[Ffmpeg-devel-irc] ffmpeg.log.20120422

[burek]

[00:00] <krobins> i have it working. i converted yuv420p to gray pixel format, but i'm looking for a little more information
[00:01] <krobins> i was wondering why the video size only went from 22MB to 15MB when the pixel information went from 3x12 to 1x8
[00:02] <krobins> i would have expected the size of the video to drop by about 75%
[00:03] <krobins> also, i was curious if anyone has any experience in getting the video into 4bit grayscale
[00:03] <krobins> none of the pix_fmts listed seemed to have that, but it seems like it would be easily doable
[00:37] <burek> elkng, hi "scientist" :) would you be so kind to offer a better text for the manual, regarding the section about -map option? :)
[00:38] <burek> how difficult it is to just type -map <i want this stream> -map <i want that stream too>
[05:39] <brad0> Being a bit of a git n00b can anyone assist me in trying to pull down what looks like a branch but I don't think it is? I'm trying to get the 0.7 branch.
[05:44] <Olson> im wondering how I would grab system sounds via x11grab on a, shall we say standard linux system with ALSA.  . if   -i hw:1,0   is my mic, then is there something also I could put there to grab those sounds, say if I was playing back some video or so and I wanted that audio to be in the capture also?
[05:46] <Olson> I hope it's not too much to ask but also.. It appears I could use multiple inputs with -i  .. ie at the moment we have video and microphone so adding another that accepts system sounds could be done at the same time perhaps
[05:48] <Olson> as I side note.. I have tried to use JACK.. for the life of me I find it confusing.. if that is the solution then.. ok i'll have to crack on with it
[06:09] <Olson> it's not clear to me how to x11grab and take the mixer output in there.. mic is ok, though I not sure how to get sound from video playing on the system or so
[07:13] <yjacket> I am trying to convert an MKV file to an MP4 file, but ffmpeg fails... details here: http://pastebin.com/qBK9e92y
[07:16] <yjacket> **convert MKV to MP4, using the same audio and video tracks
[07:16] <yjacket> I was trying the instructions here: http://forum.doom9.org/archive/index.php/t-124877.html
[07:41] <briggers_>  http://pastebin.com/qBK9e92y
[07:41] <briggers_> bugger, sorry about that.
[08:02] <yjacket> briggers_ any idea why it won't work?
[08:12] <briggers_> Nope, sorry. Maybe you could upload a sample of the input file.
[08:32] <briggers_> yjacket: try, ffmpeg -i old_video.mkv -sameq new_video.mp4
[10:53] <jondot> is there a way to use gstreamer to output a series (20-30) of video thumbnails from a given video, in even spacing?
[10:54] <jondot> oops. ffmpeg, im trying both :)
[11:03] <briggers_> jondot: You mean an animated gif?
[11:04] <jondot> briggers_, either that or a series of images. just like what youtube now does (and the less politically-correct youporn)
[11:05] <jondot> i can do a single frame with ffmpegthumbnailer, so i can make a loop that takes X frames and calls it each time
[11:05] <jondot> since i'll be doing it on the serverside i wouldn't like to have to do that
[11:06] <jondot> i'd prefer that to happen entirely inside ffmpeg or other binary
[11:06] <briggers_> Maybe you can use the -t switch and the -ss switch
[11:08] <jondot> -t is duration but -ss is?
[11:08] <briggers_> ffmpeg -i $INPUT_VID -ss $STARTTIME -t $DURATION $OUTFILE.GIF
[11:08] <jondot> but this is a single frame right?
[11:08] <briggers_> -ss is the start time offset
[11:09] <briggers_> You should get a gif that starts at $STARTTIME of the video and contains $DURATION lenght of the video.
[11:10] <jondot> ah i see. well i wasn't intending to do that.. i was intending to make a gif or a series of images, in constant intervals in the movie
[11:10] <jondot> so for example, snap a frame every 1 minute for a 60minute movie, makes a 60second preview of it
[11:11] <briggers_> oh, okay.
[11:12] <briggers_> If you can read php, this migh help http://www.alberton.info/video_preview_as_animated_gif_with_ffmpeg_and_spl.html
[11:13] <jondot> briggers_, yep this is what i'm defaulting to do. however it involves N shell calls per video
[11:15] <briggers_> Well, I dont see anything in the command line options that suggests you can do it in only one call.
[11:15] <jondot> thanks.. i'll try and see if there's a way to write the glue code in C
[11:17] <briggers_> well, for an N frame gif, you'll need to do only about N+1 calls, maybe that isnt too bad.
