[Ffmpeg-devel-irc] ffmpeg.log.20121016

burek burek021 at gmail.com
Wed Oct 17 02:05:01 CEST 2012


[01:04] <TheWarden> saste_: thanks so much, that did the job.
[02:28] <pablomurad> Alo
[02:31] <RunawayDevil> Someone here can provide me some support?
[02:43] <RunawayDevil> Someone alive here?
[02:49] <funyun> hi. is there a way to rotate a video without re-encoding it?
[02:57] <RunawayDevil> im here sometime already and no one until now
[02:58] <RunawayDevil> answered me :/
[03:10] <sacarasc> funyun: No, I don't think so.
[03:10] <sacarasc> RunawayDevil: You've not asked a question...
[04:05] <Santiago> Hello.. need some help with my command under windows =)
[04:45] <llogan> funyun: you can rotate it upon playback
[04:55] <Eryn_1983_FL> hey peeps how do i install yuv420p
[04:58] <Eryn_1983_FL>  its not letting me  convert from it to mpeg 4
[04:59] <sacarasc> YUV450p is a pixel format, not a video codec.
[04:59] <sacarasc> *420
[04:59] <Eryn_1983_FL> ?
[04:59] <Eryn_1983_FL> er ok i pb what i got on the cli
[05:01] <Eryn_1983_FL> http://sprunge.us/dJaR
[05:01] <Eryn_1983_FL> tghere ya go
[05:02] <sacarasc> Your ffmpeg is rather old, maybe you could update it? And if you do, something like this should work for Android non-HD: ffmpeg -i input -vcodec libx264 -preset:v slow -b:v 500k -profile baseline -acodec aac -b:a 128k output.mp4
[05:29] <Eryn_1983_FL> :(
[05:29] <Eryn_1983_FL> its on my server where i encode stuff
[07:01] <lake> i would like to try to pass these options to ffmpeg: x264 -q0 -m1
[07:01] <lake> -q0 works, but -m1 doesn't
[07:30] <lake> what container would hold flac/mjpeg
[07:31] <llogan> lake: -qp 0 -subq 1, or use x264opts
[07:31] <llogan> mkv should hold that combination
[07:31] <lake> llogan: thank you so much for the quick replies
[07:31] <llogan> but why mess with those settings anyway? that's what the presets are for
[07:34] <lake> llogan: i could not find any preset that works like -qp 0 -subq 1
[07:35] <llogan> -qp 0 is lossless
[07:35] <lake> llogan: if you know what preset they fall under i would be happy to use it
[07:35] <lake> i am streaming from a v4l device and i -subq 1 seems to be better for streaming live
[07:35] <llogan> anypreset will work with lossles, but only two are really useful: ultrafast and veryslow depending on what you are doing
[07:35] <lake> no xruns
[07:37] <lake> i didn't try ultrafast, actually, that might work.
[07:37] <llogan> you should be using lossless for streaming
[07:37] <llogan> *shouldn't
[07:37] <lake> but i have these home videos that i want to archive.
[07:37] <lake> should i just use -crf 18
[07:38] <llogan> i don't understand what you are doing. first you mention live streaming, and then you mention archiving
[07:40] <lake> llogan: sorry for being unclear. I am "streaming" analog (red/white/yellow cable) to a usb analog to digital converter (red/white/yellow in, usb out) to my pc. 4vl2 is my input device.
[07:40] <lake> the source is a handycam from the 90s.
[07:41] <lake> i see now that streaming implies over the network
[07:41] <lake> that is not what i mean
[07:42] <llogan> ive never used anything like that before.
[07:44] <llogan> if you have unlimited hard drive space you can use lossless if you like.
[07:44] <lake> mmm 120 minutes of film into lossless is going to massive
[07:45] <lake> i have 45 films * 2 hours each
[07:45] <lake> yikes
[07:45] <llogan> of you're limited then -crf 18 should probably be indistinguishable
[07:46] <llogan> what does ffmpeg show for your input streams?
[07:46] <lake> and the only reason i would reconvert the output would be for dvd.
[07:46] <lake> thanks llogan. i think that solves my problems!
[07:47] <llogan> https://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide
[07:47] <llogan> CRF section
[07:48] <lake> 18 looks solid from here
[11:31] <Exatrive> I'm capturing in windows.. the audio is off about -1000ms on capture.. its there a way to compisate for this during the realtime recording to disk?
