[Ffmpeg-devel-irc] ffmpeg.log.20160131

[burek]

[10:45:36 CET] <BlackBishop> any easy way to get one.mkv to two.mkv with same resolution but lower a/v bitrate ?
[10:48:58 CET] <BlackBishop> ( even keeping the codec )
[10:55:22 CET] <BlackBishop> ffmpeg -i sone.mkv -b:v 2048k ~/stwo.mkv would be enough ?
[10:56:23 CET] <BlackBishop> hmmm .. and -preset ultrafast
[14:03:47 CET] Action: cousin_luigi would like to concatenate and reencode to h265 two files of a different resolution: what is the best way to do so?
[14:42:16 CET] <waressearcher2> cousin_luigi: ffmpeg -i file1.mp4 -i file2.mp4 -filter_complex '[0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a]' -map '[v]' -map '[a]' -vcodec h264 -vb 2000k -vf scale=1280:720 -ab 128k -ar 44100 -ac 2 -acodec libmp3lame -y -f mp4 out.mp4
[14:43:42 CET] <cousin_luigi> waressearcher2: Won't that reencode to x264?
[14:43:46 CET] <cousin_luigi> But thanks.
[14:45:27 CET] <waressearcher2> cousin_luigi: ffmpeg -i file1.mp4 -i file2.mp4 -filter_complex '[0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a]' -map '[v]' -map '[a]' -vcodec h265 -vb 2000k -vf scale=1280:720 -ab 128k -ar 44100 -ac 2 -acodec libmp3lame -y -f mp4 out.mp4 ?
[14:46:04 CET] <cousin_luigi> Looks good. Thanks!
[14:46:06 CET] <cousin_luigi> bbl
[14:48:34 CET] <tp_> what technology is used for DTS hardware acceleration? i have an old Intel Q9400 CPU which is terrible for DTS decoding
[16:24:56 CET] <kepstin> hmm? DTS should decode fast enough that you don't even notice it on that processor
[16:25:51 CET] <kepstin> if you don't want to decode it on the cpu, you need an external decoder (e.g. a stereo receiver) that can take a dts bitstream over hdmi or spdif.
[16:27:24 CET] <tp_> i do, i need to transcode it, but a Q9400 is too slow for DTS
[16:31:12 CET] <kepstin> oh, you're encoding to dts?
[16:31:33 CET] <kepstin> or.. no, doesn't seem like it
[16:31:48 CET] <kepstin> it's *probably* something other than dts decoding that's slow for you
[16:39:43 CET] <tp_> im decoding DTS, and thats really slow on a Q9400 :/
[16:40:33 CET] <tp_> DTS>AAC is slow, but AC3>AAC is fast enough
[17:10:09 CET] <chungy> how slow are you talking?
[17:10:28 CET] <chungy> the encoder doesn't care what the input codec was
[17:10:44 CET] <chungy> Q9400 is a Core 2 isn't it? That should be plenty for DTS.
[17:18:53 CET] <dystopia> how can i download video from m3u8 files with the latest ffmpeg builds from zeranoe?
[17:19:06 CET] <dystopia> the commands that worked before faile in the latest builds
[17:19:48 CET] <J_Darnley> Failed with what message?
[17:20:07 CET] <J_Darnley> And ffmpeg is not really a tool for *downloading* files.
[17:20:34 CET] <dystopia> ffmpeg -i %m3u8link% -cookies %cookie% -vcodec copy download.mp4
[17:20:43 CET] <dystopia> well this worked for years, now it doesent heh
[17:21:04 CET] <dystopia> only thing ffmpeg says now is "data found processing input"
[17:21:07 CET] <J_Darnley> (For some definition of "work")
[17:21:16 CET] <dystopia> http://i.imgur.com/v9Opwwn.png
[17:21:47 CET] <dystopia> well i downloaded with ffmpeg then encoded them again with ffmpeg to x264
[17:22:48 CET] <chungy> they're already H.264 it seems
[17:22:56 CET] <dystopia> yeah they are
[17:23:22 CET] <chungy> Try putting -cookies before the input?
[17:23:34 CET] <dystopia> ok
[17:23:41 CET] <dystopia> will give it a shot
[17:49:51 CET] <andrey_utkin> could anybody please remind/explain why x264 complains for "broken settings" with ./doc/examples/transcoding? https://gist.github.com/andrey-utkin/c6fb55bb3e13faf82fbe
[17:50:00 CET] <andrey_utkin> what special ffmpeg cli util does to avoid this?
[17:50:46 CET] <Mavrik> Just how old is your ffmpeg??
[17:51:16 CET] <andrey_utkin> current git master HEAD
[17:53:31 CET] <JEEB> interesting, that check definitely shouldn't be hit by default, it was meant for the defaults that got changed around 2011
[17:53:42 CET] <JEEB> andrey_utkin: how old is your x264?
