[Ffmpeg-devel-irc] ffmpeg.log.20160513

[burek]

[01:27:32 CEST] <voltagex> this is a silly question probably, but will an i7 2600k always outperform an i7 6560U in encoding performance with libx265 due to higher clock speed? I'm seeing a 30-50% encoding speed increase in favour of the 2600k. Guess Skylake doesn't help that much?
[01:39:29 CEST] <furq> voltagex: it's more down to TDP than clock speed
[01:39:47 CEST] <ploc> hi I'm using the following ffmpeg command : ffmpeg -i "${inputVideo}" \   -c:a copy               \   -c:v libx265            \   -crf 28                 \   -preset:v medium        \   -profile:v main         \   "${outputVideo}"
[01:40:05 CEST] <ploc> and I get an error : [libx265 @ 0x942e1e0] [Eval @ 0xbfa18388] Undefined constant or missing '(' in 'main' [libx265 @ 0x942e1e0] Unable to parse option value "main" [libx265 @ 0x942e1e0] Error setting option profile to value main.
[01:40:37 CEST] <ploc> I'm using ffmpeg version 2.8.6-1~bpo8+1
[01:47:37 CEST] <Rudde> Hey
[01:47:41 CEST] <llogan> ploc: there is no -profile private option for libx265 in ffmpeg
[01:48:12 CEST] <llogan> and i doubt it will work via -x265-params: http://x265.readthedocs.io/en/default/cli.html#profile-level-tier
[01:48:27 CEST] <Rudde> Is it possible to pass multipler values to -ss for points to make screenshots?
[01:49:15 CEST] <ploc> llogan: ok, it is strange because I've just read it in a french magazin which is usually reliable
[01:49:50 CEST] <llogan> you can use --profile is you use x265 binary directly
[01:50:09 CEST] <llogan> but just try without it. it will probably just choose main anyway
[01:50:35 CEST] <llogan> Rudde: probably easier to use select filter
[01:51:43 CEST] <Rudde> I would like to to be fast and just get 3, 4 or 5 fullscreen uncompressed png screenshots from a video want it to be very fast and hopefully meanyfull screenshots? And my experience it that select is very slow?
[01:52:07 CEST] <llogan> -vf "select='eq(t,0)+eq(t,25)+eq(t,50)+eq(t,75)'" -vsync vfr output_%03d.png
[01:52:15 CEST] <llogan> yes, it is probably slower than -ss
[01:52:46 CEST] <ploc> llogan: you're right it does work without the profile parameter (maybe the guy is using libav???)
[01:53:46 CEST] <Rudde> Would I be better of by just running with -ss 3-5 times?
[01:54:09 CEST] <llogan> ploc: you can remove preset too since medium is the default
[01:54:26 CEST] <llogan> Rudde: i don't know. compare both methods and time it
[01:55:07 CEST] <Rudde> seems like select us extrmly slow, even with video in ram
[01:57:23 CEST] <furq> `-vf select='gt(scene\,0.4)' -frames:v 4 out%02d.png` will probably do a better job of getting "meaningful" screenshots
[01:57:29 CEST] <furq> it'll still be slow though
[01:59:35 CEST] <ploc> llogan: according to your link, profiles are supported in h265: The following profiles are supported in x265.
[01:59:38 CEST] <Rudde> That gave me 4 black screens :P
[01:59:44 CEST] <Rudde> where the first one gave me only one
[01:59:52 CEST] <Rudde> but all seemed to be from the very beginning of the clip
[02:01:32 CEST] <llogan> ploc: yes, but that option says "CLI ONLY: API users must blah blah blah".
[02:02:11 CEST] <ploc> llogan: how do you use ffmpeg without CLI?
[02:03:14 CEST] <llogan> it's referring to x265 cli
[02:09:40 CEST] <voltagex> furq: any more information? Do you mean thermal throttling?
[02:11:05 CEST] <furq> i mean the fact that one is a laptop cpu and one is a desktop cpu
[02:11:41 CEST] <furq> the clock speed and architecture don't really mean anything when you're comparing an 85 watt cpu with a 15 watt one
[02:33:42 CEST] <Rudde> What is the difference between -vframes and -frames?
[08:30:49 CEST] <LigH> Hi.
[08:33:02 CEST] <LigH> According to Wikipedia, libavcodec shall support decoding CineForm HD (GoPro). But in the full help of an ffmpeg recently built with a suite in "non-free" mode, claiming to support all available codecs, I could not find it mentioned as supported format. Does it require a specific build switch they may have forgotten to include?
[08:37:42 CEST] <relaxed> LigH: ffmpeg -codecs 2>&1| grep Cineform
[08:40:58 CEST] <furq> LigH: anything newer than 3.0 should have it
[08:42:25 CEST] <furq> what a nice young man
[08:42:52 CEST] <LigH> Sorry, our ISP has technical issues. This is a "No-DSL area".
[08:42:59 CEST] <furq> 07:40:58 ( furq) LigH: anything newer than 3.0 should have it
[08:43:44 CEST] <LigH> ffmpeg version N-79976-g34a5e64-g97946b2+1
[08:44:06 CEST] <LigH> auto-built yesterday
[08:44:08 CEST] <relaxed> LigH: did the command I gave you return anything?
