[Ffmpeg-devel-irc] ffmpeg.log.20111223

burek burek021 at gmail.com
Sat Dec 24 02:05:02 CET 2011


[00:35] <mfwitten> I used VLC's record feature to dump a stream; while dumping this streaming, some kind of I/O latency kicked in, and a frame froze on screen for a second. Unfortunately, when playing back the dumped file in VLC or using it in kdenlive, this frozen frame gets repeated (VLC also drops the underlying audio, and kdenlive's looses the sync between audio and video as a result). Interestingly, though, mplayer can play this video without any ...
[00:35] <mfwitten> ... troubles (No frozen frames, no lost audio, no unsyncronicity). I think the problem is that the frozen frame is somehow encoded with the wrong duration (or something similar), and mplayer must be ignore this frame-specific duration setting or something. Does anybody know how I might `normalize' the duration of this frame?
[00:57] <mfwitten> No? Nobody?
[00:58] <mfwitten> FOSS strikes again with its almost but not quite good enough state
[00:58] <mfwitten> What a shame.
[00:58] <mfwitten> I'd rather have nothing than something that pretends to work.
[00:58] <mfwitten> Bubbye
[01:00] <newl> bye
[03:13] <_hc> funny how people like mfwitten thing everyone owes them something
[04:42] <felippeth> Hey there, i've been working on a project, and i need to convert a .mov video to .flv. it runs and does the job when i type straight into the command line, but for some reason nothing happens when i do it through php shell_exec/exec. here's what i've tried:  shell_exec("ffmpeg -i $src -ab 56 -ar 44100 -b 200 -r 15 -s 320x240 -f flv roamey_php/vids/videos/flvs/$finalname.flv 2>&1")
[04:43] <felippeth> can someone point me at the right direction pls?
[04:43] <caytchen> thats more of a php problem then.
[04:43] <caytchen> note that for most php installations, you won't be able to use shell_exec
[04:44] <caytchen> and even if you can, you will likely be restricted to a limited privileges user account and possibly even chrooted.
[04:44] <felippeth> it is.. but php is running other exec's or shell_exec's such as "ls"
[04:44] <felippeth> everything seems to be working apart from ffmpeg thought php
[04:45] <newl> felippeth: does touch work in it?
[04:45] <newl> and try full path to the ffmpeg
[04:46] <felippeth> you mean like shell_exec("usr/bin/ffmpeg -i $src -ab 56 -ar 44100 -b 200 -r 15 -s 320x240 -f flv roamey_php/vids/videos/flvs/$finalname.flv 2>&1") ?
[04:47] <newl> and see if   shell_exec("touch aaaaa"); works
[04:47] <caytchen> with an extra /, I guess.
[04:48] <caytchen> the client or server or any other random component in the chain from http request to ffmpeg will likely buzz out with a timeout years before ffmpeg has finished converting, by the way ;o
[04:48] <newl> i thought he was just doing it on cli?
[04:49] <newl> if he is using $src i hope it is in a script or src is defined
[04:49] <caytchen> I didn't read anything about running php from cli so I assumed its going through a webserver.
[04:49] <newl> ...'job when i type straight into the command line,..'
[04:50] <caytchen> thats referring to the ffmpeg command line ;o
[04:50] <newl> who knows - he ain't telling ;)
[04:52] <felippeth> sorry, was just trying some of the suggestions
[04:52] <felippeth> so it seems that touch isnt doing it
[04:52] <felippeth> i mean its weird cuz it works for some stuff
[04:53] <felippeth> ls or ll for example
[04:53] <felippeth> im trying all this on SSH
[04:53] <caytchen> writing privileges are a wholly different beast to reading
[04:53] <felippeth> to my server
[04:54] <felippeth> hmm it just doesnt give much sense to be able to write through SSH and not php
[04:54] <caytchen> you're not writing through SSH
[04:55] <caytchen> php is possibly restricting itself before executing anything and not running from the account you're logged in with
[04:55] <felippeth> i mean thats my access to the server
[04:56] <caytchen> try <?php echo shell_exec("id"); ?>
[04:57] <felippeth> worked
[04:58] <felippeth> got response
[04:58] <caytchen> well, whats the output - is it the same user as the one you're logged in as?
[04:58] <felippeth> uid, gid and groups
[04:58] <felippeth> yup
[05:01] <felippeth> what a nightmare
[05:14] <felippeth> caytchen: the client or server or any other random component in the chain from http request to ffmpeg will likely buzz out with a timeout years before ffmpeg has finished converting, by the way 
[05:15] <felippeth> would you say that isnt the most reliable way of doing what i want?
[05:20] <caytchen> you don't want a webserver to do audio video conversion
[05:23] <caytchen> given the time and space complexity of even a simple conversion you could have a single user pressing f5 easily DoS your server.
[05:30] <felippeth> hmm i see, what other alternative would i have though? 
[05:30] <caytchen> depends. what are you trying to do?
