<p>No, it is not possible.  Mpeg-4 compression is based around storing information about patterns found within the video.  It doesn't deal with particular pixels.  Blacking out certain pixels alters the pattern and thus alters the way the video would compressed, potentially significantly.</p>

CC BY-SA 3.0
2013-06-06T13:58:38.663Z
Aha, so pixel precision is not possible. Any way to do this on a block basis maybe? On the I-Frames e.g. ? :(
Menelaos
CC BY-SA 3.0
2013-06-06T14:03:29.233Z
@meewoK - there might be a way to do it while only re-encoding the block, but I honestly don't know enough about the format.  Either way, it would likely require a special implementation of an encoder to do it as you would have to encode your change at a minimum.  I doubt you will find any existing solutions to do it.
AJ Henderson
CC BY-SA 3.0
2013-06-06T13:56:41.450Z
2013-06-06T13:56:41.450Z
AJ Henderson
<p>Basically is it possible to set the value of specific areas of pixels to black without re-encoding an MP4 video completely in an editor or application (Premiere, Ffmpeg, etc).</p>

<p>I'm wondering if such a capability exist to work directly on the compressed data as opposed to having to decode and re-encode.</p>

<video><editing>
Blacking out specific pixels in MP4 without re-encoding
Menelaos
# Blacking out specific pixels in MP4 without re-encoding

(Asked by: username_0 on 2013-06-06)

Basically is it possible to set the value of specific areas of pixels to black without re-encoding an MP4 video completely in an editor or application (Premiere, Ffmpeg, etc).

I'm wondering if such a capability exist to work directly on the compressed data as opposed to having to decode and re-encode.

**Tags:** video, editing


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## 1 answers

### Answer by username_1 on 2013-06-06. Score: 1 | Accepted answer

No, it is not possible. Mpeg-4 compression is based around storing information about patterns found within the video. It doesn't deal with particular pixels. Blacking out certain pixels alters the pattern and thus alters the way the video would compressed, potentially significantly.

> **Comments:**
> **username_0**: Aha, so pixel precision is not possible. Any way to do this on a block basis maybe? On the I-Frames e.g. ? :(  
> **username_1**: @meewoK - there might be a way to do it while only re-encoding the block, but I honestly don't know enough about the format.  Either way, it would likely require a special implementation of an encoder to do it as you would have to encode your change at a minimum.  I doubt you will find any existing solutions to do it.  

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