[17:54:44 CET] <JEEB> oh wait, examples
[17:54:49 CET] <JEEB> I wonder...
[17:56:25 CET] <JEEB> andrey_utkin: can you please iterate until you get it back to working with git bisect or so? :)
[17:56:31 CET] <JEEB> meanwhile I'll poke -devel
[17:58:34 CET] <andrey_utkin> x264 is something 148, hard to say - the package is x264-9999 :) https://gist.github.com/andrey-utkin/46757f7499eba4036336
[17:59:01 CET] <andrey_utkin> JEEB: ok
[18:00:48 CET] <andrey_utkin> sorry, seems ffmpeg used that time is 2.8.5, but still this is recent
[18:01:45 CET] <JEEB> 2.8.x was branched quite a bit of time ago
[18:02:13 CET] <andrey_utkin> rebuilding git master HEAD now just to be sure
[18:26:55 CET] <andrey_utkin> now with proper local rebuild with --enable-shared the situation is different: https://gist.github.com/andrey-utkin/d92df8e767dc853457b1
[18:27:50 CET] <andrey_utkin> AVCodec ff_libx264_encoder doesn't have pix_fmts[] set...
[18:29:06 CET] <andrey_utkin> should we add it (back)?
[18:29:35 CET] <JEEB> please try with a standard configure without any params
[18:29:45 CET] <andrey_utkin> ok
[18:29:49 CET] <JEEB> which is a static libs+binary
[18:30:16 CET] <andrey_utkin> JEEB: this way examples get linked with system-provided libs, which are in my case 2.8.5
[18:30:27 CET] <JEEB> uhh
[18:30:37 CET] <JEEB> don't mish-mash FFmpeg libraries :P
[18:30:45 CET] <andrey_utkin> i'm used to that
[18:30:54 CET] <JEEB> it would use mpeg-4 part 2 encoder for the mkv file I think. if that works, then --enable-gpl --enable-libx264
[18:31:06 CET] <JEEB> you might be used to it but it might bring out random weirdness as well :P
[18:31:43 CET] <andrey_utkin> JEEB: please look at my last paste, no encoders are involved except libx264
[18:32:02 CET] <JEEB> yes, but with a default no-configure-params build you won't have libx264
[18:32:17 CET] <JEEB> first you try with a standard LGPL build, then enable-gpl and enable-libx264
[18:32:21 CET] <JEEB> :P
[18:32:26 CET] <andrey_utkin> and I have already determined that the issue is that AVCodec definition doesn't have .pix_fmts part, so it remains NULL in contrary to many other codecs
[18:33:02 CET] <andrey_utkin> is there some API function to get codec's preferred pix_fmt? or should we bring back that definition?
[18:33:11 CET] <andrey_utkin> JEEB: i have enable-gpl in my configure
[18:33:19 CET] <JEEB> you definitely seem to not be listening
[18:33:20 CET] <JEEB> fine
[18:33:35 CET] <andrey_utkin> i can expose to you the fullest track of what i am doing
[18:33:44 CET] <andrey_utkin> JEEB: you seem the same to me :)
[18:34:22 CET] <JEEB> after you said that you have mish-mashed FFmpeg libraries it is a top priority that you can replicate things with a standard static build
[18:34:50 CET] <JEEB> because otherwise whatever is happening to you can be random and/or not really an issue. I cannot be sure, but I must limit the issue to whatever it is
[18:35:11 CET] <JEEB> which is why I asked you to try with a standard FFmpeg build + that example built
[18:35:13 CET] <andrey_utkin> well fine, going to create a sandbox to avoid disruption of my system
[18:35:18 CET] <JEEB> why!?
[18:35:25 CET] <JEEB> I mean, you have the code, right
[18:35:33 CET] <andrey_utkin> so?
[18:35:38 CET] <andrey_utkin> so what?
[18:35:40 CET] <JEEB> then you mkdir build && ../configure && make -jN
[18:35:47 CET] <JEEB> that will not affect your system in any way or form
[18:35:48 CET] <andrey_utkin> && make install
[18:35:55 CET] <JEEB> why would you install something you're just testing!?
