[Ffmpeg-devel-irc] ffmpeg.log.20130410

burek burek021 at gmail.com
Thu Apr 11 02:05:01 CEST 2013


[00:31] <elkng> if I want to extract subtitles from mkv, should I use some option --enable- when compiling ffmpeg to add that ability ?
[00:32] <elkng> something like --enable-libass or other ?
[00:33] <elkng> will option --enable-gpl restrict of using additional libraries or allow to use them ?
[00:34] <klaxa> it will allow more libraries
[00:34] <elkng> it will allow to use gpl or not-gpl libraries ?
[00:34] <klaxa> it will allow both afaik
[00:35] <klaxa> default build is lgpl only so you can use ffmpeg in a commercial product
[00:35] <elkng> so its like --disable-gpl-restrictions ?
[00:36] <elkng> because --enable-gpl sounds like: "compile code with gpl license enabled so no non-gpl code will be compilled"
[00:36] <elkng> s/will be compilled/will not be compilled
[00:36] <relaxed> no, it means enable things that are only gpl
[00:37] <elkng> its like: "compile, but with gpl license taking into account"
[00:37] <elkng> thats why its frustrating
[00:37] <elkng> it would sound more clear if it was --enable-gpl-code
[00:37] <relaxed> as long as you distribute the binary it makes no difference
[00:37] <relaxed> you don't*
[00:38] <relaxed> and this in not #explain_the_difference_between_gpl_and_lgpl
[00:38] <relaxed> so go read up until you understand
[00:41] <elkng> what was that ?
[00:43] <elkng> I've heard some squeaky voice
[00:45] <llogan> elkng: you'll want --enable-libass if you're converting to ASS or if you want to use the subtitles or ass filters.
[00:46] <elkng> is opencv support currently broken ?
[00:46] <llogan> ...or at least if you're planning on using the filters
[00:46] <elkng> as it was in 0.11.1
[00:47] <llogan> is there an open bug ticket?
[03:47] <sinusss> hi does anyone have a Gingerbread device? Need to test a video :P
[03:48] <sinusss> *android
[03:55] <bourbon> I've got one in front of me
[03:55] <bourbon> that said
[03:56] <bourbon> do you have a way for me to ignore the input file's SAR/DAR?
[04:05] <relaxed> bourbon: why would you ignore it?
[04:05] <relaxed> do you want to change the output's dar/sar?
[04:06] <elkng> I have video file with subtitles: http://sprunge.us/BCPU and trying to extract subtitles from it I use command: "ffmpeg -i 1.mkv -map 0:4 -scodec copy out.ass" and that is the output: http://sprunge.us/ELia
[04:06] <bourbon> nope, I want to pretend that the input's SAR/DAR is valid
[04:06] <bourbon> lol... ass
[04:08] <elkng> or what is the right way to extract subtitles using ffmpeg ? should they be in ass format inside mkv or it can extract any subtitles ?
[04:08] <relaxed> elkng: "Stream #0:4(eng): Subtitle: dvd_subtitle" is not ass subs
[04:08] <elkng> in place of "dvd_subtitle" there should be "ass" word ?
[04:08] <relaxed> dvd subs are images, where as ass subs is a text file
[04:09] <elkng> other subtitles are incompatible with ffmpeg ?
[04:09] <relaxed> I believe you can copy dvd subs but not demux them.
[04:09] <bourbon> the issue I'm running into is that same one, man
[04:09] <rager> damn SAR/DAR are negative on the file
[04:10] <rager> it just seems like with options for everything else
[04:10] <rager> there should be options for explicitly declaring the DAR and SAR that ffmpeg will use
[04:10] <rager> and dealing with the consequences of such with filters
[04:10] <elkng> what if there is string "Stream #0:3(eng): Subtitle: subrip (default)" can they be extracted ?
[04:12] <relaxed> elkng: use mkvextract
[04:12] <relaxed> it can extract anything from the matroska container.
