[Ffmpeg-devel-irc] ffmpeg.log.20131116

burek burek021 at gmail.com
Sun Nov 17 02:05:02 CET 2013


[01:10] <jure> can I normalize audio with ffmpeg?
[01:18] <jure> say "ffmpeg -i input.wav -af normalize=0.0 -o n.wav" to normalize the amplitude to 0db
[01:31] <llogan> jure: see tools/normalize.py although ive never tried it
[02:13] <ussher_> is it possible to record the pulse monitor and the pulse default (mic) via ffmpeg options?  here is what I have now, but its either mic, OR system sounds. http://pastebin.com/MfGUheFn
[11:01] <LithosLaptop> How do I get ffmpeg to accept multiple images as input that are not in a sequence?
[11:01] <LithosLaptop> a whole folder
[11:01] <LithosLaptop> ffmpeg without glob support
[11:11] <LithosLaptop> hmm the wiki isn't helping :(
[11:12] <LithosLaptop> another problem is I want to the output to be 1920x1080, but the aspect ration still need to be kept
[11:12] <LithosLaptop> so I need to add black bars top/bottom or right/left
[11:13] <LithosLaptop> I tried this as suggested in the wiki: https://trac.ffmpeg.org/wiki/Scaling%20%28resizing%29%20with%20ffmpeg
[11:13] <LithosLaptop> -vf scale="'if(gt(a,16/9),1920,-1)':'if(gt(a,16/9),-1,1080)'"
[11:14] <LithosLaptop> but then I get 1613x1080 on one of the images and ffmpeg bombs out with: [libx264 @ 026d74e0] width not divisible by 2 (1613x1080)
[11:14] <LithosLaptop> just want it to add blackness so that it reaches 1920x1080
[11:28] <LithosLaptop> ok so I know it will either be 1920xsomething or somethingx1080 after scaling but how do I automatically add borders so that the output is 1920x1080?
[11:29] <LithosLaptop> it seems to be easy if I actually know the resolution of the source or what the scaled resolution will be
[11:35] <diesel420> nobody like black bars
[11:37] <LithosLaptop> umm lol thats not the answer I was expecting
[11:38] <LithosLaptop> nobody likes stretching
[11:38] <LithosLaptop> :)
[11:43] <diesel420> i cant help, sorry. you want create a video slideshow from several images with different resolutions?
[11:45] <LithosLaptop> yep
[11:46] <LithosLaptop> ok found something that works :)
[11:46] <LithosLaptop> scale='gte(iw/ih\,1920/1080)*1920+lt(iw/ih\,1920/1080)*((1080*iw)/ih):lte(iw/ih\,1920/1080)*1080+gt(iw/ih\,1920/1080)*((1920*ih)/iw)',pad='1920:1080:(1920-gte(iw/ih\,1920/1080)*1920-lt(iw/ih\,1920/1080)*((1080*iw)/ih))/2:(1080-lte(iw/ih\,1920/1080)*1080-gt(iw/ih\,1920/1080)*((1920*ih)/iw))/2:black'
[11:46] <diesel420> congrats
[11:50] <LithosLaptop> lol the encoded file only shows black
[11:50] <diesel420> :/
[11:55] <LithosLaptop> I've got an idea :)
[11:55] <LithosLaptop> bbl
[12:06] <vl4kn0> Hi, I have fps filter successfully setup, but I can't find how to use it in the application. Is the video stream automatically filtered or do I need to do the filtering myself?
[12:15] <ac> hello, I would like to make a screencast *with audio*, to record video games, and every time I try, I get distorted audio (like if the track was played slower). I've tried different versions of ffmpeg, different audio recording options, it doesn't change anything. I've seen many people on the forums/mailing-lists with the same problem, but no solution.
[12:16] <ac> I'm on debian, btw, and I use pulseaudio because there's no way to record audio with alsa apparently
[12:19] <ac> ffmpeg version is 2.1 from deb-multimedia, but I have the same problem with 1.2.4
[12:20] <Ozzapoo> Hi. Can someone please help me? I'm not sure what's wrong... http://pastebin.com/0gvTryFt
[12:21] <Ozzapoo> I'm piping raw h264 output from my webcam to ffmpeg in this
[12:33] <Ozzapoo> Doh. It's because I didn't create the directory for the segments
[12:33] <Ozzapoo> it works now!
