NEW226776
Colorimetry-related warnings with H264 encoded with iOS Safari
https://bugs.webkit.org/show_bug.cgi?id=226776
Summary Colorimetry-related warnings with H264 encoded with iOS Safari
Nazar Mokrynskyi
Reported 2021-06-08 13:01:46 PDT
When encoding H264 on iOS, its contents doesn't seem to contain colorimetry information when decoded by GStreamer, resulting in following warnings: > 2:59:30.649107764 1 0x7f0298049400 WARN video-info video-info.c:204:validate_colorimetry: Need to specify a color matrix when using YUV format (I420) > 2:59:30.649125302 1 0x7f0298049400 WARN video-info video-info.c:520:gst_video_info_from_caps: invalid colorimetry, using default Those warnings are not present when VP8 is used, not present with desktop Safari and H264 (which makes me think it is related to hardware-accelerated encoder) and not present with Firefox/Chromium. Those are annoying warnings and would be nice to fix in iOS version of Safari.
Attachments
youenn fablet
Comment 1 2021-06-14 01:55:42 PDT
Thanks Nazar, can you detail whether this is with high profile or baseline? Can you detail the impact of the issue?
Nazar Mokrynskyi
Comment 2 2021-06-14 02:03:53 PDT
This is baseline. The impact is primarily A HUGE amount of warnings in logs, visually there doesn't seem to be anything bad, I guess GStreamer's default works fine there.
youenn fablet
Comment 3 2021-06-14 08:26:13 PDT
It would help to understand what the spec says here. That will tell us whether encoder should be fixed, or decoder, or application using decoder output.
Nazar Mokrynskyi
Comment 4 2021-06-14 08:31:10 PDT
Decoding is done by libav integration in GStreamer, so application using it doesn't do anything special. And since it works fine with every other browser I tried so far except mobile Safari, I believe it is mobile Safari that needs to be tweaked here. But I'm not an expert in the field to suggest something more specific.
Radar WebKit Bug Importer
Comment 5 2021-06-15 13:02:16 PDT
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