[Ffmpeg-devel-irc] ffmpeg.log.20140924

burek burek021 at gmail.com
Thu Sep 25 02:05:01 CEST 2014


[01:08] <UWarbs> I would like to use ffmpeg with my rails project. I noticed the ruby gem, ffmpeg, was last updated in 2009. What is the best way to do a rails wrapper? Specifically I want to get user audio, cut the leading silence, then save the files to a databse. Cutting the leading silence is my only hold up.
[01:57] Last message repeated 1 time(s).
[02:05] <iive> UWarbs: http://digitalcardboard.com/blog/2009/08/25/the-sox-of-silence/ ?
[02:07] <UWarbs> That is essentially what I am looking for, I do not know how to write code in a rails app that can use the command line like that though.
[02:07] <UWarbs> Thank you
[04:44] <MikeJoel> how would you set the screen size of the video? I am trying to convert a swf to mp4 - it just is showing the upper left corner area (really zoomed in)
[04:56] <Nosomy|off> MikeJoel, whats is yours cmdlines?
[04:59] <MikeJoel> I was just trying the basic -i input.swf output.mp4
[05:04] <MikeJoel> sacarasc: that was it. The output works. it creates a mp4 but the upper left area of the swf fills the entire mp4 video so nothing else is seen.
[05:04] <sacarasc> I want what ffmpeg outputs, not the file, but the text on the console.
[05:04] <MikeJoel> as if the swf was being zoomed in to that area
[07:08] <atmosx> hello
[07:09] <atmosx> does this error message means my /dev/video0 doesn't produce any stream? [NULL @ 0x1644bb0] Unable to find a suitable output format for 'pipe:'
[07:17] <Nosomy> yet ffplay still broke to playbacks Matroska Files with HEVC Video Streams
[07:19] <Nosomy> http://pastebin.com/nKzRYSMp
[07:21] <Nosomy> why only ffplay version N-64587-g2571e8f (old version), works fine?
[08:15] <ash__> Hi, I'm new to ffmpeg and wanted to know whether is it feasible to have ffmpeg running in browser(as a plug in maybe) to convert the webcam stream to H264 which can be sent to a streaming server?
[09:31] <myubuntu> libavformat/matroskadec.c:1173: undefined reference to `BZ2_bzDecompressInit'
[09:31] <myubuntu> how to solve this problem?
[09:32] <myubuntu> after I installed some packages, I can't compile my application. I was ok a few days age.
[09:35] <sruz25> so I'm trying to loop, but -loop doesn't seem to work if used after the video, and loop_input/output are no longer present. Any idea how to go about it?
[09:36] <sruz25> oh and loop before the input says Option loop not found
[09:54] <relaxed> exit
[09:55] <relaxed> :)
[10:25] <atmosx> can I run ffmpeg instance on rc.local ?
[10:28] <BtbN> Doesn't sound like the best idea, but i don't see why not.
[10:31] <atmosx> well, it's a pain to login and start ffmpeg (streaming) at every boot.
[10:58] <BtbN> It will hang the boot process, because it's waiting for ffmpeg to finish "starting"
[10:58] <BtbN> it will also run as root
[10:59] <relaxed> cron
[11:08] <Mavrik> mornin
[11:08] <Mavrik> myubuntu, you're not linking your app against bz2 library
[11:25] <jul13t> hello holden, michaelni I'm interested in the Symmetric-key block ciphers project
[11:25] <jul13t> i'm proficient in C and git
[11:27] <jul13t> currently working on a proposal , although i've never done cryptgraphy before
[11:28] <jul13t> i'm deeply interested in cyphers and stuff
[11:31] <sphoorti> Hello folks! I wish to apply for the OPW program for ffmpeg. michaelni are you around ?
