[Ffmpeg-devel-irc] ffmpeg.log.20131007

[burek]

[00:36] <MedDev> Hello, I'm trying to record my screen and the output of my sound card at the same time. It works, but only for 20 seconds then the sound cuts out. ffmpeg is ran using this http://pastebin.com/YPcD1Mtm (includes output of ffmpeg).
[00:49] <klaxa> MedDev, i guess your video will also be speed up by factor ~2?
[00:49] <MedDev> klaxa, yes
[00:50] <klaxa> your overall system performance is only able to provide 14 frames per second (just as the log says), either decrease the input framerate to something you know your system can provide, or don't specify it at all and take as many (variable frame rate) frames your system can output
[00:51] <MedDev> ok :)
[03:31] <norbert_> hi, I'm trying to convert a 1920x1040 video to 1920x1080
[03:31] <norbert_> I'm using this command: ffmpeg -r 23.976 -i 1920x1040.mkv -vf scale=1920:1080 -b 4000k -ab 160k -r 60 -acodec libvo_aacenc out.mp4
[03:32] <norbert_> ffmpeg version N-54234-gef90639 Copyright (c) 2000-2013 the FFmpeg developers built on Jun 28 2013 05:12:50 with gcc 4.6 (Debian 4.6.3-1)
[03:32] <norbert_> and I get this error: Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height
[03:32] <norbert_> it also says: [libvo_aacenc @ 0x9d7ba20] Unable to set encoding parameters
[03:32] <norbert_> any ideas/suggestions?
[03:33] <norbert_> somewhat related, I'm also wondering why anyone would create a video that's 1920x1040, seems like really weird dimensions to me
[03:49] <klaxa> norbert_ some people are weird, also if the mkv already has aac audio, why not copy that stream? apart from that the recommended aac encoder is libfdk-aac
[03:53] <norbert_> this appears to work: ffmpeg -r 23.976 -i 1920x1040.mkv -vf scale=1920:1080 -b 4000k -r 60 -acodec copy out.mp4
[03:54] <klaxa> you also shouldn't have to define the input framerate
[03:54] <norbert_> even with -ab 160k it works
[03:54] <norbert_> so basically it didn't accept -acodec libvo_aacenc
[03:54] <norbert_> framerate -> ok
[03:54] <klaxa> mmmhh if you copy the codec it won't apply any bitrate stuff
[03:55] <klaxa> given the framerate is it anime by any chance?
[03:56] <norbert_> not an anime
[03:56] <klaxa> because in that case i'd like to know what group releases in 1920x1040 so i can avoid them if that's not the original resolution
[03:56] <klaxa> ok
[03:56] <norbert_> do you know of any way to preview a .mp4 file before the whole reencoding is finished?
[03:57] <norbert_> totem plays the audio not video, vlc and mplayer do nothing
[03:58] <norbert_> I don't understand your "if you copy the codec it won't apply any bitrate stuff"
[03:58] <norbert_> "-acodec copy" means I copy the audio codec, right?
[03:58] <norbert_> and audio has nothing to do with bitrate stuff
[03:59] <norbert_> I'm going to keep the input bitrate just in case
[04:01] <norbert_> anyways, seems to work fine now
[04:01] <norbert_> will take a couple of days though :P
[04:03] <norbert_> "Aspect Ratio: 1.85 : 1"
[04:03] <norbert_> according to IMDb
[04:03] <norbert_> so apparently that's how it was released
[04:06] <norbert_> "The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1." according to Wikipedia: http://en.wikipedia.org/wiki/Aspect_ratio_%28image%29
[04:07] <norbert_> US widescreen cinema standard
[04:12] <klaxa> <norbert_> and audio has nothing to do with bitrate stuff yeah but if you use -b:a 160k it would be audio bitrate
[04:12] <klaxa> and that doesn't get applied if you use -c:a copy
[04:13] <norbert_> yeah, okay
[10:15] <bouba> hi, someone can help me find a better method to capture regular jpeg thumbs on h264 videos ? "-r 1/20" seems to have behaviors
[10:15] <bouba> pleease
[10:17] <bouba> durandal_1707: no problem with the cli command...but the capture interval is not static
[10:18] <bouba> i guess "-ss" is better to capture
[10:18] <bouba> but i dont know the total lenght of the videos
[10:19] <bouba> THUMBCMD="ffmpeg -y -i $INPUT -an -r 1/20 -f image2 $INPUT_%05d.jpeg"
[10:20] <bouba> ffmpeg sends no error
[10:20] <bouba> and creates the thumbs according to the regex
[10:25] <durandal_1707> replace '-r 1/20' with '-framerate 1/20'
[11:01] <bouba> durandal_1707: -r is not an alias of -framerate ?
