[Ffmpeg-devel-irc] ffmpeg.log.20121104

[burek]

[01:10] <Yulth> Hi everyone!
[01:12] <Yulth> Is there any trick to convert from mp3 to aac-he loosing minimum quality? Any specific option? I ask this because when I convert from flac to HE-AACv2, the result is BRILLIANT even at 40kbps, but when I convert a MP3 file (192kbps) to 40k HE-AACv2 it sounds very bad...
[01:12] <Yulth> any idea?
[01:18] <durandal_1707> Yulth: because transcoding is stupid
[01:29] <Yulth> durandal_1707: when one is looking for save bandwidth, it becomes important :)
[01:53] <Sashmo> is there any way to check the field order of a file??
[02:15] <kode54> huh
[02:15] <kode54> I have a MPEG TS video that shows a start time for the video stream
[02:15] <kode54> I need to add that time to the audio track on conversion
[02:16] <kode54> stupid ffmpegsource for avisynth doesn't take that time into account, so the audio is ahead of the video by that time
[02:16] <kode54> maybe I should just use avisynth to offset the audio
[03:07] <grepper> kode54: maybe asyncts would be of use (ffmpeg).  Haven't used it myself.
[05:33] <fling> Hello!
[15:57] <raijin> why is there a lack of avifile replacement?
[15:57] Action: raijin bows
[16:57] <Sashmo> anyone know of a tool that can transcribe audio to text?  I am looking for a anything that could create subtitles on the fly and overlay them on the video&. I know it wont be great, but I just need some sort of solution as a proof of concept.
[17:29] <An_Ony_Moose> can I truncate a video in time using ffmpeg? Just discard the last x seconds of video, or the last x frames?
[17:44] <sacarasc> Yes.
[17:51] <An_Ony_Moose> sacarasc: how?
[17:51] <sacarasc> -t X, but do to it automatically, you'd need to script it or something.
[17:52] <An_Ony_Moose> what do you mean by doing it automatically?
[17:56] <sacarasc> Rather than work out how much to keep, say how much to discard.
[18:12] <An_Ony_Moose> sacarasc: oh right. Thanks
[18:16] <cek2> Hi. How do I embed subtitle from file into AVI?
[20:53] <darkstarbyte_> Anyone else seeing mpeg2video has a weird multithreading bottleneck
[20:53] <darkstarbyte_> I can only get it to use 50% cpu power of my four cores
[20:53] <darkstarbyte_> I did this on ram disk
[20:53] <darkstarbyte_> and my cpu at its full clock speed.
[20:55] <SquirrelCZECH> hi !
[20:56] <SquirrelCZECH> I have usb webcam... and I wanted to stream it with ffserver but I've got problem...
[20:56] <SquirrelCZECH> ffmpeg stream over network gots 2s delay...
[20:56] <SquirrelCZECH> and even when I try to use ffplay on the computer with webcam I've got 2s delay
[20:57] <SquirrelCZECH> ffplay -f video4linux2 -i /dev/video0 ....
[20:57] <Mavrik> SquirrelCZECH: that's normal
[20:58] <SquirrelCZECH> but is there a way to get rid of it?
[20:59] <Mavrik> not really
[20:59] <Mavrik> especially if you don't understand what you're doing
[20:59] <Mavrik> you can't have completely no latency live streaming
[21:00] <SquirrelCZECH> I didn't say I can't have completely no latency
[21:00] <SquirrelCZECH> but 2s is just too much
[21:01] <SquirrelCZECH> and I am not talking about the streaming part
[21:01] <Mavrik> then you're going to have to investigate where the latency comes from
[21:01] <SquirrelCZECH> I've got 2s delay even with pure "ffplay -f video4linux2 -i /dev/video0"
[21:01] <Mavrik> and fix accordingly
[21:01] <SquirrelCZECH> ...
[21:01] <SquirrelCZECH> my only clue is ffmpeg
[21:01] <Mavrik> (capture device, capture buffer, encoder, streamer buffer, player buffer)
[21:01] <SquirrelCZECH> :-/
[21:01] <SquirrelCZECH> maybe point is that I don't know how and I am asking for advice?