[11:22] <jondot> yes. i'm kind looking at sources, like this https://github.com/lajos/iFrameExtractor/blob/master/Classes/VideoFrameExtractor.m
[11:22] <jondot> looks like if I wanted to do such a thing, there are quite a few new things I need to be familiar with from the video/ffmpeg domain
[11:23] <jondot> now i'm wondering - in terms of codecs, does ffmpeg cover all or most codecs? is there a list somewhere?
[11:24] <briggers_> Try the -r switch. I think that's the one you want if you want even spacing.
[11:25] <jondot> ah. thats an interesting take actually
[11:25] <jondot> reduce the frame rate..
[11:25] <briggers_> I dont have access to ffmpeg right now, but the man page says the -r accepts fractional values.
[11:25] <jondot> so if i go with 1/60 im looking at what i want
[11:26] <briggers_> Not sure, i suppose you'll need to do a bit of trial and error.
[11:26] <jondot> yup, thanks thats a good start
[11:27] <briggers_> also see, http://ffmpeg.org/general.html for supported formats
[12:35] <jondot> briggers_, fyi, here is the command im using: ffmpeg -i sample_iPod.m4v -r 0.2 -sameq -f image2 thumbs%02d.jpg
[12:35] <jondot> works nicely
[13:14] <Olson> it's not clear to me how to x11grab and take the mixer output in there.. mic is ok, though I not sure how to get sound from video playing on the system or so
[13:15] <Olson> as I side note.. I have tried to use JACK.. for the life of me I find it confusing.. if that is the solution then.. ok i'll have to crack on with it
[13:30] <Olson> mmm..
[14:14] <qarpfen> is there a difference in using "-c:a vorbis" and "-c:a libvorbis"?
[14:18] <sacarasc> Yes.
[14:23] <qarpfen> sacarasc: can you tell me about them? And do you know good options to convert DVD VOBs to libxvid?
[14:24] <qarpfen> sacarasc: (except that vorbis also supports decoding and direct rendering method 1)
[14:25] <sacarasc> vorbis is the internal ffmpeg one, libvorbis is the library libvorbis.
[14:27] <qarpfen> sacarasc: so the code in vorbis is not written by xiph but by ffmpeg devs?
[14:29] <sacarasc> Yes.
[14:29] <sacarasc> I think.
[14:30] <qarpfen> does anyone have good options to convert DVD VOBs to xvid?
[14:32] <Olson> :(
[15:02] <qarpfen> how do I set frame rate to same as source?
[15:02] <qarpfen> (Why, at all, defaults frame rate to 25 and not to same as source?)
[15:06] <JEEB> umm, so far as long as the source had some notion of a frame rate or time stamps it has used the source frame rate for me by default?
[15:07] <JEEB> (or more correctly "source time stamps" as most formats have time stamps instead of a single "frame rate")
[15:07] <Olson> how do I make x11grab record also system sounds from playing video or so?  do I need JACK?  linux.
[15:59] <qarpfen> what is the grouping (-g) good for? Should I use it when converting to xvid?
[17:05] <taqattack> Is there a way to capture sound output in windows without Stereo Mix?
[17:17] <qarpfen> is it rather advisable to use vorbis or libvorbis?
[18:15] <ZodiacMentor> Converting three PNGs with alpha to huffyuv with this: http://pastebin.com/MuVq09B4 and then trying to read that and write them back to png's with this code: http://pastebin.com/Dd80Jix0 avcodec_decode_video2() returns 0 in the got_picture_ptr. the code works with other avi's, like xvid. Any help appreciated!
[18:26] <Olson> I make screencasts using ffmpeg and x11grab, I was wondering if whilst recording the mic I could also add something on the commandline to capture system sounds, be it some audio track or video or whatever. Using linux with ALSA
[18:48] <iive> Olson: i remember when the sound cards used to have a lookback capture stream. I guess thank's to MAFIAA this functionality have been slowly phased out.
[18:49] <iive> no idea if alsa or pulse support that kind of functionality.
[18:51] <Olson> it'll be possible using JACK
[18:51] <Olson> but that thing confuses the heck out of me
[18:52] <Olson> i was hoping for a   -i hw:mixer   or so :P
[18:55] <ZodiacMentor> I managed to get some frames out, by looping avcodec_decode_video2() until it returns 0, but for some odd reason the frames are all the same frames...
[19:07] <iive> ZodiacMentor: try to disable threaded decoding and see if you get the same result.
[19:08] <iive> in that case it shuold not delay more than 2 frames.
[19:08] <iive> 2 in case of h264 with b-pyramid, and 1 in case of b-frames.
