[Ffmpeg-devel-irc] ffmpeg.log.20140202

[burek]

[05:37] <OODavo> I'm downloading 1080p video using youtube-dl, and it comes as separate video and audio files. Apparently they're supposed to be merge-able by doing "ffmpeg -i audio.m4a -i video.mp4 -acodec copy -vcodec copy out.mp4", but the resultant file I get only has the audio and no video. What am I doing wrong?
[05:38] <OODavo> Note that youtube-dl itself has support for merging DASH video using ffmpeg, and the file it produced had exactly the same problem, so I assume there are issues with my ffmpeg setup.
[05:39] <OODavo> (I have the Raring package from https://launchpad.net/~jon-severinsson/+archive/ffmpeg installed.)
[05:40] <OODavo> The same problem came up with the "normal" Raring ffmpeg package  the dumb one that tells you ffmpeg is obsolete relative to avconv  however.
[05:42] <Maverick|MSG> anyone know the default pix_fmt that libx264 will output an mp4 with?  I can't seem to find it in the documentation
[05:45] <Maverick|MSG> nevermind, I think it is yuvj444p
[07:07] <anshul_> can any one explain static void clip_interval(int wmax, int *x, int *w, int *dx) what does the parameter means over here
[07:09] <anshul_> there is one line explaing parameters which is " Clip interval [x; x+w[ within [0; wmax[. "  , I am unable to understand any thing from that line
[07:27] <OODavo> https://github.com/rg3/youtube-dl/issues/1809 is the specific problem I'm having, except that I'm using an actual ffmpeg build rather than an avconv one.
[09:07] <znf> Hello.
[09:08] <znf> Would ffmpeg be capable of drawing (or moving) a line based on the progress of the video being generated? Let's say I have a single frame, frame.png which I want to combine with a video. now, could there be a way to generate some sort of "virtual" progress bar over the video? from 0% to 100% ?
[09:26] <llogan> znf: maybe you could use an expression for x and/or y using overlay filter
[09:26] <llogan> http://ffmpeg.org/ffmpeg-filters.html#overlay
[09:26] <llogan> "sliding overlay" example may help
[09:26] <llogan> also http://ffmpeg.org/ffmpeg-utils.html#Expression-Evaluation
[09:30] <znf> llogan, indeed! thanks for the pointer
[09:30] <znf> I'll try to see if I can manage
[10:37] <znf> llogan, I don't really understand how to run that filter. I get: Cannot find a matching stream for unlabeled input pad 1 on filter Parsed_overlay_0
[10:37] <znf> :-/
[11:16] <heyffmpef> hello can you point me to recent examples on libavcodec, especially how to record/encode/ audio, cause what i found on http://www.ffmpeg.org/doxygen/2.1/channel__layout_8h_source.html is out of date
[13:28] <znf> Maybe someone has an idea here, too: http://stackoverflow.com/questions/21510521/ffmpeg-move-a-slider-image-over-a-background-from-0-to-100-in-sync-with-t
[13:54] <ndrei_> Hello! I'm setting up a script to record my desktop, using a USB mic as audio device (via ALSA). It works great on its own, but when I add a webcam overlay, I get no sound. I'm currently reading the docs, and have managed to get it working via PulseAudio, but I'd rather not use Pulse and understand why it's not working with Alsa.
[13:54] <ndrei_> here's what I'm using: ffmpeg -f alsa -ac 1 -ar 48000 -i usb -f x11grab -s 1366x768 -r 10 -i :0.0+$offset -vf "webcam=/dev/video0:f=video4linux2, scale=400:-1, fps, setpts=PTS-STARTPTS [webcam] ; [in][webcam] overlay=main_w-overlay_w-20:main_h-overlay_h-20 [out]" -acodec pcm_s16le -vcodec libx264 -preset ultrafast -crf $quality -threads 0 -af volume=$mic_gain $filepath
[14:09] <ndrei_> Okay, reading the manpage this probably has something to do with stream selection. Will look into that, but I'd still appreciate help :).
