[Ffmpeg-devel-irc] ffmpeg.log.20150924

[burek]

[01:30:30 CEST] <Senshi>   Hey guys, quick question! I'm using "-ss" to seek to a specific time to extract a single frame from (as PNG). The problem is sometimes the time passed in is bigger than the video's duration, resulting in empty output. Video filters have some vars to use so you can do checks like "if(gt(a,...))"; does something similar exist to ensure -ss seeks to the end of the file at maximum? Thanks!
[01:41:53 CEST] <Nate__> Hello.  I found that ffmpeg supports the MPEG-DASH muxer via "-dash" format but I can't find any documentation on its use.  Does it re-use webm_dash_manifest format options?
[01:42:51 CEST] <waressearcher2> what is it for ? mux audio and video downloaded from youtube ?
[01:44:42 CEST] <Nate__> I downloaded this movie: https://durian.blender.org/ and added english and spanish subtitles.  I got ffmpeg to dash the video but the subtitles don't show up.
[01:45:09 CEST] <Nate__> And I just can't find any help at all with the "-dash" format
[01:48:23 CEST] <waressearcher2> Nate__: is that their new project ? latest I watched was that live action movie they made with robots 2 years ago, have they made another one ?
[01:48:26 CEST] <Senshi> Please ignore my question; found a workaround. Cheers!
[01:48:46 CEST] <waressearcher2> Senshi: what was the workaround ?
[01:49:29 CEST] <Senshi> waressearcher2: I'm running FFmpeg as a subprocess from AIR (don't ask); I just stop running FFmpeg after the first empty frame output ;_
[01:50:12 CEST] <Nate__> waressearcher2: I have no idea, it was just a video I found with some subtitles to try and use.  ffmpeg/ffplay sees the subtitle tracks, and VLC displays them fine, but ffmpeg will not dash the subtitles out even though subtitles are supported in the MPEG-DASH standard.
[01:51:22 CEST] <Senshi> (RE Blender video: their latest one is called Cosmos Laundromat)
[01:56:25 CEST] <Nate__> Has any documentation been written, or should I just try and read the source code?  I couldn't find the commit of it because I thought that it was recent.
[01:58:51 CEST] <c_14> Nate__: ffmpeg -h muxer=dash
[02:03:35 CEST] <Nate__> c_14: cool, that works, but it doesn't mention subtitles tracks or having to manipulate the adaptation sets.  I'm looking at ffmpeg dated Sep 19.
[02:06:38 CEST] <c_14> Then it might not be supported.
[02:07:08 CEST] <waressearcher2> how old ffmpeg should get to not be supported ? 2 days ?
[02:07:32 CEST] <c_14> Goes with what feels right.
[02:07:52 CEST] <c_14> I pay decent attention to the devel mailing list so I usually know how new certain features are, etc.
[02:08:24 CEST] <c_14> s/Goes/Go/
[02:09:13 CEST] <c_14> And the last commit to the dash muxer was May, so.
[02:13:59 CEST] <Nate__> c_14: thanks for checking.  That's a bummer that development stopped short of carrying along subtitles.
[02:14:19 CEST] <c_14> Open/check for a feature request on trac.
[02:20:33 CEST] <Nate__> c_14: I might follow up on the mailing list for more info and may verify that it is indeed unsupported.
[02:23:33 CEST] <Nate__> Although reading the dashenc.c  file, I see where it's writing the mpd file out and it doesn't appear like it's been made to be that flexible.  I do see an error when ffmpeg runs saying "No bit rate set" for the subtitle track: http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavformat/dashenc.c;h=7a932147e57d2ef12e408c9901b817f1594cd9da;hb=f94af8d32ae3c2df19d3e0d27ac230e9bd742a91#l598
[02:39:29 CEST] <PlanC> is it possible to cut an MP3 and at the same time keep the ID3 metadata?
[02:43:52 CEST] <c_14> should do that by default
[02:46:12 CEST] <PlanC> with which command?
[02:46:16 CEST] <PlanC> I'm using: ffmpeg -t 30 -i inputfile.mp3 -acodec copy outputfile.mp3
[02:46:25 CEST] <c_14> should work
[02:47:00 CEST] <PlanC> I've tried that and it doesn't come with the ID3
[02:48:11 CEST] <c_14> works for me
[02:51:11 CEST] <PlanC> really?
[02:51:18 CEST] <c_14> yep
[02:51:19 CEST] <PlanC> can you try it with this MP3: http://ge.tt/api/1/files/3syorQO2/1/blob?download
[02:51:30 CEST] <PlanC> it's the one that I'm using and failing with
[02:52:16 CEST] <c_14> yep
[02:52:24 CEST] <c_14> What version are you running?
[02:56:01 CEST] <PlanC> wow!
[02:56:52 CEST] <PlanC> ffmpeg version git-2015-09-15-6d1801b
[02:58:31 CEST] <c_14> Hmm, I'm still running a build from the 6th.
