[Ffmpeg-devel-irc] ffmpeg.log.20150105

burek burek021 at gmail.com
Tue Jan 6 02:05:01 CET 2015


[00:04] <zumba_ad_> hi folks, what's missing from my command, I couldn't hear the audio? ffmpeg -i output.mp4 -i song.aac -c:v copy -c:a copy output3.mp4
[00:04] <schiho> Is it possible to force constant delay when streaming?
[00:05] <schiho> so the delay varys between 200ms and 300ms it is more important for me to have all the time 300ms rather then fluctuating delay
[01:27] <chan1> chan1
[01:29] <chan1> sfan5: thanks. I tried "ffmpeg -i file1.MTS -c file1.mkv" but it doesn't work.
[01:29] <chan1> ffmpeg -h tells me I have to give codec name after -c.
[01:29] <chan1> How do you use -c option? (I want to bypass transcoding. want to just copy the video, audio, just different container file format)
[01:32] <c_14> -c copy
[01:33] <llogan> and add -map 0 if you want to include all streams
[01:40] <chan1> c_14, llogan : Thanks a lot! I tried "ffmpeg -i 20121129133142.MTS -c copy 20121129133142.avi" and it worked!
[02:56] <k_sze[work]> I have run into a tough problem.
[02:56] <k_sze[work]> I'm trying to encode infrared video from Kinect for Windows v2.
[02:56] <k_sze[work]> But the video is really huge as FFV1.
[02:57] <k_sze[work]> (unsigned 16-bit grayscale)
[02:57] <xreal> I want to compress a video using ffmpeg and play it by ffplay. Piping doesn't seem to work: "pipe:: Invalid data found when processing input" - what am I doing wrong?
[02:57] <k_sze[work]> I'm trying to identify some other codec, even if that means lossy.
[02:57] <k_sze[work]> but there seems to be none that supports 16-bit grayscale.
[02:59] <k_sze[work]> (I know libopenjpeg does 16-bit grayscale and it can be lossy, but it seems to be bugged in the recent revisions of ffmpeg)
[03:06] <zacarias> Hi. I want to burn subtitles onto a mpeg file, which has a birate of around 2200 kbps. But if I just use the default options (ffmpeg -i video.avi -vf subtitles=subtitle.srt out.avi) I get a low-quality video with a bitrate of around 900 kbps. How should I do this?
[03:08] <c_14> Increase the bitrate?
[03:13] <zacarias> c_14: Is the question for me?
[03:13] <c_14> Less of a question, more of a suggestion.
[03:14] <c_14> And yes, for you.
[03:16] <zacarias> c_14: That's it. But I tried to add this (-b:v 2200k -bufsize 2200k ) just after the input filename and it gives me an error. The command was: ffmpeg -i video.mp4 -b:v 2200k -bufsize 2200k -vf subtitles=subtitle.srt out.avi)
[03:17] <c_14> You don't need bufsize
[03:18] <zacarias> c_14: ok... I'll try without it. I don't know if the automatic reduction of bitrate has anything to do with the fact that the original mp4 has a h264 encoding, and ffmpeg automatically encodes it with xvid
[03:20] <c_14> You'll probably want to force h264
[03:20] <zacarias> c_14: Oh! Is it possible?
[03:21] <c_14> If your version of ffmpeg has libx264 support, ye.
[03:21] <c_14> Just add -c:v libx264
[03:22] <c_14> In which case you might also want to look into -crf. Something around 18 is usually considered visually lossless.
[03:23] <zacarias> c_14: ok, I'll try it if the option with just increasing the bitrate doesn't fit my needs. Just another questions: -c:v libx264 or -crf should be put where (sorry for my ignorance)?
[03:23] <c_14> somewhere in front of the output file
[03:23] <c_14> but it has to be after the input filename[s]
[03:26] <zacarias> c_14: thanks. So should I make something like: ffmpeg -i video.mp4 -c:v libx264 -crf 18 -vf subtitles=subtitle.srt out.avi?
[03:27] <c_14> ye
[03:28] <zacarias> c_14: Thanks for your precious help!
[03:33] <Demon_Fox> What would I use to slice up a video file into smaller ones losslessly given I can get the exact times for everything?
[03:33] <c_14> A lossless codec?
[03:33] <Demon_Fox> I mean
[03:33] <Demon_Fox> -vcodec copy
[03:33] <Demon_Fox> (Not sure if that incurs loss though.)
[03:34] <Demon_Fox> Well, it is a huge mpeg2 file.
[03:34] <c_14> It shouldn't, but you can only cut on iframes
[03:34] <Demon_Fox> key frames?
