[RESOLVED] DGAvcDecDI crashes when playing mkv-file

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prokhozhijj
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Joined: Sat Jan 01, 2011 11:16 am

Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

I am not lecturing you. I'm just voicing my thoughts aloud. Also I clearly see the difference of CPU utilization between DGSource and DSS2 in my script. You can easily check that I am right. Just use Microsoft Process Explorer tool. It can show how many threads actually in use within one application process and what the nature of these threads.

I am amateur in video standards. It is true. But I am not amateur in system administration - in this area I am professional. And I know difference between multi-processing, multi-threading and multi-coring. I'm sorry if my knowledge in this area hurt you.

Please show me example of video processing script for Avisynth, when CPU utilization with DGSource will be equal to 100%. Because until now I can't understand how to reach it with DGSource. However I can easily do it with DSS2. All my scripts have been given already to you.
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

I do not get crashing when I put SetMTMode(5,0) before DGSource(). If you do, perhaps you should remove all that MV tools stuff and see if it still crashes. If so, then please use your awesome system administration skills to provide me with a Dr. Watson dump of the crash.
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prokhozhijj
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Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

There is a dump.

http://www.filefactory.com/file/b4g7c95/n/x264.zip
MD5: 5B24798EFD065F78523CA09F45308FD4
Size: 19'002'233

Avisynth script:

Code: Select all

SetMemoryMax(2000)
SetMTmode(5,0)
LoadPlugin("D:\arh\media\edit\video\_Filters\DGAVCDecDI\2025_20110106\DGAVCDecodeDI.dll")
DGSource("g:\video1.dgi")
return last
I've removed any dll-s from Avisynth plugins folder except for following:

DirectShowSource
MT
TCPDeliver
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

What is x264.DMP and how do I view it?

DrWatson logs are *.wlg.
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prokhozhijj
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Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

I've made this dump with Windows Task Manager. It can can be viewed with Windows debugger which comes with Windows SDK 7.
As far as I know there is no Dr.Watson debugger in Windows 7. But maybe I am wrong and you can tell me how I can run it in Windows 7.

Also I have diagnostic message from OS. I don't know if it could help... It looks like following

Event name: APPCRASH
Application name: x264.exe
Application version: 0.0.0.0
Application timestamp: 4d08623f
Module name: DGAVCDecodeDI.dll
Module version: 0.0.0.2025
Module timestamp: 4d2542b7
Exception code: c0000005
Exception offset: 000057c5
OS version: 6.1.7600.2.0.0.256.1
Language code: 1049
Additional info 1: 0a9e
Additional info 2: 0a9e372d3b4ad19135b953a78882e789
Additional info 3: 0a9e
Additional info 4: 0a9e372d3b4ad19135b953a78882e789
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

Sorry I do not currently have Win7.

Can't you provide a text dump?

Also, what happens with your script if you just load it into VirtualDub and play it?
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prokhozhijj
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Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

admin wrote: Can't you provide a text dump?
How it can be done? I'll do it, of course.
admin wrote: Also, what happens with your script if you just load it into VirtualDub and play it?

It crashes in very beginning. I've attached text file with crash info.
Attachments
crashinfo.zip
(2.03 KiB) Downloaded 675 times
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

That's strange because you say it crashes at the beginning but the dump shows decoder_flush() in the call stack and that is not called until end of stream.

Can you test on a WinXP SP3 system?

I plan to install Win7 soon on my old machine. I will test there when it is done.
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prokhozhijj
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Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

admin wrote:That's strange because you say it crashes at the beginning but the dump shows decoder_flush() in the call stack and that is not called until end of stream.
I have no time to notice any video when it crashes.
admin wrote: Can you test on a WinXP SP3 system?
I can try under virtual machine only. But I don't think that it will be relevant testing because of different hardware list that virtual machine has. If you count that it will be useful than I'll try without any doubt.
admin wrote: I plan to install Win7 soon on my old machine. I will test there when it is done.
Of course, I can wait until you install new OS. There is no any hurry. Just let me know about this event, please.
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

prokhozhijj wrote:Of course, I can wait until you install new OS. There is no any hurry. Just let me know about this event, please.
I'm installing Win7 on one of my rigs right now. It may take me some time to get DiAVC installed and registered, etc.
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

OK, I have some results for you. I have Win7 running on an E8500 dual core. Comments follow the results.

Test 1: No MT
----------------

loadplugin("D:\DGAVCDecDI\DGAVCDecodeDI.dll")
DGSource("00271.dgi")
Tweak(sat=0.0)
assumefps(5000) # to make VirtualDub play at maximum possible rate

Playing in VirtualDub gives 23.4 fps @ 100% CPU.

Test 2: SetMTMode(2,0) at top of script
-----------------------------------------------

SetMTMode(2,0)
loadplugin("D:\DGAVCDecDI\DGAVCDecodeDI.dll")
DGSource("00271.dgi")
Tweak(sat=0.0)
assumefps(5000) # to make VirtualDub play at maximum possible rate

Playing in VirtualDub gives 17.9 fps @ 100% CPU.

Test 3: SetMTMode(5,0) and SetMTMode(2,0)
-----------------------------------------------------

SetMTMode(5,0)
loadplugin("D:\DGAVCDecDI\DGAVCDecodeDI.dll")
DGSource("00271.dgi")
SetMTMode(2,0)
Tweak(sat=0.0)
assumefps(5000)

Playing in VirtualDub gives 3.2 fps @ 100% CPU. The MT documentation warns that SetMTMode(5,0) is very slow. Here you can see it.

