[Ffmpeg-devel-irc] ffmpeg.log.20130422

burek burek021 at gmail.com
Tue Apr 23 02:05:01 CEST 2013


[04:57] <green_deep> I found some packet's pos return by ffmpeg is -1,  pkt->pos=-1, why this could happen?
[08:28] <teptanic> Can FFMPEG be used to check a video file for errors? How?
[08:28] <teptanic> --without writing another file, preferably.
[08:53] <hazardous> hi
[08:53] <hazardous> quick question, i am using ffmpeg -ss 00:50:13.01 -t 00:52:27.00 -i a.flv -acodec copy -vcodec flv -async 1 out.flv
[08:53] <hazardous> it splits successfully
[08:53] <hazardous> but the flv when played is near instantly fast forwarded through
[08:53] <hazardous> and shows up with a timestamp like 35175:41 / 2:13
[08:54] <hazardous> is there any way to fix
[10:40] <relaxed> teptanic: ffmpeg -i input -f null - || echo "error"
[10:41] <teptanic> relaxed: thanks. Does that just copy the streams to null, reporting if error in packaging is encountered?
[10:43] <teptanic> I see, it decodes it. (so it says)
[10:43] <relaxed> right, to raw audio/video
[10:45] <relaxed> you could also encode to a specific format and send it to /dev/null, ffmpeg -i input -f matroska ->/dev/null
[10:46] <relaxed> of course -f null should be much faster
[11:04] <MrKim> Hello, I'm going to resample audio with libswresample, and SWR gives error msg to me "Input channel count and layout are unset"
[11:05] <MrKim> How can I set them? example code is helpless..
[11:13] <durandal_1707> MrKim: with av_opt_set_int()
[11:13] <durandal_1707> MrKim: and that is in example, what example you are using?
[12:02] <delicado> hi, what library do ffmpeg uses to decode the shockwave flash files (.swf)?
[12:03] <delicado> i mean, what library does libavcodec uses to decode the swf files, im sure it isn't from macromedia or adobe right? can you guys help me know what it is?
[12:09] <durandal_1707> delicado: libavcodec uses libavcodec for swf
[12:12] <delicado> yeah, but libavcodec is the "whole", i mean the thing is made up of open-source external libraries. so im guessing the swf decoder came from somewhere else and not hardcoded into libavcodec. im wanting to use swf as a GUI frontend for my app, but i want the open-source alternatives.
[12:13] <delicado> i found gameswf, but it is dead as of 2003.
[12:14] <durandal_1707> swf in libavformat&libavcodec supports only video & audio streams
[12:14] <ubitux> swf is format only, so libavformat
[12:15] <ubitux> and indeed the support is partial (no support for all the vector stuff)
[12:17] <delicado> durandal_1707: i tried playing swf games in it (mplayer classic), mplayer displayed the thing correctly, it even responded to keyboard and mouse input, but i know mplayer handled the input handling, still, buttons, text, sprites and stuff was displayed correctly.
[12:17] <delicado> i mean ubitux,
[12:17] <ubitux> mplayer classic? wut?
[12:17] <ubitux> media player classic you mean?
[12:17] <delicado> yeah.
[12:18] <ubitux> it might embed a flash player
[12:18] <ubitux> you can check if the FFmpeg libs support it by just ffplay the file
[12:21] <delicado> maybe, but i tried removing my adobe flash player, and its still working. im guessing its using SWFDEC cause it is what's used in firefox, but i might have to take a look
[12:24] <ubitux> i assume it's on windows
[12:24] <ubitux> on windows, afaict, there is copy of stuff everywhere
[12:25] <ubitux> so it's not unlikely you have a copy of the flash plugin in the mpc directory or even statically linked somewhere
[12:25] <ubitux> swfdec? used in firefox? what are you talking about
[12:25] <ubitux> swfdec isn't maintain for a long time now
[12:25] <ubitux> and firefox supports the official flashplugin
[13:26] <xk0bi> hi i am tring to ffmpeg to fms h264 like ffmpeg -f dshow -i video="Logitech QuickCam Pro 9000" -c:a copy -c:v libx264 -r 20 -b 800k -s 640x480 -preset baseline -f flv  rtmp:... and all i get is black screen can someone help me with that
[13:46] <viric> Hello
[13:46] <MozartsGhost> xk0bi: I am actually just testing now with RTMP from ffmpeg to wowza
[13:47] <viric> I've some broken mpeg2 files... trying to move them to mkv, ffmpeg complains:
[13:47] <viric> Can't write packet with unknown timestamp
[13:47] <MozartsGhost> seems to be working nicely, except my display size is wrong from wowza, versus rtp which is working
[13:48] <MozartsGhost> not sure if rtmp is fully working properly with ffmpeg, I don't know, at least I am getting video and audio, but video is the wrong size, sort of stretches
[13:52] <viric> mh genpts :)
[13:52] <MozartsGhost> o_O heh
[13:57] <Gozzy> good afternoon, i am trying to flattening down a 16 channel prores audio stream to stereo; anyone who has some tips to do this with ffmpeg, sox or somesort of cmd line tool?
