[Ffmpeg-devel-irc] ffmpeg.log.20130414

Mon Apr 15 02:05:01 CEST 2013

[01:38] <fatpony> is it possible to apply a filter between specific frames? i want to run yadif on one section of a clip but not on the rest to avoid quality loss
[01:41] <fatpony> maybe using vf select?
[02:59] <elkng> if I use two pass encoding ffmpeg first generates some log file with this kind of content http://sprunge.us/WdBI, that means it scan for every frame and decides what will be bitrate for every frame instead of one global bitrate ? so when I create that video how it can later say what bitrate of that video is if it was generated per frame basis ?
[03:04] <hi117> elkng: in lossy audio when you do that it tries for an average bitrate
[03:04] <hi117> so if you want 100 bits per second, it might say 51 bits for this second and 150 for the next, the average is ~100
[03:06] <hi117> my completely uneducated guess at the internals of video encodes say that they do the same thing though
[03:06] <klaxa> depends on the codec in use though
[03:06] <hi117> encoders*
[03:07] <klaxa> for h264, according to the wiki at least, two-pass encoding is only really used if you want to match a certain filesize
[03:08] <klaxa> >Will two-pass provide a better quality than CRF?
[03:08] <klaxa> >No, though it does allow you to target a file size more accurately.
[03:08] <klaxa> taken from http://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide
[03:17] <elkng> I use "-c:v mpeg4" option for codec, but with two passes for same codec and same bitrate there is a huge difference, less noice and there are no visible "squares", but it takes about 3 times longer to encode
[03:17] <elkng> s/noice/noise
[03:19] <klaxa> sounds like it's what you want then, no? filesizes are similar i guess?
[05:33] <elkng> http://i.imgur.com/86FakDo.jpg
[06:24] <Trix> Hey there, using http://pastebin.com/6YhjhpCK I get huge amounts of blocking it seems, with any preset...
[06:24] <Trix> bad colors/etc~
[06:24] <Trix> I cant figure it out
[06:24] <Trix> tried a bunch
[06:28] <Trix> actually
[06:28] <Trix> i may be dumb
[06:28] <Trix> seems to be with 10bit files
[09:00] <dv--> ALSA buffer xrun...
[09:00] <dv--> facepalm
[09:24] <LithosLaptop> dv--: did you manage toget the colors working?
[09:24] <LithosLaptop> *to get
[09:25] <dv--> no, i gave up. it's not super important
[09:26] <LithosLaptop> I mentioned last time that you try yuvj444p instead of yuv444p
[09:26] <LithosLaptop> oh ok
[09:26] <dv--> i need to use yuv420p anyway because i'm ultimately uploading youtube
[09:26] <LithosLaptop> oh
[09:26] <dv--> to*
[09:26] <LithosLaptop> yeah, then there is nothing you can do
[09:26] <dv--> well, it's weird
[09:27] <dv--> i mean the color orange clearly exists in yuv420p
[09:27] <dv--> but the encoder is replacing it with grey in parts
[09:28] <LithosLaptop> weird
[10:02] <crackerjackz> i'm trying to make this .mp4 video smaller i found something on the net that says to run ... ffmpeg -i input.mp4 -acodec mp2 output.mp4   but i'm not exactly sure that's what i want? what does that do exactly, i ran it over an hour ago and its still encoding. its a 700 mb file, does it normally take that long?
[10:11] <zordiack> hi, could someone help me out with HLS streaming?
[10:11] <zordiack> i'm trying get a working ffserver.conf but having no luck with it
[10:15] <zordiack> http://pastebin.com/wR9pD0Gu
[10:15] <zordiack> here is the current config
[10:16] <zordiack> server starts and input stream is connected and feedind, but output is not working
[10:16] <zordiack> i get this in ffserver output
[10:16] <zordiack> Sun Apr 14 11:16:25 2013 Error writing output header
[10:16] <zordiack> Sun Apr 14 11:16:25 2013 94.237.88.69 - - [GET] "/studio.m3u8 HTTP/1.1" 200 79
[10:17] <zordiack> and client says invalid data when prosessing input
[10:18] <zordiack> anyone?
[10:24] <LithosLaptop> crackerjackz: you need to figure out what bitrate you need to use to get the target size you want
[10:25] <crackerjackz> LithosLaptop, how do i do that? isn't there like a gui i can use or something?
[10:26] <crackerjackz> what if i just convert it to .flv or something,, will that reduce the file size?
[10:26] <LithosLaptop> no, flv is just a container format like mp4 is
[10:27] <LithosLaptop> do a ffmpeg -i input.mp4
[10:28] <LithosLaptop> past the result and let me check the bitrate of the source
[10:29] <crackerjackz> LithosLaptop, http://pastebin.com/ahehZt5m
[10:30] <LithosLaptop> hmm thats not what I wanted :)
[10:31] <crackerjackz> LithosLaptop, today is the first time i ever used ffmpeg
[10:31] <zordiack> anyone with HLS streaming help?
