[Ffmpeg-devel-irc] ffmpeg.log.20141125

burek burek021 at gmail.com
Wed Nov 26 02:05:01 CET 2014


[00:00] <TSM> the odd thing is how it plays on the BB10, it starts, knows the length of the video 27s then stops after 7 seconds, if i take qtfaststart off then BB10 complains of a codec error
[00:01] <TSM> another odd thing, if i do not send a Content-Length header to the device over html then the video plays correctly
[00:01] <TSM> all this time it works fine on desktop chrome/firefox
[00:02] <TSM> I have done webinspection on the BB10 and it always downloads the whole file before playing it so very odd
[00:04] <llogan> TSM: are you playing it "directly" on the device (uploaded to device and play with native player) or via a browser, or some other way?
[00:06] <TSM> via browser, if i save it then play it all is fine
[00:07] <TSM> the browser on the BB10 offloads the playing to the video app
[00:07] <TSM> it is odd
[00:13] <llogan> TSM: i don't know what to suggest here other than trying a simpler command using defaults and seeing if any of your options cause the issue
[00:13] <llogan> omit audio, etc
[00:15] <llogan> unrelated to the issue, but you have support for libfdk_aac, so why are you using the native AAC encoder?
[00:20] <TSM> dont know about the aac, i read about libfdk so based on your question it seems like it should be the better encoder
[00:21] <TSM> i wish the x264 encoder was faster but i suspect that is because of my lack of CPU extensions that some of the newer procs have
[00:24] <llogan> yes, libfdkaac is better. you could use a faster preset
[00:26] <TSM> superfast is a awfull on the output at 1M, fast seems to be the best tradeoff, im also using baseline to make sure that it will play on andrioid devices
[00:26] <TSM> i still average about 30-35fps encode speed with watermark,drawtext,scale
[08:57] <pagios>  when we say MPEG-DASH server does it mean a plain HTTP Server that servers the MPD file?
[10:04] <sim590> I'm trying to configure urxvt. I've xrdb ~/.Xresources and now urxvt doesn't show with an interactive terminal but only a blank screen.
[10:04] <sim590> oops
[10:05] <The_NetZ> any one care to assist me in assisting another user in setting up libnvenc with ffmpeg?
[10:07] <The_NetZ> https://clbin.com/GFc2C << what we're getting.
[14:01] <Cas_> Hi, I try to stream audio from a decklink card (SDI) to an audio loopback but I keep getting silence. If I stream to a wav it works fine, anyone knows what I could be doing wrong?
[14:02] <Cas_> My commands are: `ffmpeg -f decklink -i 'DeckLink SDI (1)@8' -f alsa hw:0` and `ffmpeg -f alsa -i hw:0 foo.wav`
[14:02] <Cas_> `ffmpeg -f decklink -i 'DeckLink SDI (1)@8' foo.wav` works fine though
[15:44] <ubuntuaddicted> morning/afternoon/evening  having a real difficult time compiling ffmpeg with libnvenc enabled in Arch using a PKGBUILD.  anyone else got ffmpeg to compile with libnvenc enabled?
[15:46] <BtbN> ffmpeg does not have any nvenc support. Ask the guy who made that package what he did there.
[15:48] <ubuntuaddicted> BtbN, oh, so apparently he patched ffmpeg to be able to use nvenc?
[15:49] <ubuntuaddicted> curious why ffmpeg wouldn't want to utilize the onboard encoder chip of kepler and up GPU's
[15:49] <BtbN> Quite surprising though, when i made working nvenc support for ffmpeg months ago, nobody cared. Now it's big news.
[15:50] <ubuntuaddicted> nvidia just released a driver that supports it like a couple fridays ago as far as i'm aware
[15:50] <BtbN> I am using it since months
[15:50] <BtbN> it worked since forever, they just wrote it in their changelog for some reason
[15:51] <ubuntuaddicted> ok, as i said for us normal users who don't compile our own nvidia kernel modules it just came available to us
[15:51] <ubuntuaddicted> oh ok
[15:51] <BtbN> https://github.com/BtbN/FFmpeg/tree/nvenc could use an update to current master though
[15:51] <ubuntuaddicted> in your experience does nvenc provide any better quality than libx264?