[11:35] <sphoorti> The projects symmetric block cyphers and basic servers for network protocols caught my interest.  Networks and information security have been my interest areas and I have experience in git , C and other networking internals  @michaelni
[11:36] <jul13t> sphoorti, looks like he's not around
[11:36] <jul13t> i'm interested in  working on the symmetric key block cyphers
[11:36] <sphoorti> hey jul13t ! yeah looks like it
[11:36] <sphoorti> oh thats nice
[11:37] <jul13t> nice meeting you
[11:37] <jul13t> i dropped by here yesterday and no one was online it seems they're all sleeping
[11:38] <sphoorti> They might be in some other timezone. Maybe they might come online after a while
[11:38] <sphoorti> jul13t:
[11:40] <jul13t> aight sphoorti
[11:46] <relaxed> jul13t sphoorti try #ffmpeg-devel
[11:46] <michaelni> sphoorti, jul13t, another applicant (myra) yestreday already indicated interrest in symmetric block cyphers
[11:47] <jul13t> michaelni, great i'll look at something else
[11:47] <sphoorti> michaelni: basic servers for network protocols is also of my interest
[11:47] <sphoorti> could you tell me something more about it ?
[11:48] <sphoorti> or how I should proceed with it ? michaelni
[11:48] <ubitux> are you guys here for the opw thing?
[11:48] <ubitux> ("guys", right sorry)
[11:48] <ubitux> if so, just join us on #ffmpeg-devel, that's where all the devs are
[11:49] <sphoorti> thanks a lot ubitux :)
[15:26] <sruz25> does -maxrate count in all streams or just the video? Alternatively why does it go over the specified bitrate? Just a link to some more comprehensive 2-pass encoding would be appreciated too.
[15:43] <Ko_deZ> Hi. I am playing around with ffmpeg to see if I can make crude video analyzer. I have managed to get both average QP and standard deviation printout by extending some debug output code in h264.c. My only other wish was to print DTS together with this QP info, but I have been uable to figure out how to get that info. Is it awailable trough the H264Context struct somehow?
[15:48] <MikeJoel> Making a video out of images.  I am not understanding the format for designating the images (0.jpg to 25.jpg) (the docs haven't made it clearer to me)
[15:49] <ubitux> %d.jpg should do
[15:51] <MikeJoel> yes id does - why?
[15:51] <MikeJoel> what if I was doing an image range from 25 to 100
[15:53] <ubitux> %d is a pattern that matches int
[15:53] <ubitux> so any int range would do
[15:53] <ubitux> if you have more files in the directory, iirc there is a -start_number or an option like that
[15:53] <MikeJoel> so if the files were "pic0.jpg" 'pic'%d.jpg
[15:53] <ubitux> and then you also use the option -frames:v 75
[15:53] <ubitux> to stop at 100
[15:54] <ubitux> pic%d.jpg
[15:54] <MikeJoel> ok (thought I had to designate teh string part)... thats a great help... thanks
[15:54] <ubitux> OTOH, if you have pic001, pic002 .. pic321 .. ’ pic%03d (man printf)
[15:57] <MikeJoel> %03 designating 3 digits and 0 showing leading 0s
[16:00] <MikeJoel> ok - now I am understanding - thank you
[16:03] <parkedin> Hey guys. Was following a pretty awesome guide on the website but am encountering an error and was hoping someone may be able to point me in the right direction. Thanks in advance
[16:03] <parkedin> Following this guide: https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu
[16:04] <parkedin> and receiving this error during the final configuration: ERROR: libfdk_aac not found
[16:17] <parkedin> Ran through the libfdk_aac again and removed extraneous spaces from the ffmpeg commands and it appears to be completing.
[16:35] <sine0> does anyone use gentoo here and build ffmpeg
[16:35] <c_14> What's your question?
[16:35] <wintershade> sine0: what a coincidence, a wild Gentoo user connects.
[16:36] <sine0> huh ?
[16:36] <wintershade> sine0: I use Gentoo. and I build ffmpeg.
[16:36] <sine0> im trying to work out what use flags are required as im getting a blocked from building blender, blocking libav
[16:36] <sine0> im assuming that ffmpeg is not being built with the required use flags
[16:37] <wintershade> sine0: which USE flags do you have enabled, and what is your system profile?
