Open mxsrm opened 2 years ago
However, for example SVT-AV1 uses /65536 (and others), which lead to wrong values.
There is a standard about values, with exact numbers, but someone decided to use another denominator... Fun! It leads to non precise values e.g. 20493/65536=0.312698 vs 0.312670 elsewhere, and I hope for the person who chose that the future will not require the value 1.0 (impossible to store in the stream with this denominator).
Thank you for the precise report, we won't o as FFmpeg with the explicit denominator but we'll use the right one for showing the right floating point value.
@mxsrm I have that now:
Mastering display color primaries : Display P3
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
But still:
Maximum Content Light Level : 2594 cd/m2
Maximum Frame-Average Light Level : 1698 cd/m2
Are there the expected values, else what are they?
@mxsrm how do you get the mastering metadata with ffprobe?
While checking the only AV1 file I have, and it is 50000 based, I don't remind where I got it and I am curious about what FFmpeg says. I bet it will show 65536 based values but I would like to be sure (in case there is somewhere a check on "bad" behavior in "old" encoders?). This is not for not implementing the 65536 based analysis as the spec is clear about it ("0.16 fixed-point").
Have you tried the file I attached above? I think the denominator is dependent on the encoder. Maybe AOM produces 50000-based and only SVT-AV1 does 65536-based, I'm not sure.
ffprobe -i test.mkv -select_streams v:0 -show_frames -read_intervals %+#1
Maximum content light and frame-average light level are correct, because there is no denominator involved:
[SIDE_DATA]
side_data_type=Content light level metadata
max_content=2594
max_average=1698
[/SIDE_DATA]
Hello,
mediainfo is parsing HDR side_data wrong. It seems to have been tested on x265 data mainly, which uses
/50000
values:However, for example SVT-AV1 uses
/65536
(and others), which lead to wrong values. Test file attached.ffprobe (exact same raw data as the example above):
But the info displayed by mediainfo is wrong:
Mastering display luminance should be
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
for examplehttps://user-images.githubusercontent.com/7951225/162791238-a185f277-8415-4f64-8279-796858b4019b.mp4.