[03:03:39 CEST] <PlanC> c_14, really strange
[03:03:50 CEST] <PlanC> the ID3 is actually in the file, but it's not showing in VLC for me
[03:03:59 CEST] <PlanC> I had to use: http://web.ist.utl.pt/antonio.afonso/www.aadsm.net/libraries/id3/ to check the ID3
[03:04:07 CEST] Action: c_14 just uses ffprobe
[03:04:08 CEST] <PlanC> how are you checking the ID3?
[03:04:33 CEST] <PlanC> wonder why VLC isn't picking it up
[03:09:46 CEST] <PlanC> ah alright
[03:10:05 CEST] <PlanC> FFmpeg is using ID3 V2.4
[03:15:58 CEST] <c_14> You can write v2.3 with -id3v2_version 3 or enable legacy ID3v1 tags with -write_id3v1 if you think that's the "problem"
[03:16:03 CEST] <PlanC> exactly, yeah
[03:16:05 CEST] <PlanC> just found that
[03:16:07 CEST] <PlanC> thanks man!
[03:16:33 CEST] <PlanC> also, do you think it's better to use ID3v1?
[03:18:22 CEST] <c_14> If you're going for most supported, probably. They are deprecated though.
[03:56:06 CEST] <x41> when using nvenc how do you get a constant bit rate. minrate and maxrate do not seem to have an effect.
[04:02:53 CEST] <x41> would it be possible to add bit rate padding to nvenc? haha
[04:52:56 CEST] <GoldenH> hello. can I get some help installing yasm or understanding compand?
[06:11:53 CEST] <x41> GoldenH, You should go to your distribution channel on asking how to install yasm. when you have installed yasm a manpage will be available via man yasm in your console.
[06:12:15 CEST] <waressearcher2> obviously
[06:13:06 CEST] <waressearcher2> Topic for #yasm: WELCOME TO 0x71.org support channel :) . Come to Our Church http://www.tjc.org
[06:13:36 CEST] <GoldenH> thanks x41 i have figured all that out now
[06:13:39 CEST] <GoldenH> except compand
[06:13:51 CEST] <GoldenH> yasm is working and ffmpeg is compiled
[06:15:01 CEST] <GoldenH> had to give up on x265 is all
[06:27:21 CEST] <loa> can somebody again say how i can test what options ffmpeg are for nvenc code?
[06:27:32 CEST] <loa> there was something like ffmpeg -vcondec nvenc -h
[06:27:42 CEST] <loa> can you fix my command please?
[07:37:54 CEST] <relaxed> loa: ffmpeg -h encoder=nvenc
[07:43:26 CEST] <loa> relaxed, lol, you are very friendly, thx)
[09:46:24 CEST] <satiender> Hi , Which is better between FFmpeg or Gstreamer for video-Encoding , Muxing , filtering ??
[09:46:35 CEST] <satiender> Anybody can help ??
[09:48:55 CEST] <fritsch> satiender: find out yourself ... ever asked in a mercedes shop if bmw is to be prefered?
[09:54:38 CEST] <satiender> ok sir
[11:49:16 CEST] <Nico___> Hi ! I need some help with ffmpeg. I'm working on an android application wich get audio from a video file. This is my command : "ffmpeg -i video.mp4 -vn -ac 2 -ar 44100 -ab 320k -f mp3 output.mp3", but still not working...
[11:49:28 CEST] <Nico___> Someone can help me please ?
[12:28:49 CEST] <ehsanv> hi, is this possible to convert srt to vobsub with ffmpeg? i know there's a tool for linux srt2sub, but i'm in windows and can't use it. thanks
[12:36:52 CEST] <techtopia> Nico___
[12:37:59 CEST] <techtopia> ffmpeg -i input.mp4 -acodec copy output.mp3
[12:38:08 CEST] <techtopia> assuming the file has mp3 audio
[12:38:32 CEST] <techtopia> you can change extension to whatever it is, .mp2 .ac3 .m4a etc.....
[12:46:47 CEST] <Nico___> techtopia
[12:46:56 CEST] <Nico___> thx for your answer
[12:47:08 CEST] <Nico___> But still not working and i don't know why...
[13:58:21 CEST] <ehsanv> Nico___: you want to extract audio from video?
[15:02:17 CEST] <Nico___> ehsanv : Yeah, sry i'm late.... I managed to extract an ogg audio track from a mp4 video. Then i just convert it into an other format
[17:30:17 CEST] <__sam> does ffmpeg support gpu acceleration on raspbian?
[21:20:29 CEST] <DrSlony> Hello, is it possible to make a video out of several images by specifying whole filenames instead of glob?
[21:21:06 CEST] <c_14> If you mess around with concat, sure. Otherwise use image2pipe and cat
[21:21:12 CEST] <c_14> (the image2pipe format)
[21:21:39 CEST] <DrSlony> could you show an example command?
[21:22:14 CEST] <c_14> cat a.png b.png c.png d.png | ffmpeg -f image2pipe -i pipe:0 out.mkv
[21:22:36 CEST] <DrSlony> thank you
[21:57:31 CEST] <Zenk_BR> Hey, good afternoon
[21:57:49 CEST] <waressearcher2> 5:55am here
[21:58:03 CEST] <Zenk_BR> sorry hahah. good morning for u
[21:58:20 CEST] <Zenk_BR> Brazil is 4:48 pm
[21:59:31 CEST] <waressearcher2> its friday here
[21:59:36 CEST] <waressearcher2> you still in the past ?
