[Ffmpeg-devel-irc] ffmpeg.log.20111203

burek burek021 at gmail.com
Sun Dec 4 02:05:03 CET 2011


[00:32] <defaultro> can ffmpeg do the slow motion that twixter does?
[05:24] <stev3> hey - im rendering the same file, with the same commandline options on both windows and ubunutu, but  the linux version returns a file much larger - im thinking they may have different default values for options im not specifying maybe? 
[05:24] <stev3> ffmpeg -i test.avi -f flv -ab 128k -ar 44100 -b 800k test.flv
[10:02] <sjuxax> Hello. I have:  ffmpeg -i 00001.MTS -threads 0 -s 1024x576 -c:v wmv2 -b:v 3000k -c:a libmp3lame -aq 0 -y out.wmv, but I get standard incorrect parameters error when I attempt to encode. Pasting full output momentarily...
[10:03] <sjuxax> http://dpaste.com/665337/
[10:04] <sjuxax> DEVSD  wmv2            Windows Media Video 8, so the codec support is present
[10:08] <relaxed> sjuxax: remove -threads 0
[10:09] <sjuxax> relaxed: Thanks.
[10:09] <sjuxax> That works now.
[10:11] <sjuxax> Is there a reason ffmpeg wants to error there when it could just ignore the request for automatic threading, since it's not supported? I know you could say that you don't want someone to mistakenly assume that the computer is automatically deciding how many threads to use, but that doesn't seem like it's worth the cost. It seems ffmpeg is much stauncher than everything else and that leads to a lot of errors with its usage (parameter order, for instance, i
[10:24] <uclinux> is it possible to fade a watermark/image in?
[10:29] <dango> what is the difference between stereo and joint stereo
[10:32] <relaxed> uclinux: yes, look at the overlay filter in the man page or website.
[10:33] <uclinux> okay cool, I can get the whole video to fade in and out but I am having trouble getting just the watermark to fade
[10:33] <relaxed> oh, hmm
[10:34] <uclinux> i think the overlay filter will fade the whole video...correct?
[10:36] <relaxed> I'm not sure what you mean. What are you doing?
[10:37] <uclinux> video plays, water mark fades in then fades out,
[10:37] <uclinux> i can do it with avisynth
[10:38] <uclinux> but i would much rather approach this problem with ffmpeg for a number of reasons
[10:39] <relaxed> the filter system is powerful but I'm not sure how do that 
[10:40] <uclinux> yup, pretty much the consensus. theres a piece of c code floating around to do it but it was for an older version of ffmpeg. 
[10:40] <uclinux> pip.c
[10:42] <relaxed> there's the fade filter
[10:45] <uclinux> I'm having trouble applying the fade filter to "only" the watermark
[10:48] <relaxed> uclinux: It might be something like: movie=logo.png [logo]; [in][logo] overlay=10:main_h-overlay_h-10,fade=.... [out]
[10:49] <uclinux> thats like exactly what i'm using. I am fairly familiar with chains
[10:49] <uclinux> relaxed: it actually applies the fade to the clip, not "only" the watermark
[10:51] <uclinux> relaxed: its a tricky one, this would save like 200 man hours probably
[10:52] <relaxed> did you try  movie=logo.png,fade=... [logo]; [in][logo]...
[10:54] <uclinux> relaxed: When I do that I get no image overlay
[10:54] <uclinux> http://pastebin.com/ttWrimHy is what i tried
[10:55] <mshadle_> I am trying to convert some really old syntax/ffmpeg commands and such that someone developed a while ago. bounty is available for help. :p http://pastebin.com/DpjqLVFd
[10:56] <uclinux> mshadle_: i can do this after I finished what I'm working on
[10:57] <uclinux> I'm pretty booked at the moment lol
[10:57] <mshadle_> awesome! the vhook pieceis the trickiest i think. and i might fall asleep. i left my email in the pastebin though. so if i don't reply, email me and let me know :)
[10:58] <uclinux> yeah, I'm dealing with a vhook/watermark issue right now
[10:58] <uclinux> idk if there is a solution to mine
[10:58] <mshadle_> cool
[10:58] <mshadle_> i *think* this i a simple one
[10:58] <uclinux> i'll shoot you an email in the AM
[10:59] <mshadle_> thanks. these are 8 core webservers. all they do is nginx/php and encoding when something is in the queue. so they can be given plenty of CPU resources
[11:00] <uclinux> relaxed: thanks for help...I think i will end up with a custom solution :/
[11:04] <relaxed> uclinux: Use two commands and on the first one loop the input of the png adding the fade with the output of %06d.png. Then use %06d.png as your overlay input.