[12:33] <Ozzapoo> :D
[12:52] <ac> aaaaaaaaand it magically works
[12:52] <ac> aaaaaaaaaaand it magically doesn't work again
[12:55] <davo> i'm trying to build a package from source (opencv-2.2.0) that needs ffmpeg, not sure which version, I've tried 0.5.x to 0.8.10, but they all die at "cap_ffmpeg.cpp:419:52: error: ‘av_open_input_file’ was not declared in this scope"
[12:56] <davo> any idea what version ffmpeg i need to compile this version of opencv
[12:56] <davo> (just thought i'd ask here #opencv is a little sleepy atm)
[12:57] <davo> thanks in advance
[13:02] <ac> ok, speculation 1 : it works on first launch after reboot /o\
[13:03] <ac> great
[14:41] <vl4kn0> Is here anyone who could help me get my filtering right (programatically using libavfilter)?
[14:43] <Compn> vl4kn0 : ask on mailing list yet ?
[14:43] <Compn> vl4kn0 : saste might know :)
[14:43] <vl4kn0> Compn: haven't asked on mailing list, might give it a shot
[16:03] <Bombo> is it possible to mux foo.mp4 + foo.sub + foo.idx into one foo.mkv? (vobsub subtitles)
[16:06] <Compn> you guys and your vobsub subtitles
[16:06] <Compn> try mkvmerge ?
[16:06] <Compn> ehee
[16:06] <Compn> vobsubs may also work
[16:08] <sacarasc> Or OCR them. :D
[16:09] <Bombo> hm ;)
[16:13] <Compn> download the text version from opensubtitles.org
[16:32] <ubitux> Bombo: yes it's possible
[16:33] <ubitux> ffmpeg -i foo.mp4 -i foo.idx -map 0 -map 1 -c copy out.mp4
[16:33] <ubitux> ffmpeg -i foo.mp4 -i foo.idx -map 0 -map 1 -c copy foo.mkv
[16:33] <ubitux> sorry :)
[16:33] <ubitux> assuming supported codecs
[18:11] <Bombo> ubitux: ah indeed, works ;)
[18:12] <ubitux> :)
[18:12] <Bombo> needed to add more -map magic
[18:12] <ubitux> make sure you use git head though, i fixed some stuff in vobsub recently, which i didn't backport yet
[18:12] <Bombo> got two audio streams, two sub streams
[18:13] <Bombo> yep, used a recent win build
[18:14] <Bombo> on my linux box i guess i have to compile myself a recent git version
[18:14] <vl4kn0> How can I get % of frames decoded?
[18:15] <Bombo> i'm still missing an ETA: while encoding... why isn't that included yet?
[18:15] <Bombo> x264 got a nice ETA ;)
[18:16] <Bombo> ffmpeg version N-57996-gdd3d0f4 Copyright (c) 2000-2013 the FFmpeg developers built on Nov  9 2013 18:07:24 with gcc 4.8.2 (GCC)
[18:17] <Bombo> ubitux: recent enough? oh you added the vobsub support, thx then ;)
[18:18] <ubitux> vobsub demuxing is in ffmpeg since a while, but i fixed some bugs in the demuxer "recently"
[18:18] <ubitux> (one month ago or so)
[18:19] <Bombo> seems to work
[18:20] <Bombo> but switching between subs and or audiostreams in vlc, makes it a little asynched, but its probably vlc's fault
[18:24] <ubitux> try mpv ;)
[20:13] <Samus_Aran> anyone know of any AAC encoders that can handle 24 or 32bit audio?  libfdk_aac can only handle 16bit audio, not DVD or Blu-Ray quality.  though it can handle 96KHz sampling rate.
[20:17] <LithosLaptop> Samus_Aran: AAC is a lossy codec; sound quality usually is the goal not sampling rate and bit depth
[20:18] <LithosLaptop> perceived audio quality
[20:25] <LithosLaptop> Samus_Aran: libfdk_aac is the best AAC encoder you can use with ffmpeg; the other encoders give worse sound quality. If you don't need to use ffmpeg then you can also try Apple's AAC encoder
[20:34] <JEEB> just fyi
[20:34] <JEEB> AAC has no "bit depth"
[20:34] <JEEB> no lossy format in general has a concept of "bit depth"
[20:35] <JEEB> (this is shown in libavcodec by the fact that most if not all lossy decoders output float by default)
[20:53] <Samus_Aran> JEEB: meaning it uses arbitrry precision based on available bitrate?
