[Ffmpeg-devel-irc] ffmpeg.log.20130817

[burek]

[00:10] <tlhiv_laptop> hi ... i'm having trouble with A/V sync when recording from my webcam ... is there a way to capture "raw" video and audio into a file and process it after it is done capturing?
[00:19] <llogan> tlhiv_laptop: did you try "-c copy"?
[00:19] <tlhiv_laptop> no
[00:20] <tlhiv_laptop> instead of -vcodec libx264 -acodec libfaac
[00:20] <llogan> yes
[00:22] <tlhiv_laptop> llogan: thank you ... i'll try that
[02:00] <Lerg> Hello guys
[02:01] <Lerg> I am experiencing an error video4linux2 ioctl(VIDIOC_ENUMSTD): Invalid argument when trying to capture
[02:01] <Lerg> I use a raspberry pi computer with archlinux arm
[02:02] <Lerg> And a kinda hybrid linux kernel
[02:03] <Lerg> I have kernel 3.10.6-1 but with the whole driver/media directory taken from the latest 3.11 rc kernel
[02:04] <Lerg> My video device is easycap UTV007 (driver usbtv)
[02:04] <Lerg> I wonder were is that error comes from?
[02:05] <Lerg> Command just: ffmpeg -f v4l2 -i /dev/video0 out.avi
[02:13] <Lerg> My current ffmpeg build is from August 11, quite fresh...
[02:13] <Lerg> I just wonder if I need to recompile ffmpeg
[02:26] <Lerg> llogan: http://pastebin.com/XJNqENWD
[02:33] <Lerg> any ideas?
[02:43] <llogan> Lerg: no. you could try asking on ffmpeg-user mailing list.
[03:28] <Lerg> Hm. Is libav and avconf a totally diferent project?
[03:28] <Lerg> Because on my other machine x86_64 with 3.11-rc5 this devices works good
[03:28] <Lerg> with avconv
[03:32] <sacarasc> Read that, Lerg.
[05:33] <diegoviola> hi
[05:34] <diegoviola> is there a way to capture webcam from v4l2 and output to /dev/null or something
[05:35] <diegoviola> i'm trying ffmpeg -f video4linux2 -i /dev/video0 -y /dev/null
[05:35] <klaxa> ffmpeg -i /dev/video0 pipe: > /dev/null
[05:36] <diegoviola> oh
[05:36] <klaxa> and the -f part
[05:44] <diegoviola> i try that but i get: At least one output file must be specified
[05:45] <klaxa> diegoviola: pastebin your complete output with the command you executed
[05:47] <diegoviola> https://gist.github.com/diegoviola/6255154
[05:47] <diegoviola> sorry if i did something wrong
[05:48] <klaxa> you forgot the "pipe:"
[05:48] <klaxa> diegoviola: ‘
[05:49] <diegoviola> oh
[05:49] <diegoviola> https://gist.github.com/diegoviola/6255162
[05:50] <diegoviola> now i get that
[05:50] <klaxa> you will have to specify a container format
[05:50] <klaxa> try: ffmpeg -f video4linux2 -i /dev/video0 -f matroska pipe: > /dev/null
[05:51] <klaxa> that will mux your video stream into a matroska container
[05:51] <diegoviola> that works
[05:52] <diegoviola> but i was expecting i would get a window but the output would go to /dev/null :D
[05:52] <diegoviola> is that possible
[05:52] <klaxa> hm...
[05:52] <klaxa> dunno, lol, why not just play back the stream from /dev/video0?
[05:52] <klaxa> ffplay -f video4linux2 /dev/video0
[05:53] <diegoviola> that's what i wanted to do, thanks
[05:53] <diegoviola> sorry about that :D
[05:53] <klaxa> heh
[05:53] <klaxa> well you'll know it for the next time :)
[05:53] <diegoviola> right, thanks
[05:54] <diegoviola> :D
[05:54] Action: diegoviola blushes
[05:56] <diegoviola> sweet, it does fullscreen too [f]
[05:57] <diegoviola> thanks a lot
[08:22] <pchel> Hi guys
[08:22] <pchel> I have a question about ffmpeg (today git version).
[08:22] <pchel> I have Logitech c920 webcam which produce yuvj420p video stream.
