[Ffmpeg-devel-irc] ffmpeg.log.20161119

[burek]

[02:16:30 CET] <yunhuali> hi, I can draw frame number with drawtext filter with text=%{n}, is there any way to draw fps?
[02:16:44 CET] <yunhuali> I want to get Frame per second.
[02:17:50 CET] <yunhuali> I want draw text like every  10 minutes, display 30second, then disappear, then show up again, 10 minutes later,
[02:29:04 CET] <llamapixel> yunhuali: One idea would be to chop up the video and apply to the segments then put it all back together.
[02:29:34 CET] <llamapixel> Idea 2 would be to make a black video with just the fps at the correct timeline locations and overlaying with additive.
[02:30:07 CET] <yunhuali> llamapixel, Thanks, I wish have better solution.
[02:30:31 CET] <llamapixel> What exactly do you want to do? that might encourage other ideas.
[02:30:35 CET] <furq> yunhuali: https://ffmpeg.org/ffmpeg-filters.html#Timeline-editing
[02:31:02 CET] <furq> i assume this is a vfr video and you can't just get it with ffprobe beforehand
[02:31:07 CET] <furq> s/it/the fps/
[02:31:49 CET] <llamapixel> oh nice enable between feature
[02:32:38 CET] <yunhuali> thank you furq, I'm actually  reading that, and was trying to do it. My idea is use drawtext=enable='between(t,10,60)')
[02:33:32 CET] <furq> http://ffmpeg.org/ffmpeg-utils.html#Expression-Evaluation
[02:33:35 CET] <furq> you probably want to read that as well
[02:33:38 CET] <yunhuali> Can I change it to between(mod(t, 600), t, t+30)'
[02:34:13 CET] <furq> you probably want between(mod(t, 600), 0, 30)
[02:35:05 CET] <llamapixel> clever
[02:38:28 CET] <yunhuali> Thanks, Furq, I just tested with ffplay, it works
[02:38:42 CET] <yunhuali> (mod(t, 60), 0, 10)
[02:38:55 CET] <yunhuali> I changed it to smaller number, so I can verify it
[02:41:02 CET] <yunhuali> Thanks!! have a nice weekend!
[06:26:33 CET] <mantas322> Hi guys
[06:26:35 CET] <mantas322> anyone here?
[12:51:54 CET] <somaReverse> hello
[12:51:58 CET] <somaReverse> I'm new to ffmpeg
[12:52:14 CET] <somaReverse> I'm very confused by these options
[12:52:23 CET] <somaReverse> https://ptpb.pw/iC51
[12:52:47 CET] <somaReverse> what do they mean? How can I make it require less cpu?
[12:55:32 CET] <DHE> https://www.ffmpeg.org/ffmpeg-all.html    while it's a lot to digest, when you need to search for what options mean this is the definitive guide
[12:59:29 CET] <somaReverse> ok, is there a pre defined option set that is suit for low cost screencast?
[13:00:28 CET] <DHE> you're using vp8, so find the libvpx section of the documentation and see what options it offers
[13:02:13 CET] <DHE> I see options named "-quality" and "-speed" that look promising
[13:08:07 CET] <somaReverse> yeah, I'm trying. thanks
[13:38:16 CET] <relaxed> somaReverse: also, https://trac.ffmpeg.org/wiki
[14:38:57 CET] <hoodedfigure> Hi, i am trying to get started with ffmpeg but it seems that the code examples at https://ffmpeg.org/doxygen/trunk/examples.html are outdated. Is that possible?
[14:43:34 CET] <JEEB> those should still build.
[14:43:52 CET] <JEEB> if they don't in the latest HEAD that's a problem
[14:44:07 CET] <JEEB> (the examples are under docs/examples or so in the git repo)
[14:44:19 CET] <hoodedfigure> I can't find function open_codec_context() anywhere in the rest of the code, actually.
[14:44:42 CET] <hoodedfigure> (in v3.2)
[14:45:49 CET] <BtbN> that's a function defines by that specific example itself
[14:46:10 CET] <JEEB> yea
[14:46:45 CET] <hoodedfigure> oh, sometimes I fee stupid
[14:46:49 CET] <hoodedfigure> thanks
[15:06:03 CET] <hoodedfigure> I basically want to be able to decode single specific frames throughout the input video. Can you give me a hint how to do that?
[15:28:26 CET] <hoodedfigure> I'm getting the following two errors: /usr/bin/ld: video.o: undefined reference to symbol 'av_image_alloc@@LIBAVUTIL_55'       /usr/lib/libavutil.so.55: error adding symbols: DSO missing from command line
[15:28:35 CET] <hoodedfigure> Is my library compiled the wrong way?
[16:51:25 CET] <DHE> hoodedfigure: compiling and linking against mismatched versions of the headers and libraries. check if you have ffmpeg installed properly
[17:51:10 CET] <Alina-malina> Hello all, how  can i add a file limit i have this <<ffmpeg -i "input" out.mp3>>  but the file is getting too big, i need to split it to chunks
[17:53:43 CET] <SchrodingersScat> does -segment_time 300 -f segment help?
[17:54:58 CET] <furq> -segment_time 300 -f segment out%03d.mp3
[17:55:48 CET] <Alina-malina> oh cool let me try this please
[18:00:53 CET] <Alina-malina> furq, oh this is so cool thanks!!!
[18:11:30 CET] <SchrodingersScat> i was there too ;(
[18:16:55 CET] <kerio> how's "too big" a thing
[18:27:01 CET] <yalopov> hello!
[18:27:22 CET] <durandal_1707> hello
[18:28:40 CET] <yalopov> i want to learn about theory behind video codecs and containers, does anyone knows if there's a book about it?
[18:32:43 CET] <furq> yalopov: http://www.dspguide.com/
[18:37:01 CET] <yalopov> impressive, that's what i was looking for
[18:37:03 CET] <yalopov> thanks
[18:43:30 CET] <jj15> So following from what I was trying to do the other day Ive done it :) Ive created interactive live streams where users get shoutouts for shating the live stream. Check it out (ffmpeg and PHP script to pull date from FB) https://www.facebook.com/ZestyBingo/videos/1343693932321218/
[18:43:44 CET] <jj15> s/shating/sharing
[18:45:53 CET] <DHE> I liked shating better
[18:54:32 CET] <jj15> ha ha
[19:00:24 CET] <yalopov> it's pretty cool!
[19:00:38 CET] <yalopov> i bit lagged i think
[19:30:04 CET] <jj15> I think the lag is my connection. Do you mean with the sound?
[19:30:11 CET] <jj15> Or the updating?
[19:31:07 CET] <jj15> With the updating my script queries Facebook every 5 seconds otherwise I get errors from their API so the image is updated every 5 seconds. I want to now try overlay a movie of snow falling.
[19:36:50 CET] <yalopov> updating
[19:36:52 CET] <yalopov> oh, i see.
[20:13:27 CET] <wouter> does it make sense to try a combination of -i "concat:foo.ts|bar.ts|baz.ts" and "-c:v copy" in the same command line, or is that totally not going to work
[20:13:39 CET] <wouter> (assuming the three .ts files have the same settings etc)
[20:44:43 CET] <DHE> wouter: if they literally are identical in codec and codec settings, then it should be safe
[00:00:00 CET] --- Sun Nov 20 2016