[Ffmpeg-devel-irc] ffmpeg.log.20171211

burek burek021 at gmail.com
Tue Dec 12 03:05:01 EET 2017


[00:29:37 CET] <Lunchbox> ok as we were cutting the base of the tree and drilling the hole to fit it onto the christmas tree stand
[00:29:41 CET] <Lunchbox> i thought to myself
[00:29:49 CET] <Lunchbox> oh im encoding my videos using quicksync
[00:29:55 CET] <Lunchbox> is that the problem here?
[00:30:26 CET] <JEEB> the thing says libx264, though? the mediainfo you posted :P
[00:30:35 CET] <JEEB> so didn't really look like QSV encoding
[00:30:51 CET] <Lunchbox> huh
[00:30:55 CET] <Lunchbox> well thats weird
[00:31:03 CET] <Lunchbox> definitely has to be though
[00:31:11 CET] <Lunchbox> i only use like 2% cpu
[00:31:45 CET] <Lunchbox> my computer is nothing fancy either
[00:33:03 CET] <JEEB> anyways, since you remember how the colors looked of what you captured
[00:33:08 CET] <JEEB> go grab mpv from lachs0r's place
[00:33:19 CET] <JEEB> and go ask #mpv how to switch between BT.601 and BT.709
[00:33:28 CET] <JEEB> then check which it is
[00:33:37 CET] <JEEB> and define that in the colorspace filter
[00:35:39 CET] <Lunchbox> its called quicksync h.264 in obs
[00:35:53 CET] <Lunchbox> ask how to switch from 601 and 709 in mpv?
[00:36:05 CET] <Lunchbox> like what it uses when playing a video
[00:36:21 CET] <Lunchbox> or ask how to make it tell me what my video actually is
[00:36:23 CET] <Lunchbox> i'm confused
[00:37:37 CET] <JEEB> ask how to switch between bt.601 and bt.709 to check which it is :P
[00:37:58 CET] <JEEB> the player can't know it any more than me or you because the file's not tagged
[00:38:40 CET] <Lunchbox> wont it still play the video regardless
[00:38:48 CET] <Lunchbox> i dont get what you mean
[00:39:04 CET] <Lunchbox> i thought all of that was determined by the encoding of the video itself
[00:39:27 CET] <JEEB> what gets encoded is YCbCr raw images
[00:39:41 CET] <JEEB> now, the problem is that there's multiple ways of converting that YCbCr to RGB (just like the other way)
[00:39:49 CET] <JEEB> it doesn't affect the decode
[00:40:00 CET] <JEEB> but it does as sure hell affect how you convert that video into RGB to show
[00:40:15 CET] <JEEB> of course, with BT.601 and BT.709 the difference is very small
[00:40:49 CET] <Lunchbox> looks pretty busy in there
[00:40:51 CET] <JEEB> http://avisynth.nl/index.php/Colorimetry#How_can_I_see_if_the_correct_standard_is_used_upon_playback.3F
[00:40:56 CET] <Lunchbox> idk if i'll get a response soon but no worries
[00:41:55 CET] <Lunchbox> so because my video doesnt specify what color matrix it uses or whatever
[00:42:00 CET] <Lunchbox> the players just pick one
[00:42:01 CET] <Lunchbox> lol
[00:42:09 CET] <Lunchbox> i get it now
[00:42:19 CET] <Lunchbox> so you want me to play my video in mpv and see what it says its using
[00:43:08 CET] <JEEB> no
[00:43:11 CET] <therage3> ._.
[00:43:15 CET] <JEEB> I want you to stare at the video YOURSELF
[00:43:19 CET] <JEEB> since the player cannot know
[00:43:26 CET] <JEEB> while YOU know what the video should look like in RGB
[01:02:11 CET] <Lunchbox> brb
[08:39:47 CET] <daksh_> I want to use ffmpeg in Python2 to extract audio from a video. How do I go about it? Is there some reliable python library for ffmpeg or should I run a terminal command using python?
[10:11:19 CET] <atomnuker> Darxus: there's pyav which exposes it
[10:11:34 CET] <atomnuker> https://github.com/mikeboers/PyAV
[12:52:19 CET] <Fyr> guys, does anyone know here why John van Sickle does not include libfdk_aac into his builds?
[12:52:40 CET] <JEEB> because fdk-aac's license only lets you put it together with LGPL stuff
[12:52:41 CET] <JEEB> not GPL
[12:52:46 CET] <JEEB> so you can't do libx264+fdk-aac
[12:52:50 CET] <JEEB> (for example)
[12:52:51 CET] <Fyr> standard openSUSE's FFMPEG is built with it.
