[Ffmpeg-devel-irc] ffmpeg.log.20140914

burek burek021 at gmail.com
Mon Sep 15 02:05:01 CEST 2014


[02:04] <nsfx> Hello, any tips on how to avoid blurry/pixelated text on the x11grab source in this script? http://pastebin.com/HTnRGpSs
[02:18] <EvolE> nsfx: did you try to increase bitrate of the video "-b:v 1000k -minrate 1000k -maxrate 1000k" ? you can try 2000, 2500 and 3000 and see if it helps
[02:19] <nsfx> EvolE: I have, doesn't seem to make a difference. I also tried using a beefier pixel format
[02:20] <nsfx> I think it's something in the filter_complex causing this because if I work with just the x11grab source it looks fine
[02:21] <EvolE> nsfx: is "inkject" your twitch channel?
[02:22] <nsfx> EvolE: Yes
[02:22] <sacarasc> nsfx: Also, avconv is not supported in this channel. Try #libav.
[02:23] <nsfx> sacarasc: I figured I'd x-post here :) more populated
[02:23] <nsfx> Sorry about that
[02:28] <_dunno_> nsfx have u tried different presets?
[02:30] <nsfx> _dunno_: Yes I've tweaked just about everything outside the filter_complex param
[02:30] <nsfx> Looks the same even on veryslow
[02:30] <nsfx> Here's what the output looks like to get an idea http://i.imgur.com/RSL3NcC.png
[02:31] <sacarasc> nsfx: You're doing 30 images at 1280x720 within 125kB. They're not gonna look good! (And Twitch supports 3k.)
[02:33] <_dunno_> nsfx take a screenshot and zoom in - guess it'll look the same - it's your X11 not ffmpeg/avconv
[02:34] <_dunno_> nsfx -vf unsharp might help
[02:35] <EvolE> nsfx: and seems like something is wrong with colors on the video?
[02:35] <nsfx> sacarasc: When I stream my entire desktop it looks way sharper, this aliasing/color loss only happens when I mix video sources
[02:36] <nsfx> _dunno_: Sorry I didn't get what you meant. What do you mean by zooming in / X11's fault?
[02:36] <EvolE> so probably something wrong is in "-filter_complex" parameter
[02:36] <sacarasc> Waiting for OBS Multiplatform, then. :D
[02:37] <nsfx> I suppose I can running the equivalent cmmand through ffmpeg proper
[02:37] <nsfx> can try*
[02:38] <EvolE> if you can upload 3 different normal videos I can try to play with them xD
[02:38] <sacarasc> nsfx: ^ Won#t have to install with them.
[02:38] <nsfx> Thanks sacarasc, I'll try that
[02:42] <nsfx> Ah I just fixed it
[02:42] <nsfx> I had a feeling this would fix it
[02:43] <nsfx> Instead of overlaying the x11grab onto the v4l source, I overlayed the v4l source on the x11grab
[02:43] <nsfx> Now it looks great
[02:44] <_dunno_> nsfx so plz post another pic for the before-after experience
[02:44] <nsfx> 1 sec
[02:47] <nsfx> _dunno_: http://i.imgur.com/0pXC7c0.png
[02:50] <EvolE> nice
[02:51] <_dunno_> ? am i blind? differences are marginal - at best
[02:52] <nsfx> _dunno_: -g 60 -keyint_min 30 -b:v 1000k -minrate 1000k -maxrate 1000k \
[02:53] <nsfx> -pix_fmt yuv420p -preset ultrafast -tune film \
[02:53] <nsfx> Oops wrong paste
[02:53] <nsfx> _dunno_: The window on the right is the video output, the window in the middle is the actual window
[02:55] <EvolE> _dunno_: you need to look at the top right corner, on previous screenshot there were almost no colors on that scroreboard
[02:57] <_dunno_> okay i can see the diff there
[02:58] <_dunno_> nsfx OT: NES like Nintendo? gng - ghouls and goblins?
