[Ffmpeg-devel-irc] ffmpeg.log.20130916

[burek]

[01:51] <Dire> Hello.  I'm a relatively new user to UNIX who's trying to get ffmpeg to run as part of an assignment, but I can't seem to figure out the correct command line string to enter to have ffmpeg pick a folder full of .png images to make a movie from.  I'd appreciate any help anyone might be able to provide.
[01:53] <Dire> I've looked through the -h and online documentation, but it refers to 0-based indices...and I'm not sure exactly how to do that for a folder full of files
[01:59] <vlt> Dire: -i prefix%03d.png for example
[01:59] <Dire> and that should grab all of them?
[01:59] <vlt> Dire: Usually yes.
[02:00] <vlt> All that match the pattern
[02:00] <Dire> Giving it a shot - thank you in advance :)
[02:01] <vlt> Dire: The pattern in my example contains a three digit number.
[02:01] <vlt> Dire: In myexperience it is important that the numbers are sequential.
[02:02] <Dire> all the files are animateslabmodels.0000.png through animateslabmodels.0299.png
[02:02] <Dire> So I put in ffmpeg -i animateslabmodels.0%03d.png g582.mov
[02:03] <Dire> It made a .mov file, so let me take a look and see if it worked
[02:05] <Dire> Awesome, that worked perfectly!
[02:06] <Dire> I didn't know the %03d trick before - adding that to my shortlist of things to remember for this class!
[02:06] <Dire> Thank you so much vlt!
[02:16] <klaxa> oh ffmpeg is in assignments? nice
[02:16] <klaxa> also, if they have 4 digits, %04d is "cleaner"
[02:18] <Dire> "computational methods in geoscience" - ffmpeg is our first assignment in learning how to find, download, unpack, configure, install, debug, and run an open source program
[02:19] <Dire> Thanks for that - I'll remember that too!
[02:19] <klaxa> it's the posix string format for a 4-digit integer with 0 padding
[02:20] <klaxa> i.e.: 0000 up to 9999
[02:20] <Dire> Gotcha
[02:22] <Dire> Thanks so much for the help.
[05:48] <vl4kn0> Hi, I'm writing a program for silent/black frame detection. I know how to determine that a frame is black and I know how to determine that samples are silent, but how do I determine that frame is both black and silent at the same time?
[08:23] <tramm> Any idea if I could find static ffmpeg build for 2.6.18-348.4.1.el5 anywhere? For example http://johnvansickle.com/ffmpeg/ starts from 2.6.32.
[08:27] <tramm> I've found 20120806 version of johnvansicle's build, but this is probably for 2.6.32 too. Do I have a chance running any decent ffmpeg on 2.6.18 at all?
[09:08] <arvind> Hi can some help me understand how to interpret FFMPEG version. For instance I see the following strings in version.h in two different copies of FFMPEG that I have "git-2013-09-03-493ebbd" & "N-37287-g9276467"
[09:08] <arvind> Specifically, what is the significance of the "N-37287" prefix in the second version string?
[09:10] <sim590> how does one finds the audio format of a file named without an extension with ffmpeg?
[09:11] <relaxed> ffmpeg -i file
[09:11] <GoaLitiuM> -i file
[09:12] <sim590> When i play it it says: MPEG-2 / MPEG-4 but when I rename it .mp4 and try to play it through a music player that needs the right extension, it doesn't work
[09:12] <sim590> or m4a
[09:13] <sim590> oh sry.. I thought myself in mplayer chat.
[09:13] <sim590> I got this "Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Our\ Lady\ Peace\ -\ Innocent.m4a'"
[09:14] <sim590> oh sry. I think it's mp4a.
[09:14] <sim590> thanks guys
[09:37] <hendry> is there a way to make ffmpeg autorotate videos based upon ffpeg rotate metadata?
[09:39] <hendry> ffprobe rotate metadata... i should have said
[09:42] <relaxed> tramm: No, my older builds supported 2.6.26. You'll have to build ffmpeg yourself.
[09:44] <relaxed> hendry: if there's metadata you can test for you can script it.
[09:50] <arvind> How do I interpret FFMPEG version. For instance I see the following strings in version.h in two different copies of FFMPEG that I have "git-2013-09-03-493ebbd" & "N-37287-g9276467". Specifically, what is the significance of the "N-37287" prefix in the second version string?
[09:52] <GoaLitiuM> first one is the git commit hash
[09:52] <arvind> Sure. What might "N-37287" mean
[09:53] <GoaLitiuM> probably combination of build number and another hash perhaps?
[09:53] <GoaLitiuM> no idea, it's really not documented anywhere, or i can't just find it
[09:54] <arvind> Sure.  Thanks for the help. I couldn't find that information anywhere either.
