware, but the systems and methods of the present disclosure can be implemented only in hardware.

The software developer can develop a computer program based on the method of the present disclosure, which can be developed using various computer program technologies. For example, a program fragment or a program module can be developed by Java, C, C++, a combination language, or any other programming language. One or more software segments and modules can be installed in a computer system, non-transitory computer readable media, or existing communication software.

Furthermore, the scope of the disclosure is to be construed as being limited, modified, omitted, and combinations (e.g., combinations of different embodiments), applications, or alternatives. The components of the patent application are to be interpreted in the broadest scope and not limited to the scope of the embodiments. In addition, the steps of the method can be modified (including the order of adjustment, insertion or deletion steps). Although the disclosure has been disclosed above in the preferred embodiments, it is not intended to limit the disclosure. The scope of protection of this disclosure is subject to the definition of the scope of the patent application.

Other embodiments of the invention will be apparent to those skilled in the art of the invention. The scope of the disclosure encompasses various variations, implementations, and applications in conjunction with the general knowledge. The specification and the examples are intended to be illustrative only, and the scope of the disclosure is defined by the scope of the appended claims.

300‧‧‧ coding method

304‧‧‧ Component correlation analysis

306‧‧‧Summary mode decision

End of 308‧‧

310‧‧‧RDO mode decision

312‧‧‧Determination of whether the CU size is greater than the critical value T1

314‧‧‧ TU size decision

316‧‧‧Chroma mode decision

Claims (17)

A video encoding method includes: receiving an original video frame; dividing the original video frame into a coding tree unit; determining a coding unit from the coding tree unit; enabling or Disabling a coding mode of the coding unit; if the coding mode is enabled, determining whether to estimate a size of a transform unit in the coding mode enabled; and determining the coding unit when the coding mode is enabled The conversion unit; wherein the coding unit has a size of NxN. The method of claim 1, further comprising: determining a color space of the coding unit; wherein determining the color space of the coding unit comprises determining whether the color space is a red, green, and blue (RGB) Color space or a luminance and chrominance (YUV) color space. The method of claim 2, further comprising: if the encoding mode is enabled to enable an intra prediction mode of an adaptive color transform (ACT), when When the color space is judged as the RGB color space, a cost-based mode decision is performed. The method of claim 2, further comprising: if the encoding mode is enabled to enable an intra prediction mode of an adaptive color transform (ACT), when When the color space is judged as a luminance and chrominance (YUV) color space, execution A cost-based mode decision. The method of claim 2, further comprising: disabling the coding mode of the coding unit when the color space is determined to be the YUV color space and N is greater than or equal to a threshold. The method of claim 2, further comprising: determining whether N is less than a threshold; and when the color space is determined to be the YUV color space and N is less than the threshold, enabling the encoding mode, the encoding mode Enable an adaptive color transform (ACT). The method of claim 2, further comprising: determining whether N is less than a first threshold; determining whether N is less than a second threshold; when the color space is determined to be the YUV color space and N is less than the first a threshold value, the encoding mode is enabled, the encoding mode enabling an adaptive color transform (ACT); and when N is less than the second threshold, estimating a size of the converting unit in the encoding mode, the encoding mode Enable this adaptive color conversion. The method of claim 2, further comprising: determining whether N is less than a first threshold; determining whether N is greater than or equal to a second threshold; when the color space is determined to be the YUV color space and N Less than the first threshold, the encoding mode is enabled, the encoding mode enables an adaptive color transform (ACT); and when N is greater than or equal to the second threshold, the conversion is not estimated in the encoding mode. The size of the unit that enables this adaptive color conversion. The method of claim 1, further comprising: determining whether N is greater than or equal to a threshold; and when the N is greater than or equal to the threshold and enabling the encoding mode to enable an adaptive color transform (adaptive color transform) , ACT), the size of the conversion unit is not evaluated. The method of claim 1, further comprising: determining whether N is less than a threshold; and when N is less than the threshold and enabling the encoding mode to enable adaptive color transform (ACT), evaluating the The size of the conversion unit; and the size of the conversion unit. The method of claim 1, further comprising: if the original video picture is non-444 (non-444) and the size of the coding unit is smaller than NxN, the size of the conversion unit is evaluated. A video encoding system includes: a memory for storing a set of instructions; and a processor for executing the set of instructions, the set of instructions comprising: receiving an original video frame; dividing the original video The picture is a coding tree unit; a coding unit is determined from the coding tree unit; one of the coding units is enabled or disabled; if the coding mode is enabled, the picture is enabled The encoding mode determines whether to estimate the size of a transform unit; The coding mode enabled to determine the conversion unit of the coding unit; wherein the coding unit has a size of NxN. The system of claim 12, wherein the processor is configured to execute the set of instructions further comprising: determining a color space of the coding unit; wherein the color space is determined to be a red, green, and blue (RGB) color space or a luminance and chrominance (YUV) color space. The system of claim 13, wherein the processor is configured to: determine whether N is less than a first threshold; determine whether N is less than a second threshold; when the color space is determined For the YUV color space and N is less than the first threshold, the encoding mode is enabled, the encoding mode enabling an adaptive color transform (ACT); and when N is less than the second threshold, in the encoding mode The size of the conversion unit is estimated, which enables the adaptive color conversion. The system of claim 13, wherein the processor for processing the set of instructions further comprises: determining whether N is less than a first threshold; determining whether N is greater than or equal to a second threshold; The space is determined to be the YUV color space and N is less than the first threshold, the encoding mode is enabled, the encoding mode enables an adaptive color transform (ACT); and when N is greater than or equal to the second threshold , the conversion is not estimated in the encoding mode The size of the unit that enables this adaptive color conversion. The system of claim 12, wherein the processor is configured to process the set of instructions further comprising: if the original video frame is non-444 (non-444) and the size of the coding unit is less than NxN, The size of the conversion unit. A non-transitory computer readable recording medium for storing a set of instructions executed by one or more processors to perform a video encoding method, wherein the video encoding method comprises: receiving an original video frame ( Source video frame); dividing the original video picture into a coding tree unit; determining a coding unit from the coding tree unit; enabling or disabling a coding mode of the coding unit; If the encoding mode is enabled, determining whether to optimize a size of a transform unit in the encoding mode enabled; and determining the converting unit of the encoding unit when the encoding mode is enabled; wherein the size of the encoding unit is NxN.