[Ffmpeg-devel-irc] ffmpeg.log.20140106

[burek]

[01:17] <average_> is it possible to give ffmpeg an entire text file to render it ?
[01:17] <average_> with drawtext
[01:18] <average_> or do I have to write some thing of my own to put the lines at the positions they have to be ?
[01:21] <relaxed> hmm, maybe a heredoc or $'blah\nderp\n' would work?
[01:21] <lkiesow> average_: Never done this and I'm don't now what exactly you want to do but you could create a subtitle file and burn it into the video: http://trac.ffmpeg.org/wiki/How%20to%20burn%20subtitles%20into%20the%20video
[01:22] <relaxed> maybe a transparent png of the text overlayed?
[01:23] <relaxed> yeah, hardsubing ssa subs might be more flexible
[06:48] <NeilioC> hi everyone, i've a question about odd behaviour i'm seeing outputting multiple frame images from a video
[10:23] <MTRX2010> hello
[10:23] <MTRX2010> been fighting with my media player for about a week now,  working on my hardware acceloration issues.
[10:24] <MTRX2010> if im using nv12 does that mean im using dxva??
[10:24] <MTRX2010> oO
[14:41] <gomb1729> hello, guys, does a channel for question similar to libav-user exists?
[14:47] <average> hey
[14:47] <average> how do I fade out to a certain volume with afade ?
[15:00] <average> any ideas ?
[15:12] <average> is there a name for the stuff that happens in podcasts when the music starts playing, then it fades out(but not completely) to make room for the voice of the guy that does the podcast ?
[16:11] <average> how do I get a video of an audio equalizer ?
[16:13] <ubitux> you can probably do something with volume filter
[16:13] <ubitux> not sure if we have the eval in it yet
[16:13] <ubitux> for changing it over time
[16:13] <ubitux> mmh maybe another filter was submitted for this
[16:13] <ubitux> aeval
[16:14] <ubitux> http://ffmpeg.org/ffmpeg-filters.html#aeval
[16:14] <ubitux> maybe
[16:15] <average> ubitux: I'm gonna try this out, can you walk me through this ?
[16:15] <ubitux> nope
[16:16] <ubitux> i'm busy, sorry
[16:16] <average> ok, I'm on my own then
[16:16] <average> btw, that's not what I asked for
[16:16] <average> what I mean it is I want a visual representation of the equalizer injected into the video stream
[16:21] <average> is it possible to convert an audio file into an equalizer video ?
[16:23] <ubitux> i was kind of answering the fade thing
[16:24] <ubitux> for equalizer, something close is showspectrum/showwaves i suppose
[19:50] <zumba_addict> hey folks, what are the parameters to show which acodec are supported on my ffmpeg?
[19:50] <JEEB> if your ffmpeg is new enough, -codecs
[19:50] <JEEB> and then you can grep through that
[19:51] <JEEB> (I think at least)
[19:51] <JEEB> I don't think -codecs:a and -codecs:v work
[19:51] <zumba_addict> it's like few months old maybe 3-4
[19:51] <zumba_addict> yup, -codecs worked
[19:52] <zumba_addict> i was wondering why -acodec libfaac wasn't working
[19:52] <JEEB> you shouldn't be using faac to begin with nowadays tho
[19:52] <zumba_addict> what should i use?
[19:52] <zumba_addict> -codecs showed tons of lines
[19:52] <JEEB> if you have to use binaries that someone distributes
[19:52] <JEEB> then aac
[19:52] <JEEB> (the lavc aac encoder)
[19:53] <zumba_addict> so -acodec aac?
[19:53] <JEEB> if you can build yourself
[19:53] <JEEB> then fdk-aac
[19:53] <JEEB> (both faac and fdk-aac are under the nonfree flag which makes you unable to distribute the binary)
[19:53] <JEEB> (and fdk-aac is the better one of the two)
[19:53] <zumba_addict> k
[19:54] <JEEB> also you can switch to the -c way of setting a/v/s "codecs"
[19:54] <JEEB> -c:a aac
[19:54] <zumba_addict> looks like aac worked. I got this  - Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), fltp, 384 kb/s
[19:54] <zumba_addict> now, i'm checking why it was so quick
[19:54] <JEEB> ac3 is not aac although I bet that's the input :P
[19:54] <zumba_addict> something wrong here? ffmpeg -i 00028.MTS -ss 00:00:50 -t 00:00:16 -vcodec libx264 -acodec aac -ac 2 -preset slow -crf 22 snow1.mp4
[19:55] <zumba_addict> maybe -t is wrong?