[08:22] <pchel> I want to copy this stream into video container (don't decode/encode it).
[08:22] <pchel> I'm trying a command: /home/ps/work/ffmpeg/ffmpeg -f alsa -ac 2 -i plughw:CARD=C920,DEV=0 -acodec aac -vcodec h264 -f v4l2 -i
[08:22] <pchel> dev/video0 -q 0 -vcodec copy -y -strict -2 out.mpeg
[08:22] <pchel> But I get just sound, the video is absent in the container.
[08:22] <pchel> Is it possible just copy video stream without decode/encode?
[08:22] <pchel> Repeat the command: ffmpeg -f alsa -ac 2 -i plughw:CARD=C920,DEV=0 -acodec aac -vcodec h264 -f v4l2 -i /dev/video0 -q 0 -vcodec copy -y -strict -2 out.mpeg
[08:57] <sxpert> good morning
[08:57] <sxpert> I have this broken flv file that I need to extract usable stuff from
[08:57] <sxpert> I know the exact format it's supposed to be
[08:57] <sxpert> how can I tell it to ffmpeg so that it only looks for that ?
[09:06] <sxpert> format I want to impose should be identical to http://pastebin.com/wYDpkvQh
[12:42] <asherawelan> Morning& I'm attempting to create a feed for a ffserver stream and I'm receiving this error. What am I missing?
[12:42] <asherawelan> Could not find codec parameters for stream 0 (Video: rawvideo (I420 / 0x30323449), yuv420p, -4 kb/s): unspecified size
[12:42] <asherawelan> Consider increasing the value for the 'analyzeduration' and 'probesize' options
[12:42] <asherawelan> The error is "Picture size 0x0 is invalid"
[14:12] <emzi> Why I get this error: Unknown input format: 'concat' after running the below command:
[14:12] <emzi> ffmpeg -f concat -i mylist.txt -c copy output
[14:14] <emzi> ffmpeg -version: ffmpeg version 0.10.7-6
[14:16] <JEEB> I wouldn't be surprised if that version just didn't have that format/demuxer
[14:30] <emzi> Isn't it the latest version?
[14:30] <JEEB> no
[14:31] <JEEB> or well, it could be within the 0.10.* branch
[14:31] <JEEB> but basically release branches are made at some point and they will only get bug fix backports from master after that
[14:31] <JEEB> no new features
[14:33] <emzi> JEEB: You mean the below repository is an old one while it shows 2013-01-16 for its updating time:
[14:33] <emzi> https://launchpad.net/~jon-severinsson/+archive/ffmpeg
[14:34] <JEEB> did you not understand what I just said about release branch versions :P
[14:35] <JEEB> the guy started building 0.10.x
[14:35] <JEEB> and there it is probably the newest, but
[14:35] <JEEB> you will not get any new features that were put in after 0.10.x
[14:35] <JEEB> the release was made, a branch created :P
[14:35] <JEEB> only bug fixes go in after that
[14:36] <JEEB> http://git.videolan.org/?p=ffmpeg.git;a=commit;h=7e16636995fd6710164f7622cd77abc94c27a064
[14:36] <JEEB> 0.10 release and branch was created in march 2012
[14:36] <emzi> ok
[14:36] <JEEB> (you can look here for the tags: http://git.videolan.org/?p=ffmpeg.git;a=tags )
[14:36] <JEEB> always when you are using a release
[14:37] <JEEB> you should check when that release branch was originally started
[14:37] <JEEB> :P
[15:35] <asherawelan> Can i set up ffserver to be connected to by a rtmp client?
[15:40] <shevy> is there a way to tell ffmpeg "if you ask me something, always assume that I answered yes"?
[15:40] <shevy> reason I would like this is because I use some batch-conversions, and it asks me before overwriting, and I always have to manually enter "y" then
[15:44] <DonGnom> shevy: iirc -y
[15:44] <DonGnom> (means just add -y as command line option)
[15:45] <shevy> ok cool a moment, lemme test
[15:48] <shevy> I think that works, thanks DonGnom, there was no yes/no query this time when using that command:
[15:48] <shevy>   ffmpeg -y -i "pfZ38WrbxYA.mp4" -acodec libmp3lame -ab 128k /Depot/j/pfZ38WrbxYA.mp3
[15:49] <DonGnom> shevy: np
[15:54] <sxpert> DonGnom: you seem to know stuff ;) how would I tell ffmpeg to look for a specific format in a broken file ?