[15:52] <BtbN> no
[15:52] <BtbN> just like any other hw encoder
[15:52] <BtbN> x264 is just unbeatable in terms of quality per bitrate
[15:52] <ubuntuaddicted> hmmm
[15:52] <BtbN> But hw encoders use no cpu power and nearly no hardware resources
[15:53] <ubuntuaddicted> the advantage i see is taking all the encoding load off the cpu for those that don't have the best cpu but have a kepler or higher gpu right?
[15:53] <ribasushi> BtbN: doesn't HVEC/x265 outperform x264 by double-digit-percentages in that department?
[15:54] <BtbN> what?
[15:54] <ribasushi> <BtbN> x264 is just unbeatable in terms of quality per bitrate <--- responding to that
[15:54] <BtbN> Nobody was talking h265, let alone h265 hw encoders.
[15:54] <ubuntuaddicted> ribasushi, i don't think rtmp services like twitch support x265 yet though
[15:54] <ubuntuaddicted> does youtube even support it yet?
[15:55] <BtbN> twitch has trouble because users struggle to decode 720p with 60 fps because of too much cpu load. They don't even dare to think about h265.
[15:55] <ubuntuaddicted> lol
[15:55] <ribasushi> they don't, again I was just responding to BtbN's line in isolation
[15:56] <ubuntuaddicted> BtbN, so ffmpeg isn't going to be adding support for libnvenc?
[15:56] <BtbN> I have no idea what libnvenc even is
[15:56] <BtbN> It's not the nvidia nvenc library.
[15:57] <BtbN> That's nvEncodeApi
[15:58] <ubuntuaddicted> well now i'm thoroghly lost. lol  the people who have ffmpeg working with libnvenc enabled say they got ffmpeg to work by using --enable-libnvenc  per here https://github.com/Brainiarc7/ffmpeg_libnvenc
[15:58] <BtbN> Using that fork propably
[15:58] <BtbN> which isn't even a fork, because only 4 commits
[15:59] <ubuntuaddicted> BtbN, ok, well he got it from this guy's github which actually adds the support for libnvenc https://github.com/agathah/ffmpeg_libnvenc/commit/3b5a7bdccd5ed6b4189f596549fb300e3d3fd6b1
[16:00] <BtbN> Again, i have no idea what libnvenc even is
[16:01] <ubuntuaddicted> BtbN, looking at that commit it's utilizing the nvEncodeAPI
[16:01] <iive> most likely nvidia gpu accelerated encoder
[16:01] <BtbN> Nope
[16:01] <BtbN> That library has a diffrentname
[16:01] <BtbN> -" "
[16:02] <BtbN> libnvidia-encode.so
[16:02] <ubuntuaddicted> libavcodec/nvencoder.c
[16:02] <ubuntuaddicted> libavcodec/nvenc.h
[16:03] <BtbN> That's just the avcodec part.
[16:03] <ubuntuaddicted> BtbN, maybe i should start over. :)   i would like to be able to utilize my GTX 760 hardware encoder to encode video/audio with ffmpeg,  how would I do that?
[16:04] <ubuntuaddicted> doc/examples/libnvenc.c
[16:04] <BtbN> There is no supported way for that currently
[16:05] <ubuntuaddicted> it appears that he used the windows nvenc sdk, reviewed the Sample example and then implmented his own libnvenc encoder type for ffmpeg.  is that a fair statement?
[16:05] <ubuntuaddicted> BtbN, apparently there is a way since it's been done by 2 people using ffmpeg
[16:06] <BtbN> Not using the official version of ffmpeg, but some fork.
[16:06] <ubuntuaddicted> BtbN, right, he started with RELEASE NOTES for FFmpeg 2.4 "Fresnel"
[16:07] <ubuntuaddicted> BtbN, he did it back on Oct 24. https://github.com/agathah/ffmpeg_libnvenc/commits/master
[16:10] <ubuntuaddicted> BtbN, i'm a little confused on naming of these things. I don't fully understand C+ so i'm clearly in way over my head. you call it libnvidia-encode.so where he calls it libnvenc. the name is irrelavant isn't it?  both use a dedicated SIP block for accelerated video processing, and as such, is independent of CUDA cores.