[20:54] <Samus_Aran> I guess I'm trying to figure out why Blu-Ray is advertised as 96KHz 24bit if there's no bits with AAC
[20:55] <JEEB> because blu-ray tends to have lossless formats in there?
[20:55] <Compn> dont tell him secrets
[20:55] <JEEB> and that sounds like the maximums of sort
[20:55] <JEEB> lol
[20:56] <Compn> Samus_Aran : the answer is marketers are liars
[20:56] <Samus_Aran> I thought most Blu-Ray discs used AVC+AAC, I guess I was mistaken
[20:56] <JEEB> lol
[20:56] <JEEB> I'm not sure if AAC is even in the specification :P
[20:56] <JEEB> there are some lossy formats in the spec as far as I can remember
[20:57] <JEEB> but generally DTS/AC3 if I recall correctly
[20:57] <JEEB> anyways, those are probably raw PCM maximum "specs" :P
[20:57] Action: LithosLaptop wonders if there has been somebody yet to hear a difference between 44.1KHz 16 bit and 96KHz 24bit audio
[20:57] <LithosLaptop> :)
[20:58] <LithosLaptop> they put 96KHz 24bit on Blu-Ray, because 'why not'. not because it is audibly better
[20:58] <JEEB> yup
[20:59] <JEEB> and since most stuff is created as 48kHz, 16bit, that's what most discs have in one way or another
[20:59] <Samus_Aran> if this was for my own usage, I would be using uncompressed PCM, but I'm trying to oversample the audio as much as possible for when YouTube murders it
[21:00] <Samus_Aran> uploading greater than 1080p video, or very high bitrate 1080p, seems to help the audio a lot
[21:01] <LithosLaptop> yeah because for 1080p Youtube uses a higher bitrate for the audio
[21:01] <Samus_Aran> the source is AC3 audio, which I can't use in the .mp4 for YouTube, so it's getting re-encoded multiple times.
[21:02] <Samus_Aran> so trying to preserve as much of the quality during this ugliness
[21:02] <LithosLaptop> uncompress it to PCM 16bit, 48Khz and mux that in a AVI container
[21:03] <LithosLaptop> then upload the AVI
[21:03] <Samus_Aran> I didn't think h.264 in AVI was very standard?  if YouTube accepts that, sounds like a plan
[21:03] <LithosLaptop> when I tried I couldn't get Youtube PCM in MKV container
[21:04] <LithosLaptop> only AVI seemed to work
[21:04] <LithosLaptop> but you might have better success
[21:04] <Samus_Aran> I can't believe how crappy mp4 containers are, they can barely handle any formats.  PCM is pretty basic.
[21:08] <Samus_Aran> it would be nice if YouTube supported all the open formats like MKV, FLAC, Ogg, Opus, Vorbis, etc.
[21:09] <LithosLaptop> I see FLV supports LPCM, so maybe you can try to mux the PCM and H.264 in a FLV and upload that to Youtube
[21:10] <LithosLaptop> ,but I am not sure what container formats Youtube will accept
[21:11] <LithosLaptop> Youtube does support uploading Vorbis btw
[21:12] <LithosLaptop> Iv'e done it before as long as it is in a webm container
[21:14] <Samus_Aran> I was noticing VP8 and Vorbis in webm.  does webm support h.264 video?
[21:15] <Samus_Aran> anyhow, thanks for the tips, lots to try out now.  :)
[21:15] <Samus_Aran> hopefully I can save one re-encode
[21:18] <LithosLaptop> does webm support h.264 video? <--- nope. only VP8 and Vorbis. In the *near* future it will support VP9 and Opus
[21:18] <LithosLaptop> no prob
[21:26] <ubitux> near?
[21:26] <ubitux> you can already
[21:43] <AnywhereIs> it seems like a trivial question but i can't cut a section out of my video. like, i need 154 seconds of it beginning from 30 second of input file. it goes well but on the output i get a video half-broken, causing lags and mplayer producing the following errors: http://dpaste.com/1467508/
[21:43] <AnywhereIs> the command i use is ffmpeg -ss 00:00:30 -t 00:02:34 -i DSC_0217.mkv -acodec copy -vcodec copy -y DSC_0217_cutn.mkv
[21:44] <sarthor> ffmpeg -i Lecture-4-Day3.avi -acodec libfaac -b:a 128k -vcodec mpeg4 -b:v 1200k -flags +aic+mv4 Lecture-4-Day3.mp4 not working for me.
