[Ffmpeg-devel-irc] ffmpeg.log.20111119

burek burek021 at gmail.com
Sun Nov 20 02:05:02 CET 2011


[00:02] <iive> Freakshow: how can I help you?
[00:39] <FunkyELF> any Fedora users here?  even after I did a "sudo yum install -y faac" I'm getting this.... "Unknown encoder 'libfaac'"
[00:41] <sacarasc> Did you compile ffmpeg with faac?
[00:42] <FunkyELF> sacarasc, I didn't compile it at all
[00:42] <FunkyELF> I installed it with yum
[00:44] <sacarasc> Well, you'd have to compile it to get it to work with faac.
[00:44] <FunkyELF> sacarasc, doh
[05:52] <shevy> anyone knows this error:
[05:52] <shevy>   ffmpeg: relocation error: ffmpeg: symbol av_demuxer_open, version LIBAVFORMAT_53 not defined in file libavformat.so.53 with link time reference
[06:10] <shevy> hmm WARNING: library configuration mismatch
[08:20] <pinkette> does ffmpeg support aac encoding?
[08:38] <relaxed> pinkette: yes
[08:38] <pinkette> relaxed since when
[08:39] <relaxed> it's had support for libfaac for a while, plus now it has an internal aac encoder too.
[08:40] <relaxed> or libvo-aacenc
[08:42] <pinkette> what is the ffmpeg.exe command to  convert to aac
[08:43] <relaxed> ffmpeg -i input.wav -acodec aac -ab 192k output.m4a
[08:43] <pinkette> does it only support from .wav file?
[08:44] <relaxed> you can find recent windows builds here http://ffmpeg.zeranoe.com/builds/
[08:45] <relaxed> pinkette: no, it's supports just about anything you can throw at it.
[08:45] <pinkette> did not work:  R:\>ffmpeg -i E:\1.vob -acodec aac -ab 192k E:\output.m4a
[08:46] <pinkette> encoder 'aac' is experimental and might produce bad results.
[08:46] <pinkette> Add '-strict experimental' if you want to use it.
[08:46] <pinkette> Or use the non experimental encoder 'libvo_aacenc'.
[08:46] <relaxed> use libvo_aacenc
[08:46] <pinkette> is libvo_aaenc  a  .exe file?
[08:47] <relaxed> R:\>ffmpeg -i E:\1.vob -acodec libvo_aaenc -ab 192k E:\output.m4a
[08:47] <pinkette> i see
[08:47] <relaxed> er, that shoud be libvo_aacenc (forgot the c)
[08:48] <pinkette> what is the difference between  "aac" and "libvo_aacenc"?
[08:48] <relaxed> add "-sn -vn" after the input to ignore video and subtitles
[08:48] <pinkette> 1.vob is audio-only file
[08:49] <pinkette> wow it worked: how come so many app have problem with doing this
[08:50] <relaxed> I believe libvo_aacenc is google's open source encoder, while 'aac' is ffmpeg's encoder but it's still (too) new
[08:51] <pinkette> then why is  libvo_aacenc in  ffmpeg.exe ?
[08:51] <pinkette> shouldn't they have their own .exe file
[08:52] <relaxed> you can compile ffmpeg with support of external encoding libraries such as libmp3lame (mp3), libx264 (h264 encoding), etc...
[08:53] <pinkette> ffmpeg version N-34906-g4e7b3ef, Copyright (c) 2000-2011 the FFmpeg developers
[08:53] <pinkette>   built on Nov 16 2011 12:35:07 with gcc 4.6.2
[08:53] <pinkette> is this latest version
[08:53] <relaxed> you probably have a static binary so all the external libs are included in the ffmpeg.exe binary
[08:54] <pinkette> what is official file extension of aac
[08:54] <pinkette> why can't acc be always same like mp3
[08:55] <relaxed> you can encode to raw aac buy using the .aac extension
[08:55] <relaxed> by*
[08:56] <pinkette> does ffmpeg support  muxing to different container
[08:56] <pinkette> without encoding video/audio
[08:56] <relaxed> yes
[08:57] <relaxed> ffmpeg -i INPUT -vcodec copy -acodec copy OUTPUT.mkv
[08:57] <pinkette> only problem is: what is "input file" is  splitted vob/ifo files
[08:58] <pinkette> if*
[08:59] <relaxed> what are you trying to do? you ripped a dvd and now you want what?