[19:55] <JEEB> can't see anything specifically wrong, 16 seconds of content encoded from 50 seconds onward?
[19:55] <zumba_addict> yup
[19:55] <zumba_addict> it ran only for 1 second
[19:55] <JEEB> unless you have a slow cpu, it should be pretty fast
[19:56] <zumba_addict> it's working now
[19:57] <zumba_addict> i used libfdk_aac
[19:57] <zumba_addict> aac wasn't working
[19:57] <JEEB> it should be
[19:57] <JEEB> unless you specifically disabled the internal aac encoder when compiling the binary
[19:57] <zumba_addict> maybe, i couldn't remember anymore
[19:58] <zumba_addict> the mp4 file worked great :)
[19:58] <zumba_addict> now, I'm going to search my unix history to find out how I was able to slow down the video. I want it slow motion a little :)
[19:59] <zumba_addict> is this good, https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video
[19:59] <JEEB> yup, what I was thinking of
[20:00] <zumba_addict> cool
[20:00] <zumba_addict> i wish we can slow down a video starting at N frame or seconds
[20:00] <JEEB> oh you could, but the libavfilter scripting isn't exactly nice on eyes
[20:01] <zumba_addict> oh ok
[20:02] <zumba_addict> this didn't work. It freeze the video - ffmpeg -i snow1.mp4 -filter:v "setpts=-0.5*PTS" output.mp4
[20:02] <roerp> hello
[20:02] <zumba_addict> it worked when it was a positive value
[20:03] <zumba_addict> i'm trying 2.0*PTS based on doc
[20:04] <roerp> I get an error when trying to compile ffmpeg git with --enable-libvidstab
[20:06] <roerp> hope somebody can help me: I am on ubuntu 12.04, ffmpeg git form today,  the error is http://paste.ubuntu.com/6704827/
[20:53] <zumba_addict> how do I fade out last 60 frames?
[20:57] <zumba_addict> i got it working
[20:57] <zumba_addict> does ffmpeg keep the same settings if we dont' supply info?
[20:58] <llogan> zumba_addict: what?
[20:59] <zumba_addict> looks like it kept it
[20:59] <zumba_addict> meaning if I don't put param like -vcodec
[20:59] <zumba_addict> or even -r
[20:59] <zumba_addict> it kept my 59.96fps
[21:10] <Ove-fdhgaf> Hello everyone.
[21:10] <Ove-fdhgaf> I have to implement a program that would capture from a webcam, encode the frames using an encoder and write them into a file.
[21:10] <Ove-fdhgaf> Then, after closing that file, maybe some other time, I need to capture some more frames, encode them and append them into the same file, at the end.
[21:10] <Ove-fdhgaf> Capturing and encoding is the easy part. How can I use ffmpeg to append to a video file after it has been closed?
[21:11] <Ove-fdhgaf> The format of the file can be anything as long as it can be played with any player (WMP, VLC, MPC, etc)
[21:20] <klaxa> Ove-fdhgaf: see: https://trac.ffmpeg.org/wiki/How%20to%20concatenate%20%28join,%20merge%29%20media%20files
[21:24] <Ove-fdhgaf> klaxa: I have read that, and it merges two existing files into a third file. That means it demuxes the two source files and muxes both of them together into the destination file (2 demuxes, 2 muxes).
[21:24] <Ove-fdhgaf> I would like to append to a file, without creating an extra file (1 mux to create the original file, 1 mux to append to the file, 0 demuxes needed)
[21:25] <Ove-fdhgaf> (I want to use ffmpeg in my own C++ code, not the command-line version)
[21:31] <llogan> Ove-fdhgaf: start by looking in tools/examples
[21:31] <llogan> *docs/examples
[21:36] <zumba_addict> can we use ffmpeg to combine videos into single?
[21:36] <zumba_addict> i've been using mp4box
[21:36] <Ove-fdhgaf> llogan: The "muxing.c" example in doc/examples overwrites the output file, it does not append to it
[21:37] <zumba_addict> if so, ffmpeg -i 1st.mp4 -i 2nd.mp4 -i 3rd.mp4 new.mp4. Is this correct?
[21:40] <zumba_addict> that command didn't work
[21:45] <relaxed> zumba_addict: what are you trying to do?
