Topic: Still wrong colors in Avidemux 2.5

I know this was reported already. But it still happens in the "new" Avidemux 2.5 branch sad

Correct colors in MPlayer, using OpenGL renderer:
http://img50.imageshack.us/img50/9594/admcolors3.png

Strange colors in Avidemux, still image:
http://img11.imageshack.us/img11/1808/admcolors1.png

Better colors in Avidemux while playing, but wrong levels (I think):
http://img407.imageshack.us/img407/6297/admcolors2.png

Any opinions on this? I think "wrong" colors in a video editor are a serious problem...

Last edited by LoRd_MuldeR (2010-08-29 14:10:49)

Re: Still wrong colors in Avidemux 2.5

I found a *good* testcase where this happens.

http://www.youtube.com/get_video?fmt=18 … tiKfZnhe4=
http://www.youtube.com/get_video?fmt=18 … Fbzkr6wXc=
http://www.youtube.com/get_video?fmt=18 … 40uVTWzHU=
http://www.youtube.com/get_video?fmt=18 … h2PcJkrH0=

- Download the 4 above files. Open the first and append the second.
- Use any mode (secure or insecure); Use *direct* copy; Choose MP4 or MKV as container.
- Result after encoding: First part will have perfect colors, the later part(s) totally wrong levels/lightness.

You may append all files. Look at the last 5 seconds. Big difference. (applies to Avidemux 2.4.3 and IMHO newer versions)

Re: Still wrong colors in Avidemux 2.5

v2.5 has problems importing .bmp or .png (which is another topic), so these were done with 2.4.4 QT4 (which has problems importing .bmp, but seems stable with .png)

Original RGB Belle Nuit Testchart .png format
http://i42.tinypic.com/20b0ihc.png

RGB .bmp output from avidemux (converted to .png for display purposes)
http://i44.tinypic.com/msf388.png

I tried switching using different combos of colormatrix() (i.e. rec601, rec709, SMPTE 240M, FCC) in avisynth on the avidemux output file , none matched the original

When using YV12 video input (ie. made a huffyuv yv12 (converted thru avisynth) video of the testchart), direct stream copy works ok, but the screenshot still has wrong colors.

Converting to xvid or x264 => actual video OK colors/levels , but the display inside avidemux wrong colors & taking screenshots wrong colors. So the display and screenshots correlate with avidemux, but not necessarily with the output video content

Last edited by poisondeathray (2009-03-24 18:55:59)

Re: Still wrong colors in Avidemux 2.5

Yes, Avidemux' internal display definitely shows wrong colors, although the actual output is always fine.

I wonder if OpenGL could be used for the preview in Avidemux, like it's already implemented in VirtualDub...

Re: Still wrong colors in Avidemux 2.5

No, the testcase I found makes the wrong lightness to be *written* to the file! yikes
While the preview seems to be acceptable, the resulting file is terrible, beginning with the first appended part!
Avidemux 2.5 *is* affected.

Instructions:
Be fast with downloading the files (or upload them somewhere else, Youtube changes download links very fast)

http://www.youtube.com/get_video?fmt=18 … m-0XXn9ZE=
http://www.youtube.com/get_video?fmt=18 … iYjmMPSsk=
http://www.youtube.com/get_video?fmt=18 … mM4pIF0Sw=
http://www.youtube.com/get_video?fmt=18 … RDYIhM2Io=
If links don't work: Search Youtube with: megara german. Parts 1.0-1.3. You must know how to download the .mp4 files!

- Download the 4 above files. Open the first and append the second.
- Use any mode (secure or insecure); Use *direct* copy; Choose MP4 or MKV as container.
- Result after encoding: First part will have perfect colors, the later part(s) totally wrong levels/lightness.

You may append all files. Look at the last 5 seconds. Big difference. (applies to Avidemux 2.4.x and 2.5)

Left picture: Good Original!
Right picture: Mess after encoding!

AvidemuxExampleEncoding

Last edited by demuxguy (2009-03-25 01:49:51)

Re: Still wrong colors in Avidemux 2.5

@demuxguy: When you are running Avidemux in "COPY" mode, it will copy the frames unchanged from the source file to the output file. Therefore it's technically impossible that the colors are changed. So what you are experiencing most likely is a playback problem. More specifically this may be yet another "PC Levels -vs- TV Levles" problem...

Please read on for further information:
http://forum.doom9.org/showthread.php?t=143689

  • mean
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Re: Still wrong colors in Avidemux 2.5

It could be the file contains some additional color conversion informations that are skipped/deleted when copying

Re: Still wrong colors in Avidemux 2.5

Yes, and it happens only in "direct copy" mode and only with *appended* parts.
The first quarter of the resulting file plays ok.
-----------------------------------------------------------------------------------------------------

I have updated the way to download the files:
Go to "http://keepvid.com/" enter a URL and choose the mp4 download link. Give a each file a new name.

http://www.youtube.com/watch?v=ZgIdNyFYedw
http://www.youtube.com/watch?v=EAM34uQYHb8
http://www.youtube.com/watch?v=3gNBAfUY-c4
http://www.youtube.com/watch?v=RALF-JkQpc8

Then simply *merge* the videos into a new file. (Open first part, append the latter, MP4/MKV Container, save as new file)

@LoRd_MuldeR: It happens with all players I have: MPC (ffdshow) chosing different renderers, vlc, mplayer

Re: Still wrong colors in Avidemux 2.5

demuxguy wrote:

@LoRd_MuldeR: It happens with all players I have: MPC (ffdshow) chosing different renderers, vlc, mplayer

Still Avidemux doesn't modify the frames in "Copy" mode. So the only reason I can think of is what Mean said:
There must be some color(space) information in the stream(-header) that gets discarded somehow...

Re: Still wrong colors in Avidemux 2.5

Yes, I agree. This was also the reason why I was posting: Truly unexpected result for the chosen mode.
Now that the main developer is aware of the problem, I'm leaving for a while. Good luck! smile

Re: Still wrong colors in Avidemux 2.5

Unfortunately the merge bug is still there in Avidemux 2.5.0. See relevant comments 7 and 8.

IssueImage

Re: Still wrong colors in Avidemux 2.5

I just spent a couple of hours trying to work this out.  I thought I was seeing things! :-)  Thanks for confirming the bug.

Looking forward to seeing this fixed in future versions, switched over from good old VirtualDub so still learning...

Re: Still wrong colors in Avidemux 2.5

Could it be that it has something to do with the graphics card settings which are messing around in the video output?

Re: Still wrong colors in Avidemux 2.5

Could it be that it has something to do with the graphics card settings which are messing around in the video output?

AFAIK VLC doesn't use Overlay for video playback so it shouldn't be the issue.

Re: Still wrong colors in Avidemux 2.5

I'm pretty sure the problem of "wrong" colors in Avidemux' internal preview are due to the code used for YUV -> RGB conversion. I have no idea whether Avidemux does do that itself or lets the Toolkit (Qt/GTK+) do the conversion.

Anyway, is there any chance the "high quality" RGB conversion code from ffdshow trayouts can be ported to Avidemux ???

Last edited by LoRd_MuldeR (2009-10-22 13:36:41)