[16:10] <BtbN> He doesn't call it like that, he _links_ against that
[16:11] <BtbN> so it's not the same thing
[16:12] <ubuntuaddicted> ok but again i'm just trying to understand why he was able to get NVENC encoding enabled with his ffmpeg but i'm having troubles
[16:13] <ubuntuaddicted> my config.log is here https://clbin.com/8i0O7
[16:13] <ubuntuaddicted> specifically common.mak:49: recipe for target 'libavutil/opencl.o' failed
[16:31] <ubuntuaddicted> looks like it's getting hung right here libavutil/atomic_gcc.h:31:5: warning: "HAVE_ATOMIC_COMPARE_EXCHANGE" is not defined [-Wundef]
[16:48] <ubuntuaddicted> is there currently plans to enable nvEncodeAPI into ffmpeg?
[17:11] <ubuntuaddicted> BtbN, i see you were the one who worked on the nvenc implmentation in windows.
[17:11] <ubuntuaddicted> BtbN, for OBS
[17:40] <BtbN> yes
[17:47] <Dominique_Michel> Hi, with the following webcam "uvcvideo" 3.17.0 capabilities            : 0x84000001 [VIDEO_CAPTURE,STREAMING,(null)]
[17:48] <Dominique_Michel> v4l2 or guvcview didn't find any standard
[17:49] <Dominique_Michel> According to guvcview, the frame rate of the picture is changing on the fly when the webcam is streaming.
[17:50] <Dominique_Michel> My goal is to record the video from the webcam together with the audio from JACK (jackdbus).
[17:50] <Dominique_Michel> I don't know if it is possible with ffmpeg. The nearest I get is with the command:
[17:51] <Dominique_Michel> ffmpeg  -f jack -ac 2 -i jack -f video4linux2 -s 640x480 -r 8.5 -i /dev/video0 -qscale 3 -r 30 out.mpg
[17:52] <kepstin-laptop> framerate changing on the fly is pretty common with webcams, particularly in the dark; they increase the exposure time pretty dramatically to make the image visible
[17:52] <Dominique_Michel> but I get 2 issues: 1) the aaudio is not in sync with the video, and 2) the frame rate of the video is not 100% correct.
[17:53] <kepstin-laptop> do not use -r as an input option, that's what's breaking the video framerate and sync
[17:53] <kepstin-laptop> you can use the "-framerate" option to request the webcam to give you some framerate
[17:54] <kepstin-laptop> but you'll probably get variable framerate output, that's usually ok.
[17:54] <kepstin-laptop> note that with most webcams, you can get higher framerates by using mjpeg (or h264 if supported) input format; the limit when using raw video is sometimes the usb bandwidth.
[18:03] <Dominique_Michel> With "ffmpeg -f jack -ac 2 -i jack -f video4linux2 -input_format h264 -framerate 3 -i /dev/video0 -qscale 3 -r 30 out.mpg", ffmpeg quit with " Cannot find a proper format for codec 'h264' (id 28), pixel format 'none' (id -1)
[18:03] <Dominique_Michel> Assertion *codec_id != AV_CODEC_ID_NONE failed at /var/tmp/portage/media-video/ffmpeg-2.2.9/work/ffmpeg-2.2.9/libavdevice/v4l2.c:805"
[18:06] <kepstin-laptop> well, then your webcam probably doesn't support it (you can check with the -list_formats all input option)
[18:09] <kepstin-laptop> (as an additional note, the webcam will usually round up the "-framerate" option to its nearest supported framerate; e.g. the one in my laptop only supports 15 and 30fps)
[18:12] <Dominique_Michel> Thanks, mine use a very low framerate, around 3 fps, 10 fps as very short peaks
[18:12] <Dominique_Michel> Also, with -list_formats, ffmpeg bail with "/dev/video0: Invalid argument"
[18:13] <Dominique_Michel> It look to be consistent with v4l-info output which find no standard at all
[18:15] <Dominique_Michel> v4l-info find Video_capture "YUV 4:2:2 (YUYV)", 640x480
[19:27] <excalibr> How do you embed idx/sub file into mkv? I know how to do it with .srt but this idx/sub Im not sure which file I should use as the input
[19:32] <ubuntuaddicted> trying to complile ffmpeg with libvnenc enabled using a ffmpeg fork located on github but it's getting hung up on opencl, here's the config.log if anyone can help please. https://clbin.com/flKPy
[19:35] <llogan> ubuntuaddicted: we do not support forks here
[19:36] <ubuntuaddicted> llogan, ah that sucks.  so if I try to compile regular ffmpeg and it fails at the same opencl error then you'll help me?