[03:34] <c_14> ye
[03:35] <Demon_Fox> Not exactly sure how the dvd people made it
[03:36] <Demon_Fox> It would matter much c_14
[03:36] <Demon_Fox> It ends in black before starting the next one
[03:36] <Demon_Fox> So it probably hits a keyframe
[03:37] <Demon_Fox> c_14, How would I do it though?
[03:37] <c_14> ffmpeg -ss [from] -t [duration] -i file [options] outfile
[03:37] <Demon_Fox> Thanks c_14
[03:38] <Demon_Fox> c_14, By chance do you know if ffmpeg will copy multiple audio channels?
[03:38] <c_14> add -map 0:a
[03:38] <c_14> It doesn't by default.
[03:39] <Demon_Fox> Will it also copy the subtitles over?
[03:39] Action: Demon_Fox should probably check the format on those.
[03:39] <c_14> It will copy 1 track by default. add -map 0:s and it'll copy them all
[03:40] <c_14> You'll want '-c copy'
[03:40] <Demon_Fox> Thanks c_14
[03:55] <k_sze[work]> Hmm, so jpegls supports gray16le
[03:56] <k_sze[work]> Does ffmpeg's jpegls support near-lossless mode?
[04:58] <codehero> today i learned that i shouldn't use -vcodec copy -acodec copy when trimming videos...
[06:23] <ParkerR> Well my ffpmeg experience may get better after all
[06:26] <tdr> codehero yeah, there's a differnet way to do the same thing that is more correct
[06:55] <rcombs> codehero: you can do that for audio if you throw in `-copypriorss:a 0`
[09:06] <Akagi201> Could someone help me to provide a ffmpeg static build script or options?
[09:07] <Akagi201> I found http://ffmpeg.gusari.org/static/ and http://johnvansickle.com/ffmpeg/ but I don't find a working script
[09:26] <Akagi201> relaxed: Could you provide a static build script?
[09:26] <Akagi201> Or give me some ideas to do it.
[10:35] <bahathir> Hi... I have problem playing youtube URL links, since several git versions.
[10:35] <bahathir> It segfaulted.
[10:36] <bahathir>  ffplay https://www.youtube.com/watch?v=0j5ttFMqbFM
[10:36] <bahathir> ffplay version N-53543-g32c836c Copyright (c) 2003-2014 the FFmpeg developers
[10:36] <bahathir>   built on Dec 23 2014 15:52:25 with gcc 4.9.2 (GCC)
[10:36] <bahathir>   configuration: --prefix=/usr --shlibdir=/usr/lib64 --libdir=/usr/lib64 --enable-shared --disable-static --enable-gpl --enable-pthreads --enable-nonfree --enable-postproc --enable-x11grab --enable-libmp3lame --enable-libdc1394 --enable-libbluray --enable-libquvi --enable-vdpau
[10:36] <bahathir>   libavutil      54. 15.100 / 54. 15.100
[10:36] <bahathir>   libavcodec     56. 16.100 / 56. 16.100
[10:36] <bahathir>   libavformat    56. 16.101 / 56. 16.101
[10:37] <bahathir>   libavdevice    56.  3.100 / 56.  3.100
[10:37] <bahathir>   libavfilter     5.  4.100 /  5.  4.100
[10:37] <bahathir>   libswscale      3.  1.101 /  3.  1.101
[10:37] <bahathir>   libswresample   1.  1.100 /  1.  1.100
[10:37] <bahathir>   libpostproc    53.  3.100 / 53.  3.100
[10:37] <bahathir>     nan    :  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0
[10:37] <bahathir> /0
[10:37] <bahathir> 0B f=0/0
[10:37] <JuanDosSantos> Hi, is it possible to send output stream to a http socket? So that I can access the stream trought a http proxy like nginx?
[10:37] <bahathir> q=    0B f=0/0
[10:37] <bahathir>  0KB sq=    0B f=0/0
[10:37] <bahathir> vq=    0KB sq=    0B f=0/0
[10:37] <bahathir>   0KB vq=    0KB sq=    0B f=0/0
[10:37] <bahathir>  aq=    0KB vq=    0KB sq=    0B f=0/0
[10:38] <bahathir> Actually, previously, ffplay able to to playback the URL without any problem/
[10:40] <bahathir> Ok, thank you. I try to send the bug the ffmpleg mailing list later. :)
[10:41] <bahathir> exit
[10:43] <JuanDosSantos> If i try to create a http output I get this error: [tcp @ 0xa63600] Connection to tcp://127.0.0.1:8099 failed: Connection refused \n http://127.0.0.1:8099/test.ts: Input/output error
[10:44] <JuanDosSantos> ffmpeg -i http://10.8.0.10:8000/stream.ts -c copy http://127.0.0.1:8099/test.ts
[10:45] <Mavrik> JuanDosSantos, ffmpeg isn't going to create an HTTP server for you
[10:45] <Mavrik> JuanDosSantos, ffserver does that
[10:46] <Mavrik> what you're trying to do is send data to a server that listens over HTTP protocol for incoming video
[10:47] <JuanDosSantos> ye but ffserver is no longer maintained..