[12:53:12 CET] <Fyr> guys in openSUSE know license stuff.
[12:53:24 CET] <Fyr> possibly, they think that it's LGPL compatible.
[12:53:26 CET] <JEEB> I'm pretty sure openSUSE builds a limited thing and most likely without GPL
[12:53:31 CET] <JEEB> it is LGPL compatible
[12:53:36 CET] <JEEB> as I noted
[12:53:38 CET] <bencoh> then they either interpreted it differently or overlooked that issue
[12:53:39 CET] <JEEB> it has an issue with GPL
[12:53:53 CET] <JEEB> the FFmpeg configure lets you configure fdk-aac with LGPL but not GPL
[12:54:00 CET] <bencoh> (or build without x264 and other gpl parts)
[12:54:01 CET] <JEEB> most builds that people distribute are GPL because of x264 or so
[12:54:10 CET] <JEEB> bencoh: opensuse disables most things I think
[12:54:14 CET] <JEEB> at least the official builds
[12:54:26 CET] <JEEB> just like fedora just doesn't distribute FFmpeg or VLC
[12:54:40 CET] <bencoh> JEEB: tbh prefer x264 over libfdk_aac is a bit strange to me
[12:54:41 CET] <bencoh> :)
[12:54:46 CET] <bencoh> preferring*
[12:54:50 CET] <JEEB> lol
[12:54:58 CET] <bencoh> err, the other way around :D
[12:55:16 CET] <JEEB> well, AAC recently became OK to distro it seems. since even fedora now packages fdk-aac
[12:55:42 CET] <JEEB> or I was mistaken, maybe in the next one? aanyways
[12:55:42 CET] <bencoh> together with x264?
[12:55:43 CET] <Fyr> because some patents have expired?
[12:55:48 CET] <JEEB> bencoh: of coure not
[12:55:52 CET] <bencoh> ah, okay
[12:55:55 CET] <JEEB> the license is incompatible with GPL
[12:55:57 CET] <bencoh> then still strange :)
[12:55:58 CET] <JEEB> LGPL is OK
[13:00:38 CET] <Fyr> I downloaded some builds from the Internet on sites where people don't care about license issues. =)
[13:00:45 CET] <Fyr> God bless them
[13:05:37 CET] <BtbN> just use Gentoo and you don't need to care about license bullshit
[13:09:12 CET] <JEEB> Fyr: I kind of wish people would care so that the fdk-aac license bullshit would get solved, or the internal AAC encoder improved further :P
[13:09:37 CET] <Fyr> I'll raise my glass to it.
[13:10:53 CET] <Fyr> I wish the internal AAC to be improved.
[13:16:37 CET] <BtbN> How would you solve that license issue? You'd need to change the GPL for that, and that's not gonna happen.
[13:16:56 CET] <JEEB> no, I mean it's fdk-aac having a custom license
[13:17:18 CET] <JEEB> of course it's also highly unlikely they will change it because it works for GOOG for android
[13:17:50 CET] <BtbN> The FDK license isn't even bad imo. It just happens to be incompatible with the GPL because of some of the more weird requirements of it.
[13:18:14 CET] <JEEB> I don't see "don't add additional requirements" as weird tbh
[13:18:39 CET] <JEEB> which is why the latter part is what would actually fix it (together with people switching to the internal encoder as in my last tests at ~96kbps the internal encoder was not audibly worse for me)
[13:42:06 CET] <Tomaz^> Maybe someone here can help, avformat_open_input returns -5, and I can't for my life figure out what that means, tried av_strerror with both 5 and -5, but they just say "error -5/5 occured" or something along those lines
[13:48:46 CET] <JEEB> av_err2str
[13:48:47 CET] <JEEB> try that one
[13:48:55 CET] <JEEB> and it hsould be the negative one
[13:49:03 CET] <JEEB> also enable more verbose logging then
[14:20:18 CET] <Timmey> Good afternoon, quick question: I'm trying to write progress to stdout. For mac '-progress "/dev/stdout"' works but on debian it doesn't. Anyone got an idea?
[14:45:05 CET] <DHE> debian likely has an old version. that happens a lot unfortunately
[14:47:34 CET] <kr16> hi , attempting to play HEVC 10bit files using Ubuntu 16.04 and Nvidia GT1030, compiled ffmeg with cuda per Nvidia instructions but no luck
[14:47:52 CET] <kr16> i execute ffplay "file name"
[14:49:03 CET] <kr16> Picture is stuttering and all 4 cores are at 100%
[14:49:30 CET] <kr16> Is this a right place to ask for stuff like that or should I try mailing list?
