Author Topic: Problems editing webm files  (Read 705 times)

HelpPlease

  • Newbie
  • *
  • Posts: 12
Problems editing webm files
« on: August 03, 2017, 10:27:26 PM »
I am trying to edit webm files.

Typically the info is something like:
Codec 4CC:      VP8
Image Size:      480 x 360
Aspect Ratio:      1:1 (1:1)
Frame Rate:      999.999 fps

When I save the output using Copy for Video and Audio Output, and Webm Muxer for Output Format, the video is corrupted (very blocky).

Can anyone please suggest different settings which would not cause much loss of quality (or result in a much bigger file)?


Jan Gruuthuse

  • Hero Member
  • *****
  • Posts: 5526
Re: Problems editing webm files
« Reply #1 on: August 04, 2017, 05:40:27 AM »
What is the source of the video? Frame Rate:      999.999 fps, 1000 frames/second?
Did you edit the video?

eumagga0x2a

  • Hero Member
  • *****
  • Posts: 1317
Re: Problems editing webm files
« Reply #2 on: August 04, 2017, 11:32:55 AM »
Please try the latest nightly. If the problem persists, please provide a sample (or at least the log file (admlog.txt on Windows)).

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #3 on: August 04, 2017, 02:12:56 PM »
What is the source of the video? Frame Rate:      999.999 fps, 1000 frames/second?
Did you edit the video?

This happened with several Youtube videos I downloaded. If I downloaded as MP4, no problem. If in WEBM format, I save them and the saved video has this blocky appearance.

Is the Frame Rate unusually high? The same thing happened with a video which had this info:
Codec 4CC:      VP8
Image Size:      640 x 480
Aspect Ratio:      1:1 (1:1)
Frame Rate:      29.970 fps

I thought I might be causing the problem somehow in my editing, so I tried opening the files and saving them without making any changes. This made no difference, they were still blocky even though they should have been exact copies (?)

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #4 on: August 04, 2017, 02:19:25 PM »
Please try the latest nightly. If the problem persists, please provide a sample (or at least the log file (admlog.txt on Windows)).

OK, thanks, I will try this as soon as I can.

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #5 on: August 05, 2017, 02:25:51 PM »
Hi. I installed avidemux_2.7.0_r170727_win32.exe and I got the same result.
I probably should have mentioned that I'm still using Windows XP on this computer.
I want to attach the log file and a couple of samples of what it looks like in VLC.
Log file is too large, I will try splitting it.
« Last Edit: August 05, 2017, 02:33:08 PM by HelpPlease »

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #6 on: August 05, 2017, 02:51:03 PM »
Part 2 of log

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #7 on: August 05, 2017, 02:51:47 PM »
Part 3

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #8 on: August 05, 2017, 02:52:38 PM »
And snapshots

eumagga0x2a

  • Hero Member
  • *****
  • Posts: 1317
Re: Problems editing webm files
« Reply #9 on: August 07, 2017, 09:34:14 AM »
This is unfortunately a known issue in getCompressedPicture and is not related to a particular muxer. Each time a decoding time stamp fails plausibility check the frame gets dropped causing severe video corruption.

mean

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 10936
Re: Problems editing webm files
« Reply #10 on: August 07, 2017, 09:49:32 AM »
This has been fixed for VP9, not for VP8 i'm afraid

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #11 on: August 07, 2017, 12:35:39 PM »

Thanks for getting back to me so quickly.

Is there any chance that the issue will be fixed in the future?

Can you suggest any workaround? The frustrating thing is that the videos play OK in Avidemux, the problem only happens when I save them.

When I download videos from Youtube using Keepvid, I tend to choose 360p Webm over 480p MP4, because I've always thought that they look slightly better. Of course the HD MP4 version is better still, but not always available.

All of the Webm videos that I have looked at, use VP8.

mean

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 10936
Re: Problems editing webm files
« Reply #12 on: August 07, 2017, 02:04:30 PM »
If it plays ok inside avidemux it is another problem

eumagga0x2a

  • Hero Member
  • *****
  • Posts: 1317
Re: Problems editing webm files
« Reply #13 on: August 07, 2017, 04:27:39 PM »
This is the problem with the test for

Code: [Select]
_nextFrameDts>(signedDts+(int64_t)(vid->timeIncrementInUs/3))
in getCompressedPicture from avidemux/common/ADM_editor/src/ADM_edVideoCopy.cpp:335. If it is true, the frame gets discarded. Often, but not always, disabling the jump to againGet (thus ignoring wrong DTS) allows Avidemux to save video and the result plays fine. Sometimes issues with rejected frames just point to an error somewhere earlier, e.g. in the demuxer.

HelpPlease

  • Newbie
  • *
  • Posts: 12
Re: Problems editing webm files
« Reply #14 on: August 07, 2017, 08:08:24 PM »

Would it help if I sent you the file I was working on when I generated the log file?