[Ffmpeg-devel-irc] ffmpeg.log.20141213

[burek]

[01:51] <maxtothemax> hi all
[01:51] <maxtothemax> if the audio codec string for a .ogg file is "FFVORBIS," does that mean it was encoded with ffmpeg's built-in vorbis encoder, or might it have been encoded with libvorbis
[01:52] <pzich> or maybe it's https://godoc.org/code.google.com/p/ffvorbis-go/ffvorbis ?
[01:52] <maxtothemax> oh
[01:53] <maxtothemax> I've been downloading vorbis files from bandcamp, I just wondered if they were using libvorbis or not
[01:53] <maxtothemax> since that's supposed to be the best encoder
[10:44] <waressearcher2> if I use "-ss" and "-t" before "-i 1.avi" it will apply to input file and if I use them after they will apply to output file ?
[10:45] <ubitux> -ss before -i will cause a "seek call" to your input, which might not be accurate, putting it after is as "output option" indeed but this means it will allow accurate "seeking" (no seek will be performed)
[10:46] <ubitux> for -t, i would say it's the same assuming it actually works as input option; afaik it's only output but i might be wrong
[11:04] <waressearcher2> what is better codec to use for video while editing it ? I usually convert video from "mkv" or "mp4" to "avi" with "mpeg4" codec, that way I can edit it precisely
[11:06] <ubitux> mpeg4 is lossy, it's insane to edit that way
[11:06] <waressearcher2> I use 5000k bitrate or sometimes 10000k
[11:07] <ubitux> it's still lossy
[11:07] <ubitux> use huffyuv, ffv1, utvideo or similar
[11:07] <waressearcher2> ubitux: especially when you want split and join pieces if its in h264 codec its not precise
[11:07] <waressearcher2> ubitux: even if its lossy that way it keeps smaller size
[11:08] <ubitux> do what you want, successive lossy encodes is a madness
[11:08] <ubitux> you should never edit that way
[11:11] <waressearcher2> 'is a madness', no this is ffmpeg
[11:11] <waressearcher2> and console video editing, welcome to linux
[11:15] <waressearcher2> there is a filter to make video fade out: -vf "fade=out:4751:400",   is there a way to tell it to fade out from first frame to the last I don't want to calculate amount of frames myself, if I use "fade=out:0:-1" it says "Error setting option nb_frames to value -1" and if I use "fade=out:0:0" it says "Floating point exception"
[11:17] <waressearcher2> wait
[11:21] <waressearcher2> I can just use "fade=out"
[11:24] <waressearcher2> if I use "-ss" after "-i" I can't just seek to some position, for example that command: "-i ../1.avi -ss 387 -t 2 -vcodec copy" seeks to 387 second and copied 2 seconds of video but if I use some codec instead of copy like that command: "-i ../1.avi -ss 387 -t 2 -vcodec mpeg4" it starts to decode all frames in source video until 387 second, how to
[11:24] <waressearcher2>  avoid decoding of first 387 seconds of video ?
[11:41] <Kriss_> Hello. Once again I'm trying to find help about how to get screenshots from video with the exactly the same quality as in the video by means off ffmpeg and c++
[11:41] <Kriss_> in particular I try to use this example, but quality is very bad https://trac.ffmpeg.org/ticket/3090?cversion=2&cnum_hist=2
[11:44] <waressearcher2> Kriss_: can't you use mplayer and hotkey to have screenshoot ?
[11:46] <Kriss_> nope. I need exactly ffmpeg and nothing else ... even external libs are not welcome since ffmpeg can save jpegs by itself
[12:33] <Kriss_> I believe in you guys) help me please
[14:06] <Kriss_> weekend? (
[14:12] <DrSlony> Kriss_ :)
[14:12] <DrSlony> how many days has it been now?
[14:15] <Kriss_> :-\
[14:17] <Kriss_> I wonder what for channels like this exist?
[14:20] <DrSlony> maybe better if you submit a complete bug report showing what you tried and describing what you expect to get
[14:52] <c_14> Kriss_: try asking on the user mailing list
[16:53] <marsfligth> Hi, how to list the video codecs recursively inside a folder containing many different kind of video format and codecs? I mean something like this http://mediaarea.net/en/MediaInfo but tu use in batch mode. Thanks
[17:02] <Filarius> maybe use ffprobe on each file ?