[08:59] <pinkette> i want  untouched mpeg2 dvd video and untouched ac3 file  into   file.mkv
[08:59] <pinkette> from splitted ifo/vob files
[09:02] <pinkette> you ripped a dvd and now you want what?   no i did not rip a dvd
[09:02] <relaxed> If you know which vobs are the movie- ffmpeg -i concat:1.vob\|2.vob\|3.vob -vcodec copy -acodec copy output.mkv
[09:03] <pinkette> no
[09:03] <pinkette> i don't nkow
[09:04] <pinkette> it has VTS_04_1  to VTS_04_8    but it has 3 videos  in them
[09:05] <pinkette> actually 9
[09:05] <relaxed> you can grab the title(s) with mplayer -dumpstream -dumpfile title1.vob -dvd-device /path/to/vobs dvd://1
[09:06] <pinkette> why can't ffmpeg do it?
[09:06] <pinkette> handbrake  breaks them down nicely  and i was told handbrake uses ffmpeg
[09:07] <pinkette> http://www.imagebam.com/image/e19f4e160093951
[09:07] <relaxed> just about every encoding software on the interweb uses ffmpeg libs for decoding/encoding
[09:07] <pinkette> can you see that picture?
[09:08] <relaxed> yes. what about it?
[09:09] <pinkette> it automatically and nicely divides  video files from  splitted vob/ifo files
[09:10] <pinkette> so how would i do that in this format   ffmpeg -i INPUT -vcodec copy -acodec copy OUTPUT.mkv
[09:10] <relaxed> handbrake must be able to do what you want.
[09:10] <pinkette> it doesn't do muxing
[09:12] <relaxed> I've given you a solution with the tools I know.
[09:13] <pinkette> so ffmpeg alone cannot do that?
[09:14] <relaxed> ffmpeg cannot read dvds
[09:17] <pinkette> how does handbrake read dvds then
[09:19] <pinkette> does ffmpeg aac encoder support  variable bitrate
[10:14] <pinkette> does ffmpeg.exe support variable bitrate for aac encoding?
[16:42] <naxa> hi! tried `ffmpeg -i x.ogv -vcodec libtheora -acodec libvorbis -sameq -s qvga x_qvga.ogv`, but the output has very visible artifacts. what am i doing wrong, what is the preferred way to do it?
[16:43] <khali> naxa: I don't recommend using -sameq, it usually doesn't do the right thing
[16:43] <sacarasc> -sameq probably doesn't do what you think it does.
[16:43] <khali> naxa: check the bitrate of the intput file and the bitrate of the output file
[16:43] <sacarasc> Also, you could probably use -acodec copy
[16:44] <khali> yeah, I was about to suggest the same
[16:48] <naxa> sacarasc: I've tried -acodec copy and -vcodec copy but then it wouldn't be resized
[16:49] <sacarasc> -acodec copy should work, but -vcodec copy won't work with resizing.
[16:49] <sacarasc> You're not resizing the audio, just the video.
[16:49] <naxa> sacarasc: I basically would like to make the video 1/4 size as the original without change in visible quality
[16:49] <naxa> sacarasc: you are right with acodec i see.
[16:50] <naxa> didn't this channel included a link to some faq earlier?
[16:50] <naxa> in the topic info.
[16:50] <naxa> *include
[16:54] <naxa> if I 1/4 the dimensions, how should I adjust the bitrate in case of libtheora?
[16:54] <khali> naxa: http://ffmpeg.org/faq.html
[16:54] <naxa> khali: yes I know that but it didn't have my question :)
[16:56] <naxa> khali: anyway, thank you very much!
[17:05] <khali> naxa: well obviously video bitrate is proportional to the surface
[17:05] <khali> for a given quality, I mean
[17:05] <khali> so 1/4 surface -> 1/4 bitrate for the same quality
[17:06] <khali> that being said, you often want higher quality for smaller videos because they are watched from closer
[17:06] <khali> that's my experience at least
[17:06] <naxa> khali: so i should do the same operation with the bitrate as with the dimensions ("aggregated")?
[17:06] <naxa> khali: ok thanks! 
[17:06] <khali> not sure what you mean with aggregated
[17:07] <khali> naxa: what's your input video bitrate and resolution?
[17:07] <naxa> khali: I'm trying to mean that one thing if i do *0.5 to the height and another if i do *0.5 to the width so overall it's *(0.5^2)
[17:07] <khali> =0.25
[17:08] <naxa> khali: i think i just managed to do it with like this thank you!
[17:08] <Freakshow> iive: I'm an ass... my wife got my attention after I tried to get yours yesterday. Sorry... is there any significant difference in the way that ffmpeg handles rtmp vs the way that librtmp does?
[17:08] <Freakshow> rather ffmpeg + librtmp
[17:09] <iive> rtmp works with encrypted streams. It's also kept up to date with the latest obfuscations
[17:09] <Freakshow> I presume you mean librtmp?
