[Ffmpeg-devel-irc] ffmpeg.log.20191023

[burek]

[05:34:29 CEST] <MoziM> are there changes in opencv4 that make it unsafe to add to ffmpeg's configure file?
[06:41:45 CEST] <Diag> Simple question, assuming i have hdyc coming in, whats the best color space to convert to for playback on rgb screens
[07:03:21 CEST] <kingsley> Do you happen to know of a command line option that limits how many cores ffmpeg uses to render .webm?
[07:03:36 CEST] <kingsley> I tried
[07:03:42 CEST] <kingsley> -threads
[07:03:57 CEST] <kingsley> -filter_threads and
[07:04:15 CEST] <kingsley> -filter_complex_threads
[07:05:09 CEST] <kingsley> but they all seem to me to use every CPU core available.
[08:01:59 CEST] <MoziM> cpulimit -l 50 -v ffmpeg....
[09:10:51 CEST] <YellowOnion> my ffmpeg consistently stops working after 35mins of streaming to a rtmp, "Non-monotonous DTS in output stream 0:0; previous: 2147423, current: -2147484; changing to 2147423"
[09:32:30 CEST] <YellowOnion> I think it's the concat filter causing this issue....
[09:33:20 CEST] <durandal_1707> no, your input have bad timestamps
[09:38:54 CEST] <YellowOnion> no it's concat filter, it's fine without it.
[09:39:05 CEST] <YellowOnion> doesn't matter what the input file is.
[10:14:03 CEST] <durandal_1707> YellowOnion: your bug report is invalid
[10:15:53 CEST] <YellowOnion> durandal_1707, the log file is 17MB what am I supposed to do with it.
[17:56:02 CEST] <dmsilva> Hi, we are currently using ffmpeg 4.0.4 and would like to mitigate the vulnerability mentionned here https://nvd.nist.gov/vuln/detail/CVE-2019-17539.Is applying the commit here https://github.com/FFmpeg/FFmpeg/commit/8df6884832ec413cf032dfaa45c23b1c7876670c to the ffmpeg version I am using is sufficient?
[17:57:52 CEST] <dmsilva> I messed up the link for the CVE. here it is:  https://nvd.nist.gov/vuln/detail/CVE-2019-17539
[17:59:22 CEST] <sc_> hello, can someone explain the reason ffmpeg relies on unbound?
[18:04:58 CEST] <kepstin> sc_: it doesn't, but certain uses of ffmpeg might need the ability to resolve dns, however your os is set up to do that
[18:05:51 CEST] <DHE> or it may use some 3rd party library that itself uses unbound
[18:07:08 CEST] <sc_> thanks, I found it odd homebrew ffmpeg listed it as a dependency...
[19:56:56 CEST] <phobosoph> So my hikvision webcam streams in yuvj420p.
[19:57:07 CEST] <phobosoph> Is there an option to let it stream in yuv420p?
[19:57:11 CEST] <phobosoph> Is there a difference anyway?
[19:57:22 CEST] <phobosoph> I stream yuvj420p to youtube and I don't notice any oddities
[19:57:38 CEST] <phobosoph> do colours look better with yuv420p? is it more compatible?
[19:57:39 CEST] <phobosoph> :)
[20:00:16 CEST] <klaxa> yuv420p has more colors than yuvj420p iirc
[20:00:46 CEST] <klaxa> ah, the other way around
[20:00:51 CEST] <klaxa> https://wiki.videolan.org/YUV#J420
[20:18:17 CEST] <kepstin> phobosoph: the only problem is that iirc browsers don't support yuvj420p playback in general, so the videos might appear overly-contrasty, with loss of detail in shadows/highlights
[21:28:46 CEST] <phobosoph> kepstin: can I somehow simulate this? so I can see the difference?
[21:30:04 CEST] <phobosoph> frame=66455 fps= 11 q=-1.0 size= 1665277kB time=00:36:55.18 bitrate=6158.4kbits/s speed=0.37x
[21:30:05 CEST] <phobosoph> oh no
[21:30:12 CEST] <phobosoph> why is the speed going down, again? :(
[21:31:14 CEST] <phobosoph> https://pastebin.com/9WRV3AZv
[21:31:18 CEST] <phobosoph> that's the ffmpeg command used
[21:31:23 CEST] <phobosoph> I don't see anything wrong with it :/
[21:34:25 CEST] <kepstin> phobosoph: your first task is to rule out network or cpu bottlenecks.
[21:38:46 CEST] <phobosoph> kepstin: right, how can I do that? :/
[21:38:48 CEST] <phobosoph> speedtest?
[21:48:50 CEST] <phobosoph> hmmm
[21:49:02 CEST] <phobosoph> kepstin: is the command in the nopaste link looking good?
[21:50:21 CEST] <kepstin> nothing obviously wrong, which is why the issue is most likely due to external circumstances.
[21:50:47 CEST] <phobosoph> I see
[21:50:49 CEST] <phobosoph> thanks
[21:50:50 CEST] <phobosoph> :/
[21:50:58 CEST] <phobosoph> thing is that ffmpeg happily sends the data
[21:51:03 CEST] <phobosoph> usually with 1x speed
[21:51:07 CEST] <phobosoph> I am also using the newest ffmpeg
[21:53:02 CEST] <phobosoph> "RTP H.264 NAL unit type 25 is not implemented."
[21:53:05 CEST] <phobosoph> but it still works
[22:08:19 CEST] <jokoon> Is there a standard to store metadata in a video file, like an image? I'm thinking about storing a thumb atlas to display on the video progress bar...
[22:08:38 CEST] <jokoon> apparently it would be expensive to do it when you open a video file with videolan for example
[22:09:32 CEST] <jokoon> what do video website do for this? I guess ffmpeg already does generate previews?
[22:21:36 CEST] <DHE> youtube has their own custom player, and they are the video source, so they make their own thumbnails
[22:32:19 CEST] <jokoon> yeah but other web video solution might use ffmpeg
[22:35:03 CEST] <furq> obviously you can use ffmpeg (or anything) to generate them, but their player and frontend is all custom
[22:40:56 CEST] <jokoon> what else can you tell me about their tools?
[00:00:00 CEST] --- Thu Oct 24 2019