[Ffmpeg-devel-irc] ffmpeg.log.20130217

burek burek021 at gmail.com
Mon Feb 18 02:05:01 CET 2013


[00:06] <Xgates> klaxa: YEAH 1.1 works now :)
[00:06] <klaxa> :)
[00:06] <klaxa> i've messed a bit with mp3 in the last weeks, and it is very easily truncated
[00:06] <Xgates> now to see if the presets in WinFF work with this version
[00:07] <Xgates> you mean just to shorten mp3?
[00:07] <Xgates> or cut...
[00:08] <klaxa> shorten or lengthen, anything goes
[00:08] <Xgates> ok
[00:09] <klaxa> like i said i messed with that a bit in the last weeks, mp3 is arranged in frames, which are a fixed amount of samples (depending on the layer version) you can add and/or take out any frame of an mp3 and it's still spec compliant
[00:10] <Kristian_> I need a freelancer that is working with ffmpeg and ffserver, it's about live audio streaming from usb soundcard. Anyone interested?
[00:15] <Xgates> ok thanks
[00:16] <Xgates> crap I forgot to compile in xvid support errr
[00:16] Action: Xgates has to recompile hehe
[00:16] <defaultro> saste, looks like I found something fishy. When I use the -vf lutrgb with ffplay, it works. However, when I use -vf lutrgb with ffmpeg, it creates a grey video. Most likely, the video I made last night didn't have the lutrgb option
[00:44] <defaultro> saste, will do
[00:45] <defaultro> saste, http://pastie.org/6199394
[00:45] <defaultro> saste, that command generated a blank grey video
[00:46] <defaultro> however, ffplay shows it properly. I can see the channel gets changed
[00:48] <saste> try this one: ffmpeg -f lavfi -i testsrc=d=3 -vf 'lutrgb=r=10+val:g=val-10:b=0+val' out.mp4
[00:48] <saste> also keep in mind that it may be a player problem
[00:48] <saste> it is converting to yuv444p, which is not properly supported by many players
[00:49] <saste> you may want to force the output to yuv420p
[00:49] <defaultro> ok
[00:49] <defaultro> it created out.mp4
[00:50] <defaultro> do you want the output in console?
[00:50] <saste> no try to play it
[00:50] <defaultro> k
[00:50] <defaultro> I played it with mplayer and it's color gray
[00:50] <defaultro> mplayer -fs out.mp4
[00:50] <saste> try with ffplay
[00:50] <defaultro> k
[00:51] <defaultro> i see it
[00:51] <defaultro> very nice :)
[00:51] <saste> then try this: ffmpeg -f lavfi -i testsrc=d=3 -vf 'lutrgb=r=10+val:g=val-10:b=0+val' -pix_fmt yuv420p out.mp4
[00:51] <defaultro> k
[00:52] <defaultro> done
[00:52] <defaultro> mplayer is able to play it
[00:52] <saste> if you have an old mplayer it may not properly support yuv444p H.264
[00:52] <defaultro> got it
[00:52] <saste> that's why it is better to avoid that
[00:52] <defaultro> avoid mplayer?
[00:53] <saste> many players/devices still need to catchup
[00:53] <defaultro> got it
[00:53] <saste> ipad just to name one
[00:53] <defaultro> so from now on, I should use ffplay for playing
[00:53] <saste> no you should avoid H.264 + yuv444p
[00:53] <defaultro> ok
[00:53] <defaultro> i wasn't aware
[00:54] <defaultro> i don't even know what yuv444 is :)
[00:54] <defaultro> so when encoding, should I use the params you used on the last command?
[00:56] <saste> force the pix_fmt to yuv420p, and you got no surprises
[00:56] <defaultro> k
[00:56] <defaultro> i just tried the long command that was failing, it works now :)
[00:58] <defaultro> Thank you so much!!! :)
[00:59] <defaultro> that was one complex troubleshooting
[00:59] <defaultro> :D
[01:01] <defaultro> was it because the recording format was in yuv444 format?
[01:02] <defaultro> recording from my video camera
[01:21] <Diamonte> If I have a video that was recorded upside down. How could I rotate it in one shot with ffmpeg?
