[Ffmpeg-devel-irc] ffmpeg.log.20161120

burek burek021 at gmail.com
Mon Nov 21 03:05:01 EET 2016


[01:59:32 CET] <fling> What to use as a replacement for ffserver?
[01:59:53 CET] <fling> I need to capture what is sent to the server from a splitcam app
[02:01:07 CET] <tdr> fling, ffserver can be built if you built your ffmpeg from source too
[02:01:27 CET] <tdr> ffserver version 2.8.8 Copyright (c) 2000-2016 the FFmpeg developers
[02:01:27 CET] <tdr>   built with gcc 4.9.3 (Gentoo 4.9.3 p1.5, pie-0.6.4)
[02:02:24 CET] <fling> tdr: do I need ffserver for the task? Not sure how to capture the stream.
[02:04:40 CET] <tdr> ffserver your app for your cams already streams .. or whats its output options?
[02:07:50 CET] <fling> umm? :D
[02:07:55 CET] <tdr> if it can output to any number or normal framebworks ffserver could catch it, but so could alot of other things
[02:09:32 CET] <tdr> ffserver is primarily for streaming tho, so if you were piping through it something else would likely be "playing" the stream to dump it to disk, so at that point i'd just use ffmpeg attached to whatever framework your app outputs to, use ffmpeg directly to dump to disk etc
[02:23:12 CET] <fling> tdr: it cound output to several streaming services, right. The task is to capture on the server, not on the client.
[02:24:38 CET] <fling> tdr: so I need a software to run on the server.
[02:43:29 CET] <fling> tdr: it is like streaming but vice versa. The server app, not the client one.
[02:43:40 CET] <fling> So don't I need ffserver, right?
[05:04:13 CET] <tomed> why does so many dvd-videos has  black bar on all 4 sides
[05:42:28 CET] <tyng> what would be the most complete libpng reference encoder? ffmpeg, imagemagick, gimp.. or something else?
[05:43:21 CET] <tyng> libpng provides a lot of references http://libpng.org/pub/png/pngaped.html
[05:51:33 CET] <c_14> ffmpeg doesn't use libpng
[05:51:35 CET] <c_14> so
[05:51:37 CET] <c_14> eh
[05:51:55 CET] <tyng> libavcodec uses its own implementation?
[05:51:58 CET] <c_14> yes
[05:52:09 CET] <tyng> why? is it better?
[05:52:15 CET] <c_14> Because it can
[05:52:18 CET] <c_14> less dependencies
[05:52:37 CET] <c_14> better integration
[05:52:40 CET] <tyng> is it based on the iso reference?
[05:58:22 CET] <tyng> gimp isn't based on libpng either
[05:59:15 CET] <tyng> i am rather asking about png encoders based on the open standard
[06:00:30 CET] <c_14> I would presume the encoder/decoder are based on some version of the png specification though I don't know which it is
[06:03:59 CET] <c_14> Why are you looking for "the most complete png reference encoder"?
[06:04:32 CET] <c_14> You're probably better off figuring out what exactly you need your png encoder to accomplish and then testing a couple of the more common ones to see if they do what you want.
[06:16:09 CET] <tyng> i want to encode a lot of data for long term storage so i am looking into the available codecs
[07:22:00 CET] <fling> (security-camera)-->--[ffmpeg-on-a-streamer-box]-->--[?-on-a-storage-box]
[07:22:13 CET] <fling> 1. which app to run on the storage box? ^
[07:22:28 CET] <fling> 2. How to only save parts of videos containing movement?
[11:10:55 CET] <fling> How to put the current date to a file metadata?
[11:11:03 CET] <fling> Without using `date` (on windows)
[12:03:05 CET] <wouter> DHE: thanks (for your reply yesterday :)
[13:46:43 CET] <fling> seeking mostly not working if ffmpeg was wrongly killed while writing to the file. How to fix this?
[13:47:07 CET] <somaReverse> hello
[13:47:16 CET] <somaReverse> what's wrong with this option " -r 16 -c:v libx264 -preset ultrafast -crf 30 -c:a libvorbis "
[13:47:18 CET] <JEEB> fling: remux :P
[13:47:41 CET] <fling> JEEB: sure but is not there a magical option for encoding in something like a stream mode?
[13:48:11 CET] <fling> somaReverse: what is the error message?
[13:48:11 CET] <JEEB> that doesn't help for seeking
[13:48:21 CET] <JEEB> I mean, you write an index after the thing's done
[13:48:25 CET] <fling> JEEB: what does help then?
[13:48:27 CET] <fling> ahhh ok
[13:48:38 CET] <JEEB> if you kill shit in the middle then no index for you
[13:49:08 CET] <fling> it is running on windows and windows is rebooting killing everything the wrong way
[13:49:13 CET] <JEEB> the best you can get is isobmff with movie fragments I guess? which means that every GOP will be in its own little indexed thing and just the last one goes the way of the dodo :P
[13:49:42 CET] <fling> hmm hmmm
[13:49:47 CET] <kerio> mpegts?
[13:49:57 CET] <JEEB> mpeg-ts is only exact in seeking if you index it
[13:50:04 CET] <JEEB> if you are OK with "close enough"
[13:50:09 CET] <JEEB> then mpegts or nut would be OK
[13:50:16 CET] <JEEB> or matroska I guess :V
[13:50:23 CET] <fling> I'm writing to nut
[13:50:33 CET] <JEEB> and that's why you can play the file
[13:50:42 CET] <fling> Right.
[13:50:44 CET] <JEEB> seeking index isn't getting written so you're getting funkyness there
[13:51:00 CET] <fling> Right, rewind works but not ff
[13:51:19 CET] <JEEB> anyways, you can generally fix such stuff with a remux
[13:51:23 CET] <JEEB> -c copy and all that jazz
[13:51:27 CET] <fling> Sure! I know
[13:51:40 CET] <fling> But I want to make it playable out of the box&
[13:51:51 CET] <somaReverse> fling: I cannot get the error message
[13:51:52 CET] <fling> How to isobmff?
[13:51:59 CET] <fling> somaReverse: what is the issue then?
[13:52:00 CET] <somaReverse> it's inside a gui program
[13:52:06 CET] <somaReverse> it's not working
[13:52:14 CET] <fling> somaReverse: run it on the outsize
[13:52:19 CET] <fling> s/z/d/
[13:52:24 CET] <somaReverse> the script looks like this
[13:52:31 CET] <somaReverse>         if [[ -z $ffaudio ]]; then $encoder -f x11grab ${border} -s "$W"x"$H" -i $ffmpeg_display+$X,$Y $rect_encopts "${vid_path}/${filename}" &
[13:53:32 CET] <fling> JEEB: I cant find what it is :P
[13:54:01 CET] <JEEB> fling: -f mp4 -movflags empty_moov+frag_keyframe
[13:54:10 CET] <JEEB> ISOBMFF is the fancy name for what is colloquially called mp4
[13:54:16 CET] <JEEB> ISO Base Media File Format
[13:54:29 CET] <fling> So it is not useable for nut right?
[13:55:00 CET] <somaReverse> ah I get the output https://ptpb.pw/2kX3
[13:55:04 CET] <JEEB> well nut works better out of the box so it doesn't need that :P
[13:55:14 CET] <JEEB> but as you can see the seeking perf lacking an index sucks
[13:55:57 CET] <fling> somaReverse: and now we need the command :>
[13:56:17 CET] <fling> JEEB: don't I need to try mkv right?
[13:56:25 CET] <fling> I will probably leave this as is for a while&
[13:56:36 CET] <fling> I still need to figure out how to motion detect
[13:57:11 CET] <somaReverse> hmm
[13:57:19 CET] <somaReverse> how can I get the command
[13:57:29 CET] <fling> somaReverse: you have specifiend -i twice or you have a weird -map
[13:58:18 CET] <fling> somaReverse: try putting "set -x" before the funny part
[13:58:30 CET] <fling> if it is bash or something
[13:58:37 CET] <somaReverse> ok
[13:58:39 CET] <somaReverse> the command ffmpeg -f x11grab -show_region 1 -s 523x303 -i :0+266,232 -r 16 -c:v libx264 -preset ultrafast -crf 30 -c:a libvorbis /home/amos/Videos/Screencasts/vid-2016-11-20-205818.gif
[13:59:06 CET] <fling> JEEB: why is not there opus in nut btw? :P
[13:59:46 CET] <JEEB> nobody cared enough? do note that most people using nut in production only utilize it to pipe raw video/audio with timing information from one thing to another
[14:00:01 CET] <JEEB> I mean, as you can see it works for other stuff as well but yunno
[14:00:20 CET] <JEEB> you can add a thing about it if you want opus in nut for your use case :D
[14:00:32 CET] <fling> somaReverse: `ffmpeg -f x11grab -show_region 1 -s 523x303 -i :0+266,232 -r 16 /home/amos/Videos/Screencasts/vid-2016-11-20-205818.gif`
[14:00:43 CET] <fling> somaReverse: if you are writing to this gif
[14:01:11 CET] <somaReverse> so I need to remove " -c:v libx264 -preset ultrafast -crf 30 -c:a  " ?
[14:01:18 CET] <somaReverse> how can I make it fast then?
[14:01:26 CET] <fling> somaReverse: what are you doing?
[14:01:33 CET] <somaReverse> screencast
[14:01:44 CET] <fling> somaReverse: do you need gif?
