[Ffmpeg-devel-irc] ffmpeg.log.20150504

[burek]

[02:04:42 CEST] <Prelude2004c> hey guys.. anyone know what the best playout software is for schedules and just simple playout ? Does ffmpeg have any playout UI ?
[10:35:21 CEST] <rcombs> How do I patch KDE2 under FreeBSD?
[10:36:21 CEST] <spaam> KDE2?!
[10:36:22 CEST] <spaam> wow
[10:36:27 CEST] <spaam> thats old
[10:36:45 CEST] <spaam> 13 years ago the last stable was released.
[10:58:02 CEST] <danboid> Is it not possible to seek to a point in a video by specifying a percentage of the way through the clip?
[11:41:51 CEST] <zynx_> what is the most important to running ffmpeg as a transcoder? is i Ghz or Cache?
[11:45:32 CEST] <Mavrik> GHz and number of cores
[11:46:26 CEST] <JamJams> I'm having a really hard time understanding the crop filter. How do I crop 2px of black from the right hand side of my video :(
[11:49:29 CEST] <Mavrik> JamJams, how big is your input video in pixel terms_
[11:49:31 CEST] <Mavrik> ?
[11:50:02 CEST] <JamJams> It's a 1080p recording, I only want to crop those 2px off
[11:50:06 CEST] <JamJams> I don't want to resize or anything
[11:50:40 CEST] <Mavrik> JamJams, 1080p isn't really a useful name for that
[11:50:51 CEST] <Mavrik> you need to provide a box for output video so you need to know your resolution
[11:50:55 CEST] <Mavrik> so, again
[11:51:00 CEST] <Mavrik> how big is your video in pixel terms?
[11:51:17 CEST] <JamJams> 1920x1080
[11:51:36 CEST] <Mavrik> so if you crop off two pixels your output will be 1918x1080
[11:51:39 CEST] <JamJams> Correct
[11:51:44 CEST] <JamJams> I have no idea how to do that
[11:51:53 CEST] <Mavrik> crop=1918:1080:0:0
[11:52:09 CEST] <Mavrik> meaning "crop a box sized 1918x1080 which is positioned at 0,0"
[11:52:13 CEST] <JamJams> How is it going to know to crop those 2px off the right
[11:52:17 CEST] <JamJams> And not the left
[11:52:29 CEST] <Mavrik> because you're saying "X of the box is 0, and Y of the box is 0"
[11:52:56 CEST] <JamJams> So what would I do if I wanted to crop off the left and not the right?
[11:53:15 CEST] <Mavrik> you'd move the "cropped box" two pixels to the right
[11:53:21 CEST] <Mavrik> 1918:1080:2:0
[11:55:38 CEST] <JamJams> I see
[11:56:10 CEST] <JamJams> And if I wanted to crop 2 of both it would be 1916:1080:2:0
[11:56:12 CEST] <JamJams> Right? :)
[11:56:28 CEST] <Mavrik> yep
[11:56:51 CEST] <Mavrik> just note that some old crappy hardware decoders don't like "non-standard" sized video ratios
[11:57:10 CEST] <Mavrik> so if you get wierd playback problems on chinese crap it's because it wants a 1920x1080 not 1916x1080 video :P
[11:58:15 CEST] <JamJams> Yep
[11:59:17 CEST] <JamJams> Is there a way to just sorta automate it a bit better I saw you can use h and w in the parms
[11:59:30 CEST] <Mavrik> yeah, you can write an expression
[11:59:33 CEST] <JamJams> So can't I make it like w-2:h:2:0
[11:59:34 CEST] <JamJams> Or something
[11:59:45 CEST] <Mavrik> by default the cropbox is centered anyway
[11:59:55 CEST] <JamJams> I'm really use to the avs crop() filter
[12:00:05 CEST] <JamJams> So this is very confusing to learn
[12:00:09 CEST] <Richlv> when extracting frames from a video, can i extract sequential frames from multiple videos ?
[12:00:12 CEST] <Mavrik> JamJams, yeah
[12:00:28 CEST] <Mavrik> crop=iw-2:ih:2:0 should work
[12:00:30 CEST] <Richlv> let's say video1 would provide frames 1-100, then video2 101-153
[12:00:51 CEST] <Mavrik> crop=w=iw-4:h=ih should cut 2 pixels on each size
[12:00:53 CEST] <Mavrik> *Side
[12:00:55 CEST] <Mavrik> etc.