[11:01] <durandal_1707> nope
[11:04] <bouba> thx durandal, the behaviour seems different and correct this time
[11:52] <bouba> durandal_1707: "-vf fps=fps=1/20" seems to work better for regular interval capture
[11:53] <bouba> i don't really understand why
[12:00] <durandal_1707> bouba: fps filter drops and dupes random frame to make video cf
[12:00] <durandal_1707> *cfr
[12:01] <bouba> crf ?
[12:01] <durandal_1707> cfr
[12:01] <durandal_1707> constant frame rate
[12:01] <bouba> so the capture won't be at regular interval...
[12:02] <bouba> found here : http://ffmpeg.org/trac/ffmpeg/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video
[19:17] <jure> could someone advise me on how to properly downmix a 5.1 song to a 2ch according to a well-established standard a la dolby digital
[19:17] <jure> with ffmpeg ofc
[19:23] <llogan> do you want just the FL and FR channels, or do you want to combine all channels to their respective L or R channel?
[19:24] <jure> all of them
[19:27] <llogan> does simply using -ac 2 do what you want? (i'm not sure if it adheres to the standard stuff you mentioned)
[19:29] <jure> ffmpeg will probably select only L and R. but I'll try.
[19:32] <durandal_1707> perhaps you need -matrix_encoding?
[19:32] <jure> yeah
[19:33] <jure> so ffmpeg definitely uses more than the L and R channels with -ac 2, but there's also needless attenuation of the signal.
[19:34] <durandal_1707> -matrix_encoding dolby/dplii
[19:34] <jure> now I wish I knew which matrix ffmpeg uses by default.
[19:36] <durandal_1707> also you can mix with different coefficients using audio filters....
[21:07] <StamEhad940> Hi! I have a muxed UDP MPEG-2 multi-program transport stream. How can I used ffmpeg to dump this stream to a .ts file without any transcoding?
[21:16] <StamEhad> Hi! I have a muxed UDP MPEG-2 multi-program transport stream. How can I used ffmpeg to dump this stream to a .ts file without any transcoding?
[21:20] <jure> durandal_1707: how do I tell ffmpeg to phase-shift?
[21:25] <durandal_1707> jure: what you mean by phase-shift?
[21:25] <jure> durandal_1707: see for example http://en.wikipedia.org/wiki/Matrix_decoder#Dolby_Pro_Logic_II_matrix_encoding_.282:5.29
[21:37] <codepython777> how can i fix this :[dshow @ 000000000030e040] Could not find video device. ?
[21:37] <codepython777> am trying this on windows : ./bin/ffmpeg.exe -f dshow -i video="UScreenCapture" output.flv
[22:07] <jure> use BandiCam?
[22:08] <codepython777> ?
[22:08] <codepython777> jure: does it use ffmeg?
[22:09] <jure> no, doesn't need ffmpeg
[22:09] <codepython777> jure: I need a 35 minute recording, and dont want to be monkeying around patching/stitching
[22:09] <codepython777> was hoping to use ffmpeg
[22:09] <jure> well that's great, bandicam will do that job
[22:10] <codepython777> jure: only 10 minutes
[22:10] <relaxed> codepython777: did you look at https://trac.ffmpeg.org/wiki/How%20to%20capture%20a%20webcam%20input
[22:10] <relaxed> wait, that's not right :/
[22:11] <relaxed> https://trac.ffmpeg.org/wiki/How%20to%20grab%20the%20desktop%20%28screen%29%20with%20FFmpeg
[22:11] <codepython777> relaxed: that uses the camera on my laptop, i need to capture the screen
[22:11] <relaxed> yeah, look at the second link
[22:12] <codepython777> relaxed: ffmpeg -f dshow -i video="UScreenCapture" output.flv - gives - how can i fix this :[dshow @ 000000000030e040] Could not find video device. ?
[22:12] <codepython777> (3:37:43 PM) codepython777: am trying this on windows : ./bin/ffmpeg.exe -f d
[22:12] <codepython777> thats where i started and came here
[22:12] <relaxed> did you try listing the devices?