[14:12] <foobarbaz> hi
[14:37] <znf> another question about filters - ffmpeg -loop 1 -r 25 -t 00:03:26.29 -i video.png -loop 1 -r 25 -i progress.png -filter_complex "overlay=eval=frame:x='if(gte(n,0), -W+(n)*0.24854368932, NAN)':y=H-h" -i video.mp3 -acodec copy video.mp4 - why wouldn't this evaluate on every frame? rather it seems to evaluate every second, instead of moving my overlay every frame by 0.24pixels, it moves it every second by ~6 pixels
[17:15] <znf> Is there any way to read id3 tags with ffmpeg and use them in a drawtext filter?
[17:22] <anshul_> you can do it with libav but ffmpeg does not allow you would not be able to do that
[17:22] <znf> that's sad :(
[18:01] <relaxed> znf: aren't they displayed when you run ffmpeg -i on it?
[18:02] <znf> relaxed, they are, how's that going to help me? :)
[18:02] <znf> I thought ffmpeg could do something smart like -filter_complex 'drawtext=text="%artist - %title"'
[18:03] <relaxed> you could use awk and some scripting
[18:03] <znf> I know I could :)
[18:03] <znf> I was hoping to do it all in ffmpeg
[18:03] <relaxed> your hopes have been crushed
[18:04] <relaxed> I bet awk + the libass filter would be best if you have to script it.
[18:05] <znf> there's tons of options if I have to do it outside ffmpeg :)
[18:05] <relaxed> indeed
[18:05] <znf> now, while I got someone's attention
[18:06] <znf> http://pastebin.com/bSBiwcLS <-- why does my overlay animation move 2 pixels every few frames instead of 0.24 pixels every frame like it should? :)
[18:06] <relaxed> znf: you should file a feature request on that.
[18:35] <c0nio> hi, is it possible to stream a directshow device encoded in libvpx to an udp port?
[18:36] <c0nio> i got mpeg2 video working fine but had no luck with libvpx
[18:42] <c0nio> Hello71: http://pastie.org/private/iko6hhv15632lv2bie6zla
[18:42] <c0nio> i'm using those commands
[18:42] <Hello71> and the output?
[18:43] <c0nio> http://pastie.org/private/om8wgq9hbqqumgsa1rhyna
[18:44] <Hello71> so... what's the issue?
[18:45] <c0nio> i cant receive an image using ffplay
[18:45] <znf> what does ffplay say?
[18:45] <c0nio> nothing really just standard output, it just behaves like its not receiving any data
[18:48] <relaxed> c0nio: -f webm
[18:49] <c0nio> relaxed: same result in ffplay
[18:51] <znf> http://stackoverflow.com/questions/18815092/webm-local-udp-streaming-using-ffmpeg <-- this guy also tried it
[18:52] <c0nio> yea i saw that post
[18:57] <relaxed> works over tcp
[18:57] <relaxed> -f webm 'tcp://localhost:6001?listen'
[18:58] <c0nio> for streaming?
[19:00] <c0nio> it switches to Stream #0:0: Video: rawvideo, bgr24, 640x480, 16 tbr, 10000k tbn, 16 tbc and just drops frames
[19:01] <znf> If you have a video.file that is at 25fps and 1 minute long, can you properly extend it to 3-4-5 minutes while overlaying on top of another video, but keeping it at 25fps?
[19:01] <znf> (and I probably don't make much sense now after 26 hours awake)
[19:19] <Fohlen> anyone knows about youtube playback files?
[19:20] <Fohlen> somehow I can convert them with ffmpeg to mp4 (which takes AGES) and then to mp3, but not directly
[19:20] <Fohlen> Output file #0 does not contain any stream
[19:21] <Fohlen> sure, second
[19:24] <Fohlen> http://pastebin.com/r42d1DP3
[19:25] <Fohlen> I verified that libmp3lame is installed, and it works converting mp4 to mp3
[19:25] <znf> What's with all the inconsistencies between ffmpeg versions and the manual? :-/ the filters page mentions -ovs and some stuff that my ffmpge doesn't have :(
[19:25] <Fohlen> converting to mp4 is very slow, dunno if I could speed that up
[19:25] <Fohlen> @relaxed
[19:26] <Fohlen> doesn't need to be best quality
[19:26] <znf> Fohlen, -preset ultrafast
[19:26] <Mavrik> znf, the manual is consistent.