[13:57] <xebra> hey, I solved the problem yesterday. With x256 (libx264) it forces some kind of automatic (and variable) frame rate. To really change the frame rate and have a fixed one you need to add "-vsync 1"
[14:08] <xebra> I have another question though. If I am encoding a video at 1fps, should I change the settings for the gop? I see the settings in the presets are like g=250, keyint_min=25, but I guess those are good values for higher frame rates (25fps)
[14:18] <xebra> ok, I'll answer myself: I guess I don't need to mess with those parameters, because ffmpeg will adjust them automatically according to the frame rate. With ffprobe I checked a file I encoded at 1fps, and it says gop=12. So I guess that's ok
[14:21] <MozartsGhost> xebra .. I think it should probably adjust be itself :) hehe
[14:25] <MozartsGhost> I guess if your fps is 1, you could just divide your keyint and keyint_min by 25 ? ..
[14:30] <Bor0> when building ffmpeg on mingw with --enable-openssl, I get: #error "ws2tcpip.h is not compatible with winsock.h. Include winsock2.hinstead.". however, without openssl it compiles fine. what can I do?
[14:31] <MozartsGhost> Question: has anybody experienced any strange display size issues while send RTMP to Wowza or something similar ? .. when I use RTP(udp) to send a stream (720x576) from ffmpeg to wowza with RTMP wowza receives it and says its 720x576, but when u view the stream with JWPlayer it stretches it likes its 4:3 instead of 16:9, however when u use RTP its fine ?, .. I have sent wowza support an email,
[14:31] <MozartsGhost> waiting to hear what they say, so not sure if its wowza or ffmpeg giving the issue. trying to figure it out, anyone have some advice ?
[14:32] <MozartsGhost> I have litteraly tried almost every -aspect -s size settings, and everything that I can .. but still, display issue.
[14:37] <MozartsGhost> I might add, this is a really serious issue for me, I have 32 encoders running 4 channels each, now all of them running ffmpeg (previously vlc) ;) thank you ffmpeg ;) however, RTP is giving network problems, lost frames and such. so want to switch to RTMP which is tcp, more reliable. but now have this display size issue ..
[14:51] <chattychatty> Hello guys, I'm trying to compile ffmpeg in CentOS 6
[14:52] <chattychatty> and when I use the configure command for ffmpeg following this guide: http://ffmpeg.org/trac/ffmpeg/wiki/CentosCompilationGuide
[14:52] <chattychatty> I get this error back:
[14:52] <chattychatty> libfdk_aac is incompatible with the gpl and --enable-nonfree is not specified.
[14:53] <chattychatty> Any ideas? Should I just add the nonfree option? Any conflicts with that or is it just an informality about licensing ?
[14:53] <divVerent> the latter
[14:53] <divVerent> it basically means you cannot give away the ffmpeg package you then made
[14:54] <divVerent> so you can't use this combination for any distributed binary packages, but it's fine for your own system
[14:54] <chattychatty> Thanks, should I just remove the previous --enable-gpl directive?
[14:54] <chattychatty> Or include both?