[15:55] <sxpert> (idea being to fix said file)
[15:55] <DonGnom> sxpert: dunno (in fact im a ffmpeg noob i just knew that with -y because of my own batch conversions :)
[15:55] <sxpert> ah
[15:55] <sxpert> dang
[15:55] <sxpert> ;)
[15:56] <DonGnom> sxpert: but there are much xperts here if you just kindly ask the public someone will answer you the guys/girls here are usually very helpfull.
[15:57] <JEEB> sxpert, the most you can do is set the format with -f
[15:57] <JEEB> before -i
[15:58] <JEEB> if that fails then you ain't gonna get no magic :P
[15:58] <sxpert> JEEB: I would like to tell it to look for the actual format,
[15:58] <sxpert> specifying the contnents of the proper header to look for
[15:58] <JEEB> no such feature, you can just hope it probes the file correctly and/or have the probesize be made bigger
[15:59] <JEEB> if ffmpeg -i welp.file or ffprobe welp.file with a bigger probesize or whatever don't do it
[15:59] <sxpert> tried that. finds something that makes no sens
[15:59] <JEEB> well, if you then don't know the format you're SOL without some manual handiwork :P
[15:59] <sxpert> damn
[16:00] <sxpert> there should be a "skip until you actually find blah"
[17:56] <CentRookie> hi all
[17:57] <CentRookie> has anyone of you tried hardcoding .sub files into video?
[17:57] <CentRookie> it seems my ffmpeg doesnt support .sub files, do i have to compile it extra in order to enable .sub support?
[17:59] <klaxa> what kind of format is .sub? i mean sure it's a subtitle, but... does it have a more elaborate name?
[18:00] <CentRookie> im not sure how to check, it is 6mb big for 1 hour video length and comes with an idx file
[18:00] <klaxa> run ffmpeg -codecs | grep D.S to find all decodable subtitles
[18:00] <CentRookie> ass and srt are supported for now on my ffmpeg
[18:01] <klaxa> sounds like dvd stuff from little google research
[18:01] <CentRookie> yeah, probably
[18:01] <CentRookie> i was astonished why a sub file can be 6mb big
[18:02] <klaxa> yeah that's hard to achieve, even in .ass
[18:02] <CentRookie> http://pastebin.com/Ejk9nVxJ
[18:02] <klaxa> you could see if aegisub or some other subtitle editor can open it and then save it in a more sophisticated format
[18:02] <CentRookie> oh
[18:03] <CentRookie> yeah that would be possible, but im not awware of a batch function in aegisub
[18:03] <CentRookie> cuz its like 50 files
[18:03] <klaxa> ah you have a bunch of that?
[18:03] <klaxa> hmm...
[18:03] <klaxa> can you upload one .sub .idx pair?
[18:03] <CentRookie> yeah
[18:05] <CentRookie> hm where to upload to...
[18:05] <CentRookie> used to be so easy and hassle free to upload files
[18:05] <CentRookie> back in megaupload days
[18:06] <klaxa> mediafire
[18:08] <CentRookie> oh i see now
[18:09] <CentRookie> those are images
[18:09] <CentRookie> and dual language
[18:10] <CentRookie> alright, have to do it by hand then
[18:10] <CentRookie> im running ocr now
[18:10] <shevy> laters everyone
[18:12] <klaxa> ahah now i remember
[18:12] <klaxa> yeah
[18:12] <klaxa> that's the crap with dvdsubs
[18:12] <CentRookie> truly ...
[18:12] <CentRookie> its what happens when there are no real utf8 standards
[18:13] <CentRookie> and the subs are horrible too
[18:15] <klaxa> there is a way to hardsub this though...
[18:17] <klaxa> CentRookie, what you *could* do is decode the stream with rendering the subtitles, then encode the raw stream produced
[18:17] <klaxa> you wouldn't need to save the stream inbetween, just...
