[Ffmpeg-devel-irc] ffmpeg.log.20120306

burek burek021 at gmail.com
Wed Mar 7 02:05:01 CET 2012


[00:02] <flaxo> cbsrobot: ffmpeg -i video_pal.mpg -i subtitle.srt -sameq -scodec dvdsub -slang eng -map 0:0 -map 0:1 test.vob
[00:02] <cbsrobot> flaxo: try:
[00:03] <flaxo> video_pal.mpg has one video stream and one audio stream
[00:03] <cbsrobot> ffmpeg -i video_pal.mpg -i subtitle.srt -sameq -scodec dvdsub -slang eng -map 0:0 -map 0:1 -map 1:0 test.vob
[00:04] <flaxo> i did that before...
[00:04] <flaxo> sorry that part was missing above
[00:04] <flaxo> i tried the -newsubtitle parameter
[00:05] <flaxo> since i ran across it in some posts
[00:05] <flaxo> but with no avail
[00:06] <cbsrobot> flaxo: pastebin the whole command and output
[00:07] <cbsrobot> and add a "ffprobe -i test.vob" to the pastebin
[00:11] <flaxo> cbsrobot: ffprobe says there is a subtitle track but it will not show in video
[00:12] <cbsrobot> try to extract it to an srt again
[00:12] <flaxo> k
[00:12] <cbsrobot> ffmpeg -i test.vob -an -av -f srt test.srt
[00:12] <cbsrobot> or smthing in that regard
[00:12] <cbsrobot> ah - maybe it wont work
[00:13] <flaxo> srt is not supported
[00:13] <flaxo> i think on the output
[00:13] <flaxo> at least it is not listet in -codecs
[00:15] <ubitux> are you trying to convert srt to vobsub?
[00:15] <ubitux> vobsub are bitmap based
[00:15] <ubitux> srt is text only
[00:15] <ubitux> afaik it's not possible with ffmpeg, but i may be wrong
[00:15] <flaxo> ok
[00:16] <flaxo> manual made me believe it should work
[00:16] <ubitux> where?
[00:16] <Freakshow> so using h264 ffpresets is completely deprecated correct?
[00:17] <Freakshow> or will it 'still work' if you really want to be ugly about it
[00:18] <flaxo> ubitux: well the fact that srt is supported made me believe i could as well convert it
[00:18] <ubitux> you can convert it to .ass which is also text based
[00:18] <cbsrobot> Freakshow: for libx264 encoding preset end profile options are directly passed to x264
[00:18] <ubitux> but text ’ bitmap requires more complicated code
[00:18] <ubitux> and bitmap ’ text even more obviously
[00:19] <Freakshow> right ... with -x264opts
[00:19] <cbsrobot> Freakshow: that too
[00:20] <cbsrobot> Freakshow: you can pass any option to libx264 with -x264opts, but the ffmpeg options -preset and -profile will also get passed to libx264
[00:20] <Freakshow> oh sorry, misread your reply... right right
[00:20] <cbsrobot> directly
[00:20] <cbsrobot> np
[00:20] <flaxo> ubitux: ok thanks... i see the problem i just thougt it would work :)
[00:21] <ubitux> such feature is welcome though, so feel free to contribute
[00:21] <ubitux> :)
[00:21] <pasteeater> there are also some libx264 private options. there's a list of them in 'ffmpeg -h'
[00:21] <cbsrobot> flaxo: you can convert srt -> ass and then burn the subtitles into your video (hardsub)
[00:23] <darkstarbyte> What is the hardware accelerated mpeg2 encoder called?
[00:24] <Freakshow> hmm... -vpre preset        set the video options to the indicated preset
[00:24] <Freakshow> seems to be valid still
[00:24] <sacarasc> darkstarbyte: I don't think ffmpeg has one.
[00:25] <darkstarbyte> I thought it had one for cuda
[00:26] <darkstarbyte> I know mencoder has one.
[00:29] <chuck_> hi again, so first of all "-c copy" doesnt work so i used "-vcodec copy -acodec copy" instead. then i tried with -ss on both sides of "-i" and it still didn't worked. so i guess the only solution i have left is to reinstall ffmpeg along cbsrobot 's advice
[00:30] <santoshfamily> convert .mp4 to .avi  problem !
[00:30] <sacarasc> darkstarbyte: No, mencoder doesn't.
[00:30] <darkstarbyte> oh
[00:31] <flaxo> cbsrobot: thanks but i am looking for a way to actually get working dvd-subtitles from srt
[00:31] <sacarasc> MPlayer can decode using VDPAU and (with a patch) VAAPI, but AFAIK, it can't get the data back after it's been decoded by the video card.
