[Ffmpeg-devel-irc] ffmpeg.log.20170514
burek
burek021 at gmail.com
Mon May 15 03:05:01 EEST 2017
[00:15:18 CEST] <arp> hello
[02:39:05 CEST] <hataki> hi, I have issue with this command....ffmpeg -i "a2.flac" -ss 0 -t 91 -acodec copy "axxxxxxx.flac"...output has 91 seconds audio but duration is still as input file...ffmpeg version N-85750-ga75ef15
[02:53:48 CEST] <klaxa> huh that's weird
[02:56:53 CEST] <hataki> General Complete name : C:\Users\hp\Videos\a2.flac Format : FLAC Format/Info : Free Lossless Audio Codec File size : 247 MiB Duration : 24 min 9 s Overall bit rate mode : Variable Overall bit rate : 1 426 kb/s Writing application : Lavf57.72.101 Audio Format : FLAC Format/Info : Free Lo
[02:57:19 CEST] <hataki> General Complete name : C:\Users\hp\Videos\axxxxxxx.flac Format : FLAC Format/Info : Free Lossless Audio Codec File size : 18.1 MiB Duration : 24 min 9 s Overall bit rate mode : Variable Overall bit rate : 105 kb/s Writing application : Lavf57.72.101 Audio Format : FLAC Format/Info : Fr
[09:41:19 CEST] <tristandm> Hi, so I'm trying to use ffmpeg to stream from YouTube out to a file using the realtime (-re) parameter on the input stream (youtube source url, found with youtube-dl) and partially through the stream the socket disconnects. Any insight? https://pastebin.com/3sujwmZC
[09:45:24 CEST] <tristandm> Here's a better paste: https://pastebin.com/jM1fWN8e
[10:14:14 CEST] <Pandela> Wanna hear what photoshopped audio data sounds like?
[10:14:50 CEST] <c3r1c-Linux> Only if it takes a picture of brittany spears,a nd then sounds like her.
[10:15:31 CEST] <Pandela> kek
[10:15:40 CEST] <c3r1c-Linux> ;-)
[10:15:47 CEST] <Pandela> https://my.mixtape.moe/mphrio.mp3
[10:15:52 CEST] <Pandela> This'll have to suffice
[10:16:22 CEST] <cousin_luigi> Greetings.
[10:16:30 CEST] <Pandela> ayy lmao
[10:16:48 CEST] <cousin_luigi> How do I change the aspect ratio and also zoom into it by an arbitrary factor?
[11:01:47 CEST] <Pandela> thebombzen: https://my.mixtape.moe/elfsrj.mp3 :-aewdigasefkiusf)
[11:02:11 CEST] <thebombzen> You're the one who was playing with rawaudio <-> rawvideo stuff right
[11:02:44 CEST] <Pandela> Yee
[11:03:18 CEST] <Pandela> I encoded audio data into an image and photoshopped it lmao
[11:03:49 CEST] <thebombzen> yea I was the one who helped you with testsrc or what
[11:04:16 CEST] <Pandela> ya you showed me dat filter, was pretty dank
[11:04:41 CEST] <Pandela> I updated my shit and got gbrp16le
[11:05:46 CEST] <Pandela> https://a.yiff.moe/rxnyxz.png Moonlight Sonata
[11:06:31 CEST] <thebombzen> You should consider http://0x0.st/
[11:06:44 CEST] <thebombzen> temporary upload thing
[11:07:10 CEST] <Pandela> rad domain name
[11:07:12 CEST] <thebombzen> cause it's not like that stuff needs to be on the internet forever. so like if you're just sending someone a small file it's ideal
[11:07:32 CEST] <thebombzen> I mean imgur stores every image they've ever had ULed to them
[11:07:40 CEST] <furq> no they don't
[11:07:48 CEST] <Pandela> no u
[11:07:58 CEST] <thebombzen> I can view all the images I've ever ULed to them :O
[11:08:15 CEST] <furq> you can delete them all as well
[11:08:19 CEST] <furq> how about that
[11:09:27 CEST] <Pandela> delet this
[11:09:29 CEST] <Pandela> https://www.youtube.com/watch?v=dQw4w9WgXcQ
[11:10:12 CEST] <thebombzen> well okay
[11:10:13 CEST] <thebombzen> but I mean
[11:10:18 CEST] <thebombzen> unless you explicitly delete them
[11:10:20 CEST] <thebombzen> they're still going to be there
[11:10:26 CEST] <furq> or someone else has them taken down
[11:10:35 CEST] <thebombzen> I'm not saying the images are immortal
[11:10:40 CEST] <thebombzen> I'm saying they're not temporary
[11:10:45 CEST] <thebombzen> which isn't the same thing
[11:10:50 CEST] <thebombzen> they're not removed unless someone elects to remove them
[11:11:01 CEST] <furq> that sounds temporary to me
[11:11:12 CEST] <thebombzen> are you just being difficult for the sake of being difficult
[11:11:17 CEST] <furq> i might be
[11:11:27 CEST] <thebombzen> Pandela: either way you should check that out
[11:11:36 CEST] <thebombzen> and if you can't remember the command line, then....
[11:11:42 CEST] <Pandela> I shall
[11:12:00 CEST] <thebombzen> https://0x0.st/gT6.bin
[11:12:24 CEST] <Pandela> I usually use https://rduke.com/owlfarm/
[11:12:50 CEST] <thebombzen> I wrote a script that uploads the first argument to 0x0.st, takes the link provided and copies it into both clipboards
[11:13:30 CEST] <Pandela> That's pretty sexy
[11:13:55 CEST] <thebombzen> I made it do both cause I could never remember whether it was in the plain clipboard (middleclick) or the rich clipboard (Ctrl+V)
[11:14:06 CEST] <thebombzen> so it puts it in both
[11:15:03 CEST] <furq> ladies
[11:17:42 CEST] <Pandela> memes
[15:05:02 CEST] <cousin_luigi> Greetings.
