[Ffmpeg-devel-irc] ffmpeg.log.20160918

[burek]

[00:51:19 CEST] <Enlight_Ingress> Can you rip cds to flac with ffmpeg
[00:51:40 CEST] <c_14> You can, but it's probably not the best tool for the job.
[00:52:35 CEST] <Enlight_Ingress> Im running mac os sierra and XLD doesnt do flac now for some reason
[00:53:39 CEST] <furq> Enlight_Ingress: https://sourceforge.net/p/xld/tickets/371/
[00:54:58 CEST] <Enlight_Ingress> Thanks
[01:04:12 CEST] <durandal_1707> c_14: what is wrong with ffmpeg and flac?
[01:06:01 CEST] <c_14> Nothing, it's just that audio cds tend to consist of several tracks and ffmpeg does not process these (to i.e. split each track into a single flac) nor does it process audio cd track metadata
[01:09:32 CEST] <Chloe> c_14: can it do it with a .cue?
[01:10:04 CEST] <c_14> As far as I'm aware, ffmpeg does not have support for playlists at all (beyond rudimentary concat support)
[01:10:28 CEST] <c_14> You could probably achieve some sort of magic using the segment muxer
[01:11:57 CEST] <Chloe> I meant splitting a flac using a cue. Sorry, I should have been more clear.
[01:12:06 CEST] <furq> not as far as i can tell
[01:12:17 CEST] <furq> there are already good tools for that though
[01:12:23 CEST] <furq> although not so much on *nix
[01:12:56 CEST] <c_14> You can script it
[01:13:19 CEST] <c_14> Or write a program wrapping the libraries to do it, but there is no such built in functionality.
[02:12:34 CEST] <tincode> I have some really old videos from 1993. Seem to be from a video Video-8 cam. Don't know what model. Is there any way test the clips and see if that cam had a rolling shutter ?
[02:14:16 CEST] <tincode> Some algorithms for image stabilising (shaking) wont work right if the cam has a rolling shutter, that is why I ask.
[02:15:07 CEST] <tincode> CCD VS CMOS sensors.
[03:01:07 CEST] <ossifrage> I wonder if I could convince a browser (chrome) to display a single h.264 i-frame (elementary stream) without a bunch of pain?
[04:34:59 CEST] <Hauke__> Hi, is somebody online that can help me with FFmpeg? I want to join two videos but have some problems...
[06:06:01 CEST] <TeKKiE> Hello everyone. I know you've probably been beaten to death with this question, but if you could simply provide a link for me to learn, that would be okay too. Question follows:
[06:06:37 CEST] <TeKKiE> I would like to re-build my ffmpeg with nvenc support, as I'd like to offload encode/decode to my graphics card that doesn't do very much in linux.
[06:07:05 CEST] <TeKKiE> I've been to ubuntuforums, as well as some forks in github, and most if not all have different suggestions.
[06:08:17 CEST] <TeKKiE> Bottom line: I want to use my GTX 970 to encode streams for tvheadend. I'm hoping that by using nvenc to encode streams will yield better quality for my streams.
[10:39:56 CEST] <markvandenborre> I'm ingesting two rtmp streams with ffmpeg and real time encoding it into a picture-in-picture stream
[10:40:31 CEST] <markvandenborre> but ffmpeg gets confused when one of the two rtmp streams drops
[10:41:56 CEST] <markvandenborre> I know I could use something like open broadcast studio to get rid of this confusion, but I absolutely want to have this headless
[10:42:07 CEST] <markvandenborre> and using FOSS software
[10:42:21 CEST] <markvandenborre> so I wonder about the best way to achieve that
[10:43:12 CEST] <markvandenborre> any hints are more than welcome!
[10:56:41 CEST] <durandal_1707> markvandenborre: command?
[11:00:23 CEST] <BtbN> markvandenborre, if one of the streams goes done, for ffmpeg it ended. It won't pick it up again without a restart.
[11:01:07 CEST] <markvandenborre> BtbN: yup... I wonder what the easiest way around it is
[11:01:36 CEST] <BtbN> Modify ffmpeg.c to keep trying to re-open its inputs.
[11:01:55 CEST] <BtbN> But even then, the remaining filter and de/encode chain might be confused because of the stream-restart
[11:04:22 CEST] <markvandenborre> some kind of daemon needed in between I guess to solve this cleanly
[11:04:46 CEST] <markvandenborre> ?
[11:06:44 CEST] <retard> maybe some kind of streaming server that supports fallbacks
[11:08:49 CEST] <markvandenborre> basicly, it is _extremely_ likely that if one ingested stream goes down, both go down simultaneously
[11:09:26 CEST] <markvandenborre> in fact, I can't even imagine any situation where that would not be the case
[11:09:47 CEST] <markvandenborre> except for software bugs of course
[11:10:21 CEST] <markvandenborre> it's more like: power problem at the stream source etcetera
[11:10:46 CEST] <markvandenborre> there's a streaming server on that side that will keep on spewing out streams, even empty ones
[11:11:52 CEST] <markvandenborre> both streams get thrown at ffmpeg by the same machine
[11:12:16 CEST] <markvandenborre> but that streaming server just has not got the crunching power to encode the picture in picture stream
[11:13:18 CEST] <markvandenborre> durandal_1707: sorry, just seeing your message right now
[11:13:47 CEST] <markvandenborre> this is in many ways still a conceptual discovery voyage I'm afraid
[11:14:01 CEST] <markvandenborre> (in preparation for https://fosdem.org video streaming btw)
[11:28:28 CEST] <BtbN> It would probably be the easiest solution to write your own application, that has a decoupled input, and inserts "No Signal" frames when it's down.