[12:01:04 CEST] <JamJams> I see
[12:01:07 CEST] <JamJams> Very intresting
[12:01:12 CEST] <Richlv> (without concatenating them in a separate file first)
[12:01:33 CEST] <Richlv> and without extracting them separately and scripting the numbering :)
[12:01:55 CEST] <Richlv> i tried passing multiple files in a couple of ways, but that did not seem to work
[12:02:13 CEST] <JamJams> If you use -ss offset -i 1.mkv -ss offset -i 2.mkv it may work
[12:02:35 CEST] <JamJams> ffmpeg isn't frame accurate in most cases though so I wouldn't count on it doing exactly
[12:03:41 CEST] <Richlv> oh, i extract them every 2 or 3 seconds anyway
[12:03:51 CEST] <Richlv> i just want the numbering to continue from another video
[12:03:56 CEST] <JamJams> Oh I see
[12:04:07 CEST] <JamJams> I think you'd have to cat them together
[12:04:21 CEST] <Richlv> thanks, in that case scripting might be easier
[12:04:25 CEST] <Richlv> and much faster :)
[12:04:29 CEST] <JamJams> You could try cat 1.mkv 2.mkv | ffmpeg -i -
[12:04:47 CEST] <Richlv> well, these ar MOV
[12:04:55 CEST] <JamJams> Yeah I don't think it would work with that
[12:05:00 CEST] <Richlv> i tried concatting them and ffmpeg complained
[12:05:11 CEST] <JamJams> Yeah with some formats it ignores the header doubling
[12:05:23 CEST] <JamJams> Like .ts and .mpg
[12:06:23 CEST] <Richlv> i'll go with a script then.
[12:06:33 CEST] <Richlv> starting number for frames can't be specified, can it ?
[12:06:40 CEST] <Richlv> at least manpage does not seem to mention anything like that
[12:07:56 CEST] <JamJams> I don't think so no
[12:27:54 CEST] <zynx_> so E5-2630v2 will be good option for transcoding ?
[13:27:52 CEST] <JamJams> zynx_ The CPU? Not bad an i7 is better however
[13:57:49 CEST] <zynx_> JamJams well is for a server envirement
[13:58:06 CEST] <JamJams> E5 should be fine then
[13:58:35 CEST] <JamJams> What kind of encoding x264?
[13:58:53 CEST] <JamJams> desktop hardware works best for x264 since it has more clocks per core not more threads per core
[13:59:14 CEST] <JamJams> And you want more clock not more threads since x264 gets worst quality the more threads you enable
[14:02:09 CEST] <__jack__> well, worst quality .. nothing special
[14:11:22 CEST] <Mavrik> yeah, we use 16 core machines for x264 and it's just fine
[14:11:33 CEST] <Mavrik> 16/32 thread that is
[14:11:47 CEST] <Mavrik> a couple of 24/48 as well
[14:37:53 CEST] <xer0> hello
[17:28:07 CEST] <termos> when setting thread_count on my encoding context, is that honored by x264? I'm setting it to 4 but nine encoding are spawning ~800 threads according to my OS
[17:28:30 CEST] <termos> this is a 64 core CPU, so I wonder if thread_count is working as some kind of multiplier?
[17:42:36 CEST] <Mavrik> termos, thread count gets passed to x264 yes
[17:42:51 CEST] <Mavrik> but those are only encoder threads
[18:06:06 CEST] <Mista-D> when converting file to 1 fps slide show I get extra 1 sec in duration. Audio is perfect duration but video stream gets 1 sec longer. Using "-vf fps=1". Any ideas please?
[18:15:36 CEST] <Mista-D> Anyway to crop video track's duraiotn to match audio track's duration exactly?
[20:25:37 CEST] <edoardo> hello!
[20:26:02 CEST] <edoardo> How can i dump to a text file all the info about the codec used for the input file?
[20:26:23 CEST] <edoardo> -f ffmetadata works well but gets only metadata, and not codec info
[20:32:40 CEST] <lordkrondor> use ffprobe?
[20:32:46 CEST] <lordkrondor> with -show_streams ?
[20:35:58 CEST] <edoardo> lordkrondor: thanks!
[20:36:10 CEST] <edoardo> how may i show the metadata now, and not dump it to a file?
[20:36:22 CEST] <edoardo> using -f ffmetadata hangs ffprobe
[20:50:47 CEST] <edoardo> god how much i hate libav
[21:05:38 CEST] <micechal> when encoding with ffmpeg, why does it start displaying processed frames from 25/26 rather than from 0 or 1?
[21:39:23 CEST] <icucode> Is it possible to select a specific stream/track to play from an RTSP server using ffmpeg?
[21:40:43 CEST] <icucode> I have a problem with an RTSP server that say it have two streams/tracks but when sending SETUP for the second one it returns "DESCRIBE failed: 404 Stream Not Found"
[21:41:32 CEST] <icucode> It plays fine with VLC and by inspecting the traffic I can see that VLC only invokes SETUP/PLAY for the first stream and ignores the second one.
[00:00:00 CEST] --- Tue May  5 2015