[Ffmpeg-devel-irc] ffmpeg.log.20160717

[burek]

[00:24:21 CEST] <Visual-Vincent> I would like to speak to a moderator about a FFmpeg license question.
[00:27:32 CEST] <__jack__> you may ask
[00:27:48 CEST] <__jack__> dunno if someone here will be able to help you
[00:29:03 CEST] <Visual-Vincent> @__jack__ : Thank you, but I would rather speak to a moderator or someone who has knowledge in FFmpeg's license.
[00:29:55 CEST] <__jack__> you won't ask in public, is that it ?
[00:30:31 CEST] <__jack__> you can ask michael at niedermayer.cc by email, still dunno if he can help you
[00:30:59 CEST] <Visual-Vincent> Don't know if I really care about talking in public/private, though I just felt like talking alone with someone.
[00:31:02 CEST] <Visual-Vincent> Thank you.
[06:28:24 CEST] <soulshock> curious. ffmpeg -i test.mov -filter_complex "yadif=0:-1:0,scale=1280:720,format=yuv420p" -c:v libx264 -profile:v high -level 4.1 -refs 4 -pass 1 -f mp4 -fastfirstpass 1 -c:a libfdk_aac /dev/null produces "[libx264 @ 0x266dd60] profile Main, level 4.1" and when I run -pass 2 it uses profile High
[06:47:23 CEST] <blb> soulshock: you said high profile though?
[06:48:04 CEST] <soulshock> yeah I used -profile:v high in the 1st pass
[06:48:24 CEST] <soulshock> I would expect it to use high profile in both passes
[06:53:28 CEST] <soulshock> unless, of course, profile doesn't matter when doing 1st pass
[14:01:56 CEST] <AL13N_lappy> i have some aspect ratio trouble
[14:02:59 CEST] <AL13N_lappy> there's a smaller device that plays movies, so i tried to convert it to the native resolution and tried to make it use as much screen as possible, but i still got black borders in some places
[14:03:42 CEST] <AL13N_lappy> device is resolution: 480x234 but display size is 15.4cm x 8.6cm (7" screen)
[14:04:37 CEST] <AL13N_lappy> a movie that has 296x234 resolutions, has no black borders; while a movie that has 339x234 has horizonal black borders above and below
[14:05:04 CEST] <AL13N_lappy> i tried to look with ffmpeg -i into those files, but i noted also SAR and DAR mentions
[14:05:40 CEST] <AL13N_lappy> how can i convert a movie into the native resolution without having black borders (even if i crop the movie)
[14:05:44 CEST] <AL13N_lappy> there's some strange math here
[14:07:32 CEST] <BtbN> scale to the appropiate width/height, and then crop the one that's larger to fit the screen.
[14:08:37 CEST] <furq> AL13N: https://ffmpeg.org/ffmpeg-filters.html#setdar_002c-setsar
[14:32:24 CEST] <AL13N> BtbN: furq: it's just that on resolutions i get, but it seems there's more to resolutions than just pixel widths... i'm missing something
[14:32:37 CEST] <AL13N> as to why a 394x234 movie on a device with 480x234 gives black borders above and below(instead of left and right); and a 296x234 movie has no black borders whatsoever
[14:33:46 CEST] <AL13N> furq: this sar and dar, are they stored inside the movie metadata?
[14:34:04 CEST] <AL13N> is this something that the device uses to display the movie?
[14:37:16 CEST] <AL13N_lappy> this movie:  296x234 [SAR 104:73 DAR 1184:657] is shown fullscreen on the device (which is reported to have 480x234 pixels)
[14:38:12 CEST] <klaxa> interesting ratios
[14:38:30 CEST] <AL13N_lappy> but, i don't understand why it's shown fullscreen... the math doesn't seem to come close
[14:38:34 CEST] <AL13N_lappy> so i'm missing something
[14:38:48 CEST] <AL13N_lappy> klaxa: yes, indeed
[14:40:04 CEST] <AL13N_lappy> at the very least the SAR doesn't match the actual pixels ratio 296x234
[14:42:12 CEST] <AL13N> so, how does a movie actually gets displayed?
[14:42:57 CEST] <AL13N> does it take the pixels and applies a SAR on it first? and then depending on the display, it rescales and uses the DAR on that once more?