[11:05] <relaxed> assuming you can use %06d.png as the input
[12:25] <burek> dango, the diff is compression only
[12:25] <burek> no loss of quality
[12:25] <dango> huh? all lossy compression = loss of quality
[12:26] <JEEB> yes, to a level :)
[12:26] <dango> what is the difference between stereo and joint stereo? and why is it only option in mp3
[12:27] <burek> http://www.richardfarrar.com/what-is-joint-stereo/
[12:27] <burek> there is also lossless compression, called gzip, you know?
[12:28] <JEEB> of course
[12:29] <JEEB> just like ffvhuff, x264's H.264's lossless profile and such for video, and FLAC, wavpack and such for audio
[12:30] <dango> is mp3 the only lossy audio codec that use joint stereo
[12:31] <JEEB> it can be implemented in many formats, but it just means that ffmpeg / whatever only has a specific option for it
[12:31] <burek> dango, why do you not like joint stereo?
[12:32] <JEEB> not to mention that joint stereo can mean a lot in the ways of implementation >_>
[12:32] <dango> burek no idea
[12:32] <burek> dango, did you read that url above I left for you?
[12:32] <dango> i never seen joint stereo in AAC or vorbis  wma
[12:32] <dango> yes i did
[12:33] <JEEB> http://en.wikipedia.org/wiki/Joint_%28audio_engineering%29#Joint_stereo
[12:33] <JEEB> "Two forms are described here, both of which are implemented in various ways with different codecs, such as MP3, AAC and Ogg Vorbis."
[12:33] <burek> so, why are you asking such questions then?
[12:33] <JEEB> just that there are no options for it in the stuff you see doesn't mean the coding techniques aren't used elsewhere
[12:34] <JEEB> but I'd guess that most encoders use these techniques automatically as they become more needed
[12:34] <JEEB> and/or from the beginning depending on the format/encoder -- if it gives a perceivable compression benefit while not affecting audio quality
[12:34] <dango> what is better  aac-lc  or aac-he
[12:35] <burek> wav is the best
[12:35] <JEEB> The latter uses compression techniques that are good for low bitrates, but you can end up with a worse off end result if you use more bitrate than where it is needed
[12:36] <burek> JEEB, why would you spend more money than you actually need to? :)
[12:36] <JEEB> which is why most encoders that can do both set the mode depending on the bitrate you're encoding with
[12:37] <JEEB> burek, as far as I've heard the HE-AAC stuff specifically kills some information that would otherwise be left around. Not to mention that I usually encode with 128-192kbps regions anyway
[12:37] <dango> why is there version 2 of aac-he
[12:37] <JEEB> I don't need the extra compression
[12:37] <JEEB> if you can give me a compression algorithm that isn't limited to lower bitrate scenarios because of the herp derp it does to the stream, I'm fine with that
[12:37] <burek> dango, read the wikipedia about AAC, they even have a picture for you, regarding that question
[12:38] <JEEB> HE-AAC, though, seems to be exactly for low bitrate things and isn't meant for relatively accurate compression
[12:38] <dango> and what about AAC-LTP?   why does so many players have problem with this
[12:38] <JEEB> which is also the reason why encoders only stick their HE-AAC modes on with lower (<=64kbps or so) bitrates
[12:38] <burek> aac+ is just like mp3, made for best quality with as low bitrates as possible
[12:39] <dango> i don't even see aac-LTP in wiki
[12:40] <JEEB> burek, tl;dr if HE-AAC is always better than LC-AAC, why do encoders switch their algorithms depending on the scenario :)
[12:40] <burek> dango
[12:40] <JEEB> that's the only thing that icks me in the whole LC/HE-AAC thing
[12:41] <burek> JEEB, because they are not updated ^^
[12:42] <JEEB> sigh...