[19:10] <ZodiacMentor> how I do disable threaded decoding from within the code? and the codec used is huffyuv with pxfmt bgra, ffplay play's the file perfectly
[19:28] <ZodiacMentor> I got it fixed by doing the avcodec_decode_video2() loop like in ffmpeg.c
[19:28] <ZodiacMentor> putting that inside the loop {pkt.data += pkt.size; pkt.size -= pkt.size;
[19:28] <ZodiacMentor> }
[19:28] <ZodiacMentor> now it works as it should
[19:30] <Rik316> When should , if ever, CONFIG_MEMALIGN_HACK be defined?
[20:07] <iive> Rik316: when the OS doesn't have native memalign()
[20:26] <elkng> the latest git of ffmpeg is unstable ?
[20:28] <sacarasc> It's probably pretty stable.
[22:27] <mystica555> i seem to be having issues making the yadif filter engage properly..
[22:28] <mystica555> hm well thats interesting; it wasnt working before..
[22:29] <mystica555> ah. its how im trying to instantiate it.
[22:29] <mystica555> -filter:v yadif ; does not seem to work.
[22:29] <mystica555> -vf yadif ; does
[22:30] <mystica555> is there something inherently different about those ?
[22:31] <mystica555> (enable, if not instantiate...damn english)
[22:38] <vbgunz> I ran this about 3 hours ago "ffmpeg -i /x.mkv -vcodec libx264 -acodec ac3 -ab 448k -ss 00:00:00 -t 01:00:00 ~/y.1.mp4" ... on a 9GB mkv movie. It's still going and I have no idea when it's going to finish *but* I feel it won't be today. It might be a little exaggerated but damn, for the love of god or kittens, there has to be a faster way?
[22:40] <JEEB> first of all, do you get any asm optimizations used with x264? It should output a list
[22:40] <JEEB> SSE, SSE2(Slow), etc. etc.
[22:40] <vbgunz> JEEB: I can paste what I see so far, I'll do it to a pastebin, one moment
[22:41] <JEEB> I'm just starting out with the check if your x264/ffmpeg compiles seem sane'ish :P
[22:42] <vbgunz> hmm, trying to copy what I see but it seems to get reset most likely by the last line
[22:43] <mystica555> vbgunz: ctrl-s to pause terminal output
[22:43] <mystica555> then copy
[22:43] <mystica555> then ctrl-q to continue
[22:44] <vbgunz> this is what I see from calling ffmpeg with those options http://dpaste.com/735717/
[22:44] <vbgunz> mystica555: that's a gem. thanks
[22:44] <JEEB> ok
[22:44] <JEEB> using cpu capabilities: MMX2 SSE2Fast FastShuffle SSEMisalign LZCNT
[22:44] <JEEB> at least it's built with optimizations, so that part is fine
[22:44] <JEEB> a bit older revision of course, but that's not major
[22:44] <Mavrik> 200 kb/s?
[22:45] <vbgunz> hmm, mystica555, Ctrl-s didn't pause anything. I thought that was going to be awesome :)
[22:45] <Mavrik> I've found some very wierd behaviour when you force an encoder so low at such resolution.
[22:45] <JEEB> Mavrik, I wonder if it really is doing that
[22:45] Action: JEEB checks the libx264 line
[22:45] <mystica555> vbgunz: hm; that should have worked with most terminal implementations on *nix.
[22:45] <JEEB> rc=crf mbtree=1 crf=23.0
[22:45] <JEEB> yes, it is using libx264 defaults
[22:46] <JEEB> not 200kb/s
[22:46] <Mavrik> hmm
[22:46] <Mavrik> point there
[22:46] <vbgunz> thats the last line > frame=78025 fps=  7 q=28.0 size= 1374423kB time=00:54:12.49 bitrate=3461.7kbits/s
[22:46] <Mavrik> you're about done then ^^
[22:46] <Mavrik> vbgunz: what's your CPU?
[22:47] <JEEB> vbgunz, first of all, let me ask what you're doing?
[22:47] <JEEB> what is it that you're trying to do?
[22:47] <JEEB> I can see that you probably know that you want AC3 audio
[22:47] <vbgunz> JEEB: turning a 9GB mkv into 3 mp4 files for playback on a PS3
[22:47] <JEEB> ok
[22:47] <vbgunz> Mavrik: I have an AMD Quad 965
[22:47] <JEEB> depending on how the source you're using is encoded, you wouldn't need to re-encode
[22:47] <JEEB> you could just -vcodec copy
[22:48] <vbgunz> JEEB: yeah, I tried that, vcodec and acodec and what happens is, I get no audio on the PS3 and the video seems to be playing in slow motion
[22:49] <vbgunz> sorry, I meant I tried vcodec copy and acodec ac3
[22:50] <JEEB> try a newer ffmpeg (and update libx264 while you're at it)
[22:50] <JEEB> it should work, if the stream plays on the PS3 that's already good enough
[22:51] <vbgunz> I'm on Fedora 16 x264 using pretty much default repos and rpm-fusion
[22:51] <JEEB> it shouldn't be hard, do you have yasm and git?