[00:58] <pasteeater> Freakshow: it is still valid for the remaining text file based presets such as libx264-ipod640
[00:59] <pasteeater> chuck_: "didn't work" is a very common error here. use a pastebin site to show your ffmpeg command and the complete console output.
[00:59] <Freakshow> thanks pasteeater... I presume custom based presets will work as well if that's the case
[00:59] <Freakshow> obviously within reason
[00:59] <pasteeater> yeah, probably
[01:00] <Freakshow> I know it's not optimal but I can only deprecate functionality on my end so fast. :)
[01:00] <Freakshow> s/deprecate/migrate
[01:36] <aphid> I'm converting some footage someone produced in final cut, audio is "Stream #0:1(und): Audio: pcm_s24le (lpcm / 0x6D63706C), 48000 Hz, 5.1(side), s32, 6912 kb/s".   having trouble getting into web formats b/c of the 5.1 it seems;  any easy workflows to make it stereo?  -ac 2 doesn't work.
[01:51] <chuck_> pasteeater, cbsrobot i've just finished installing correctly ffmpeg. i was wondering if i can now deleted the x264 and ffmpeg folder created in my home directory while process
[01:52] <pasteeater> you can if you want. or you can keep it if you ever decide to upgrade them
[01:52] <cbsrobot> chuck_: you can - its linux after all but i suggest you move it to a devel folder
[01:52] <cbsrobot> to save some space you can "make clean" in the folders
[01:52] <cbsrobot> *in both folders
[01:52] <pasteeater> see the "Updating FFmpeg and x264" seciton of the guide for instrucitons on updating
[01:53] <chuck_> cbsrobot : what is the use of a devel folder (quite new to linux as you may have guessed)
[01:53] <cbsrobot> chuck_: all your devel stuff goes in there ...
[01:54] <cbsrobot> well name it as you wish
[01:55] <chuck_> cbsrobot : i mean that i dont get the usefullness of such folder, has it something to do with pasteeater just pointed me too ?
[01:55] <cbsrobot> yes
[01:55] <burek> chuck_, if you do delete the folder with source code, then you won't be able to automatically "uninstall" ffmpeg
[01:55] <burek> you'll have to do it by hand
[01:55] <chuck_> burek : ok thanks that is a very good reason for keeping it
[01:56] <cbsrobot> and as a bonus you can hack on ffmpeg or x264's source code !
[01:56] <burek> the best option is to use git
[01:56] <burek> and from time to time
[01:56] <chuck_> cbsrobot that is also a good reason :)
[01:56] <pasteeater> you can uninstall ffmpeg and x264 if you remove the source directories.
[01:56] <burek> to just do: make uninstall; make clean; git pull; make; make install
[01:56] <pasteeater> ...because the guide uses checkinstall and integrates the packages into your package management system
[01:57] <pasteeater> so therefore you can simply: apt-get remove ffmpeg x264
[01:57] <pasteeater> if you want to remove them
[01:57] <aphid> nevermind, it looks like one of these files just didn't have audio :(
[01:57] <burek> aphid, did you try with -map
[01:57] <chuck_> pasteeater : oh ok i get it
[01:58] <chuck_> time for trying these commands again
[01:58] <aphid> burek, nope
[01:58] <burek> or even better: http://ffmpeg.org/ffmpeg.html#Remapping-examples
[01:59] <burek> aphid, that's the link for you :)
[01:59] <aphid> ty, sir!
[02:00] <pasteeater> chuck_: and congratulations on your first (i'm assuming) successful compilation
[02:00] <burek> aphid, it would also help if you could show your command line with output, so we can see where did you make a mistake
[02:02] <chuck_> IT WORKS !!!! THANKS cbsrobot and pasteeater
[02:06] <chuck_> hm, it's almost perfect but i'm not sure that even with placing -ss after the -i i get an accurate cut, according to the link pasteeater sent me at 23:49. how can i be sure ?
[02:13] <chuck_> nevermind i've figured out. i'm leaving. thanks again !!!
[05:35] <woden> Hello, what would be the command to strip the audio from a video file?
[07:06] <annodomini> Is there any convenient way to create a video file from a single image file (filling in all of the frames of the video) and an audio file?
[07:08] <annodomini> If I just try ffmpeg -i image.png -i audio.mp3, it only writes the first frame out and gives me an error because it can't read more frames.
[07:10] <annodomini> I can create a bunch of symlinks from img0001.png, img0002.png etc to the original image, and use ffmpeg -i img%04d.png, but creating the appropriate number of symlinks in a directory takes forever.
