[Ffmpeg-devel-irc] ffmpeg.log.20140315

burek burek021 at gmail.com
Sun Mar 16 02:05:01 CET 2014


[00:03] <llogan> relaxed: damn it, you made me procrastinate again.
[00:04] Action: llogan goes back to boring, paid work
[00:05] <JEEB> at least you have one ;)
[00:07] <relaxed> you're no longer the "unfortunately i've been neglecting that particular guide lately" guy.
[00:07] <relaxed> ...and now I have a wiki account. I see what you did there.
[00:08] <llogan> there's still the PATH goofiness. ~/.bash_profile was from me being lazy, but it, as users oft say "doesn't work" for everyone
[00:09] <llogan> but i don't want to throw it into /usr/local because some users didn't have su powers but still have enough deps to compile, etc, IIRCAFAIK.
[00:11] <llogan> relaxed: did trac bitch to you about spam?
[00:11] <llogan> during registration
[00:11] <relaxed> a little bit
[00:12] <relaxed> /usr/local prefix is bad, in my opinion
[00:12] <relaxed> I'll look at the $PATH stuff later
[00:13] <llogan> yes, i also want to avoid it. especially on Debian and spawn since of conflicting packages in repo.
[00:14] <llogan> and deps that expect certain shit. although for just the binary i don't know how many dependent packages use that (KDenlive) now how they use it (via PATH or full path).
[00:14] <llogan> s/now/nor
[00:15] <llogan> i add the ~/.manpath to CentOS guide later too
[01:34] <gueb> hello
[02:11] <ItsMeLenny> ohaiguyz, i need a little help here, i'm trying to replace the audio stream in a video with an audio file, but the command line i have so far is just adding an extra audio stream
[02:11] <ItsMeLenny> -i ./MVI_2936.MOV -i ./MVI_2936_audio.flac -map 0 -map 1 -c:v libx264 -s 640x480 -aspect 16:9 ./Output.mov
[02:12] <ItsMeLenny> http://pastie.org/8920449
[02:13] <klaxa> that's neither the complete command, nor the console log
[02:13] <ItsMeLenny> oh right
[02:14] <ItsMeLenny> http://pastie.org/8920453
[02:14] <llogan> what's avconv?
[02:14] <ItsMeLenny> ffmpeg fork
[02:14] <llogan> try #libav
[02:14] <ItsMeLenny> it's the same command
[02:14] <sacarasc> But different programmes.
[02:15] <ItsMeLenny> theres nobody ever talking in libav
[02:15] <llogan> forks and third party products are not supported here
[02:15] <ItsMeLenny> and thats why i didnt paste that start of it in the first place
[02:15] <ItsMeLenny> i'm not asking for support
[02:15] <llogan> or use ffmpeg
[02:16] <ItsMeLenny> ok, i am using ffmpeg now, the exact same question still remains
[02:17] <sacarasc> ItsMeLenny: I think it is, and I suck at map, so who knows... -map 0.0:0.0 -map 1.0:0.1
[02:17] <klaxa> i'd rather go with -map 0:v -map 1:a
[02:17] <ItsMeLenny> llogan, paste bin for what? i am asking what the command is to replace an audio in a video with a different audio file
[02:17] <klaxa> map the video of the first input, the audio of the second input
[02:17] <klaxa> and maybe copy codecs, re-encoding seems pointless
[02:17] <llogan> ItsMeLenny: your fake ffmpeg that you're probably using is not supported here.
[02:18] <ItsMeLenny> lol, thanks sacarasc
[02:18] <ItsMeLenny> i went with klaxa 's, it worked like a charm, thanks very much
[02:19] <klaxa> ItsMeLenny: do consider switching to ffmpeg though
[02:20] <llogan> or next time ask in the empty, echoing halls of #libav is you want to continue using that
[02:20] <ItsMeLenny> klaxa, yeah i grab the nightly binaries usually, but avconv is in ubuntu by default, also theres some things which avconv does that ffmpeg doesnt and vice versa
[02:21] <klaxa> i haven't heard many good things about avconv, i compile ff-- oh well...