[10:48] <Mavrik> if that's a concern, you'll have to get a streaming server then
[10:48] <Mavrik> there's several out there, from commercial to opensource
[10:48] <JuanDosSantos> Do you know a opensource project for that?
[10:49] <Mavrik> Depends on your requirements.
[10:49] <JuanDosSantos> need only a http listener, to send stream data to it..
[10:49] <Mavrik> But I didn't find anyting opensource that would work significantly better than ffserver, we used Wowza for pro streaming (which is probably too expensive for you)
[10:49] <Mavrik> JuanDosSantos, that means nothing
[10:49] <Mavrik> JuanDosSantos, the important part is: which protocol, which clients, who wants to watch and in what way
[10:50] <Mavrik> also which video format
[10:50] <JuanDosSantos> Mavrik: I need only mpegts...
[10:55] <JuanDosSantos> Mavrik: Ok I will try again with ffserver...
[12:09] <kaotiko> hi
[13:35] <chan1> hi, all, how do we know the video and audio type of an avi file?(without converting it)
[13:42] <Fjorgynn> chan1: what?
[13:42] <Fjorgynn> ffmpeg -i file.avi
[13:59] <Fjorgynn> lifeofguenter: :D
[14:10] <Fjorgynn> it's more activity in a vacum than here
[14:12] <d_ferdi> hello, i have a problem with ffmpeg and mp4: first run: ffmpeg insert many dupe frames and increase the playlenght by 15%, second run with other parameters video is ok for virtualdub, but other progs (vlc,zoomplayer) display same playlength as first time with video/audio async and 15% black videotime at the end
[14:27] <d_ferdi> http://pastebin.com/pfxaeM5h
[14:28] <d_ferdi> there is a difference of 20 minutes between input and output but both have a fps of 25
[14:46] <d_ferdi> how can audio be 20 minutes longer as video ?
[14:47] <d_ferdi> http://pastebin.com/mHAbt1u3
[14:53] <d_ferdi> why says ffmpeg, that a 03:23:09.65 mp2-audio file is 03:53:53.28 long, if i demultiplay and save the audio ?
[15:26] <d_ferdi> i convert the mp2-audio-channel with Duration 03:23:09.65 (ffprobe) to acc with time Duration: 03:40:08.73 (ffprobe), mux them with ffmpeg to video with  Duration 03:23:09.65 (ffprobe) and video/audio are sync. this is impossible!
[16:30] <eyal-ff> Hey, I have a question about monitoring stream. Does anyone knows if it's possible to monitor a live stream (that I publish with ffmpeg) and get information about current framerate, bitrate and more?
[18:00] <Teilio> hi im trying to find a way of handling latm audio without reencoding it. is there a way to alter the bitstream so that it can be changed to adts/raw aac?
[18:00] <Teilio> videoredo seems to be able to do this thanks to ffmpeg but i can't work out how to do this in ffmpeg itself
[18:11] <xreal> I've got a ts stream, which is PAL already. Does ffmpeg do fast copy or a complete reencoding when using -target pal-dvd ?
[18:13] <kepstin-laptop> by default it'll do a reencode; the main use of the 'pal-dvd' target is that it sets up the codec parameters correctly for dvd.
[18:15] <xreal> kepstin-laptop: So I shoud do it manually and use -f vob ?
[18:16] <xreal> it's a ts-stream from DVB-S btw
[18:16] <kepstin-laptop> if your video and audio streams are both already in codecs supported on DVD, and are within the allowed bitrate for DVD, then that should work.
[18:17] <xreal> kepstin-laptop: since it's DVB-S it should work, shouldn't it?
[18:20] <xreal> Overall bit rate: 4 339 Kbps - should be okay? :)
[18:20] <xreal> mmh, there's also -f dvd
[18:21] <xreal> they're equal
[18:21] <kepstin-laptop> i dunno, you'd have to check the codecs used.
