[Ffmpeg-devel-irc] ffmpeg.log.20150613

burek burek021 at gmail.com
Sun Jun 14 02:05:01 CEST 2015


[00:00:58 CEST] <Mavrik> what does that window contain?
[00:05:06 CEST] <fortruce> The window is Hearthstone, a Blizzard game
[00:05:32 CEST] <fortruce> It seems to be specific to this window, but I can't figure out why it would matter what window
[00:06:24 CEST] <Mavrik> Well, it's an OpenGL game that's directly rendered on a GPU
[00:07:07 CEST] <fortruce> Oh :/
[00:07:38 CEST] <fortruce> Is there no capture device that would be able to gather that?
[00:10:14 CEST] <Mavrik> O.o
[00:10:21 CEST] <Mavrik> There's bunch of gaming capture software
[00:10:32 CEST] <Mavrik> including the ones bundled with the GPU drivers
[00:10:40 CEST] <Mavrik> they mostly hook into DirectX or OpenGL though
[00:11:09 CEST] <fortruce> alright, I'm trying to find a solution that I could trigger via command line so I can shell out to create the videos programmatically
[00:12:17 CEST] <feliwir> Can someone tell me where i can find a download link for libvp62?
[00:31:40 CEST] <fortruce> so, I switched over to using dshow and the screen-capture-recorder device, which works, but it's giving real-time buffer too full after a few seconds of recording, and I've already set the buffer to 2000M
[01:04:50 CEST] <jbmcg> hey there - wondering if anyone knows anything about how the "start" value gets set on a video. I'm trying to do a standard encode, not even adjusting times or anything, and somehow the duration / start value change
[01:04:55 CEST] <jbmcg> here's what I mean: http://pastebin.com/QjUZUxLa
[01:06:14 CEST] <jbmcg> wondering if there's a way to specify to keep that at 0 on the output file when encoding
[01:11:49 CEST] <zhr0> hi
[02:50:54 CEST] <orfios> is there any way to make n = seconds rather than frames? can I change the eval=frame to something that evals to seconds or milliseconds?
[02:53:18 CEST] <orfios> i need to mute the audio in a subregion of video. going to use if(gt(n, onset)*lt(n, offset)) and then set volume to 0 if that evals to true
[02:55:54 CEST] <c_14> use t instead of n?
[03:22:55 CEST] <orfios> what's wrong with this command?:
[03:22:57 CEST] <orfios> ffmpeg -i original_input.mp4 -af "volume='if(gt(t,3)*lt(t,6)+gt(t,8)*lt(t,10)0,1)'" -c:a libfdk_aac -strict -2 output.mp4
[03:23:18 CEST] <orfios> trying to mute 2 subregions of audio between 3-6 seconds and 8-10 seconds
[03:24:27 CEST] <c_14> That 0,1 at the end there looks pretty iffy to me
[03:25:03 CEST] <c_14> But if you don't provide your complete console output (on a pastebin service), we won't know what exactly isn't working
[03:27:08 CEST] <orfios> http://pastebin.com/Yy2YmTsK
[03:29:13 CEST] <c_14> Looks fine to me, what isn't working?
[03:30:09 CEST] <orfios> nothing is muted
[03:30:28 CEST] <orfios> like the conditions in the if statement aren't being evaluated the way i'm intending
[03:32:52 CEST] <orfios> i was doing the same thing with frames a little while ago and it was working, but not corresponding to the right times, leading me to think it's a variable framerate encoding
[03:33:19 CEST] <orfios> old command was along the lines of:
[03:33:21 CEST] <orfios> ffmpeg -i sample.mp4 -af "volume=volume='if(gt(n,250)*lt(n,625),0,1)':eval=frame" -c:a aac -strict -2 output.mp4
[03:33:24 CEST] <orfios> and it was working
[03:33:45 CEST] <c_14> You haven't set eval=frame in the not-working one
[03:33:49 CEST] <c_14> eval=once is default
[03:34:02 CEST] <c_14> If you want it to eval continually you'll need to explicitly set eval=frame
[03:34:10 CEST] <orfios> i see, that makes sense
[03:37:04 CEST] <orfios> thank you, it works now!
