Questions tagged [hevc]

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hevc number of coding tree blocks per slice

I trying to determine the number of coding tree blocks contained in each slice of a hevc picture without actually doing any decoding - aside from sps pps and slice header parsing. Can the end slice address be calculated from the slice header?
AFX
1

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1

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216

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How to find the first NALunit of one complete video frame in raw HEVC/H.265 stream?

In a raw HEVC/H265 elementary stream, how to find the first NALunit of one video frame? Access unit delimiter/access_unit_delimiter_rbsp() seems to be a good choice, but it is optional in the video stream.
ravin.wang
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0

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iOS VTDecompressionSessionDecodeFrame error -12909 when decoding HEVC

I have some trouble with streaming raw H.265 over rtsp when using VTDecompressionSessionDecodeFrame. The 3 main steps I do are the following ones: OSStatus status = CMVideoFormatDescriptionCreateFromHEVCParameterSets(kCFAllocatorDefault, 3, parameterSetPointers, parameterSetSizes, (int)kNALUHeaderSi...
Mench
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How to get information and output Sum of Absolute Difference in HM Test Model?

I am using software reference HM Test Model 16.9, How to get information and output of Sum of Absolute Difference in HM Test Model? Is it possible to configure it via config file and save it into text file? I already read the software manual but can't find any. Thanks in advance
kaito87
1

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1

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288

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ffmpeg command x265 param option for android device

I wanto encode HEVC video to be played on my android phone. in this page from anroid says that only Lollipop+ will supported HEVC. and the Profile : main, Level 3. But ffmpeg encoding x265 not supproted profiling. I know some answer of this question, But thats is for Profile main10. I need -x265-par...
sonya
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2

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92

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HEVC reference software : Modification to encode CTUs line by line instead of slice segments

Looking inside the Void TEncSlice::encodeSlice of the official HM Test software, I found that in a loop the encoder is trying to encode every CTU inside a slice segment ie 512 CTUs in a unique slice in my script example. for( UInt ctuTsAddr = startCtuTsAddr; ctuTsAddr < boundingCtuTsAddr; ++ctuTsAd...
Maverick
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175

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How to decode a video at a certain fps using ffmpeg

I am working on video decoding using FFmpeg. When I try to decode a video which is encoded with h265 at a certain fps (ex: fps=25), the result is a decoded video but at a different fps. How can I decode a video at exactly fps=25, even if I have a high miss rate or dropped frames? I use this command...
Mohammed_BEY
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2

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changing HM reference software to display some information about the bitstream

I am very new to the HM HEVC (and the JEM) reference software, and I am currently trying to understand the source code. I want to add some lines to display for each component: name of Algo (i.e. inter/intra Algos) + length of the bitstream+ position in output bin file. To know which component cost...
Mourad
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711

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Set GOP length for HEVC-Encoding in ffmpeg

I want to encode an xxx.y4m file to hevc and set the GOP-length to a particular value, open and closed gop. To encode I'm using : ...>ffmpeg -i xxx.y4m -c copy xxx.hevc this gives me the hevc-encoded file, now I want to set a particular gop-length ...>ffmpeg -i xxx.y4m -c:v libx265 -keyint=1 -open-...
nm82
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1

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64

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Multithreading in HM reference software

Encoding an UHD sequences with HEVC HM reference software takes days on CPU’s even with monster computers, I want to know if it’s possible and then how to increase the number of threads (even if it decreases the quality of the encoding) to speed up the process (I want it to rise up to x4 times a...
Mourad
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46

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How to use an AVAssetWriter to encode HEVC (Lossless)

I'm aware that the HEVC standard supports lossless encoding, however, it appears that AVAssetWriterInput doesn't have a clear option to write hevc lossless. How do I set up the AVAssetWriterInput to write using the --lossless flag in Swift (for iOS)?
Andrew K
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42

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How to referenced frames in H264/265 decoding with AVFrame (Libav)

I am working on a project using LibAV as decoder for H264 and H265 videos. I took a decoder sample from Roxlu (http://roxlu.com/2014/039/decoding-h264-and-yuv420p-playback) as my initial point and tried to understand how things work. In my particular case, while decoding each frame, I also need to k...
fkeufss
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235

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optimize hevc_toolbox encoding to look like x265 encoding in ffmeg

I am encoding videos from h264 to h265 using ffmpeg. First I used the x265 software version for a 30 sec movie clip reducing the file size from 18Mb to 2Mb and got the following still-frame result in 45 sec Next I used the hevc_videotoolbox hardware accelerated version, first going from 18 to 1.6 Mb...
Misha
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25

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How does MP4client choose representations when playing from a local storage for a hevc-coded tile-based stream which uses SRD?