[14:56] <MozartsGhost> just use both I guess
[14:56] <MozartsGhost> is libfdk much better than libfaac ? .. I've just been using libfaac
[15:20] <divVerent> 14:56:46    MozartsGhost | is libfdk much better than libfaac ? .. I've just been using libfaac
[15:20] <divVerent> y14:56:46    MozartsGhost | is libfdk much better than libfaac ? .. I've just been using libfaac
[15:20] <divVerent> yes, clearly
[15:26] <MozartsGhost> cool, thanks, I will try it out :)
[15:43] <Razorblade> Hi! I've got a probably very simple question but it seem I can't get together with the CLI. I'd like to upscale a Video (mov) from 720p to 1080p, add a watermark (png) and save it to a new file (mp4), but even if I try resizing to 1080p it produces an output of 720p. Could someone help me with the syntax please?
[15:46] <MozartsGhost> -s 1920x1080 -aspect 16x9 ? ..
[15:46] <Razorblade> I was using -vf "scale=h=1080:-1" . I'm using windows btw.
[15:50] <Razorblade> sry http://pastebin.com/QShcPwJy
[16:05] <DonGnom> in which borders could i specify the quality setting for vorbis audio? (-q:a/-aq)
[16:06] <klaxa> if i'm not mistaken, 1-9 float
[16:06] <DonGnom> klaxa: thx i found that in the mean time http://ffmpeg.org/trac/ffmpeg/wiki/TheoraVorbisEncodingGuide it says 0-10
[16:07] <klaxa> ah... heh i'll try to remember that
[16:19] <MozartsGhost> Razorblade: I'm no ffmpeg expert, Yet, but I would try to use "-s 1920x1080 -aspect 16x9" instead of -vf ..
[16:22] <Mavrik> Razorblade, hmm, I just think your scale parameters are off
[16:22] <Mavrik> -vf scale=-1:1080
[16:23] <Razorblade> MozartsGhost: Yeah, that did the trick. But only if I skip the -aspect parameter. Mavrik: Will try that also
[16:23] <Mavrik> also
[16:23] <Mavrik> please don't encode videos without specifying parameters for quality
[16:24] <Mavrik> it'll break your quality :)
[16:26] <Razorblade> Well I haven't used any parameters jet because I watched both videos and it doesn't seem to lack some quality. Maybe a little bit. But the source recording was allready somwhat shaky so it could be. I'll consider that when I'm using a mounted camera next time.
[16:26] <exutux> hi guys, how can I encode a video for to see it on iphone?
[16:26] <MozartsGhost> cool man
[16:26] <exutux> I mean in streaming with opera and iphone
[16:27] <MozartsGhost> exutux: once again, i'm no expert, but I can give u the settings I am using for iphone users ? .. paste me your current command in pastebin .. then I will modify it for you
[16:27] <Razorblade> Mavrik: Your parameter worked as good as Mozarts. Thanks for that.
[16:28] <Razorblade> I'll take a look again about overlaying the watermark and come back if I can't figure it out. Thanks Guys :)
[16:29] <exutux> MozartsGhost: uhm I don't have any command now...
[16:29] <MozartsGhost> Razorblade: I saw something in the documentation about adding images with filters .. but can't remember now, pretty sure its in the ffmpeg documentation tho ..
[16:30] <exutux> MozartsGhost: I will know which kind of codec can I use
[16:30] <exutux> mpeg4? or what and which type of container ... mp4?
[16:30] <Razorblade> Yeah, I've seen it. I believe it was Filters 8:55 but the wrong scale syntax probably messed it up.
[16:30] <MozartsGhost> oh, mpegts container, and x264 codec with aac audio codec
[16:31] <MozartsGhost> exutux: I will give you my x264 codec settings for old apple devices
[16:31] <exutux> thanks
[16:34] <MozartsGhost> http://pastebin.com/vBcrSWD8
[16:35] <MozartsGhost> sorry, lol, change keyint=25 to 250, I made a typo
[16:36] <exutux> MozartsGhost: I will try
[16:36] <exutux> MozartsGhost: the output.mp4 true?
[16:37] <MozartsGhost> output -f mpegts or output.ts, I will be honest I have not tried .mp4 but I guess it would work .. I re-stream via wowza ..
