[Libav-user] sws_scale - "Warning: data is not aligned!" when using opencv::Mat

Carl Eugen Hoyos ceffmpeg at gmail.com
Fri Dec 28 01:12:44 EET 2018

2018-12-23 11:19 GMT+01:00, Wodzu <brucedickinson at wp.pl>:
>> Digital video by definition has a range, for "8bit h264 video"
>> (and anything coming from dvb and dvd) it is 16..235 while it is 0..255
>> for jpeg.
>> gray can be both, you have to know before you can encode it into h264. If
>> your input is full scale (0-255) but you need an output video that can be
>> shown anywhere, the conversion is unavoidable. (I cannot know what your
>> input is.)
> Thank you, I did not know that. So, my input is 8 bit bitmap

> which I guess has range 0..255.

(Guessing is bad here because it does visually effect your output.)

In this case using the scale filter / libswscale as you have originally
done is correct, I just wanted to make sure you are not doing an
unneeded conversion.

Carl Eugen

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