Can MP4client change the quality of each tile (select the representation of each tile) based on the viewport. If so how we determine the viewport? By moving around in the gui? Following you see how I am generating the tile-based video which I wanna play locally (so no discussion on bandwidth): kvaza...
user2034839
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What libraries i can use for decoding live stream h264 in web browser (i.e. Chrome)?

I'm still pretty new to decoding and web technology. I know there's javascript library Broadway to decode videos, is there any other libraries i can choose from? (Latency is the most important factor in my use case.) Also Broadway only supports 264, is there any libraries support HEVC/265 as well? I...
Zip
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944

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Rate Distortion Optimized Quantization

Hi i am working on HEVC standard using HM Reference code Version 10.0. Basically i am planning to RD Optimized Quantization. Theoritically we need to Minimize the Cost Function J=D+Lambda*R. My question is How we have to Estimate R before Entropy Encoding for a Particular Frame. Also Which algorithm...
1

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Parsing HEVC for Motion Information

I parsed the HEVC stream by simply identifying sart code (000001 or 00000001), and now I am looking for the motion information in the NAL payload. My goal is to calculate the percentage of the motion information in the stream. Any ideas?
user3569998
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Is there a need to apply Deblocking filter, when I have all Intra frames Encoding

I am working on H.264 Deblocking Filter and need some clarity. While designing an all Intra Encoder and Decoder, is it mandatory to add Deblocking Filter block in the Codec. If deblocking filter is not enabled for all Intra Encoding does that cause any PSNR degradation(I checked few streams the PSN...
Codec Guy
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How to write and port OpenMAX software video decoder component in stagefright media player?

I have gone through this links and few other links also, khronos OpenMax_Development_Guide bellagio_openmax_il_open_source_implementation_enables_developers_to_create but all of them just explains how the calling sequence is, picture of block diagram etc but don't explain how to write and build ope...
Mohan
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443

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Is it possible to dynamically change video encoder parameters?

I would like to know if I can dynamically change video encoder parameters for a given video? For example I would like to start encoding a raw video in H.264/H.265 for the first 10s in 30fps and then, while the encoder is still working, change the fps to 20 for the rest of it. Thanks in advance for y...
Andi Domi
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1

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507

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ffmpeg inaccurate seeking keyframes with H265 vcopy

I've got an H265 4K MP4 29.97fps video with a GOP-size of exactly 30 frames. When I try to cut from the start using : ffmpeg -ss 1 -i INPUT.MP4 -vcodec copy OUTPUT_1SEC.MP4 ffmpeg -ss 2 -i INPUT.MP4 -vcodec copy OUTPUT_2SEC.MP4 ffmpeg -ss 3 -i INPUT.MP4 -vcodec copy OUTPUT_3SEC.MP4 ffmpeg -ss 4 -i I...
dsagilles
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Is it possible to play and use HEIF/HEVC files on iOS 9 and 10?

Is it possible to play and use HEIF/HEVC files on iOS 9 and 10 using some kind of library, player or something? or is this something exclusively for iOS 11?
SpaceDog
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What's the difference between CRA picture and BLA picture?

According to HEVC spec: A clean random access (CRA) picture may have associated random access skipped leading (RASL) or random access decodable leading (RADL) pictures present in the bitstream. A broken link access (BLA) picture having nal_unit_type equal to BLA_W_LP may have associated RASL or RADL...
ravin.wang
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1

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Decoding a proprietary HEVC/MP4 stream

One of those time where I am just out of ideas and hoping for a saint. I am currently trying to decode and use a proprietary video stream of an IP cam and I feel like I am very close but I just cannot find the last piece of the puzzle. The camera is set to 1 FPS, CBR and an I-Frame interval of 1 for...
Kinsi
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2

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Modifying HEVC HM reference code

I'm very new to the field of HEVC codec. I'm using the HM reference code version 10.1. My task is to limit he CU size to 16x16. So, what i tried was in the configuration file i set the parameters MaxCUWidth, MaxCUHeight as 16 and 16 respectively. This ensures that the max CU size is limited to 16x16...
Zax
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1

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Decoding an elementary HEVC stream using ffmpeg

I have successfully compiled and installed FFMPEG_2.1 from source code. I know that ffmpeg from version 2.1 onwards supports HEVC decoder. I have generated a .bin file using HM 10.0 and HM 11.0 HEVC reference code. However, when i give this bin file as an input to the ffmpeg i get an Input/output Er...
Zax
1

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2

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489

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Introducing packet/slice loss on hevc bitstream

I'm doing a study on HEVC and very new to video compression. The first thing i want to do is see the effect of packet loss on the decoded video. I want to modify the decoder so that i can introduce packet loss on the hevc bitstream. I'll be using error patterns generated by NS2. What part of the dec...
Christopher
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1

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1.8k

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Android Media Recorder Video Encoding for HEVC(H.265) in Android

Curently I am using MediaRecorder.VideoEncoder Class for creating a HEVC(H.265) encoded video in Android. I am using Camera Class with SurfaceView for start/stop camera preview, and retrieve frames for encoding video(Recording Video). Camera mCamera = Camera.open(); mCamera.setDisplayOrientation(90...
A-Droid Tech
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Why isn't HEVC (H.265) used by smart phone apps?

