Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
12th February 2014, 06:57 | #61 | Link | |
Registered User
Join Date: Feb 2014
Posts: 4
|
Quote:
This paper uses the collocated texture luma block to try to simplify one mode of wedgelet predictions. From the two lines of code I pasted before, (I think) I am finding this collocated texture luma block. Once this block is found, the paper applies a 1-d filter on each of its side. Now to this this, I am assuming that he must extract the pixels of this block in order to do so. That is where I am having difficulties. What I mainly want to do is extract the pixels of this block (and possible save them in this temp new block), apply the 1-D filter to each of its sides, and continue from there. |
|
1st March 2014, 00:25 | #66 | Link | |
ангел смерти
Join Date: Nov 2004
Location: Lost
Posts: 9,558
|
Quote:
|
|
7th March 2014, 00:38 | #68 | Link |
ангел смерти
Join Date: Nov 2004
Location: Lost
Posts: 9,558
|
Do you mean that you changed g_quantTSDefault4x4? Did you set ScalingList to 1? Because unless you specify using a custom scaling list, it always scales by a scalar (flat "matrix") no matter what you change to g_quantTSDefault4x4 and g_quantIntraDefault8x8 to. Those lists are built-in custom quant matrices (even if they are flat), not the standard scalar. In rExt, it's a separate value, g_quantScales; in HM, it was a bit-shift, not sure if it uses g_quantscales now too.
|
9th March 2014, 03:31 | #69 | Link |
Registered User
Join Date: Feb 2014
Posts: 3
|
Yes Thanks, i have set ScalingList as 1 and now i got different values. Basically i need some already done Research papers on usage of user defined Scale Matrices for Good Compression Compared to Default Matrices. I do not have any idea of how to Manipulate the values to get better Results. Also they are using Same matrices for Chroma and Luma. One more Query is g_quantTSDefault4x4 and g_quantIntraDefault8x8 are Default matrices. But g_QuantScales is an array with 6 values, can you tell what for this array is used.
|
9th March 2014, 23:29 | #71 | Link | |
Guest
Posts: n/a
|
Quote:
Code:
#=========== Quantization Matrix ================= ScalingList : 0 # ScalingList 0 : off, 1 : default, 2 : file read ScalingListFile : scaling_list.txt # Scaling List file name. If file is not exist, use Default Matrix. |
|
8th April 2014, 19:31 | #72 | Link |
Registered User
Join Date: Feb 2014
Posts: 4
|
GoP Structure
Hi, could someone confirm if the Group of Pictures Structure for the Random Access Configuration in HM is Hierarchical B Prediction (like the one displayed in: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.84.932&rep=rep1&type=pdf)
The GoP is as follows: # Type POC QPoffset QPfactor tcOffsetDiv2 betaOffsetDiv2 temporal_id #ref_pics_active #ref_pics reference pictures predict deltaRPS #ref_idcs reference idcs Frame1: B 8 1 0.442 0 0 0 4 4 -8 -10 -12 -16 0 Frame2: B 4 2 0.3536 0 0 0 2 3 -4 -6 4 1 4 5 1 1 0 0 1 Frame3: B 2 3 0.3536 0 0 0 2 4 -2 -4 2 6 1 2 4 1 1 1 1 Frame4: B 1 4 0.68 0 0 0 2 4 -1 1 3 7 1 1 5 1 0 1 1 1 Frame5: B 3 4 0.68 0 0 0 2 4 -1 -3 1 5 1 -2 5 1 1 1 1 0 Frame6: B 6 3 0.3536 0 0 0 2 4 -2 -4 -6 2 1 -3 5 1 1 1 1 0 Frame7: B 5 4 0.68 0 0 0 2 4 -1 -5 1 3 1 1 5 1 0 1 1 1 Frame8: B 7 4 0.68 0 0 0 2 4 -1 -3 -7 1 1 -2 5 1 1 1 1 0 Also, If it is indeed Hierarchical B, does it make a difference that all frames are as Type B, whilst the POC 8 from the link is a I/P frame? Thanks. |
20th April 2014, 07:34 | #75 | Link | |
Registered User
Join Date: Nov 2012
Posts: 41
|
Quote:
__________________
John @ Parabola Research Limited - HEVC conformance and technology http://www.parabolaresearch.com/ |
|
8th May 2014, 01:21 | #76 | Link |
Registered User
Join Date: Oct 2009
Posts: 2
|
Why long-term reference pictures are identified by slice_pic_order_cnt_lsb?
I'm trying to understand how DPB management and reference list construction work in H.265. The logic of the recommendation is hard to grasp.
Why short-term reference pictures for the purpose of RPS can only be identified in DPB by PicOrderCntVal, but long-term either by PicOrderCntVal or slice_pic_order_cnt_lsb? slice_pic_order_cnt_lsb is not unique within a GOP. So there can be a situation that there are two pictures in DPB with the same slice_pic_order_cnt_lsb. How identify a picture for a purpose of a long-term reference then? What is the reason at all of this complication for long-term reference pictures? Wouldn't it be easier just to use PicOrderCntVal always? |
22nd May 2014, 13:37 | #77 | Link |
Registered User
Join Date: Apr 2014
Posts: 2
|
intra-prediction implementation by MATLAB
Hi,
I am working on my thesis as implementation of intra-prediction by MATLAB for an image. I am almost stuck in this thesis. First of all I need a clear process of how to traverse the image in z-order scan. (how z-scan order really works) Second I couldn't find so far a very clear description of intra-prediction algorithm. May someone help me in this regard? |
26th May 2014, 22:46 | #79 | Link | |
Moderator
Join Date: Jan 2006
Location: Portland, OR
Posts: 4,750
|
Quote:
The first post of this thread is a good place to start. |
|
31st May 2014, 03:40 | #80 | Link | |
Registered User
Join Date: Apr 2014
Posts: 2
|
intra-prediction implementation by MATLAB
Quote:
1- If I am right for detecting which mode should be used for predicting a PU is using the mode with least RD cost with the function: C = DHad + λ ·Rmode How should I calculate the RD cost? no specific declaration about what is λ and how should I obtain or calculate it, what is Dhad which has been just translated in "absolute sum of Hadamard transformed residual signal for a PU" and I cannot understand what it exactly is and how should I obtain it? what is Rmode and how should I calculate or obtain it? Is it possible to use SAE which was used in h.264 instead of RD cost or something more simpler than RD cost? 2- According to Fig.1 of this pdf: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.352.3008&rep=rep1&type=pdf in HEVC there are one row and one buffer columns of samples which is used for prediction of a PU. Do I always have to have the extension for above reference row from (RN+1,0.. R2N,0) and the extension for left reference column from (R0,N+1.. R0,2N) at the same time or with respect to the selected angle for the block prediction I should have one of these extension at a time for each block? 3- For some angles I should do linear interpolation and for some extrapolation. I couldn't find any method or function to implement these sample generation for reference samples. 4- How should I implement the prediction for angular modes except DC,vertical and Horizontal. in this patent document: http://www.google.com/patents/US20130016777 in the paragraph which contains this line:"FIG. 4 shows an embodiment of an intra prediction scheme in a vertical mode" (Please Find this line in this document) and the next paragraph there is a clear implementation of vertical and 45 degree modes. However, no clear description on how other angular modes should be implemented could be found neither in this document nor in the previous mentioned PDF in this post. Moreover, the description for the vertical and 45 degree in this patent document is somehow different from interpolation or extrapolation, isn't it? Thank you in advance for all further helps... Last edited by mas_np; 31st May 2014 at 03:56. Reason: Adding something more to the post |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|