[Ffmpeg-devel-irc] ffmpeg.log.20120715

[burek]

[08:59] <emtz> hello
[09:47] <aro> are there any config settings for converting to mp4 faster? its slow as molasses for me
[09:55] <ubitux> depends on the codec; you might be able to just remux
[09:55] <ubitux> (-c copy)
[10:08] <WannaBeGeekster> Are you using threads?  Adding more threads can do the trick too obviously.
[10:28] <aro> i dont know if we are using threads or not
[10:28] <aro> its on a VM, but it has a fair amount of CPU/ram
[10:29] <aro> remux it? how long does that take? does it compress the file too? we mainly want to take advantage of the filesize/seeking over FLV
[10:30] <WannaBeGeekster> well threads is a switch, but ffmpeg needs to be compiled with thread support as well.
[10:30] <aro> is there a way to find out if it is compiled with it?
[10:31] <WannaBeGeekster> Do you have access to the command line?  Just try and put the -threads 2 on the end of any command and see what happens.
[10:31] <aro> --enable-pthreads
[10:31] <aro> ii assume that means it is?
[10:31] <WannaBeGeekster> Yes
[10:31] <aro> sweet
[10:31] <WannaBeGeekster> Yes, that can be very helpful
[10:32] <WannaBeGeekster> Speeds my conversions up significantly.  But if you are on a VPS what else is going on with the machine?  Becareful not to cause problems with other files.
[10:32] <WannaBeGeekster> other applications
[10:32] <aro> we should be okay... we have a fair amount of room to grow
[10:33] <aro> its more a VM than a vps
[10:33] <WannaBeGeekster> awesome...  Just keep in mind it keeps those threads tied up as long as it is converting video.  Ok cool.  That works.
[10:35] <aro> ok
[10:36] <aro> doing this command was really fast, and only increased filesize by like... 18kb (24,654kb file)
[10:36] <WannaBeGeekster> very nice
[10:36] <aro> ffmpeg -i IMG_0730.MOV -vcodec copy out.mp4
[10:37] <aro> is that a remux?
[10:37] <WannaBeGeekster> I am not sure about that one.  But that seems to be close if not.
[10:38] <aro> ok
[10:38] <ubitux> yes it is
[10:38] <WannaBeGeekster> cool
[10:38] <aro> it almost seems as though it shouldnt work that fast :)
[10:38] <ubitux> you don't reencode anything, just switch formats
[10:38] <aro> oh ok
[10:38] <WannaBeGeekster> Well just think of how long it takes to copy a file basically.
[10:38] <ubitux> but both formats must support the same codecs
[10:39] <WannaBeGeekster> Right, so it is just copying the video and audio that is already encoded to a new container.
[10:39] <aro> got it
[10:40] <aro> is 29.97fps relatively standard? or is it more for mp4 files?
[10:42] <WannaBeGeekster> Honestly not sure about that either.  I know that is a progressive scan frame rate.  But I don't know how it relates to containers.  How much action does the video have?  If it doesn't have much going on, you could probably reduce the frame rate wihtout too many problems.
[10:42] <aro> well.. its variable, its for people uploading videos that are to be reencoded
[10:42] <aro> so it could be any number of types of videos
[10:42] <aro> so i need to find a happy medium
[10:43] <WannaBeGeekster> yes, that is tough.  I would probably stick with 29.93 then.
[10:43] <WannaBeGeekster> or 97
[10:43] <aro> ok
[10:43] <WannaBeGeekster> Although 25 might work, it is hard for me to tell.  I am still pretty new at video stuff myself.
[10:44] <aro> okay
[10:45] <WannaBeGeekster> ubitux will probably be able to tell you
[10:45] Action: aro waits with bated breath
[10:45] <ubitux> why do you care about this?
[10:46] <WannaBeGeekster> Does FPS affect the file size at all?
[10:46] <aro> because we want to find a happy balance between quality and filesize while being able to seek streamed content properly
[10:46] <ubitux> 24 is fine
[10:47] <ubitux> well, don't believe me, just try :)
[10:47] <aro> however, i get an error when i try to perform the same operation on an avi file
[10:48] <aro> [mp4 @ 0x135e0060] Tag [1][0][0][0]/0x00000001 incompatible with output codec id '46' ([0][0][0][0])
[10:48] <WannaBeGeekster> Yes, I think that you will need to write a script that parse's the output from ffmpeg -i filename to determine the correct command line to run.
[10:49] <aro> there isnt a catch-all type command i can run?