[16:37] <sine0> desktop and the default that come with just emerge ffmpeg
[16:38] <wintershade> sine0: do you have any other USE flags enabled or disabled in your make.conf?
[16:38] <sine0> what i dont know is how it can be blockoing libav and to know what flags it want
[16:38] <c_14> According to the blender-2.71-r1 ebuild, it needs: ">=media-video/ffmpeg-2.1.4:0[x264,mp3,encode,theora,jpeg2k?]"
[16:38] <sine0> USE="bindist mmx sse sse2 X glamor udev"
[16:38] <sine0> ok ok ill just put that in
[16:38] <wintershade> sine0: first of all, disable that ugly bindist thing.
[16:39] <sine0> ok
[16:39] <wintershade> sine0: hang on. I'm trying to see what portage is telling me about blender.
[16:39] <wintershade> sine0: can you paste(bin) your exact output after the following line...
[16:39] <wintershade> sine0: emerge -pv blender
[16:39] <wintershade> sine0: ?
[16:39] <wintershade> sine0: tia
[16:40] <sine0> hang on its building!
[16:40] <wintershade> lol
[16:40] <sine0> c_14: way to go with building using the default rtfm instructions
[16:41] <wintershade> when all else fails, read the manual.
[16:41] <sine0> i dont deserve to use gentoo
[16:41] <sine0> hah
[16:41] <wintershade> meh
[16:41] <wintershade> everybody deserves to use Gentoo. IMHO it's the second best thing ever.
[16:41] <sine0> thanks for your time and dont go anywhere the build might fail and ill be running back
[16:42] <wintershade> sine0: anyway... you should have python3_4 in your PYTHON_TARGETS in make.conf
[16:42] <sine0> i do actually love it but its a steep learning curce and when you just want to do somethign quickly because your gf is behind you and you have to start editing make use accpt keyword files just to run a video on a friday night its  pita
[16:43] <sine0> PYTHON_TARGETS="python2_7 python3_3 python3_4"
[16:43] <wintershade> sine0: yes, but like with oter such distros (Arch, Debian, Slackware) you actually learn to configure and use Linux.
[16:43] <sine0> yes im slowly learning through the need
[16:43] <sine0> its good fun
[16:43] <wintershade> sine0: that's cool. you should also have PYTHON_SINGLE_TARGET="python3_4" in your env for blender
[16:44] <sine0> now you have lost me
[16:44] <wintershade> sine0: ok, let's go private cos we're deeply offtopic, don't wanna bother people with it here.
[16:44] <sine0> but i will be back i hear squeals of a femenine nature as i just popped to the toilet
[16:44] <sine0> ok
[17:12] <joeflateau> to stream a video loop infinitely?
[17:12] <joeflateau> ffmpeg -loop 1 -i "...mp4" -f flv "rtmp://..." doesn't work
[17:14] <c_14> loop currently doesn't work for videos
[17:14] <joeflateau> oh
[17:14] <joeflateau> any workaround?
[17:14] <joeflateau> i read about ffplay supporting it, maybe piping output from that into ffmpeg somehow?
[17:17] <joeflateau> guess not
[17:17] <c_14> Maybe `while true; do cat file; done | ffmpeg -i - foobar' ?
[17:17] <c_14> might work
[17:17] <joeflateau> hmm, i'll give it a shot
[17:30] <joeflateau> c_14: while true; do cat "file.mp4"; done | ffmpeg -i pipe: -f ... seems to have worked. thanks!
[17:33] <joeflateau> c_14: welp, actually ffmpeg dies when it tries to actually start over
[17:34] <joeflateau> i guess while true; ffmpeg...; done will have to work for now
[17:39] <c_14> hmm, it was a 50/50 chance I guess.
[17:39] <kepstin-laptop> I'm kind of amazed that ffmpeg can read concatenated mp4 files through a pipe at all.
[17:40] <joeflateau> it can't, turns out
[17:40] <kepstin-laptop> well, in that case, just remux into mpeg ts :)
[17:41] <joeflateau> hmm, remux to mpegts and cat that into ffmpeg?