[10:07] <saste> GoaLitiuM, the X in N-X is an increasing version number
[10:08] <GoaLitiuM> so it's a build number then
[10:08] <GoaLitiuM> what's the latter part then?
[10:09] <saste> the git version hash
[10:10] <GoaLitiuM> i thought the first one is the commit date and hash
[10:11] <saste> i have this in my computer: N-56282-gb3dbe91
[10:18] <arvind> saste, so does X increase by 1 everytime?
[10:19] <arvind> and secondly why are there two different formats for the version string?
[10:20] <BurnerGR> How can i interrupt a transcoding cleanly?
[10:20] <BurnerGR>  ctrl-c stop the transcoding, but it sems to fail to write the moov atom before exiting, leaving a broken file.
[10:22] <GoaLitiuM> press q
[10:22] <Mavrik> BurnerGR, press q.
[10:23] <BurnerGR> aaah ok, thanx :)
[10:27] <saste> arvind, yes X increase by 1, different formats are used for nightly builds and for releases
[10:44] <tramm> relaxed: I have another server running 2.6.32 in the same institution, probably I'll try to use that over ssh. Is there a meaningful way to do it without too much crazy hacking?
[10:46] <tramm> Has anybody experience in using ffmpeg in another server over ssh to convert files in main server? Any suggestions?
[10:50] <Mavrik> uh
[10:50] <Mavrik> do you have IO to handle that?
[10:54] <tramm> Mavrik: IO meaning bandwith etc?
[10:54] <tramm> An easy solution would be to write a script to upload, convert and dowload. Do I have any better ways to do it?
[10:55] <Mavrik> with that you'll lose more time uploading stuff up and down than you'll get by encoding on another machine
[10:55] <Mavrik> buy more sockets.
[10:55] <Mavrik> if you must do that, mount your SAN on target machine
[10:55] <Mavrik> so you won't waste time before and after encode with shuffling bits around
[10:56] <tramm> Actually, I have my user account shared on both servers, I can just start conversion on another server and the file will still be where I need it to be.
[12:53] <hendry> what is the "right way" to rotate a video? given metadata of rotate 180....  using the transpose option?
[12:54] <Mattias> transpose, yes
[12:59] <hendry> so 180 = -vf "transpose=0" ? mapping seems a bit non-straightforward
[13:40] <vinkla> hey guys, I'm having a problem with exporting two seperat png sequences into one http://pastebin.com/raw.php?i=ZPfwJnaX
[13:40] <vinkla> Error: [NULL @ 0x7fc84981ee00] Unable to find a suitable output format for '[top]'
[16:56] <Theo_> Hi! I'm using avio_open + avformat_write_header to write a audio-stream into a file on disk. I need to make the header AES encrypted. Is there any built in support for this in ffmpeg? Or how may I go about encrypting the data and then decrypting it on read?
[17:03] <Ankhwatcher> Hey! I want to extract screenshots from an mp4 file at scene changes, how can I do that?
[17:04] <Ankhwatcher> I'm trying this command:
[17:04] <Ankhwatcher> ffmpeg -i knorr_cib.mp4 -vf select='gt(scene\,0.4)',scale=855:480 -vsync 0 -an keyframes%03d.jpg
[17:04] <Ankhwatcher> but it gives lots of errors
[17:32] <pyBlob> I'm trying to sharpen a video before display with ffplay ... but it doesn't work: http://pastebin.com/fnuhqjdR
[17:33] <durandal_1707> it works here
[17:34] <pyBlob> then I'm probably doing something wrong
[17:34] <durandal_1707> well paste full and uncut console output next time
[17:35] <pyBlob> actually that is the full uncut console output
[17:35] <pyBlob> (apart from the url)
[17:35] <durandal_1707> than try with ffmpeg
[17:36] <durandal_1707> or use -vf instead of -filter:v
[17:37] <pyBlob> using -vf instead works, thanks =)
[17:48] <Theo_> Is libavformat reading and writing possible to combine with AES 128 bit encryption?
[23:53] <Guest4966> Hey there, I am trying to debug an error with the ffmpeg api. ffmpeg seems to be able to read data from a file but the avcode_decode_video2 retuns a fail code. I was wondering if there were ways for me to debug this/collect more information to ask for help. The code is a project I am porting to windows. It works perfectly on linux but not on windows. I am using cygwin with gcc 4.8. I am also using the percompiled binaries for ffmpe
[23:54] <Guest4966> any help is much appreciated.
[23:55] <durandal_1707> Guest4966: what error?
[23:55] <durandal_1707> if you want help provide more information
[00:00] --- Tue Sep 17 2013