[Ffmpeg-devel-irc] ffmpeg.log.20160710

burek burek021 at gmail.com
Mon Jul 11 02:05:01 CEST 2016


[03:00:22 CEST] <PlanC> is there a way to set the user permssions for the output file with ffmpeg?
[03:00:51 CEST] <PlanC> I'm running ffmpeg as a user and when I run stat on the output files they belong to root
[03:00:54 CEST] <PlanC> instead of the user
[03:01:14 CEST] <PlanC> so I have to run chown on the output files which sucks because I have to login to root to do it
[03:11:51 CEST] <DHE> what shouldn't be possible unless you set ffmpeg as setuid root (!!)
[03:16:03 CEST] <PlanC> DHE: any idea on how I can fix it?
[03:21:42 CEST] <DHE> PlanC: what do you see if you "ls -l ffmpeg"  (the path to your ffmpeg binary)
[03:21:51 CEST] <DHE> looking for "rws" permission
[03:39:28 CEST] <PlanC> -rwxr-xr-x 1 root root 25364952 Jul  7 18:39 /usr/local/bin/ffmpeg
[04:18:07 CEST] <william_> hi i am having trouble compiling ffmpeg on Mint using the official guide
[04:19:01 CEST] <william_> i am getting first errors during the configure process
[04:42:42 CEST] <william_> pkg_config errors
[11:36:16 CEST] <shoo> Hello! I know it seems like my Linux Mint 17.2 problem, but maybe someone will help me here! I am learning ffmpeg by tutorial, and getting "ffmpeg_sources/ffmpeg/libavutil/hwcontext_vaapi.c:915: undefined reference to `vaGetDisplayDRM'" compile error at my first app
[11:37:09 CEST] <shoo> My app only include <libavcodec/avcodec.h>, <libavformat/avformat.h>, <libswscale/swscale.h>, and then call av_register_all();
[12:30:38 CEST] <jkqxz> shoo:  If you want an immediate fix, adding "-lva-drm" at the end of your link line will probably fix it.  But, that should have been done by pkg-config - what libraries did pkg-config tell you to use?
[12:47:25 CEST] <shoo> Thanks jkqxz, it works now! I am second day with C and GCC, so I am kinda confused with linker, I use "gcc tutorial01.c -o tutorial01 $(pkg-config --cflags --libs libavcodec libavformat libswscale) -lX11 -lva-x11 -lva-drm -lva -lvdpau" string to compile my .c file
[12:48:11 CEST] <shoo> but when I use  $(pkg-config --cflags --libs libva) it only saing me to use "-lva" and nothing else
[12:51:11 CEST] <furq> shoo: pkg-config --libs libva-drm
[12:51:19 CEST] <furq> and libva-x11
[12:51:57 CEST] <ffmpegUser1122> hey guys. im trying to use get image sequence from url as following  $ ffmpeg -framerate 1/5 -i http://localhost:8080/ffmpeg/img%03d.png -c:v libx264 -vf "fps=25,format=yuv420p" out.mp4 im getting the following error [image2 @ 0x30dbd80] Could find no file with path 'http://localhost:8080/ffmpeg/img%03d.png' and index in the range 0-4 http://localhost:8080/ffmpeg/img%03d.png: No such file or directory what am i missing ? 10x :
[12:52:42 CEST] <furq> what gave you the impression image2 could load files over http
[12:53:05 CEST] <ffmpegUser1122> oh damn
[12:53:11 CEST] <ffmpegUser1122> isnt?
[12:53:23 CEST] <furq> i can't say i've ever tried, but i doubt it
[12:53:54 CEST] <ffmpegUser1122> well the funny thing is .. my server getting hits from the right file index
[12:54:38 CEST] <ffmpegUser1122> 2016/07/10 - 13:47:05 | 200 |     163.399µs | 127.0.0.1 |  | Lavf/57.41.100 |   GET     /ffmpeg/img001.png 2016/07/10 - 13:47:05 | 200 |       85.54µs | 127.0.0.1 |  | Lavf/57.41.100 |   GET     /ffmpeg/img002.png
[12:59:25 CEST] <shoo> Thanks a lot guys, now I compile my file with pkg-config and no errors!