[10:31] <crackerjackz> no idea how to use it... just found a command on a website  and hope it didn't kill my computer  :p
[10:32] <LithosLaptop> yeah, I just wanted the output from 'ffmpeg -i input.mp4'
[10:32] <LithosLaptop> without any output file specified
[10:32] <crackerjackz> LithosLaptop, okay give me a sec ill pb that info to you
[10:34] <crackerjackz> LithosLaptop, http://pastebin.com/setVRY4q
[10:35] <LithosLaptop> as you can see the average bitrate of the file is 13744 kb/s
[10:36] <LithosLaptop> you need to make that less to make a smaller file
[10:36] <LithosLaptop> example:
[10:37] <LithosLaptop> ffmpeg -i input.mp4 -c:v libx264 -b:v 9000k -c:a copy outfile.mp4
[10:38] <LithosLaptop> that would use a bitrate of 9000kbit/s for video and just copy the audio unaltered
[10:39] <LithosLaptop> to calculate the bitrate you want to use for a specific size: total size = (bitrate of video + bitrate of audio) * duration of video in seconds
[10:39] <LithosLaptop> I have to go afk
[10:39] <LithosLaptop> bbl
[10:45] <zordiack> please, i need to get iOS comptible stream out of ffserver
[11:07] <LithosLaptop> baseline maybe?
[11:07] <LithosLaptop> o it is
[11:07] <LithosLaptop> nm
[11:10] <zordiack> LithosLaptop: the pois is i need live streaming
[11:11] <zordiack> i couldn't get mp4 to work over http
[11:11] <zordiack> now i'm trying HLS but it's not working either
[11:12] <zordiack> i have webm and flv streams which work just fine
[11:12] <zordiack> but i need Apple support too
[11:15] <LithosLaptop> I am not 100% sure what resolutions,codecs and container formats ios supports over HTTP
[11:17] <zordiack> HLS container and MP4 encoding
[11:17] <zordiack> also MP4 with rtmp streaming i think
[11:17] <zordiack> but ffserver can't do rtmp serving
[11:23] <LithosLaptop> have you tried mpeg4 instead of libx264?
[11:28] <zordiack> i did, it gave me an error too
[11:28] <zordiack> i'll reproduce it
[11:29] <LithosLaptop> ah ok
[11:29] <zordiack> [mpeg4 @ 00000000059222e0] timebase 333333/10000000 not supported by MPEG 4 stan
[11:29] <zordiack> dard, the maximum admitted value for the timebase denominator is 65535
[11:29] <zordiack> Output #0, ffm, to 'http://piknik.wappuradio.fi:9001/feed2.ffm':
[11:30] <zordiack> i didn't understand that at all
[11:34] <LithosLaptop> yeah that is greek
[11:47] <zordiack> there is also and option -f hls present but no documentation on how to use it in encoding?
[12:00] <zordiack> anyone here with experience about HLS streaming?
[12:07] <elkng> why ffmpeg wasn't that way it is now like 5 years ago ?
[12:27] <fatpony> is it possible to apply a filter to a specific section of the video? i want to apply yadif to one section of a clip but not to the rest
[12:30] <LithosLaptop> hmm
[12:30] <LithosLaptop> no idea
[12:30] <fatpony> :/
[12:39] <zordiack> now i got hls stream to work but it stops after ~minute
[12:40] <LithosLaptop> wow, progress
[12:40] <elkng> section as on some frames or region as on some place in frame ?
[12:40] <zordiack> yeah but frustrating
[12:40] <zordiack> i'm using /tmd/feed1.ffm as an input
[12:41] <zordiack> frame= 2509 fps=313 q=34.0 q=34.0 size=N/A time=00:01:22.86 bitrate=N/A dup=11 dframe= 2570 fps=301 q=34.0 q=34.0 size=N/A time=00:01:24.90 bitrate=N/A dup=11 dframe= 2570 fps=284 q=34.0 q=34.0 size=N/A time=00:01:24.90 bitrate=N/A dup=11 d
[12:41] <zordiack> it just stops like that
[12:41] <zordiack> time is not progressing anymore and it stops producing segments
[12:41] <elkng> I heard people invented pastebin like sites long time ago, does anyone tryed to use them ?
[12:42] <LithosLaptop> usually for lots of text
[12:42] <zordiack> your irc buffer overflew?
[12:42] <LithosLaptop> 3 lines doesn't make sense
[12:42] <elkng> no but my patience can
[13:14] <LithosLaptop> does ffmpeg automatically apply dithering when for example converting from 24bit/96Khz tp 16bit/44.1Khz?
[13:14] <LithosLaptop> *to
[13:22] <xlinkz0> is it possible to change the metadata of a file 'in place' ?
[13:23] <xlinkz0> just add the metadata not use an output file.. this takes a lot of time because it copies the input file frame by frame
[13:24] <ubitux> xlinkz0: no you need to remux
[13:24] <ubitux> but -c copy should make things faster.