[11:32] <Exatrive> ffmpeg -f dshow -r 30 -aspect 16:9 -s %resolution% -i video="SCFH DSF":audio="Stereo Mix (Realtek High Defini" -rtbufsize 9835m -pix_fmt yuv444p -vcodec libx264 -preset ultrafast -tune zerolatency -qp 0 -acodec pcm_s16le Z:\%MM-DD-YYYY%.mkv
[11:38] <Exatrive> btw this is being called by a bat file so hence the %.......% stuff
[12:41] <gst-kaps> How to make sure ffplay outputs single channels output audio for single channel input audio ?
[14:18] <burek> does anyone know of any tool that can tell me what is wrong with this flv video (h264+aac): http://teststream765.chickenkiller.com:8091/live.flv
[14:19] <burek> something is wrong with it, but I just can't figure out what
[14:19] <burek> it doesn't play in jw player but it plays somehow in vlc and ffplay...
[14:24] <relaxed> burek: did you try remuxing it?
[14:25] <burek> er.. no, why?
[14:26] <relaxed> try it
[14:26] <burek> well it breaks the whole point kinda..
[14:26] <burek> the webcam is encoding the h264 video
[14:26] <burek> i just add the audio in vlc and mux it into flv and stream it
[14:27] <burek> wait, what do you mean remux it, i am muxing it :)
[14:27] <burek> i thought you said re-encode it :)
[14:28] <burek> webcam gives raw h264 which I'm muxing together with aac in flv (using vlc)
[14:34] <relaxed> Hmmm, maybe flash player can't decode the h264 stream.
[14:35] <burek> let me copy a part from #ffmpeg-devel
[14:35] <burek> described in ffmpeg's vocabulary, vlc is doing this: ffmpeg -f h264 -i /dev/video0 -f alsa -i hw:0 -c:v copy -c:a libaacplus output.flv
[14:36] <burek> when i grab the raw video (not h264) and encode both a/v in flv, then it works
[14:36] <burek> but if i let the webcam encode it and just pass the video + encode the audio, again in flv, then the video doesn't work, but audio does
[14:37] <relaxed> right, flash player doesn't seem to like the h264 stream.
[14:37] <burek> how can I tell what's wrong with it
[14:38] <relaxed> That is a good question.
[14:38] <relaxed> Maybe nothing is wrong with it and the porblem is with flash player.
[14:39] <relaxed> Since ffplay and vlc can play it back that would be my guess.
[14:39] <burek> :/ i updated everything regarding flash..
[14:39] <burek> i would just like to have some kind of a tool
[14:39] <burek> that can compare 2 flv files
[14:39] <burek> so that i can tell what is different
[14:39] <burek> and try to fix it
[14:40] <relaxed> That sounds magical :)
[14:41] <burek> :)
[14:44] <relaxed> Did you try using fmpeg instead of vlc to capture?
[14:44] <relaxed> ffmpeg*
[14:44] <burek> it can't capture -f h264
[14:44] <burek> i don't know why
[14:44] <burek> vlc can
[14:45] <burek> http://pastie.org/private/ajwaid5gea27orjimqmmmg
[14:47] <relaxed> Wouldn't you use -f v4l2 ?
[14:47] <burek> oh yes, my bad
[14:48] <burek> ffmpeg -f v4l2 -vcodec h264 -i /dev/video0 ?
[14:49] <relaxed> you may not have to specify the vcodec
[14:49] <burek> ok, what cmd should i type
[15:22] <relaxed> What is your vlc command?
[15:24] <burek> (to avoid spamming the channel)
[15:30] <burek> if only I was able to grab it only using ffmpeg
[15:31] <burek> I could debug it a low easier
[15:31] <burek> but this way I need to bug people from videolan too
[15:31] <burek> not knowing where the bug actually is
[15:31] <burek> s/low/lot
[15:33] <burek> doesn't work: http://pastie.org/private/7dlsd9wcflbrl5gld3z1rg
[15:33] <burek> works: http://pastie.org/private/fnfbnee7wthe14d8zkexlq
[15:49] <burek> and duration is certainly not 11 minutes.. it is more like a minute or less
[15:49] <burek> also "368 pixels" should be 360.. man.. it is so wrong..
[15:50] <relaxed> burek: does this work? ffmpeg -f v4l2 -s 640x360 -r 25 -i /dev/video0 -map 0:v -c copy output.mkv
[15:51] <burek> input Stream #0:0: Video: rawvideo
[15:51] <burek> output Stream #0:0: Video: rawvideo
[15:51] <burek> :)
[15:51] <relaxed> ffmpeg -f v4l2 -s 640x360 -r 25 -vcodec h264 -i /dev/video0 -map 0:v -c copy output.mkv
[15:51] <burek> [video4linux2,v4l2 @ 0xf79520] Cannot find a proper format for codec_id 28, pix_fmt -1.