[13:00:16 CEST] <furq> huh
[13:00:18 CEST] <furq> that actually works for me
[13:00:46 CEST] <ffmpegUser1122> can i see the CLI command
[13:01:57 CEST] <furq> http://vpaste.net/nm66D
[13:02:40 CEST] <furq> try running your command with -v debug
[13:03:04 CEST] <furq> be prepared for a million lines of output though
[13:05:27 CEST] <ffmpegUser1122> http://pastebin.com/4vPfEtCs
[13:06:23 CEST] <furq> wtf is going on with those paths
[13:07:10 CEST] <ffmpegUser1122> theres jumping .. idk why
[13:07:39 CEST] <ffmpegUser1122> but seems like its downloading the files
[13:10:20 CEST] <arpu> hello. is it possible to use timestamp or date in output file (runtime for livestream)
[13:12:45 CEST] <ffmpegUser1122> crazy thing is .. same url without the pattern works fine
[13:14:23 CEST] <furq> it works with 3.1.1 so i guess it's not a regression
[13:15:21 CEST] <furq> it jumps by 2^n and then jumps back to (2^n-1)+1 when it gets a 404
[13:16:21 CEST] <ffmpegUser1122> my server output was 200 for requests
[13:16:32 CEST] <furq> do you have an app which is dynamically generating these images or something
[13:16:38 CEST] <furq> maybe it's breaking because it's not getting a 404
[13:16:48 CEST] <furq> although it should really stop at 999 since you're using %03d
[13:16:51 CEST] <ffmpegUser1122> k ill try in a sec
[13:17:46 CEST] <furq> if it turns out to be that then you probably want to report it as a bug
[13:26:03 CEST] <ffmpegUser1122> http://pastebin.com/pm2SMD9v
[13:26:07 CEST] <ffmpegUser1122> no luck :(
[13:28:00 CEST] <furq> that's getting further than it was before
[13:29:00 CEST] <furq> set -s 320x240 before -i
[13:29:04 CEST] <furq> or whatever the image dimensions are
[13:29:24 CEST] <furq> for some reason i didn't need that with 2.8 but i did with 3.1
[13:30:39 CEST] <ffmpegUser1122> no influence  at all with the size flag
[13:32:37 CEST] <furq> [image2 @ 0x39e8d60] Could not find codec parameters for stream 0 (Video: png, 1 reference frame, none(pc)): unspecified size
[13:32:40 CEST] <furq> is it still giving that error
[13:35:29 CEST] <ffmpegUser1122> nope im getting another error now
[13:36:05 CEST] <ffmpegUser1122> http://pastebin.com/t4eBjneQ
[13:41:18 CEST] <ffmpegUser1122> ok i got the problem
[13:46:48 CEST] <ffmpegUser1122> ill sums all things up in few minutes
[14:04:58 CEST] <ffmpegUser1122> so here's how i understand the whole thing of http image2 seq with http and "-analyzeduration 0". ffmpeg will try to understand what is the range of the sequence by hitting the server with n^2 frame index until getting few 404 response in a row. after that 404 responses, ffmpeg will start hitting server with the starting image index by framerate and duration defs. now its ok ;)
[14:05:49 CEST] <furq> yeah it seems weird that it would go beyond 999 with %03d
[14:06:00 CEST] <furq> like i said, it might be worth reporting that
[14:10:58 CEST] <ffmpegUser1122> k ill report it ;)
[16:02:05 CEST] <fanchig> Hello people,
[16:02:06 CEST] <fanchig> got a question here, a noobie one really - but I can't figure out why the following script won't work:
[16:02:06 CEST] <fanchig> ffmpeg -i Elser.mkv -c:a:2 copy -ss 260 -t 3 Elser_new.mkv
[16:02:17 CEST] <fanchig> By "won't work", I mean the output file still keeps the 1st audio stream (AC3), while I want to get the 2nd only (DTS).