[14:50:06 CET] <Timmey> @DHE I did compile the sources myself, so shouldn't be outdated :[
[14:52:59 CET] <iive> kr16: what version of ffmpeg. are you sure you had yasm/nasm present. hw acceleration is not used by default, have you specified you want it. mpv might be better for video playback.
[14:53:26 CET] <iive> i mean, hwaccel is not used by default for playback.
[14:53:50 CET] <kr16> ffmpeg was pulled from git at Dec 7th
[14:54:24 CET] <kr16> yasm I had to add as requested by ./configure
[14:54:59 CET] <kr16> I am not sure how to specify hw with ffplay
[14:55:44 CET] <kr16> thats what I was afraid of, missing command line options for ffplay
[14:56:08 CET] <kr16> can you give an example for hevc?
[14:57:29 CET] <kr16> did not try mpv , I am not aware of it , start reading now :)
[15:58:07 CET] <artushin> hey guys, anyone happen to have any experience with RTP/RTCP streams to ffmpeg?
[15:58:24 CET] <teratorn> artushin: just ask your question :)
[15:59:16 CET] <artushin> thanks! I've written it up on https://stackoverflow.com/questions/47731788/fixing-a-v-sync-issues-with-rtp-rtcp-sent-from-mediasoup but basically I want to know how to change timestamps on a stream to match the timestamps of a stream that starts a bit later
[16:27:27 CET] <kr16> how would I invoke ffplay command to use hevc or hevc_cuvid decoder?
[16:29:25 CET] <kepstin> kr16: just use mpv instead, it has decent docs on setting up hardware decoding.
[16:29:42 CET] <kepstin> kr16: but that said, I suspect it should be similar to using hardware decoding in the ffmpeg tool.
[16:33:31 CET] <kr16> do I just install mpv from PPA? my ffpmeg is compiled locally without make install
[16:36:10 CET] <sfan5> if you want mpv to link to your local ffmpeg installation you will need to compile it yourself
[17:44:24 CET] <kr16> ok, think I got it , made .deb package from my ffmpeg with cuda and install it, installed mpv (and it did not ask for ffmpeg anymore)
[17:44:50 CET] <kr16> so now I tell mpv to play file, I will need to specify decoder correct ?
[17:59:04 CET] <kr16> so I have h264_cuvid decoder and hevc_cuvid decoder , I am guessing this is what I want to use to get hardware decoding from gt1030
[17:59:38 CET] <kr16> exectuing mpv just use h264 and hvec which kills CPU
[18:02:38 CET] <DHE> for video playback vdpau is another possibility. you might also need the binary nvidia drivers though
[18:08:54 CET] <kr16> i do have those, tried --vo=vdpau which gives same results, CPU 100%
[18:09:14 CET] <kr16> not sure how to use this cuda stuff
[18:10:10 CET] <kr16> ffmpeg shows hevc and hevc_cuvid , cuvid I guess gives hardware support for hevc 10bit
[18:10:51 CET] <iive> are you sure you have hw acceleration working at all?
[18:11:21 CET] <iive> e.g. there is `vdpauinfo` program, see what it tells
[18:12:33 CET] <dystopia_> i have a video an 29.970 and every 5th frame is a duplicate
[18:13:04 CET] <dystopia_> do i just add "-decimate cycle 5" to my line to handle it?
[18:16:28 CET] <DHE> it's a filter, not a commandline option
[18:16:42 CET] <DHE> also note that decimate causes variable framerate
[18:17:19 CET] <dystopia_> oh :(
[18:17:55 CET] <dystopia_> so whats the best way to take it to 23.976 ?
[18:21:18 CET] <kr16> so yes , vdpauinfo shows support for hevc main line but not hevc 10 bit
[18:21:31 CET] <kr16> but thats expected
[18:22:07 CET] <kr16> whole idea of 10bit support was compiling ffmpeg with nvidia cuda
[18:22:27 CET] <kr16> that should give 10bit support (hardware)
[18:25:39 CET] <kr16> this is what I am attempting BTW https://developer.nvidia.com/ffmpeg
[18:33:30 CET] <TheRock2> i heard handbrake is better than ffmpeg, is that true ?