[17:41] <kepstin-laptop> yeah
[17:41] <joeflateau> i'll give it a shot
[17:43] <joeflateau> that worked!
[17:44] <joeflateau> thank you both, kepstin-laptop and c_14
[17:50] <thebombzen> Sappert yay for cheating
[17:50] <thebombzen> remember how I said I had to do the reading and write a blog post
[17:50] <thebombzen> well I read someone else's blog post that they posted online
[17:50] <thebombzen> oops, wrong channel ^_^
[18:11] <w00ds> howdy!
[18:12] <w00ds> i have an ffmpeg encoding going on right now, is there a way to check how long it will take to finish?
[18:12] <w00ds> is there a way prior to encoding to do a "dry run" and find out the output file size?
[18:13] <c_14> Only if you specify the bitrate/ do 2-pass encoding.
[18:13] <w00ds> is it necessary to specify bitrate?
[18:14] <c_14> No.
[18:15] <w00ds> i did this:  ./ffmpeg -i XXXXXXXX.2014.3D.1080p.BluRay.x264-SPRiNTER.mkv -y -c:v libx265 -c:a copy XXXXXXX.2014.3D.1080p.BluRay.x264-SPRiNTER.x265.mp4
[18:15] <w00ds> so its re-encoding to x265, copy audio
[18:15] <c_14> It'll take a while".
[18:16] <c_14> You can set the crf to control the quality.
[18:16] <c_14> And look at the fps= in the ffmpeg output to find out the current encoding framerate.
[18:16] <c_14> ie how many frames it's encoding per second
[18:16] <w00ds> frame=10328 fps=6.7 q=0.0 size=  141221kB time=00:07:11.16 bitrate=2683.1kbits/s
[18:17] <w00ds> 4cores @ 4gighz each
[18:17] <w00ds> im guessing its pure CPU power, right?
[18:17] <w00ds> so the more CPU i through at it ... the faster it'll encode?
[18:17] <c_14> yep
[18:17] <w00ds> k
[18:17] <w00ds> after this encoding ... i'll redo the vmware to be 8 cores @ 4gighz
[19:26] <pa> question: why does handbrake generate a mkv output file with cue points every 10 seconds, while ffmpeg generates one with cue points every 4.5 seconds? even if i specify -keyint_min 250
[19:29] <pa> http://paste.ubuntu.com/8419593/
[19:30] <pa> at the end i ctrl-c'ed, like after 800 frames
[19:32] <pa> ok, maybe i'm wrong in fact
[19:32] <c_14> Ok, now what do you mean by "cue points"?
[19:32] <c_14> I-frames?
[19:32] <pa> cue points are 8.4secs spaced
[19:32] <c_14> Which they should be.
[19:32] <pa> that probably means 250frames @29.9fps
[19:33] <JodaZ> can i have ffmpeg not touch audio samples/frames? i have a problem with it splitting audio samples when seeking
[19:34] <c_14> -c:a copy ?
[19:37] <JodaZ> c_14, then you can't seek i think
[19:37] <c_14> You can seek, it just might not be as precise.
[19:37] <JodaZ> hmm
[19:43] <ElAngelo> hi, i have a couple of files ffplay doesn't seem to want to play at all but i think it's related to the video driver
[19:43] <ElAngelo> is that possible?
[19:43] <ElAngelo> and how to confirm this?
[19:44] <ElAngelo> the files are mp42
[19:44] <ElAngelo> and the video driver is r600
[19:44] <ElAngelo> on linux
[19:44] <c_14> ffplay -vn ?
[19:44] <c_14> If that works, ffplay -nodisp
[19:46] <ElAngelo> it says it fails to open audio
[19:46] <ElAngelo> that kind of completely stuns me
[19:46] <c_14> ffplay -an ?
[19:46] <ElAngelo> is that even possible?
[19:47] <c_14> Sure, if you say use alsa without dmix and you already have an audio output open.