[21:02] <An_Ony_Moose> SquirrelCZECH: try with a lower resolution and see if that helps
[21:02] <Mavrik> SquirrelCZECH: if you get delay when using ffplay on your input device
[21:02] <Mavrik> then you're getting latency from your capture device and V4L2 system
[21:02] <Mavrik> so investigate this
[21:02] <Mavrik> as An_Ony_Moose said - lower resolution, framerate
[21:02] <Mavrik> check if your camera has a buffer
[21:02] <Mavrik> check if you can change V4L2 buffer
[21:03] <SquirrelCZECH> "Read bufffers : 0" means no buffer?
[21:03] <SquirrelCZECH> this is what v4l2-ctl tells me... but I will tri to find anything, thanks
[21:06] <SquirrelCZECH> wait... if other programs (mplayer and skype) are able to open the webcam without delay... is it really problem with v4l2?
[21:07] <Mavrik> SquirrelCZECH: yes
[21:07] <SquirrelCZECH> ok
[21:07] <Mavrik> because you really don't have anything between your webcam and screen if you're using ffplay
[21:07] <darkstarbyte_> No one else gets my bottleneck that I listed above?
[21:07] <Mavrik> SquirrelCZECH: also check ffmpeg input buffer settings
[21:08] <Mavrik> darkstarbyte_: honestly not many people still bother with MPEG-2 :)
[21:08] <Mavrik> but I have seen it perform less than idealy on multicore machines
[21:08] <darkstarbyte_> 600fps is great, but I should be getting 1200fps
[21:09] <darkstarbyte_> I am not sure how to find where it is bottlenecking, because maybe I could fix it.
[21:09] <Mavrik> SquirrelCZECH: try also "-analyzeduration 0" (or some low value) and check the rtbufsize parameter in documentation
[21:10] <Mavrik> darkstarbyte_: running on just few of the cores means it's usually a synchronization issue
[21:10] <Mavrik> so you have to look for mutexes being taken
[21:10] <Mavrik> (try strace)
[21:10] <darkstarbyte_> ok
[21:10] <darkstarbyte_> I will get the test video and start it up again.
[21:10] <Mavrik> SquirrelCZECH: also "-fflags nobuffer"
[21:11] <SquirrelCZECH> ok, thanks
[21:13] <darkstarbyte_> Mavrik, Is video scaling multithreaded also?
[21:13] <darkstarbyte_> Not using it
[21:13] <darkstarbyte_> Just something I thought it was before.
[21:13] <Mavrik> scaling a single frame isn't, but ffmpeg will scale several images concurrently
[21:14] <darkstarbyte_> that is awesome
[21:14] <darkstarbyte_> That is something I was thinking to
[21:14] <darkstarbyte_> If it was not threaded for more than one frame that would be a simpler fix.
[21:17] <darkstarbyte_> the strace log is getting pretty big on the ram disk.
[21:19] <Mavrik> yeah, doing a "-c" would probable be wiser :)
[21:20] <darkstarbyte_> compressed?
[21:20] <darkstarbyte_> Still my ramdisk is fast
[21:20] <darkstarbyte_> A couple hundred MB/s
[21:21] <Mavrik> no, syscall counts.
[21:22] <darkstarbyte_> I have to go right now, I will have the results when I get back and when it finishes.
[22:03] <mike_f> I have some code calling avcodec_decode_video2(...) which normally works fine, but with a new hardware H264 encoder that I'm consuming fails with -1. Is there a recommended way to debug my data or a way to determine what the root cause is, so I can fix my settings to the encoder?
[22:18] <saturation> hi, how the heck I should recode this file for flowplayer I have tried to encapsulate it in the mp4 and flv but mp4 doesn't work in there and flv quality is horrible
[22:18] <saturation> http://pastebin.com/5ib8qKH9
[23:10] <PovAddict> is there a video player that can seek individual frames forwards and backwards?
[23:14] <darkstarbyte_> Mavrik, http://dpaste.com/824600/
[23:14] <darkstarbyte_> futex took a total of 6 seconds through out the 5 minute encode.
[23:14] <darkstarbyte_> I can run it again and add time
[23:18] <PovAddict> this is ridiculous... all I want is the video view and left/right arrow keys to switch frames
[23:18] <darkstarbyte_> reserving and freeing all of that memory took less than 100 micro seconds
[23:19] <darkstarbyte_> PovAddict, This sounds like mythtv
[23:20] <darkstarbyte_> Mavrik, real	4m1.686s
[23:20] <PovAddict> mythtv is an advanced DVR interface for home theatres and stuff
[23:20] <darkstarbyte_> PovAddict, vlc will seek trough certain frames to.