[21:44] <sarthor>  Unknown encoder 'libfaac'
[21:46] <AnywhereIs> i hope it doesn't mean i have to re-encode the entire file to simply cut a few seconds here and there?
[21:49] <LithosLaptop> sarthor: you don't have your ffmpeg configured correctly to use libfaac
[21:49] <Samus_Aran> AnywhereIs: it should work with ffmpeg.  are there any errors output?  another option is to try mkvtoolnix and see if mkvmerge has the same issue
[21:50] <Samus_Aran> AnywhereIs: are you using a recently compiled ffmpeg?
[21:50] <Samus_Aran> or your distro's version?  which distro, which version of ffmpeg?
[21:50] <AnywhereIs> Samus_Aran: ffmpeg does not produce any errors while doing it. i'm not sure if it's recent though. gentoo.
[21:50] <AnywhereIs> i'll try building a newer one
[21:50] <sarthor> LithosLaptop: How to configure ffmpeg for flibfaac?
[21:51] <Samus_Aran> I was told there are improvements in the cutting of video segments in the more recent versions, so it would be worth try
[21:51] <Samus_Aran> *trying
[21:51] <LithosLaptop> sarthor: I am not sure. I always use precompiled ffmpeg win32 binaries :)
[21:51] <AnywhereIs> Samus_Aran: it's 1.0.5   built on Mar 28 2013 21:56:28
[21:51] <LithosLaptop> sarthor: but libfaac is a really bad AAC encoder anyway, check if libmp3lame works
[21:52] <Samus_Aran> AnywhereIs: definitely worth updating
[21:52] <AnywhereIs> Samus_Aran: are CLI options the same?
[21:52] <Samus_Aran> AnywhereIs: yes
[21:52] <AnywhereIs> i'll give it a shot
[21:53] <Samus_Aran> ffmpeg has pretty active development, so 8 months can make a difference.  :)
[21:53] <LithosLaptop> AnywhereIs: try using .ts output instead of .mkv and see if you also get the same errors. not sure what codecs your source has though; might be incompatible with .ts
[21:54] <AnywhereIs> it was x264 dual-pass from h264 huge raw from camera
[21:54] <Samus_Aran> the latest version from git is recommended.  not sure if that's what Gentoo uses automatically
[21:55] <AnywhereIs> costed hell lot of a time to reencode it (so as to shrink)
[22:00] <AnywhereIs> m, converting to .ts worked but i lost sound (flac)
[22:01] <AnywhereIs> i used ffmpeg -i DSC_0217.mkv -c copy -bsf h264_mp4toannexb 1.ts
[22:02] <AnywhereIs> and then cut on 1.ts and then again to mkv. vid was ok but sound was lost
[22:02] <Samus_Aran> you could use -codec:a pcm_s16le
[22:02] <Samus_Aran> to losslessly dump the flac to pcm
[22:02] <AnywhereIs> it will be stored in .ts right?
[22:03] <Samus_Aran> yes.  I'm not sure what the final goal is, but that wouldn't lose any quality
[22:03] <AnywhereIs> heh, now the cutting does not work
[22:04] <AnywhereIs> ffmpeg -i DSC_0217.mkv -c copy -bsf h264_mp4toannexb -codec:a pcm_s16le 1.ts
[22:04] <AnywhereIs> works okay
[22:04] <AnywhereIs> um, but mplayer 1.ts does not play any audio as well
[22:05] <AnywhereIs> from 1.ts
[22:05] <LithosLaptop> hmmm
[22:05] <Samus_Aran> I've only used .ts files to convert to other formats
[22:05] <Samus_Aran> don't know much about it
[22:05] <AnywhereIs> yeah, i know that, i'm just testing if it's there
[22:05] <AnywhereIs> and it appears it isnt
[22:05] <Samus_Aran> ffprobe file.ts
[22:06] <Samus_Aran> does it list both tracks?  audio/video
[22:06] <AnywhereIs> writes me loads of errors about ... AAC?
[22:06] <AnywhereIs> (the input file DSC_0217.mkv is x264 and flac)
[22:07] <Samus_Aran> I'm not sure why it would be using AAC if it was FLAC -> PCM
[22:07] <AnywhereIs> ffprobe: something like this http://dpaste.com/1467549/
[22:07] <Samus_Aran> were you able to get a more recent ffmpeg compiled?