[22:01:34 CEST] <Zenk_BR> Thursday here
[22:01:39 CEST] <Zenk_BR> kkk yes
[22:01:42 CEST] <Zenk_BR> i'm in the past haha
[22:01:58 CEST] <Zenk_BR> sorry for my english..ok? rsrs
[22:09:18 CEST] <Zenk_BR> i would like make a question
[22:10:27 CEST] <c_14> Just ask, if someone can help you they will.
[22:11:00 CEST] <Zenk_BR> i am try convert .dav to .avi with ffmpeg, but have some errors
[22:12:17 CEST] <Zenk_BR> i have 2 archives for make tests. the first have 1 min~. when i convert, the file don't have audio
[22:13:07 CEST] <Zenk_BR> when i try convert the second archive (20min~) It appears several errors, no audio, and the video turns gray after a few minutes
[22:19:10 CEST] <waressearcher2> Zenk_BR: your inglish is allright
[22:19:41 CEST] <c_14> Zenk_BR: any errors in the ffmpeg output?
[22:21:11 CEST] <Zenk_BR> yes, can i put here the code and erros?
[22:36:08 CEST] <ingvarha> is it possible to record audio from and alsa sink while using x11grab ?
[22:36:18 CEST] <Mavrik> Yes.
[22:36:31 CEST] <ingvarha> like in
[22:36:32 CEST] <ingvarha> PULSE_SOURCE=alsa_output.pci-0000_00_1b.0.analog-stereo.monitor arecord --format=S16_LE --rate=44100 --channels=2 output.wav
[22:37:21 CEST] <ingvarha> if I just say 'ffmpeg -f alsa -i hw:1 ...', the sound is terrible, so there is something I dont get correct
[22:37:51 CEST] <ingvarha> is hw:1 enough, and I'm just lacking the correct settings for sample rate, channels, etc
[22:38:05 CEST] <ingvarha> or can I give PULSE_SOURCE to ffmpeg in any way?
[22:39:20 CEST] <kepstin-laptop> if you're using pulseaudio, you could use ffmpeg's native pulseaudio format rather than alsa...
[22:40:09 CEST] <kepstin-laptop> I presume that PULSE_SOURCE env variable is being interpreted by the alsa pulseaudio module
[22:40:31 CEST] <kepstin-laptop> while using ffmpeg -f alsa -i hw:1 means ffmpeg is accessing the hardware directly via alsa, bypassing pulseaudio
[22:42:31 CEST] <ingvarha> so -f alsa -i hw:1  sounds most correct. So, how do I specify "cd quality" for an avi output, for example
[22:42:37 CEST] <kepstin-laptop> so for this example, you could use "ffmpeg -f pulse -i alsa_output.pci-0000_00_1b.0.analog-stereo.monitor ..."
[22:48:51 CEST] <ingvarha> kepstin-laptop: ah, that makes sense. I was trying to use -f alsa with the pulse source
[22:49:00 CEST] <ingvarha> works fine with -f pulse :-)
[22:49:05 CEST] <ingvarha> kepstin-laptop: thanks
[22:49:31 CEST] <Zenk_BR> c_14, can i put the code and errors here?
[22:49:40 CEST] <c_14> zack6849: upload them to a pastebin service
[22:49:52 CEST] <c_14> s/zack6849/Zenk_BR/
[22:49:56 CEST] <c_14> sorry zack6849
[22:52:34 CEST] <Zenk_BR> http://pastebin.com/mz0HtP6s
[22:55:26 CEST] <c_14> That input file doesn't have an audio track. Also the vbr option isn't being used, and the h264 looks either malformed or in a not-yet supported format.
[22:57:55 CEST] <Zenk_BR> hmmmm
[22:58:51 CEST] <Zenk_BR> exist one software can be it's conversion, but is manual...and i have to do automatic...and with this program the video have audio...
[22:59:08 CEST] <Zenk_BR> so...i will try another way
[23:00:55 CEST] <Zenk_BR> You know some method that I could try ?
[23:01:13 CEST] <c_14> Does `ffprobe' detect an audio stream in the file?
[23:01:21 CEST] <c_14> Or any other stream besides the video one?
[23:03:24 CEST] <Zenk_BR> I could not understand your question...
[23:03:52 CEST] <c_14> Run `ffprobe filename' and check if it lists an audio stream and/or if it lists any streams besides the video stream
[23:04:25 CEST] <Zenk_BR> ok
[23:06:18 CEST] <Zenk_BR> http://pastebin.com/qWxDTzVC
[23:19:31 CEST] <c_14> Hmm, nah. It can't find anything.
[23:20:03 CEST] <c_14> If you can upload a sample of the file, you could open a feature reqest on trac.
[23:20:06 CEST] <c_14> But other than that *shrug*.
[23:20:44 CEST] <Zenk_BR> i will do it
[23:20:50 CEST] <Zenk_BR> thank you so much o/
[00:00:00 CEST] --- Fri Sep 25 2015