Starting to test Comskip with h.264 support

[erik]

The tuning depends on the content and not on the source.
Set
detect_method=11
to get the least agressive settings
Increase in steps to 43,47,101,111
Or any other combination.
Do not set
intelligent_brightness=1 but keep this at 0

[Phydeaux]

Thanks Eric. I'll play around more this coming weekend and maybe offer some feedback.

RLW

[webwalker]

Boy it looks like comskip is getting ready to knock it out of the park again.

Since I'm coming in on the second act, here's what I'd like to know:

I use comskip as packaged in the comskip monitor for sage and skip files read by sagemc. My wife thinks comskip is the coolest....!

We pick up all of our shows over an HDHR or capped from a PVR-150, generating mpgs. Comclean paired with mencoder looks like the best pair for actually removing the commercials from the mpgs.

Here's the $64k question: Does the sage transcoder deal with these chopped up mpgs gracefully enough to allow me to do post cutting h.264 compression on them? Comskip is fantastic....but if I squash a program to save space, I currently lose access to my comskipping in SageMC. I just want to get my file size down from the full size mpg captures to something more sustainable. (BTW this is largely for children's programming; my wife and I typically watch and then delete our programming, so comskip for h.264 or mp4/divx isn't necessary for us. But those kids programs are filling the drive FAST!)

Anyway, that's the ask. Any suggestions?

[SWKerr]

THis is not really an answer to you comeskip question but:

Well at $100 for a 1tb hard drive the simplest solution is just to add more space. I also set a limit on the number of any one show Sage will record for the kids shows. After that it just stops recording new ones. I let them know if they want new shows they have to delete something. Even the 7 year old would prefer something new if it is available.

Also: you can automatically compress those files to more than half the original size and still not loose any quality the kids would miss. This can be done by show. I think comskip would still be accurate after but I have not done it since my BeyondTV days since I have so much disk space now.

[webwalker]

Perhaps I'm not understanding the comskip issue then: My understanding is that after comskip works its magic and provides the cutpoint file, that cutpoint file is only accurate against the ORIGINAL MPG record, e.g. SageMC cannot use the cutpoint file to accurately comskip if the original mpg recording is transcoded to a different (possibly lossier, smaller) file.

Or have I completely misunderstood the problem?

M

[gplasky]

Comskip only understands mpg and h.264. the edl list is a time offset list. So it sounds like they should work. And if you're recording from a hd-pvr it is already in the most efficient format from a quality perspective and file size. (HD recordings are large by nature.)

Your other choice would be to cut the commercials out of the recordings BEFORE transcoding them.

And actually your third choice is to just buy more hard drive space. It's cheap enough and saves you from messing with the files at all.

Gerry

EDITED my post for corrections.

[Djc208]

The comskip file should work after conversion. I think the comskip file just contains the time stamps of the commercials (from xx.xx time to xx.xx time). So converting to a different format won't affect the time stamp at which the commercial exists in the video since they all play at the same speed.

However you need to make sure that your comskip monitor is set up to recognize the converted file formats. If you convert from an .mpg file to a h.264 file with a different extension then comskip monitor will delete the comskip files for that program thinking it was deleted.

In the setup web routine there is an option to set the identified file extensions to prevent comskip monitor from deleting the comskip files after the video has been converted to a different format. Try re-running the setup and add in the h.264 file extension and it should work.

[Phydeaux]

I've upgraded to build 14 of Comskip and it's now consistently crashing on every attempt to use it. I reverted to 13, which previously never failed on me, and it's still crashing.

I made two changes to the Sage Server which Comskip runs on at roughly the same time: upgraded the versions of Haali media splitter and FFDShow. Other than that, I've changed nothing. Does Comskip have some dependencies? Any ideas?

RLW

[gplasky]

I would be careful with ffdshow. I think that also uses libavcodec.dll as does Comskip.

Gerry

[webwalker]

Desoto & Gerr,

Thanks for the input. I think I just don't have Comskip looking for the file types. So I'm flog through that setup screen and see if it changes anything.

I would prefer to run comclean on the MPG file to chop the commercials out of it and then re-compress as h.264. This reduces the file size even further.

And I know that 'disk is cheap.' But since I've got almost a grand in to all of the thrashing required to have achieved this modest level of success, I'm not in a position to 'buy more disk' yet. I'm planning on getting to at least June before I have to broach the subject of 'upgrade.'

[erik]

Originally Posted by Phydeaux

I've upgraded to build 14 of Comskip and it's now consistently crashing on every attempt to use it. I reverted to 13, which previously never failed on me, and it's still crashing.