[03:37:20 CEST] <orfios> i really need to actually learn the ins and outs of ffmpeg and not just half ass my way through using it
[03:37:37 CEST] <orfios> it's a really powerful tool
[08:09:30 CEST] <ac_slater_> hey guys. I currently use `find_stream_info()` on my HLS and RTSP streams (via libavformat). This works but it's useless for me as I know everything about the streams ahead of time. What's the best way to "preconfigure" them
[08:12:01 CEST] <ac_slater_> my input source is an MPEGTS container with 1 video stream and 1 data stream
[08:13:38 CEST] <ac_slater_> I also dont use ffmpeg's decoders/encoders ... just mux/demux
[09:15:36 CEST] <ruby_on_tails> i recorded a video at 1920*1080 which looks very crisp on my ipad/macbook/mobile but looks horrible on a desktop whose resolution is 1360*768 why?
[09:16:54 CEST] <ruby_on_tails> horrible means the text is not crisp, its grainy at the edges, smaller text is blurred+grained
[10:08:21 CEST] <Fyr> guys, how to use replaygain in ffmpeg?
[10:08:37 CEST] <Fyr> I can't find anything in its documentation.
[10:17:18 CEST] <durandal_170> it just print some numbers
[10:18:28 CEST] <Canar> Same as ReplayGain anywhere else: calculate a loudness value, adjust gain accordingly. ^__~
[10:18:39 CEST] <Fyr> ok, how to make ffmpeg calculate it?
[10:18:46 CEST] <Fyr> and put it in the metadata?
[10:18:53 CEST] <Canar> metadata? idk
[10:19:00 CEST] <Canar> but ebur128 is the audio filter
[10:31:10 CEST] <Zucca> Anyone had problems with x264 two-pass encoding? I first did two-pass using x265... then exactly the same command lines, but replacing x265 with x264. Firdt pass goes ok, second faild right at the beginning.
[10:31:27 CEST] <Zucca> Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
[10:32:00 CEST] <Zucca> I've quadruplechecked everything. :P
[10:32:26 CEST] <Zucca> Only thing I'm not so sure about is the preset.
[10:32:53 CEST] <Zucca> Can I use different preset on passes?
[11:08:45 CEST] <relaxed> Zucca: why would you?
[11:09:31 CEST] <relaxed> use the same exact command, except for -pass. Pastebin your command and all output if you run into errors.
[11:13:59 CEST] <Zucca> relaxed: Would what? Use different presets on passes? Becuase first pass is for examining only? Right? I read on some forum that you could use different presets. That's false?
[11:22:16 CEST] <Zucca> It seems that fist pass goes trough much faster even if the presets are the same on both passes.
[11:23:23 CEST] <relaxed> sure, what's the error?
[11:25:08 CEST] <Zucca> relaxed: None anymore. :) Thanks.
[11:27:43 CEST] <Zucca> I'll make two-pass encodings using same preset from now on.
[14:20:13 CEST] <nifker> I installed ffmpeg like described but it can't find the command so I wanted to set the PATH but which path should I use for ffmpeg?
[14:20:28 CEST] <c_14> Where did you install it?
[14:20:37 CEST] <nifker> ffmpeg_build
[14:20:45 CEST] <c_14> Absolute path?