[19:26] <Mavrik> you probably have ancient ffmpeg.
[19:26] <znf> ffmpeg version N-60087-g94a5241 Copyright (c) 2000-2014 the FFmpeg developers
[19:26] <znf> I wouldn't call that ancient :-/
[19:27] <Mavrik> Fohlen, you're using libav not ffmpeg.
[19:27] <Fohlen> znf, still that only gives me 1mb in 1 minute o.o
[19:27] <Fohlen> Mavrik, I installed ffmpeg
[19:27] <Fohlen> dunno what ubuntu package manager does
[19:27] <Fohlen> :(
[19:27] <znf> ubuntu has switch ffmpeg to avconv
[19:27] <Mavrik> well, it doesn't intall ffmpeg
[19:28] <znf> (which is yet another confusing thing!)
[19:28] <Fohlen> sorry for the inconvience then, is #avconv the better place to ask then?
[19:28] <znf> I don't think there's an #avconv channel
[19:29] <Mavrik> #libav.
[19:29] <Fohlen> znf, is there a different, for me the programm behaves exactly the same o.o?
[19:29] <Fohlen> thx
[19:29] <znf> Fohlen, it's different, yes
[19:29] <Fohlen> I dunno, never read the ffmpeg source
[19:29] <Fohlen> okay, thx :)(
[19:29] <Mavrik> znf, hmm, that's wierd then, you shouldn't be seening differences
[19:29] <znf> ffmpeg on ubuntu is just a wrapper for avconv these days
[19:29] <Mavrik> I'm just not sure if Doc is built from master or from latest stale
[19:30] <Mavrik> *stable
[19:30] <Fohlen> is that good or bad?
[19:30] <znf> I don't have drawtext=border for example :-/
[19:30] <Mavrik> Fohlen, it's old which is the bigger problem
[19:30] <znf> maybe my build is not compiled with those features *sigh*
[19:30] <Fohlen> why did they switched off then?
[19:30] <Fohlen> More convient, more stable?
[19:31] <znf> one would say consistency, but it' far from that :P
[19:31] <Mavrik> Fohlen, because Ubuntu maintainer was politically on the other side of the fork.
[19:31] <Mavrik> Debian more exactly.
[19:31] <Fohlen> does the fork feature up any advantages?
[19:32] <znf> just confusion and mayhem
[19:32] <Fohlen> hmm
[19:32] <Fohlen> sounds prety shit
[19:33] <Fohlen> maybe I'll self-compile ffmpeg, thx for the infos! :)
[19:33] <Mavrik> Fohlen, there are static buidls
[19:33] <Mavrik> which you just download and run
[19:33] <znf> I'd suggest getting a static build, rather
[19:33] <Fohlen> why so?
[19:33] Action: Fohlen likes having a look on the structure of software he uses
[19:33] <Fohlen> :)
[19:34] <znf> ffmpeg is not that easy to compile and meet its dependencies, for my own experience
[19:34] <znf> it's a huge project :)
[19:34] <Fohlen> oki
[19:35] <c0nio> Fohlen: i cross compiled an LGPL version for work, took me about 4 days to figure everything out. not worth the hassle if you dont get money ;)
[19:36] <Fohlen> 4 days?
[19:36] <Fohlen> seems like someone missed the autogen
[19:36] <Fohlen> :D
[19:36] <znf> hmm, weren't there quite a few windows builds of ffmpeg? I can't find any with --enable-libopencv
[19:36] <c0nio> cross compiling on linux for win32 libs
[19:37] <Fohlen> c0nio, mingw is a whore
[19:37] <Fohlen> writing cross-software is a shity task
[19:37] <Fohlen> we should just abadone windows
[19:37] <Fohlen> that'd be fine
[19:37] <c0nio> yes, but people who buy the software won't :)
[19:38] <Fohlen> c0nio, give it one or 2 years
[19:38] <Fohlen> :P
[19:38] <Fohlen> even government switches off linux nowadays
[19:38] <Fohlen> ;)
[19:38] <Fohlen> business changed the last years
[19:38] <Fohlen> open-source is getting trendy
[19:38] <Fohlen> :)
[19:41] <Fohlen> anyway thx guys, I'll try my luck in #libav
[19:43] <znf> Fohlen, ffmpeg -i input -acodec copy -vcodec copy file.mp4
[19:43] <znf> for youtube videos
[19:45] <Hello71> or delete a and v
[19:48] <znf> that too
[19:49] <brontosaurusrex> how do i use replaygain filter, an example?