[23:20] <darkstarbyte_> through*
[23:20] <darkstarbyte_> I was talking about mythtv's video editor, unless that is not something your doing.
[23:21] <darkstarbyte_> I will pull up vlc and see the exact keys
[23:21] <PovAddict> vlc has e for next frame
[23:22] <PovAddict> nothing for prev frame
[23:22] <darkstarbyte_> You should be able to set that.
[23:22] <PovAddict> mplayer has . for next, ffplay has s for next
[23:22] <darkstarbyte_> it can be on vlc
[23:23] <darkstarbyte_> under tools ----> preferences
[23:23] <darkstarbyte_> then hot keys
[23:23] <PovAddict> then what? :)
[23:24] <PovAddict> nothing can seek backwards frame-by-frame... I guess a video *editor* would work but I'd rather not use one of those complex featureful NLVEs
[23:24] <darkstarbyte_> hold on, I have to find it again
[23:25] <darkstarbyte_> try the letter p
[23:26] <PovAddict> that goes to the previous element of the playlist, or to the beginning of the video if there's nothing else in the playlist; it's equivalent to the |<< toolbar button
[23:26] <darkstarbyte_> that doesn't work
[23:26] <darkstarbyte_> umm
[23:26] <darkstarbyte_> hmm
[23:26] <darkstarbyte_> I will ask directly from the advanced users.
[23:27] <Guest84024> Can anyone tell me why ffmpeg is faster in windows then it is in ubuntu??
[23:27] <darkstarbyte_> Guest31538, Your most likely using an old version
[23:27] <darkstarbyte_> on ubuntu
[23:27] <darkstarbyte_> They usually get faster every release.
[23:28] <darkstarbyte_> The codecs in ffmpeg that is.
[23:28] <Guest84024> i thought as much but i have problems compiling the latest ffmpeg
[23:28] <darkstarbyte_> git or what?
[23:28] <Guest84024> yeah git
[23:28] <darkstarbyte_> I mean the latest stable though.
[23:28] <Guest84024> yeah i've tried a bunch.
[23:29] <darkstarbyte_> What architecture are you using, because I could compile one for you?
[23:29] <Guest84024> amd64
[23:29] <darkstarbyte_> PovAddict, I guess your right, no one that I can find knows.
[23:29] <darkstarbyte_> hold on a bit.
[23:30] <darkstarbyte_> Oh boy I forgot one thing
[23:31] <darkstarbyte_> If I do this then all of your other codecs will have to be upto date also.
[23:31] <darkstarbyte_> like x264
[23:31] <darkstarbyte_> Guest31538, Are you using an old version of ubuntu?
[23:31] <darkstarbyte_> They usually stay current on these things.
[23:32] <Guest84024> Yeah, it was the x246 that wasn't compiling I was following this guide after failing a few times http://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide
[23:32] <Guest84024> and at the bottom it said if you have problems come here so i did lol
[23:32] <darkstarbyte_> Are you using an old version?
[23:32] <darkstarbyte_> like 8.0 or something.
[23:33] <Guest84024> of ffmpeg?
[23:33] <Guest84024> oh  ubuntu
[23:33] <darkstarbyte_> Ubuntu
[23:33] <Guest84024> lol didn't see that line
[23:33] <Guest84024> 12.10
[23:34] <darkstarbyte_> I think they went back to gnome
[23:35] <darkstarbyte_> hmm
[23:35] <darkstarbyte_> in the command line run:
[23:36] <darkstarbyte_> ffmpeg --version
[23:36] <darkstarbyte_> I mean
[23:36] <darkstarbyte_> ffmpeg -version
[23:36] <Guest84024> i currently don't have it installed but i'll grab it from apt-get
[23:36] <darkstarbyte_> On the package manager it should say the version without needing to reinstall it.
[23:37] <Guest84024> ffmpeg version 0.10.5-6:0.10.5-0ubuntu0jon3
[23:37] <PovAddict> looks like I should build one myself
[23:37] <PovAddict> http://www.rob-coenen.nl/lab/html5/frame_accuracy/
[23:37] <darkstarbyte_> Try syncing to the repo
[23:37] <darkstarbyte_> I think it would be something like
[23:37] <darkstarbyte_> apt-get update or something
[23:39] <darkstarbyte_> Guest31538, Even the oldest currently maintained distribution of Linux is using 0.11
[23:40] <darkstarbyte_> I mean
[23:40] <darkstarbyte_> he quit
[23:40] <sean1988> hey i was just here as a guest
[23:40] <darkstarbyte_> hmm?
