Encoding with FFmpeg / x264: High 10 Profile (Hi10P)

[andrew.46]

University vacation is upon me so I have been investigating using FFmpeg to encode using High 10 Profile (Hi10P) which I believe is pretty big in the anime world but has not spread much further. I am interested to hear if anybody has been using it or if there can be any suggestions made of the technique I have used?

First step was to recompile x264 with the --bit-depth=10 option, perhaps easiest Ubuntu method is follow FakeOutdoorsman's great guide (http://ubuntuforums.org/showthread.php?t=786095) and simply add this option in to the ./configure string given for x264. Next pull out my favourite scene from the Matrix:



tccat -i /dev/dvd -T 1,15,1 > fight.vob


and then pull out the audio and convert to aac:



ffmpeg -i fight.vob -ac 2 -ar 44100 -vn -f wav - | \
neroAacEnc -ignorelength -q 0.65 -if - -of audio.mp4


The video processing is the one I am not so sure about, so I would welcome suggestions here:



ffmpeg -i fight.vob -an \
-vcodec libx264 -preset veryslow -tune film -profile high10 \
-crf 24 -vf crop=720:416:0:80 \
video.mp4


The cropping is simply to take out the black bars from top and bottom. Note the slightly higher than usual crf value which I believe is recommended for h10 encoding. I then mux with mkvmerge:



mkvmerge --title "Matrix sparring scene" -o matrix_sparring_h10.mkv \
--track-name 1:"Encoded with x264 High 10 Profile (Hi10P)" \
--language 1:eng --default-track 1:yes video.mp4 \
--track-name 1:"Encoded with neroAacEnc 1.5.4.0" \
--language 1:eng --default-track 1:yes audio.mp4

The final result is here:



wget http://www.andrews-corner.org/tmp/matrix_sparring_h10.mkv


I would value any comments on the technique I have used and the quality of the output clip, plus any comments on the so-called 'high 10' profile in x264. Mediainfo shows the following on this output file:



andrew@skamandros~/media/matrix$ mediainfo matrix_sparring_h10.mkv
General
Unique ID : 14829788043047948209532235037227713355 (0xB281D005167F7A3F5DF8B84E31D834B)
Complete name : matrix_sparring_h10.mkv
Format : Matroska
Format version : Version 2
File size : 23.7 MiB
Duration : 4mn 22s
Overall bit rate : 757 Kbps
Movie name : Matrix sparring scene
Encoded date : UTC 2011-11-05 20:57:30
Writing application : mkvmerge v5.0.1 ('Es ist Sommer') built on Oct 10 2011 19:36:05
Writing library : libebml v1.2.2 + libmatroska v1.3.0

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High 10@L3.2
Format settings, CABAC : Yes
Format settings, ReFrames : 16 frames
Muxing mode : Header stripping
Codec ID : V_MPEG4/ISO/AVC
Duration : 4mn 22s
Width : 720 pixels
Height : 416 pixels
Display aspect ratio : 2.462
Frame rate mode : Variable
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Scan type : Progressive
Title : Encoded with x264 High 10 Profile (Hi10P)
Writing library : x264 core 119 r2106 07efeb4
Encoding settings : cabac=1 / ref=16 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-3 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=8 / 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=60 / rc=crf / mbtree=1 / crf=24.0 / qcomp=0.60 / qpmin=0 / qpmax=81 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language : English

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 4mn 22s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Compression mode : Lossy
Title : Encoded with neroAacEnc 1.5.4.0
Language : English

Menu
00:00:00.059 : en:00:00:00.059

[kd7lxl]

First step was to recompile x264 with the --bit-depth=10 option, perhaps easiest Ubuntu method is follow FakeOutdoorsman's great guide (http://ubuntuforums.org/showthread.php?t=786095) and simply add this option in to the ./configure string given for x264.



ffmpeg -i fight.vob -an \
-vcodec libx264 -preset veryslow -tune film -profile high10 \
-crf 24 -vf crop=720:416:0:80 \
video.mp4Does compiling this way replace an existing 8-bit-depth libx264, or do they coexist? I see you are instructing ffmpeg to use Hi10P. I would like 8-bit-depth and 10-bit-depth installations of libx264 to coexist, so I can choose which bit-depth to use at runtime. It's not clear if this is possible with your installation.

[andrew.46]

I believe that with x264 it is a case of using one or the other, but I am ready to be corrected.... I will investigate a little further.

[kd7lxl]

Hmm, that's what I was afraid of. Maybe I can hint which version of the library I want to use with LD_LIBRARY_PATH.

Did you have to recompile ffmpeg after you rebuilt libx264? I'm still thinking there's got to be a way to juggle two versions of libx264 and choose one at runtime.

[andrew.46]

I certainly recompiled FFmpeg.