Hello all,
I'm writing a webcam app to display video from a video4linux device. I'm
having trouble with the function to convert the video from yuv420p
format to rgb. Its a C function that I wrapped for use in python. Here's
whats happening:
WIDTH=320
HEIGHT=240
yuvframe = mmap.read(WIDTH *HEIGHT*3)
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, yuvframe)
At this point it gives a typeerror: argument 3 must be string without
null bytes, not str.
I did some testing to see whats going on. This call also generates the
typeerror:
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, "\0\0\0\0")
but if I send it a raw string it doesn't complain:
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, r"\0\0\0\0")
I'm assuming this is happening because C interprets NULL as the end of
the string. Is there a way to get a raw string directly from the
mmap.read() call or do I have to do a conversion after the read? If I
have to convert it, what would be the fastest way to do it? I need to
get at least 5-10fps. Any help much appreciated.
Thanks,
Dan
I'm writing a webcam app to display video from a video4linux device. I'm
having trouble with the function to convert the video from yuv420p
format to rgb. Its a C function that I wrapped for use in python. Here's
whats happening:
WIDTH=320
HEIGHT=240
yuvframe = mmap.read(WIDTH *HEIGHT*3)
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, yuvframe)
At this point it gives a typeerror: argument 3 must be string without
null bytes, not str.
I did some testing to see whats going on. This call also generates the
typeerror:
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, "\0\0\0\0")
but if I send it a raw string it doesn't complain:
rgbframe = yuv.yuv2rgb(WID TH, HEIGHT, r"\0\0\0\0")
I'm assuming this is happening because C interprets NULL as the end of
the string. Is there a way to get a raw string directly from the
mmap.read() call or do I have to do a conversion after the read? If I
have to convert it, what would be the fastest way to do it? I need to
get at least 5-10fps. Any help much appreciated.
Thanks,
Dan