[19:47] <ElAngelo> hmm
[19:47] <ElAngelo> right
[19:47] <ElAngelo> ok i'll have to do this differently then
[19:47] <ElAngelo> xbmc is already running as xbmc user and i'm trying to run ffplay as root
[19:47] <ElAngelo> on top of that
[19:48] <ElAngelo> probablby the audio device is assigned to xbmc now
[19:50] <ElAngelo> oh crap
[19:50] <ElAngelo> permission denied if i try to play it as xbmc users
[19:50] <ElAngelo> *user
[19:50] <ElAngelo> it's just the permissions on the file that are wrong
[19:50] <ElAngelo> sigh
[19:50] <ElAngelo> wasted countless hours on this
[19:50] <ElAngelo> thnx c_14
[19:51] <c_14> np
[19:55] <dahat> Are there any known 'newer' RTMP servers that spit out either RTMPE or RTMPS that libRTMP is known not to work with at this time?
[21:42] <MikeJoel> what would be the best pixel format for converting from swf?
[22:05] <asix3> does anyone know how to find out the version of avformat I'm using? I need to write an sdp file and I belive I've got an error in this line: a=tool:libavformat 55.2.100
[22:10] <sacarasc> If you have the ffmpeg binary, run that and it should tell you.
[22:12] <asix3> oh, great
[22:15] <rainey> how does the libavcodec decoder deal with partial audio packets?  Will I have to buffer a full block of say mpeg1 layer 2 audio to pass it to the decoder, or does it have its own internal buffers that I can just pass a bitstream to?
[22:15] <asix3> well, that wasn't the issue. I'm getting this error: Could not find codec parameters for stream 0 (Video: h264): unspecified size Consider increasing the value for the 'analyzeduration' and 'probesize' options
[22:16] <asix3> how can I set analyzeduration and probesize?
[22:17] <roninhack> Hi , i  did build ffmpeg , but i cant enter multiple image in loop , forexample -loop 1 -i image.png -i audio.mp3 -i video.mp4 , im getting error only at image input s ,
[22:17] <Nosomy|off> asix3, the last ffplay have the same problem with matroska files with hevc video stream
[22:17] <roninhack> anyone help me about it? i'm thinking , i miss library or etc?
[22:18] <asix3> here's the sdp file I'm working with, along with a gstreamer pipeline that can pick up the stream: http://pastebin.com/CQLb2PVp
[22:19] <roninhack> im dont streaming
[22:19] <asix3> Nosomy: I don't think I'm using matroska or hevc
[22:20] <asix3> and I'm not using ffplay
[22:20] <Nosomy> ok...
[22:20] <asix3> or am i?
[22:21] <asix3> here's the file I'm working with: http://pastebin.com/AgbtFmmW
[22:22] <Nosomy> only i typed, ffplay reports the same error message when try playback matroska with hevc....
[22:28] <asix3> ok
[22:32] <ebfull> is the raw AVPacket data handed to the muxer of matroska going to be placed within the container without modifications? obviously it'll place metadata around it, but will it change the packet?
[22:32] <MikeJoel> having a hard time finding this in the docs - still images indexed, say 1-50, 100-150, 200-250 - I thought I saw a flag for skipping missing indexes but can't find it now.
[22:32] <c_14> MikeJoel: just glob?
[22:33] <MikeJoel> glob? just a sec will have to read about that.
[22:33] <c_14> https://ffmpeg.org/ffmpeg-formats.html#image2-2
[22:36] <MikeJoel> says globbing is not supported in the build I have
[22:43] <asix3> huzzah -- the problem was that I was specifying the wrong IP. Now I'm getting this error: [h264 @ 0x7fca7b01f200] non-existing PPS 0 referenced [h264 @ 0x7fca7b01f200] non-existing PPS 0 referenced [h264 @ 0x7fca7b01f200] decode_slice_header error [h264 @ 0x7fca7b01f200] no frame! -- any ideas?
[22:44] <c_14> MikeJoel: zeranoe?
[23:07] <MikeJoel> hmmm actually does not appear to be a way. I guess I need to renumber.
[00:00] --- Thu Sep 25 2014


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