[03:01] <nsfx> _dunno_: Yeap
[03:03] <_dunno_> nsfx don't you think 1280x768 is way to small for NES streaming? Considered using 4k, yet? ;)
[03:04] <nsfx> Hahaha
[06:08] <Soul_keeper> ffmpeg -i input -c:a libvorbis -b:a 192k -vn -sn output.oga      Is the default behavior here CBR or ABR for the audio ?
[06:14] <Soul_keeper> "Set bitrate expressed in bits/s for ABR."  ok found it in the docs, nm
[06:16] <bencc1> to record audio on a server I need a dummy alsa soundcard?
[09:15] <mozzarella> guys help
[09:27] <mozzarella> I'm trying to stream a video to twitch.tv
[12:18] <hachi> hello folks, I'm getting Non-monotonous DTS in output stream with -vsync cfr... and without as well. Does anyone know why -vsync cfr doesn't seem to help that situation?
[13:17] <xtruder> hi/ Does ffmpeg support multi bitrate streaming like FME?
[15:51] <pa> can i somehow tell ffmpeg (via command line/api) to start decoding(or transcoding) from the  nth keyframe, instead of time offset?
[16:49] <brontosaurusrex> what would be equal to : lame -V 2 ?
[19:57] <Belliash> hello
[19:57] <Belliash> I got problem while pushing stream to rtmp server... my stream looses audio
[19:59] <mozzarella> Belliash: how do you do that
[20:00] <mozzarella> I tried to push a video to a rtmp server and failed miserably
[20:01] <EvolE> how you both do that?)
[20:02] <mozzarella> EvolE: no YOU tell us how to do it
[20:02] <EvolE> -f flv rtmp://... ?
[20:03] <mozzarella> ffmpeg -i TEDxGE2014_Stallman05_HQ.ogg -f flv rtmp://live.twitch.tv/app/live_privatezzzzzzzzzzzzzzzzzzzz
[20:03] <mozzarella> but it doesn't work
[20:03] <mozzarella> "Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input"
[20:06] <EvolE> well it can't read the file then, not write to rtmp
[20:06] <EvolE> can you give me TEDxGE2014_Stallman05_HQ.ogg or it's too big?
[20:07] <EvolE> i would like to try that
[20:09] <Belliash> cvlc http://A.B.C.D/stream :sout="#transcode{acodec=mpga,ab=128,channels=2,samplerate=44100}:duplicate{dst=std{access=file,mux=flv,dst=-}}" | ffmpeg -i - -vcodec copy -acodec copy -f flv rtmp://A.B.C.D/stream
[20:09] <Belliash> when i pipe it to VLC its working
[20:09] <Belliash> looks like ffmpeg breaks audio
[20:10] <mozzarella> EvolE: http://audio-video.gnu.org/video/TEDxGE2014_Stallman05_HQ.ogg
[20:10] <EvolE> mozzarella: thx, will try that when after download
[20:11] <mozzarella> I can watch it just fine with totem, so I don't think it's corrupt or anything like that
[20:12] <EvolE> Belliash: try to set codec to aac or mp3 at least
[20:12] <Belliash> ffmpeg -i - -vcodec copy -acodec mp3 -ac 2 -ab 128000 -ar 44100 -strict experimental -f flv
[20:12] <Belliash> also not working
[20:13] <EvolE> mozzarella: is there a torrent of that, speed is 300 kB/sec (
[20:13] <Belliash> when connecting to RTMP, vlc says audio uses undf codec
[20:14] <mozzarella> EvolE: maybe I can upload it on a faster server? we'd need to find one first
[20:15] <EvolE> Belliash: why vlc should say anything if it only sends it to ffmpeg?
[20:15] <Belliash> EvolE: I can open another copy of VLC and connect to RTMP
[20:16] <Belliash> then it says audio codec is undf
[20:16] <Belliash> but when i do cvlc .... | vlc -
[20:16] <Belliash> audio works pretty fine
[20:18] <EvolE> did you try to mux in ts on input vlc ?