[22:07] <AnywhereIs> is it something wrong with my command?
[22:07] <AnywhereIs> not yet, i was thinking i might work this out with .ts
[22:08] <AnywhereIs> > ffmpeg -i DSC_0217.mkv -c copy -bsf h264_mp4toannexb -codec:a pcm_s16le 1.ts # is the one i used and it produced no errors
[22:08] <Samus_Aran> AnywhereIs: even the output suggests you update your ffmpeg to the latest git version.  :p
[22:08] <AnywhereIs> yea
[22:08] <AnywhereIs> but output suggests audio is there  Stream #0:1 -> #0:1 (flac -> pcm_s16le)
[22:09] <AnywhereIs> video:165590kB audio:36318kB subtitle:0 global headers:0kB muxing overhead 8.313068%
[22:09] <AnywhereIs> on the other side ffprobe tells me     Stream #0:1[0x101](eng): Audio: aac ([6][0][0][0] / 0x0006), 12 channels (FL+FR+FC), s16, 187 kb/s
[22:10] <AnywhereIs> i hope it eventually works with newer one but it costed me hours to compress the video
[22:10] <Samus_Aran> maybe .ts doesn't take PCM
[22:11] <Samus_Aran> you won't lose your video
[22:11] <AnywhereIs> yep i just may have to rebuild it
[22:11] <Samus_Aran> just update to the latest and you should be able to remux it fine
[22:12] <Samus_Aran> if that doesn't work, try mkvmerge
[22:15] <AnywhereIs> lol. surprisingly enough it seemd to had work lol
[22:15] <AnywhereIs> never would have thought it will.
[22:15] <AnywhereIs> usually software updates just fail me
[22:18] <AnywhereIs> thanks for advices Samus_Aran LithosLaptop
[22:40] <Samus_Aran> AnywhereIs: glad it's working
[22:40] <Samus_Aran> I just noticed that my updated ffmpeg is having problems cutting segments from a .ts to an .mkv
[22:40] <Samus_Aran> it worked with the static ffmpeg I downloaded, but not with the git I compiled
[22:41] <Samus_Aran> [matroska @ 0x35ad260] Can't write packet with unknown timestamp av_interleaved_write_frame(): Invalid argument
[22:41] <AnywhereIs> i used non-git version
[22:41] <AnywhereIs> it's 1.2.4
[22:41] <AnywhereIs> but i didnt test it with .ts
[22:41] <AnywhereIs> it just worked out with mkv to mkv
[22:44] <Samus_Aran> I think there is a problem with today's and yesterday's git, as the static builds are incomplete (0 bytes)
[22:45] <Samus_Aran> I followed my own advice and now I can't cut mkv.  :p
[22:48] <AnywhereIs> that's what you get when updating, especially to unstable repos
[22:52] <AnywhereIs> Samus_Aran: CC0/WTFPL what i've just been working on (yt recodes it and it's not yet finished in HQ), https://www.youtube.com/watch?v=_KPNYX6kpEY  and a channel about nothing in particular lol.
[23:02] <Samus_Aran> AnywhereIs: nice shot.  I expected Nessie (Loch Ness creature) to surface.  :p
[23:02] <AnywhereIs> :>
[23:03] <Samus_Aran> reminds me of the song "smoke on the water"
[23:03] <AnywhereIs> it was just a morning after a night of meteor rain in august, i came down to a lake and saw this awesome fog, couldn't resist shooting it
[23:04] <Samus_Aran> it made me miss swimming and playing in a tidal slough as a kid
[23:05] <Samus_Aran> high tide you could swim, low tide was huge mud flats.  fun as a kid.  :)
[23:49] <Samus_Aran> muxing mkv is broken in the latest git.  the 2.0.x static release works fine
[23:50] <Samus_Aran> but my git compile is broken, and the static git compile from 2 days ago is also affected.
[23:54] <klaxa> f-file a bugreport?
[23:54] <pyBlob> Hello =)
[23:55] <pyBlob> I'm trying to specify a video filter on command line, how can I convert a yuv-stream to an rgb-stream, so I can apply a blend-filter on the rgb-stream?
[23:56] <Samus_Aran> klaxa: m-maybe l-l-later.        too busy atm.
[00:00] --- Sun Nov 17 2013


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