[07:12] <relaxed> annodomini: ffmpeg -i audio.mp3 -loop 0 -i image.png
[07:13] <relaxed> add -shortest in there too
[07:13] <annodomini> Invalid value '0' for option 'loop'
[07:14] <relaxed> er, -loop 1
[07:15] <annodomini> -loop_input seems to work, though.
[07:17] <annodomini> Thanks, -loop 0 or 1 didn't work, but pointed me in the direction of -loop_input which does.
[08:10] <trupheenix> i have a question: in a GOP is it always compulsory that an I frame is at the beginning?
[08:10] <trupheenix> or is this dependent on the video type?
[09:38] <CruX|> hello I want to convert .avi into mkv because my satellite receiver have problems with playing .avi files
[09:38] <CruX|> I'm getting this error :[mpeg4 @ 0x2cdde20] Invalid and inefficient vfw-avi packed B frames detected, [mp3 @ 0x2cdea20] Header missing
[09:39] <CruX|> can be this file converted ?
[11:07] <TACPILOT> any one have an FOSS tool suggestion for removing motion blur post producion ??
[11:15] <Mavrik> "blur"?
[11:17] <TACPILOT> object moving causing blur when recording video
[11:18] <Tjoppen> lower the exposure time?
[11:18] <pom> What exaclty is missing when "ERROR: dirac not found" displays as ./configure time?
[11:18] <Mavrik> libdirac?
[11:19] <pom> Hmm, I've got this package "dirac-libs.x86_64" installed at least.
[11:19] <pom> And still showing.
[11:20] <Mavrik> you'll need development headers probably
[11:20] <pom> I've got this too "dirac-devel-1.0.2-6.fc16.x86_64"
[11:29] <pom> If ffmpeg says "Unknown encoder 'libfaac'", does that mean I _have_ to recompile and that it is not possible to add a .so?
[11:32] <Mavrik> yes.
[11:38] <knobo> how can I output a mpeg file to a v4lvloopback device?
[11:52] <pom> Um, can faad create Flash/webkit-compatible mp4 files?
[11:57] <Mavrik> faad is a decoder, so no :)
[11:57] <Mavrik> faac yes.
[11:58] <pom> Oh, okay. =)
[11:58] <pom> Do you know if anyone provides a ffmpeg package with faac support for Fedora or Debian?
[11:58] <pom> And is it possible to tell before installning?
[11:59] <Mavrik> no
[11:59] <Mavrik> because ffmpeg with libfaac isn't redistributable
[11:59] <pom> And #2, is ffmpeg -codecs reliable to show what is _really_ supported?
[11:59] <Mavrik> yes.
[12:00] <pom> Does this mean that redistributable versions of ffmpeg today cannot create Flash-compatible mp4 files?
[12:00] <pom> Or am I jumping to conclusions here?
[12:02] <Mavrik> you're jumping to conclusions :)
[12:02] <Mavrik> the redistributable packages usually include libvo_aacenc encoder for AAC
[12:02] <Mavrik> some people also use the built-in experimental AAC encoder (which is pretty bad though)
[12:03] <meta-coder> http://people.xiph.org/~xiphmont/demo/neil-young.html   There is no point to distributing music in 24-bit/192kHz format.
[12:03] <Mavrik> libvo_aacenc is approximately the same as libfaac quality-wise... it doesn't support more than 2 audio channels though
[13:03] <pom> Mavrik: Bfl, thanks for the info. Will dig deeper!
[13:06] <pom> Mavrik: How can I see if my package contains libvo_aacenc support? Should it be listed under that name in -codecs?
[13:06] <Mavrik> yes
[13:14] <pom> "    Stream #0.1: Audio: aac, 48000 Hz, stereo, s16, 64 kb/s" this means that it's using the internal aac codec, right?
[13:14] <pom> That is under "Output".
[13:25] <Pacefist> hi everybody
[13:25] <Pacefist> I got a problem while compiling ffmpeg using MSYS
[13:25] <Pacefist> on Windows 7
[13:27] <Pacefist> it's compiled well in MSYS environment, but I need compile it from cmd
[13:27] <Pacefist> something like this:
[13:28] <Pacefist> >msys.bat "./configure "
[13:31] <JEEB> that makes no sense
[13:31] <JEEB> if you want to run a configure script you run it via a shell script interpreter (the configure script is one)
[13:31] <JEEB> then you use make with it
[13:32] <Pacefist> any shell interpreter?