[15:52] <burek> just that end it quits
[15:52] <burek> and*
[15:52] <relaxed> ffmpeg -f v4l2 -s 640x360 -r 25 -vcodec h264-pix_fmt yuv420p  -i /dev/video0 -map 0:v -c copy output.mkv
[15:52] <burek> [video4linux2,v4l2 @ 0x1a23620] Cannot find a proper format for codec_id 28, pix_fmt 0.
[15:53] <relaxed> I guess you should file a bug report.
[15:54] <burek> well that is a point :) what should I report? :)
[15:55] <relaxed> ffmpeg -f v4l2 -s 640x360 -r 25 -vcodec h264 -pix_fmt yuvj420p -i /dev/video0 -map 0:v -c copy output.mkv
[15:55] <burek> [video4linux2,v4l2 @ 0x25f4620] Cannot find a proper format for codec_id 28, pix_fmt 12.
[15:58] <relaxed> The reason the stream doesn't work with flash player is because it is yuvj420p and not yuv420p.
[16:01] <burek> fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_H264; //replace
[16:01] <burek> does this have to do anything with that?
[16:02] <burek> #define V4L2_PIX_FMT_H264     v4l2_fourcc('H', '2', '6', '4') /* H264 with start codes */
[16:02] <burek> no, i guess it's not that sorry
[16:30] <Exatrive> well I fixed my sync issues with directshow filters.. hand to flip the  order, Audio=:video= and have -itsoffset 00:00:00.90 right after the video filter..
[16:31] <Exatrive> that is case anyone else comes looking for it.
[16:31] <Exatrive> if I had -itsoffset 00:00:00.90 anywhere else it didn't work but it didn't give any errors ether.
[16:35] <burek> yes, you basically put audio a little bit before the video that way
[16:36] <andyhuzhill> join #libav
[16:36] <ubitux> ?
[16:37] <burek> he probably misspelled it :)
[16:37] <andyhuzhill> :P
[16:37] <ubitux> he's probably provocating
[16:37] <burek> probably just missing /
[16:37] <burek> :)
[16:41] <andyhuzhill> I recently want to write a program to make video monitoring, but I never used ffmpeg, where should I start?
[16:42] <andyhuzhill> I am also interested about the libav, what's the matter?
[16:43] <andyhuzhill>  excuse me?
[16:44] <JEEB> you should just check the headers related to what you'd be doing
[16:44] <JEEB> ffmpeg consists of multiple libraries that it presents
[16:45] <JEEB> libavcodec, libavformat, libavutil, libswscale, libswresample, libavresample
[16:47] <JEEB> libavformat handles parsing of "containers" into streams that can be thrown into decoders or "repackaged", libavcodec handles the decoding and encoding of things, libavutil has various utlilities that other libraries might as well use, libswscale handles conversions between colorspaces, libswresample and libavresample are two libraries that handle audio resampling/mixing
[16:49] <andyhuzhill> Soulhunter, I should go and read some docs about libavformat & libavcodec
[16:49] <andyhuzhill> s/Soulhunter/so/g
[16:50] <JEEB> yeah
[16:50] <JEEB> there are examples available as well
[16:50] <JEEB> otherwise the doxygen and the source code are your friend
[16:51] <andyhuzhill> JEEB, OK, thank you
[17:14] <ubitux> andyhuzhill: help for command line or api usage?
[17:14] <andyhuzhill> ubitux:api
[17:14] <andyhuzhill> ubitux, I want to compiled it into my program
[17:15] <ubitux> andyhuzhill: ok then, https://ffmpeg.org/about.html for an overview of the project, and http://git.videolan.org/?p=ffmpeg.git;a=tree;f=doc/examples;hb=HEAD is a good start for API usage
[17:15] <ubitux> build examples etc
[17:17] <burek> can anyone check what is wrong with this stream.. http://teststream765.chickenkiller.com:8091/live.flv
[17:18] <burek> :S
[17:18] <burek> does anything look odd/wrong or anything
[17:18] <burek> in terms of video frame size, pixel format, encoding, etc
[17:19] <burek> because it won't play in flash players
[17:20] <ubitux> i can't atm, i'm behind a proxy
[17:20] <burek> ok, thanks anyway
[17:20] <ubitux> burek: do you have the issue if you wget it?
