[Ffmpeg-devel-irc] ffmpeg.log.20151109

burek burek021 at gmail.com
Tue Nov 10 02:05:01 CET 2015


[00:31:21 CET] <shevy> when merging some short .mp4 files, I'd like to insert a blank black screen for, say, 3 seconds between these individual video files. is there a way to do this with ffmpeg? e. g. if one could create a 3 seconds black video, this should suffice, I could then re-use this via a script
[00:32:06 CET] <c_14> color=black:d=3
[00:32:23 CET] <shevy> ok, thanks, lemme try that
[01:48:31 CET] <shevy> hmm ffmpeg seems to create files such as intermediate1.ts
[02:20:45 CET] <fahadash> How do I extract a particular frame from the video and save it as a png file?
[02:21:01 CET] <c_14> By number or by timestamp?
[02:21:27 CET] <fahadash> timestamp
[02:21:43 CET] <c_14> ffmpeg -ss timestamp -i video -frames:v 1 out.png
[02:22:00 CET] <fahadash> Let me try
[02:24:28 CET] <fahadash> How should the timestamp be specified?
[02:24:35 CET] <fahadash> seconds or in the format of 00:00:00 ?
[02:24:39 CET] <c_14> either or
[02:24:55 CET] <fahadash> Damnit, I bet aliens built ffmpeg
[02:25:16 CET] <fahadash> It always already has every feature that I imagine it should have
[02:26:30 CET] <fahadash> It works
[02:27:18 CET] <fahadash> I have never come across a product so perfect as ffmpeg
[02:44:38 CET] <shevy> lots of manhours of developer time went into it
[03:07:10 CET] <PovAddict> Stream #0:2(und): Data: none (mebx / 0x7862656D), 46 kb/s (default)
[03:07:13 CET] <PovAddict> does anyone know what that is?
[07:08:12 CET] <dongs> fat chance I know, but would anyone know if ffmpeg can deal wiht dvb-s2 generic stream / continous stream encapsulated stuff?
[07:09:50 CET] <jasom> Any idea why I would be able to encode 4 files separately with no issue, but when I use concat ffmpeg starts dumping error messages like crazy to the output; mostly "frame duplication too large"
[07:10:24 CET] <dongs> are you trying to concat mp4s
[07:10:26 CET] <jasom> sources are all ATSC mpeg2 title streams
[07:10:28 CET] <dongs> or mpeg ts
[07:10:29 CET] <dongs> yeah
[07:10:50 CET] <dongs> i had same shit, i forgot what I had to do but it involved wasting tons of diskspace for intermediate files
[07:11:02 CET] <jasom> *sigh*
[07:11:03 CET] <dongs> basically ts -> concat = not gonna work
[07:11:35 CET] <dongs> iirc i had to go to mp4 or something first, with some special options, then combine those.
[07:11:41 CET] <jasom> in general I've had very little luck with ffmpeg and things recorded over the air; a single uncorrected frame makes it go all haywire; I've been using mplayer as a frameserver to work around it
[07:13:24 CET] <dongs> eh, well
[07:13:39 CET] <dongs> mpegts doenst really leaev a lot for correction but
[07:14:23 CET] <dongs> generally a trashed packet or packet with TEI shouldn't affect too much
[07:14:29 CET] <jasom> well I'd like my encoder to be as accepting of input as my player
[07:14:41 CET] <dongs> you'll get a video glitch and shit but it shouldnt crap stuff out completely
[07:15:14 CET] <jasom> dongs: that's what happens when I play it with vlc or mplayer, but ffmpeg will do very odd things (including aborting)
[07:18:38 CET] <dongs> ah
[07:18:40 CET] <dongs> well that sucks
[07:18:57 CET] <dongs> i had a simliar problem with tsreader until i disabled the thumbnail preview.
