[Ffmpeg-devel-irc] ffmpeg.log.20180920

[burek]

[00:26:12 CEST] <nicolas17> Stadtpirat: so if you want it exact you have to re-encode
[00:27:18 CEST] <nicolas17> but I wonder... when cutting like that, couldn't ffmpeg re-encode partial audio packets or video GOPs at the beginning and end, and copy the rest?
[00:28:52 CEST] <JEEB> it could
[00:29:15 CEST] <JEEB> that's not straightforward and requires various additional logic
[00:29:27 CEST] <nicolas17> yeah totally
[00:30:21 CEST] <nicolas17> needs to ensure it's the same profile for example... wouldn't want to -vcodec copy h264-baseline stuff and transcode a GOP into h264-high at the end :P
[00:30:44 CEST] <nicolas17> and a dozen other things
[00:33:50 CEST] <Stadtpirat> nicolas17, I don't want to, but good to know. Thanks.
[00:35:55 CEST] <allohol> kepstin: fyi, i could solve the 'mystery' about that crop which should work ... stupid me had another '-vf' later on in that cmdline *fp*
[00:58:26 CEST] <rmbeer> hello...
[00:58:36 CEST] <rmbeer> how to concatenate two videos??...
[01:03:41 CEST] <BtbN> https://www.google.com/search?q=ffmpeg+concatenate+videos first hit...
[01:07:27 CEST] <rmbeer> BtbN, *FACEPALM* .... someone wants to help me in a decent way?...
[01:08:22 CEST] <BtbN> That literally links you to the wiki article that explains in detail how to concat videos, what else do you want?
[01:09:02 CEST] <nicolas17> rmbeer: did you try searching yourself? did you find the wiki article? did the examples there not work? why did they not work?
[01:11:39 CEST] <rmbeer> nicolas17, why appear this: Unsafe file name './p1.mkv'
[01:12:59 CEST] <rmbeer> i use this: -f concat -i [TXT con lista de nombre de archivos] -c copy
[01:14:39 CEST] <rmbeer> and use this, but appear bad cut in the video: 'ffmpeg -i "concat:p1.mkv|p2.mkv" p3.mkv'
[01:15:06 CEST] <nicolas17> strange... try without the ./
[01:15:53 CEST] <rmbeer> nicolas17, use only the file, late with './', and late with complete path, and late with 'file '/path/of/file''
[01:16:37 CEST] <nicolas17> file p1.mkv
[01:16:55 CEST] <nicolas17> that doesn't work? hm
[01:17:58 CEST] <nicolas17> "A file path is considered safe if it does not contain a protocol specification and is relative and all components only contain characters from the portable character set (letters, digits, period, underscore and hyphen) and have no period at the beginning of a component."
[01:18:06 CEST] <nicolas17> documentation of the 'concat' demuxer ^
[01:27:56 CEST] <rmbeer_> nicolas17, thanks... now work...
[08:23:18 CEST] <ilushka4> hey guys, I'm trying to run a rtsp stream from university's server. I always have an authentication problem, although I have the right credentials. Here is the log: https://paste.ee/p/CigFa
[09:49:19 CEST] <vascom> Hi all
[09:53:03 CEST] <Nacht> Hmm. FFMPEG doesn't have HEIF support yet ?
[09:53:29 CEST] <JEEB> because HEIF is a mess
[09:53:49 CEST] <Nacht> In what way ?
[09:53:50 CEST] <JEEB> it's an image in parts, yet the parts themselves are "frames" of a video in mp4
[09:54:05 CEST] <JEEB> even though HEVC has its own feature to have blocks of image coded separately
[09:54:16 CEST] <Nacht> Yeah I noticed as much. Found a comparison with GIF, yet the HEIF example was a canvas
[09:54:30 CEST] <JEEB> that's because nobody has a HEVC decoder :P
[09:54:33 CEST] <JEEB> so the decoding is done in JS
[13:20:26 CEST] <ariyasu> when scaling with this
[13:20:31 CEST] <ariyasu> -sws_flags spline -vf crop=1914:1080:2:0,scale=1280:-4,setsar=1/1
[13:20:54 CEST] <ariyasu> is there any way to set a maximum value for the output height?
[13:21:03 CEST] <ariyasu> so it does not exceed 720 pixels?
