Hello all, Just wondering if anyone had any thoughts on the grepability issue, which I believe is the only potential issue/breaking change with this patch.
Thanks, Kevin On Sun, Jun 11, 2017 at 9:59 PM, Kevin Mark <kmark...@gmail.com> wrote: > Hi Michael, > > Hoping to get your thoughts on the grepability issue (wrt my previous > email). If it needs to be on a single line there's no reason the new format > cannot be changed to do so (removing the \n and adding a separator, really). > However I'm a big fan of it as-is (for both scale and scale2ref) and I can't > find a case of my own where the regex I proposed would be troublesome. > > Thanks, > Kevin > > On Tue, Jun 6, 2017 at 4:17 PM Kevin Mark <kmark...@gmail.com> wrote: >> >> On Tue, Jun 6, 2017 at 11:49 AM, Michael Niedermayer >> <mich...@niedermayer.cc> wrote: >> > yes but its much harder to grep for as its not a single line anymore >> >> I agree that it's not going to be as pretty a regular expression to >> grep through, as there is 33% more data, but it should still be doable >> without too much effort. How important is it that we maintain "API" >> compatibility on verbose CLI output? >> >> ffmpeg [...] scale2ref=0:0 [...] -v verbose - 2>&1 >/dev/null | grep -oP >> 'regex' >> >> Where regex is: >> >> (in|out|ref) +w:(\d+) h:(\d+) fmt:(\w+) sar:(\d+)\/(\d+)(?: >> flags:0x[[:xdigit:]]+)? >> >> Assuming GNU grep 2.25+, you'll get: >> >> in w:320 h:240 fmt:rgb24 sar:1/1 >> ref w:640 h:360 fmt:rgb24 sar:1/1 >> out w:640 h:360 fmt:rgb24 sar:3/4 flags:0x2 >> >> It also works with BSD grep 2.5.1-FreeBSD included in macOS if you use >> the -E option instead of -P. These would be considered three separate >> matches so if you're using a good regex engine it'd be pretty easy to >> loop over each match, check the first group to determine if it's in, >> ref, or out and act accordingly on the rest of the captured data. You >> could also, if you wanted, assume that the first line is in and the >> second line is out if you only have two matches (or lines even) and if >> you have three matches/lines the first is in, second is ref, third is >> out. If you needed it to work with less sophisticated engines it >> shouldn't be too hard to dumb down the regex above. >> >> Live-ish example: https://regex101.com/r/wvHLpa/1 >> >> Is there a special property that makes single lines much easier to >> grep? Something specific to bash? I wouldn't think bash would have any >> problems looping over this by line. >> >> Thanks, >> Kevin _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
