[Ffmpeg-devel-irc] ffmpeg.log.20120218

burek burek021 at gmail.com
Sun Feb 19 02:05:02 CET 2012


[00:34] <pasteeater> why do you want shared and pic?
[01:08] <Austen> should I not?
[01:28] <pasteeater> it can make compilation trickier, and you probably don't it, but i'm not sure what you're doing exactly
[01:30] <Austen> so, i attempted to build almost all the libraries with disable-shared, but have ffmpeg build with --enable-shared
[01:31] <Austen> with fPIC in my CFLAGS, and that caused the shared libraries to fail during make
[01:31] <Austen> i was looking at it more, it appears theres not that much of a benifit to having enable-shared; a bigger binary but the libraries have to be there in either case....
[01:32] <Diogo> hi, one question please, first this is possible use ffmpeg for real time encoding, i need to build a file upload in php (send file via POST http) and the server when is getting the video start to encode..any tutorial on the web? like transloadit..
[01:34] <Diogo> i can see a solution http://transloadit.com/demos/video-encode/encode-a-video-in-realtime
[01:35] <Diogo> but i don't know how they do this..
[01:35] <Diogo> thanks for your help
[03:50] <const_antine> hello
[03:50] <const_antine> here's a confusing quote from faq
[03:50] <const_antine> "Both Xvid and DivX (version 4+) are implementations of the ISO MPEG-4 standard (note that there are many other coding formats that use this same standard). Thus, use ’-c:v mpeg4’ to encode in these formats."
[03:51] <const_antine> isn't mpeg-4 format for media container files?
[03:51] <const_antine> and not media itself?
[03:56] <const_antine> nvm, wrong
[04:18] <entreri> hello, it is possible to take a picture from the command-line using ffmpeg ?
[04:20] <Tjoppen> what kind of picture?
[04:20] <entreri> with a webcam
[04:20] <Tjoppen> -f v4l2 -s 640x480 -i /dev/video0
[04:20] <Tjoppen> or so
[04:21] <Tjoppen> and -t 0.01 to limt the number of frames
[04:21] <entreri> ok thanks, I forgot the -s
[04:21] <Tjoppen> so a single picture should be something like ffmpeg -t 0.01 -f v4l2 -s 640x480 -i /dev/video0 -qscale 2 out.jpeg
[04:22] <entreri> and by curiosity, can I take a picture of the terminal (TTY) and/or of xorg ?
[04:23] <Tjoppen> -f x11grab -s `xwininfo -root|grep geometry|awk '{print $2}'` -r 30 -i :0.0
[04:23] <Tjoppen> is what I use for desktop capture
[04:23] <Tjoppen> -f alsa -i default   for mic
[04:24] <Tjoppen> I have a script that does all of those. sadly my webcam seems to be broken
[04:24] <entreri> wow, I rarely deal with complicated commands like this, that's sick:P
[04:24] <entreri> thanks a lot
[04:25] <Tjoppen> yeah, it's because the x11grab input doesn't default to the current resolution for some reason
[04:25] <Tjoppen> but it works wonderfully, even with multiple screens
[04:29] <Tjoppen> ah, one downside: my screens have different resolutions. it doesn't fill in the gaps with black
[04:38] <burek> entreri, you can also use -vframes 1
[04:38] <burek> instead of -t
[04:46] <entreri> I tried both, but I get errors ; [video4linux2,v4l2 @ 0x9660b60] Cannot find a proper format for codec_id 0, pix_fmt -1
[04:46] <entreri> /dev/video0: input/output error
[04:47] <entreri> can't find anything on the web
[04:50] <entreri> that's what I did ; sudo -u user ffmpeg -f video4linux2 -s 640x480 -i /dev/video0 -t 0.01 test.jpeg
[04:50] <entreri> it does the same as root
[05:03] <burek> if you just installed your ffmpeg
[05:03] <burek> through apt-get or similar
[05:03] <burek> its possible that you don't have a proper codec built in ffmpeg
[05:03] <burek> can you please use pastebin.com, to show your command line and its output?