[17:10] <iive> yes
[17:11] <Freakshow> ok, cool... so it sounds as if this error condition I'm seeing (on the ingest side) could simply be a manifestation of using ffmpeg standard rtmp output
[17:12] <Freakshow> I'll try building 0.8.6 + librtmp and see if I can reproduce
[17:13] <Freakshow> 2.4 actually builds now with SYS=posix
[17:13] <Freakshow> :P
[17:13] <Freakshow> however, I'll be honest, I haven't submitted my original bug report just yet
[17:14] <Freakshow> is tcpdump info useful or is that overboard?
[17:36] <iive> no idea.
[17:57] <Freakshow> great... thanks!
[18:15] <fris> which repo is the recommended to install for latest stable
[18:29] <Freakshow> fris: http://ffmpeg.mplayerhq.hu/download.html#release_0.8
[19:49] <BlackBishop> damn, I wish I'd have 0.8 :(
[19:50] <colemana> http://pastebin.com/qKUeUmLn
[19:50] <colemana> I am trying to use libx264 - but it seems my a/v sync is off.
[19:51] <colemana> Can anyone provide assistance?  I am using the most recent git version.
[19:53] <colemana> I suspect maybe that my commands might be out of order?  
[20:17] <robertzaccour> is qt-start in real time?
[20:18] <sacarasc> qt-faststart?
[20:18] <sacarasc> It does it in quicker than real time.
[20:18] <robertzaccour> sacarasc: thats what I meant sorry
[20:19] <robertzaccour> sacarasc: so with qt-faststart would I be able to basically make my computer screen into a display while capturing audio/video from my ps3 with my hd-pvr?
[20:20] <sacarasc> All qt-faststart does is move the moov atom from the end of an MP4 file and puts it at the start...
[20:23] <robertzaccour> sacarasc: oh ok. I had the idea of somehow combining the capturing of my ps3 gameplay through my hd-pvr and somehow putting it into a folder that I could open and display in real time and turning my computer screen into my ps3 game display
[20:23] <robertzaccour> sacarasc: I capture my hd-pvr with cat /dev/video1 > screencast.avi and didn't know if displaying in real time was possible or not
[20:25] <robertzaccour> I'm pretty sure I'm living in a fairy tale land but who knows
[20:25] Action: sacarasc shrugs.
[20:25] <robertzaccour> ok thanks anyhow
[21:15] <Wildride> does ffmpeg support joining or splitting video files?
[21:16] <sacarasc> Yes, but joining might not work very well, depending on codec/container.
[21:17] <Wildride> but splitting works well?
[21:17] <khali> yes, splitting works, using -t and -ss
[21:17] <Wildride> sacaras  i am only joining files that are splitted from original files that author did
[21:18] <Wildride> i am not joining 2 random video files
[21:18] <khali> sacarasc: as far as I know, ffmpeg doesn't support joining at all... do you know of a way I ignore?
[21:19] <Wildride> khali ignore what
[21:20] <sacarasc> khali: The concat protocol.
[21:26] <hackeron> hey, I'm new to C and compiling - I'm trying to make this work with latest ffmpeg: https://github.com/bluecherrydvr/solo6x10/blob/master/utils/bc-record.c -- I have #include <libavformat/avformat.h> in the file, yet I'm getting bc-record.c:(.text+0x716): undefined reference to `av_guess_format' when I try to compile - I definitely have av_guess_format in avformat.h: -- any ideas?
[21:29] <Mavrik-> hackeron, that's not for header files
[21:30] <Mavrik-> hackeron, the error means it can't find the code - meaning it didn't link  the .so or .a library
[21:30] <Mavrik-> fix your library path
[21:31] <hackeron> Mavrik-: hmm, how? - is that LDFLAGS? - that's set to -lavformat
[21:34] <hackeron> Mavrik-: like this? < cc -o bc-record bc-record.c -L/usr/lib/libavformat.so --- that shows the same error
[21:41] <hackeron> ah, think I'm getting somewhere - if I do cc -o bc-record bc-record.c -L/usr/lib/ -lavformat -- I get /usr/bin/ld: note: 'avcodec_find_encoder@@LIBAVCODEC_53' is defined in DSO /usr/lib/libavcodec.so.53 so try adding it to the linker command line - hmm, how do I do that?
[21:45] <Mavrik-> hackeron, -L/usr/lib/
[21:47] <hackeron> Mavrik-: ah, thanks, it compiles with: cc -o bc-record bc-record.c -L/usr/lib/ -lavformat -lavcodec -lavutil
[21:49] <hackeron> Mavrik-: but now when I run it says Error finding video encoder - the line is codec = avcodec_find_encoder(video_st->codec->codec_id); --- video_st is static AVStream *video_st;
[21:49] <Mavrik-> obviously you don't have the video encoder for the id compiled in.