[02:21] <klaxa> this may be generalizing, but damn those ubuntu folks
[02:22] <llogan> s/those folks/a particular maintainer
[02:22] <klaxa> well apparently the usebase doesn't care enough either
[02:22] <klaxa> *userbase
[02:25] <mmint> The userbase probably just doesn't know
[02:26] <mmint> I (debian user) didn't know the story for almost a year
[02:26] <klaxa> at least this particular user knows, but refuses th coorperate
[02:26] <klaxa> *to
[02:27] <klaxa> i run debian on my servers too, at some point the ffmpeg binary said it was deprecated, so i asked, was pointed to the stackoverflow comment and started compiling ffmpeg from source
[05:32] <gueb> good night
[14:40] <sinhayash_> Hello everybody!
[14:40] <sinhayash_> I am new to ffmpeg.
[14:41] <sinhayash_> I am trying to convert an array of png images to video using ffmpeg in javascript in firefox browser
[14:41] <sinhayash_> What command do I need to call to achieve this?
[14:41] <sinhayash_> I am trying with a web worker.
[14:56] <klaxa> sinhayash_, i don't think you can do that in javascript with ffmpeg
[15:01] <sinhayash_> klaxa https://www.webrtc-experiment.com/ffmpeg/merging-wav-and-webm-into-mp4.html
[15:01] <sinhayash_> https://github.com/bgrins/videoconverter.js
[15:05] <sinhayash_> klaxa: Is there something I am missing out?
[16:19] <eth2wlan> Hi
[16:19] <eth2wlan> I have a question
[16:19] <eth2wlan> (of course)
[16:19] <jarainf> We all do~
[16:19] <eth2wlan> ok, I'm going to explain
[16:20] <eth2wlan> I've a 720p «H264 - MPEG-4 AVC (part 10) (H264)»
[16:20] <eth2wlan> (this is what VLC says)
[16:21] <jarainf> eth2wlan, please post the ffprobe output :3
[16:21] <eth2wlan> yes
[16:21] <eth2wlan> ("please hold the line")
[16:22] <eth2wlan> 1) Duration: 00:01:59.86, start: 0.000000, bitrate: 1953 kb/s
[16:23] <eth2wlan> 2) Stream #0:0: Video: h264 (Baseline) (H264 / 0x34363248), yuv420p, 1280x720, 600 fps, 600 tbr, 600 tbn, 1200 tbc
[16:23] <eth2wlan> This is what ffprobe says
[16:23] <eth2wlan> Ok
[16:23] <jarainf> eth2wlan, so what are you trying to do?
[16:24] <eth2wlan> jarainf, justo to improve compression with as-high-as-possible quality
[16:25] <eth2wlan> Al my attempt results in an bigger and/or worse video file
[16:25] <klaxa|web> eth2wlan: see: https://trac.ffmpeg.org/wiki/x264EncodingGuide
[16:26] <eth2wlan> Note: it is a fixed videocamera video file. For a long time, nothing change in the picture.
[16:26] <klaxa|web> well what have you tried so far? the encoding guide should be comprehensive enough for a novice to encode to sufficient quality
[16:27] <eth2wlan> Last but not least: the ffmpeg job must be faster than the movie duration
[16:27] <klaxa|web> that may or may not be possible
[16:27] <klaxa|web> what hardware are you encoding on?
[16:27] <eth2wlan> For example, for a 60 minutes video, ffmpej must recompress it in less than 60 minutes
[16:28] <klaxa|web> i'll ask again, what hardware are you encoding on?
[16:28] <eth2wlan> The hardware is an old Acer Extensa 5220
[16:29] <eth2wlan> Googling, it is a Celeron M 530 @ 1.74GHz
[16:30] <klaxa|web> i highly doubt you will be able to encode with a sufficient quality, faster than real-time on that hardware
[16:30] <eth2wlan> Yes, I'm afraid that is not possible to
[16:31] <eth2wlan> So, this is the real question
[16:32] <eth2wlan> ("it is possible to compress faster than movie lenght with sufficient quality")
[16:33] <jarainf> that was a statement.
[16:33] <klaxa|web> apart from that: short answer for your specific usecase: probably not
[16:34] <klaxa|web> there is too little information about the video content (not even the encoding and measuered "quality", but perceived complexity) and your hardware is old and weak
[16:37] <eth2wlan> Ok, probably I can't have what I need. I just asked here before of deepen (and waste of time, if is not possible) in the documentation
[16:38] <eth2wlan> Thank you very much
[16:40] <eth2wlan> Sorry, I've forgotten an important thing.