[18:36:00 CET] <JEEB> it's static, too
[18:36:13 CET] <JEEB> you might use a custom prefix if the example requires a proper dir structure
[18:36:15 CET] <JEEB> (--prefix)
[18:36:23 CET] <JEEB> and then just point the example building to it
[18:36:23 CET] <andrey_utkin> because when examples are built, they have just -lstuff, no -L as far as i have seen
[18:36:37 CET] <andrey_utkin> so it gets linked with system-wide installed libs
[18:36:41 CET] <andrey_utkin> as i have said previously
[18:36:56 CET] <JEEB> well I see you already know how to do LDFLAGS (if those work)
[18:37:12 CET] <JEEB> just use a custom prefix if you really need to, no need to affect your whole system or setup complex chroots or anything
[18:37:31 CET] <JEEB> --prefix=/home/my_username/muh_ffmpeg or whatever
[18:38:24 CET] <andrey_utkin> JEEB: please look at doc/examples/Makefile and figure out that it uses system-wide installed libs and doesn't try to use ones from local sources tree
[18:39:05 CET] <JEEB> ok, it uses pkg-config. evne better
[18:39:19 CET] <JEEB> PKG_CONFIG_PATH=/home/my_username/muh_ffmpeg/lib/pkgconfig
[18:39:29 CET] <JEEB> before you run the makefile
[18:39:42 CET] <JEEB> https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/Makefile#L11
[18:40:18 CET] <andrey_utkin> that's right, i just explained that install phase is required
[18:40:34 CET] <JEEB> yes, and I have been saying that you can use a custom prefix for quite a while
[18:40:48 CET] <JEEB> 19:37 < JEEB> you might use a custom prefix if the example requires a proper dir structure
[18:40:51 CET] <JEEB> 19:37 < JEEB> (--prefix)
[18:40:52 CET] <JEEB> and then
[18:40:57 CET] <JEEB> 19:38 < JEEB> just use a custom prefix if you really need to, no need to affect your whole system or setup complex chroots or anything
[18:41:00 CET] <JEEB> 19:38 < JEEB> --prefix=/home/my_username/muh_ffmpeg or whatever
[18:41:01 CET] <andrey_utkin> no, you've been saying "why would you install something you're just testing!?" first
[18:41:18 CET] <JEEB> yes, I said that first because I wasn't sure at that point since I've never built the damn examples
[18:41:36 CET] <JEEB> but in any case, prefix can be set and as I said, that will not affect your goddman installed pakcages in any way or form
[18:42:15 CET] <JEEB> so can we just get this tested with? unless you're just picking me off on purpose to make me do the testing
[18:43:05 CET] <andrey_utkin> JEEB: i'll test it
[18:43:32 CET] <JEEB> I just want to make sure that whatever issue you're having also happens with a standard build without any of your "lol I mixed stuff and it doesn't work" shenanigans
[18:44:09 CET] <JEEB> first without libx264 (enable-gpl and enable-libx264, just an empty configure with the prefix)
[18:44:20 CET] <JEEB> and then with enable-gpl and enable-libx264 that adds libx264 there
[18:45:29 CET] <JEEB> and then if both of those work it's a more limited issue related to whatever you've been doing
[19:52:34 CET] <tp_> chungy: less than 30 fps encoding, and 100% cpu load while doing it, and yes, its a core 2 quad
[19:59:51 CET] <chungy> tp_: encoding isn't decoding, like you were talking about
[20:00:17 CET] <chungy> and fps doesn't really make sense in the context of audio... heh.
[20:05:44 CET] <kepstin> tp_: I assume you're doing audio-only encoding (e.g. an audio only source, with -vn to disable video, or -c:v copy)?
[20:29:58 CET] <tp_> well, audio needs to be decoded before it can be encoded i guess
[20:30:03 CET] <tp_> its with video copying, and it works fine with AC3>AAC
[20:32:08 CET] <tp_> it will take longer to transcode a DTS stream than listening to it
[20:36:42 CET] <tp_> i dont find anywhere where i said encoding is decoding tho
[22:08:14 CET] <spookypeanut> for those that were here for me talking about retiming dvd subtitles last night, I have a plan
[22:08:48 CET] <spookypeanut> i am going to use the info on this page: http://archive09.linux.com/feature/125978
[22:09:05 CET] <spookypeanut> all command line ways to rip, just only from vob
[22:09:37 CET] <spookypeanut> then it ocrs to an srt, so i'll write a tiny python script to retime that
[22:09:44 CET] <spookypeanut> thanks for al the suggestions!
[23:29:09 CET] <solrize> hi guys i sometimes have to convert a big mp4 file to webm preferably without having to wait too long.  i have a 4-core computer, is it reasonable to split the input file into 4 pieces, convert in parallel, then recombine?
[23:31:38 CET] <Mavrik> Nope.
[23:32:02 CET] <Mavrik> VP9 encoder should be able to use all four cores.
[23:32:11 CET] <Mavrik> Which makes splitting files just a waste of time.
[23:39:43 CET] <J_Darnley> how old fashioned
[23:39:56 CET] <J_Darnley> I feel a /. joke coming.
[23:41:01 CET] <Mavrik> O.o
[23:41:02 CET] <durandal_170> buy better CPU, or do smthg else
[23:42:40 CET] <drv> does ffmpeg run on beowulf clusters? :)
[00:00:00 CET] --- Mon Feb  1 2016