[05:07] <entreri> burek: that's right, I just installed it through pacman
[05:08] <entreri> should I look for a codec or something ?
[05:08] <burek> i dunno
[05:08] <burek> i dont see the output
[05:12] <entreri> pastebin.com/nLh52ehU
[05:13] <burek> the command is missing
[05:15] <entreri> the command that generated that is ; ffmpeg -f video4linux2 -s 640x680 -i /dev/video0 out.mpeg
[05:15] <entreri> yeah sorry I forgot
[05:15] <entreri> you want a new pastebin with the command instead ?
[05:16] <burek> try something more common like: ffmpeg -f video4linux2 -s 640x480 -i /dev/video0 -vcodec libx264 -crf 20 out.mp4
[05:18] <entreri> same...
[05:18] <entreri> the webcam works with flash also
[05:20] <entreri> maybe it needs to be done inside an X server ?
[05:20] <entreri> I do the command in TTY1
[05:20] <entreri> ctrl-alt F1
[05:21] <burek> what exactly is your goal
[05:22] <entreri> well, taking pictures and video using ffmpeg:P
[05:22] <entreri> but it doesn't work and I don't know why
[05:23] <burek> it seems your camera sends a video stream which ffmpeg doesn't understand
[05:23] <burek> your best bet is to try to compile ffmpeg
[05:23] <burek> or grab a static build
[05:23] <burek> and see if that works
[05:23] <burek> it will be faster
[05:24] <burek> https://sites.google.com/site/linuxencoding/builds
[05:24] <burek> just download ffmpeg, unpack and run
[05:25] <burek> but run it with ./ffmpeg ...
[05:26] <entreri> damn
[05:26] <entreri> I just found something
[05:26] <entreri> my driver is linux-uvc
[05:27] <entreri> and it doesn't support v4l2
[05:27] <entreri> you were right about the stream that ffmpeg did not understand:P
[05:28] <entreri> well, I can at least record sound
[17:45] <francogrex> Hi I am using this command to make a conversion: ffmpeg -i movie.avi -target pal-dvd -aspect 16:9 -sameq movie.mpg
[17:45] <francogrex> But I'd like to reduce the size of the mpg a little bit, which parameters can help me do that without compromosing image and sound quality a lot?
[17:46] <Mavrik> first of all
[17:47] <Mavrik> -sameq doesn't do what you think it does, lose it :)
[17:47] <francogrex> so it's useless here?
[17:47] <Mavrik> yeah, it basically just ruins your qualiy
[17:48] <Mavrik> otherwise, use bitrate parameter to "set" quality
[17:48] <francogrex> jeez, good to know
[17:48] <Mavrik> -b 2000k
[17:48] <Mavrik> or somesuch
[17:48] <Mavrik> depending on how big you want your file to be
[17:48] <JEEB> sameq is the most misused parameter in ffmpeg I think
[17:48] <francogrex> what is the default bitrate?
[17:48] <JEEB> 200k or so?
[17:48] <JEEB> some quite low figure
[17:49] <Mavrik> francogrex, very low, bout 200 or 300k
[17:49] <Mavrik> JEEB, yeah, it has a terrible terrible name :\
[17:49] <francogrex> so maybe I should set it to 100k ?
[17:49] <JEEB> ...
[17:49] <JEEB> > DVD
[17:49] <JEEB> > 100kbps
[17:49] <JEEB> DVDs are generally 8000k or so
[17:50] <sacarasc> Up to 9500 or something.
[17:50] <JEEB> something like that with vbv
[17:50] <sacarasc> 9800?
[17:50] <Mavrik> yeah, standard DVDs are like 4000-900k
[17:50] <Mavrik> *9000k
[17:50] <francogrex> man, I am using the 200k defaukt, no wonder the image is crap
[17:50] <francogrex> but still for this specific one, I need to reduce it
[17:51] <francogrex> it's quite a large movie
[17:51] <JEEB> you most probably don't want MPEG-2 then
[17:51] <JEEB> if you want to compress
[17:51] <francogrex> i'm used to mpg, I use dvdauthor afterwards to make the video_ts
[17:51] <JEEB> MPEG-2 is pretty much needed for DVDs, and you can't really lower the bitrate much with MPEG-2 unless you like blockfests
[17:52] <JEEB> unless your source is a non-moving picture or something
[17:52] <francogrex> blockfests ?