[16:02:38 CEST] <furq> -map 0:v -map 0:a:1
[16:03:02 CEST] <fanchig> i'll try that, thanks
[16:06:16 CEST] <JEEB> by default ffmpeg cli selects a single stream that it thinks is the "best" one (vague definition of "best")
[16:06:28 CEST] <JEEB> of each type that is
[16:06:43 CEST] <JEEB> you have to use map if you want to select specific tracks :)
[16:06:57 CEST] <JEEB> what furq noted selects all video tracks and the second audio track
[16:07:56 CEST] <fanchig> ok, I got that yes, I just didn't think I needed to use -map on this one
[16:07:59 CEST] <fanchig> still a beginner...
[16:08:08 CEST] <fanchig> thx for the clarification :)
[16:09:05 CEST] <fanchig> ok, it looks like I got the right channel now, that's a first victory.
[16:09:19 CEST] <fanchig> ...so thanks furq
[16:09:35 CEST] <fanchig> Yet, it has changed DTS into Ogg
[16:09:48 CEST] <fanchig> while I'd like to keep to just transcode the DTS as it is
[16:09:55 CEST] <JEEB> you mean remux :P
[16:09:58 CEST] <fanchig> yup
[16:10:04 CEST] <JEEB> and yes, never leave -c undefined for tracks
[16:10:24 CEST] <JEEB> by default it picks *something* according to the output container
[16:10:34 CEST] <JEEB> and re-encodes to that
[16:10:37 CEST] <JEEB> thus -c:a copy
[16:10:45 CEST] <JEEB> copies all selected audio tracks
[16:11:21 CEST] <JEEB> -c:a:2 would affect the third audio track you selected, which you probably don't have in your output :P
[16:11:26 CEST] <JEEB> (because you selected a single audio track)
[16:12:04 CEST] <fanchig> yeah, I thought video was actually the first stream (#0), hence 2
[16:12:37 CEST] <fanchig> I only have two audio tracks in my input
[16:12:57 CEST] <JEEB> it doesn't matter, -c applies to things after selection
[16:13:34 CEST] <JEEB> map first, which maps streams to output, and then for those you then set -c
[16:14:02 CEST] <JEEB> so if you pick a single video and audio track, you only have -c:a:0 and -c:v:0 which is why you might as well just do -c:a and -c:v
[16:14:39 CEST] <fanchig> ok, the latter I got it
[16:20:23 CEST] <fanchig> ...or did I?
[16:20:30 CEST] <fanchig> To me, it'd look like
[16:20:32 CEST] <fanchig> -map 0:a:1 -c:a:1 copy
[16:20:35 CEST] <fanchig> as for the audio.
[16:20:44 CEST] <fanchig> map first, then copy
[16:21:47 CEST] <fanchig> script now running with that..
[16:23:02 CEST] <JEEB> do you have two audio tracks in the output?
[16:23:13 CEST] <JEEB> -c after -i (for output) affects tracks you've selected!