[19:56] <znf> does yuva420p have an alpha channel?
[20:03] <Mavrik> znf, yes, hence the "a" :)
[20:03] <znf> was making sure :)
[20:34] <znf> let' say I have 2 videos, one is 1 minute long, the other is 3-4 minutes long. I want to overlay the short one over the long one, while having both end at the same time. How would I do that?
[20:34] <Mavrik> ugh
[20:35] <Mavrik> how would that look?
[20:38] <znf> Mavrik, the 2nd video would be in a small corner :)
[20:38] <Mavrik> no
[20:39] <znf> uhm?
[20:39] <Mavrik> how do you expect a 1 minute to play for 4 minutes?
[20:39] <znf> re...sample or something?
[20:39] <Mavrik> of what?
[20:39] <Mavrik> do you want a loop?
[20:39] <Mavrik> do you want a slow-motion recording?
[20:39] <znf> no, I don't want a loop
[20:39] <Mavrik> do you want a duplicated video?
[20:39] <znf> I want some sort of timeshift
[20:40] <znf> the 2nd (short) video is just a non-descript animation, more like a mask for the 2nd one
[20:40] <znf> so I don't care about the timing on that
[20:41] <znf> except they both have to start at the same time and end at the same time :)
[21:04] <llogan> everyone is confused
[21:04] <llogan> see "shortest" option in the overlay filter
[21:05] <llogan> i guess
[21:24] <brontosaurusrex> znf, no, you don't want that.
[21:24] <znf> brontosaurusrex, why not? :(
[21:24] <znf> I want that
[21:25] <brontosaurusrex> define the 2nd clip as nicely loopable and then work on from there
[21:26] <brontosaurusrex> slo-mo is always a bad choice
[21:26] <brontosaurusrex> especially when overlayed into non-slomo clip
[21:30] <znf> which part of can't loop didn't he understand? :-/
[21:32] <znf> Hmmm. I don't get it.
[21:33] <znf> I create a yuva420p webm file, but when I do ffmpeg -i I get yuv420 :-/
[21:50] <fraktor> I'm trying to cut a video with frame precision.
[21:51] <fraktor> as far as I can tell though, it only goes to fractions of a second.
[21:51] <fraktor> can I enter a frame number and have ffmpeg cut that?
[21:52] <fraktor> or
[21:53] <fraktor> alternatively, how can I make frame%04.png match when the numbers start at frame0230.png?
[21:56] <znf> fraktor, -dframes ## ?
[21:57] <znf> ffmpeg -i input -t 00:30:00 -dframes 15 frame%04.png
[21:57] <fraktor> the problem that I'm having is that I need to record two video files.
[21:57] <fraktor> one is frames 0 to 229
[21:57] <fraktor> the other is frames 230 to 308.
[21:58] <fraktor> and when I split the video into png frames, and separate the two, I can encode frames 0 to 229, but I can't encode frames 230 to 308.
[21:59] <fraktor> frame%04d.png doesn't work when it doesn't start at 0, and frame*.png just generates a video file with one frame.
[23:23] <freezway> so I'm working on a music sorting program using libavformat. I'm trying to make it ignore non-music files, including video. This is currently implemented as checking if it has a audio stream but not a video stream. Unfortunately some songs have their album art as a video stream. Any ideas on how to resovle this?
[23:24] <JEEB> there's IIRC a composition flag for that
[23:25] <freezway> where?
[23:26] <JEEB> AV_DISPOSITION_ATTACHED_PIC
[23:26] <JEEB> seems to be the flag
[23:27] <JEEB> a stream has a member called disposition
[23:27] <JEEB> you can check that & AV_DISPOSITION_ATTACHED_PIC
[23:27] <JEEB> if that is true, then it's an attached pic
[00:00] --- Mon Feb  3 2014