[19:37] <llogan> if i know an answer, but i probably won't since i know nothing of opencl
[19:40] <ubuntuaddicted> would opencl be required for software like kdenlive (a video editor) or simplescreenrecorder (a video capture program) or obs-studio (a livestreaming software)
[19:41] <ubuntuaddicted> or better yet, what is opencl used for?  i guess i don't even know if I want it enabled. lol
[19:42] <llogan> for ffmpeg specificially, nothing worthwhile
[19:44] <ubuntuaddicted> i see that x264 can use it for lookahead per this http://git.videolan.org/?p=x264.git;a=commit;h=3a5f6c0aeacfcb21e7853ab4879f23ec8ae5e042
[19:46] <llogan> you would have to test to see if your encodings would benefit from it or not
[19:46] <ubuntuaddicted> llogan, right. it's just that i can't compile ffmpeg because it appears like during ffmpeg compilation it can't find some opencl headers.
[19:48] <llogan> IIRC, opencl in ffmpeg is optionally used only by a few filters
[19:49] <ubuntuaddicted> llogan, i see it's used by x264, motionsearch, downscale etc etc.  according to this anyway http://git.videolan.org/?p=x264.git;a=commit;h=3a5f6c0aeacfcb21e7853ab4879f23ec8ae5e042
[19:50] <llogan> yes, that's x264
[19:57] <ubuntuaddicted> ok, so x264 encoder uses opencl, or should I say "can" use opencl for some things like lookahead etc etc
[20:25] <ubuntuaddicted> i'm just hung up on my opencl, i see some header files located in /opt/cuda/include/CL/opencl.h  AND /opt/cuda/include/CL/cl.h
[20:25] <ubuntuaddicted> but also /usr/include/gegl-0.2/opencl/cl.h
[20:37] <brontosaurusrex> interlacing in 2014 > http://paste.debian.net/plain/133499 < do "we" agree?
[20:39] Action: kepstin-laptop agrees
[20:40] <kepstin-laptop> obviously european-centric, americans have to switch all the 25 to 24 or 30, and the 50 to 60 :)
[20:40] <brontosaurusrex> kepstin-laptop: any problems that you see, or would you agree 100% ?
[20:40] <brontosaurusrex> yeah, its a short doc for a specific tv station in eu
[20:40] <kepstin-laptop> main issue is that getting cameras and production equipment that can do 50/60p is more expensive.
[20:41] <brontosaurusrex> well, then shoot 25p, isnt that obvious?
[20:41] <ubuntuaddicted> for some reason ffmpeg isn't seeing my libOpenCL headers.
[20:41] <kepstin-laptop> ubuntuaddicted: do you actually mean ffmpeg? or are you having issues with x264?
[20:41] <ubuntuaddicted> kepstin-laptop, ffmpeg but it's a fork so not sure you want to help me. :(
[20:42] <kepstin-laptop> ubuntuaddicted: you don't want x264 built with opencl anyways, it apparently makes it slower and lower quality.
[20:42] <ubuntuaddicted> kepstin-laptop, im trying to get ffmpeg built with nvEncodeAPI capabilities.
[20:43] <kepstin-laptop> hmm. there are very limited use cases for wanting to use the hardware encode blocks on graphics cards, pretty much limited to "i want to do realtime streaming, and my cpu is already being used for other stuff"
[20:43] <ubuntuaddicted> kepstin-laptop, yeap, that's it
[20:43] <kepstin-laptop> but if that fits your use case have fun, but I don't know anything about it :)
[20:45] <kepstin-laptop> but either way, opencl shouldn't be involved, since opencl means using the graphics card compute resources, so it would e.g. compete with gaming performance.
[20:45] <ubuntuaddicted> kepstin-laptop, trying to utilize this https://github.com/Brainiarc7/ffmpeg_libnvenc but for some reason when I try to configure ffmpeg it's not finding my nvidia.icd
[20:46] <ubuntuaddicted> kepstin-laptop, my last config.log https://clbin.com/9ykup
[20:47] <kepstin-laptop> yeah, you should really try to contact the people working on that repo directly for that. Unless you get lucky and they're hanging around here...