[12:42] <burek> I mean, if your goal is quality, regardless of the size (bitrate), you wont use AAC in the first place, you'll use flac, right?
[12:42] <JEEB> no
[12:43] <JEEB> I'd use wavpack for lossless as it has specified channel mappings
[12:43] <JEEB> but that's the "lossless" area
[12:43] <JEEB> which is usually 800kbps+
[12:43] <JEEB> I'm not comfortable with using 800kbps+ on audio, and thus we enter the roughly 128-256kbps zone.
[12:44] <burek> so, you do care about size/bitrate?
[12:44] <dango> is wavpack even playable?
[12:45] <JEEB> of course, libavcodec's decoder was fixed by uau and friends
[12:45] <JEEB> I care about size but I don't care to use algorithms that specifically lower the quality of audio -- like HE-AAC does. Not to mention that my comfort zone is over the rates where HE-AAC is useful
[12:45] <dango> isn't monkeyaudio or flac better than wavpack
[12:46] <JEEB> compression-wise monkey's audio is better than wavpack IIRC, but FLAC is worse off. Also, monkey's audio is a mess in many ways which is why it's not on the selection list to begin with.
[12:46] <burek> well, as I said before, I tested aac+ on classical music and the sound was perfect, so I don't see that part of "lower the quality of audio"
[12:46] <dango> why you say it's a mess
[12:46] <burek> and classical music has really wide range/spectar of freq to encode
[12:46] <JEEB> dango, non-open format that is not spec'd
[12:46] <dango> jeeb who cares if it's not open or not
[12:47] <JEEB> because, you know, you want to know if the decoders etc. are doing it right?
[12:47] <dango> and what does not-open have to do with being a mess
[12:47] <JEEB> because the spec is not open
[12:47] <dango> jeeb what about ac3/dts
[12:47] <JEEB> and lacks info, it is a mess -- let's just begin with channel mappings for example
[12:47] <burek> use 7zip on a wav file and that's it ^^
[12:47] <JEEB> AC3 and DTS are both old
[12:48] <dango> jeeb are ac3/dts open?
[12:48] <JEEB> I don't think so, but the specs at least exist and open source developers to a level have acquired them
[12:48] <JEEB> not to mention that stuff like audio channel mappings have been specified
[12:49] <JEEB> thus, albeit f.ex. DTS is complete shit compression-wise
[12:49] <JEEB> it is still less of a mess than monkey's audio
[12:49] <JEEB> both are terrible formats in different classes
[12:49] <dango> why if flac more popular than wavpack then
[12:50] <dango> is
[12:50] <JEEB> it's a viable alternative, and the difference between wavpack and it are small
[12:50] <dango> and is wavpack open?
[12:50] <JEEB> yes, it is
[12:51] <JEEB> the problems only come up with around 5.1 and over, where the channel mappings aren't specified at FLAC, so for most music it's just fine
[12:51] <dango> jeeb best lossless compression is actually this one:   http://www.lossless-audio.com/comparison.htm
[12:52] <JEEB> sure, there are lossless compression formats that compress better than flac/wavpack
[12:52] <JEEB> I'm just not sure I want to use them :D
[12:52] <JEEB> you can just check out the 'enctime' and 'dectime' areas
[12:53] <JEEB> there are spots that are way over my comfort level :)
[12:53] <dango> jeeb true
[13:00] <burek> there is always spide-quality-size triangle of restrictions
[13:01] <burek> you can influence at most the two of them at anytime
[13:01] <burek> the third will simply be the result of your choice for those two
[13:11] <burek> spide :)))))))) speed* :)
[14:30] <brontosaurusrex> any decent assumptions about the multithreading status of prores decoder/encoder ?