[07:25:20 CET] <jasom> Anyway I'll go back to mplayer with yuv4mpeg and -fixed-vo I get a noticable pop in the audio, but it otherwise works fine
[09:34:47 CET] <t4nk719> Trying to node.js with ffmpeg for voice music bot.
[09:35:04 CET] <t4nk719> So far, I found out, larger file sizes take lots of time to encode than smaller sizes
[09:35:07 CET] <t4nk719> 				var enc = spawn(selection , [ 					'-i', file, 					'-f', 's16le', //s161e 					'-ar', '48000', 					'-ac', '1', 					'libmp3lame', 					'-stdin', 					'pipe:1' 				]);
[09:35:27 CET] <t4nk719> By longer, means like 30 seconds longer.
[09:35:37 CET] <t4nk719> I have an i7, thought it should convert rather quickly
[10:26:06 CET] <JamJams> Hey, when using a filter graph is there and easy way to reset it? For seaking, I want to flush my filter graph much like I do for the decoder.
[10:28:37 CET] <JamJams> Never mind I see there's no way to do that. Must be recreated.
[10:31:20 CET] <claz> hi, I have a video file with timestamps starting at 30s , is there any command that will fix this without transcoding it?
[11:24:13 CET] <relaxed> claz: try, ffmpeg -ss 30 -i input -c copy out
[14:21:48 CET] <abd5932> Hello, why file with this parameters http://paste.debian.net/330006/ doesn't play on a smartphone (samsung)? Thank you!
[14:22:20 CET] <waressearcher2> abd5932: hallo
[14:22:30 CET] <PovAddict> Stream #0:2(und): Data: none (mebx / 0x7862656D), 46 kb/s (default)
[14:22:31 CET] <PovAddict> does anyone know what that is?
[14:23:23 CET] <abd5932> waressearcher2: hallo
[14:27:38 CET] <furq> abd5932: some android phones only support h.264 baseline
[14:28:34 CET] <abd5932> furq: how do I have to encode, so it works also there (better everywhere)? Thank you!
[14:29:06 CET] <furq> -profile:v baseline
[14:31:55 CET] <abd5932> furq: I used -vprofile main till now... can your solution introduce some regression?
[14:32:13 CET] <abd5932> (i.e. it will stop working on some desktops?)
[14:32:28 CET] <furq> no
[14:32:37 CET] <DHE> baseline will play pretty much anywhere, but you may need to raise the bitrate to keep the quality up
[14:32:40 CET] <furq> baseline just isn't as good
[14:32:44 CET] <furq> cabac is disabled, for starters
[14:32:49 CET] <DHE> then again the source is 1 megabit 1080p so who knows...
[14:34:11 CET] <abd5932> thank you! I'll try!
[14:59:45 CET] <waressearcher2> why I getting different results when I encode two times, first with  -vf "curves=preset=cross_process" and then -vf "curves=blue='0.5/0.58'"   in compare if I do one encoding with this filter -vf "curves=preset=cross_process:blue='0.5/0.58'" ?
[15:03:45 CET] <waressearcher2> hallo ?
[15:04:59 CET] <fritsch> this is not your personal help channel - so keep calm and wait
[15:05:19 CET] <mkay_> is there a parameter to use to make sure the conversion is not lossy?
[15:05:59 CET] <mkay_> if I want to convert a animated gif to mp4 (to let VLC play it) without any loss of quality
[15:06:22 CET] <waressearcher2> fritsch: wovon redest du eigentlich ?
[15:07:41 CET] <mkay_> hello waressearcher2, need any help?
[15:07:58 CET] <waressearcher2> fritsch: bist du wahnsinn ?
[15:18:42 CET] <ubitux> waressearcher2: cross_process is r="0.25/0.156 0.501/0.501 0.686/0.745" g="0.25/0.188 0.38/0.501 0.745/0.815 1/0.815" b="0.231/0.094 0.709/0.874"
[15:19:21 CET] <ubitux> copy these settings and change the blue field to your custom values
[15:28:04 CET] <mkay_> in this case the resulting file size is not important, I will delete the file after looking, can I set some bitrate to some stupid high value?