[16:40] <eth2wlan> The greetings. :-)
[16:40] <eth2wlan> Bye!
[21:03] <sajjadg> How can I detect the audio codec/format inside a container (mkv) and extract is without encoding (copy) to another container(e.g. mka)?
[21:06] <sajjadg> avconv -i part2.mkv -acodec copy part2.mka works
[21:06] <sajjadg> but but ogg doesn't!
[21:07] <sacarasc> #libav is the channel for avconv. It could be an avconv bug.
[21:07] <sacarasc> (Also, ogg supports video.)
[21:07] <sacarasc> Try -an
[21:07] <sajjadg> Stream #0.1: Audio: vorbis, 48000 Hz, stereo, fltp (default)
[21:07] <sajjadg> I'm the enemy now :P
[21:22] <wodim> hello, what would you say are the most safe audio and video codecs you think are supported by all home dvd players?
[21:24] <sacarasc> MPEG2 and AC3.
[21:24] <wodim> alright, let's see
[21:24] <wodim> and what container?
[21:24] <wodim> avi?
[21:24] <sacarasc> No, make an actual DVD.
[21:25] <wodim> it's for a home dvd player with a usb socket
[21:25] <wodim> so it has to be a file
[21:25] <wodim> i guess an avi is ok
[21:25] <sacarasc> You said ALL home DVD players.
[21:25] <wodim> heh, well... my fault
[21:25] <sacarasc> My DVD player can't do anything except actual DVDs. :p
[21:25] <wodim> do you change your mind now that you have this new information? :p
[21:26] <sacarasc> You could look up what your DVD player can do, but you probably want MPEG4 ASP and MP3 in AVI, then.
[21:26] <wodim> ok, let's see
[21:39] <relaxed> wodim: you'll need -vtag XVID if you're using ffmpeg's mpeg4 encoder.
[21:39] <wodim> alright alright
[21:40] <wodim> -acodec libmp3lame -vcodec mpeg4
[21:40] <wodim> how right does this sound?
[21:43] <relaxed> ffmpeg -i input -c:v mpeg4 -q:v 3 -vtag XVID -c:a libmp3lame -b:a 192k -ac 2 output.avi
[21:44] <wodim> ok.
[21:44] <wodim> but the size of the new movie is worrying me.
[21:45] <wodim> is it because this codec is shit?
[21:45] <sacarasc> Do you want it to be a specific size?
[21:45] <wodim> i would like it to look good
[21:46] <wodim> but it's like 200MB for 10 minutes
[21:46] <wodim> while the original file is 650MB for 1h30 and looks perfectly
[21:46] <wodim> haha
[21:46] <sacarasc> 650MB for 90 minutes will not look perfect. :(
[21:46] <wodim> yes, you're right
[21:47] <wodim> let's say "very good"
[21:47] <sacarasc> What is the original file?
[21:47] <wodim> "h264 mpeg-4 avc"
[21:47] <wodim> if that says something to you
[21:48] <sacarasc> Yeah, AVC is a LOT better at compression than ASP.
[21:49] <wodim> 500MB for 18 minutes
[21:49] <wodim> haha
[21:49] <wodim> god
[21:49] <wodim> i think this dvd player won't be able to read that much of the USB drive at once
[21:49] <wodim> it will jam
[21:49] <relaxed> use 2 pass encoding if you need a specific size
[21:49] <wodim> i will see if the player can do this
[21:50] <relaxed> https://trac.ffmpeg.org/wiki/x264EncodingGuide
[21:50] <wodim> no, i'm not recoding in h264, but mpeg4
[21:50] <relaxed> look at the "Two-Pass" section and apply that to your mpeg4 ecndoing command
[21:50] <wodim> ah
[21:50] <relaxed> encoding*
[21:54] <wodim> can subtitles be embedded in avi files?
[21:55] <wodim> alright, with mpeg4 i get audio but no sound
[21:55] <wodim> uh
[21:56] <wodim> oops
[21:56] <wodim> audio but no video
[21:56] <wodim> heh
[21:57] <relaxed> try -vtag DIVX
[22:14] <wodim> can ffmpeg take advantage of multicore systems?
[22:27] <klaxa> depends on the codec, usually yes
[22:27] <klaxa> as far as i know at least
[00:00] --- Sun Mar 16 2014


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