On 05/11/17 00:46, Carl Eugen Hoyos wrote: > Hi! > > Attached patch fixes a warning on a current 64bit Linux system (that I > do not see on my ancient system where the ioctl cmd has type int). > Is there a better way to deal with it?
> Fixes a warning on recent Linux: > libavcodec/v4l2_context.c: In function 'ff_v4l2_context_set_status': > libavcodec/v4l2_context.c:496:26: warning: comparison is always false due to > limited range of data type Huh. I didn't realise that the standard Linux ioctl numbering actually acts differently on different achitectures (you don't hit this on ARM or x86-64 with a write-only ioctl, as VIDIOC_STREAMON is). The patch is probably correct, though I think I would prefer the type to be uint32_t as the ioctl numbering in Linux really is 32-bit regardless of what some external prototypes (i.e. glibc) might say. (Inside the kernel it's unsigned int, but uint32_t would be more explicit.) Thanks, - Mark _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel