[Ffmpeg-devel-irc] ffmpeg.log.20190712

burek burek021 at gmail.com
Sat Jul 13 03:05:02 EEST 2019


[00:00:12 CEST] <JEEB> that will give you like 90% of all decoders and other stuff like that
[00:00:23 CEST] <JEEB> you will get a nice list of enabled modules at the end of configure
[00:00:28 CEST] <JEEB> when it finishes configuring your build
[00:02:20 CEST] <steve___> This is an Abbott and Costello routine, except it's not funny (although it's getting close)
[00:04:02 CEST] <Thomas_J> You are right. What I am doing now is using a list of directives that I went through a week ago on things that I may possibly need in the future so I would not have to go through this again. There are a couple of thiings that I have already extablished that I need.
[00:04:23 CEST] <JEEB> aom? on an rpi3?
[00:04:37 CEST] <kepstin> speed measured in frames per week, lol :)
[00:04:39 CEST] <JEEB> you are not going to be decoding or encoding AV1 on your rpi
[00:04:58 CEST] <JEEB> and aom is not going to be in your repos
[00:05:55 CEST] <Thomas_J> I have already streamed a video to Facebook without glitches from my rpi.
[00:06:47 CEST] <kepstin> if you use the hardware encoder, that's quite reasonable do to. with appropriate settings, you can probably even manage x264 with sufficiently fast settings.
[00:06:52 CEST] <kepstin> not possible with av1.
[00:07:13 CEST] <JEEB> stream copy will also work fine, too
[00:07:19 CEST] <Thomas_J> And as I say, if things seem to bog down once I get the whole thing running, I will move it to a Rock Pi 4B
[00:07:53 CEST] <JEEB> ok, if you really want all that enabled, feel free
[00:09:45 CEST] <Thomas_J> No, you are right. I will flush out all that is not needed to do rtsp in, alsa in, needed filtering, and gnutls
[00:10:27 CEST] <Thomas_J> I am troubleshootng things that I don't even need.
[00:11:57 CEST] <Thomas_J> Should I build static?
[00:15:14 CEST] <kepstin> no point if you're running on the same box you're building on, it can make things more complex
[00:15:30 CEST] <kepstin> just use the defaults (don't specify any related ffmpeg configure options)
[00:19:58 CEST] <JEEB> static is default anyways
[00:20:50 CEST] <DHE> static means one of two things: the libraries are built as .a files instead of .so files - I like this best, but doesn't do well when building intermediary libraries using ffmpeg. or static means the executable is static, which is a tougher undertaking.
[00:20:55 CEST] <DHE> --enable-static means the former
[00:25:17 CEST] <Thomas_J> I've stripped the directives down to nill but pkg-config isn't finding anything.
[00:25:40 CEST] <Thomas_J> It now can't find libtls.
[00:31:38 CEST] <Thomas_J> What does "pkg-config --exists --print-errors libtls" mean? Everything that can't be found has print-errors???
[00:32:44 CEST] <JEEB> libtls != gnutls
[00:35:23 CEST] <Thomas_J> They are all starting to blend together in my eyes. I have l--enable libtls followed by --enable-gnutls. Duhh
[00:56:00 CEST] <Thomas_J> make is running right now and it is taking forever. I am going to dinner. So thanks all for your help. Tomorrow, I will be working with a brand new build.
[02:35:45 CEST] <BenMcLean> Hey guys. I need some help. I'm trying to make a simple Windows batch file which will edit the metadata in a video file designating that it is a 3D SBS video for purposes of YouTube and stereoscopic 3D VR video players that support it
[02:36:09 CEST] <BenMcLean> Now its my understanding that if you just want to edit metadata, then you shouldn't need to re-encode, it should just be an immediate change
[02:36:30 CEST] <BenMcLean> but when I run my command, it seems to be re-encoding anyway
[02:36:46 CEST] <BenMcLean> here is the command: ffmpeg -i %1 -c:v copy -c:a copy -c:s copy -c:d copy -c:t copy -metadata:s:v:0 stereo_mode=1 "%~n13D.%~x1"
[02:37:18 CEST] <BenMcLean> that should just copy everything, not re-encode right?
[02:37:41 CEST] <BenMcLean> the idea is to put that in a batch file, and then drag+drop the video file onto the batch file
[02:38:28 CEST] <BenMcLean> Is my idea sound in principle? or am I just way off base here about how any of this works?
[02:39:01 CEST] <BenMcLean> i know it has the right input file name and output file name at least
[02:40:31 CEST] <BenMcLean> oh wait, no it wasn't quite right. need to remove the extra dot at the end
[02:42:08 CEST] <BenMcLean> oh I think the correct command was ffmpeg -i %1 -metadata:s:v:0 stereo_mode=1 -codec copy "%~n13D%~x1"
[02:43:18 CEST] <MarkB2> I'm looking for a tool that will allow me to find rectangle size and top-left corner of an image so that (sorry) I can stop guessing with ffmpeg's crop option.
[02:44:19 CEST] <MarkB2> Might anyone have seen such a thing?
[02:53:53 CEST] <MarkB2> Ah.  Thank you.  Good idea.
[02:53:56 CEST] <MarkB2> Cheers.
[02:59:00 CEST] <nine_milli> blb_
[03:12:29 CEST] <tesseractcat> Hello, let's say I have a few hundred thousand image (PNG) files representing frames for a video. What's the fastest way to convert it to a video (i don't care about format as long as it's fast)
[03:22:33 CEST] <DHE> depending on the filenames.... ffmpeg -f image2 -pattern_type glob -i "*.png" -c libx264 -preset faster -crf 23 output.mp4
[03:22:52 CEST] <DHE> assuming "*.png" naturally orders the images correctly
[03:23:12 CEST] <tesseractcat> filenames are like output_%04d
[03:23:33 CEST] <DHE> that should be fine...
[03:23:39 CEST] <DHE> make sure to put quotes around "*.png"
[03:23:46 CEST] <tesseractcat> ok
[03:23:49 CEST] <tesseractcat> what does crf 23 do
[03:24:07 CEST] <DHE> H264 quality parameter. lower numbers are higher quality but bigger filesize
[03:24:15 CEST] <DHE> 23 seems to be a good sweet spot to start with. tune up/down as needed
[03:24:27 CEST] <tesseractcat> i see
[03:24:36 CEST] <tesseractcat> thanks
[03:25:21 CEST] <DHE> you said speed matters. "faster" can also become "veryfast" or "superfast" if speed really really matters, but encoding quality deteriorates.
[03:27:00 CEST] <tesseractcat> yeah, most i could get with ¨ffmpeg -framerate 24 -i output_%04d.png -c:v libx264 out.mkv¨ was about 0.2-0.3x speed
[10:22:05 CEST] <Adcock> what is resolution?
[10:22:32 CEST] <Adcock> Compare 1366x768 vs 1080o
[10:22:40 CEST] <Adcock> I am  not trolling.
[10:22:51 CEST] <Adcock> I don't understand the difference.
[10:22:54 CEST] <Adcock> :(
[10:50:50 CEST] <mixfix41> i thought you could play a file while capture x11??
[10:51:57 CEST] <mixfix41> i guess maybe some cases but i probs dont want to either since could record the audio of the launch video
[10:53:49 CEST] <mixfix41> with similar to ffmpeg -f x11grab -i :0.0 -i default -preset ultrafast -crf 18 -pix_fmt yuv420p file.mkv
[10:54:45 CEST] <mixfix41> though needd framerate + vid size in there
[10:58:21 CEST] <mixfix41> i like how ffmpeg puts the audio in convenient
[10:58:27 CEST] <mixfix41> oh thats pulse i guess
[20:58:37 CEST] <Thomas_J> Hi...
[21:02:45 CEST] <whitestone> does someone manage streamlink and live video in youtube?
[21:02:53 CEST] <whitestone> i have questions to do
[21:03:09 CEST] <whitestone> youtube change something about two days
[21:03:23 CEST] <whitestone> youtube-dl cant get anymore the m3u8 links
[21:04:36 CEST] <Thomas_J> I have an rtsp: IP camera with h264/720p output streaming to Facebook with a separate audio channel for external audio. I am using -c:v copy and ffmpeg decided that it will use 480p for output. Shouldn't it be outputing 720p?
[21:05:11 CEST] <whitestone> put the command
[21:05:37 CEST] <whitestone> no but it dont work in that way
[21:05:48 CEST] <whitestone> do you have youtube-dl in your machine
[21:06:09 CEST] <whitestone> this is a live transmission, i am dealing with that right now
[21:06:41 CEST] <whitestone> Thomas_j:send yhose commands, youtube-dl -F youtube link
[21:06:54 CEST] <whitestone> it will appear a list of possibilitties there
[21:07:19 CEST] <whitestone> Thomas_j, do you have the link?
[21:07:33 CEST] <Thomas_J> I am streaming to Facebook using rtmps. Not the same.
[21:07:39 CEST] <whitestone> or, can you share the link with us?
[21:08:05 CEST] <whitestone> i was thinking it was youtube
[21:08:18 CEST] <whitestone> never streamed for facebook
[21:08:40 CEST] <whitestone> you can use streamlink, it shows the option to download the video
[21:09:32 CEST] <Thomas_J> I'm sorry. I wasn't tying to answer you but ask a separate question. I am using ffmpeg to stream rtmps directly to Facebook.
[21:10:02 CEST] <Thomas_J> I am setting up Live streaming.
[21:10:36 CEST] <kepstin> whitestone: if youtube-dl stopped working, then you should check their github - they update fairly rapidly, and there might already be an issue open for the problem explaining what changed.
[21:10:41 CEST] <whitestone> i am trying to help you usle
[21:10:44 CEST] <whitestone> https://github.com/streamlink/streamlink/blob/master/src/streamlink/plugins/facebook.py
[21:10:59 CEST] <whitestone> check there, streamlink has a plugin
[21:11:10 CEST] <Thomas_J> As I say, I am not dealing with Youtube.
[21:11:31 CEST] <kepstin> Thomas_J: you need to share your comple ffmpeg output so we can read it and then tell you which part of the output explains why you're getting 480p
[21:11:47 CEST] <whitestone> i dont know if ffmpeg works with facebook, streamlink has a plugin and is supposed it works
[21:12:07 CEST] <whitestone> kepstin, i already say to share the link
[21:12:13 CEST] <whitestone> sory, not the link
[21:12:15 CEST] <whitestone> the commands
[21:12:22 CEST] <Thomas_J> If I wanted a 3rd party to stream through, I have my own dedicated server on line running nginx. But nginx doesn't do rtmps out.
[21:12:55 CEST] <kepstin> whitestone: Thomas_J is not trying to *play* a facebook stream, he has a completely different issue
[21:12:56 CEST] <whitestone> ok, if you dont share the command is difficult to help you
[21:13:12 CEST] <kepstin> Thomas_J: please ignore whitestone's stuff about youtube-dl, and just share your ffmpeg command *and complete output*
[21:13:13 CEST] <whitestone> he want to save it, isnt it?
[21:13:35 CEST] <Thomas_J> I have a full stream running live now. (with several weeks working on getting the right build.)
[21:13:37 CEST] <whitestone> and i told him to share the command
[21:14:23 CEST] <whitestone> ok, someone know how to get a mpd link to download dash videos from youtube?
[21:14:24 CEST] <pink_mist> whitestone: you're completely wrong on all counts
[21:14:33 CEST] <Thomas_J> That's okay, Yesterday, I was having a hard time to following what everyone was saying.
[21:14:47 CEST] <kepstin> whitestone: contact youtube-dl developers on their github. it might be that you just need a new version
[21:15:23 CEST] <kepstin> whitestone: they fix that kind of thing pretty quick - if it's not already fixed, check for or open an issue
[21:19:45 CEST] <Thomas_J> As I say, I have finally got a stream to Facebook working incorporating an external audio source. The way it's working is because I pulled all the strenuous commands out of the command string and just doing a -c:v copy.
[21:21:10 CEST] <Thomas_J> Problem now is that ffmpeg is not using the camera's input video size.
[21:21:22 CEST] <whitestone> i tested and is not working, i am asking here because there are many users and people with a lot of knowledge
[21:21:43 CEST] <whitestone> i was using ffmpeg with HLS and works grear
[21:22:08 CEST] <whitestone> but right now i dont know how to get the links to provide them to FFMPEG
[21:22:34 CEST] <whitestone> does someone know how to get links to let FFMPEG to download videos?
[21:23:32 CEST] <Thomas_J> Are you using rtsp: for an input stream?
[21:26:37 CEST] <Thomas_J> Sorry. I reread tour earlier text-lines. Good luck with that.
[21:30:58 CEST] <pink_mist> whitestone: mpv has a lua script that grabs links from youtube-dl and then hands them to ffmpeg to download https://github.com/mpv-player/mpv/blob/master/player/lua/ytdl_hook.lua .. if that doesn't help you, I don't know
[21:36:24 CEST] <Thomas_J> Incredible! My live stream is taking in and decoding 720p h264 with a separate audio input channel. It is re-encoding and streaming out rtmps to Facebook and all inside a Raspberry PI3 B+. I have had no drops, video stuttering or errors in over an hour.
[21:37:43 CEST] <Thomas_J> It looks like the RPi3b is going to work.
[21:38:23 CEST] <pink_mist> is it really re-encoding? thought you said you used -c:v copy
[21:39:54 CEST] <Thomas_J> The fact that it is re-encoding with the wrong 640p instead of 720p, I think it is.
[21:41:29 CEST] <pink_mist> oh, uh, well ok then :P
[21:46:04 CEST] <kepstin> if you used -c:v copy, then it is not re-encoding, therefore it is not changing resolution
[21:46:46 CEST] <kepstin> so either your camera is providing a different resolution than you think it is, or facebook is re-encoding it. If you share the ffmpeg output like I asked you do to, I could have told you which.
[21:47:16 CEST] <pink_mist> he already left
[21:47:27 CEST] <pink_mist> well, ping timeouted
[21:47:27 CEST] <kepstin> ah, nice
[22:22:06 CEST] <Thomas_J> The output of my IP camera has about a 3 to 4 second delay. I need to set a delay in the audio input channel to sync it.
[22:23:34 CEST] <yaymukund> hello, i am trimming and cropping some video and would like to just test it very quickly. I need the timing to be precise, but don't care about quality at all. What's the best encoding strategy?
[22:23:56 CEST] <yaymukund> I'm doing ultrafast -crf 0
[22:24:39 CEST] <yaymukund> (Would shrinking the video help any?)
[22:26:35 CEST] <yaymukund> hmm, maybe I shouldn't be using libx264. Sorry for the long question.
[22:26:46 CEST] <Thomas_J> I'm trying to think of what I can use to put in front of the camera with audio and it is not a copyrighted source to sync up the audio with the camera.
[22:28:16 CEST] <furq> yaymukund: -f nut -c:v rawvideo - | mpv -
[22:29:54 CEST] <yaymukund> ooo, interesting. for what it's worth I'm extracting many different sectons of a long video and joining them so I don't think I can simply pipe.
[22:30:03 CEST] <yaymukund> But that looks promising. I shall read more!
[22:30:16 CEST] <furq> well yeah nothing is quicker than rawvideo if you have the disk space
[22:30:32 CEST] <yaymukund> I do!
[22:36:47 CEST] <yaymukund> ooh, I could do filter_complex to get all the subsections in a single giant command
[22:54:28 CEST] <kepstin> yaymukund: note that x264 is probably faster with crf != 0, since (at least with 8-bit) 0 sets lossless mode
[22:54:40 CEST] <kepstin> although ymmv
[22:57:10 CEST] <kepstin> in some cases, resizing the video smaller using a low-quality resize method can speed things up. (with the default resize method, it can also slow things down)
[22:57:10 CEST] <linext> anyone watch season 2 of one punch man?
[00:00:00 CEST] --- Sat Jul 13 2019


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