[01:22] <Diamonte> from a command line
[01:22] <JEEB> see the video filters listing in ffmpeg.org's documentation
[01:23] <JEEB> there probably is a filter that has a name that rings a bell
[01:23] <juanmabc> -vf "vflip" ?
[01:25] <Diamonte> I just saw that too.
[01:25] <Diamonte> I'll try it out.
[01:56] <Kristian_> Anybody know a freelancer that is working with ffmpeg? Would be grateful for any kind of information. Thank You.
[02:23] <saste> Kristian_, check the consulting page on ffmpeg.org
[02:24] <saste> what do you need a consultant for?
[06:13] <defaultro> wow, the mp4 I uploaded in youtube was 250mb. I downloaded it from youtube, it's downto 33mb. LOL
[06:14] <defaultro> i ran strings then grep crf against it, it didn't have any
[10:09] <alesan> hi! I have an H.264 byte stream file. This is the output of a hardware H.264 encoder.
[10:09] <Kristian_> I need a freelancer that is working with ffmpeg and ffserver, it's about live audio streaming from usb soundcard. Anyone interested?
[10:09] <alesan> Any idea how to treat this with ffmpeg to have programs like Vegas Video read it?
[10:30] <Fjorgynn> alesan: it doesn't work now?
[10:31] <Fjorgynn> alesan: $ ffmpeg -i file.mp4 -c:a copy -c:v copy file.mp4
[10:31] <Fjorgynn> or reencode it with $ ffmpeg -i file.mp4 -c:a copy -c:v libx264 file.mp4
[10:53] <t3ch> hello, why ffmpeg converting so slow command: ffmpeg -i test.mpg -f ogg test.ogg
[10:53] <t3ch> what i need to do to convert little faster
[10:53] <t3ch> :)
[10:55] <sacarasc> Try using more threads, getting a better CPU...
[10:56] <t3ch> aha ok :)
[10:56] <t3ch> how to set more threads ?
[10:56] <sacarasc> -threads X as an output option... Not sure how well theora does multithreading, though...
[10:57] <t3ch> ok
[10:57] <t3ch> will try
[12:09] <pythonsnake> hi
[12:09] <pythonsnake> is there a way to ffmpeg -i x.mp4 -o x.mp4?
[12:15] <ubitux> only remux?
[12:15] <ubitux> oh you mean same filename?
[12:16] <ubitux> doesn't sound safe, especially with mp4
[12:35] <pythonsnake> ubitux: why not
[12:36] <ubitux> because of seeking
[12:36] <pythonsnake> ubitux: the problem i'm trying to fix is
[12:37] <pythonsnake> gstreamer's discoverer can't discover a video
[12:37] <pythonsnake> and im trying to use ffmpeg (remux to the same file) so it fills the missing fields
[12:38] <ubitux> remux to another file, replace the old one
[12:38] <pythonsnake> yeah, that's what i thought of
[12:38] <pythonsnake> thanks
[12:39] <ubitux> it will also reduce race risks on your side
[12:39] <pythonsnake> ubitux: what happens if i dont specify extension but vcodecs and acodecs
[12:39] <pythonsnake> nothing right?
[12:39] <pythonsnake> as in works
[12:40] <ubitux> you need to -f mp4 too
[12:40] <pythonsnake> ffmpeg -i i.mpg -vcodec copy -acodec copy -scodec copy -y o
[12:40] <pythonsnake> o is gonna be mpg?
[12:41] <ubitux> not sure it will work
[12:41] <ubitux> ffmpeg -i in.mpg -c copy -f mpeg out
[12:50] <pythonsnake> thanks ubitux
[13:33] <defaultro> I'm reading this thread. I don't know much about yuv. Why would someone convert yuv422 to yuv420, or viceversa? The videos that we see in youtube, what formats are they? Are they yuv420?