[08:44:37 CEST] <relaxed> if you have support it will return " D.V.L. cfhd                 Cineform HD"
[08:44:54 CEST] <LigH> Yes, that's included.
[08:45:17 CEST] <relaxed> then you're good to go
[08:45:34 CEST] <LigH> So the codecs list is not included in the full help...
[08:45:46 CEST] <relaxed> correct
[08:46:11 CEST] <relaxed> well, maybe cfhd is (the name of the decoder)
[08:46:15 CEST] <furq> it isn't
[08:46:42 CEST] <relaxed> ffmpeg -h decoder=cfhd
[08:46:43 CEST] <furq> "-codecs" is mentioned in full help though
[08:47:01 CEST] <furq> so it's pretty much your fault for not reading all 8405 lines of -h full
[08:47:22 CEST] <furq> or however many your build has. probably more if it supports "all available codecs"
[08:49:31 CEST] <LigH> If I want "full help", somehow I expected that the result of "-codecs" was included there as well...
[08:50:59 CEST] <relaxed> "-decoders           show available decoders" is near the top of ffmpeg -h
[08:51:50 CEST] <LigH> I expect all this to be included in "-help full", or this doesn't really mean "full". ;)
[08:54:00 CEST] <LigH> But okay. CFHD should be supported for decoding. So it may also be available in related projects, like LAV FIlters.
[08:54:10 CEST] <LigH> Provided the ffmpeg base is current.
[09:02:00 CEST] <LigH> \o
[13:18:53 CEST] <Dariush> Hi. I want to crop some videos, but I don't want to reencode them due to size. Is it possible to set a viewport or something so that the unwanted parts are not shown?
[13:20:43 CEST] <JEEB> mp4 has stuff like that but I'm pretty sure very few things actually support it
[13:20:58 CEST] <JEEB> matroska kind of has stuff like that, but that is a feature that is very badly defined
[13:21:07 CEST] <JEEB> so you should refrain from using it
[13:23:42 CEST] <Dariush> oh, all right. thanks ;)
[14:28:34 CEST] <gml> Hello, I'm trying to stream the video from my webcam to IIS's Live Smooth Streaming. When I open the stream using VLC, the video starts playing from the moment I executed the ffmpeg command. What I'm trying to achieve is to make clients see the playback from the moment they connect to the stream, not from the very beginning. How can I achieve this? This is my command and its initial output: http://pastebin.com/nj65AMSj
[15:57:22 CEST] <thunfisch> hey, trying to capture with decklink module and 10.6.4 driver at 720p50 over hdmi on a decklink mini recorder - only getting color bars. source is 100% setup correctly. anyone else have this problem?
[18:09:29 CEST] <nMaib0> why can't libopus change the sample rate to 44.1 KHz?
[18:13:28 CEST] <vade> functionally, is there any difference between using libswresample or an avfilterchain with aresample=N and aformat=FMT ?
[18:17:19 CEST] <JEEB> I think aresample/aformat internally use swresample
[18:17:27 CEST] <JEEB> or at least they should be using that
[20:46:09 CEST] <dbugger> Hello guys and girls
[20:50:44 CEST] <dbugger> I have a question: I get a video as input with an unknwon resolution. I use this for cropping: "[0:v]crop=w=320:h=240[v0c]". The problem here is that I would like to resize first, so that either the width or the match one of those 2 coordinates, and the crop the rest. The problem is that I cant know before hand if the video will be taller or wider... how could I do this?
[20:51:55 CEST] <DHE> there is some formula support in ffmpeg. you could write some very basic logic for it
[20:55:37 CEST] <dbugger> I have no idea how to do that...
[21:06:03 CEST] <xintox> is it possible to tell ffmpeg to pick a specific stream from a manifest file?
[21:06:18 CEST] <xintox> i have to use the manifest file because it sets cookies
[21:06:35 CEST] <xintox> using m3u8
[21:14:43 CEST] <klaxa> dbugger: maybe see: https://www.ffmpeg.org/ffmpeg-filters.html#scale-1 ?
[21:14:53 CEST] <klaxa> oh wait...
[21:14:58 CEST] <klaxa> with cropping... that's a tough one
[21:25:22 CEST] <dbugger> klaxa, yeah...
[21:26:12 CEST] <klaxa> if the file is not "streamed" you could read it first with ffprobe (or ffmpeg -i) extract the video's dimensions, do some calculations with those and use these as parameters for ffmpeg
[21:36:53 CEST] <dbugger> Already working on a solution... wait
[21:47:57 CEST] <dbugger> Great, found it :)
[21:48:00 CEST] <dbugger> Thanks all anyway :)
[22:52:31 CEST] <midgetspy> ffmpeg -ss 600 -i test.mkv -y -vframes 1 -an out.png gives me http://imgur.com/ovFU5iB but if I watch the video myself I don't see any such corruption. is there an option I'm missing to fix this?
[23:39:01 CEST] <SleepyPikachu> I'm trying to create a photo slideshow from *.jpg where each image shows for 10s on a loop and the video is as long as the back track audio. I can't figure out how to make image show for 10s
[23:39:57 CEST] <SleepyPikachu> This is what I've tried so far: ffmpeg -loop 1 -pattern_type glob -i '*.jpg' -i back.mp3 -c:v libx264 -c:a copy -shortest out.mp4
[00:00:00 CEST] --- Sat May 14 2016