Author Topic: Tiny index file  (Read 607 times)

DerAndereMicha

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Tiny index file
« on: October 22, 2019, 01:56:40 PM »
Hello,

when opening a video longer than 1 hour, only the first seconds are displayed and the resulting index file is tiny (see attachment).

Best regards
Michael

PS: The problem also occurs with the last nightly build.

eumagga0x2a

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Re: Tiny index file
« Reply #1 on: October 22, 2019, 03:11:27 PM »
We handle DTS going back situation only when we get help from the PCI in VOBU, present in streams prepared for writing to a video DVD or copied from a video DVD. To make the situation even worse, this happens here right after the first GOP, so indexing stops after 32 pictures.

Unsure what strategy might help here without breaking other valid scenarios. Any work on this topic would require your video as sample for testing (maybe the first ~100 MB would suffice) and a different sample from a DVD containing DTS resets (and spare time, of course).

DerAndereMicha

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Re: Tiny index file
« Reply #2 on: October 22, 2019, 04:38:44 PM »
This is a VLC recording of a DVB-C which is over 2 GB in size. If I could cut 100 MB, I wouldn't have a problem with the file ;-)

eumagga0x2a

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Re: Tiny index file
« Reply #3 on: October 22, 2019, 05:18:22 PM »
If I could cut 100 MB, I wouldn't have a problem with the file ;-)

You can. Even if you might need to boot Linux for that.

Code: [Select]
dd if=/path/to/input of=/path/to/output bs=1M skip=10
copies the file starting with offset of 10 MiB to output.

DerAndereMicha

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Re: Tiny index file
« Reply #4 on: November 04, 2019, 04:18:18 PM »
I don't have Linux, but the problem has reappeared and this time the file is smaller. I will send you the link as PM.



Best regards
Michael

eumagga0x2a

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Re: Tiny index file
« Reply #5 on: November 04, 2019, 10:20:58 PM »
Thank you.

Code: [Select]
[handleScrReset] 21:54:43-050  DTS are going back, maybe several video appended ?
 [handleScrReset] 21:54:43-050  Trying to correct with VOBU offset :00:00:00,000
 [handleScrReset] 21:54:43-050  last Valid Dts 01:52:42,274
 [handleScrReset] 21:54:43-050  current    Dts 01:52:42,259

 [writeScrReset] 21:54:43-050  No SCR reset detected

This small irregularity confuses Avidemux. Unfortunately, due to the video being MPEG-PS instead of MPEG-TS, simply cutting off the beginning doesn't work (you really should avoid using MPEG-PS if you can, this format is good only at the final editing stage before writing to DVD). The easiest workaround for now is to remux the video in stream copy mode with ffmpeg to MPEG-TS:

Code: [Select]
ffmpeg -i record.mpg -map 0:2 -map 0:0 -map 0:1 -c copy record-remuxed-by-ffmpeg.ts
There is still a minor hiccup at the start of the video due to broken timestamps in the original stream, but Avidemux is now able to index the entire record-remuxed-by-ffmpeg.ts file.

DerAndereMicha

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Re: Tiny index file
« Reply #6 on: November 10, 2019, 01:30:30 PM »
Unfortunately, I don't know anything about this topic at all and only use the software - like yours.  Therefore, the tipp to use MPEG-PS instead of MPEG-TS is meant dearly, but for me not so easily realizable. I use VLC to record the video stream of my cable router (AVM Fritz-Box). And in the settings of VLC I didn't find anything like that.

In case of an emergency, I will use your tip to bypass the problem with ffmpeg. But of course it would be better to have a solution that doesn't cause any problems in the first place.

Best regards
Michael

eumagga0x2a

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Re: Tiny index file
« Reply #7 on: November 10, 2019, 04:16:01 PM »
Unfortunately, I don't know anything about this topic at all and only use the software - like yours.  Therefore, the tipp to use MPEG-PS instead of MPEG-TS

The other way round -- the recomendation was to use MPEG Transport Stream instead of MPEG Program Stream.

Quote
is meant dearly, but for me not so easily realizable. I use VLC to record the video stream of my cable router (AVM Fritz-Box). And in the settings of VLC I didn't find anything like that.

Maybe it just dumps network packets to a file. The question is what or who generates the stream then. If the origin of the stream is some IPTV provider and not local (not you), we are probably out of luck, i.e. have to deal with all the defects as they happen.