[13:21:34 CEST] <ariyasu> at the moment when cropping 2 from the left and 4 from the right, and trying to scale with the above code
[13:21:48 CEST] <ariyasu> the output becomes 1280x724 instead of 1280x720
[14:01:07 CEST] <gnealz> hi all, i built ffmpeg from source but unsure which flags to use, so atm videos (vimeo, yt) don't play
[14:03:08 CEST] <gnealz> https://pastebin.com/PVnzKLJj
[14:31:34 CEST] <kepstin> gnealz: what do you mean by "don't play"? ffmpeg isn't a player. By default it has a pretty complete set of builtin decoders enabled, too.
[14:34:34 CEST] <gnealz> videos just have a looping icon over them, not a network issue. only change on my system was building ffmpeg
[14:35:37 CEST] <gnealz> i found a guide to build it https://trac.ffmpeg.org/wiki/CompilationGuide/Centos so i'll follow this and hopefully will have workable binaries
[14:45:43 CEST] <kepstin> videos have a looping icon where? in the web browser? (firefox?)
[14:45:50 CEST] <kepstin> if so, building ffmpeg isn't gonna fix that
[14:50:53 CEST] <kepstin> other folks have already done the work required for media playback on centos/fedora - you can install a 3rd party repo and install the appropriate gstreamer plugins (which do use ffmpeg internally) and firefox will pick those up
[14:54:43 CEST] <kwizart> kepstin, firefox doesn't use gstreamer at all
[14:55:38 CEST] <kwizart> at least, last I've checked they use wrapper to dlopen ffmpeg libraries
[14:55:58 CEST] <kepstin> hmm. that must have changed, last I check was a while ago
[14:56:12 CEST] <kepstin> that said, centos is so old it might still have a firefox that uses gstreamer :)
[14:57:07 CEST] <kepstin> i wonder how they deal with changes with ffmpeg abi.
[14:57:28 CEST] <gnealz> i am running openSUSE
[14:58:18 CEST] <gnealz> and yea firefox, looping circle
[14:58:42 CEST] <gnealz> chromium too
[14:58:54 CEST] <kepstin> gnealz: first just check https://www.youtube.com/html5
[14:59:26 CEST] <kepstin> youtube should be serving up videos in vp8/9 for people without h264, so video playback being broken completely probably doesn't indicate a codec problem
[15:00:14 CEST] <kepstin> if you do want to try building an ffmpeg to see if it helps, you need to make sure to enable shared libraries, and ensure they're installed to a location in your system library load path.
[15:00:30 CEST] <gnealz> https://i.imgur.com/7UXGeJU.png
[15:01:03 CEST] <gnealz> H.264 and MSE & H.264 no support
[15:01:34 CEST] <kepstin> right, but vp9 and vp8 should be working fine :/
[15:03:10 CEST] <gnealz> oh there we go i disabled noscript entirely and it's playing in yt
[15:05:29 CEST] <gnealz> is H.264 no support likely an issue with ffmpeg? cause i can't think what else it would be, and considering that's the only thing i've changed on the system before noticing videos weren't playing
[16:11:02 CEST] <kepstin> gnealz: several linux distributions ship with h264 decoder (among other things) disabled due to patent licensing concerns.
[16:14:08 CEST] <gnealz> oh.... well ffmpeg finished building...not sure which path to put it in
[16:24:52 CEST] <gnealz> i just installed it from a repo... i'll reboot and see if that enables it
[16:39:39 CEST] <gnealz_> vimeo now plays on chromium and ff =] and yt/html5 says firefox has h.264. ty for help
[17:57:03 CEST] <lays147> For people that were helping me yestarday, apparently the flag cgop was supressing the -g option, making the gop value resulting on the value that I didnt want. we removed that and the video is now with the gop value that we desire =D
[17:59:32 CEST] <iive> cgop is closed gop, isn't it? if so, then it is a real bug that should be filled in a tracker.
[18:01:15 CEST] <lays147> iive: from the docs: cgop Use closed gop.
[18:03:50 CEST] <lays147> I was trying to process a video, and idk why I removed the -g param along the way of my tests. but then a coworker added again, and removed the cgop flag, and so our output was the valid one that we needed, so I tested again with and without cgop, and the behavior described above was what happened.