[13:33] <defaultro> http://forum.videohelp.com/threads/316712-Where-can-i-get-YUV444-YUV422-raw-Video-sequences
[13:34] <JEEB> pretty much all video around us is 4:2:0 YCbCr (colloquially called 'yuv')
[13:34] <JEEB> and most decoders of video formats can't even take anything else but that
[13:38] <defaultro> k
[13:39] <defaultro> btw, the 250mb file I uploaded to youtube last night became 33mb, lol. That's a lot of image quality loss with their compression
[13:40] <defaultro> i don't even know how they re-encoded it. I didn't see any 264 string from their mp4 file
[13:41] <JEEB> they've not written that into their SEI for a long time :P
[13:42] <defaultro> was wondering if it was possible to get the picture quality as close as our original
[13:49] <defaultro> am I right that my source which is at 60fps will always be downconverted by youtube maybe to 30 fps?
[13:50] <JEEB> yes, that's how it used to do it at least
[13:52] <defaultro> k
[13:57] <WmA> How can one feed a http ts stream into libx264? Do I need to encode from pipe?
[14:04] <defaultro> JEEB, this is the video I've been playing last night. I'm trying to fix the greencast(bondi blue). I think I got it to a point that it pleases me - http://www.youtube.com/watch?v=ElZAwRgPbvQ
[14:04] <defaultro> glad to hear some comments
[14:45] <hid> Hi I'd like to compare videos on youtube cause I suspect somebody to have the same video as mine (a plagiat). How can I do this with ffmpeg ?
[14:49] <Mavrik> hmm
[14:49] <Mavrik> that's a wierd question
[14:49] <Mavrik> what do you want to compare exactly? content?
[14:50] <hid> yeah metadatas
[14:51] <Mavrik> you see all metadata when doing ffprobe <file>
[14:51] <Mavrik> youtube probably strips all of it
[14:56] <hid> I checked with mediainfo and gstd was the same
[14:57] <hid> evrything was the same
[15:10] <Mavrik> hid: that means nothing since Youtube encodes everything to same quality
[15:10] <Mavrik> hid: you should look at actual video content not metadata
[15:15] <hid> Mavrik : Quality, sound, duration everthing is the same.
[15:16] <hid> How can I do to erase all video/audio metadatas ?
[15:16] <hid> I've never found any such tool.
[15:26] <defaultro> Mavrik, I disagree with what you said that youtube encodes everything to the same quality. I've uploaded videos and pic quality has changed
[15:27] <Mavrik> and where did I say that youtube encodes video to the same quality as you gave them?
[15:27] <Mavrik> their outputs have same parameters and quality.
[15:28] <JEEB> they don't encode for quality, they just have a set bit rate as far as I know
[15:29] <JEEB> thus, they are encoding for a set average bit rate
[15:29] <JEEB> not same quality
[15:29] <Mavrik> *sigh*
[15:30] <JEEB> as far as I know, 'tube doesn't use crf
[15:30] <JEEB> some video thingies use crf with first pass log, and if it becomes too big, they use a second pass with a set bit rate
[17:33] <terr1> I'm playing with ffmpeg (lastest git) and libx264 (lastest git). I'm trying to find some good generel transcoding settings for a html5 website player (progessive download - pseudo streaming). So I was playing with the different x264 presets from ultrafast to veryslow, made a benchmarking shell script to test each setting. I thought this preset setting only effected filesize (compression) not the bitrate? It seems the slower setting the lower bitrat
[17:33] <terr1> e? (I'm using cfr 21 to test)
[17:34] <Fjorgynn> placebo?
[17:52] <xm3> Hi, could anyone help me figure out how to transcode a folder of avis & merge them into one file?
[18:12] <grepper> xm3: have you looked at http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20concatenate%20%28join,%20merge%29%20media%20files  ?
[18:40] <xm3> grepper: thanks looks helpful :)
[18:56] <Emmanuel_Chanel> Helllo!
[18:57] <Emmanuel_Chanel> Do you know how to encode a TS file with dual monaural sounds into a mp4 with two sound tracks?
[19:21] <Fjorgynn> thanks to ffmpeg I can listen to this awesome song
[19:43] <creep> how much power you use your headphones on? i listen to music on my 2x40 ohm headphone at 2x1mW  0.2V/5mA rms and i don't feel like i want more
[20:26] <ioni> hi guys
[20:26] <Mavrik> evenin
[20:26] <ioni> does anyone in here happens to use latest mplayer?
