[Ffmpeg-devel-irc] ffmpeg.log.20120204

[burek]

[00:10] <madsage> if i were to keyframes value to 4 seconds using flash media encoder.  what is the equivalent with ffmpeg. I see that ffmpeg refers to keyframes as GOP 'groups of pictures' would it be -g 4 ?
[00:10] <madsage> or thats a keyframe every 4 frames?
[00:11] <madsage> at 23fps i would need -g 92 ?
[00:11] <madsage> for a keyframe every 4seconds?
[00:13] <madsage> my wowza is complaining;  Fragment duration greater than suggested range of 1-4 seconds. Adjust keyframe interval accordingly
[00:14] <madsage> i guess i can just try some values. i've seen others using -g 20 in some examples
[00:15] <teratorn> madsage: I *think* that is the GOP size yes
[00:16] <madsage> sweet thanks, i kind of figured that out. but i appreciate the confirmation. i'm fairly new at this stuff.
[00:17] <madsage> i will try a value of -g 20 and see if the warnings go away
[00:17] <burek> -g is the size of group of pictures
[00:18] <burek> (in frames)
[00:18] <madsage> the translation of keyframes to groups of pictures is a little unclear to me still but i can try by trial and error
[00:18] <burek> -g 25 gives you 1 keyframe/sec at 25fps display rate
[00:18] <madsage> keyframes in Flash media encoder are per second.
[00:19] <burek> it means that distance between 2 keyframes is 25 frames
[00:19] <madsage> ahh ok cool, so i was close
[00:19] <madsage> right on, i appreciate the clarification
[00:20] <madsage> i was off quite a bit
[00:20] <burek> :beer:
[00:20] <madsage> heh
[00:20] <burek> :)
[00:20] <madsage> thanks, its 4:20 here
[00:20] <burek> "GOP size is 300 which means one intra frame every 10 seconds for 29.97fps input video"
[00:21] <madsage> =]
[00:21] <burek> http://ffmpeg.org/ffmpeg.html
[00:21] <burek> :)
[00:21] <madsage> aye
[00:21] <madsage> almost beer:30
[00:21] <burek> :)
[00:23] <madsage> wowza seems to want a keyframe every 2-4 seconds. -g 50 should be close most of my media is NTSC standard 23fps or close
[00:23] <madsage> we'll give it a shot. and thanks again
[01:18] <pills> how do i get the "movie" video source when using video filters to obey the vsync option on decode?
[01:38] <praedo> hello
[01:38] <praedo> anyone knows how to duplicate audio channels?
[01:39] <praedo> i have a football match recording where one channel is the environment sound and one channel is an XLR voice speaker input
[02:20] <teratorn> "duplicate" ?
[02:21] <teratorn> praedo: ^
[04:19] <pills> how do i get the "movie" video source when using video filters to obey the vsync option on decode? Trying to combine two video streams using video filters and they are out of sync.
[04:56] <ayaka> does ffmpeg support multi thread?
[07:54] <pills> I have 4 videos I am trying to combine into a single video. This is easy enough to do using the video filter options. My problem is the input videos don't seem to decode properly (first frame is dropped). This seems to be due to how they were encoded wrt timecodes. I can fix this problem for a single video by adding the -vsync 0 option however when combined with the video filters only the first video seems to inherit the vsync option. Is
[07:54] <pills>  there anyway around this (besides reencoding the video)? Thanks.
[09:09] <NapHtaKeRoSene> hi
[09:09] <NapHtaKeRoSene> if i do fabs(doublevar) then is it possible doublevar be < 0 ? i believe i am getting negative float value after clamping
[09:12] <Tjoppen> uhm, of course?
[09:13] <Tjoppen> why else would you use fabs() if doublevar was guaranteed >= 0?
[12:21] <tim> hi, i am using kdenlive to capture a full-hd video with a lossless codec. however i have some issues when using huffyuv ... so i wonder, can anyone recommend a lossless video codec that has a high encoding performance?
[12:34] <fr0ggie> can i make ffmpeg put MOOV atoms at the start of a mpeg4/h.264 file?
