#2452: decoding yuv420p to rgb shifts luminance down
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Reporter: burek | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: unspecified | undetermined
Keywords: | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Comment (by glopes):
Sorry for that. You can download an example video from here:
https://dl.dropboxusercontent.com/u/3907539/video.avi
Running the following commandline produces a bitmap with the correct
luminance values:
{{{
ffmpeg -ss 0.5 -i video.avi -vframes 1 -t 1 -s 1280x680 -pix_fmt gray
gray.bmp
}}}
Running the following commandline produces a bitmap in which the luminance
values are shifted ~10 values darker:
{{{
ffmpeg -ss 0.5 -i video.avi -vframes 1 -t 1 -s 1280x680 -pix_fmt bgr24
rgb.bmp
}}}
Also playing this video file in VLC produces the correct luminance values.
The video was acquired from a grayscale camera and encoded as grayscale
pixel format to mpeg4 yuv420p using FFMPEG (as you can see from the
commandline output shown in the original ticket).
Hope this helps to clarify the issue.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2452#comment:2>
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