[21:46] <zumba_addict> combining mp4 files
[21:46] <zumba_addict> they have similar encoding usig ffmpeg
[21:46] <relaxed> MP4Box -cat 1.mp4 -cat 2.mp4 -new combined.mp4
[21:46] <relaxed> MP4Box is part of gpac
[21:47] <zumba_addict> yes, I mentioned earlier that I was using MP4Box
[21:47] <zumba_addict> however, I can't install MP4box on my osx, it's giving me an error
[21:47] <relaxed> I'm too lazy to scroll up.
[21:47] <zumba_addict> it's good now. I ran this -> ffmpeg -i "concat:intermediate1.ts|intermediate2.ts|intermediate3.ts|intermediate4.ts" -c copy -bsf:a aac_adtstoasc new.mp4
[21:49] <zumba_addict> i played the whole video and no issues :D
[21:49] <relaxed> I love how 1st.mp4 2nd.mp4 magically turned into intermediate1.ts intermediate2.ts
[21:49] <zumba_addict> maybe I should add an audio because it's so quiet
[21:50] <Ove-fdhgaf> the "-i concat" command demuxes the original files and remuxes them into the destination file. Is there any way (maybe using the C interface of ffmpeg) to just append the new packets to the end of the first file and to eliminate the need to demux and remux?
[21:50] <zumba_addict> this one relaxed: ffmpeg -i 1st.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
[21:51] <relaxed> Why not use mp4box directly?
[21:51] <zumba_addict> i don't have MP4box on this mac os x. it's failing to instal
[21:51] <zumba_addict> i said that earlier :)
[21:52] <relaxed> ain't nobody got time to scroll up
[21:53] <zumba_addict> i just mentioned it like 10 lines above
[21:53] <zumba_addict> you don't need to scroll :)
[21:53] <zumba_addict> http://pastebin.com/LnPWqUww
[21:53] <zumba_addict> now, that's a new paste
[21:53] <relaxed> ain't nobody got time to resize their very small chat window
[21:53] <zumba_addict> lol, cmon, that's so obvious, hehehe
[21:53] <zumba_addict> it's ok
[21:53] <zumba_addict> I will try from source later
[21:54] <relaxed> oh yes, gpac is the most frustrating thing to compile I've ever encountered
[21:54] <zumba_addict> oh ok
[21:55] <zumba_addict> I'm going to read this later
[21:55] <zumba_addict> http://gpac.wp.mines-telecom.fr/2011/05/02/compiling-gpac-for-macos-x/
[21:56] <relaxed> you would think they'd have something simple, like: ./configure --i-only-want-mp4box
[21:56] <zumba_addict> yup,, that would be awesome
[21:57] <relaxed> but no, you have to --disable-* 90% of the defaults
[21:57] <zumba_addict> i can ftp the files to my linux box and run mp4box from there
[21:57] <zumba_addict> sometimes when files are big, I become lazy in uploading
[21:57] <zumba_addict> especially i'm on wifi
[21:57] <relaxed> ok, I just made up the 90%, but it's enought that the devs should be stabbed.
[21:58] <zumba_addict> i agree! :D
[21:58] <relaxed> in the face
[21:59] <relaxed> if only mkvmerge could handle mp4s
[22:01] <JEEB> implement concateration support in L-SMASH and enjoy a much better build system?
[22:02] <relaxed> sounds like a job for JEEB
[22:02] <JEEB> too bad my TODO list is already pretty long
[22:02] <relaxed> support in ffmpeg would be better.
[22:05] <beastd> How is MP4box doing the concatenation?
[22:09] <relaxed> JEEB: Do any *nix tools use L-SMASH? I've heard you talk about it before but through my use of gnu pinko commie tools I've never run across something with support.
[22:12] <JEEB> relaxed, x264 lately finally got support for it merged as the preferred alternative to GPAC
[22:12] <JEEB> don't know of too many projects using it because of the lack of name for the project, but I've already seen some people use it for proprietary stuff a year+ ago
[22:13] <JEEB> because the license is more permissive
[22:23] <relaxed> beastd: the source is readily available, but if it's anything like the build system...
[22:24] <beastd> relaxed: thanks. though i guessed that the source is available. just wanted to know how it compares to what ffmpeg can do ATM
[22:24] <beastd> and was to lazy to RTFS ;-)
[22:25] <relaxed> well, it's been a while but I didn't think ffmpeg could concat mp4s at all.
[22:25] <relaxed> So...I'd say it's much better :P
[22:25] <JEEB> yes, GPAC's code base isn't exactly nice either
[22:26] <JEEB> GPAC was the main reason why L-SMASH got started
[22:26] <JEEB> just that L-SMASH doesn't get French government assistance and university funding etc.