[18:06:53 CEST] <lays147> with the cgop flag the gop was GOP : M=3, N=13 and without the flag is GOP : M=3, N=15
[18:08:36 CEST] <lays147> the command line -> https://paste.kde.org/ptttwxg31
[18:30:40 CEST] <linuxmaster> Did anyone try to stream rtp? How to activate right ptime parameter?
[18:49:45 CEST] <lavalike> hello, can I use ffmpeg to grab an m3u8 stream, re-encode it at a lower resolution & bitrate, and serve it again?
[18:56:34 CEST] <johnnny22> having fun trying to resolve an alsa xrun issue :(
[18:58:09 CEST] <johnnny22> i'm getting an xrun after about 10 hours or so of recording an alsa loopback. I'm considering trying to raise the alsa loopback device's buffer & period sizes
[18:58:28 CEST] <johnnny22> anyone got other ideas of things to try ?
[20:06:01 CEST] <RavenWorks> Is there a way to let FFMPEG decide what output file suffix to use, when using 'copy'?
[20:06:06 CEST] <RavenWorks> i.e. if I want to do something like:
[20:06:11 CEST] <RavenWorks> ffmpeg -i %1 -vn -acodec copy outputfile
[20:06:53 CEST] <RavenWorks> I know I can look up what suffix to use manually with ffprobe, but I'd like to not have to bother :)
[20:07:13 CEST] <ChocolateArmpits> RavenWorks, suffix to what?
[20:07:19 CEST] <RavenWorks> the output file
[20:07:33 CEST] <ChocolateArmpits> you mean file extension?
[20:07:36 CEST] <Pennth> Trying to build with libvpx and I keep getting "ERROR: libvpx decoder version must be >=1.4.0" even after re-pulling git and rebuilding vpx.
[20:07:37 CEST] <RavenWorks> yes
[20:07:42 CEST] <ChocolateArmpits> RavenWorks, in a batch file?
[20:07:55 CEST] <RavenWorks> if possible
[20:10:59 CEST] <kepstin> Pennth: the configure script probably isn't picking up the correct libvpx. You may need to set PKG_CONFIG_PATH to the location for the pkg-config file for your newly built libvpx.
[20:13:08 CEST] <Pennth> kepstin, I tried that a couple times. I'm thinking now that I failed by building it beside ffmpeg in /usr/local/src rather than in a subdirectory
[20:13:28 CEST] <kepstin> Pennth: did you actually *install* libvpx somewhere?
[20:13:51 CEST] <ChocolateArmpits> RavenWorks, do you have a target format?
[20:14:21 CEST] <RavenWorks> the target format is whatever happens to be inside the file -- I'm specifically attempting to just copy what's there
[20:14:54 CEST] <ChocolateArmpits> RavenWorks, so if the format of the audio stream is aac, you expect it to be wrapped in either aac or m4a?
[20:15:02 CEST] <RavenWorks> Yes
[20:15:24 CEST] <Pennth> Yes, I ran 'make install'
[20:16:17 CEST] <kepstin> Pennth: and you had the PKG_CONFIG_PATH env variable set to the directory containing the libvpx.pc file for your newly installed libvpx when running ffmpeg's configure?
[20:16:56 CEST] <Pennth> there/s no libvpx.pc, just vpx.pc, but yes. Here's my command line:
[20:17:11 CEST] <Pennth> PKG_CONFIG_PATH=/usr/local/src/ffmpeg_build/pkgconfig/ ./configure --prefix=/usr/local --libdir=/usr/local/lib64 --shlibdir=/usr/local/lib64 --mandir=/usr/local/share/man --incdir=/usr/local/src/ffmpeg_build/include/ --pkg-config=/usr/bin/pkg-config --disable-avisynth --enable-libspeex --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-gpl --enable-nonfree --enable-pic --enable-postproc --enable-libvpx
[20:17:11 CEST] <Pennth> --enable-pthreads --enable-shared --enable-swscale --enable-vdpau --enable-version3
[20:18:01 CEST] <kepstin> Pennth: ok, what does `PKG_CONFIG_PATH=/usr/local/src/ffmpeg_build/pkgconfig pkg-config --modversion vpx` print?