[20:27] <ioni> the configure script is pulling latest ffmpeg
[20:27] <ioni> yesterday mplayer started to crash when using vdpau and i'm not sure where the bug is
[20:27] <ioni> in mplayer or ffmpeg
[20:27] <ioni> http://paste.xinu.at/h9YC/
[20:28] <ioni> Assertion desc->flags & 16 failed at libavcodec/utils.c:511
[20:29] <WmA> blame Charly Sheen!
[20:29] <WmA> ;)
[20:29] <ioni> =)
[20:59] <terr1> Using ffmpeg and x264, how important is customizing keyint, when doing offline transcoding to be played in html5 web player afterwards? does it matter that much? or mostly when doing live streaming ?
[21:01] <Mavrik> mosty when doing live streaming
[21:01] <Mavrik> if you choose low keyint you'll make compression (and by extension - quality) worse
[21:07] <terr1> Ok thanks.. Ill roll with default 250 for now then... If this setting would create problems how would it manifest itself? Mostly when doing manually seeking ?
[21:08] <Mavrik> terr1: by taking a long time to start after seeking
[21:09] <Mavrik> also by long periods of time when blocky errors repair themselves
[21:10] <terr1> Mavrik: Blocky errors.. thoes  artifact squares that sometimes appear when seeking, that takes x amount of time / frames to be corrected?
[21:10] <Mavrik> terr1: those only appear if there's something wrong with transmission
[21:10] <Mavrik> but yeah
[21:10] <Mavrik> usually they don't get repaired until next keyframe
[21:11] <terr1> ah ok thanks for the information :)
[22:08] <defaultro> hey guys, is it possible to add a film look color via ffmpeg?
[22:10] <durandal_1707> defaultro: what film look color means?
[22:11] <defaultro> let me find some videos
[22:13] <Youka> What's the most simple video format to de-/encode with selfwritten code?
[22:13] <defaultro> jump to 1:50 http://www.youtube.com/watch?v=Jis97Eup9_E
[22:15] <defaultro> durandal_1707, this one is nice - http://www.youtube.com/watch?v=JhtHvynfcTQ
[22:15] <Mavrik> Youka: probably motion jpeg or huffyuv
[22:16] <Youka> thx
[22:20] <durandal_1707> defaultro: i still not sure what you mean, there are some hue/equalization filters
[22:23] <defaultro> ok. looks like I will have to experiment to get the desired color
[22:24] <Youka> Isn't there a video format similar simple like wav? Saving raw RGB images with some header data?
[22:24] <Mavrik> not really, since it's very inefficient
[22:24] <Mavrik> huffyuv is probably the closest
[22:24] <Mavrik> or any of other losless codecs
[22:24] <Mavrik> plus, most video isn't recorded in RGB
[22:26] <Youka> Strange :S thx for these informations
[22:34] <defaultro> you guys familiar with twixtor? Can ffmpeg achieve that kind of effect?
[22:35] <durandal_1707> twixtor is some kind of interpolated slow motion?
[22:36] <defaultro> yup
[22:36] <llogan> defaultro: you could look into slowmovideo. it has ffmpeg as a dependency, IIRC.
[22:36] <defaultro> really nice very slow motion
[22:36] <defaultro> k
[22:37] <durandal_1707> there is no such filter in libavfilter, but wrapper or native filter is welcome
[22:37] <llogan> and it costs $0 compared to $595.
[22:37] <durandal_1707> llogan: where is link with price?
[22:38] <llogan> durandal_1707: http://www.revisionfx.com/products/twixtor/pricing/#ae_compatible_4
[22:38] <llogan> defaultro: http://slowmovideo.granjow.net/
[22:39] <defaultro> cool
[22:40] <llogan> i've never tried it because i hate cmake.
[22:47] <llogan> ioni: see commit 259603b
[22:54] <ioni> llogan, yes, i was talking with Carl
[00:00] --- Mon Feb 18 2013


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