[22:51] <vbgunz> Yeah, this should definitely run on the ps3, just shocking in a sense I've spent 3 hours so far
[22:52] <vbgunz> I have git, not sure what yasm is
[22:52] <JEEB> well, you were trying to re-encode the video stream :P
[22:53] <JEEB> that takes time
[22:54] <vbgunz> I just had no idea it would take so long, I expect for this to all be done in about another 6 hours. I'm happy after spending all night trying to figure this out to get something going but I just didn't know it would take so long to convert
[22:55] <JEEB> I have no idea what exactly currently is limiting you, but libx264 does have presets (-preset name-of-x264-preset) if you absolutely need to re-encode :V
[22:55] <JEEB> but if the damn stream plays with a PS3, I'd say that a copy of the stream would work fine
[22:55] <JEEB> and you'd just re-encode the audio
[22:55] <JEEB> http://mewiki.project357.com/wiki/X264_Settings#preset
[22:56] <vbgunz> I tried using -vpre ultrafast and a 5 minute slice of a test turned out to be something like 3GB. It should have been called ultracowsize or something :)
[22:56] <JEEB> well, d'uh
[22:57] <JEEB> the fastest and the slowest presets aren't recommended for general usage
[22:57] <JEEB> also I'm not sure if -vpre does the same as -preset
[22:57] <JEEB> (the main thing being that it should access libx264's presets, not the ffpreset files)
[22:57] <JEEB> basically ultrafast is for speed tests :P (to show that x264 can be fast)
[22:58] <vbgunz> -preset is a new option isn't it? because I read about this online but everytime I go to the manual, there is no -preset option
[22:58] <JEEB> and placebo is for compression testing
[22:58] <JEEB> possible
[22:58] <JEEB> it's what should be used now for setting presets
[22:58] <JEEB> as long as the option accesses libx264's internal presets, we're fine
[22:58] <JEEB> whatever the option is called
[22:59] <Mavrik> (it's -preset)
[22:59] <JEEB> yes, in current ffmpeg
[22:59] <JEEB> that comment was in relation to the fact that the guy's ffmpeg doesn't have it :P
[22:59] <JEEB> but yeah, I would first of all check out the current ffmpeg git HEAD
[22:59] <JEEB> and try vcodec copy + audio encoding
[22:59] <JEEB> and then fall back to re-encoding video with the slowest preset you can take if you need to re-encode it
[23:00] <vbgunz> I'll wait and hopefully the beefy miracle will include a much later version of ffmpeg
[23:00] <CoJaBo> o cool, theres a channel for it ..
[23:00] <CoJaBo> ..Is there anything that can trascode/cut/edit/anything a .rm file on linux? Already tried the obvious (avidemus wont decode the video, mencoder just freezes, and ffmpeg can't seem to produce an output file with audio less than 2 hours out of sync)
[23:00] <JEEB> if current git HEAD ffmpeg can't handle it, then you're out of luck for the time being :P
[23:01] <JEEB> (it's worth it to make a trac issue about it with a sample if it doesn't work with current git HEAD tho)
[23:02] <CoJaBo> hm. How do I get the very latest version then?
[23:02] <JEEB> git?
[23:02] <JEEB> http://git.videolan.org/?p=ffmpeg.git
[23:02] <JEEB> you'll probably need yasm, too
[23:03] <JEEB> but that should be it
[23:03] <CoJaBo> gah, i hate compiling stuff :/
[23:03] <JEEB> I'm sorry, but multimedia stuff usually goes forward so quickly that you can't rely on distros :P
[23:05] <JEEB> and if I could compile ffmpeg, so can you. You can just set --prefix= to ${HOME}/ownapps or something
[23:05] <JEEB> or heck, you don't even have to install ffmpeg to try it out after compilation
[23:05] <mystica555> hrm got a slightly non-ffmpeg question but it'd ease my use of ffmpeg: anyone know a decent dvd ripping program that is GOP Exact (mplayer -dumpstream is leaving a B-frame with no second reference...) and allows for chapter extraction?
[23:06] <mystica555> trying to segment up individual videos for Two Mix: White Reflection The Movie ...
[00:00] --- Mon Apr 23 2012