[05:31] <felippeth> user uploads video, it gets converted so it plays on flash. and video can be shared
[05:31] <felippeth> youtube sort of thing
[05:32] <caytchen> i'd write something that acts as a server in the background and converts files as capacity allows and then have the PHP talk to the server
[05:33] <caytchen> that would require you to use C or C++ though.
[05:33] <felippeth> well and probably full access to a shared server
[05:33] <felippeth> which isnt the case
[05:33] <caytchen> heh, you want that anyway.
[05:34] <caytchen> you can't run ffmpeg from very limited webspace hosting.
[05:34] <felippeth> nah my hosting is pretty good i'd say
[05:35] <felippeth> and obviously if they had ffmpeg installed, i believe that expect ppl to use so
[05:35] <felippeth> but it does make sense what you're saying
[05:36] <caytchen> what is your current hosting situation? sounds like shell access. I thought those died out years ago.
[05:36] <felippeth> u know site5?
[05:36] <caytchen> uhm, nope
[05:37] <caytchen> but guessing from their repertoire, you want to have at least a vps.
[05:37] <felippeth> obviously there are better options, but they do a pretty good deal taking quality/ price into account
[05:38] <felippeth> yeah
[05:39] <caytchen> if you have a VPS, you can run a server in the background just as I described, no problem.
[05:39] <felippeth> problem is, i'm still not quite using it so much that it justifies paying that much money 
[05:39] <felippeth> i kinda want to have a prototype of what that is
[05:40] <felippeth> and when it comes to take it to the next step, do so
[05:46] <felippeth> alrite, thanks for the help
[07:54] <Akinatopsia> hey anyone around?
[08:19] <Akinatopsia> anyone alive?
[09:05] <TimN> ZZzzzzz
[09:05] <frogs> i have problem with recent commit, "use logical cpus as thread count", it's break my compile
[09:07] <Akinatopsia> can someone help me with a cropping issue?
[09:16] <Wizord> Akinatopsia, don't ask to ask
[09:17] <frogs> http://pastebin.com/raw.php?i=UdE8YWsb
[09:18] <Akinatopsia> i'm using ffmpegx for mac. everything encodes fine, but it seems to ignore any cropping settings i have
[09:19] <Akinatopsia> am i doing something wrong? :\
[09:45] <cbsrobot> frogs: what os and compiler?
[09:46] <frogs> freebsd 8.2 with clang 3
[09:46] <frogs> i build mplayer/ffmpeg/x264 daily so that breakages are found within one day
[09:49] <frogs> it just needs to include types.h before sysctl.h
[09:50] <cbsrobot> frogs: that's what i thought too - but I'm not sure it's a proper solution
[09:51] <cbsrobot> second thought - send a patch
[09:51] <frogs> i am, to here
[09:51] <frogs> have to find committer
[09:52] <cbsrobot> it's pulled from libav
[09:53] <frogs> is libavcodec still under control of ffmpeg? since the ffmpeg wars
[09:53] <cbsrobot> frogs: both sides add stuff
[09:59] <frogs> cbsrobot: does that faction have a channel on this network?
[09:59] <cbsrobot> frogs: yes - I already reported it in your name
[10:00] <frogs> what's the name of them? i would join
[10:00] <cbsrobot> but you can join #libav-devel - the committer is jannau - if i'm not mistaken
[10:00] <frogs> cbsrobot: i thought libavcodec was still under control of the ffmpeg faction
[10:00] <cbsrobot> well ffmpeg pulls also from libav
[10:03] <mendel_> guys I want to extract the dvb-teletext stream, I was hoping the -map 0:2 would do, but that isn't working
[10:03] <mendel_> anyone with a better idea?
[10:05] <Akinatopsia> cbsrobot, could you help with my problem?
[10:05] <cbsrobot> Akinatopsia: use the command line
[10:06] <Akinatopsia> uhh how do i do that?
[10:10] <mendel_> anyone? see http://ffmpeg.org/trac/ffmpeg/ticket/531 for a ticket by someone else
[10:11] <cbsrobot> Akinatopsia: maybe ask in http://forum.videohelp.com/forums/34-ffmpegX-general-discussion
[16:13] <albacker> how do i extract audio from a .flv file?
[16:15] <cbsrobot> albacker: I thinks it's covered in the manual
[16:18] <cbreak-work> what's the best stream format to pipe uncompressed audio/video between ffmpeg code?
[16:18] <albacker> ffmpeg -i myfile.flv -vn -acodec copy mymp3.mp3 didn't work
[16:18] <albacker> LAVF_header: av_find_stream_info() failed
[16:19] <cbreak-work> albacker: if you have mplayer you can try -dumpaudio or -ao pcm (see man page for details)
[16:21] <cbsrobot> albacker: does your flv contain audio ?
[16:21] <cbsrobot> pastebin the output of: ffprobe myfile.flv
[16:28] <albacker> http://pastebin.com/RC29PAZb
[16:28] <albacker> cbsrobot, ^
[16:41] <cbsrobot> albacker: so its aac - not mp3
[16:41] <cbsrobot> what do you want at the end ? aac or mp3 ?
