<p>it is a problem with  gamma settings youre using and QT has its own gamma settings, dont bother. it will display only in QT that way...</p>

<p>also check for alphas, but im not so sure that mp4 can support alpha channels... only qt mov with animation codec has alpha.... as i know...</p>

CC BY-SA 3.0
2011-10-17T23:26:24.520Z
mp4 cant support alpha channels.
H_7
CC BY-SA 3.0
2011-10-19T15:13:56.307Z
It does seem a bit of a problem that videos would not display properly in Safari and on iPads, will do some more searching, would be good to work out how to create a QuickTime version that displayed properly
Tom
CC BY-SA 3.0
2011-10-19T19:44:20.410Z
First thing to consider, Mac OS X and Windows have different gamma setups for screens, so thats a part of your shift in white. Second thing to consider is, what is encoding preset like, third, send us few screenshots from both setups so we can see the difference in white more clearly.
Desmond
CC BY-SA 3.0
2011-10-17T08:18:56.087Z
2011-10-17T08:18:56.087Z
Desmond
<p>I am converting a .MOV file into .MP4, .OGV and .WEBM for web use. I have found that the background rendered by QuickTime and Safari is not white although the same MP4 has a white background when viewed with Windows Media Player.</p>

<p>The video is compressed using <a href="http://www.mirovideoconverter.com/" rel="nofollow">http://www.mirovideoconverter.com/</a> which uses ffmpeg (conversion parameters used are listed <a href="https://develop.participatoryculture.org/index.php/ConversionMatrix#Output_Formats" rel="nofollow">https://develop.participatoryculture.org/index.php/ConversionMatrix#Output_Formats</a>)</p>

<p>Can anyone tell me why this is and how I would correct the output for QuickTime?</p>

CC BY-SA 3.0
2011-09-14T20:28:46.640Z
I wonder if your video has an Alpha channel that's creating a partially or fully transparent background. Then each player and codec is displaying that transparency different.
Andrew
<video><compression><conversion><quicktime>
Background color of MP4 rendering incorrectly in QuickTime
Tom
# Background color of MP4 rendering incorrectly in QuickTime

(Asked by: username_0 on 2011-09-12)

I am converting a .MOV file into .MP4, .OGV and .WEBM for web use. I have found that the background rendered by QuickTime and Safari is not white although the same MP4 has a white background when viewed with Windows Media Player.

The video is compressed using <http://www.mirovideoconverter.com/> which uses ffmpeg (conversion parameters used are listed <https://develop.participatoryculture.org/index.php/ConversionMatrix#Output_Formats>)

Can anyone tell me why this is and how I would correct the output for QuickTime?

**Tags:** video, compression, conversion, quicktime

> **Comments:**
> **username_1**: I wonder if your video has an Alpha channel that's creating a partially or fully transparent background. Then each player and codec is displaying that transparency different.  

---

## 1 answers

### Answer by username_2 on 2011-10-17. Score: 2

it is a problem with gamma settings youre using and QT has its own gamma settings, dont bother. it will display only in QT that way...

also check for alphas, but im not so sure that mp4 can support alpha channels... only qt mov with animation codec has alpha.... as i know...

> **Comments:**
> **username_3**: mp4 cant support alpha channels.  
> **username_0**: It does seem a bit of a problem that videos would not display properly in Safari and on iPads, will do some more searching, would be good to work out how to create a QuickTime version that displayed properly  
> **username_2**: First thing to consider, Mac OS X and Windows have different gamma setups for screens, so thats a part of your shift in white. Second thing to consider is, what is encoding preset like, third, send us few screenshots from both setups so we can see the difference in white more clearly.  

---