[14:01:47 CET] <somaReverse> yes
[14:01:56 CET] <somaReverse> damn ios don't support webm
[14:02:10 CET] <fling> somaReverse: then I provided the proper command.
[14:02:16 CET] <somaReverse> thanks
[14:02:49 CET] <fling> yw
[14:03:58 CET] <fling> somaReverse: also try putting -framerate 16 before -i instead of using -r 16 after -i
[14:04:07 CET] <fling> somaReverse: it could speedup things
[14:04:43 CET] <fling> and maybe the same for -video_size
[14:05:33 CET] <fling> JEEB: "add a thing about it" ? Like add it to the muxer? :P
[14:06:12 CET] <JEEB> or a thing on the issue tracker so that someone else might add it
[14:08:04 CET] <fling> Which codec should I use for a slow fps screencast?
[14:08:09 CET] <somaReverse> fling: hmm
[14:08:14 CET] <fling> Like 1fps
[14:08:16 CET] <somaReverse> this gif size is so big
[14:08:24 CET] <somaReverse> how can I make it smaller
[14:08:29 CET] <fling> somaReverse: try using less fps
[14:08:48 CET] <somaReverse> -r 8?
[14:08:51 CET] <jj15> Ive released the Facebook Live Reactions script. Uses ffmpeg and PHP. Includes live shoutouts too. https://github.com/JamesTheHacker/Facebook-Live-Reactions
[14:09:51 CET] <fling> somaReverse: ffmpeg -f x11grab -show_region 1 -s 523x303 -framerate 1 -i :0+266,232 /tmp/test.gif
[14:13:33 CET] <somaReverse> fling: ok, gif is so not a choice now.
[14:18:22 CET] <fling> somaReverse: gif > ffv1 > mjpeg > x264
[14:18:57 CET] <fling> somaReverse: x264 looks good by the default (if you dont specify preset and crf) but it is 10 times smaller than the default gif
[14:21:01 CET] <fling> somaReverse: I'm now capturing with this -> ffmpeg -f x11grab -r 1/6 -s 1280x800 -i :0 -c ffv1 /tmp/screen.ffv1.mkv
[14:21:40 CET] <kerio> fling: why not ffvhuff
[14:21:43 CET] <kerio> it's not much bigger
[14:21:46 CET] <kerio> but it's MUCH faster
[14:22:16 CET] <somaReverse> fling: is mkv supported by all the browsers?
[14:23:53 CET] <fling> kerio: somaReverse: http://dpaste.com/2NZNE6F
[14:24:10 CET] <fling> somaReverse: use webm for browsers
[14:24:57 CET] <kerio> fling: that's like only a factor of two
[14:25:23 CET] <kerio> safari doesn't support webm
[14:25:40 CET] Action: fling is using wget.
[14:25:58 CET] <fling> lunchtime!
[14:26:03 CET] <somaReverse> fling: ok
[14:26:10 CET] <fling> somaReverse: good luck with your encoding, read the docs.
[14:26:15 CET] <somaReverse> could you give a webm capture options?
[14:27:34 CET] <schlurke1> hello together,i have got a question here  http://pastebin.com/QaaFezjN  maybe someone knows what I make wrong?
[14:27:35 CET] <fling> somaReverse: http://wiki.webmproject.org/ffmpeg
[14:27:56 CET] <fling> somaReverse: this one has examples https://trac.ffmpeg.org/wiki/Encode/VP8
[14:28:11 CET] <somaReverse> thanks
[14:28:38 CET] <fling> kerio: x264 produces really fancy image I will use it for the screencast
[14:28:50 CET] <fling> gif and mjpeg look really bead
[14:33:43 CET] <kerio> fling: i assumed the lossless capture was to then be processed
[14:38:24 CET] <fling> Can ffmpeg also capture subtitles from what I type?
[14:38:49 CET] <fling> kerio: turned out x264 looks good for me and it is fast.
[15:07:57 CET] <fling> JEEB: I have a video with an audio perfectly in sync but audio gets out of sync when I add a second video stream with the lower fps. How to fix this?
[15:08:05 CET] <fling> They are all live sources.
[15:20:50 CET] <fling> JEEB: fixed specifying fps for the first video codec
[15:20:52 CET] <fling> wtf :P
[15:24:27 CET] <fling> Does stream order mean? Should not I put all the video streams first then all the audio streams?
[15:30:54 CET] <fling> JEEB: fps applied also to the second stream because I have only one -c:v this is why it got fixed
[15:32:42 CET] <fling> ff does not work when playing the second stream :<
[15:56:32 CET] <Atlas69> hi
[15:58:30 CET] <Atlas69> Is their anyone able to help me?
[15:59:15 CET] <Atlas69> oh
[15:59:17 CET] <Atlas69> ok
[16:19:40 CET] <durandal_1707> Atlas69: ask
[16:19:53 CET] <Atlas69> Right...
[16:20:04 CET] Action: Atlas69 clears their throat
[16:20:40 CET] <Atlas69> So I'm trying to compile ffmpeg with the libopenmpt demuxer.
[16:21:21 CET] <Atlas69> I don't have libopenmpt on my system
[16:21:37 CET] <Atlas69> What do I do?
[16:22:06 CET] <durandal_1707> install libopenmpt
[16:22:20 CET] <Atlas69> ok, then?
[16:24:28 CET] <durandal_1707> configure ffmpeg with libopenmpt support
[16:24:39 CET] <Atlas69> how?
[16:24:52 CET] <Atlas69> I know I need o
[16:25:34 CET] <Atlas69> ...to do those two steps, but I don't know how I configure it.
[16:27:48 CET] <durandal_1707> ./configure --help from ffmpeg directory
[16:47:57 CET] <porton> How to check programmatically whether a given .mp4 file is mpeg or h.264?
[16:49:00 CET] <JEEB> mpeg is a group in ISO that has published a series of specifications :P
[16:49:29 CET] <bencoh> I suppose he meant "using ffmpeg/libav* api:" :)
[16:49:49 CET] <JEEB> he probably meant mpeg-1 or mpeg-2 or mpeg-4 part 2 I guess?
[16:49:56 CET] <JEEB> since H.264 aka AVC is MPEG-4 Part 10
[16:49:57 CET] <bencoh> most probably yeah :)
[16:50:02 CET] <porton> JEEB: I was ordered to convert all mpeg -> h.264 (but not to touch files which are already h.264)
[16:50:23 CET] <JEEB> porton: on a higher level the simplest way  to check is probably to parse ffprobe's json output
[16:50:30 CET] <JEEB> that way you don't have to go down and dirty
[16:50:36 CET] <JEEB> unless you want, of course
[16:51:30 CET] <furq> porton: ffprobe -v error -i foo.mp4 -select_streams v:0 -show_entries stream=codec_name:stream_tags=0:stream_disposition=0 -of default=nokey=1:noprint_wrappers=1
[16:52:47 CET] <porton> furq: tahnks
[17:00:00 CET] <markvandenborre> porton: mediaprobe might also be useful
[17:00:44 CET] <porton> markvandenborre: `apt-file search mediaprobe` outputs nothing on Debian
[17:00:51 CET] <furq> mediainfo
[17:01:08 CET] <furq> it's a good tool to have but it's not going to tell you the codec name any better than ffprobe can
[17:01:33 CET] <markvandenborre> furq: mediainfo indeed
[17:02:25 CET] <porton> markvandenborre: does it make any sense when the long command line by furq already works?
[17:11:00 CET] <walterav1984> question:ffmpeg/ffplay using firewire/1394 (h)dv input using "iec61883" with multiple camcorders doesn't work as expected single device work
[17:12:39 CET] <walterav1984> iec61883 has an option "dvguid" to select a specific firewire device when multiple active are connected,  this option is not working for me on ubuntu 16.04 amd64 with repo version and compilled ffmpeg of today
[17:17:55 CET] <walterav1984> To test multiple dv/hdv device capture on ubuntu 16.04 linux with  "dvgrab -noavc -guid 0x1234567etc -f raw cameraA" and  "dvgrab -noavc -guid 0x1234567etc -f raw cameraB" works fine at the same time on the same FW interface
[17:18:47 CET] <JEEB> better to post on the trac
[17:18:50 CET] <JEEB> as an issue
[17:19:18 CET] <walterav1984> The previous written example using dvgrab has a typo in it since the guid has to be different for a different camera
[17:19:40 CET] <walterav1984> <JEEB> don't know if its a issue or me specifying the wrong syntax
[17:20:11 CET] <JEEB> well you will get told but in this case I'd be surprised if someone utilizing firewire would be here at this point of time
[17:20:27 CET] <JEEB> just note that you're not sure if you're just DoingItWrong or if it's a boog
[17:22:20 CET] <walterav1984> <JEEB> true about people having old FW devices will probably not be here in the active IRC channel, I'll try filling a bug with the notion that it might be wrong syntax usage
[17:25:50 CET] <JEEB> sounds good
[17:31:02 CET] <hmir> Hi guys. I have a ffmpeg x.265 CRF question. In the ffmpeg x.265 documentation, it says X.265 CRF 28 is roughly equally X.264 CRF 23. So, would a X.265 CRF 30 be roughly equal to X.264 CRF 25?
[17:31:15 CET] <JEEB> no
[17:31:22 CET] <JEEB> their ranges are completely different
[17:31:35 CET] <JEEB> and instead of them being similar it should say that those are the default values (I think)
[17:31:48 CET] <JEEB> libx265 defaults to crf 28, and libx264 defaults to crf 23
[17:31:57 CET] <JEEB> and the encoders are completely different inside
[17:32:00 CET] <hmir> According to https://trac.ffmpeg.org/wiki/Encode/H.265 - "The CRF of 28 should visually correspond to libx264 video at CRF 23"
[17:32:03 CET] <JEEB> so the results *will* be different
[17:32:33 CET] <hmir> So, you're saying that webpage/information is wrong?
[17:34:12 CET] <JEEB> it's misleading if you expect anything from it
[17:34:20 CET] <JEEB> like you were just trying :P
[17:35:31 CET] <cerion> hi; how can I amek ffmpeg ignore chapter errors ?
[17:35:42 CET] <hmir> Alright, thanks.
[17:36:05 CET] <furq> cerion: -map_chapters -1
[17:36:14 CET] <cerion> furq: thanks
[17:36:31 CET] <furq> that'll disable chapters entirely, you'll need to edit the source file with an appropriate tool if you want to fix them
[17:36:37 CET] <walterav1984> Filling a track ticket/bug report thank you <JEEB> for suggestions.
[17:44:48 CET] <Jimmyon> Hello guys and girls! I am new to using ffmpeg command line, now i have ~60 video files (.mov) that i want to SHARPEN using the convolution filter. How would i go about that? Can someone guide me through it?
[17:47:51 CET] <DHE> you'll have to run a loop using your shell.
[17:48:36 CET] <durandal_1707> why to sharpen it?
[17:49:38 CET] <Jimmyon> Does the why even matter? :D I have a video im working on and some of the footage is just slightly blurry. I want to make those clips a little more crisp
[17:50:04 CET] <Jimmyon> and i dont even know what a shell is :D consider me to be about as new to the topic as can be
[17:50:19 CET] <Jimmyon> i know how to call a command line in a folder, thats about it
[18:05:53 CET] <SchrodingersScat> Jimmyon: so, linux?
[18:06:58 CET] <Jimmyon> im on Windows 10 schrodingersScat
[18:12:34 CET] <SchrodingersScat> with bash?
[18:13:38 CET] <Jimmyon> i dont even know what that means :(
[18:13:52 CET] <Jimmyon> i thought it might be relatively simple to write in a .bat? :S
[18:17:17 CET] <tab1293> is it possible to output what byte ffmpeg would start processing input at if the -ss flag is passed?
[18:18:46 CET] <BtbN> no.
[18:19:12 CET] <BtbN> Also, it probably start processing at the very beginning
[18:19:43 CET] <DHE> Jimmyon: the program providing your command-line is called your shell. that's why the newest version is called "powershell"
[18:22:00 CET] <tab1293> Does ffmpeg support any kind of remote resource seeking BtbN
[19:04:11 CET] <unkmar> I need the simpliest example of a functioning ffmpeg screen grab video to file.  something like ffmpeg -f x11grab test.flv
[19:05:04 CET] <unkmar> I'm so tired of rewriting the same script over and over because of tiny changes to ffmpeg and the differences with avconv.
[19:06:46 CET] <c_14> ffmpeg -f x11grab -i :0 out.mkv
[19:09:51 CET] <unkmar> both vlc and ffmpeg display 1 frame and then crash immediately on that example.
[19:09:57 CET] <unkmar> I mean, mplayer.
[19:10:08 CET] <c_14> When playing out.mkv?
[19:10:15 CET] <unkmar> yes.
[19:10:56 CET] <c_14> works for me...
[19:10:57 CET] <unkmar> Full disclosure: I'm using the much older ffmpeg from the debian 8 repos.
[19:10:59 CET] <c_14> What version of ffmpeg?
[19:11:22 CET] <unkmar>  3.2-2
[19:11:41 CET] <c_14> That's not that old
[19:11:50 CET] <unkmar> More percisely, ffmpeg version 3.2-2~bpo8+2 Copyright (c) 2000-2016 the FFmpeg developers
[19:13:20 CET] <unkmar> Just for testing, I switched my test.flv to test.mkv.  File extension made no differenct.  I didn't expect it would.
[19:13:40 CET] <c_14> Can you play this without crashing? https://dl.c-14.de/t/out.mkv
[19:15:06 CET] <unkmar> No!  mkv demux error: No tracks supported    cannot find any cluster, damaged file ?   [mp3 @ 0x7f23a0050a40] Header missing
[19:15:47 CET] <unkmar> and mplayer says.  No stream found to handle url https://dl.c-14.de/t/out.mkv
[19:16:29 CET] <c_14> Download with wget/curl and try again?
[19:16:57 CET] <c_14> But I'm going to guess that vlc/mplayer are linked against some old/broken version of libav*
[19:17:00 CET] <c_14> Do you have ffplay installed?
[19:17:12 CET] <c_14> (should be part of the ffmpeg package)
[19:17:32 CET] <unkmar> ffplay plays it fine.
[19:20:25 CET] <unkmar> Okay, at least I now have something to work *forward* from.
[19:20:46 CET] <c_14> Check the output of ldd `which mplayer`
[19:23:01 CET] <unkmar> broken version of libav.  I'm sure they are.  Since libav had to be removed in order to install ffmpeg according to debian.
[19:24:22 CET] <unkmar> I don't know what the output from "ldd `which mplayer`" meains.
[19:25:05 CET] <unkmar> I can tell you, it dumped a long list of what appears to be symlinks.
[19:25:14 CET] <c_14> There should be a line libavformat.so >= /path/to/libavformat.so
[19:25:20 CET] <c_14> Where is that path?
[19:25:29 CET] <c_14> And then check with dpkg to which package it belongs
[19:27:37 CET] <unkmar> I don't know how to check with dpkg.
[19:27:48 CET] <unkmar>  libavformat.so.56 => /usr/lib/x86_64-linux-gnu/libavformat.so.56 (0x00007f28f5dd8000)
[19:34:08 CET] <devsnd> Hi ffmpeggers! Does anybody know if it is valid in MP3 for the sample rate to change from frame to frame?
[19:35:27 CET] <SchrodingersScat> there's variable bitrate yes?
[19:35:41 CET] <SchrodingersScat> is, is that the same?
[19:35:43 CET] <furq> unkmar: dpkg -S /usr/lib/x86_64-linux-gnu/libavformat.so.56
[19:37:07 CET] <unkmar> furq: libavformat56:amd64: /usr/lib/x86_64-linux-gnu/libavformat.so.56
[19:37:22 CET] <furq> ffmpeg from jessie backports uses libavformat 57
[19:37:39 CET] <furq> backports are generally a bit wonky at sorting this sort of thing out
[19:38:51 CET] <furq> mplayer's libavformat is apparently from libav 11.8, which isn't that old
[19:39:19 CET] <unkmar> that would explain why I see both 56 and 57 installed.
[19:39:48 CET] <devsnd> SchrodingersScat, bitrate may vary in a MP3, yes. But I would like to know if it is valid that the sample rate changes, e.g. from 22050 to 44100 hz
[19:41:30 CET] Action: SchrodingersScat is in over his head
[19:48:31 CET] <devsnd> Well, even worse, may mp3s change between layers from frame to frame?
[19:49:20 CET] <devsnd> I've got this mp3 that plays on mplayer, but my own parser doesn't get it right :(
[19:59:43 CET] <unkmar> OMG, this is just NEVER going to work.  Why do I torture myself so?  I'll never get something that SHOULD be so simple to Freaking work.
[20:00:18 CET] <unkmar> And no!  I haven't spent about an hour at it.  It has been multiple days at no less than 3 hours each attempt to get this to work.
[20:04:33 CET] <bencoh> furq: err ... mplayer uses ffmpeg afaict (?)
[20:04:40 CET] <bencoh> (not libav)
[20:05:12 CET] <furq> it uses libavcodec/libavformat etc
[20:05:23 CET] <furq> on debian stable those are the ones from libav, on testing they're the ones from ffmpeg
[20:05:41 CET] <bencoh> ah you didn't been the builtin ffmpeg tree
[20:05:44 CET] <furq> stable backports has ffmpeg with the latest libs, but only packages from backports are linked against them
[20:05:58 CET] <furq> which evidently doesn't include mpv, mplayer or vlc
[20:07:04 CET] <furq> i would probably upgrade to testing, but all my debian boxes already run testing so that's easy for me to say
[20:18:36 CET] <unkmar> I'm not even fighting the vlc mplayer issue.
[20:19:33 CET] <unkmar> Its the rewrite of my script that originall used ffmpeg.  That I had to rewrite to use avconv.  That I'm having to rewrite to use ffmpeg, That is sending the first frame and then freezing and currently not supporting audio at all.
[20:20:18 CET] <unkmar> I have to work out all the various bug details that are preventing it from working in ANY player.  vlc, mplayer, and even ffplay.
[20:24:41 CET] <furq> pastebin the ffmpeg command that the script calls (or failing that, the script)
[20:46:29 CET] <Mockarutan> Hello ppl! Having some issued with AAC encoding in c++. I'm quite new at this stuff. Is this the place to ask? Most forums look really unactive.
[20:53:51 CET] <DHE> yes. first suggestion, there's demonstrations in /doc/examples/*.c you might want to check first
[20:56:04 CET] <Threads> anyway to add 100ms of blank audio to a mp3/aac/ac3 with ffmpeg ?
[20:56:12 CET] <unkmar> http://paste.debian.net/897049/
[20:56:14 CET] <Threads> want to add it at the start
[20:59:19 CET] <bsenftner> I am seeking advice on compiling ffmpeg. I am on Win10, and I can compile fine using the steps outlined herehttp://stackoverflow.com/questions/38634424/building-ffmpeg-for-visual-studio-development, but the dlls end with .dll.a <- is that wrong?
[20:59:47 CET] <BtbN> that's the implib.
[21:00:49 CET] <bsenftner> Will the av*.dll.a libs work as .dlls? there are .libs created, which I assume are for linking.
[21:02:43 CET] <BtbN> They are import libraries, not DLLs.
[21:03:11 CET] <furq> if you built with --enable-shared you should have dlls as well
[21:03:26 CET] <furq> i think the makefile puts them in bin/
[21:03:33 CET] <BtbN> if you have the implibs, you have the DLLs
[21:04:47 CET] <bsenftner> okay. Thanks. I thought the .libs were the import libraries. I've been looking in the parallel directories, and tried a search with everything.exe. I did use the --enable-shared. I'll try again, for the nth time...
[21:13:49 CET] <unkmar> So... Nothing input about the pastebin ?
[21:13:58 CET] <unkmar> *No input about the pastebin ?
[21:18:26 CET] <bsenftner> thanks for the help furq and BtbN. I found the dlls. Apparently, exerything.exe needs to be quit and relaunched to locate newly created files...
[21:20:37 CET] <furq> that sure doesn't sound right
[21:28:53 CET] <furq> unkmar: i can't see anything obvious but you probably want to remove -loglevel 0
[21:29:19 CET] <furq> i don't have a box with x11 i can test on
[21:35:28 CET] <unkmar> Soooo..... You are on a windows machine?
[21:38:26 CET] <unkmar> ffmpeg gives me: [flv @ 0x7f19f00008c0] video stream discovered after head already parsed
[21:38:30 CET] <unkmar> [flv @ 0x7f19f00008c0] Could not find codec parameters for stream 0 (Video: h264, none): unspecified size
[21:38:33 CET] <unkmar> Consider increasing the value for the 'analyzeduration' and 'probesize' options
[21:38:55 CET] <unkmar> And no video feed at all.
[21:39:21 CET] <unkmar> Sorry, I meant to say that is what ffplay tells me.
[21:39:57 CET] <unkmar> And that otherwise, ffmpeg appears to be running along smoothly.  Just nothing I have can play back the output.
[21:40:15 CET] <furq> do you get any warnings/errors from ffmpeg if you remove -loglevel 0
[21:40:36 CET] <unkmar> even without removing it.  I get:   Warning: data is not aligned! This can lead to a speedloss
[21:40:59 CET] <furq> that's a libswscale error iirc, i don't think that matters
[21:41:10 CET] <furq> s/error/warning/
[21:41:14 CET] <unkmar> And a big dump of Version numbers, and configuration settings.
[21:42:19 CET] <unkmar> So, No!  I don't really see anything that looks like an error or warning that might explain my problems.
[21:43:23 CET] <unkmar> Honestly, I can't tell if my stream is broken, my players are broken, or both.  Or is it my settings?  After all..  The strictest base version of the test does work with ffmpeg and ffplay.
[21:45:50 CET] <Mockarutan> I have looked though most examples I can find. Sort of stuck. The biggest issue I have now is that I need to generate some synthetic audio and place it in a AVFrame with AV_SAMPLE_FMT_FLTP formating. And think i'm going in circles now and messing up my code by the minute. The different data types and conversons in c++ is giving me a headace as a spoiled c# programmer :P So here is where I'm
[21:45:50 CET] <Mockarutan> at: http://pastebin.com/5Tvs19Am
[21:49:37 CET] <Mockarutan> 4 years of c# coding really makes you rusty in c++ :(
[22:16:59 CET] <MrMonkey31> do's and don'ts for making my videos pb smoother?  right now I change the framerate on home movies from 30 to 25 with -r 25.  hevc is the codec, crf is the mode
[22:18:26 CET] <Mavrik> Hmm, that's a strange thing to do.
[22:18:46 CET] <Mavrik> You'll lose some smoothness in any case, can't you avoid changing FPS?
[22:20:57 CET] <Mavrik> Is it interlaced?
[22:22:32 CET] <MrMonkey31> Mavrik: no, all my footage is new shiny and progressive.  well, I thought I would save on encode size and also, if I were to splice in another source here and there, that kind of thing
[22:22:50 CET] <Mavrik> Ahh, well you won't really save much on encode.
[22:22:58 CET] <Mavrik> Intraframe compression and all that.
[22:23:04 CET] <Mavrik> And you'll have severe juddering.