[17:05] <wyatt8740> how can I fix out of sync audio by delaying the sound by x milliseconds?
[17:25] <c_14> wyatt8740: -itsoffset
[18:03] <wyatt8740> c_14: thanks
[18:04] <wyatt8740> though I found a ground loop buzz in my audio so I'm redoing it. Will have to try in a bit
[18:42] <phil4000n> Hello, I'm some basic question about the ffmpeg user forum which I subscribed to.
[18:42] <phil4000n> How comes that I received email, but I can't post by sending an email to ffmpeg-user at ffmpeg.org, which an attachement?
[18:44] <JEEB> if that e-mail you subscribed to the mailing list with matches the one you sent an e-mail with to the list, it should appear. unless you have a big attachment there
[18:44] <JEEB> because in case of attachments it might end up in moderation
[18:44] <JEEB> poking the person in charge of that mailing list might work in that case
[18:45] <JEEB> make sure that your e-mail never showed up by checking the web archive
[18:47] <phil4000n> Is it than possible to put external links, such as google drive or other, so that people can possibly check themself?
[18:48] <phil4000n> Attachement were 611 kb + 640 kb
[20:56] <bencc> can I use h264 -preset veryslow on all desktop browsers?
[20:56] <bencc> is there a reason not to use it?
[21:32] <tnelsond> I'm using ffmpeg to burn subtitles into a video (I think they're bitmap subtitles) but when I burn them in they are really faint. How do I up the alpha or change the contrast of the overlay?
[21:33] <c_14> bencc: the only reason not to use -preset veryslow is if you're impatient
[21:34] <wyatt8740> I need to see an example
[21:34] <wyatt8740> how are you burning them
[21:35] <tnelsond> ffmpeg -i ~/Holl/makemkv/IW_CHRISTMAS_2005/title00.mkv -filter_complex "[0:v][0:s:0]overlay[v]" -c:a copy -map '[v]' output.mkv
[21:37] <tnelsond> The subtitles also appear very faint when viewed from the source which is not burned. (But when played from the source on an actually DVD player they're not faint)
[21:37] <klaxa> i didn't know overlay supported subtitles as video input, have you tried the subtitles or ass filter instead?
[21:38] <c_14> klaxa: subtitles/ass only supports text subtitles
[21:38] <c_14> overlay is used for picture subtitles
[21:38] <klaxa> oh
[21:38] <tnelsond> Should I just ocr the subtitles and rerender them?
[21:38] <klaxa> okay, makes sense
[21:38] <c_14> tnelsond: what format are they?
[21:38] <klaxa> does overlay support alpha?
[21:39] <tnelsond> I don't know. They're just vobsub subtitles I guess. I ripped them to an mkv because I wasn't able to get them to be ripped with ffmpeg off of the vob file.
[21:40] <tnelsond> s/mkv/makemkv
[21:42] <c_14> tnelsond: if you play the file with a video player, do the subs look the same as when they're burned in or different?
[21:43] <tnelsond> c_14: They both look about equal. Both faint.
[21:55] <c_14> If the subtitles are dvdsub, you can try setting the color palette with -palette
[21:56] <c_14> The option is "documented" here: https://ffmpeg.org/ffmpeg-codecs.html#dvdsub
[21:56] <c_14> Not entirely sure what each number represents.
[21:56] <c_14> At least one of them should be alpha though...
[21:56] Action: c_14 hopes
[22:03] <tnelsond> Codec AVOption palette (set the global palette) specified for output file #0 (output.mkv) is not an encoding option.
[22:04] <c_14> It's an input option.
[22:04] <c_14> put it before the input file.
[22:06] <tnelsond> Hmm... that palette thing doesn't appear to have changed anything.
[22:10] <c_14> Try muxing the subs to a separate file with ffmpeg -i in.mkv -c copy -an -vn out.sub; then using ffmpeg -i in.mkv -palette [foobar] -i out.sub -map 0:a -filter_complex '[0:v][1:s]overlay[v]' -map '[v]' out.mkv
[22:14] <tnelsond> Output file #0 does not contain any stream
[22:14] <tnelsond> Is this because I have 2 subtitle tracks?
[22:24] <tnelsond> Thanks for the help c_14. I guess I'll just do some more reading and tinkering and see if I can get this working.
[22:50] <bencc> c_14: thanks
[00:00] --- Sun Dec 14 2014