[23:41] <darkstarbyte_> Were you Guest82024?
[23:41] <dmon> any one have any experience with log-c to rec709 conversion?
[23:41] <sean1988> more then likley
[23:41] <sean1988> you were trying to help me
[23:41] <darkstarbyte_> Run apt-get update
[23:41] <sean1988> I have
[23:41] <darkstarbyte_> darn
[23:41] <dmon> 3d look up tables etc?
[23:41] <dmon> do you?
[23:42] <sean1988> and that's from the ppa as I thought it would be the more up to date version should i unintall ffmpeg remove the ppa and try installing it again?
[23:42] <darkstarbyte_> sean1988, I might be able to find a forum that has a bunch of stuff you can copy and paste to make custom packages, then I can grab a bunch of links.
[23:42] <dmon> for my job we use davinci and scratch assimilate... I'd rather do that myself
[23:43] <sean1988> if it can help i'll try it lol i want to get rid of windows and that's the only thing that's stoping me atm.
[23:44] <darkstarbyte_> If you were like me you would go directly into Gentoo, which was a bad idea.
[23:44] <darkstarbyte_> Yes everything was faster, but you would have to compile everything from scratch.
[23:44] <darkstarbyte_> Much faster than Ubuntu could ever go.
[23:44] <sean1988> i've tried install gentoo on my old machine, but I never got it to boot
[23:44] <darkstarbyte_> Firefox opened in less than one second.
[23:45] <klaxa> wait what
[23:45] <klaxa> it feels like i should install gentoo
[23:45] <darkstarbyte_> Hours of compiling though.
[23:45] <sean1988> I'm planning on making arch when i feel just a little more capable
[23:46] <darkstarbyte_> Don't make everything from scratch on ubuntu
[23:46] <darkstarbyte_> One developer tried, and failed badly.
[23:47] <darkstarbyte_> dpkg-buildpackage -us -uc -nc
[23:47] <darkstarbyte_> That should do it.
[23:47] <darkstarbyte_> Then I just have to grab the links.
[23:47] <sean1988> is that to me?
[23:47] <darkstarbyte_> Maybe I can just make a shell script.
[23:47] <darkstarbyte_> yeah
[23:48] <sean1988> tail: cannot open `debian/changelog' for reading: No such file or directory
[23:48] <sean1988> dpkg-buildpackage: error: tail of debian/changelog gave error exit status
[23:49] <dmon> i know i'm in trouble when i turn to irc for help....you guys aren't' even talking about video and audio encoding!!!
[23:49] <darkstarbyte_> wow
[23:49] <dmon> LOOK UP TABLES???? anyone even heard of them??
[23:50] <dmon> LOG-C to REC709....
[23:50] <darkstarbyte_> have not used either of those.
[23:50] <darkstarbyte_> I can't help you there.
[23:51] <dmon> basically movie cameras shoot in a flat color space, looks like milky rubbish in the files, then a LUT is added
[23:51] <dmon> and it magically looks like what it did on the onset monitor, just better for VFX work
[23:52] <dmon> libav has lutrgb as command but it seems to be limited or maybe I seem to be limited
[23:55] <darkstarbyte_> sean1988, Do you have a multicore computer?
[23:56] <sean1988> yes
[23:56] <darkstarbyte_> How many cores/threads?
[23:56] <sean1988> 8
[23:56] <darkstarbyte_> wow?
[23:56] <darkstarbyte_> I mean
[23:56] <darkstarbyte_> the i7 or bulldozer?
[23:56] <sean1988> bulldozer
[23:57] <darkstarbyte_> nice
[23:57] <darkstarbyte_> http://dpaste.com/824622/
[23:58] <darkstarbyte_> That will use all 8 threads
[23:58] <sean1988> should i save it a bash file or just copy and past it over?
[23:59] <darkstarbyte_> Either way
[23:59] <darkstarbyte_> Though the bash file will be more permanent.
[00:00] --- Mon Nov  5 2012