[10:50] <WannaBeGeekster> Honsetly, not that I am aware of.  The issue is when you are just copying the audio and video out, it means that you will have to know if the video is compatible with the current format.  Otherewise you can't just copy it, you will have to reencode it.
[10:50] <aro> re-encoding it is fine
[10:51] <WannaBeGeekster> So taking a MOV to a MP4 is probably fine (for the most part), a AVI file is a shot in the dark.  No telling if it will work or not.
[10:51] <aro> can you re-encode/copy-remux in the same command? or no
[10:51] <WannaBeGeekster> Not without using some kind of error handling in your script you are using to process the file.
[10:51] <aro> got it
[10:52] <WannaBeGeekster> But, that would probably be pretty easy to do instead of trying to process the output from ffmpeg -i.
[10:52] <aro> right
[10:52] <WannaBeGeekster> There might be other programs you could use that would be easier to process the output from, but I don't know what they would be.
[10:53] <aro> ya
[10:53] <WannaBeGeekster> Have you seen Kaltura before?  Not sure if it would somehow work out for you, but still.  It is pretty cool.
[10:53] <aro> i havent seen that
[10:54] <WannaBeGeekster> I briefly looked at it about 1.5 years ago and was pretty awestruck with it.  I have slept since then so I don't remember what my plans were for it.  I am not working for the same copmany any more, so the need disappeared with the job.
[10:55] <aro> ill have to check that out
[10:55] <WannaBeGeekster> It might have some code in there that could be useful to you in the very least.  As far as video processing goes at least.
[10:55] <aro> its not free!
[10:56] <WannaBeGeekster> They do have an open source version, but you have to dig for it.
[10:56] <WannaBeGeekster> Try under community
[10:56] <aro> oh cool
[10:56] <WannaBeGeekster> www.kaltura.org is the os version
[10:57] <aro> ya the community edition?
[10:57] <WannaBeGeekster> yup
[10:57] <aro> awesome
[10:58] <WannaBeGeekster> Do you guys have a live site yet or are you still in development right now?
[10:58] <aro> technically still in development.. pending bank approval
[10:59] <aro> like, the site is done, and right now our video encoding is using flv - i just want something a bit more robust
[11:00] <WannaBeGeekster> sweet.  That works.
[11:00] <WannaBeGeekster> If you go live and see me around send me a link.
[11:00] <aro> unforutnately its not great for seeking
[11:00] <aro> sure thing! ill add you to my notify list
[11:00] <WannaBeGeekster> That is unfortunately true
[11:01] <WannaBeGeekster> just pm'd you my email if that helps
[11:17] <ma11s> Any plans to support zero byte packets in MPEG TS streams to achieve true CBR?
[14:55] <rascal999> hello i am trying to record my desktop and use webcam as mic input. This is what i have so far, which records the desktop but not sound.    ffmpeg -y -f alsa -ac 2 -i "plughw:CARD=camera,DEV=0" -f x11grab -r 30 -s 1920x1080 -i :0.0 -acodec pcm_s16le output.wav -an -vcodec libx264 -preset ultrafast -crf 0 output.mp4
[14:57] <burek> rascal999, take a look at tutorials
[15:01] <rascal999> burek: arecord -L doesn't appear to show webcam audio input
[15:03] <burek> then it doesn't have one
[15:05] <rascal999> burek: it does, recordMyDesktop works and "arecord -l" outputs capture device mapping to "hw:2,0"
[15:05] <rascal999> but if i specify   ffmpeg -y -f alsa -i "hw:2,0" -f x11grab -r 30 -s 1920x1080 -i :0.0 -acodec pcm_s16le output.wav -an -vcodec libx264 -preset ultrafast -crf 0 output.mp4
[15:05] <rascal999> i get [alsa @ 0x10d5140] cannot set channel count to 2 (Invalid argument)
[15:05] <burek> rascal999, then your alsa is not installed properly
[15:05] <burek> both arecord -l and arecord -L should give same results
[15:05] <burek> same number of capture cards
[15:05] <burek> if not, reinstall alsa
[15:06] <rascal999> burek: how do i know if a device is capture device using -L ?
[15:06] <rascal999> burek: shouldn't say input or capture somewhere?
[15:06] <burek> arecord lists only capture devices
[15:07] <rascal999> burek: but in the descriptions i see stuff like "7.1 Surround output to Front, Center, Side, Rear and Woofer speakers"
[15:07] <rascal999> arecord -L
[15:08] <burek> find something that starts with "default"
[15:09] <rascal999> Default ALSA Output (currently PulseAudio Sound Server),   HDA Intel, STAC92xx Analog,   sysdefault:CARD=camera
[15:11] <truexfan81> will that compile guide in the topic have the link where i can do a git pull of ffmpeg mt?