[14:21:09 CEST] <nifker> yes
[14:21:19 CEST] <nifker> ~/ffmpeg_build
[14:21:28 CEST] <c_14> export PATH="$HOME/ffmpeg_build:$PATH"
[14:25:00 CEST] <nifker> ok I will try this
[15:57:17 CEST] <GwaiLo> Hi, I'm trying to add some subtitles to a video without reencoding of the video stream. The answer I found online was using the following command `ffmpeg.exe -i video.mp4 -vf subtitles=video-english.srt out.mp4`
[15:57:24 CEST] <GwaiLo> when I run it though, I'm getting the following error
[15:57:38 CEST] <GwaiLo> Error while opening encoder for output stream #0:1 - maybe incorrect parameters
[15:57:39 CEST] <GwaiLo> such as bit_rate, rate, width or height
[15:58:13 CEST] <JEEBsv> the actual error is before that
[15:58:37 CEST] <JEEBsv> although I guess it's a case of you not making your command/line shell understand 100% what you meant
[15:59:11 CEST] <JEEBsv> also I'm pretty sure the vf will require re-encoding
[15:59:21 CEST] <GwaiLo> JEEBsv: ah, that would make sense. Sorry, I should have looked back further in the log (it had scrolled off screen). That's helpful. I've found a number of errors that I'll need to work through
[15:59:37 CEST] <JEEBsv> not to mention that ffmpeg's default is not "copy"
[16:00:17 CEST] <JEEBsv> so if you want to copy streams from input to output you will have to set it (-c[:a/:v] copy where -c copy is global and adding :a or :v will limit it to that)
[16:01:19 CEST] <GwaiLo> JEEBsv: That's what I thought. I assumed you couldn't burn in subtitles on top of a video without reencoding but the forum post suggested that I could so I was giving it a shot (when I've tried reencoding before, the lossy->lossy re-encode ends up just awful)
[16:01:30 CEST] <GwaiLo> (and takes forever)
[16:02:00 CEST] <GwaiLo> JEEBsv, thanks for that, those are some really good points. I think I have quite a bit more research to do constructing the command needed before seeing if it can work at all
[16:02:14 CEST] <JEEBsv> also ffmpeg by default selects the "best" audio and video stream so if you have more than one input stream of some type that you want to keep there's the -map parameter
[16:02:33 CEST] <JEEBsv> (f.ex. -map 0:a selects all of the audio streams from the first input file)
[16:03:33 CEST] <JEEBsv> anyways, you can try ffmpeg -i input.mp4 -i input.srt -c copy -c:s mov_text out.mp4
[16:04:50 CEST] <JEEBsv> that will add a mov_text subtitle track in addition to the "best" audio and video track in the mp4, muxing it into "mp4"
[16:05:45 CEST] <GwaiLo> JEEBsv, well, that's doing something
[16:06:06 CEST] <GwaiLo> GwaiLo, will let you know once it's finished processing what it's done :)
[16:08:38 CEST] <JEEBsv> shouldn't take too long unless the file is lolhueg
[16:10:00 CEST] <GwaiLo> JEEBsv, hmm, well, the output file is fine, works ok, but alas no subtitles
[16:10:49 CEST] <JEEBsv> the track should be there so if you use a player that supports that subtitle type it should work alright
[16:11:37 CEST] <JEEBsv> https://mpv.srsfckn.biz/ try drag and dropping it onto this
[16:15:23 CEST] <GwaiLo> JEEBsv, I'm downloading that to test. In VLC, it comes up with two subtitle tracks, one of them has nothing, and the other just has a permanent timestamp appearing
[16:16:16 CEST] <JEEBsv> the timestamp thing sounds like one of the ways of hacking chapters into mov/"mp4"
[16:18:37 CEST] <GwaiLo> JEEBsv, ok, with mpv I get the same results
[16:18:58 CEST] <JEEBsv> (´
[16:19:23 CEST] <GwaiLo> JEEBsv, maybe to cut past the attempts. As far as you know, is there any way to overlay a subtitle stream on an already encoded file and have it burnt in?
[16:19:52 CEST] <JEEBsv> well subtitles in "mp4" are kind of a herp derp thing (although 3gpp text should be around... and I thought that mov_text implemented something similar)
[16:20:06 CEST] <JEEBsv> what
[16:20:39 CEST] <JEEBsv> if you are implying that you can possibly change a video without re-encoding it then that's not possible
[16:21:06 CEST] <GwaiLo> JEEBsv, as I said before, I'm trying to burn in subtitles with no quality loss. It was only from a forum post that I found some suggestions that it was possible but it didn't quite sit right with me which is why I was asking about it here when it didn't work
[16:21:55 CEST] <GwaiLo> JEEBsv, and I'm sorry, I clearly didn't explain myself well enough before, I apologise if I've been wasting your time
[16:22:16 CEST] <relaxed> to hardsub you'll have to encode the video again, but it is possible with the subtitle filter
[16:22:17 CEST] <jcay> can one compile ffmpeg directly on FreeBSD?