[13:32] <Pacefist> on Windows
[13:33] <Mavrik> Pacefist, run msys first
[13:33] <Mavrik> then compile as you would on linux from within the msys shell
[13:33] <Pacefist> I can't
[13:33] <JEEB> for some reason he wants to run the compilation from a command line, let me guess -- batch script automation?
[13:34] <JEEB> you can't?
[13:34] <Pacefist> yes, it's for "Jenkins" automated compilation
[13:34] <Pacefist> JEEB: yes, it's for "Jenkins" automated compilation
[13:34] <JEEB> -_-
[13:35] <JEEB> anyways, try using the sh binary that comes with msys
[13:35] <Pacefist> is it possible to compile it from cmd?
[13:35] <Pacefist> or from PowerShell
[13:35] <JEEB> damn if I know :P
[13:35] <JEEB> try running the configure with sh
[13:38] <Pacefist> I'm on it
[13:40] <Mavrik> Pacefist, as far as I know no
[13:40] <Mavrik> you need a working bash shell to run the build process
[13:41] <Pacefist> ls
[13:41] <Pacefist> sorry, not this windows
[13:41] <Pacefist> Yes, I suppose, I have found a solution
[13:46] <Pacefist> No
[13:46] <Pacefist> bash in cigwin can't compile that
[14:10] <Pacefist> can I compile ffmpeg using Visual Studio?
[14:10] <zap0> doubtful.
[14:11] <Mavrik> afaik msvc can't compile ffmpeg
[14:11] <perrth1> I also wonder why it can't?
[14:11] <Pacefist> What's shame
[14:11] <zap0> GCC-isms likely
[14:12] <perrth1> aren't VS2008 is more standard
[14:12] <CruX|> perrth1: don't think
[14:12] <perrth1> more conforming at least
[14:12] <zap0> who said FFMPEG was 'standard' ?
[14:12] <CruX|> gcc is for every architecture I know
[14:13] <CruX|> vc is only for win32/64
[14:13] <perrth1> no doubt about that :D
[14:14] <Pacefist> Well
[14:14] <Pacefist> I have one more question about ffmpeg
[14:14] <JEEB> perrth1, MSVC is primarily a C++ compiler, and doesn't support C99
[14:14] <JEEB> only the original C89
[14:15] <JEEB> ffmpeg might as well have some GCC'isms, but those should be less of a problem than general fact that ffmpeg uses C99 style
[14:15] <JEEB> if you want MS to support C99, there's only one place to go herp a derp about that :)
[14:15] <Pacefist> I have a transport stream (DVB stream), but I get it package by package (188 byte)
[14:16] <perrth1> ah I see, you're right what they're conforming is the C++0x not C
[14:16] <JEEB> well, they do have C compilation support as well
[14:16] <JEEB> but only for C89 features
[14:17] <JEEB> :)
[14:17] <Pacefist> Does the way to convert it to AVFormatContext exist?
[14:17] <Mavrik> also there are parts of ffmpeg written in ASM that require yasm to compile
[14:17] <JEEB> Mavrik, yes but that's less of a problem and yasm can nicely be integrated into MSVS
[14:17] <Mavrik> JEEB, good to know :)
[14:18] <CruX|> adm routenes are written only for x86 ?
[14:18] <Mavrik> Pacefist, yeah, you need to manually define ByteInputContext (or somesuch, don't remember exact name) which will do callbacks for you to pass it those bytes
[14:18] <CruX|> *asm
[14:18] <JEEB> CruX|, there's some gnu asm probably for ARM
[14:18] <Pacefist> Oh!
[14:18] <Pacefist> Mavrik: Thanks a lot
[14:18] <JEEB> maybe some PowerPC stuff?
[14:18] <JEEB> no idea
[14:18] <CruX|> i think about raspberry pi with ffmpeg :)
[14:18] <Mavrik> Pacefist, it's not really all that straightforward, check udp.c
[14:19] <Mavrik> CruX|, that'll be slower than a snail on weed
[14:19] <JEEB> Mavrik, fast enough for audio and stuff, considering that he will most likely handle video other way :)
[14:19] <CruX|> slower than old pentium ?
[14:20] <Mavrik> JEEB, yeah, but for video an old ARM without NEON @ 700 MHz isn't really useful
[14:20] <Mavrik> especially since the device has a pretty decent hardware encoder
[14:20] <Mavrik> (without APIs so far afaik)
[14:21] <JEEB> uhh, if it was without APIs how could their XMBC play it?
[14:21] <Mavrik> encoder.