[15:44:07 CET] <mkay_> hmmm.... is it possible to have ffplay play a video in slowmotion?
[15:44:52 CET] <BtbN> you could try using the setpts filter and add a multiplier to the timestamps
[15:45:01 CET] <mkay_> ok
[15:58:34 CET] <c_14> mkay_: use a lossless codec or libx264 in lossless mode
[16:05:59 CET] <mkay_> c_14: oh, how do I do that?
[16:06:26 CET] <c_14> Which one?
[16:07:16 CET] <mkay_> c_14: as long as vlc can play it without problem I guess any format is good..
[16:07:29 CET] <c_14> -c:v ffv1
[16:07:34 CET] <mkay_> ok thanks
[17:09:46 CET] <yangm> sup
[17:11:45 CET] <yangm> I would like to write metadata from the file creation date and then format the file name as yyymmdd hhmmss.extension
[17:12:05 CET] <yangm> I did a similar thing to my jpeg files using jhead
[17:12:15 CET] <yangm> is it possible to do using ffmpeg?
[18:37:46 CET] <menacer> Hi folks
[18:37:52 CET] <menacer> Was wondering if you could help me
[18:38:57 CET] <menacer> I am looking for ffmpeg to continously watch a folder so that it adds an intro to any file coming in to the folder and then once the intro is added it is sent to the folder of my choice?
[18:42:34 CET] <Filarius> make script what will be by scheldure check if there is files in folder and run encoding if yes
[18:43:28 CET] <menacer> Thanks i'll try and do some research in to this
[18:43:28 CET] <furq> menacer: http://linux.die.net/man/1/inotifywait
[18:44:30 CET] <menacer> Thnaks furq, this is running on windows, will this still apply? I'm very new to all this.
[18:45:52 CET] <ps-auxw> inotify is pretty linux specific, so that's unlikely.
[18:46:06 CET] <furq> https://github.com/thekid/inotify-win
[18:46:10 CET] <furq> there's that but you'd need to compile it yourself
[18:46:32 CET] <furq> there's probably some equivalent but nothing i know offhand
[18:47:25 CET] <menacer> Thanks very much.
[18:48:40 CET] <fritsch> https://msdn.microsoft.com/en-us/library/system.io.filesystemwatcher.aspx
[18:50:08 CET] <menacer> Thanks very much furq and fritsch
[18:50:25 CET] <menacer> and ps-auxw
[18:51:07 CET] <fritsch> there are also some hacks with windows powershell
[18:51:41 CET] <furq> http://superuser.com/a/844034/146437
[18:52:32 CET] <furq> i always forget you can just call .net stuff with powershell
[18:55:04 CET] <menacer> I am so lost on all this lol
[18:55:54 CET] <ZIMASTRO> ciao a tutti
[19:04:20 CET] <chat1234> is anyone else having problems with the nvenc_hevc encoder?
[19:04:48 CET] <chat1234> i'm able to use the nvenc_h264 just fine, but the hevc version gives an error "No NVENC capable devices found"
[19:05:12 CET] <fritsch> which gpu do you have?
[19:05:26 CET] <chat1234> GeForce GTX 750 Ti
[19:05:40 CET] <fritsch> that is to my knowledge too old for hevc encoding
[19:05:47 CET] <fritsch> but wait for BtbN - he knows for sure
[19:06:05 CET] <chat1234> ok
[19:06:07 CET] <chat1234> thanks
[19:06:27 CET] <fritsch> I think you need a Maxwell GM20x generation
[19:06:30 CET] <fritsch> https://en.wikipedia.org/wiki/Nvidia_NVENC
[19:06:32 CET] <fritsch> see ^^
[19:06:42 CET] <furq> you need a 950 or better
[19:07:00 CET] <BtbN> well, "better"
[19:07:08 CET] <BtbN> The hevc situation is kinda weird
[19:07:18 CET] <BtbN> But basicaly, 900 series or more recent
[19:07:20 CET] <BtbN> for encoding
[19:07:35 CET] <furq> yeah better is probably a bad choice of word
[19:07:51 CET] <BtbN> For decoding, a 950 works
[19:07:54 CET] <BtbN> but a 980 doesn't.