[16:39] <exutux> MozartsGhost: ok I will try and will send you a feedback :D
[16:40] <MozartsGhost> cool man, hope it works ;)
[17:03] <Razorblade> Allright, im back from testing and I figured it out so far. I've got now a syntax which resizes the video from 720 to 1080 using Mavriks Syntax and added a Watermark (http://pastebin.com/FzT5QudU). Unfortunately, the quality suffered (as expected) do you people know good quality settings for youtube uploads?
[17:30] <exutux> MozartsGhost: it does'n works for safari and html5 video :(
[17:46] <Razorblade> Hey mavrik, I think you haven't seen it before. Just want to let you guys know that I was able to figure the right syntax out (http://pastebin.com/FzT5QudU) And yeah, the quality decreased...
[17:46] <Mavrik> Razorblade, yep, use "-crf" to control quality :)
[17:46] <Mavrik> (when using libx264 to encode H.264)
[17:48] <Razorblade> ty :) may you have any suggestions for a decent youtube video?
[17:50] <Mavrik> Razorblade, uhm& "23" is a good baseline
[17:50] <Mavrik> Razorblade, the lower you go, the better quality (and larger filesize)
[17:51] <Razorblade> thanks. 23 is default, isn't it?
[17:51] <Mavrik> Razorblade, um, largely depends on which x264/ffmpeg combo you have
[18:03] <Razorblade> allright, thanks for your help guys. gtg. Bye :)
[19:22] <Gozzy> good evening, is it possible to output to 2 files? something like ffmpeg -i inputfile -ss 00:00:00 -t 00:30:00 first30minoutputfile -ss 00:30:00 -t 01:00:00 second30minoutputfile
[19:30] <Mavrik> Gozzy, it is, but I think time control parameters work on input so you can't do what you want
[19:33] <Gozzy> hmm ok thx Mavrik
[19:36] <Gozzy> when you play a file in ffplay you can see some other kind of timing mechanism (4206 instead of 01:10:x) do you know whats that is? (it does work when you use it in ffmpeg instead of a timestamp)
[19:38] <Mavrik> Gozzy, those are probably seconds :)
[19:41] <Gozzy> lol right
[19:41] <Gozzy> :$ graci
[20:18] <grobda24> I've been recommended this command from multiple places ... "ffmpeg -vcodec copy -acodec copy -i djbarney_hydrogen_qmidiarp_yoshimi_to_ardour_mixing_desk_sync_test.ogv -ss 0 -t 360  djbarney_hydrogen_qmidiarp_yoshimi_to_ardour_mixing_desk_sync_test_CUT.ogv"
[20:19] <grobda24> Ffmpeg reports ""Unkown decode 'copy'"
[20:19] <grobda24> This is on ffmpeg version 1.04
[20:21] <ubitux> move -vcodec copy -acodec copy as output option (aka after the -i ...)
[20:21] <ubitux> also, you can just -c copy
[20:21] <ubitux> ffmpeg 1.0 is old, you should upgrade
[20:29] <Mavrik> yp
[20:29] <grobda24> ubitux: ok, thanks. I'll try that
[22:49] <rainmaker1> Hi, does anyone know if ffmpeg or any other tool can detect streams that have audio/video out of sync?
[22:51] <klaxa> how would you detect that?
[22:53] <rainmaker1> If I know how to detect that I would not ask :)
[23:02] <Diogo> hi what is the command to loop a input file for rtmp streaming?
[23:02] <Diogo> command : /servers/ffmpeg/bin/ffmpeg -re -i "4914731_vIhLy.mp4"  -vcodec libx264 -s 1280x720 -f flv -acodec libfaac "rtmp://server"
[23:02] <Diogo> -loop works?
[23:08] <Diogo> please  this is possible?
[23:54] <lullabud> question about metadata.  i'm trying to have ffmpeg copy all metadata, including Camera tags (as shown by "exiftool -G2 filename"), but can't find a way to do it.  i've tried "-map_metadata 0:s:0" which i read was supposed to copy all metadata, but it's not working.
[23:54] <lullabud> anybody know how to do it?
[23:57] <lullabud> here's some terminal output showing what i'm doing - http://sprunge.us/gTdY
[00:00] --- Tue Apr 23 2013


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