[04:14] <elkng> again that is the file: http://sprunge.us/bLaj     I use that command: "ffmpeg -i 2.mkv -map 0:3 -scodec copy out.ass" and that is the output: http://sprunge.us/FaWf
[04:14] <relaxed> rager: I'm guessing negative sar/dar vaules indicate a broken, or non-standard, video.
[04:15] <rager> oh
[04:15] <rager> it's totally non-standard
[04:15] <rager> but it manages to play in pretty much every player, as you saw a while back
[04:15] <rager> just...
[04:15] <rager> quicktime flips it upside down (the desired orientation)
[04:15] <relaxed> well, you can't expect ffmpeg to handle broken video correctly.
[04:15] <rager> and ffplay/vlc/whatever plays it "correct"
[04:15] <elkng> relaxed: is mkvextract goes inside mkvtoolnix ?
[04:15] <rager> true
[04:15] <rager> bleh... was just hoping there was a way around this
[04:15] <relaxed> elkng: yes
[04:15] <rager> I guess I could just make the iOS guy's life more fun
[04:16] <relaxed> pay him to not be retarded
[04:17] <rager> I hope he's not being paid hourly
[04:17] <rager> for being a tard
[04:17] <rager> the other issue I've got is in building ffmpeg for android :\
[04:18] <rager> the end of the output from "make"
[04:18] <rager> http://hastebin.com/haranedagu.rb
[04:18] <rager> and my options for building: http://hastebin.com/dusosebita.rb
[04:18] <rager> and the options for building x264
[04:18] <rager> http://hastebin.com/nubodedula.rb
[04:20] Action: rager shrugs
[04:20] <rager> I'll deal with it later
[04:20] <rager> it's the end of the day
[04:20] <rager> I need to go home
[04:22] <elkng> that is info from video file: http://sprunge.us/dXac does anyone know what does those strings: "Stream #0:5: Attachment: unknown_codec" means ? is that video,audio,subtitles or is it some useful data at all or not ?
[04:24] <elkng> that is a full output of ffprobe for that file: http://sprunge.us/UPbS what are those attachments ?
[04:33] <relaxed> elkng: mkvinfo, included with mkvtoolnix should be able to tell you.
[05:21] <schtinky> hey folks, got an intermittent bug/issue I'm dealing with. I'm currently doing "gnutv | ffmpeg " to capture video from a digital tuner card on a regular schedule...
[05:22] <schtinky> ... Most of the time, the command works just fine. But occasionally, it just hangs. No output is produced. gnutv and ffmpeg appear to be running according to "ps" but nothing is actually getting recorded
[05:23] <schtinky> would anyone have any insight into what might be causing this? (I'd say it "fails" 10% of the time on a set schedule.)
[05:25] <schtinky> the only thing /var/log/messages says at the time of the last failure is  xc5000 (my tuner card): "waiting for firmware to upload" "firmware uploading" and "firmware upload complete"
[05:25] <schtinky> I don't have any reason to suspect that behavior is any different than when the "gnutv | ffmpeg" command succeeds as expected
[05:26] <relaxed> I doubt this is an ffmpeg problem.
[05:26] <schtinky> yeah I was just thinking that
[05:26] <schtinky> probably need to ask #v4l2
[05:26] <schtinky> well #v4l anyway
[05:27] <relaxed> ffmpeg can caputure from v4ls devices. why not use it?
[05:33] <schtinky> I've tried to figure that out with no success, relaxed
[05:34] <schtinky> it seems that "ffmpeg -f v4l2 -i /dev/video0" only works on analog devices
[05:34] <schtinky> when I try it on /dev/dvb/adapter0/frontend0 or dvr0, I get operation not allowed or something
[05:35] <schtinky> I have tried to get an answer to this both on the wider internet and on this channel, but nothing yet
[05:35] <relaxed> schtinky: did you look here: https://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20capture%20a%20webcam%20input
[05:36] <schtinky> that's analog
[05:36] <relaxed> maybe you need to use `v4l2-ctl` to set it up?