[12:34] <gfto> fr0ggie: qt-faststart
[12:35] <gfto> moov atoms can be generated only after the file is ready
[12:35] <fr0ggie> hmm
[12:35] <gfto> run qt-faststart on the encoded mp4
[12:35] <fr0ggie> basically what i have happen is motion (video motion detection/recording) program uses ffmpeg to record videos of events.. Hmm i suppose i could hook on_* to run it
[12:36] <gfto> fr0ggie: unfortunately mp4 is not ment to be used as streaming container (thats what we have mpegts for), so movng the moov is a hack but it works
[12:36] <gfto> the problem is that it can't be put in front during generation
[12:37] <fr0ggie> can you put h.264 into a mpeg-[12] container and expect android devices to support it?
[12:37] <gfto> 3.0 support mpegts
[12:37] <gfto> in addition to http live streaming (the apple prptocol)
[12:38] <gfto> for older devices you can use a player for this
[12:38] <gfto> there is a free one drood player or something that supports hls
[12:38] <fr0ggie> hmm
[12:39] <fr0ggie> See, i have a directory full of recordings from the security cameras which i view from either a nice webpage (on a real browser) or from android browser not so nicely ;)
[12:39] <fr0ggie> I guess qt-faststart as an on_* will work, thanks
[12:40] <fr0ggie> on_movie_end ;)
[12:42] <gfto> i've used this to play hls sreams on android 2.4 devices https://market.android.com/details?id=com.daroonsoft.player
[12:43] <gfto> yeah just run qt_faststart once the file is available and then you can use flash player to view the mp4
[12:43] <gfto> also this file will be playable on iXXX devices (assuming the video is coded correctly)
[12:44] <gfto> using flash you can view them on adroid too
[12:45] <fr0ggie> flash?
[12:45] <fr0ggie> i dont have flash
[12:46] <fr0ggie> I personally dont even use android to view things, but my friend who i set this up for does and he's stuck on like 2.1
[12:46] <fr0ggie> (htc hero on crappy carrier)
[12:49] <gfto> well try daroon then, it may work
[12:53] <fr0ggie> will try later today when i see him, thank you
[12:53] <fr0ggie> ffmpeg is pretty awesome ;)
[16:51] <NapHtaKeRoSene> VIDEO:  [WMV3]  480x360  24bpp  1000.000 fps  832.0 kbps (101.6 kbyte/s)
[16:52] <NapHtaKeRoSene> :)
[16:52] <NapHtaKeRoSene> mplayer output
[16:52] <NapHtaKeRoSene> though it plays ok
[16:54] <phed> hi, is there a way to "test" if a file would be decodable by ffmpeg?
[16:55] <Tjoppen> ffprobe?
[16:59] <phed> hmm i found this example "ffmpeg -v 5 -i episode01.avi -f null -" but i am not sure if this fully decodes or not :)
[17:01] <phed> hmm never used ffprobe, i will try that next :)
[17:01] <Tjoppen> it also depends on what you mean by "decodable"
[17:01] <Tjoppen> you can  just run ffmpeg and check its exit code ($?)
[17:01] <Tjoppen> like, just do the transcode. if $? != 0 then something went wrong
[17:01] <phed> i believe i am doing that there. it's diagnostics
[17:02] <phed> but i worry if that becomes "optimized" since tere's no output :)
[17:03] <phed> but that doesn't seem to be the case
[17:57] <SIFTU> I have a bunch oof small mpeg2 files I want to join. I ran the following command "cat $(eval echo {$first..$last}.mpg) | ffmpeg -i - -target ntsc-dvd -f dvd -q:v 3 dvd$i.mpeg"
[17:57] <SIFTU> and all worked by the audio gets out of sync
[17:58] <SIFTU> any tips?
[18:01] <pills> how do i get the "movie" video source when using video filters on the CLI to obey the vsync option on decode?
[20:54] <avamk> Hello, I've been converting several H.264 .mov videos to WebM via this command: ffmpeg -i [input].mov -sameq [output].webm But for some of the converted videos (why not all?) they would freeze after playing for a few seconds, while the audio would continue. How can I troubleshoot this?
[20:56] <Mavrik> avamk, don't use sameq, it doesn't do what you think it does
[20:57] <Mavrik> avamk, http://www.virag.si/2012/01/webm-web-video-encoding-tutorial-with-ffmpeg-0-9/
[20:57] <avamk> Mavrik: Oh I see, checking out the link now...
[20:58] <Mavrik> avamk, basically there's no easy way of doing it "the same quality"
[20:58] <Mavrik> so you'll have to set approximately the same bitrate manually
[20:58] <Mavrik> for more troubleshooting you should really paste the commandline and output to some pastebin and show it
[20:59] <avamk> Mavrik: OK, I'll try the steps outlined on that page. If it still doesn't work I'll use pastebin. Thanks for your quick response.