[17:21] <burek> you mean, can flash player play it as a file?
[17:21] <ubitux> i don't know what's your issue
[17:21] <burek> flash players play only audio not video
[17:21] <burek> so I don't know how to start debugging
[17:21] <ubitux> you sure the h264 profile is supported by the player?
[17:22] <ubitux> i know some apple devices are limited to a very limited level
[17:22] <ubitux> you might need to check in that direction
[17:23] <ubitux> https://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Levels
[17:23] <burek> hmh, how to set the profile level via v4l2..
[17:23] <burek> is it even possible
[17:24] <ubitux> the device is outputing h264?
[17:24] <burek> yes c920
[17:24] <ubitux> huhu fun
[17:24] <burek> you couldn't even imagine...
[17:25] <ubitux> i'm not sure how you could influence the level
[17:25] <ubitux> maybe just by requesting a different resolution
[17:25] <ubitux> (see the -video_size input v4l2 option)
[17:26] <ubitux> also look at -list_formats
[17:26] <ubitux> to check if there are "different" h264 formats
[17:27] <burek> yes, good idea, didn't try different video sizes
[17:47] <perrth1> Is there any plan to support Freeframe API beside frei0r?
[18:20] <arpu_> hello when i use http auth how should i escape the password if there is a !
[18:20] <arpu_> %21 does not work
[18:33] <relaxed> arpu_: try \!
[19:27] <arpu_> thx relaxed works fine!
[20:35] <sine_> can someone explain to me how video gets changed from 29 fps to 25 fps correctly. do they just skip out hte od frame here and there ?
[20:51] <lake> what is the benefit of 60fps vs 30fps
[20:55] <JEEB> sine_, you can't really do that "correctly" :<
[20:55] <JEEB> some people merge frames, others cut frames off
[20:55] <JEEB> some make fields from frames and encode interlaced
[20:55] <JEEB> etc.
[20:55] <JEEB> lake, unless you have actually a 60fps source, absolutely nothing
[20:57] <sine_> i have 60 fps mode on my camera and you can make smoother slow motion
[20:57] <sine_> you have more source frames to use
[20:58] <JEEB> yeah, sure
[20:58] <JEEB> you can slow down 60fps to, say, 24fps
[20:58] <JEEB> and it'll be still relatively fluid
[20:59] <lake> so if i'm capturing from v4l2, how can i know the source
[20:59] <lake> source fps
[20:59] <JEEB> uhh, the API usually tells you the options >_>
[20:59] <JEEB> some cameras over v4l2 give for example 15fps 1920x1080 but 30fps 640x480
[20:59] <JEEB> etc.
[21:44] <lake> if i convert a .mkv (x264/flac) => ntsc-dvd, i get a ton of buffer underflow messages from ffmpeg
[21:45] <relaxed> join the club
[21:45] <lake> i feel so welcomed
[21:48] <lake> relaxed: is this a known issue
[21:50] <_Adolf_Hit-ler_> lmfao
[22:31] <JEEB> lake, you did do it with multiple passes, right?
[22:31] <JEEB> single pass rate control is completely derp, 2pass can be somewhat better
[23:01] <sine_> Does anyone know a program that i can use to batch process .png or .jpg images. i want to change colour depth and contrast and invert the images for a better black and white camera tracking
[23:07] <llogan> sine_: you can probably use a frei0r filter in ffmpeg to change contrast, and negate filter to invert
[23:09] <llogan> or of course inverstigate imagemagick or graphicsmagick
[23:10] <sine_> ok i have saved what you have said into a text file and will investigate tomorrow after work thanks and good night.
[23:12] <llogan> sine_: the frei0r filter in particular is "contrast0r"
[23:13] <llogan> and graphicsmagick is generally faster, AFAICT.
[23:13] <llogan> (than imagemagick)
[23:14] <lake> JEEB: thanks for the tip. i will try multiple pass
[23:15] <JEEBsv> also underflows just mean that the encoder couldn't keep the stream within the maxrate/bufsize you set
[23:16] <lake> JEEBsv: okay, when i play back the video it's choppy but it sounds great
[23:16] <lake> i'll try multipass now and see how it goes
[23:17] <lake> this has all been one crazy learning experience. i didn't realize how complex ffmpeg is.
[23:17] <lake> very badass tool
[23:59] <Mista_D> what is a value between "sameq" and
[00:00] --- Wed Oct 17 2012


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