[22:12] <codepython777> no i did not
[22:12] <durandal_1707> than what you wait?
[22:13] <relaxed> do so
[22:13] <codepython777> with what command?
[22:13] <relaxed> maybe it's not "UScreenCapture" for your system
[22:13] <relaxed> read the wiki I just pasted
[22:14] <codepython777> http://bpaste.net/show/U2MtCuW4L7H0Et8X7nM1/ - here is the list
[22:14] <codepython777> how do i capture my screen and speakers to an flv/mp4?
[22:15] <durandal_1707> perhaps you instally some capturer that export itself via dshow ...
[22:16] <codepython777> I need to ?
[22:17] <codepython777> no hope without that?
[22:20] <fazias> http://obsproject.com/ (you can just save to file instead of stream)
[22:20] <fazias> on windows*
[22:21] <codepython777> fazias: have you used it on windows? mp4 outut?
[22:22] <fazias> yes
[22:22] <fazias> you can also fully customize the x264 cmd line parameters if you feel like it, just need to disable some stuff
[22:25] <codepython777> fazias: could not initialize directX
[22:25] <codepython777> error -> Close
[22:26] <fazias> :D
[22:26] <fazias> good luck then
[22:26] <codepython777> lol
[22:31] <GoaLitiuM> codepython777: are you trying to use 64-bit binaries of ffmpeg with UScreenCapture?
[22:31] <GoaLitiuM> if the filter is 32-bit only, then you need to use 32-bit ffmpeg
[22:34] <codepython777> GoaLitiuM: I downloaded the 64-bit binaries for windos
[22:34] <codepython777> how do i figure out what filter  bit i am using?
[22:34] <GoaLitiuM> then try downloading 32-bit ffmpeg binaries
[22:34] <GoaLitiuM> i'm fairly sure most directshow devices only have 32-bit version available
[22:36] <codepython777> ic
[22:36] <codepython777> http://ffmpeg.zeranoe.com/builds/
[22:39] <codepython777> GoaLitiuM: http://bpaste.net/show/c5q9AB6WsWHw4YzYhIlk/
[22:39] <GoaLitiuM> which one is that
[22:40] <codepython777> output of this - > ffmpeg -list_devices true -f dshow -i dummy
[22:40] <codepython777> downloaded the 32- bit
[22:40] <codepython777> static one- top
[22:40] <GoaLitiuM> have you installed uscreencapture?
[22:41] <codepython777> nope
[22:41] <GoaLitiuM> well there you have it
[22:41] <GoaLitiuM> http://www.videohelp.com/tools/UScreenCapture
[22:41] <codepython777> downloading now
[22:42] <GoaLitiuM> OBS didn't work?
[22:43] <codepython777> GoaLitiuM: Nope
[22:43] <codepython777> GoaLitiuM: how do i capture the speakers to the mp4?
[22:43] <codepython777> ./ffmpeg.exe -f dshow -i video="UScreenCapture":audio="Microphone" output.mp4
[22:43] <codepython777> video=UScreenCapture:audio=Microphone: Input/output error
[22:44] <codepython777> seems like the screen will get captured with UScreenCapture
[22:45] <GoaLitiuM> i recommend using fraps or dxtory if you want to capture both screen and audio too
[22:45] <codepython777> GoaLitiuM: will any of them work for a 35 minute recording without paying?
[22:46] <GoaLitiuM> nope :/
[22:46] <codepython777> so how do i do audio ith ffmpeg?
[22:46] <GoaLitiuM> next best option would be OBS/FFsplit/free version of Xsplit, and only record locally
[22:47] <codepython777> obs didnt work
[22:47] <GoaLitiuM> how old hardware you have on your system?
[22:47] <GoaLitiuM> OBS requires DX10 support
[22:48] <codepython777> this is a 2 year old laptop
[22:55] <relaxed> codepython777: are you using the most recent version of ffmpeg? http://ffmpeg.zeranoe.com/builds/
[22:55] <codepython777> yes
[22:56] <codepython777> tried both 32 and 64 bit - GoaLitiuM's help = screen capture possible it seems
[22:56] <codepython777> but i need to capture speakers as well
[22:56] <GoaLitiuM> perhaps with this: http://sourceforge.net/projects/virtualaudiodev/
[00:00] --- Tue Oct  8 2013