I understand that there is the issue of royalty for H.265/HEVC codec but presumably that money would be paid by the smartphone manufacturer like Qualcomm for the Snapdragon. If so, why wouldn't apps like Facebook, WhatsApp, Snap use HEVC and save bandwidth, storage and other costs? I am thinking abo...
guraaf
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67

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Why the time taken by my program in MS Visual Studio 2013 in RELEASE mode in 64-bit mode is one-third of the time taken in 32-bit mode

I am running HM-16.15 encoder in RELEASE mode in Visual Studio 2013. HM-16.15 encoder is a very large C++ program (200k lines of code). I have two timings (T1 and T2). Total Time taken by program T = T1 + T2. when I build and debug the program in 64-bit mode and 32-bit mode separately. The time tak...
kcravi
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ffmpeg does not produce smooth videos from mkv h265

It's kind of subjective, but I'm not able to produce 100% smooth videos with ffmpeg. As input I use https://www.libde265.org/hevc-bitstreams/tos-1720x720-cfg01.mkv as a example.This is a h264 mkv video which is running really badly with my vlc player on my win7 laptop.Converting it to a h264 video l...
user3776738
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1

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How can I generate encoded HEVC bitstream using ffmpeg?

I am able to encoded YUV file to mp4 using HEVC: ffmpeg.exe -f rawvideo -s 1920x1080 -pix_fmt yuv420p -i input.yuv -c:v hevc -r 30 -x265-params crf=27 -vframes 300 -an -y test.mp4 Here is the mp4box -info test.mp4 shows: * Movie Info * Timescale 1000 - Duration 00:00:10.000 1 track(s) Fragmented Fi...
jgmao
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5

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Truncated rice binarization method

Based on HEVC standard, decimal quantized coefficients are binarized through different methods, e.g. Truncated Unary, Truncated Rice (k-th order), Exp-Golomb, etc. Considering the Truncated Rice method, I cannot understand the role of cmax parameter that completely changes the output. I have underst...
Alessandro
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MediaFoundation HEVC H265 encoding

I'm able to successfully encode H264 video using MediaFoundation. Now I want to export HEVC which is, according to official documentation, is supported. I am doing everything as described there but whenever I want to set input media type to the writer it ends up with an error: No suitable transform...
mbaros
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1

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1.3k

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FFMPEG providing support for HEVC decoding

FFMPEG v2.1 onwards is providing support for HEVC Decoding. I tried an elementary input bin stream as an input for it and yes i got a corresponding YUV file. Now my question is, since i'm just passing an elementary stream as an input, how is the decoder parsing it? I have gone through the /libavform...
sam
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1

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2.9k

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HEVC (h.265) intra-prediction

I am working on a project in implementing HEVC intra-prediction with MATLAB. I have read so many articles to write the codes in MATLAB and finally I have done that. (one of the most useful one was this article: Intra Coding of the HEVC Standard) The main purpose of the project is a comparison betwee...
manpmanp
2

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4

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104

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Backslash in c source file

I have follow code same as it is on different lines: frame_rate = (float) ( ( ( frames * media_timescale) + \ //WHY??? ( media_duration >> 1 ) ) / media_duration); I am not understanding what is backslash doing in source file ? Also to calculate the frame rate simply we can do as follow: frame_rat...
Mohan
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1

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750

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HEVC Quantization Parameter

The HEVC quantization(Uniform case) step in HEVC standard requires right shifting by QP/6 while calculating the level coefficients. I am not sure how to perform this right shifting for cases when QP is not divisble by 6. Any help would be appreciated. Reference: Core Transform Design in the High Ef...
Sourav Sen
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4

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4.8k

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How to decode HEVC files to YUV?

I would like to decode HEVC encoded files to YUV files. Is there any simple way to do this yet? An executable would be nice but I would make do with source code that is easily compilable.
NiRR
2

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0

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274

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Parsing and CABAC Decoder Module

Can anybody help me with Parsing & CABAC decoding engine design for HEVC. I have googled it but not getting the exact thing.
Bhavesh Upadhyay

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