[MEncoder-users] Mencoder - Differences between using libc for DVD access and Win2K API

[Nigel Arnold]

Hello All

I've been doing some speed tests with mencoder and found this, which i think 
is quite incredible and I'm open to any comments/thoughts/insights as to why 
it may happen.

Mencoder build is 25513 provided by Sherpya and therefore is Win32

My simple command line is

mencoder.exe dvd://2 -dvd-device D:\  -Chapter 03-03  -of lavf -lavfopts 
format=mp4 -oac lavc -ovc lavc -lavcopts 
aglobal=1:vglobal=1:vcodec=mpeg4:acodec=libfaac:vbitrate=1500:abitrate=128:threads=8 
 -vf scale=720:-10,harddup -ofps 25 -o "Test.mp4"

I get about 45 fps speed encoding, with the above

However, If i change the -dvd-device to D:\VIDEO_TS instead of D:\

mencoder.exe dvd://2 -dvd-device D:\VIDEO_TS  -Chapter 03-03  -of 
lavf -lavfopts format=mp4 -oac lavc -ovc lavc -lavcopts 
aglobal=1:vglobal=1:vcodec=mpeg4:acodec=libfaac:vbitrate=1500:abitrate=128:threads=8 
 -vf scale=720:-10,harddup -ofps 25 -o "Test.mp4"

I get a massive 150fps and it obviously takes a fraction of time to encode. 
This is HUGE speed increase

So here is my question, WHY so slow when using D:\ and so fast when using 
D:\VIDEO_TS

The only thing i've found is this

If i set the ENV variable DVDCSS_VERBOSE to 2, to enable the CSS messages on 
stderr and stdoutput, I can see the following

When using D:\ as the -dvd-device
MEncoder Sherpya-SVN-r25513-4.2.2 (C) 2000-2007 MPlayer Team
CPU: Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz (Family: 6, Model: 15, 
Step
ping: 11)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
libdvdcss debug: opening target `d:\'
libdvdcss debug: using Win2K API for access                            <<< 
This is the main difference that i can see
libdvdcss debug: disc is scrambled
libdvdcss debug: requesting AGID
libdvdcss debug: drive authenticated, using variant 0
libdvdcss debug: authentication established
libdvdcss debug: GetASF authenticated, ASF=1
libdvdcss debug: decrypting disc key a2:ee:d9:3a:64
libdvdcss debug: trying player key 01:af:e3:12:80
libdvdcss debug: decrypted disc key is 2e:97:32:1f:24
libdvdcss debug: using CSS key cache dir: C:\Documents and 
Settings\xxxxxx/.dvdcss/MP725D-2007022113200800-2e97321f24/


When using D:\VIDEO_TS as the -dvd-device
libdvdcss debug: opening target `d:\video_ts'
libdvdcss debug: using libc for access
There are 21 titles on this DVD.
There are 12 chapters in this DVD title.
There are 1 angles in this DVD title.
libdvdcss debug: opening target `d:\video_ts/VTS_02_0.IFO'
libdvdcss debug: using libc for access
libdvdcss debug: using CSS key cache dir: C:\Documents and 
Settings\xxxxx/.dvdcss/-00cf6c0000d03300-0000000000/
libdvdcss debug: opening target `d:\video_ts/VTS_02_1.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: successful attempts 1/1, scrambled blocks 37/38
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02
libdvdcss debug: opening target `d:\video_ts/VTS_02_2.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: successful attempts 1/1, scrambled blocks 766/2477
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02
libdvdcss debug: opening target `d:\video_ts/VTS_02_3.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: successful attempts 1/1, scrambled blocks 474/1426
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02
libdvdcss debug: opening target `d:\video_ts/VTS_02_4.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: at block 4096, still cracking...
libdvdcss debug: at block 8192, still cracking...
libdvdcss debug: at block 12288, still cracking...
libdvdcss debug: at block 16384, still cracking...
libdvdcss debug: successful attempts 1/1, scrambled blocks 5076/17439
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02
libdvdcss debug: opening target `d:\video_ts/VTS_02_5.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: at block 4096, still cracking...
libdvdcss debug: at block 8192, still cracking...
libdvdcss debug: at block 12288, still cracking...
libdvdcss debug: at block 16384, still cracking...
libdvdcss debug: at block 20480, still cracking...
libdvdcss debug: at block 24576, still cracking...
libdvdcss debug: successful attempts 1/1, scrambled blocks 5017/26209
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02
libdvdcss debug: opening target `d:\video_ts/VTS_02_6.VOB'
libdvdcss debug: using libc for access
libdvdcss debug: cracking title key at block 0
libdvdcss debug: at block 4096, still cracking...
libdvdcss debug: at block 8192, still cracking...
libdvdcss debug: at block 12288, still cracking...
libdvdcss debug: at block 16384, still cracking...
libdvdcss debug: at block 20480, still cracking...
libdvdcss debug: at block 24576, still cracking...
libdvdcss debug: at block 28672, still cracking...
libdvdcss debug: at block 32768, still cracking...
libdvdcss debug: successful attempts 1/1, scrambled blocks 10978/35566
libdvdcss debug: vts key initialized
libdvdcss debug: title key is c0:00:00:00:02


Any comments, thoughts, is this normal ?

Thanks

N