[18:17] <klaxa> it would seperate the decoding and encoding a bit more on the command line, because i don't know how ffmpeg handles dvd subs
[18:18] <klaxa> since i don't know better, i would play back the video with mplayer/mplayer2/mpv and grab the video in yuv4mpeg with ffmpeg over a named pipe and then encode with ffmpeg
[18:23] <relaxed> mplayer -nosound -benchmark -vo yuv4mpeg:file=>(ffmpeg -f yuv4mpegpipe -i - output.h264 2>ffmpeg.log) anime.mkv
[18:24] <CentRookie> hm
[18:24] <relaxed> add -ass or whatever you need to the mplayer command.
[18:25] <CentRookie> that's certainly new to me
[18:25] <CentRookie> so i would have to install mplayer and go with relaxed code line
[18:26] <klaxa> relaxed, those are dvd subs, so libass wouldn't do anything really, would it?
[18:26] <CentRookie> i tried analyzing with ffmpeg 2.0 and it rejected .sub files
[18:26] <klaxa> ah the whatever would be --sub=subtitle_file.sub
[18:26] <CentRookie> libass doesnt work obviously
[18:27] <CentRookie> ah right
[18:27] <CentRookie> it has its own command
[18:27] <klaxa> ffmpeg recognizes it as dvdsub for me though
[18:28] <CentRookie> yeah, works
[18:29] <CentRookie> it rejected when i tried to convert it to ass
[18:30] <CentRookie>  ffmpeg -i "black01.sub" -map 0:1 black01.ass  gives out [ssa @ 0x14abb00] Only SUBTITLE_ASS type supported.
[18:43] <relaxed> sorry, just woke up and glanced at the issue.
[18:43] Action: relaxed funnels coffee
[18:46] <CentRookie> relaxed, thank you for your "glance" mm, I havent worked with mplayer before and havent used raw stream output as ffmpeg input, do you think you could write a working example for me so that I can use it without much modification for my own file? I have a input.mpg video file with input.idx and input.sub file, the input.sub file is a subtitle file with 2 language streams, 0:1 is English, this is the stream I would like to use and my overal
[18:54] <relaxed> If the video and subs have the same name mplayer will automatically load them.
[18:55] <relaxed> do the correct subs come up when you play it with mplayer?
[19:00] <CentRookie> its a remote server
[19:00] <relaxed> CentRookie: the thing with dvds is the framerate may change, so this method could destroy audio/video sync.
[19:00] <CentRookie> so i cant verify until the whole video is complete i guess
[19:00] <CentRookie> yeah, im aware of that
[19:00] <CentRookie> i think ffmpeg rounds the fpsrate, right
[19:01] <CentRookie> when i checked the video input file it only said 23.8 fps, while standard should be 23.76 or something
[19:01] <relaxed> but mplayer won't
[19:01] <relaxed> and in this method it's feeding ffmpeg
[19:01] <CentRookie> well yeah, it is strange
[19:02] <CentRookie> i tried to fast convert mkv to mp4 with audio and video stream copy
[19:02] <CentRookie> but no matter what i did, it always ended with audio being 0,8 seconds too early
[19:03] <CentRookie> while mkv would play in sync
[19:03] <relaxed> I don't know the reason, but matroska is a more flexible container.
[19:04] <CentRookie> i then tried seperating video and audio input by loading it via mapping, same video twice
[19:05] <CentRookie> ffmpeg -y -i input.mkv -itsoffset 00:00:00.700 -i input.mkv -map 0:v -map 1:a -vcodec copy -acodec copy output.mp4
[19:05] <CentRookie> looked like this
[19:06] <CentRookie> but no matter how high i changed offset, the video of the output file had a 0,7 second delay
[19:07] <relaxed> does it happen at the beginning?
[19:07] <CentRookie> yes, stays during the whole movie
[19:07] <CentRookie> just wanted to know if i used the parameters correctly
[19:08] <CentRookie> this means that audio would be delayed by 0,7 seconds, or?
[19:08] <relaxed> maybe --> man ffmpeg|less +/^'       -async'
[19:09] <CentRookie> ^^
[19:09] <CentRookie> enough of manuals!
[19:09] <CentRookie> i read through 100 pages already
[19:11] <relaxed> reading is fundamental
[19:12] <CentRookie> well time management is even more important!
[19:13] <relaxed> -itsoffset might require encoding.
[19:13] <relaxed> instead of stream copying
[19:13] <CentRookie> hm
[19:13] <relaxed> test it with -t $time after the 2nd input.
