[Ffmpeg-devel-irc] ffmpeg.log.20190727

[burek]

[00:22:58 CEST] <nine_milli> blb
[00:25:28 CEST] <another> you got to be kidding me
[00:47:01 CEST] Action: DHE <img src="killicon_backstab.png"> nine_milli 
[04:01:56 CEST] <Henry151> man that's kinda hilarious, I remember seeing him saying blb the other day and asking "what's blb mean?" .. i didn't notice that he was just doing it all the time
[04:03:20 CEST] <furq> http://vpaste.net/OdWiN
[04:03:21 CEST] <furq> thrilling stuff
[04:07:39 CEST] <Henry151> the last three lines are the funniest
[07:36:14 CEST] <sopparus> hello, can ffmpeg extract epg info from a stream?
[07:49:57 CEST] <nine_milli> blb
[12:34:45 CEST] <roxlu> hi, when I create a test video with ffmpeg using the nv12 pixelformat and then use ffplay to playback it logs a different format. Or am I looking at the wrong output? I've pasted the outputs here https://gist.github.com/roxlu/ac7d50eb89fcdf8f7730860c2ff6b31d
[12:36:58 CEST] <durandal_1707> ffplay cant use nv12 as output format?
[12:37:25 CEST] <durandal_1707> how you store nv12 format?
[12:37:59 CEST] <roxlu> I used ffmpeg to create a .h264 file
[12:38:13 CEST] <roxlu> with the `-pix_fmt nv12` option
[12:38:29 CEST] <roxlu> but yeah I see, so ffplay converts nv12 to yuv420p before rendering?
[12:39:41 CEST] <furq> i'm pretty sure x264 always stores 4:2:0 as nv12 internally anyway
[12:40:26 CEST] <roxlu> yeah makes sense indeed furq. What I was confused about was why ffplay shows yuv420p, but I think the answer from durandal_1707 explains it
[12:40:33 CEST] <furq> well ffprobe will also show yuv420p
[12:40:44 CEST] <furq> i assume that's what the decoder defaults to
[12:41:22 CEST] <roxlu> hmm ok, I would expect them both to log the format that is actually used
[12:41:36 CEST] <roxlu> not the format they convert into.. but it's good to know
[12:42:16 CEST] <furq> it's the same data either way, just shuffled a bit
[12:42:38 CEST] <roxlu> thanks yeah, but yuv420p is 3 planes no?
[12:43:08 CEST] <furq> yeah
[15:42:00 CEST] <mia> Hello there channel
[15:42:23 CEST] <mia> Quick question: is there any natively supported way to resize videos in ffmpeg? I need to change ratio with existing resolution
[15:42:42 CEST] <mia> So I need options like "scale" "zoom" "fit width" etc -- maybe there is already a source about all this
[15:43:17 CEST] <mia> Since ffmpeg is very old and detailed, I was unable to pinpoint what I fully needed so if anyone can direct me to agood starting point to learn that'd also be enough
[15:45:53 CEST] <strongcoffee> mia, -vf scale=<value>:-1
[15:46:15 CEST] <strongcoffee> where <value> is the width of the target resize you want
[15:47:18 CEST] <mia> strongcoffee, oh, does that letterbox the video?
[15:47:30 CEST] <mia> I have square videos that I'm auto posting to instagram
[15:47:37 CEST] <mia>  and instagram crops sides
[15:47:48 CEST] <strongcoffee> no it just resizes the video as-is, preserving the aspect ratio
[15:47:51 CEST] <mia> so I want to have them in 9:16 vertical aspect ratio and letterbox them
[15:47:52 CEST] <strongcoffee> see this wiki page, https://trac.ffmpeg.org/wiki/Scaling
[15:48:56 CEST] <mia> I see - strongcoffee  - thanks for the direction
[15:49:05 CEST] <mia> I just went through the page --- I think I need a letterboxing option
[15:52:19 CEST] <strongcoffee> seems you'd want to look at the pad filter option in conjunction, https://ffmpeg.org/ffmpeg-filters.html#pad-1
[22:48:15 CEST] <nine_milli> blb
[23:06:01 CEST] <hints> hey guys
[23:06:17 CEST] <hints>  im a bit embarrassed to ask this..but ive been stuck with this problem for a day now lol
[23:06:34 CEST] <hints> have a series of RGB png files and I want to create a GIF where transparency_color=black. Is this the right command? ```ffmpeg -i /home/ubuntu/outputs/segments/frame%06d.png -filter_complex "[0:v] scale=320:-1:flags=lanczos,split [a][b]; [a] palettegen=reserve_transparent=on:transparency_color=black [p]; [b][p] paletteuse" /home/ubuntu/outputs/finals.gif```
[23:10:26 CEST] <hints> somehow palettegen=reserve_transparent=on:transparency_color=black isnt turning the black background into transparent
[23:21:25 CEST] <hints> i also posted my question here https://superuser.com/questions/1464819/turning-a-series-of-png-files-into-gif-with-black-transparent-background (so its easier to read)
[00:00:00 CEST] --- Sun Jul 28 2019