[11:28:32 CEST] <BtbN> And keeps trying to re-open it
[11:34:46 CEST] <markvandenborre> BtbN: not aware of anything like that in the FOSS world?
[11:35:58 CEST] <markvandenborre> because this seems to be exactly what obs does, only not headlesss
[11:36:25 CEST] <BtbN> OBS is a stream compositing software, for capturing games and applications and stuff
[11:36:45 CEST] <BtbN> you could emulate this by opening two video players, have them in endless retry mode, and screen-cap both of them.
[11:37:32 CEST] <markvandenborre> :-)
[11:38:19 CEST] <markvandenborre> thx
[11:38:43 CEST] <markvandenborre> btw, we have used ffmpeg extensively for FOSDEM already
[11:39:13 CEST] <markvandenborre> I thought it might be a nice idea for me to say thank you here to all developers who might be around
[12:17:27 CEST] Action: mrelcee patches bhyve for audio
[13:42:31 CEST] <asturel> hi, i wanted to use delogo filter to mask hardcoded subtitle but the resolution is much worser quality video
[13:42:40 CEST] <asturel> even the size is half of the original
[13:42:54 CEST] <asturel> ffmpeg -i input -vf delogo=x=80:y=400:w=490:h=60 -c:a copy output
[13:49:26 CEST] <BtbN> that won't change the video resolution. But it will encode with default parameters, which are usually quite bad.
[13:50:05 CEST] <asturel> so how can i produce near the same quality video?:D
[13:50:27 CEST] <asturel> its an old xvid anime.. :D
[13:50:33 CEST] <asturel> should i recode with x264?
[16:39:10 CEST] <vans163> There seems to be huge problems with the NaCl decoder decoding avcc streams and other things
[16:39:15 CEST] <vans163> (pepper api)
[16:39:27 CEST] <vans163> seems an inbrowser solution might not be possible
[17:02:14 CEST] <iive> what?
[19:07:38 CEST] <mrelcee> is there a guide around for making a static compiled binary with external libraries?
[19:14:32 CEST] <DHE> assuming Unix, --extra-ldflags=-static    but you need .a versions of all libraries involved. system and external
[21:02:04 CEST] <wCPO> I'm trying to copy part of a VOB file, but the timestamp is somehow messed up in the VOB file.. It like it switch to a new chapter after 2 minute and then the timestamp suddenly goes to 26:xx:xx something..
[21:03:43 CEST] <wCPO> I'm trying to use ffmpeg to seek.. So I can copy 20 seconds.. This is my command right now: ffmpeg -ss 00:01:00 -i VTS_01_3.VOB -to 00:05:00  -c copy foo.mkv (ignore it is 4 minute I try to copy). but ffmpeg just crash..
[21:04:14 CEST] <wCPO> This is the output: http://sprunge.us/CcZR
[21:05:07 CEST] <durandal_1707> that's not crash
[21:05:25 CEST] <wCPO> durandal_1707, oh yes, wrong word ..
[21:05:33 CEST] <durandal_1707> try -fflags +genpts
[21:06:35 CEST] <wCPO> durandal_1707, it seems like it just stuck then.. or is ffmpeg reading the whole file?
[21:08:18 CEST] <durandal_1707> have you tried above?
[21:09:23 CEST] <wCPO> durandal_1707, yes, but it haven't finished yet.. Is it reading the whole file?
[21:10:27 CEST] <durandal_1707> it should be pretty fast
[21:11:16 CEST] <wCPO> durandal_1707, the VOB file is 1,1GB and ffmpeg is using 100% cpu, not sure..
[21:15:40 CEST] <wCPO> So I added -loglevel debug and it just stop writing anything to the terminal just after it started..
[22:45:44 CEST] <Sulli> Hi, not sure I'm in the right place.  I'm trying to covert from mkv to
[22:46:34 CEST] <Sulli> Hi, not sure I'm in the right place.  I'm trying to covert from mkv to mp4 and I understand this can be done with ffmpeg without any loss in quality by copying the video and audio streams without re-encoding.
[22:50:15 CEST] <c_14> yeeees?
[22:50:52 CEST] <JEEB> Sulli: if all the streams are supported in mp4, `ffmpeg -i input -map 0 -c copy out.mp4`
[22:51:09 CEST] <JEEB> -map 0 means "map all streams from the first (0th) input file"
[22:51:22 CEST] <JEEB> -c copy sets transcoding to "copy" which does what you'd think it does
[22:51:27 CEST] <c_14> aww, and here I was waiting for a question
[22:53:14 CEST] <Sulli> JEEB: Thanks, can this be done with all files in a folder?
[22:53:44 CEST] <JEEB> you'd have to script that so you grab a list and then call ffmpeg for all of them
[22:53:55 CEST] <JEEB> any scripting language is capable of it
[22:54:30 CEST] <Sulli> Oh okay, that explains why I was struggling to find it
[23:07:41 CEST] <Sulli> Thanks for the help.
[23:23:15 CEST] <kevr> sick, finally getting down to tracking down timestamps of frames properly
[23:23:23 CEST] <kevr> with your guys help <3 thanks so much
[00:00:00 CEST] --- Mon Sep 19 2016