[22:23:14 CET] <Mavrik> I strongly suggest against it if you want your videos smooth :)
[22:23:45 CET] <Mavrik> There's a telecine filter in ffmpeg that can do pulldown, but it's meant for NTSC <=> PAL conversions
[22:23:46 CET] <MrMonkey31> understood.  I'm at a point in my understanding where it's really nothing's taken for granted but that's as I thought
[22:23:51 CET] <Mavrik> And even that's not perfect :/
[22:24:08 CET] <Mavrik> (And assumes interlaced content)
[22:24:59 CET] <MrMonkey31> my other q regarding encoded using x264 and x265 is, are the frames generally diplayed at as constant a rate as the playback platform can do?  or will it fudge intentionally?
[22:26:00 CET] <MrMonkey31> I have seen some content reporting a rate of say, 23.9760089, instead of 23.976000, and am wondering if that's all bubkiss or should I take note of it
[22:26:38 CET] <MrMonkey31> tho I guess knoiwing that isn't hugely important for me
[22:27:55 CET] <Mavrik> Umm, thing is, H.264 and H.265 aren't formats that demand (or have) constant framerate
[22:28:17 CET] <Mavrik> Every frame just has a timestamp on it when it needs to be displayed and that's it.
[22:28:36 CET] <Mavrik> That's why you sometimes get those non accurate calculations when tools try to calculate framerate
[22:29:11 CET] <Mavrik> So the devices are going to display the frame when it needs to be displayed, not when set framerate demands it.
[22:29:16 CET] <Mavrik> If you get what I mean O.o
[22:29:30 CET] <MrMonkey31> oh I getcha bud.  thanx!
[22:30:11 CET] <Mavrik> Phones for example don't record in constant framerate :)
[22:30:53 CET] <MrMonkey31> I so getcha I'm gonna rwd myself wit ha cookie.  yeah I had gathered as much from the otherwise meaningless (to me) documentation, and also from having had real unexplained problems when splicing
[22:32:11 CET] <MrMonkey31> I have worked around the latter with the parameter force_key_frames 0, iirc in addition to the trim video filter
[22:33:32 CET] <MrMonkey31> ...and that's my ffmpeg story, folks!
[22:34:24 CET] <furq> MrMonkey31: you can't accurately represent 23.976 in a double anyway, since the actual value is 23.976(023976)...
[22:41:12 CET] <MrMonkey31> eh well, there goes the neighborhood!
[22:41:34 CET] <kerio> furq: surely that should be 23.(976023)
[22:43:12 CET] <furq> that would have been better wouldn't it
[22:48:19 CET] <MrMonkey31> one concept I don't quite understand is timestamps in audio.  it falls apart right away, for me.  but the main concern is, when I do choose to change fr's, are there any extra steps which may be *required* to avoid desynching the audio?
[22:51:57 CET] <bencoh> why would it fall apart?
[22:52:51 CET] <bencoh> well, sure, if you consider that your stream is just one big chunk of audio meant to be played with no interruption, then .... it kinda defeats the purpose of timestamps
[22:52:57 CET] <furq> if you're changing framerate with -r or -vf fps then no
[22:53:23 CET] <furq> if you're changing it in some way that changes the duration of the video stream then sure
[22:53:42 CET] <bencoh> but then what about live streams and/or packet loss or interruptions, or whatever
[22:54:19 CET] <furq> if you go from 30fps to 25fps then some video frames may be a few ms out of sync with the audio but not enough that you'd notice
[22:56:14 CET] <MrMonkey31> oh so no worries, in other words!  well, only cause it seems like the playback end ought to... but I hadn't even considered streaming.  I guess I presumed it would be no different than just playing back a file locally
[22:58:26 CET] <MrMonkey31> I was in fact considering a change in the overall length, but one that might not be noticed till it compounds over the course of hours
[22:58:48 CET] <MrMonkey31> as I've said: can't take anything for granted!
[23:09:25 CET] <MrMonkey31> off I go!
[23:26:18 CET] <ago> Hello all.
[23:27:03 CET] <ago> while "ffmpeg -i $FILE -f null -" returns [NULL @ 0x61b00001ea80] Requested output format 'null' is not a suitable output format, what I need to enable to make it work?
[23:27:55 CET] <sfan5> works fine here with "ffmpeg-git r82260.0e66dcd-1"
[23:29:04 CET] <furq> ago: pastebin the full command line and output
[23:29:36 CET] <furq> i'm guessing it's either an old version or a build with --disable-everything
[23:30:51 CET] <ago> furq: the build has --disable-everything (for a reason). So I don't know what to enable.
[23:31:10 CET] <furq> --enable-muxer=null
[23:31:59 CET] <ago> that's what I'm trying now..
[23:35:14 CET] <ago> furq: it worked, thx
[23:59:36 CET] <DHE> ago: --disable-everything is not recommended for new users. a lot of things will mysteriously break. for example you might not be able to resize frames now if you didn't correct for that.
[00:00:00 CET] --- Mon Nov 21 2016


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