[17:52] <sacarasc> Lots of blockiness.
[17:53] <francogrex> I guessed. I'll give it a shot anyway
[17:54] <francogrex> would changing the aspect 16:9 help instead?
[17:56] <francogrex> WARNING: The bitrate parameter is set too low. It takes bits/s as argument, not kbits/s
[17:56] <francogrex> I typed -b 100k
[17:57] <JEEB> basically I guess it's lower than the encoder would like to :P
[17:58] <sacarasc> That;s only 12.5kilobytes per second.
[17:58] <sacarasc> That's nothing.
[17:59] <francogrex> ok I see the default is about  bitrate=3233.7kbits/s so 100 is indeed too low
[17:59] <francogrex> I would set it ad 2000
[18:00] <francogrex> hmm, now the average is 850... although i asked for 2000
[18:02] <francogrex> sorry was a type I forgot the k
[18:02] <francogrex> typing error, now it's aroound 2000, i'll see the final quality
[20:17] <GA-Flix> hi everyone
[20:18] Action: sacarasc flicks GA-Flix.
[20:19] <GA-Flix> am i allowed to add the ffmpeg.exe file to a project which executes the file hidden (no console window visible, but a tooltip shown that says 'Convert to MP3 using ffmpeg.exe in hidden mode. See http://www.ffmpeg.org/ for further information.')
[20:20] <GA-Flix> didn't understand the text on http://www.ffmpeg.org/legal.html ... my english is not the best :(
[20:22] <Mavrik> GA-Flix, yes you are allowed to do that, just make sure your ffmpeg build is redistributable if you want to include it to your project
[20:23] <GA-Flix> i just added the .exe file to the project folder (everyone who wants it can copy it ^^), do you mean that with 'redistributable'?
[20:23] <sacarasc> Can't contain things like faad or faac.
[20:25] <GA-Flix> 'faad' and 'faac' are unknown things for me :( something with encoder and decoder i suppose (wikipedia)
[20:26] <Mavrik> GA-Flix, some libraries that ffmpeg can include have different licenses... when you compile FFMpeg is shows clearly "Licenes: NON-REDISTRIBUTABLE" if that's the case
[20:26] <Mavrik> GA-Flix, which ffmpeg.exe build are you using?
[20:27] <GA-Flix> static x86 (x32)
[20:27] <GA-Flix> http://ffmpeg.zeranoe.com/builds/win32/static/
[20:27] <Freakshow> pasteeater: just fyi:
[20:27] <Freakshow> web2.lab2# ffmpeg
[20:27] <Freakshow> ffmpeg version 0.9.1.git-b4ec645 Copyright (c) 2000-2012 the FFmpeg developers
[20:27] <Freakshow> ffmpeg-devel on freebsd
[20:28] <Mavrik> GA-Flix, Zeranoe's builds are redistributable so go ahead :)
[20:28] <GA-Flix> ok, thank you very much :)
[20:29] <GA-Flix> where can i find such information in the future?
[20:30] <Mavrik> you have to check the licences of the programs/libraries you use
[20:32] <GA-Flix> each file? the "licenses" folder contains 21 licenses ô.0
[20:33] <Mavrik> file?
[20:34] <GA-Flix> "licenses" folder contains 21 files (bzip2.txt, ffmpeg.txt, freetype.txt, ...)
[20:35] <GA-Flix> and each file seems to be a license (i haven't had much to do with licenses yet)
[20:35] <pasteeater> Freakshow: thats newer than i would have guessed
[20:50] <pasteeater> anyone know how to use the select filter to grab an image at specfic percentages of duration? (50%, etc)
[22:41] <Freakshow> pasteeater: at least it matches what I'm using on my customer facing product
[00:00] --- Sun Feb 19 2012


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