[09:06] <Vardan> hi all
[09:07] <Vardan> people how can I get ffmpeg version from code?
[09:33] <Vardan> people I got this error "framerate not set" when trying to open encoder (CODEC_ID_MJPEG)
[10:14] <phuzE> Hey guys, does anyone have experience encoding screencapture on windows? I'm currently stuck on how to properly encode an HBITMAP into my video (my output is just a blank gray/white screen right now)
[10:26] <bogdanp> can anyone think of a reason why doing http://pastebin.com/raw.php?i=qzH0JaSu would result in http://i.imgur.com/2EmLbPj.png
[10:27] <bogdanp> I'm trying to convert RGB32 frames received from a camera to h264 video
[10:27] <bogdanp> but this has me stumped
[10:47] <lentferj> I would like to 1:1 map the metadata of all audio streams in a DVB video recording when converting with ffmpeg. But I can't seem to get this work (with current ffmpeg from git).
[10:48] <lentferj> http://pastie.org/7407658
[10:49] <lentferj> I tried with -map_metadata:s:a 0:s:a but that seems to copy the metadata from the 1st audio stream onto all audio streams
[10:50] <lentferj> when I map all streams one by one, it works (2nd part of the pastie), but this is not "generic" (or easy :) ), since I want to use it in a generic conversion script, where the input can have varying numbers of audio streams
[10:50] <lentferj> any idea?
[11:11] <lentferj> oh boy... that was too easy.... -map_metadata 0 ...
[13:11] <Vardan> people how to get video stream duration in seconds using C++
[13:50] <megaTherion> Vardan: did you check docs on avformat_open_input?
[13:50] <megaTherion> Vardan: beside's there is an seperate channel for this: #ffmpeg-devel
[14:25] <bogdanp> can anyone think of a reason why doing http://pastebin.com/raw.php?i=qzH0JaSu would result in http://i.imgur.com/2EmLbPj.png ? I'm trying to convert RGB32 frames received from a camera to h264 video but this has me stumped.
[14:35] <elkng> since when it became possible to extract subtitles from video ?  since 1.2 version ?
[14:45] <zap0> bogdanp, thats YUV colours
[14:45] <bogdanp> zap0, what is?
[14:45] <zap0> the picture
[14:46] <bogdanp> zap0, yes but shouldn't sws_scale convert the rgb pixel buffer to yuv? making the two frames look the same?
[14:48] <zap0> if you input r8g8b8 = 24bit,   and a convertion happened, the output would be  y8v2u2=12 bits.   so  did the output bytes be 1/2 the input bytes?
[14:48] <zap0> you might just be getting your U and V channels  backwards
[14:49] <zap0> a YUV signal in yv12 format is sometimes stored as Y,V,U ordering. instead of Y,U,V ordering.
[14:49] <zap0> how did you generate that frame?
[14:49] <zap0> can you switch U V ?
[14:57] <bogdanp> zap0, http://pastebin.com/raw.php?i=UMvFQPiW that's basically what I'm doing. I don't know how to switch U and V, is there some builtin function that can do it for me or do I have to do it manually? (if it's not already obvious, I'm a complete noob to video& stuf)
[14:57] <bogdanp> *stuff
[14:59] <zap0> have you tried doing basically the same with the command line app?
[15:06] <bogdanp> zap0, I haven't but I am going to do it now
[15:10] <bogdanp> zap0, it seems that capturing camera input on OS X isn't really possible from the command line
[15:10] <bogdanp> zap0, that or my google-fu is failing me hard
[15:16] <Snaggle> weee.  ffmpeg-next will have the ability to view/edit/transcode/* youtube videos just by passing it the url
[15:16] <retard> quvi?