[18:40:04 CET] <durandal_1707> TheRock2: yes, go away
[18:52:07 CET] <microchip_> TheRock2: take your meds so you won't hear voices
[18:58:21 CET] <illegal> So I was trying to convert audio to opus on ffmpeg but problem was that the audio was 5.1channels, which gave me these error, but according to the latest comment none of the workarounds (even the ones I tried) work, is there one which actually works? https://trac.ffmpeg.org/ticket/5718
[19:00:03 CET] <TheRock2> ok, im sorry that i heard this
[19:07:11 CET] <TheRock2> I did not want to raise aggressions here
[19:10:29 CET] <kr16> @TheRock2 Imagine going to Audi forum and asking that you heard BMW is better, what is it that you expect? :)
[19:11:36 CET] <JEEB> TheRock2: handbrake uses FFmpeg's libraries
[19:11:37 CET] <JEEB> QED
[19:13:22 CET] <TheRock2> I'm sorry to hear that
[19:13:44 CET] <JEEB> why? :)
[19:14:08 CET] <JEEB> tl;dr handbrake is probably one of the least retarded graphical interfaces for the FFmpeg libraries
[19:17:43 CET] <Fyr> guys, does anybody know when the developers are going to implement AV1?
[19:18:08 CET] <JEEB> maybe when it's finished?
[19:18:17 CET] <JEEB> it's still in soft freeze and IP review
[19:22:10 CET] <TheRock2> one question
[19:22:17 CET] <TheRock2> codecs like h264, etc.
[19:22:26 CET] <TheRock2> are they reconstructed by reverse engineering?
[19:22:46 CET] <JEEB> things that have actual specifications and official reference test suites don't really need that
[19:22:53 CET] <JEEB> formats that are "proprietary" need that
[19:23:06 CET] <TheRock2> becuse i read handbrake reverse engineered h264
[19:23:14 CET] <JEEB> H.264 http://www.itu.int/rec/T-REC-H.264-201704-I/en
[19:23:16 CET] <TheRock2> and they were the first that had it
[19:23:17 CET] <JEEB> full spec to decode it
[19:23:36 CET] <DHE> there's a (very long) spec document for h264. "annex b" mode is so named because the document's annex B describes it
[19:23:37 CET] <JEEB> then you have left some very important parts out of those sentences you've read
[19:23:41 CET] <DHE> you can download it for free
[19:23:50 CET] <JEEB> DHE: linked already
[19:24:15 CET] <DHE> I've read (part of) it
[19:24:18 CET] <DHE> :)
[19:24:27 CET] <JEEB> you usually just read what you care about
[19:24:33 CET] <JEEB> what you're implementing etc
[19:25:25 CET] <TheRock2> No
[19:25:32 CET] <TheRock2> I read correctly
[19:25:33 CET] <TheRock2> https://en.wikipedia.org/wiki/HandBrake#MediaFork
[19:25:42 CET] <TheRock2> In September 2006, Rodney Hester and Chris Long had been independently working to extract the H.264 video compression format from Apple's iPod firmware (1.2) through reverse engineering before meeting on the HandBrake forum. Since their work was complementary, they began working together to develop an unstable, but still compilable, release of HandBrake supporting the H.264 format.
[19:25:55 CET] <TheRock2> So why they do that, if there is a spec?
[19:26:12 CET] <JEEB> what the fuck :D
[19:26:19 CET] <JEEB> yea, because that thing's been public
[19:26:26 CET] <JEEB> I think that omits something
[19:27:07 CET] <BtbN> that sounds like either bullshit, or they were working on its hw decoder/encoder or something
[19:27:08 CET] <JEEB> also by 2006 we already had the H.264 decoder in FFmpeg as well as an encoder in x264
[19:27:16 CET] <iive> maybe they RE ipod, in order to figure out the constraints of the device.
[19:27:16 CET] <DHE> iirc only a decoder was really specified. encoding has been a ground-up job. maybe they meant an encoder?
[19:27:17 CET] <BtbN> also, h264 on an iPod?!
[19:27:24 CET] <DHE> maybe baseline?
[19:27:30 CET] <DHE> does the iPod have a camera?