[16:23:25 CEST] <JEEB> also it says whether it's copying or not in the terminal output :P
[16:28:22 CEST] <fanchig> I have one audio track in the output, which is what I'm after, and the correct stream
[16:28:47 CEST] <fanchig> just not the right codec (DTS)
[16:29:05 CEST] <furq> fanchig: -c:a copy
[16:29:14 CEST] <JEEB> -c:a:1 is the SECOND SELECTED (as in, that is in the output)
[16:29:15 CEST] <furq> there's no need to specify a stream if you only have one in the output
[16:29:36 CEST] <JEEB> not SECOND INPUT (unless you are specifying a decoder and doing it before -i)
[16:33:13 CEST] <fanchig> furq: thanks! Just dropped the :1 spec and DTS appeared
[16:33:57 CEST] <fanchig> Jeez, it's gonna take me some time to master the basics of this
[16:33:59 CEST] <JEEB> well yes, since you only had a single track there it didn't apply to any tracks (as I've been trying to note a couple of times 1 was the *second* audio track)
[16:34:02 CEST] <fanchig> but I got it on this one
[16:34:21 CEST] <JEEB> and as I noted before that if you only have a single track of a type just don't specify track numbers :)
[16:34:31 CEST] <fanchig> thanks to you both for your time JEEB and furq
[16:34:52 CEST] <fanchig> it makes sense indeed now, sorry 'bout that :p
[16:35:07 CEST] <furq> just hang out in this irc channel for months and you too can be a master
[16:35:47 CEST] <fanchig> Haha, well-noted, I might let it run then in the evenings and weekends
[16:36:22 CEST] <fanchig> really cool tool to play with once you get the concepts I guess
[16:36:26 CEST] <fanchig> already quite fun anyway
[16:36:37 CEST] <fanchig> Thanks again and greetings from France
[16:54:57 CEST] <Polochon_street> Hi ! I'm trying to parallelize some decoding program by opening several audio files at once, but I have the error « No URL Protocols are registered. Missing call to av_register_all()? » even if I indeed call av_register_all() each time. Is it a known problem, and am I doing something wrong ?
[16:57:06 CEST] <JEEB> what's your config.log from your build (please provide in a pastebin or similar, do not paste on the channel)
[16:58:27 CEST] <Polochon_street> well, the only ffmpeg output I have is the one I pasted above
[16:58:55 CEST] <Polochon_street> oh, I see, sorry, you want something else
[17:08:10 CEST] <Polochon_street> JEEB: here you are http://sprunge.us/bWdb
[17:10:35 CEST] <JEEB> ok, then you most probably are just using the API wrong or something
[17:10:47 CEST] <JEEB> I was expecting to see disable-everything and you just not having things enabled in your build
[17:11:37 CEST] <Polochon_street> okay. Is it a problem to use av_register_all() on different threads ?
[17:11:39 CEST] <JEEB> there could be bugs of course, but a lot of stuff would be broken if file protocol wasn't usable
[17:11:50 CEST] <JEEB> not sure :P
[17:12:08 CEST] <Polochon_street> no, you're obviously right but I'm really new to parallelizatio
[17:12:09 CEST] <Polochon_street> n
[17:12:41 CEST] <Polochon_street> all I'm doing is parallelizing a for(), and decode different files on different cores
[17:13:01 CEST] <JEEB> but yes, it could be global thing somewhere in lavf/lavc main state. not sure though
[17:13:11 CEST] <JEEB> haven't had a case where I had to do something like that
[17:14:31 CEST] <Polochon_street> too bad :/. Thanks anyway !
[18:58:25 CEST] <Jeena> Hi, I have two webcams which stream rtsp is it possible to use ffmped to join those streams to get one where the first is on the left and the other on the right?
[18:58:38 CEST] <Jeena> if so, what should I google for?
[18:59:58 CEST] <furq> -i rtsp://foo -i rtsp://bar -filter_complex vstack
[19:00:01 CEST] <furq> er
[19:00:03 CEST] <furq> hstack
[19:00:38 CEST] <Jeena> does that work with more than two streams too?
[19:01:22 CEST] <Jeena> ah that helps a lot while googling
[19:01:51 CEST] <Jeena> wow this is really awesome http://stackoverflow.com/questions/36268431/video-grid-with-vstack-and-hstack
[19:02:10 CEST] <Jeena> thanks a lot furq!
[21:46:32 CEST] <FishPencil> Looking to split a mp4 up. Is there an efficient way to view the video and find the frames I need for -ss with ffplay, or will I need another application to find the cut points?
[23:47:57 CEST] <jaggz> how can I save file space if I have 10 min of video but 60 of audio?
[00:00:00 CEST] --- Mon Jul 11 2016


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