High-Performance machine taking 20+ Hours to Encode AC3 audio.

[Joe Hill]

I'm currently using DVD-Flick to convert various video files to DVD Compatible VOB files.

I'm running a laptop with:
• Windows 7 Pro. (64x)
• 8GB DDR3 (2X 4GB) 1333 Mhz
- 80% free while the program is running.
• i5 Core 2.53Ghz
- Doesn't pass 3% usage while the program is running.
• Toshiba MK5056GSY: 7200 RPM about 60% full out of 450GB
- Almost entirely idle while the program is running.

The source and output are both located on the HDD.

Everything else on my computer is lightening fast, it's only when the source file utilizes AC3 audio.
Outside of AC3, a High-Quality 2 hour movie takes between 35-70 minutes.
With AC3 Quality, a 2.5 hour movie just took me 20:43:37, 19:30 of which was audio.

At this point I'm over it, and so I'm not looking for an alternative program.
I'm simply curious as to what could be the limiting factor?

The only thing I could think of is that the coding of the program itself is the limiting factor.
Which doesn't make much sense to me, I suppose I don't know enough about that bit.

I'm looking for an explanation rather than a solution.
Please don't suggest that I use any other programs.

Thanks


Format : Matroska
Format version : Version 2
File size : 706 MiB
Duration : 2h 34mn
Overall bit rate : 640 Kbps
Encoded date : UTC 2010-05-01 16:36:31
Writing application : mkvmerge v3.2.0 ('Beginnings') built on Feb 12 2010 16:46:17
Writing library : libebml v0.7.9 + libmatroska v0.8.1

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 8 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 2h 34mn
Nominal bit rate : 604 Kbps
Width : 1 280 pixels
Height : 544 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) : 0.036
Writing library : x264 core 80 r1376M 3feaec2
Encoding settings:
cabac=1 / ref=8 / deblock=1:-1:-1 / analyse=0x3:0x113 / me=umh / subme=6 / psy=1 / psy_rd=1.0:0.0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / mbaff=0 / constrained_intra=0 / bframes=3 / b_pyramid=0 / b_adapt=1 / b_bias=0 / direct=3 / wpredb=1 / wpredp=2 / keyint=250 / keyint_min=25 / scenecut=40 / rc_lookahead=40 / rc=2pass / mbtree=1 / bitrate=604 / 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
Default : Yes
Forced : No

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : HE-AAC / LC
Codec ID : A_AAC
Duration : 2h 34mn
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz / 24.0 KHz
Compression mode : Lossy
Default : Yes
Forced : No

Menu
00:00:00.097 : en:00:00:00.097

[Bjs]

Welcome Joe Hill

You need to supply information about the file in question which the issue is relevant ... use mediainfo and post those details then you might get an answer to the problem.

[jagabo]

So you're re-encoding audio from something else to 5.1 AC3? What is that "something else"?

[Joe Hill]

So you're re-encoding audio from something else to 5.1 AC3? What is that "something else"?

I'm remuxing various video files using AC3 for audio to VOB.
Including:
MKV
AVI
DivX
Mv4
Xvid
The list goes on..

[jagabo]

Please try writing what you mean. You still haven't said if you're encoding AC3 or remuxing AC3.

[Joe Hill]

Welcome Joe Hill

You need to supply information about the file in question which the issue is relevant ... use mediainfo and post those details then you might get an answer to the problem.

Thanks, I'm brand new to audio/video editing.

[Joe Hill]

Please try writing what you mean. You still haven't said if you're encoding AC3 or remuxing AC3.

Remuxing

[Joe Hill]

K guys this is going to sound really weird, but I just opened up a second instance of DVD flick,
(Figuring that since <10% of my resources are being used I could just do like 5 at a time)

And the conversion process instantly went from 1% per 2 minutes to 100% in about a minute.

I just tried it with the same 20 hours file as before and it converted the entire 2.5 hour movie in 12 minutes.

WTF?

Also the quality of audio and video between the two are identical.


I just rebooted and tried it again.
One instance open: 1%...(2 minutes) 2%......... 3%............
Two instances (1 idle): 3%..18%..36%...60%...99%..100%

[jagabo]

Very odd. Clearly some kind of software problem. Maybe a version issue with some other software (file reader, splitter, muxer) you have installed?

I know of one program (Divx codec) that has the opposite problem. It can't use all the cores effectively so I tried running two instances. But each instance then slowed down to 1/100th the speed of the single instance. It wasn't disk thrashing or VM problem. It had something to do with the locks within the encoder.

[Joe Hill]

Yea I could have muffed up some codecs along the way to finding a decent program, I tried 10 or 12 before settling with DVD Flick. I'll probably just uninstall everything and do a fresh install of DVD-Flick.

Thanks.

I'm doing 2 at a time now and some take 20 minutes, and some take about 80 minutes tops.

No more 20 hours