[15:03] <cbsrobot> brontosaurusrex: patch welcome :)
[15:40] <coony> hi
[15:41] <coony> it possibol to convert un file .mov on other format having the same quality
[15:42] <JEEB> -acodec -vcodec copy
[15:42] <JEEB> :P
[15:43] <coony> ok
[15:43] <coony> but it's important have a svn ffmpeg?
[16:05] <cbsrobot> coony: ... git ffmpeg
[16:27] <symtab> hi
[16:27] <symtab> what get i use to get the same results as -vpre baseline
[16:27] <symtab> http://pastebin.com/QxW7Pthe
[16:27] <symtab> ?
[16:28] <symtab> i need to get this output:
[16:28] <symtab> http://pastebin.com/jRTBQwWB
[16:28] <symtab> Constrained Baseline level 1.3
[16:45] <burek> symtab, use -x264opts
[16:49] <burek> also, read this: http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Profiles
[17:06] <coony> how can add different file .mov?
[17:20] <burek> coony?
[17:21] <coony> so, i have a more single file.mov and i want unity on one file.avi
[17:35] <burek> can you use google translate?
[19:55] <zorbi> I have a question about streaming live transcoded content in mp4 format to an iPad.
[19:56] <zorbi> I am trying to transcode an MPEG2 file into MPEG4 directly to stdout and send it through a web server into my waiting ipad
[19:56] <zorbi> alas, mp4 is reporting not to support non-seekable formats (as can be seen in the implementation of movenc.c)
[19:56] <zorbi> Apparently from the need to update the MOOV atom.
[19:57] <zorbi> Does that mean one cannot produce live streaming (for content not pre-generated previously into a file)?
[19:57] <zorbi> For an mpeg4 container format, that is.
[20:59] <funyun> hi. is it possible to convert a mkv with DTS to AC3 with 5.1 surround sound at 640kbps with ffmpeg while keeping the video untouched?
[21:01] <hi117> ffmpeg -i file.mkv -vcodec copy -acodec ac3 out.mkv < does this work?
[21:02] <funyun> hi117: thanks. i'll try
[21:06] <burek> zorbi you cant stream live video to iPad
[21:06] <burek> buy a normal device :)
[21:07] <burek> funyun, also please copy/paste your command + output to pastebin.com
[21:07] <burek> so we can see what the media looks like
[21:11] <JEEB> burek, uhh what
[21:11] <JEEB> didn't ipad support mpeg-ts over http just fine?
[21:11] <JEEB> which can be streamed in a few ways
[21:12] <funyun> burek: http://pastebin.com/SSR42bgF
[21:14] <burek> JEEB, i think not
[21:15] <burek> if that was the case, people wouldn't bother with "progressive http streaming"
[21:15] <burek> and stuff
[21:15] <JEEB> burek, note: it does
[21:16] <JEEB> progressive http streaming is just easier to set up :P
[21:16] <JEEB> as you don't need something to be encoding it in real time
[21:16] <JEEB> :P
[21:16] <JEEB> http://en.wikipedia.org/wiki/HTTP_Live_Streaming
[21:16] <burek> ok then
[21:16] <burek> i was wrong :)
[21:16] <burek> i don't use that crap anyway :)
[21:16] <funyun> burek: i get that error when i try
[21:17] <JEEB> burek, it's the easiest way of streaming to mobile devices to set up :P And is supported by both iOS and Android now, so herp derp. Would you rather have it, or some herpy derpy to set up rtsp stream?
[21:17] <JEEB> :P
[21:18] <hi117> id rather setup and manually code a way to UDP stream over the cell network
[21:18] <burek> funyun, add -sn
[21:18] <JEEB> suit yourself
[21:19] <burek> or -scodec copy
[21:19] <JEEB> I know http isn't the best way
[21:19] <JEEB> but herp derp
[21:19] <JEEB> you can relatively easily use VLC to do that thing
[21:20] <burek> ok, i believe you :)
[21:48] <funyun> burek: worked. thanks
[22:20] <tiim> can anyone suggest a channel for general 'problems with video data' questions?
[22:30] <burek> tiim, what kind of questions do you have in mind
[00:00] --- Sun Dec  4 2011


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