[21:52] <hackeron> Mavrik-: ah, bingo! - I installed libavformat-extra-53 and now it's working :P -- thank you!
[21:52] <Mavrik-> ^^
[22:07] <Wildride> what is the difference between -acodec libvo_aacenc   over  -acodec aac  ?
[22:10] <Mavrik-> different encoders
[22:10] <Wildride> what exactly is  libvo_aacenc
[22:10] <Mavrik-> libvo_aacenc is the AAC encoder used in Android, aac is an experimental (and broken) implementation that's part of ffmpeg
[22:10] <Wildride> i see
[22:11] <Mavrik-> there's also libfaac which was widely used before libvoo_aacenc was added
[22:11] <Wildride> does ffmpeg support  faac/neroaac/itunesaac
[22:11] <sacarasc> It does support faac, if you compile yourself.
[22:15] <Mavrik-> Wildride, faac yes, neroaac and itunesaac aren't libraries so no.
[22:15] <Wildride> what -acodec "name"  is for  faac?
[22:16] <sacarasc> If you didn't compile yourself, you won't have faac enabled.
[22:16] <sacarasc> But I think it's libfaac or just faac.
[22:17] <Wildride> is aac even better than mp3?
[22:17] <Mavrik-> libfaac.
[22:19] <Wildride> how come ffmpeg cannot read from vob/ifo 
[22:21] <sacarasc> Wildride: faac is a crap encoder, but ~= to mp3lame...
[22:21] <Wildride> d
[22:22] <Wildride> what is "~="
[22:22] <sacarasc> Approximately equal to.
[22:27] <CapsuleNZ> Hey guys, I have a question about converting .aiff to .raw. I've tried already but I get a output error (I'm doing this from CLI) - Here my command + output http://pastebin.com/X09jJgfn
[22:28] <sacarasc> Try -f s16le
[22:30] <Wildride> sacarasc  is nero-aac the best?
[22:30] Action: sacarasc shrugs. I don't have the data myself...
[22:30] <sacarasc> I just know faac is old and poo.
[22:31] <Mavrik> mhm
[22:31] <Mavrik> I just can't seem to find any info for libvo_aacenc
[22:32] <Wildride> Mavrik same here
[22:32] <Wildride> then how did you know it is by google-android?
[22:43] <Wildride> does ffmpeg have h264 standard encoder?
[22:43] <sacarasc> libx264.
[22:44] <Wildride> is that new?
[22:44] <sacarasc> Not really.
[22:44] <Wildride> is it better than x264?
[22:45] <Wildride> x264 is awful and inconstant
[22:45] <sacarasc> It is x264.
[22:45] <Wildride> oh, so it's not ffmpeg's
[22:46] <Wildride> because i saw  ffmpeg(mpeg4) and ffmpeg(mpeg2)  and x264 in  handbrake
[22:52] <Xd7mT> hello
[22:53] <Xd7mT> question: i need to get good quality from raw yuv format to mpeg4 (default) in ffmpeg. what option do u recommend?
[22:54] <Xd7mT> mb several options
[22:54] <khali> Xd7mT: the FAQ has suggestions for high quality MPEG4
[22:54] <khali> http://ffmpeg.org/faq.html#Which-are-good-parameters-for-encoding-high-quality-MPEG_002d4_003f
[22:54] <Wildride> xd7mt when you say mpeg4 ; you mean  libx264
[22:55] <Xd7mT> khali: yes. already
[22:55] <Xd7mT> its default choose of ffmpeg on me
[23:11] <Wildride> what is ffmpeg command to convert a audio into  wav
[23:18] <Xd7mT> i am used -b 4000k option to get good quality. is it right? only one trouble: big size in compare to quality.
[23:23] <Xd7mT> anyway 1000k is too little. i have very bad quality with default settings
[23:25] <Xd7mT> how to get 1 hour of video in ~1000 MB with good quality? FAQ doesnt help
[23:37] <Xd7mT> mb need not constant value?
[23:40] <Mavrik> (1000 / 60 * 60) * 8 = bitrate in Mbit/s you need
[23:42] <Xd7mT> i see in vlc player on codecs page that bitrate isnt constant
[23:43] <Mavrik> of course it isn't. But that's what you need to target if you want a 1GB file for an hour of video.
[23:56] <Xd7mT> Mavrik: you think 8000k would be fine?
[23:58] <Mavrik> that's going to make you a 3.6GB file.
[23:59] <Xd7mT> ok. thx
[00:00] --- Sun Nov 20 2011


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