[20:48] <mam_> Hi
[20:49] <ubuntuaddicted> kepstin-laptop, well i have the opencl-headers20 installed on my machine. i also have cuda installed. so i'm not sure why it's failing
[20:49] <mam_> How to merge 2 avi file
[20:50] <kepstin-laptop> mam_: please describe what you mean by merge. do you want a single file that plays the two videos in order? do you want one overlayed over the other but both playing at the same time?
[20:50] <ubuntuaddicted> mam_, this may help http://unix.stackexchange.com/questions/43896/is-it-possible-to-merge-video-files-using-cat
[20:51] <kepstin-laptop> mam_: ffmpeg has an actual faq entry for this: http://www.ffmpeg.org/faq.html#How-can-I-join-video-files_003f
[20:52] <mam_> Thanks I will Chack
[21:15] <mam_> Hi I checked only first video show
[21:23] <mam_> ubuntuaddicted: I checked only first video showed
[21:24] <ubuntuaddicted> mam_, not sure sorry.  personally i use a linear video editor for joining video files but thats overkill for what you want to accomplish and i'm not sure how to accomplish it using ffmpeg and the command line. sorry
[21:56] <MamuDingo> Hi there! Instead of writing a stream to a file, I'd like it to output to stdout. I see in a lot of online documentation that I can use "-" as the output parameter to accomplish this, but whenever I try I get the following error: [NULL @ 0x1be9240] Unable to find a suitable output format for 'pipe:'
[21:58] <MamuDingo> http://pastebin.com/39sTt9E4
[21:58] <kepstin-laptop> MamuDingo: when outputting to a pipe, you have to specify the -f output option, since it can't guess from the filename
[21:59] <MamuDingo> Ah ha... Okay, I'll try that.  Thanks!
[21:59] <kepstin-laptop> note that not all output formats can be sent to a pipe; for example, mp4 doesn't support it.
[22:00] <MamuDingo> Is there any way to tell which formats support piping?
[22:00] <kepstin-laptop> hmm, I don't actually know of any good lists. You can always try and see, it'll give an error if it's not supported.
[22:01] <MamuDingo> Well, trial and error is definitely one way. :)
[22:01] <MamuDingo> Thanks, again!
[22:04] <MamuDingo> rawhide seemed to work for what I needed to do.
[22:04] <MamuDingo> *rawvideo  ... autocorrect. :(
[22:05] <llogan> Cut 'em out, ride 'em in Rawhide!
[22:08] <gokuh> hello i need parameter for ffmpeg: add srt in video but want choose font : dejevu.tiff , but how?
[22:10] <gokuh> "ffmpeg -i video.avi -vf subtitles=subtitle.srt out.avi" this is OK but i want chose font.tiff how...???
[22:20] <Raccoon> best to just wait until someone in the channel can answer your question.
[22:29] <klaxa> gokuh, i think your best bet is to convert the .srt subs to .ass and set a font there (for example with aegisub if you have a GUI)
[22:44] <gokuh> klaxa: THANK YOU i try to do convert ok? thank you
[23:18] <Vimeo> Hello Everyone i need some help with video filter configuration in ffmpeg. I wanne show a picture if on the udp input of ffmpeg is no signal
[23:19] <Vimeo> the output of ffmpeg is published to a rtmp server
[23:51] <ScottMichaud> Got to say, there's one thing that I don't understand about FFMPEG: It sometimes brings my PC to ~100% utilization, but it remains completely responsive. o.O
[23:51] <ScottMichaud> That's some magic. :p
[23:52] <c_14> You can blame your Operating System's load management policies.
[23:52] <ScottMichaud> Or, thank?
[23:52] <c_14> What, you actually want a responsive system?
[23:52] <ScottMichaud> Ideally, yes. :p
[23:54] <ScottMichaud> I often need to babysit processes otherwise my machine stutters like mad. Not so with FFMPEG. Not even aware it's still running if I don't look at PowerShell or my CPU charts.
[23:57] <klaxa> most of the time i can tell from my fans it's running
[23:57] <c_14> You mean the room heater?
[23:58] <klaxa> i only have laptops, they don't heat up rooms very well
[23:58] <c_14> It's all about placement.
[23:58] <ScottMichaud> Pfft. Who wants more than a 35W block heater? :p
[00:00] --- Wed Nov 26 2014


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