MKV L5.1 to 4.1 revisited

[realrisk2]

Hi guys, in another thread - I doubt if anybody is still interested in it - I posted my findings about the 'conversion' of MKV L5.1 to L4.1. That post was a premature ejaculation because I forgot to test my findings on my Asus media player (yes, I know, how stupid can one be, since my problem was with the media player(s) not be able to handle L5.1 in the first place).

Okay, I experimented with an extracted part (10%, 350 MB split in mkvmerge) of the video file. I first used the cheap routes to changing to L4.1 by use of tsmuxer or h264leveleditor but - as the video guru's stated - that would only work for 'false' L5.1's... Anyway these easy routes didn't fool my media player.
So I followed the longer route of mkvextractgui 2, extracting 3 files: video, audio and subtitles. Then I opened up h264info and changed the level of the extracted video file to 4.1. That wasn't enough though because I immediately got the message: 'PTS < DTS! Rerun...' so I checked the b-pyramid option as well (in one of my trials I even typed in '4' for reference frames) and I got a new.264 file. I opened up mkvmerge and remuxed this new.264 file with the audio and subtitle file. Result: no video, only audio. Mkvmerge issued a warning though: It could not determine TimeCode and the result could be unplayable (and while remuxing mkvmerge showed the three partfiles as Id0). In the end I got a video file that was unplayable and Mediainfo showed Format profile: Unknown@L8.5 !

So I took the longest route: re encoding with Handbrake (Profile High). It took my quadcore about 30 min to convert the 350MB file and I ended up with a playable (250MB) video file with an overall bit rate of 7655 (far less than the original file: 13.400) and of course an unattractive picture. The most alarming thing though was that during the conversion process ProcessLasso indicated that my processor was working almost continiously at 100 percent.
I assume this can't be good at all, since if I would like to re encode the whole file of 4.5 Gig at twice the bit rate (for a better picture), how long would this take and how damaging would this be for the processor!

Anybody any idea where I went wrong?

[Selur]

how damaging would this be for the processor!

if your processor has a problem with running at 100% your system probably has temperature problems

Anybody any idea where I went wrong?

probably nowhere,...

[El Heggunte]

Just FYI --- there are no such things as "MKV Level 5.1" and "MKV Level 4.1".

Matroska is a media container, whereas H.264 is a video compression "method".

Precise terminology does matter.

[jagabo]

A properly cooled system can run at 100 percent CPU usage indefinitely. You usually want to use 100 percent of the CPU while encoding. If you want to use the computer for other things while encoding just set the priority of the encoder to low. You'll hardly notice it's running in the background.

If your computer can't run at 100 percent indefinitely (ie, it overheats or the PSU flakes out) you should take it back to where you got it and demand a refund.

[realrisk2]

Thanks.
That answers my question of 100% processor speed: I don't have to worry.
And thanks El Heggunte for your comment. Any precise solutions for changing the H.264 L5.1 compression?
Since extracting and remuxing didn't work, anybody for the accurate Handbrake parameters to stay as close as possible to the original video file?:

Earth (2006) 3 Doc BBC\New folder (2)\Planet.Earth.02.Mountains.2006.1080p.HDDVD.x26 4-AJP.mkv
Format : Matroska
Format version : Version 1
File size : 4.37 GiB
Duration : 49mn 56s
Overall bit rate : 12.5 Mbps
Encoded date : UTC 2007-05-14 13:19:19
Writing application : mkvmerge v2.0.2 ('You're My Flame') built on Feb 21 2007 23:40:55
Writing library : libebml v0.7.7 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 16 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 49mn 56s
Bit rate : 12.1 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.243
Stream size : 4.13 GiB (94%)
Writing library : x264 core 55 svn-655
Encoding settings : cabac=1 / ref=16 / deblock=1:-2:-1 / analyse=0x3:0x133 / me=umh / subme=7 / brdo=1 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=0 / threads=2 / nr=0 / decimate=0 / mbaff=0 / bframes=3 / b_pyramid=1 / b_adapt=1 / b_bias=0 / direct=3 / wpredb=1 / bime=1 / keyint=250 / keyint_min=25 / scenecut=40(pre) / rc=2pass / bitrate=12087 / ratetol=1.5 / rceq='blurCplx^(1-qComp)' / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30
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 : 49mn 56s
Bit rate mode : Constant
Bit rate : 448 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 : 160 MiB (4%)
Title : English (AC3)
Language : English
Default : Yes
Forced : No

Text
ID : 3
Format : ASS
Codec ID : S_TEXT/ASS
Codec ID/Info : Advanced Sub Station Alpha
Compression mode : Lossless
Language : English
Default : Yes
Forced : No