[19:27:34 CET] <BtbN> no
[19:27:37 CET] <JEEB> yea, probably baseline H.264 at that point
[19:27:45 CET] <JEEB> and yes, figuring out the limitations would make sense
[19:27:53 CET] <JEEB> or if they for some reason started their own encoder project
[19:28:02 CET] <JEEB> which at the point of 2006 already sounds like question marks
[19:28:18 CET] <JEEB> because x264 was already out there (my teenage dumb self used it)
[19:29:12 CET] <ritsuka> one model of the ipod nano had a camera
[19:29:14 CET] <TheRock2> maybe they didn't know about the spec
[19:29:21 CET] <BtbN> highly unlikely
[19:29:32 CET] <JEEB> https://web.archive.org/web/20160611174745/https://trac.handbrake.fr/wiki/HandBrakeHistory
[19:29:35 CET] <JEEB> ok
[19:29:39 CET] <JEEB> this sounds more like they wanted to know how to package it
[19:29:43 CET] <JEEB> for the iPod
[19:30:02 CET] <JEEB> (and/or the limitations)
[19:30:20 CET] <JEEB> and yes, > Apple's new uuid atom
[19:30:22 CET] <ritsuka> yes, it was just an additional atom in the mp4 container
[19:30:23 CET] <JEEB> so that's MOV/MP4
[19:30:31 CET] <ritsuka> to make it work on the ipod
[19:30:34 CET] <JEEB> yup
[20:02:49 CET] <kr16> so ffplay -vcodec hwec_cuvid works and mpv --hwdec-codecs=hevc_cuvid also work, beautiful , now I need 4k TV :)
[20:03:21 CET] <BtbN> that ffplay line makes no sense.
[20:05:31 CET] <kr16> hewc_cuvid
[20:05:37 CET] <kr16> typo :)
[20:05:40 CET] <sfan5> the mpv line doesn't either: hwdec-codecs denotes the codecs that will be hwdecoded, not which hwdecoders to use (it has a sane default value anyway)
[20:06:00 CET] <BtbN> that does not make any more sense
[20:06:14 CET] <BtbN> There is nothing in ffmpeg called that way
[20:06:17 CET] <BtbN> even ignoring the typos
[20:06:27 CET] <sfan5> for mpv you want --hwdec=cuda instead
[20:06:29 CET] <kr16> you need cuda compiled
[20:07:03 CET] <BtbN> it's either -hwaccel nvdec or -c:v hevc_cuvid for the "legacy" decoder.
[20:09:04 CET] <kr16> Failed to set value 'nvdec' for option 'hwaccel': Option not found
[20:09:26 CET] <BtbN> your ffmpeg is too old.
[20:09:58 CET] <BtbN> Or you're using the option wrong. On the output or so
[20:10:07 CET] <kr16> pulled from git last Thursday
[20:13:18 CET] <kr16> anyway it's working ffplay -vcodec hevc_cuvid
[20:13:31 CET] <BtbN> -c:v
[20:13:51 CET] <BtbN> And the decoders called cuvid are legacy and might, at some point in the future, be removed
[20:14:50 CET] <kr16> what would be used instead
[20:15:32 CET] <BtbN> nvdec.
[20:16:02 CET] <kr16> I see, should it be an option to pick already?
[20:16:23 CET] <BtbN> It's a native hwaccel
[20:16:32 CET] <BtbN> turn it on like I just told you.
[20:18:22 CET] <buttocks> hello im a pleb and i need help D:
[20:19:23 CET] <buttocks> ive been trying to dl a file from fite.tv i purchased and i am trying to figure out how i can supply uid and password in the command line. i am currently getting a 403 message
[20:20:25 CET] <kr16> I dont see -hwaccel  option for ffplay
[20:22:27 CET] <BtbN> no idea about ffplay
[20:22:30 CET] <BtbN> it might plain not support it
[20:22:37 CET] <BtbN> it's not meant as a real player
[20:38:11 CET] <kr16> mpv --hwdec=cuda gives me an error, do I need manually compile it?
[20:38:43 CET] <JEEB> hwdec=help should give you teh alternatives available in your build
[20:42:27 CET] <kr16> yeah it does not list cuda as an option
[21:23:33 CET] <kr16> OK , compiling mpv did the trick, very cool, thx guys
[22:36:29 CET] <alexpigment> has anyone had any experience encoding with h264_videotoolbox on macOS?
[22:37:04 CET] <alexpigment> it says "no device available for encoder", but i'm not sure what the requirements are
[22:37:42 CET] <alexpigment> i've got a macbook (non-pro) that can do airplay mirroring, so I'm assuming that it has a valid videotoolbox encoder
[22:37:46 CET] <alexpigment> (intel quick sync)
[23:46:42 CET] <alexpigment> re: earlier, it turns out videotoolbox has the same dumb meaningless warning as quick sync: https://trac.ffmpeg.org/ticket/6492
[23:47:05 CET] <alexpigment> also, as far as I can tell, -b:v and -q:v do nothing
[23:47:22 CET] <alexpigment> -maxrate is the only bitrate control that seems to work from what i can tell
[23:50:25 CET] <alexpigment> nm; i had a -b:v 0 later in my command ;)
[23:51:00 CET] <alexpigment> still no -q:v though :(
[00:00:00 CET] --- Tue Dec 12 2017


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