Welcome to HEVC thread

In february 2015 the availability of open source HEVC codec (High Efficiency Video Compression, known also as h265) means it is ready to be used by all us.

To read/download the standard reach the ITU website and select the latest available version (as of writing, on may 23rd, the latest release of april 2015 was still not available). All the ITU standards are downloadable for free in pdf format. It is extremely valuable that standards are made public at no cost. For media industries the most known are h262 (mpeg2) and h264 (avc). Please consider how all the international bodies that sell the standards damage the interoperability and the progress of technology, forbidding an easy access the reference documents to the interested audience.

The more than 500 pages of the h265 standard may be too complex at first sight.
For basic informations you may read these Wikipedia articles about the h265 standard or its tiers and levels (the profiles and levels of former MPEG standards).

Yes, Wikipedia, please do not be disturbed! I think that the lack of simple and accessible information is one reason of the wide technology misconceptions, too much limited to a restricted public. All the things available over the web requires knowledge to be filtered out from dust and mistakes.
Wikipedia - one of the greatest things available on the web, I think - may back the first steps (and often the further ones) of this knowledge gain.

My voice

I remember in 1989 when the first MPEG1 standard papers comes out. A plenty of time passed by, but we must not forget it has been the first brick (even a stone: think to mp3 success!) that affected the technology of media as never before.

I was in.

And today, being HEVC an hot subject, I've not been able to refrain me from writing down something:

embedded 360p24 HEVC embedded html page (february 2015)
It requires videolan VLC player version 2.2.0 (or greater) to be decoded. VLC is available in LGPL from videolan website.
Video embedding is not performed on smartphones for which browsers plug-ins have not been released (and probably will never done).
Smartphones - after installing VLC for android of iOS - may access to the stream http://www.iginomanfre.it/x70_hevc_300

embedded 720p24 HEVC embedded html page (february 2015)
This reproduction requires an hardware base with at least powerful as a Core2duo or a quadricore ARM on http://www.iginomanfre.it/x70_hevc_1200

Before (CPU load at 15%) and after starting the 1.2 Mbps 720p24 stream reproduction on my core2duo laptop

A couple of months after considerations (may 2015)

Further consideration of November 2015

Other things are coming, 4k (4:2:0) with source downloaded from the web... but the time to compress them on my small core2duo is terrible.
Not only, but in july 2015 VLC stopped to compress in hevc with x265 library.
No problem, I can use ffmpeg, the open source software which developed the library. But there are few problems about which I'm investigating, not only the speed.

A lot of passes have been done...

I remember in 1993-95, to compress in AVI CIF with Radius Cinepack codec or the Intel Indeo 3.2 compressors from a PAL signal precropped to CIF or smaller: running on a 486 or one of the first pentium based pcs (the maximum available at the time) it required an entire day (23 hours) and the output quality was very poor if compared to today's codecs. The audio has been compressed in linear PCM with a sampling rate of 11025 KHz because at that time mpeg 1 layer 2 -- already available at that time -- was correctly played only by dedicated hardware.

If you want you may download to play a small video (the "credits", the people that worked on Multimedia 2 go), 2 minutes long I've found on the original CD we made, compressed in Intel Indeo 3.2 (19.6 MB), in current h264 with mp3 audio (about 3.2 MB) and current h264 with aac audio (about 2.4 MB).
Expecially the first version, a quite big file, compressed with a very old codec, could be reproduced only by VLC (despite it should be playable by default by Windows), and in any case could be good to download it before through the right mouse click and "save as".
When I tested this page, I remained quite surprised to see that the entire 2 minute video, compressed in h264, was played immediately by mozilla firefox, not - as I though through VLC after it had been choosed as default opener of mp4 files - but by the browser itself in a way required by HTML5 compliancy.
It is all but a curious note: it is a big problem of html5 compliancy, as it has been interpreted by Google Chrome, is the management of video compressions that cannot be external through plug-ins, but must be performed by the browser itself.
Mobile phones' browser do not use plug-ins but workstations ones used to did it. New releases of Chrome don't.

Comparisons between the three version of the same video (mediainfo)
:
General
FilenameH:\video\Multimedia 2 Go people (19950222).aviH:\video\Multimedia 2 Go people (19950222)_a.mp4H:\video\Multimedia 2 Go people (19950222)_e.avi
FormatAVI, Audio Video Interleave, recMPEG-4, Base Media, isomMPEG-4, Base Media, isom
File size19.1 MiB3.16 MiB2.38 MiB
Duration2mn 7s2mn 7s2mn 7s
Overall bit rate1 257 Kbps208 Kbps157 Kbps
Video
ID011
Format, Codec, Version/Profile/LevelIndeo 3, IV32, Intel Indeo Video 3.2AVC, Advanced Video Coding, High@L1.3AVC, Advanced Video Coding, High@L1.3
DetailsCABAC, Reframes=4CABAC, Reframes=4
Width, Display Aspect Ratio, Frame Rate320x240, 4:3, 25 fps320x240, 4:3, 25 fps320x240, 4:3, 25 fps
Frame Rate25 fpsvariable: mean 24.247 fps, min 6.250 fps, max 25.000 fpsvariable: mean 24.247 fps, min 6.250 fps, max 25.000 fps
Bits/(Pixel*Frame)0.5730.0810.054
Color space, Chroma subsampling, Bit Depth, ScanY'UV, 4:2:0, ProgressiveYUV, 4:2:0, 8bit, ProgressiveYUV, 4:2:0, 8bit, Progressive
Stream size16.8 MiB (88%)2.22 MiB (70%)1.48 MiB (62%)
Writing Libraryx264 core 146 r2538 121396cx264 core 146 r2538 121396c
Detailscabac=1, ref=3, deblock=1:0:0, analyse=0x3:0x133, me=hex, subme=7, psy=1, psy_rd=1.00:0.00, mixed_ref=1, me_range=16, chroma_me=1, trellis=1, 8x8dct=1, cqm=0, deadzone=21,11, fast_pskip=1, chroma_qp_offset=-2, threads=3, lookahead_threads=1, sliced_threads=0, nr=0, decimate=1, interlaced=0, bluray_compat=0, constrained_intra=0, bframes=3, b_pyramid=2, b_adapt=1, b_bias=0, direct=1, weightb=1, open_gop=0, weightp=2, keyint=250, keyint_min=25, scenecut=40, intra_refresh=0, rc_lookahead=40, rc=2pass, mbtree=1, bitrate=150, ratetol=1.0, qcomp=0.60, qpmin=10, qpmax=51, qpstep=4, cplxblur=20.0, qblur=0.5, ip_ratio=1.40, aq=1:1.00
Audio
ID122
Format, Endianness, Sign, Codec IDPCM, Little, Unsigned, 1MPEG Audio, Version 1, Layer 3, 6BAAC (lav), Advanced Audio Codec LC, 40
Bitrate88.2 Kbps56.0 Kbps50.8 Kbps (max 56 Kbps)
Bitrate mode, Sampling rate, channelsConstant, 11.025 KHz, 1 channelConstant, 48.0 KHz, 2 channelsConstant, 48.0 KHz, 2 channels
Alignement, interleave durationAligned on interleaves, 40 ms (1.00 video frame)
Stream Size1.34 MiB (7%)872 KiB (27%)791 KiB (32%)


back