[14:44:21 CEST] <AL13N> or does SAR mean that the movie needs to be interpreted as 104:73 (even though it's resolution is 196x234)?
[14:45:26 CEST] <AL13N> or was the original movie just broken with wrong aspect ratios?
[15:04:34 CEST] <DHE> SAR (sample aspect ratio) is the aspect ratio of the pixels, not the whole image
[15:04:52 CEST] <DHE> so 1:1 on a 1920x1080 encoding will produce 1920x1080 output
[15:09:35 CEST] <anddam> -map_metadata at http://ffmpeg.org/ffmpeg.html#Advanced-options has reference to chapters, but I wasn't able to find a description of what "chapters" are in ffmpeg in man page, wiki or documentation
[15:10:07 CEST] <anddam> namely i have a MPEG4 container with an AAC audio stream and i'd like to arbitrarily add chapters to use it in itunes as audiobook
[15:11:05 CEST] <anddam> also, out of curiosity, why does ffprobe output in stderr rather than stdout? every time I pipe the output with a pager I notice this and I've always been confused by it
[15:14:29 CEST] <__jack__> anddam: ffprobe output to stdout
[15:14:45 CEST] <__jack__> stderr is the random generic output, stdout it what you asked for
[15:15:03 CEST] <__jack__> try ffprobe -show_stream -print_format json truc.mkv 2>/dev/null
[15:15:08 CEST] <anddam> "random"?
[15:15:29 CEST] <anddam> > ffprobe 01\ The\ Hobbit.m4b ^/dev/null | wc -l
[15:15:31 CEST] <anddam>        0
[15:15:49 CEST] <anddam> ^ is fd 2 in fish shell
[15:16:03 CEST] <__jack__> yep, you didn't ask for any information, so you get none
[15:16:14 CEST] <__jack__> (random as non-scriptable creapy format, human-only)
[15:16:26 CEST] <anddam> oh I see, the generic part now, I didn't know I had to query for something
[15:16:40 CEST] <anddam> I've always used the default output
[15:16:46 CEST] <anddam> s/see, /see /
[15:18:34 CEST] <anddam> at least it makes sense
[15:18:38 CEST] <anddam> good
[15:19:10 CEST] <anddam> __jack__: do you possibly have any hint about the chapters thing as well?
[15:43:19 CEST] <Sonmi> hi. im trying to get deinterlaced 60fps A/V capture from a dazzle DVC100. right now i can only get 30p and no audio, anybody know about this? thanks
[15:43:42 CEST] <AL13N> DHE: so if i have a 296x234 pixels and it's SAR 1:1 and DAR 1:1 then a display of 480x234 will show 296x234 ?
[15:44:19 CEST] <AL13N> DHE: so if i have a 296x234 pixels and it's SAR 2:1 and DAR 1:1 then a display of 480x234 will show 148x234 ?
[15:44:32 CEST] <AL13N> or 592x234 ?
[15:45:36 CEST] <AL13N> DHE: so if i have a 296x234 pixels and it's SAR 1:1 and DAR 2:1 then a display of 480x234 will show 148x234 ?
[15:46:05 CEST] <AL13N> i assume having SAR=2:1 and DAR 2:1 they would cancel each other out then?
[15:47:16 CEST] <AL13N> what about the device that plays it... it has 480x234 output pixels, but the display size is 15.4cm x 8.6cm
[15:47:32 CEST] <AL13N> would it use the actual cm to scale? or the resolution?
[15:59:05 CEST] <__jack__> anddam: ffprobe -show_chapters
[16:02:36 CEST] <AL13N_lappy> DHE: furq: BtbN: i'm calculating; but i'm not getting it... :-(
[16:03:05 CEST] <AL13N_lappy> the device must've done something odd
[16:12:25 CEST] <anddam> __jack__: but that won't help me adding chapters to a MPEG4
[16:13:15 CEST] <__jack__> huh ok, was still on the ffprobe stuff
[16:13:26 CEST] <__jack__> I dunno how to create chapter with ffmpeg
[16:49:48 CEST] <klaxa> anddam: i used chapters for matroska files, not sure if it works with mp4, but i can dig around my old code
[16:50:44 CEST] <klaxa> anddam: https://www.ffmpeg.org/ffmpeg-formats.html#Metadata-1 this section also describes the syntax for chapters
[17:02:23 CEST] <anddam> klaxa: thanks
[20:20:13 CEST] <jonathan_x> Is there a way to create an easy audio fadeout at the point where I want to cut off a video (maybe video fadeout as well).
