<p>Put keyframe distance in the encoding options to KEY EVERY FRAME.</p>

<p>When you export in the export options you have keyframe distance, which is used to calculate "intermediate key points/key frames", and the default is 25/30 frames. The player calculates pixels and frames inbetween keyframes. Sometimes it gets lost in calculation because of lost bits or bytes. Having less distance between keyframes reduces the chance of this, and results in more accurate frame rendering. </p>

CC BY-SA 3.0
2011-10-27T17:45:57.153Z
I've edited your comment into your answer (and removed our now-outdated comments), so that the answer is much clearer. In general this is a better place to put explanation, since it's easier to read and the comments aren't really "part" of the answer anyway - just associated with it. If I've made any error, please do edit the question to fix it.
Warrior Bob
CC BY-SA 3.0
2011-10-17T08:39:57.747Z
2011-10-27T17:43:32.463Z
2011-10-27T17:43:32.463Z
Desmond
<p>This has nothing to do really with Codec. Even if the stream is fully corrupt, the media player needs to portray only such things within the UI window. </p>

<p>This could be most likely a device driver or software dependency with player having issue. try alternative players. </p>

CC BY-SA 3.0
2012-03-15T20:17:08.063Z
2012-03-15T20:17:08.063Z
Dipan Mehta
<p>(Note: the video is a screencast hence the desktop icons, that's not actually the desktop of the machine having the error.)</p>

<p><img src="https://i.sstatic.net/K1IN1.png" alt="enter image description here"></p>

<p>We are using JWPlayer, and we rarely have this issue, but on it is frequently reported by customers and becoming a repeat issue. We've had them update their Flash player to the latest version. What causes this? My guess is codecs or video driver issues but I am not sure how to fix.</p>

CC BY-SA 3.0
2011-09-12T21:59:23.293Z
".mp4" doesn't tell us anything about the codec. (See [this](http://avp.stackexchange.com/questions/2293/how-to-make-sense-of-video-file-formats) question, asked just recently.)
leftaroundabout
CC BY-SA 3.0
2011-09-13T16:40:39.920Z
Does the problem go away when a keyframe pops up?  I've seen this quite a bit, always due to video corruption.  The problem should go away on the next keyframe.  If it doesn't, something else is likely wrong.
Brad
CC BY-SA 3.0
2011-09-13T20:44:27.010Z
@leftaroundabout sadly I don't know anything about the codec, but I was curious to know if it might be a codec issue
MetaGuru
CC BY-SA 3.0
2011-09-13T20:48:15.913Z
You can see what codec it is when you open it in, for instance, VLC.
leftaroundabout
<video><windows><codec>
What could be causing these strange MP4 video playback corruptions on some machines?
MetaGuru
# What could be causing these strange MP4 video playback corruptions on some machines?

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

(Note: the video is a screencast hence the desktop icons, that's not actually the desktop of the machine having the error.)

![enter image description here](https://i.sstatic.net/K1IN1.png)

We are using JWPlayer, and we rarely have this issue, but on it is frequently reported by customers and becoming a repeat issue. We've had them update their Flash player to the latest version. What causes this? My guess is codecs or video driver issues but I am not sure how to fix.

**Tags:** video, windows, codec

> **Comments:**
> **username_1**: ".mp4" doesn't tell us anything about the codec. (See [this](http://avp.stackexchange.com/questions/2293/how-to-make-sense-of-video-file-formats) question, asked just recently.)  
> **username_2**: Does the problem go away when a keyframe pops up?  I've seen this quite a bit, always due to video corruption.  The problem should go away on the next keyframe.  If it doesn't, something else is likely wrong.  
> **username_0**: @username_1 sadly I don't know anything about the codec, but I was curious to know if it might be a codec issue  
> **username_1**: You can see what codec it is when you open it in, for instance, VLC.  

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## 2 answers

### Answer by username_3 on 2011-10-17. Score: 1

Put keyframe distance in the encoding options to KEY EVERY FRAME.

When you export in the export options you have keyframe distance, which is used to calculate "intermediate key points/key frames", and the default is 25/30 frames. The player calculates pixels and frames inbetween keyframes. Sometimes it gets lost in calculation because of lost bits or bytes. Having less distance between keyframes reduces the chance of this, and results in more accurate frame rendering.

> **Comments:**
> **username_4**: I've edited your comment into your answer (and removed our now-outdated comments), so that the answer is much clearer. In general this is a better place to put explanation, since it's easier to read and the comments aren't really "part" of the answer anyway - just associated with it. If I've made any error, please do edit the question to fix it.  

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### Answer by username_5 on 2012-03-15. Score: 0

This has nothing to do really with Codec. Even if the stream is fully corrupt, the media player needs to portray only such things within the UI window.

This could be most likely a device driver or software dependency with player having issue. try alternative players.


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