[15:17] <burek> rascal999, can you use pastebin to show the output of arecord -L
[15:18] <burek> truexfan81, ?
[15:18] <burek> why don't you read it and see for yourself?
[15:19] <rascal999> burek: i got it working with    ffmpeg -y -f alsa -ac 1 -ar 16000 -i hw:2,0 -f x11grab -r 30 -s 1920x1080 -i :0.0 -acodec pcm_s16le output.wav -an -vcodec libx264 -preset ultrafast -crf 0 output.mp4
[15:20] <rascal999> burek: but now i get a crackle noise from webcam, can't remember how i fixed this in audacity
[15:20] <burek> well
[15:20] <burek> your cpu is slow
[15:20] <burek> or your graphic card
[15:20] <burek> you are grabbing at full hd at 30 fps
[15:21] <burek> try lowering fps to -r 25
[15:21] <burek> or -r 15
[15:21] <rascal999> burek: i don't think it's that, because it sounds bad in audacity as well
[15:22] <rascal999> burek: thought i fixed it
[15:23] <burek> it is
[15:24] <burek> because ffmpeg cannot do it fast enough
[15:24] <burek> and you get crackles
[15:24] <rascal999> burek: but if i'm just using audacity i'm not recording the desktop
[15:24] <burek> using audacity for what?
[15:25] <burek> you mean you tried to record the sound using audacity also?
[15:25] <rascal999> burek: no i'm just testing in audacity atm
[15:25] <rascal999> burek: to try and fix crackle
[15:25] <burek> man
[15:25] <burek> dont fix crackles
[15:25] <burek> do like i told you to avoid having crackles in the first place
[15:25] <rascal999> burek: how?
[15:26] <burek> lower your cpu usage
[15:26] <burek> lower the -s or -r
[15:26] <burek> try 320x240 instead
[15:26] <burek> just for a test
[15:26] <rascal999> burek: ok
[15:26] <rascal999> DTS 3461138, next:3470000 st:0 invalid dropping
[15:26] <rascal999> PTS 3461138, next:3470000 invalid dropping st:0
[15:26] <rascal999> burek: that spams
[15:27] <rascal999> burek: running with ffmpeg -y -f alsa -ac 1 -ar 16000 -i hw:2,0 -f x11grab -r 30 -s 20x80 -i :0.0 -acodec pcm_s16le output.wav -an -vcodec libx264 -preset ultrafast -crf 0 output.mp4
[15:27] <rascal999> burek: it's not cpu or gfx, i have i7 with 1gb nvidia card
[15:27] <burek> pastebin..
[22:19] <tdj-br> Hi, i would like to stream audio only using RTP
[22:20] <tdj-br> ffmpeg -formats give me RTP
[22:20] <tdj-br> but this command is failing:
[22:20] <tdj-br> ffmpeg -i c:\temp2\bla\sing.mp3 rtp://127.0.0.1:54546
[22:20] <tdj-br> any help is appreciated
[22:21] <tdj-br> -f rtp
[22:22] <tdj-br> i would like to ignore video from input... any tip?
[22:26] <brocatz> have any of you worked with UVC?  i have a logitech quickcam with a h264 chip on it, i want to tell it to fire me teh video in h264, if i use directshow it seems to just give me a standard format, like MJPG or RGB24
[22:28] <arpu> tdj-br,  try  -c:a copy
[22:29] <arpu> and -vn
[22:57] <Slackyman> hi
[22:58] <Slackyman> I'm trying to build a huge static ffmpeg linked to static libs but it keep compiling with some dynamic system-wide libs
[22:59] <Slackyman> I put my static libs to a directory
[22:59] <Slackyman> and give the right CFLAGS and LDFLAGS to the compiler
[22:59] <Slackyman> most of them are used the right way
[23:00] <Slackyman> but it keeps using libSLD, libgnutls, libgpg-error as dynamics
[23:01] <Slackyman> *libSDL
[23:02] <Slackyman> ok, I found right now that I missed compiling SDL static (so it uses system SDL that is dynamic)
[23:03] <Slackyman> but WHY it keep using system GNUTLS  libs instead the one i compiled?
[23:03] <Slackyman> anyone can help me?
[23:44] <philipl> Hi all. To effectively handle styles for the timed text subtitles, I'm really going to need something like avio that I can use from avcodec. Moving avio in avutil seems messy, given the dependencies on other parts of avformat, especially the url stuff.
[23:44] <philipl> Is there something else I can use?
[00:00] --- Mon Jul 16 2012