nokhwa
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yuv422 confusions?
this is about 0.10
branch as senpai
is not buildable for me.
-
nokhwa-bindings-macos
seems to map both ofkCMVideoCodecType_422YpCbCr8
andkCMPixelFormat_422YpCbCr8_yuvs
toFrameFormat::YUYV
. according to apple docs,kCMVideoCodecType_422YpCbCr8
is "ordered Cb Y'0 Cr Y'1" andkCMPixelFormat_422YpCbCr8_yuvs
is "ordered Y'0 Cb Y'1 Cr." on the other hand,buf_yuyv422_to_rgb
seems assuming the latter ordering. -
on my environment (MacBook Pro (15-inch, 2018)) the camera on the top of the display seems to report
kCMPixelFormat_422YpCbCr8_yuvs
. (confirmed by adding debug code inraw_fcc_to_frameformat
) however, for some reasons, using thethreaded-capture
example, the buffers given to the callback actually seem to contain bytes in "Cb Y'0 Cr Y'1" order. (thus decoded wrong.)
cf. https://developer.apple.com/documentation/coremedia/1564239-video_codec_constants/kcmvideocodectype_422ypcbcr8 https://developer.apple.com/documentation/coremedia/1564244-video_pixel_format_constants/kcmpixelformat_422ypcbcr8_yuvs