[16:22:42 CEST] <JEEBsv> no quality loss is impossible, but by tweaking the preset and crf values with the libx264 encoder you should be able to get a result that's "good enough" for you
[16:23:00 CEST] <JEEBsv> having a subtitle track separate would be the best alternative
[16:23:05 CEST] <JEEBsv> are you limited to mp4?
[16:23:10 CEST] <JEEBsv> or can you use other containers?
[16:23:13 CEST] <relaxed> jcay: it's in /usr/ports
[16:23:28 CEST] <JEEBsv> jcay: why does that comment remind me of http://en.wikipedia.org/wiki/How_does_one_patch_KDE2_under_FreeBSD%3F
[16:23:31 CEST] <GwaiLo> hmm. It's to play on my mother in laws bravia tv. Let me double check the containers it supports
[16:23:47 CEST] <relaxed> jcay: but yes, you can, use gmake
[16:23:49 CEST] <JEEBsv> oh plastic toys with locked down software
[16:24:26 CEST] <GwaiLo> JEEBsv, unfortunately yes. I'm thinking I may be better off buying her some cheap set top box that supports separate subtitle files
[16:24:53 CEST] <JEEBsv> that to or something android-based so you could just put VLC for android there
[16:26:02 CEST] <GwaiLo> JEEBsv, looks like it supports mpeg1, mpeg2, mpeg4, divX, Xvid and wmv
[16:26:29 CEST] <JEEBsv> those sound like video stream formats rather than containers
[16:26:51 CEST] <JEEBsv> also I love how mpeg-4 literally means nothing
[16:27:03 CEST] <JEEBsv> because you have like 30 specifications under MPEG-4
[16:27:14 CEST] <JEEBsv> at least two that handle video, too
[16:27:15 CEST] <GwaiLo> "MPEG-4 (Part 2, 10), MP4" is what it says specifically
[16:27:21 CEST] <JEEBsv> oh
[16:27:29 CEST] <GwaiLo> sorry, I'm a little out of my wheelhouse
[16:27:35 CEST] <JEEBsv> that's more proper than I expected
[16:27:58 CEST] <GwaiLo> http://www.sony.com.au/support/compatibility/461525 They actually have a big long table with what they support (and even longer what they don't)
[16:28:24 CEST] <JEEBsv> well it does support matroska it seems
[16:28:48 CEST] <JEEBsv> so ffmpeg -i hurr.mp4 -i hurr.srt -c copy out.mkv
[16:29:02 CEST] <GwaiLo> yeah, that's what I started with originally. I had a mkv file and a separate subtitle file
[16:29:34 CEST] <GwaiLo> no, it doesn't support mkv (that final column has O's and X's for supported / unsupported). It tripped me up as well
[16:29:53 CEST] <JEEBsv> it says supported through USB, so does it mean it from some other type of input_
[16:30:33 CEST] <GwaiLo> JEEBsv, no, the table has both supported and unsupported (the legend is just above the table)
[16:30:47 CEST] <JEEBsv> well "supported from USB"
[16:31:07 CEST] <JEEBsv> anyways, it's a shit-on-shit sandwich
[16:31:10 CEST] <GwaiLo> yep
[16:31:30 CEST] <GwaiLo> and it doesn't support _any_ external subtitle files
[16:31:37 CEST] <GwaiLo> they just didn't build the support apparently
[16:32:14 CEST] <JEEBsv> none of the alternatives I gave were about having a separate file but just having a subtitle track around
[16:33:09 CEST] <JEEBsv> anyways, I guess the "safest" bet if you really can't put a nice android device there would be to re-encode and stick the subtitles there with either the subtitle or ass filter depending on input subtitle type
[16:33:48 CEST] <JEEBsv> ffmpeg -i hurr.mp4 [-vf something....] -c:v libx264 -crf 23 -preset medium -level 41 -c:a copy out.mp4
[16:34:08 CEST] <JEEBsv> with this you first encode a few thousand pictures
[16:34:16 CEST] <GwaiLo> JEEBsv, is the 'something' where I put the subtitle file?
