H264 Profile High@4.1 with 5 Ref Frames?!

[Eudorcas]

General
Format : Matroska
Format version : Version 1
File size : 8.16 GiB
Duration : 1h 54mn
Overall bit rate : 10.2 Mbps
Encoded date : UTC 2011-08-27 06:23:04
Writing application : mkvmerge v2.3.0 ('Freak U') built on Sep 8 2008 18:32:16
Writing library : libebml v0.7.7 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 54mn
Bit rate : 8 020 Kbps
Width : 1 920 pixels
Height : 816 pixels
Display aspect ratio : 2.35:1
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.214
Stream size : 6.27 GiB (77%)
Writing library : x264 core 116 r2074 2641b9e
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=8 / 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=0 / chroma_qp_offset=-2 / threads=18 / 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=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=8020 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:1.00
Language : English
Default : Yes
Forced : No

Audio #1
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : ES
Codec ID : A_DTS
Duration : 1h 54mn
Bit rate mode : Constant
Bit rate : 1 510 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.21 GiB (15%)
Title : DTS
Language : English
Default : Yes
Forced : No

Audio #2
ID : 3
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 1h 54mn
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 526 MiB (6%)
Title : DD5.1
Language : English
Default : No
Forced : No

Text #1
ID : 4
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : Nederlands SRT
Language : Dutch
Default : Yes
Forced : No

Text #2
ID : 5
Format : UTF-8
Codec ID : S_TEXT/UTF8
Codec ID/Info : UTF-8 Plain Text
Title : english
Language : English
Default : No
Forced : No

Is it actually possible to encode High 4.1 with 5 Ref Frames? 4.1 is restricted max ref of 4.

If I'm right, 8388608 / (1920*1080) = 4.05 ~ 4 ref.

[Slipster]

Is it actually possible to encode High 4.1 with 5 Ref Frames?

Yes.

4.1 is restricted max ref of 4.

Is it?

[jman98]

I'm not going to tell you that I spent a long time on the subject, but I can't find a reference that says that 4.1 is restricted to 4 reference frames. Maybe you are confusing the fact that some standalone players can't play more than 4 reference frames and can't work with video above 4.1 and making the wrong conclusion that 4.1 can't have more than 4 reference frames.

[intracube]

Looks like the number of ref. frames depends in part on the resolution:
http://doom10.org/index.php?topic=69.0
"In Level 4.1 H.264 allows 9 reference frames for 720p and 4 reference frames for 1080p"

and:
http://forum.doom9.org/archive/index.php/t-100356.html
http://forum.doom9.org/showthread.php?p=621038#post621038

[Eudorcas]

I know as much as that, but why encode in 4.1 just to break the restriction or rule if it's also possible to just encode in unrestricted and go all out (up to 16 ref). I believe profile levels are meant to restrict the x264 settings to a certain level for it's compatibility to standalone players, it serves as a mark. Is it just to cheat the standalone player of some sort?

Looks like the number of ref. frames depends in part on the resolution:
http://doom10.org/index.php?topic=69.0
"In Level 4.1 H.264 allows 9 reference frames for 720p and 4 reference frames for 1080p"

and:
http://forum.doom9.org/archive/index.php/t-100356.html
http://forum.doom9.org/showthread.php?p=621038#post621038

Yeah, already red that and it's all over wiki as well. Thanks.

But how about this w/o any crops or black bars in full 1920x1080 (16:9) with 5 Ref.

General
Unique ID : 211413123791290144127504225877586125065 (0x9F0CAFC35A847331A9DE6B70DEB0A109)
Complete name : D:\Kara.Best.Clip.II.Show.2011.BluRay.EP03.Back.St age.&.Making.Live.at.YOKOHAMA.ARENA.1080p.AC3.x264-HDS.mkv
Format : Matroska
Format version : Version 2
File size : 1.51 GiB
Duration : 23mn 48s
Overall bit rate : 9 086 Kbps
Encoded date : UTC 2012-04-05 17:53:28
Writing application : mkvmerge v5.4.0 ('Piper') built on Mar 10 2012 13:34:39
Writing library : libebml v1.2.3 + libmatroska v1.3.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 23mn 48s
Bit rate : 8 730 Kbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.140
Stream size : 1.41 GiB (93%)
Writing library : x264 core 120 r2164 da19765
Encoding settings : cabac=1 / ref=5 / deblock=1:-3:-3 / analyse=0x3:0x113 / me=umh / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=20 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=24 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=2pass / mbtree=1 / bitrate=8730 / ratetol=1.0 / qcomp=0.70 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv_maxrate=14000 / vbv_bufsize=14000 / nal_hrd=none / ip_ratio=1.40 / aq=1:1.00
Language : English
Default : Yes
Forced : No

Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 23mn 48s
Bit rate mode : Constant
Bit rate : 448 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 76.3 MiB (5%)
Default : Yes
Forced : No

[jagabo]

Anyone can change the profile flag to anything they want with an profile editor. Maybe it wasn't encoded at 4.1 but someone changed the flag later so their Blu-ray player would play it.