[20:18] <EvolE> Belliash:
[20:19] <Belliash> EvolE: yes
[20:19] <Belliash> no difference
[20:20] <EvolE> Belliash: is that input stream is on internet or it's local? can i try it?
[20:21] <Belliash> EvolE: its local
[20:21] <Belliash> do you need any information about it?
[20:26] <EvolE> Belliash: just tried to stream with ffmpeg from file to twitch and it works
[20:29] <EvolE> Belliash: aac and mp3 works for me
[20:30] <EvolE> Belliash: have some lags, but im not sure why..
[20:31] <EvolE> Belliash: why don't you get input stream with ffmpeg?
[20:33] <mozzarella> EvolE: does it work on your end?
[20:34] <EvolE> Belliash: 3 min left for that file...
[20:34] <EvolE> mozzarella:
[20:34] <EvolE> oops)
[20:41] <LiohAu> hey guys, I would like to understand one thing, is ffmpeg using x264? or is it using its own h264 codec ?
[20:41] <LiohAu> or both are valid answers?
[20:41] <JEEB> x264 is the only H.264 encoder available via libavcodec
[20:42] <JEEB> but the decoder is an internal libavcodec one, and x264 has no decoders
[20:43] <EvolE> mozzarella: you need to encode that video to h264 and audio to aac or mp3 to send it to twitch
[20:43] <LiohAu> JEEB: I have a library that has a USE_X264 define, that is based on this: $(shell [ -f $(SYSROOT)/include/x264.h ] || [ -f $(SYSROOT)/local/include/x264.h ] || [ -f $(SYSROOT_ALT)/include/x264.h ])
[20:43] <LiohAu> the thing I don't understand, is that eitheir the library use x264, or it uses ffmpeg
[20:44] <JEEB> x264.h is provided by x264
[20:45] <mozzarella> EvolE: how do I change it to h264?
[20:45] <LiohAu> ok, so I understand the define, but why is this define used to make a choice between x264 vs ffmpeg since ffmpeg rely on x264 ?
[20:45] <JEEB> please ask an esper
[20:46] <JEEB> because I have no fucking idea about what the fuck you are talking about, you might just fucking go poke the people who made whatever you're trying to use
[20:46] <EvolE> mozzarella: use "-vcodec libx264" in ffmpeg command line
[20:47] <LiohAu> JEEB: nevermind
[20:54] <mozzarella> EvolE: how can I pause, rewind, etc.?
[20:54] <mozzarella> I'd like to be able to do that
[20:55] <Belliash> why passing -vcodec h264 makes ffmpeg reencoding video which is already encoded using h264?
[20:56] <JEEB> because you are specifically telling it to re-encode
[20:56] <JEEB> everything else but -c:v (or -vcodec) copy will re-encode the video
[20:57] <Belliash> can i somehow tell it to reencode only if source codec is different?
[20:57] <JEEB> no
[20:58] <JEEB> you will have to do a pass with either ffmpeg or ffprobe to see what the video track is
[20:58] <JEEB> and then decide to either re-encode it or not
[21:00] <foonix> btw, could someone look/test the 2.4 version for getting pixel format from source when using -probesize max?
[21:04] <EvolE> mozzarella: if you want to rewind it while streaming live you better stream the screen and the video player on it)
[21:06] <mozzarella> EvolE: (  ;____;)
[21:07] <mozzarella> can I at least pause it?
[21:09] <EvolE> mozzarella: and what will go to the stream if you pause it?
[21:10] <mozzarella> EvolE: a still image
[21:10] <EvolE> im not sure you can do it with ffmpeg) why not to stream with obs or stream full screen?
[21:11] <mozzarella> EvolE: what's obs?
[21:12] <EvolE> mozzarella: free streaming program on windows
[21:12] <sacarasc> And OS X.
[21:13] <mozzarella> EvolE: I use linux
[21:17] <EvolE> mozzarella: then stream your screen with ffmpeg
[21:17] <mozzarella> EvolE: how?