[18:22] <xreal> kepstin-laptop: http://todayiwantedtoprogram.tumblr.com/post/15142587796/what-does-ffmpegs-target-pal-dvd-actually-do
[18:22] <xreal> Thanks for help :D
[18:23] <xreal> Funny: Stream #0:2 -> #0:1 (mpeg2video -> mpeg2video)
[18:23] <xreal> ffmpeg should make this "copy" automatically :(
[18:24] <kepstin-laptop> assuming that the video in your stream is already mpeg2 and the audio is one of pcm, mp2, or ac3, you're probably ok with just a remux to vob.
[18:25] <kepstin-laptop> copy is a bit of a special case, a lot of the ffmpeg functionality is disabled when you use it. so it doesn't normally make sense to use automatically
[18:26] <xreal> okay, let me play around, thanks again
[19:40] <bttf> question ... is it possible to capture stills from a video file using ffmpeg, and if so where is a good place to start to read more about it?
[19:42] <bttf> nvm .. i found it in http://ffmpeg.org/ffmpeg.html#Video-Options
[19:42] <bttf> sry, http://ffmpeg.org/ffmpeg.html#Video-and-Audio-file-format-conversion
[20:48] <ChocolateArmpits> Are there any known compatibility problems with proxy profile prores? Premiere crashed when I tried to import some of the converted files. The "standard" profile is handled well.
[21:53] <squeegily_> I have some MKV files with H.264 video and styled subs. Is there a way to convert them to MP4 (or some other PS3-compatible format), keeping the subtitles, but *without re-encoding the video*? I'm suspecting something along the lines of converting the subtitles to some sort of overlay..? Google didn't turn up anything useful find anything
[21:54] <llogan> softsub support in MP4 isn't great. i doubt PS3 can play mov_text subs.
[21:54] <squeegily_> llogan: Thanks. :(
[21:54] <llogan> and i'm not sure what other formats the PS3 supports.
[21:54] <c_14> http://manuals.playstation.net/document/en/ps3/current/video/filetypes.html
[21:55] <squeegily_> llogan: I've seen it choke on some AVIs so I have pretty little faith in it
[21:55] <c_14> Basically, nothing interesting.
[21:55] <JEEB> the best bet for such devices is to re-encode with mpv which easily lets you keep the styled subtitles
[21:55] <JEEB> unlike ffmpeg, with which you have to extract fonts and the subtitles first
[21:55] <c_14> you don't have to
[21:56] <c_14> the subtiles filter does all that
[21:56] <llogan> ffmpeg -i input.mkv -vf subtitles=input.mkv
[21:56] <llogan> i think...
[21:56] <JEEB> so it registers fonts and gets the subtitles these days?
[21:56] <c_14> yep
[21:56] <c_14> Works for me anyways
[21:56] <squeegily_> JEEB: yeah, right now if I want to watch anime on the PS3 I have to wait like an hour for the video to re-encode and burn in the subtitles
[21:56] <JEEB> c_14, the first part is usually quite important :P
[21:57] <JEEB> if ffmpeg can do it then it's sure great of course
[21:57] <JEEB> the last I checked something like mpv was the quicker and simpler choice, though
[21:57] <squeegily_> ffmpeg does a really good job - they're rendered the way they're supposed to be
[21:57] <kepstin-laptop> squeegily_: yeah, no other option :/ even the crunchyroll ps3 app needs a special encode with the hardsubs burned in...
[21:57] <JEEB> why does everyone actually ignore the one point I'd like the answer for :P
[21:58] <JEEB> does it actually register the fonts included in the matroska file
[21:58] <squeegily_> ouch. Oh well I guess that's what I get for going with a proprietary OS.. :/
[21:58] <squeegily_> JEEB: yes, it works
[21:58] <JEEB> if it uses libass then it's pretty fucking simple to actually render the subs
[21:58] <JEEB> ok, thank you
[21:58] <JEEB> for whatever reason I didn't get any comments on the fonts side of things
[21:58] <squeegily_> I'll test it out with the SAO II subs as the ultimate benchmark
[21:58] <squeegily_> They've got so many particle effects it hangs any media player I try
[21:58] <JEEB> anyways, then it's quite much more usable than it was
[21:58] <JEEB> uhh
[21:59] <squeegily_> Did it not used to be good?
[21:59] <JEEB> it was not exactly simple to use :P
[21:59] <JEEB> you had to register the fonts, then extract the subs
[21:59] <llogan> what's "Memory Stick Video Format" as mentioned in c_14's PS3 link
[21:59] <JEEB> then you could use the ass filter to use libass to render it
[21:59] <squeegily_> I didn't realize it used to be inconvenient
[21:59] <JEEB> so it could do the job, but it required all kinds of things the players doing the same thing didn't :P
[22:01] <llogan> squeegily_: i guess you'll just have to use a faster encoding preset
[00:00] --- Tue Jan  6 2015


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