Comments
------------

When the filters accessing the source filter are multithreaded, then the filter will receive nonlinear (not monotonically increasing) frame number requests. This will lead to poor performance due to random access being invoked. You can see it in the results. If you must have multithreading, then you can *try* the Test 2 setup and hope that the multithreading in the remainder of the script makes up for the loss due to random accesses in the source filter.

Note that I also ran Tests 1 and 3 on my fast WinXP machine at the stream's display rate of 23.976. With no threading (Test 1) I got about 13% CPU utilization. With threading as in Test 3, the CPU utilization went to 100% but the frame rate was radically degraded, just as shown above for the Win7 machine. The MT support page clearly warns about not optimizing for CPU utilization but rather for rendering rate. Now it's clear to me that that warning is spot on.

Finally, at no time did I ever experience any crashes during this testing. If you are seeing crashes then in the absence of any other people reporting it I have to assume you have some system-specific problem.

I don't know what more I can say or do for you on this.
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Didée
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Re: DGAvcDecDI crashes when playing mkv-file

Post by Didée »

admin wrote:The MT documentation warns that SetMTMode(5,0) is very slow. Here you can see it..
That's not what the documentation is talking about. Mode 5 is "slow" because it *effectively* uses only 1 Thread. The slowdown you're experiencing here has nothing to do with that.

First off, I'm wondering what you're trying to achieve here. Tweak(sat=0.0) is a zero-cost filter (or close to). Isolated from the rest, this filter runs (single-threaded!) at ~1500fps on SD-PAL video for me. Hence, your script is 99% limited by the decoding speed of the source filter, there is zero speed gain to expect from MT.
My little practice test:
1Thread-script without Tweak: 2:58 m:s
1Thread-script with Tweak: 3:00 m:s
8Thread-script with Tweak: 3:02 m:s (thats mode=5 before sourcecall, mode=2 before tweak)

However, the slowdown that you are getting shouldn't happen, of course ... expected would be "same" speed as single-threaded. It could be related to thread syncronization a/o out-of-order frame requests to the source filter. However, I really know too little about the inner workings of Avisynth and its multithreading-models to draw any definitive conclusions...

You might try the readahead/caching-trick, and see if it changes anything:

--------------------------------------------------------------
SetMTMode(5,0)
loadplugin("D:\DGAVCDecDI\DGAVCDecodeDI.dll")
DGSource("00271.dgi")
ChangeFPS(last,last,true) # forces Avisynth to do a small readahead & cache the pre-read frames. A buffer of ~20 frames, or so.
SetMTMode(2,0)
Tweak(sat=0.0)
assumefps(5000)
--------------------------------------------------------------

In any case, (it seems to me that) SetMTMode is not awfully effective with only two threads (Dualcore CPU). From my experience, good performance is achieved with 4 to 8 threads ... my poke in the blue: with only two threads, the overhead of thread synchronization is eating up a good part of the theoretical gain. On a Dualcore, you're probably better off with the [spatial] MT() instead of the [temporal] SetMTMode().

Note: I can only speak for DGDecode/mpeg2source and DGDecNV/DGSource. DGDecDI is not of interest for me - scope is too small. I use DGDecode and DGDecNV whenever they're applicable. In the remaining cases, decoding is done by ... a filter you don't particularly like, Don. ;)
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

Didée wrote:In the remaining cases, decoding is done by ... a filter you don't particularly like, Don. ;)
What filter is that and why do you think I don't like it? If you are talking about CoreAVC I am a registered user. I don't understand why this comment of yours was necessary.
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Didée
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Re: DGAvcDecDI crashes when playing mkv-file

Post by Didée »

Oops, sorry ... there was no pun intended! (And the unnamed decoder is an eff-eff-something...)

I just wanted to make clear that in case of a problem specific to DGDecDI, I'm not able to report anything.
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prokhozhijj
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Re: DGAvcDecDI crashes when playing mkv-file

Post by prokhozhijj »

Thanks a lot, Donald, for your work and testing.

1.I've noticed that on Test2 your plugin runs properly. But on Test3 always crashes.

===============
Test2
===============
------------------------------------
DGAVCDecodeDI+DiAVC+MT
------------------------------------
with SetMTMode(2,0) - 20-30 fps with 60% CPU load
with SetMTMode(5,0) - 110-140 fps with 25-30% CPU load.

------------------------------------
DSS2+ffmpeg_mt+MT
------------------------------------
Test2 with SetMTMode(2,0) - 100-110 fps with 100% CPU load
Test2 with SetMTMode(5,0) - 110-140 fps with 25-30% CPU load.

===============
Test3
===============
------------------------------------
DGAVCDecodeDI+DiAVC+MT
------------------------------------
Always crashes

------------------------------------
DSS2+ffmpeg_mt+MT
------------------------------------
110-140 fps with 25-30% CPU load


2. For two my files (they are large - about 10-11 Gb in lossless h.264 format) DGAVCIndexDI and Avisynth+DSS2() shows different frame count. Could you advice, please, is it can be checked by third-party tools? Because for now I don't know which tool is correct.

For the first file the difference between frames quantity is 112461 (Avisynth) - 112440 (DGAVCIndexDI) = 21.
For the second file 103013(Avisynth) - 102960 (DGAVCIndexDI) = 53.
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admin
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Re: DGAvcDecDI crashes when playing mkv-file

Post by admin »

I don't know anything about DSS2() and therefore will not speculate about differences in the reported frame counts.
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