[16:34:33 CEST] <JEEBsv> (-ss and -t can be useful, look at https://www.ffmpeg.org/ffmpeg-all.html )
[16:34:53 CEST] <GwaiLo> ok
[16:35:01 CEST] <JEEBsv> both the crf and preset are defaults
[16:35:23 CEST] <JEEBsv> first check if it looks good enough or bad, if it's bad you go down a value
[16:35:27 CEST] <JEEBsv> if it looks good you go up a value
[16:35:52 CEST] <JEEBsv> then at some point you find the highest crf value that still looks good enough for you
[16:36:35 CEST] <JEEBsv> after that you can start tweaking the preset. the "eyes" of the algorithm that decides the result of a CRF value will change, so you might have to do minor adjustments. preset is compression vs speed kind of thing
[16:36:49 CEST] <JEEBsv> so you pick the slowest prest that is still fast enough for you
[16:36:50 CEST] <GwaiLo> right, so the crf value is basically the output quality?
[16:36:54 CEST] <JEEBsv> no
[16:37:06 CEST] <JEEBsv> it's the closest we have to "constant quality" rate control, but it isn't
[16:37:08 CEST] <GwaiLo> JEEBsv, am I able to keep the original audio stream without it being reencoded?
[16:37:08 CEST] <JEEBsv> it's the rate factor
[16:37:18 CEST] <JEEBsv> yes, that's why I have the -c:a copy there
[16:37:20 CEST] <JEEBsv> :P
[16:38:18 CEST] <GwaiLo> ah, right. that makes sense :)
[16:39:03 CEST] <JEEBsv> http://web.archive.org/web/20150203203142/http://mewiki.project357.com/wiki/X264_Settings#preset
[16:39:09 CEST] <JEEBsv> presets are listed here, among other places
[16:40:22 CEST] <GwaiLo> wow, thank you, you're being incredibly helpful
[16:41:34 CEST] <GwaiLo> I'll start working through the options and see what comes up looking best.
[16:42:53 CEST] <GwaiLo> JEEBsv, one last question about it... I need to use chinese subtitles. It looks like I need to use the -sub_charenc GB18030 in there... would I put that before the -c:v ?
[16:43:39 CEST] <JEEBsv> sounds like a good place to put it, although I'm not sure if that parameter works with the vfs?
[16:44:07 CEST] <JEEBsv> to be quite honest I haven't used the subtitling support in ffmpeg since it's for the longest time been worse than when using mpv's capabilities for it
[16:44:35 CEST] <GwaiLo> JEEBsv, ok, sounds like something else I need to experiment with :)
[16:44:56 CEST] <JEEBsv> (mostly in relation to files containing fonts and stylized subtitle tracks, do note)
[16:44:56 CEST] <GwaiLo> normally I'd never worry about subtitling... I hate having subtitles burnt in, this just happens to be a special case
[16:45:39 CEST] <JEEBsv> yes, having the subtitles as a separate track is generally the best alternative
[16:48:53 CEST] <GwaiLo> JEEBsv, yep. Thank you for all your help, I'm going to go try a few different options and see what works well so will be dropping off.
[16:49:24 CEST] <GwaiLo> JEEBsv, p.s. just noticed you're in Finland... I spent a couple of weeks in Helsink and Tampere a few years ago, you have a beautiful country!
[19:51:56 CEST] <Relsak> Hello there! I'm transrating some live stream which seem to be both interlaced and progressive (if that's even possible). Am I safe to leave -flags +ildct+ilme?