[21:18] <EvolE> mozzarella: here is some sample script the guy showed yesterday: http://pastebin.com/HTnRGpSs you can take parameters from it probably
[21:20] <xtruder> iam trying to send multiple bitrate/resolution streams to rtmp server, just like FME does (rtmp:.../streamkey1, rtmp:.../streamkey2), however server recognizes only one. Any idea why? (working fine with fme)
[21:26] <EvolE> xtruder: how you doing that?
[21:30] <xtruder> EvolE: ffmpeg -analyzeduration 10M -probesize 10M -re -i rtmp://url -c:a copy -c:v h264 settings -f flv "rtmp://key1" -c:a copy -c:v h264 settings -f flv "rtmp://key2"
[21:31] <xtruder> tried forcing keyframes too, no effect
[21:37] <mozzarella> EvolE: does it track the window? what if I move it around?
[21:39] <EvolE> mozzarella: don't know, i didn't try that script
[21:40] <dada__> hi there. would anyone know if it's possible to make a video containing h264 and flac? I tried the following https://dpaste.de/G0Es
[21:40] <c_14> You can't put flac in mp4.
[21:41] <dada__> would it work if I switched to mkv?
[21:41] <c_14> yep
[21:41] <dada__> thanks I'm gonna have a look to see which arguments I need to use for that
[21:42] <dada__> this is for upload to youtube in a script so I can always just re-encode it but I'd prefer to copy it so that it's faster :)
[21:43] <dada__> looks like I can just set out to tmp.mkv instead of tmp.mp4 and it works
[22:04] <brontosaurusrex> dada__: you could use alac with mp4 i think
[22:13] <dada__> whoops, changing output to .mkv actually broke all videos apparently
[22:13] <dada__> now youtube can't process them
[22:13] <dada__> brontosaurusrex: that's a nice idea, I'll try it
[22:41] <rickbol> been successfully using MP4Box to concatenate 2 ffmpeg generated mp4 files together into a single mp4 file. Is there a way I can concatenate using ffmpeg?
[22:42] <sacarasc> The concat filter might be able to do it.
[22:49] <nicolas_> hello everyone , i would have a question, i want to convert a video track of an mkv file and leave everything else as it is (audiotrack, chaptermarks etc), this has to be agnotic of the input file (the number of auditracks changesfrom file to file ), has anyone an idea how i can achieve this ?
[22:51] <rickbol> nicolas_: are you still storing into an mkv container?
[22:54] <rickbol> sacarasc: I'm running an older version of ffmpeg (0.7.15).    ffmpeg -filters   doesn't list a "concat" filter.
[22:54] <sacarasc> rickbol: Upgrade.
[22:55] <sacarasc> Use one of them if you have to. :D
[22:55] <nicolas_> rickbol: yes, old.mkv has an mpeg2 video track, and new.mkv should have everything the same but with an h264 video track
[22:55] <dada__> would anyone know why the -t argument seems to be ignored here? https://dpaste.de/W2ea#L26,41
[22:56] <sacarasc> dada__: Try using it as an output option.
[22:57] <rickbol> nicolas_: I'm using an old ffmpe, so I expect that the syntax I know wouldn't e correct for a current ffmpeg, but the audio  is copied with   -acodec copy
[22:58] <rickbol> nicolas_: I don't know tje syntax to copy chaptermarks, etc.
[23:03] <dada__> sacarasc: thanks
[23:09] <rickbol> sacarasc: just downloaded the current static build, and   ffmpeg -filters  doesn't list a "concat" switch either.
[23:10] <sacarasc> http://ffmpeg.org/ffmpeg-all.html#concat-3
[23:12] <rickbol> sacarasc: my bad!  I printed the system version, not the new static build.  :-/
[23:14] <Belliash> hey again
[23:14] <Belliash> I got one more question... can I force ffmpeg to keep all audio tracks?
[00:00] --- Mon Sep 15 2014


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