[19:13] <CentRookie> ok
[19:14] <relaxed> tsmuxer might be able to do it.
[19:15] <relaxed> why are you inflicting this kind of pain on yourself? work?
[19:16] <hendry> hi there, I have a 462M voice recording in flac and I want it as small as possible. Can any of you suggest another format?
[19:16] <CentRookie> hendry, acc or vorbis
[19:17] <relaxed> or mp3
[19:17] <CentRookie> hm, so there is a linux version for tsmuxer
[19:17] <relaxed> yes
[19:17] <hendry> CentRookie: isn't it "aac"?
[19:18] <relaxed> I use it to create avchd dvds
[19:18] <CentRookie> yes, aac sorry
[19:18] <CentRookie> you can also try aac+
[19:20] <CentRookie> you need to compile ffmpeg with support for those libs though, hendry, if you are on linux that is
[19:21] <relaxed> hendry: ffmpeg -v 0 -codecs|grep "aac "
[19:22] <relaxed> what's the output?
[19:24] <hendry> relaxed:  DEA.L. aac                  AAC (Advanced Audio Coding)
[19:25] <relaxed> do you need this in a specific format?
[19:26] <hendry> relaxed: just as small as possible really
[19:26] <hendry> trying a conversion now http://ix.io/7m4
[19:27] <hendry> the MP3 is 116M and my upload channel sucks
[19:27] <hendry> should I be worried about 96 kb/s -> 128 kb/s I wonder
[19:28] <hendry> crap the aac is 158M. bigger!
[19:28] <CentRookie> lol
[19:28] <CentRookie> for speech you can probably go with 64 kb/s
[19:28] <relaxed> I thought you said this was a flac?
[19:29] <relaxed> use the flac as your input.
[19:29] <hendry> relaxed: i've exported it from Audacity again as a smaller mp3 now
[19:30] <relaxed> ffmpeg -i input.flac -c:a libvorbis -b:a 64k output.ogg
[19:31] <CentRookie> so few players support ogg, a pity
[19:35] <hendry> 76M output.ogg is best thanks
[19:36] <hendry> what about speex? it's a voice recording from a meetup?
[19:36] <CentRookie> bad support
[19:37] <relaxed> hendry: same size in mp3 --> ffmpeg -i input.flac -c:a libmp3lame -b:a 64k output.mp3
[19:37] <CentRookie> well ogg has slightly better quality
[19:38] <relaxed> true
[19:38] <CentRookie> alrighty, i tried moving itsoffset to other places
[19:38] <CentRookie> didnt have the effect at all
[19:38] <CentRookie> all the web tutorials either got it wrong
[19:38] <relaxed> did you encode?
[19:38] <CentRookie> well it would defeat the purpose
[19:38] <CentRookie> the goal was not to re-encode
[19:39] <relaxed> I think it's a requirement
[19:40] <hendry> oh yes, output.mp3 is just as small as the OGG really
[19:41] <CentRookie> ^^
[19:41] <CentRookie> according to some tut it should be like ffmpeg -i input.flv -itsoffset 00:00:03.0 -i input.flv -vcodec copy -acodec copy -map 0:1 -map 1:0 output_shift3s.flv
[19:42] <CentRookie> could try moe the vcodec parameters before the mapping
[19:42] <CentRookie> but doubt it will change anything
[19:47] <CentRookie> i think it is a version thingy
[19:48] <CentRookie> ffmpeg 2 might have something in it, that auto synchronizes audio and video stream and trims it to fit
[19:48] <CentRookie> just ignoring every offsetting parameter
[19:48] <CentRookie> it is similiar to its resolution
[19:49] <CentRookie> if i set output resolution to a res with an aspect of 16:9 and width 480 and height 760 or soemthing, and the input file has the aspect 4:3 it changes only width to 480 and keeps height according to aspect ratio
[19:49] <CentRookie> automatically
[20:14] <xlinkz0> Note that the timestamps may be further modified by the muxer, after this. For example, in the case that the format option avoid_negative_ts is enabled.
[20:14] <xlinkz0> how do i enable avoid_negative_ts ?
[21:18] <xlinkz0> is it possible to tell the concat demuxer to check if the last frame and the first frame of two consecutive files is the same and not copy it twice?
[00:00] --- Sun Aug 18 2013