[19:53:27 CEST] <JEEBsv> sounds like some ancient flags. do you want to deint or just re-encode?
[19:53:43 CEST] <Relsak> I v
[19:53:51 CEST] <Relsak> I want to leave it interlaced.
[19:54:10 CEST] <Relsak> So, reencode it is.
[19:54:17 CEST] <JEEBsv> well you'd be re-encoding it in any case
[19:54:39 CEST] <JEEBsv> or do you actually want to re-encode?
[19:54:47 CEST] <JEEBsv> or do you just want to pass the stream through?
[19:54:59 CEST] <JEEBsv> trying to see what you're trying to do :P
[19:56:41 CEST] <Relsak> I am doing transrating (from higher to lower bitrate), both mpeg to h264 and h264 to h264. But I'm bit confused with original strem being sometimes interaced, sometimes progressive (as reported by idet filter).
[19:58:08 CEST] <JEEBsv> ok
[19:58:18 CEST] <JEEBsv> a) I'm pretty sure you don't need those flags
[19:59:12 CEST] <JEEBsv> I mean, libx264 should be able to start the encoder in interlaced mode if the source says it's interlaced
[20:29:54 CEST] <SHOTbyGUN> how can I escape filename correctly in linux? Argument '01-57-24.flv'' provided as input filename, but ''/home/shotbygun/Videos/Record/2015-05-30\\' was already specified.
[20:41:27 CEST] <SHOTbyGUN> Same string works in bash, but not when executed by Java http://pastebin.com/JvPy1vz2
[20:47:20 CEST] <klaxa> i suggest splitting your parameters into single arguments and use exec(String[] cmdarray) instead of exec(String command)
[20:48:36 CEST] <chungy> Java isn't shell
[20:49:05 CEST] <SHOTbyGUN> alright thanks... yeah I have no idea what difference there is between shell bash command console tty virtualXterm etc...
[20:53:25 CEST] <fred1807> hello, I need help to convert some videos to raw .h264. But I need to overwrite source videos settings, I need a very specific raw h264 formatt, so it works on my raspberry system.  Right now, using only ffmpeg -i source.mp4 destination.h264  All the videos plays... But some breaks the loop functionality (it is a very restrict player, I guess it uses framerate).  Here is an example of metadata of a video that is working for me:
[20:53:26 CEST] <fred1807> http://pastebin.com/raw.php?i=wWuY4LHj  And here is an example of a video that breaks the  loop http://pastebin.com/raw.php?i=fFx9yx9L.  How can I force all the videos to the same format and the working example?  Btw, I am using ffmpeg from osx
[21:06:20 CEST] <chungy> looks like you should start by adding "-profile:v baseline -s 1280x720" to the output options
[21:25:33 CEST] <SHOTbyGUN> yay, it works now! thanks klaxa :3
[23:42:13 CEST] <Halit> Hey guys i wanted to join two different videos with different codecs and different frame sizes i wanted to use this code http://pastebin.com/aA28S9JP.  but i dont know how to edit [0:1][1:1] side. i wanted an output with 1280x720 frame size a mp4 file .  One of inputs 640x480 avi file  the other one 1920x1080 mp4 file
[23:45:12 CEST] <Halit> Anybody ?
[23:50:59 CEST] <Abbott> `-tag:a eng` should set the language of the audio to english, right?
[23:51:14 CEST] <Abbott> It isn't changing from German
[23:55:52 CEST] <c_14> -metadata:s:a:0 language=eng
[23:57:02 CEST] <Halit> hey c_14 did you see my question Please help me
[23:57:25 CEST] <c_14> Halit: eeeh, you want to downscale the 1080p one to 720p and the 480p one to 720p (and then pad the width)?
[23:58:15 CEST] <Halit> yeah
[23:58:54 CEST] <Halit> i cant handle [0:v]scale=1920:1080[v] with these part of codes
[23:59:27 CEST] <Halit> [0:v]scale=1920:1080[v] this for first input  and then what's next
[00:00:00 CEST] --- Sun Jun 14 2015


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