[19:08:46 CET] <chat1234> well that'd explain why it isn't working on mine
[19:09:06 CET] <chat1234> if i were to get a new graphics card for hevc/gaming, any suggestions?
[19:10:27 CET] <fritsch> chat1234: nope - no idea about gaming. For hevc encoding - check that maxwell cards
[19:10:30 CET] <BtbN> It's not realy worth getting a card just for nvenc hevc encoding.
[19:10:43 CET] <BtbN> x264 still beats it in terms of quality
[19:11:06 CET] <chat1234> good to know
[19:11:09 CET] <chat1234> thanks guys!
[19:45:08 CET] <yangm> [14:11:44] yangm:	I would like to write metadata from the file creation date and then format the file name as yyymmdd hhmmss.extension
[19:45:08 CET] <yangm> [14:12:05] yangm:	I did a similar thing to my jpeg files using jhead
[19:45:08 CET] <yangm> [14:12:15] yangm:	is it possible to do using ffmpeg?
[20:34:16 CET] <waressearcher2> yangm: hallo
[20:34:37 CET] <yangm> waressearcher2, sup
[20:34:46 CET] <waressearcher2> yangm: wie gehts ?
[20:35:00 CET] <yangm> what
[20:54:09 CET] <durandal_1707> kick waressearcher2
[21:38:30 CET] <Unknown__> [yuv4mpegpipe @ 0x14a7260] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8) [u16le @ 0x1466de0] Thread message queue blocking; consider raising the thread_queue_size option (current value: 2512) /tmp/mcs_v_all: Invalid data found when processing input.
[21:38:33 CET] <Unknown__> How to fix?
[21:38:56 CET] <waressearcher2> durandal_1707: böse böse böse
[21:40:50 CET] <durandal_1707> ban
[21:53:20 CET] <waressearcher2> Unknown__: guten morgen
[21:53:38 CET] <Unknown__> Hello can you help me?
[21:54:36 CET] <waressearcher2> "consider raising the thread_queue_size option" ?
[21:56:10 CET] <Unknown__> I did (current value: 2512)
[21:56:36 CET] <Unknown__> ffmpeg -thread_queue_size 2512
[21:56:42 CET] <Unknown__> Higher than this ?
[21:59:37 CET] <waressearcher2> Unknown__: Ich habe echt keine Ahnung
[21:59:55 CET] <Unknown__> I don't understand german
[22:15:55 CET] <techtopia> hello
[22:16:10 CET] <techtopia> -sn will remove subtitles from an encode?
[22:17:09 CET] <c_14> yes
[22:17:19 CET] <techtopia> thanks :)
[22:17:41 CET] <techtopia> c_14, i have a file with multiple subtitles and i want to keep them all
[22:17:47 CET] <techtopia> will this be done by default
[22:17:56 CET] <techtopia> or is it somthing i have to do with -map ?
[22:17:56 CET] <c_14> No
[22:18:00 CET] <c_14> You have to use -map
[22:18:08 CET] <techtopia> ok, will do some reading
[22:59:19 CET] <shevy> does anyone happen to know if ffmpeg is able to find out the average decibel level of an .mp3 file? the recording happened via a voice recorder in the open area (e. g. not inside a house or anything). I would need to compare the different noise levels from different datasets recorded with the same voice recorder
[23:02:09 CET] <c_14> There's an audio filter for that
[23:02:11 CET] <c_14> somewhere
[23:02:21 CET] <c_14> volumedetect
[23:02:28 CET] <shevy> ok thanks c_14
[00:00:00 CET] --- Tue Nov 10 2015


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