[16:43] <albacker> mp3
[16:44] <cbsrobot> try: ffmpeg -i myfile.flv -vn -acodec libmp3lame -ab 128k mymp3.mp3
[16:45] <albacker> it says
[16:45] <cbreak-work> reencoding will cost you quality.
[16:45] <albacker> unknown encoder libmp3lame
[16:46] <cbsrobot> albacker: you need to compile ffmpeg with liblame support
[16:47] <albacker> that's too much of a hussle.
[16:47] <albacker> i just wanted to rip some mp3s for my travel in 1h.
[16:49] <cbsrobot> albacker: git pull; ./configure --enable-gpl --enable-version3 --enable-nonfree --enable-libmp3lame --enable-libfaac; make -j 8; make install; <- takes only a few minutes !
[16:49] <cbsrobot> of course you need to install liblame too
[16:49] <cbreak-work> you could try to get the aac
[16:50] <cbreak-work> maybe your player supports that
[16:54] <albacker> i'll try ripping aac
[16:54] <albacker> and see if my device will play it
[16:55] <albacker> everything went better than excepcted
[16:55] <albacker> thanks everone
[16:55] <albacker> everyone
[17:11] <Sentynel> hi folks, got a minor build issue with  the git version - it'll only build in a clean build directory. if I update and build again in the same directory without cleaning, it fails with "make: *** No rule to make target `doc/../tests/fate_config.sh.template', needed by `doc/fate.html'. Stop."
[23:11] <Akinatopsia> i'm using ffmpegx for mac. everything encodes fine, but it seems to ignore any cropping settings i have
[23:12] <Akinatopsia> am i doing something wrong? :\
[23:16] <cbsrobot> Akinatopsia: did you ask in the ffmpegx forum ?
[23:16] <Akinatopsia> it wouldn't let me sign up :\
[23:16] <cbsrobot> hehe - ok
[23:17] <cbsrobot> I can only help you with ffmpeg - not with the gui
[23:19] <treund> what is the benefit of a ffmpeg gui?
[23:22] <Akinatopsia> how do i get into the code thing then?
[23:25] <cbsrobot> Akinatopsia: have you ever used xcode, gcc end such things ?
[23:26] <Akinatopsia> a little
[23:27] <cbsrobot> git ?
[23:27] <cbsrobot> lets say - theres a hard way (compiling everything yourself) - and theres the easy way (extracting ffmpeg binary from ffmpegx)
[23:27] <cbsrobot> what do you prefer ?
[23:28] <Akinatopsia> neither
[23:28] <Akinatopsia> i choose gui
[23:28] <Akinatopsia> lol
[23:28] <cbsrobot> ok easy way it is
[23:28] <Akinatopsia> i know how to use terminal
[23:28] <Akinatopsia> if that counts
[23:29] <cbsrobot> in the ffmpegx bundle is somewhere the ffmpeg binary
[23:29] <cbsrobot> copy it somewhere your $PATH can see it
[23:30] <cbsrobot> on terminal type: echo $PATH
[23:31] <cbsrobot> I suggest: /usr/local/bin/
[23:31] <Akinatopsia> hmm sec
[23:31] <cbsrobot> so copy the binary there - it's mandatory, but more convenient
[23:31] <cbsrobot> so:
[23:33] <caytchen> .. and if you can't find the binary and its linked in, write to gpl-violations ;)
[23:35] <cbsrobot> its smthing like:
[23:35] <cbsrobot> sudo cp /Applications/FFmpegX.app/Contents/resources/ffmpeg /usr/local/bin/
[23:35] <cbsrobot> *Resources
[23:37] <cbsrobot> then what file you want to convert in what format ?
[23:37] <Akinatopsia> mp4
[23:37] <Akinatopsia> converting to the same format
[23:37] <Akinatopsia> just fixing the aspect ratio and cropping
[23:38] <cbsrobot> ah np
[23:38] <cbsrobot> so what version of ffmpeg you have ?
[23:38] <Akinatopsia> 0.0.9y
[23:38] <cbsrobot> not ffmpegX
[23:38] <cbsrobot> ffmpeg
[23:38] <cbsrobot> type: ffmpeg
[23:38] <cbsrobot> and hit enter
[23:40] <cbsrobot> Akinatopsia: alive ?
[23:44] <u0m3> not sure this is the place for such questions but here it goes: does anyone know where I could find some documentation on ffmpeg api - the audio resampling part - swresample ? or some examples would be even better
[23:46] <caytchen> u0m3: only documentation there is is the doxygen for the public api and reading the source code
[23:47] <caytchen> u0m3: note that besides swresample, theres also ReSampleContext in avcodec
[23:51] <u0m3> caytchen: I tried to get what info I need from ffmpeg.c but it seems it's out of my league... didn't even manage to find where the flags (like: -acodec -ar etc) are processed... thanks for the ReSampleCOntext tip
[23:51] <caytchen> oh, are you trying to use ffmpeg the command line tool or ffmpeg the library?
[23:53] <Mavrik> u0m3, sadly that's the best there is... I suggest you grep through ffmpeg.c for swresample use and track back from there
[00:00] --- Sat Dec 24 2011


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