[13:24] <xlinkz0> but i just set metadata to the container not in the individual streams..
[13:26] <xlinkz0> but i lose the old metadata :(
[13:37] <xlinkz0> how do i set more than one metadata key=value pair in one call?
[13:38] <xlinkz0> ah nvm
[13:38] <xlinkz0> but is it possible to keep the old metadata?
[14:32] <zordiack> well if anyone is interested i think i nailed it at least somehow
[14:32] <zordiack> it's bit of a hack but it's working
[14:34] <zordiack> you create .ts stream output with ffserver and then use ffmpeg segmenter on that with -c:v copy and serve the files with some www-server
[14:53] <DylanCl> Hello. I'm using a script to stream to twitch.tv that uses FFMPEG. Is it possible to make my script do something like this: http://i.imgur.com/bVw3Y1F.png. It makes it easyer to stream then :/
[15:26] <StFS> Hi. I'm trying to record a specific window on my desktop and I've pretty much figured it out except that my command now records my microphone instead of recording the actual sound that's being played in my speakers... can someone help me figure out how I can do that?
[15:26] <StFS> The command I have is: ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s $WIN_GEO -i :0.0+$WIN_XY -acodec libvo_aacenc -vco    dec libx264 -vpre lossless_ultrafast -threads 0 -y $1.mkv
[15:41] <Stels> StFS: Open "pavucontrol", and select capture settings.
[15:48] <StFS> Stels: hmmm... I don't see any Capture settings there?
[15:54] <LithosLaptop> not related to the problem, but any reason why you are using libvo_aacenc?
[15:55] <LithosLaptop> even the experimental built-in aac encoder gives better quality than libvo_aacenc :)
[15:59] <StFS> oh? no... I just saw a warning when I tried using aac... it told me I had to add some option or use this one...
[15:59] <LithosLaptop> -strict -2
[16:00] <StFS> ok... I'll use that then :)
[16:00] <LithosLaptop> oh wait
[16:00] <LithosLaptop> did it tell you other ones also?
[16:00] <StFS> nope
[16:00] <LithosLaptop> oh ok
[16:02] <LithosLaptop> for the built-in aac encoder I find a bitrate of 256kbit/s and a -cutoff 15000 to sound ok
[16:03] <StFS> ok so now -vpre doesn't seem to work
[16:12] <StFS> LithosLaptop: nevermind... I had changed the command to avconv and that apparently doesn't support -vpre
[16:12] <LithosLaptop> ah ok
[16:13] <StFS> buuuut... unfortunately I'm still having trouble getting it to record the audio from the application rather than the mic
[16:17] <StFS> when I record I see the application pop up in pavucontrol and I can change the "capture from" for ffmpeg but none of them work except the microphones
[16:22] <StFS> ahh.. the "Monitor of Built-in Audio Analog Stereo" input device was muted. Things work fine when I unmuted that :)
[16:22] <StFS> I would like to be able to do this from the CLI though... but this is better than nothing :)
[18:52] <jomp16> Hey, newbie question: how to compile FFMPEG for Android ARMv7 NEON?
[18:53] <atiti> hey guys, I'm trying to encode some v4l footage to mpeg-ps and have it returned in a buffer in the memory. For that I've setup a custom AVIOContext and did avformat_open_input() with an empty ("") file
[18:54] <atiti> but I'm getting "Invalid data found when processing " while trying to do avformat_open_input()
[19:14] <atiti> i guess noones here
[19:16] <zap0> why?
[19:18] <atiti> cos noones talking
[19:39] <atiti> http://pastebin.com/1zbLnLA9 < anyone has any idea why it segfaults at av_set_parameters() ?
[19:45] <klaxa> when in doubt, valgrind?
[19:57] <atiti> not a bad idea, i thought your gona say gdb tho :p
[19:59] Action: ubitux wonders what av_set_parameters is
[20:01] <atiti> "Set the output parameters of the output video context (see output_example). Must be done even if no parameters in order to prepare the output format context." (http://wiki.aasimon.org/doku.php?id=ffmpeg:av_set_parameters)
[20:49] <Smashcat> Hi, I'm having a weird issue with ffmpeg trying to create a video and transpose it "90 degrees clockwise") using ffmpeg -y -r 25 -i %04d.png -c:v libx264 -s 720x1280 -pix_fmt yuv420p -crf 15 -vf "transpose=1" out.mov - it rotates the content, but the video remains in portrait format. Using the exact same command in avconv, it's landscape.
[20:50] <Smashcat> ... However, with some PNG's, ffmpeg does rotate it to landscape. Even though the input PNGs are exactly the ame width/height. Is there some metadata ffmpeg reads that prevents it from rotating correctly?
[21:44] <Smashcat> Seems that reversing the width height works in ffmpeg. Love it when projects fork and they start changing options to break compatibility :)
[00:00] --- Mon Apr 15 2013