[22:26] <beastd> Why do you think ffmpeg cannot concat them? If the parts are kind of similar it should work with the concat demuxer like anything else? What am I missing?
[22:27] <JEEB> not sure if it fails right now and the exact reason, but mp4 is not a "simple" format, so you end up possibly needing some extra calculations to be done to get the timestamps right
[22:28] <JEEB> I really don't remember how much of a hack the concat demuxer was
[22:30] <vivid> hello, does anyone know how i can stream audio well in linux? my video is good at 720p, and audio is fine but adds latency throughout the broadcast.  obv im using pulse, but i cant figure out how to get around it since all my applications that i need to get sound from are sending it to pulse
[22:33] <beastd> JEEB: i think it covers ts recalculation, though i do not think it special cases mp4. if it does not work for concat mp4 i think opening a ticket would be a start.
[22:38] <relaxed> with the quick test I just ran, git-2013-12-21-a07d4bc did not concat my mp4s
[22:38] <relaxed> and I was using the same mp4, twice
[22:38] <beastd> relaxed: you tested with the concat demuxer?
[22:39] <relaxed> -i concat:blah.mp4\|blah.mp4 -map 0 -c copy out.mp4
[22:39] <beastd> relaxed: that is the concat protocol. (AFAICT that is expected to not work with mp4)
[22:40] <relaxed> this is my current beef with ffmpeg- too many kitchen sinks
[22:41] <relaxed> it's fucking confusing and I usee it quite a bit
[22:41] <beastd> relaxed: yeah. kind of agree. but at least most things are possible. some are not *sooo* intuitivve
[22:42] <relaxed> instead of fixing shit you (not you personally) add more complexity
[22:43] <beastd> relaxed: please calm down a bit (i am understanding you are not attacking me in particular)
[22:43] <beastd> to summerize concat situation is much better nowadays in ffmpeg than it was a year or so ago
[22:43] <relaxed> plural
[22:43] <beastd> BUT the nice user interface is missing  (and it might not be easy to add it)
[22:43] <relaxed> concats
[22:44] <relaxed> "Hey, -i concat:1.mp4\|2.mp4 doesn't work." "Oh! You have to use the other concat."
[22:45] <beastd> nice user interface to concat that is like users want it to be: put my damn files together as good as possible but do not bother me with any syntax details
[22:45] <beastd> *
[22:46] <beastd> and for sure i can understand that attitude
[22:46] <relaxed> so it's a filter now?
[22:46] <relaxed> yes, I see it is.
[22:46] <beastd> it is a protocol, a demuxer and a filter
[22:47] <beastd> usually you want to use the demuxer in most cases and the filter as a last resort (it requires full re-encoding)
[22:49] <beastd> the concat protocol is only useful for certain types of containers
[22:50] <beastd> relaxed: you should be able to find out about things here: http://www.ffmpeg.org/faq.html#How-can-I-concatenate-video-files_003f
[22:50] <beastd> i agree a nicer way to bring this to our end users would be cool
[22:50] <relaxed> Yeah, I wrote part of that.
[22:51] <beastd> relaxed: it was partly rewritten :P
[22:51] <beastd> i even fear as useful as concat demuxer is it can even be harmful at times (but it is long since i looked at its source, some things were improved IIRC)
[22:59] <relaxed> That flv makes me laugh now. I could rewrite that with no fifos and half the characters in a posix compliant sh script.
[22:59] <relaxed> flv concat example*
[23:01] <beastd> also i think one could just use as well use the concat filter instead. please tell me if i am missing somethine.
[23:01] Action: beastd gets sleepy
[23:02] <relaxed> No, I think you're right.
[23:03] <beastd> maybe that FAQ should be rewritten again for a start
[23:03] <beastd> ATM I don't feel like doing it though :(
[23:05] <relaxed> right, scratch the faq and move to the wiki
[23:06] <relaxed> sending git diffs to the mailing list for doc updates is for the birds
[23:07] <beastd> relaxed: not sure i understand. but moving FAQ in the wiki may be a good idea
[23:08] <relaxed> currently you have to send patches to the mailing list to update the faq
[23:09] <relaxed> which is probably why it's out of date
[23:09] Action: relaxed is sleepy too. Good night, beastd.
[23:09] <beastd> n8
[00:00] --- Tue Jan  7 2014