HEVC Balanced Tiling
HEVC supports non-uniform (or arbitrary) tiling. Therefore encoder should adapt tiling grid in order to minimize the decoding time. Bitsizes of all tiles are expected to be nearly equal each to other. Otherwise, the decoding process can be imbalanced ( if multiple threads are applied to decode tiles simultaneously then small sized tiles are finished […]
Why is there no evidence of civilizations prior to about 12,000 years ago?
Why is there no evidence of civilizations prior to about 12,000 years ago, despite Homo Sapiens having been around since 200,000 to 300,000 years ago? Most archeologists suppose that the reason for lack of civilizations before 12,000 years ago is that unfavorable climate which prevented people from forming civilizations. Homo Sapiens have been around since […]
SSIM and MS-SSIM Codes
C++ version of SSIM is available at https://github.com/utlive/ConsoleSSIM.git . Notice that to build this code by Visual Studio you need to install MFC. The code was developed by Laboratory for Image and Video Engineering at the University of Texas at Austin (a trustful source) The exe-file (conSSIM.exe) accepts only jpg-files are input (an annoying restriction). […]
Correlation of different metrics (video quality models) with subjective quality assessment (DMOS)
Taken from the paper “Study of Subjective and Objective Quality Assessment of Video”, Kalpana Seshadrinathan et al. Notes: The paper was published at 2009, prior to VMAF developed Good HVS-correlated metrics (like MOVIE) are unable to provide real-time measurement of video quality, since they are too complex. DMOS = MOS_pristine – MOS_compressed […]
Leading Pictures in VVC and HEVC
Both HEVC and VVC can contain so-called leading pictures “around” a key frame. The leading pictures definition: to follow the key frame in decoding order but to precede it in output order. Definition: Random access means the ability to start consuming or playing video content from positions other than the very beginning of the bitstream. […]
AVIF Image Format
AVIF image format is a new emerging format to contain AV1 images (like HEIF for HEVC/H.265). The spec. of AVIF format . Notice that AVIF format is based on AV1 intra encoded images. Recently it was declared that Safari 16.0 for iOS 16 supported AVIF image format. In the recent version of ffmpeg (ffmpeg version […]
VVenC Open Source Implementation of VVC Codec
VVEnC How get VVEnC? How Build VVEnC in Windows? How Run VVEnC? VVDec How get VVDec? How Build VVDec in Windows? How Run VVDec? Appendix: Subjective Comparison between HEVC and VVC Appendix: Objective Comparison between HEVC and VVC Appendix: Objective Comparison between VVenC and other codecs Appendix: Use Case – Percentage of Partitions Appendix: Multiple […]
Which codecs does YouTube use (based on Jan Ozer’s analysis)?
This paper is based on Jan Ozer‘s analysis. 1) For less 1080p resolutions, YouTube selects the codec according to view count: AV1 for videos with view counts above half-million VP9 for videos with view counts from several thousands to half-million H264 for low view counts (less several thousands) Notice that hevc is not used by […]
Bento4 Tool – Free Programs to Process Video/Audio Streams
Content Conversion regular mp4-file into the fragmented Parsing mp4-file metadata with mp4dump Extract single box from mp4-file with mp4extract Removal atoms from mp4-file with mp4edit Encryption: mp4encrypt and mp4decrypt Representation mp4 metadata tables in more compact form (squeeze) How Create and Build Bento4 Visual Studio Solution Download binaries (for all platforms): https://www.bento4.com/downloads/ Documentation: […]
Hawking Radiation
Stephen Hawking found that quantum fields are disturbed in the proximity of the event horizon of a black hole. Quantum fluctuations in vacuum always produce virtual entangled particle-antiparticle pairs which are quickly annihilated in order to pay the energy back to the Universe (otherwise the law of Energy Conservation is violated, it’s actually violated but […]