[15:16] <Snaggle> yup
[15:17] <retard> that is super rad
[15:17] <Snaggle> pretty neat.  I just tried it, and even funner was passing it through libcaca
[21:58] <viric> Can ffmpeg use the vdpau deinterlacers?
[23:02] <tgreenwood> I was looking at https://ffmpeg.org/trac/ffmpeg/ticket/568 but checking the latest git it seems MAX_SLICES is still 16.
[23:08] <durandal_1707> tgreenwood: what would it need to change?
[23:09] <tgreenwood> It's just a 1 liner in h264.h
[23:09] <durandal_1707> you still get that bug or?
[23:09] <tgreenwood> I get visual artefacts if it's less than 64
[23:09] <durandal_1707> with what version?
[23:09] <tgreenwood> I am running 2 RTP endpoints
[23:09] <tgreenwood> I've been using gstreamer 1.0 I can get the git version if you like
[23:10] <tgreenwood> However I did check latest master for the value.
[23:10] <tgreenwood> I also work with some people who have increased the value in other RTP use cases.
[23:11] <durandal_1707> its very simple: if latest ffmpeg still have issue, reopen bug
[23:11] <tgreenwood> OK - will do thank you!
[23:12] <tgreenwood> I can post a patch as well if it would be helpful.
[23:12] <durandal_1707> tgreenwood: then send it to mailing list, but make sure it actually helps
[23:12] <durandal_1707> changing random line and not testing is ugly and bad
[23:13] <tgreenwood> Totally appreciate that I am testing with 2 H.264 RTP endpoints.
[23:14] <durandal_1707> if its so relevant than put it into log of patch you sent (eg. with git format-patch......)
[23:14] <durandal_1707> tgreenwood: if you want to discuss problem and solution for it you can ask on #ffmpeg-devel i guess
[23:17] <tgreenwood> Thanks - I may do that
[23:25] <shambala> Hi, I am creating a video from stills.. stills have transparent canvas, but when the video gets made, it has black fill, don't know why.. here is the command I am using
[23:25] <shambala> ffmpeg -y -f image2 -r 7 -i /Users/shambala/tabrez/rgplyrx1/tmp/video_creator/zi_1365622727_699172_572887_%04d.png -vf scale=520:600 -crf 0 -preset ultrafast -b:v 25000k -minrate 25000k -maxrate 25000k -bufsize 5000k  -tune stillimage -pix_fmt yuv420p -r 30000/1001 /Users/shambala/tabrez/rgplyrx1/tmp/video_creator/manoj_test.mpg
[23:26] <shambala> any issue with the options?
[23:29] <shambala> durandl_1707, here you go: http://pastebin.com/UxtpK9Pe
[23:37] <durandal_1707> shambala: it looks liky you encode this to mpeg1video but use options for libx264 encoder
[23:37] <durandal_1707> exactly what is mentioned 3 times in output you pasted
[23:40] <shambala> I removed those options, so errors are gone, but the fill issue remains
[23:43] <shambala> durandal_1701 I am loading pic and video in google drive, so you can see
[23:43] <shambala> sorry, durandal_1707
[23:48] <shambala> https://docs.google.com/file/d/0B6Pi2zJeMhv7UTQza1EyVzlrMjg/edit?usp=sharing
[23:48] <shambala> that's the pic
[23:49] <shambala> https://docs.google.com/file/d/0B6Pi2zJeMhv7RXY1N2dHR2xFMXM/edit?usp=sharing
[23:49] <shambala> that's the video& ffmpeg is adding a black fill
[23:49] <shambala> anyway to make it transparent
[23:49] <shambala> ?
[23:57] <llogan> shambala: you can't. mpeg1video doesn't support an alpha channel
[23:58] <llogan> what are you tryng to do? why do you need the transparency preserved?
[23:59] <saste> shambala, are you implementing a virtual cemetery?
[23:59] <llogan> i'm guessing it's a family history project
[00:00] --- Thu Apr 11 2013


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