[20:18:51 CEST] <ChocolateArmpits> RavenWorks, well this is pretty tricky because common output for specific codecs doesn't list formats that they can be wrapped in. That information is shown only through muxers and demuxers
[20:19:32 CEST] <Pennth> ah, doh! left out a path element. Should be PKG_CONFIG_PATH=/usr/local/src/ffmpeg_build/lib/pkgconfig
[20:19:54 CEST] <RavenWorks> yeah; it seems like ffmpeg is capable of telling me when a format I've chosen CAN'T be used with 'copy', but I haven't found any way to get it to say which ones WOULD work, other than lots of googling or trial and error
[20:20:26 CEST] <kepstin> RavenWorks: the library api doesn't provide any way to check that. you can only try to mux a codec into a container, and see if you get an error :/
[20:20:43 CEST] <Pennth> Nope, actually that still failed with the new path even though pkg-config --modversion vpx returns 1.7.0
[20:20:45 CEST] <kepstin> (well, there *is* a function to check, but most containers don't implement it)
[20:21:06 CEST] <ChocolateArmpits> RavenWorks, could you maybe make a list of input audio stream format and expected output?
[20:22:18 CEST] <RavenWorks> that's basically what I'm doing for now, as there's only a couple of different cases I'm doing this with, but it just seemed like wasted effort when it seemed like something there must be some way for the program to indicate
[20:22:20 CEST] <RavenWorks> but I guess not!
[20:22:49 CEST] <ChocolateArmpits> as far ffmpeg is concerned that would be ass backwards
[20:23:29 CEST] <RavenWorks> I guess another question is: does anyone know a good tool that's actually designed for demuxing files, then
[20:23:41 CEST] <RavenWorks> maybe I shouldn't be using ffmpeg to attempt this
[20:23:41 CEST] <ChocolateArmpits> ffmpeg?
[20:24:02 CEST] <ChocolateArmpits> If there's anything that handles so many formats, it'll have ffmpeg somewhere in there
[20:24:08 CEST] <kepstin> if your input is mkv specifically, mkvtoolnix has some stuff for that.
[20:24:20 CEST] <RavenWorks> sometimes it's mkv, sometimes it's mp4
[20:24:28 CEST] <RavenWorks> sometimes it's random things I'm not familiar with
[20:24:45 CEST] <RavenWorks> I just figured there must be some simple approach I was overlooking, but maybe not
[20:26:52 CEST] <kepstin> RavenWorks: I really can't think of any better way than having a list of "for codec X, the preferred standalone container is Y", and then have a few fallback containers (mkv or nut or something.?) to try for stuff not on that list.
[20:28:22 CEST] <RavenWorks> ah well! Thanks anyway, was worth a shot
[20:28:49 CEST] <kepstin> you have to be careful, because e.g. demuxing h264 then writing it in "raw" format loses timestamps and can drop some important metadata, for example.
[20:29:45 CEST] <RavenWorks> all the more reason I was hoping for a clear recommendation from the program!
[20:32:08 CEST] <kepstin> RavenWorks: a (usually) safe option is to output each stream into a separate file of the same format that the input was in ;)
[20:33:09 CEST] <RavenWorks> oh, hmm...! Would most audio players support audio alone in a container format like that?
[20:34:04 CEST] <RavenWorks> I guess it's worth looking into :) I'll keep it in mind, thanks!
[20:36:57 CEST] <Pennth> kepstin, any more advice? Or do I have to nuke it from orbit and start over? vpx is the only thing that's failing
[20:46:57 CEST] <kepstin> Pennth: does `PKG_CONFIG_PATH=... pkg-config --cflags --libs vpx` include the correct include and library paths?
[20:47:38 CEST] <kepstin> Pennth: also, there might be some info in the ffbuild/config.log
[20:48:49 CEST] <Pennth> looks good; -I/usr/local/src/ffmpeg_build/include  -L/usr/local/src/ffmpeg_build/lib -lvpx -lm
[20:51:22 CEST] <Pennth> Is there a preferred paste site for this channel?
[20:54:15 CEST] <Pennth> Actually now I get a make errror from x264 not being compiles with fPIC, so I'm going to make distcclean everything and start over :(
[00:00:00 CEST] --- Fri Sep 21 2018