I made two changes to the Sage Server which Comskip runs on at roughly the same time: upgraded the versions of Haali media splitter and FFDShow. Other than that, I've changed nothing. Does Comskip have some dependencies? Any ideas?

RLW

This may be the long hoped for clue!
Could you rename/remove the libavcodec.dll in the comskip directory and see if Comskip still "runs", that is it starts to process the recording but then it crashes?
Or even better, find the libavcodec.dll used with ffdshow, rename that to another file extension and see if Comskip now magically works?

[Phydeaux]

Thanks for the heads-up Gerry.

FFDShow did indeed install a never version of libavcodec.dll . So I uninstalled FFDShow and did a search for libavcodec.dll on system to insure that the only one was in the same directory as Comskip and that it is the one that comes with Comskip. Comskip still fails every time with every recording I feed it. It runs for several minutes, seemingly progressing through the media and then just dies. Windows reports an unexpected program termination. The log file gives me no particular clue, although I really don't know what I would be looking for.

The ONLY other thing I changed at about the time this started happening was that I changed my satellite STB to output 480p instead of 1080i which it was previously set at. So the TS files I'm feeding Comskip are these 480P ones.

Any ideas? Erik, do you want to see a log file or anything?

RLW

[gplasky]

Did you reboot the box after removing ffdshow? If not try that. ALso make sure you have in folder properties that "see hidden files" are enabled. And search agan making sure it also searches system folers.

Gerry

[Phydeaux]

Yes, I did reboot the machine afterwards. And my search included all hidden files and directories. The only ones I found were inside zip files in a directory that is not in the PATH.

RLW

[erik]

Originally Posted by Phydeaux

The ONLY other thing I changed at about the time this started happening was that I changed my satellite STB to output 480p instead of 1080i which it was previously set at. So the TS files I'm feeding Comskip are these 480P ones.

RLW

Did you test with an old recording of 1080i?

[Phydeaux]

I knew someone was going to ask exactly that question. No, I no longer have any older 1080i material that previously worked. I've just recently started playing around with Comskip and was not particularly happy with the results at version 11 &12. Version 13 got much closer to what I would consider acceptable with out of the box settings. But once I've watched the recorded episode I generally just delete it.

I'll do a test tonight and record at a couple different resolutions, then run comskip on them and report back the results. I'll also bring along the log files to work in case you want to see them. I just don't understand why comskip would work fine one day and not at all the next, when nothing material has changed about the environment. The possible dll file version made sense, but proved to be not a factor. I wonder if I need to reboot the HD PVR? Although, the files I'm getting out if it are playing fine...

RLW

[erik]

Unfortunately the log file does not contain the h.264 decoder messages
You can send them to a file by starting comskip as
comskip.exe filetoprocess.ts 2>error.log

I like to see this error.log

[Phydeaux]

Good to know Erik, I'll do exactly that in order to generate more helpful log files.

RLW

[Phydeaux]

I have to confess I have no idea now what's going on as I'm getting inconsistent results with Comskip. Last evening I recorded two more 30 minute shows - one in 480p and one in 1080i (just toggled the component video output on the STB). I ran them through Comskip from the command prompt as directed by Erik to collect more informative log files. They ran fine without Comskip crashing, whereas for the previous several days everything I threw at Comskip caused it to crash after several minutes of processing. Absolutely nothing has changed since the last time I tried a recording. So, I re-tried these same new recordings by just dragging them onto the Comskip shortcut on my desktop. Again, now it works fine. Well, by fine I mean it didn't crash - it's only about 60% accurate finding commercials.

I do note that when I drop files onto the comskip shortcut there are a number of error messages that come up which do not appear in the log, but after these error messages it seems to carry on processing fine.

Example:
[h264 @ 036B3A90]error while decoding MB 20 0, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 70 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 102 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 37 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 43 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 34 2, bytestream (td)
[h264 @ 036B3A90]mmco: unref short failure
[h264 @ 036B3A90]error while decoding MB 45 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 51 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 42 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 27 2, bytestream (td)
[h264 @ 036B3A90]mmco: unref short failure
[h264 @ 036B3A90]error while decoding MB 29 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 39 2, bytestream (td)
[h264 @ 036B3A90]error while decoding MB 33 2, bytestream (td)
[h264 @ 036B3A90]mmco: unref short failure

Erik, I do have the log files for the two recordings that I did last night if you're interested in seeing them. If nothing else maybe you can give me some pointers about why comskip seems so hit and miss with respect to detecting commercials. Is there someplace for me to upload these log files?

RLW

[erik]

No need to upload,

When you see a lot of these messages you need to set
volume_slip=150