[14:21] <JEEB> oh
[14:21] <JEEB> well, yeah -- but who'd want to encode stuff with that
[14:21] <Mavrik> they promised an SDK though
[14:21] <JEEB> anyways, it should be fast enough to do some audio decoding/parsing even on the ARM
[14:22] <JEEB> video decoding could be left for the hardware thingy
[14:25] <Pacefist> If: hi!
[19:57] <tjholowaychuk> hey. I'm compiling mp4s, the compression makes the videos look pretty bad though, are there flags to tweak the compression?
[20:02] <pasteeater> tjholowaychuk: use a pastebin site to show your ffmpeg command and the complete console output
[20:03] <pasteeater> i just compiled ffmpeg on a 400 MHz Pentium II.
[20:03] <pasteeater> ...now i'm goign to sign up for AOL and listen to N'SYNC.
[20:04] <tjholowaychuk> https://gist.github.com/1988242
[20:05] <tjholowaychuk> generating the initial video from images, grabbing the audio from an flv
[20:05] <tjholowaychuk> i could be doing something really wrong but the compression is pretty bad
[20:07] <pasteeater> ...and the complete console output. (so i can know what version of ffmpeg you're using and any useful info it pukes out)
[20:08] <tjholowaychuk> -qscale might be what im looking for
[20:08] <pasteeater> not necessarily. it depends on your ffmpeg version.
[20:08] <tjholowaychuk> one sec i'll dump stdout
[20:09] <pasteeater> mp4 used to default to 'mpeg4' encoder with crappy default settings (but usage of qscale is appropriate), and now it defaults to libx264 where the defaults are sane.
[20:09] <pasteeater> ...but you should never use qscale with libx264
[20:10] <tjholowaychuk> https://gist.github.com/1988242
[20:12] <pasteeater> it's defaulting to the encoder named mpeg4 and is using default bit rate of 200k which is terribly low for nearly all cases.
[20:13] <pasteeater> so you can either use qscale (try values from 2-5), or switch to another encoder, such as libx264. it depends on what output format you want.
[20:15] <tjholowaychuk> much better
[20:15] <tjholowaychuk> thanks!
[20:16] <pasteeater> you might be able to combine your first two commands. also see the -shortest option which will end the output depending on the shorter input
[20:17] <tjholowaychuk> ok cool i will check that out
[20:26] <funkster> using x11grab to do screen recording works great - my question is, if I wanted to launch a browser and record the brwser window, inside a program so i can use the desktop - what would I look into?
[20:31] <pasteeater> what do you mean by "inside a program"?
[20:40] <funkster> pasteeater: 1. so i can put it on different servers with different resolutions 2. so i can use the desktop, and not record what im doing to disrupt what i want to record in browser window
[20:41] <pasteeater> ok. i get it now.
[20:48] <pasteeater> damn. i was just about to give him a crappy answer...
[21:19] <gnarface> is there a way to select a specfic camera angle when encoding a VOB file that has multiple?   the command line i'm currently using seems to try to encode both at once - resulting in an avi that flickers back and forth between them rather disruptively
[21:19] <gnarface> sorry, i mean when *transcoding* a VOB file that has multiple - to something else (like an mpeg4 avi)
[21:21] <gnarface> this, for example works for me great when the VOB only has one camera angle:  for BLAH in 1 2; do ffmpeg -i [VOB FILE] -f avi -vcodec mpeg4 -pass $BLAH -s 320x240 -sameq -aspect 4:3 -g 300 -bf 2 -acodec ac3 -sameq [divx file] -map 0:0 -map 0:2; done
[21:22] <gnarface> if someone knows that there is NOT a way to select camera angles, i'd appreciate knowing that so i can look for an alternate solution
[22:04] <chaosblackdragon> Is it possible to recorde a live stream to multipl files in 10 min chunks ?
[22:15] <\DSAFEW\> I want to stream to justin.tv/twitch.tv, and I have tried fiddling with ffmpeg quite a bit, but during each of my tests within a minute the audio is noticeably slower than the video, async seems to do nothing, as sometimes the program starts and the results are already desynched
[22:21] <\DSAFEW\> sample output http://paste.pocoo.org/show/562108/
[22:22] <\DSAFEW\> current command: ffmpeg -f x11grab -s "$inres" -r "$fps" -i :0.0"${offset}" -f alsa -async 2 -ac 2 -i pulse -vcodec libx264 -vpre "$qual" -s "$outres" -acodec libmp3lame -ab 96k -ar 44100 -threads 0 -f avi "${output_file}"
[22:22] <\DSAFEW\> can't get -vsync drop to work, which is why I upgraded to .10, tried almost everything with the older stable version
[00:00] --- Wed Mar  7 2012


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