[22:52:03 CEST] <maziar> why when i use this command i get this error : http://pastebin.com/xADyk776
[22:52:44 CEST] <furq> [libx264 @ 0x23717e0] width not divisible by 2 (1365x720)
[22:52:55 CEST] <furq> -vf scale=-2:720
[22:54:05 CEST] <maziar> furq let me test it
[22:57:17 CEST] <Karolis> hello, can someone explain me why native frame rate grabber (-re) with concat filter isn't working correct? http://pastebin.com/B9a7umVZ
[23:48:27 CEST] <egnun> Hello #ffmpeg
[23:49:06 CEST] <__jack__> hi!
[23:49:10 CEST] <egnun> I want to compile ffmpeg, but I *only* want to include free codes. (so I *don't* want to compile it with proprietary codecs)
[23:49:20 CEST] <egnun> What options do I need to use?
[23:49:54 CEST] <egnun> Is this ok?
[23:49:54 CEST] <egnun> ./configure --prefix=/opt/ffmpeg --enable-gpl --enable-version3 --disable-nonfree
[23:50:20 CEST] <egnun> (Oh, and I downloaded the files directly from the git-repo)
[23:51:58 CEST] <__jack__> sound correct
[23:52:08 CEST] <JEEB> you're saying it in a weird way and things incompatible with (L)GPL are disabled by default. this does not of course disable the implementation of reverse engineered proprietary formats that are implemented in libavcodec
[23:52:38 CEST] <egnun> __jack__: Ok.
[23:53:11 CEST] <egnun> JEEB: I am asking, because the "--enable-nonfree" option confused me.
[23:53:52 CEST] <egnun> It said under "Standard options:"
[23:53:52 CEST] <egnun> "--enable-nonfree       allow use of nonfree code, the resulting libs and binaries will be unredistributable [no]"
[23:53:53 CEST] <JEEB> http://git.videolan.org/?p=ffmpeg.git;a=blob;f=configure;h=4956afc52cdbfe6ef0dff5e4491a040056d2cc08;hb=HEAD#l5039
[23:54:09 CEST] <JEEB> these are the only things, and they specifically require ENABLE-nonfree
[23:54:42 CEST] <furq> there isn't an option to disable everything patent-encumbered
[23:54:47 CEST] <__jack__> nope
[23:54:52 CEST] <__jack__> patent are not worldwide
[23:54:57 CEST] <__jack__> not always, at least
[23:54:58 CEST] <furq> nonfree just refers to licensing
[23:55:15 CEST] <egnun> furq: Ah, ok.
[23:55:20 CEST] <JEEB> for example fdk-aac is open source but not license compatible and thus requires nonfree. same for openssl
[23:56:09 CEST] <furq> i guess you want --disable-encoders --disable-decoders and then selectively enable the ones you want
[23:56:20 CEST] <egnun> furq: So, that's why mp3 and mp4 will also be compiled?
[23:56:28 CEST] <egnun> +e.g.
[23:56:29 CEST] <furq> right
[23:56:33 CEST] <egnun> Aye.
[23:56:40 CEST] <egnun> Damnit. I guess. ^^
[23:56:47 CEST] <furq> yeah it's a bit of a nuclear solution
[23:58:07 CEST] <egnun> Is there a difference between "--disable-encoders" and "--disable-decoders" patent wise?
[23:58:30 CEST] <JEEB> dunno, depends on how things are licensed I guess
[23:58:33 CEST] <furq> you're probably less likely to get sued for decoding something
[23:58:34 CEST] <__jack__> egnun: I guess that mp3 is free, on a licencing point of view
[23:58:44 CEST] <furq> but in theory, no
[23:58:54 CEST] <__jack__> (decoder: mp3, probably internal; encoder, libmp3lame, shared object)
[23:59:11 CEST] <furq> lame is either gpl or lgpl
[23:59:33 CEST] <JEEB> FFmpeg only touches on the open source SW licensing side, nothing else
[23:59:49 CEST] <egnun> Ok, thank you, guys!
[23:59:53 CEST] <JEEB> also FFmpeg officially provides only source code
[00:00:00 CEST] --- Mon Jul 18 2016