[21:03] <avamk> Basic question from new user: my ffmpeg says it doesn't recognise the 'codec:v' option?
[21:06] <drv> some of the options were renamed recently; -vcodec should work instead
[21:06] <drv> (or you can update to a newer ffmpeg release)
[21:07] <pills> I have 4 videos I am trying to combine into a single video. This is easy enough to do using the video filter options. My problem is the input videos don't seem to decode properly (first frame is dropped). This seems to be due to how they were encoded wrt timecodes. I can fix this problem for a single video by adding the -vsync 0 option however when combined with the video filters only the first video seems to inherit the vsync option. Is
[21:07] <pills>  there anyway around this (reencoding is fine)? Thanks.
[21:10] <avamk> drv: Thanks, is there a list of the renamed options? Looks like my ffmpeg also doesn't like others such as '-cpu-used'.
[21:13] <drv> hmm, i'm not sure what -cpu-used does
[21:14] <drv> you might be able to just leave it out
[21:14] <avamk> drv: I am trying to replicate what's here: http://www.virag.si/2012/01/webm-web-video-encoding-tutorial-with-ffmpeg-0-9/
[21:15] <Mavrik> avamk, update your ffmpeg
[21:15] <Mavrik> since it's so old it doesn't support libvpx-specific flags
[21:15] <Mavrik> don't encode WebM with old ffmpegs ;)
[21:15] <avamk> Mavrik: Oh OK. I'll try to update it. But I got it from MacPorts on my Mac, looks like they didn't update it in a while...
[21:16] <Mavrik> hmm
[21:16] <avamk> Might have to compile from scratch...
[21:16] <Mavrik> basically you want 0.9+
[21:16] <avamk> OK
[21:56] <brontosaurusrex> funny problem, if i add -map 0:0 -map 1:0 to command line, then x264 pass loging gets broken, any clues how this two could be connected?
[21:59] <brontosaurusrex> a log http://pastebin.com/J6RgHQF7
[22:31] <jackNDbox> sry for the noob question but what does it mean when I do ./configure and I get a message saying yasm not found?
[22:32] <Monkeypaws> the configure script calls on an app named yasm, which you dont have installed
[22:32] <jackNDbox> k thx i'll go get that
[22:33] <Monkeypaws> YASM is a modular assembler, it is required by the x264 package.
[22:33] <Monkeypaws> http://wiki.razuna.com/display/ecp/FFMpeg+Installation+on+CentOS+and+RedHat
[22:33] <Monkeypaws> ok gl
[22:34] <jackNDbox> oh wow thanks for that link
[23:19] <jackNDbox> anyone have any idea? I am running this command:
[23:19] <jackNDbox> ./configure --enable-gpl --enable-nonfree --enable-postproc --enable-libfaad --enable-avfilter --enable-pthreads \
[23:19] <jackNDbox> --enable-libxvid --enable-libx264 --enable-libmp3lame --enable-libfaac --disable-ffserver --disable-ffplay \
[23:19] <jackNDbox> --enable-libtheora --enable-libvorbis --disable-ffplay --enable-shared --enable-avfilter-lavf --arch=x86_64
[23:20] <jackNDbox> and I get libmp3lame not found
[23:21] <jackNDbox> should I just delete --enable-libmp3lame and move on? or will I have serious problems later?
[23:23] <iive> jackNDbox: do you have the headers needed for using the mp3lame library? usually they are in -dev package.
[23:26] <jackNDbox> honestly i'm not really sure I followed this step by step and didn't have a problem until now
[23:26] <jackNDbox> http://wiki.razuna.com/display/ecp/FFMpeg+installation+on+CentOS+and+RedHat
[23:30] <jackNDbox> I am running cent OS 5.7
[23:45] <iive> jackNDbox: can you find the mp3lame check in the configurel.log file?
[23:45] <iive> it should say what is failing.
[23:52] <jackNDbox> it's saying something like:
[23:53] <jackNDbox> ./configure: line 2845: libswscale/libswscale.pc: no such file or directory...
[23:53] <jackNDbox> ./configure line 2861: libswscale/libswscale-uninstalled.pc no such file or directory
[23:58] <jackNDbox> i dunno i think i'm just gonna take a break
[23:58] <jackNDbox> i've been configuring this server for like 12 or 13 hours now
[23:59] <jackNDbox> i'm probably just brain dead at this point
[00:00] --- Sun Feb  5 2012