[15:05:19 CEST] <cousin_luigi> I don't understand which operator to use to zoom in a video. zoompan? crop?
[15:12:08 CEST] <c_14> zoompan probably
[15:20:06 CEST] <cousin_luigi> How can I find out the values to use if I also want to change the aspect ratio at the same time?
[15:22:26 CEST] <c_14> crop,scale might be easier in that case
[15:35:12 CEST] <cousin_luigi> Indeed. But is there a way to preview the result with ffplay so that I don't have to wait for a full run of the conversion? Or perhaps I should convert my video only for a few seconds?
[15:35:23 CEST] <cousin_luigi> Well, a few seconds of the video, I mean.
[15:37:18 CEST] <c_14> usually just do a conversion of a few seconds, yeah
[15:37:40 CEST] <c_14> though if you use a format that supports playing as you encode you can just view that
[15:45:48 CEST] <cousin_luigi> c_14: Unfortunately the latter is not true.
[15:46:09 CEST] <c_14> hmm?
[15:46:14 CEST] <c_14> what format?
[15:46:31 CEST] <c_14> mpeg-ts should work and matroska if you enable live mode
[15:46:59 CEST] <cousin_luigi> h264 inside mp4. Could try mkv I suppose.
[15:47:10 CEST] <c_14> mp4 won't work
[15:47:13 CEST] <cousin_luigi> Indeed.
[15:47:27 CEST] <cousin_luigi> What's this live mode?
[15:47:29 CEST] <c_14> -live
[15:47:39 CEST] <c_14> might be -live 1
[15:47:41 CEST] <c_14> not sure
[15:54:19 CEST] <cousin_luigi> crop and aspect or setdar don't work together. Not sure how to use scale:/
[15:54:54 CEST] <c_14> crop the portion of the input you want to keep and then scale to the size you want it to end up as?
[15:57:20 CEST] <c_14> so if you want the center of your video, something like crop=700:600,scale=1400:1200
[15:57:35 CEST] <c_14> if you want the center 700:600 block and then want it x2
[16:36:12 CEST] <dl2s4> hi, why "ffmpeg -i input.mkv > text.txt" does not work?
[16:36:48 CEST] <JEEB> what on earth are you trying to do there?
[16:36:59 CEST] <JEEB> you haven't told ffmpeg to output anything to stdout yet you are piping it?
[16:37:15 CEST] <JEEB> if you just want the text, most tools output to stderr
[16:37:16 CEST] <dl2s4> i want to see the streams of the input.mkv and put the console output to a txt
[16:37:17 CEST] <JEEB> which is 2>
[16:37:38 CEST] <JEEB> stdout is generally not used because then you cannot pipe an actual output to a following process
[16:37:49 CEST] <JEEB> <one app> | <another app>
[16:37:56 CEST] <JEEB> this would be impossible if stdout was used for logging
[16:38:15 CEST] <dl2s4> 2> it is thanks
[16:38:25 CEST] <cousin_luigi> c_14: will try that, thanks!
[16:57:27 CEST] <cousin_luigi> How do I find out the current h264 quality of a clip so that I can supply an h265 equivalent crf?
[17:00:01 CEST] <BtbN> you can't
[17:00:16 CEST] <BtbN> if you already have a h264 version, there is rarely any point to re-compress
[17:04:30 CEST] <cousin_luigi> ok
[17:05:06 CEST] <cousin_luigi> well, now I have the right crop, the right quality but as soon as I force an aspect ratio, my window gets cropped further. How do I tell ffmpeg to use black bands?
[17:05:37 CEST] <cousin_luigi> or perhaps that means that I don't really have the correct resolution?
[17:11:45 CEST] <bencc> is there a filter to fix broken voice in the audio channel?
[17:11:55 CEST] <bencc> to make the speech sound more fluent and not broken
[17:12:09 CEST] <bencc> like opus plc works
[17:55:29 CEST] <tristandm> Hi, so I'm trying to use ffmpeg to stream from YouTube out to a file using the realtime (-re) parameter on the input stream (youtube source url, found with youtube-dl) and partially through the stream the socket disconnects. Any insight? https://pastebin.com/jM1fWN8e
[18:02:10 CEST] <BtbN> download the file first, and use -re on the file then
[18:02:18 CEST] <BtbN> you might just plain timeout the server connection
[19:21:10 CEST] <hiihiii> hello
[19:21:55 CEST] <hiihiii> how would you drop the last frame out of 3. in other words select the first two frames and drop the last?
[19:22:12 CEST] <hiihiii> A B C A B C A B C
[19:22:14 CEST] <hiihiii> then gat
[19:22:22 CEST] <hiihiii> A B A B A B
[19:23:24 CEST] <hiihiii> using fps drops the middle frame
[19:23:27 CEST] <hiihiii> I get
[19:23:34 CEST] <hiihiii> A C A C A C
[19:23:48 CEST] <hiihiii> end that messes with my filters
[19:24:31 CEST] <hiihiii> Can I use select filter?
[19:32:43 CEST] <c_14> don't see why not
[19:51:53 CEST] <faLUCE> (libav) Hello. Is there an EASY way to demux LIVE packets, instead of filling the AVIOContext buffer through the read callback and then call av_read_frame()? This method sounds terrible, and I can't believe that the API doesn't provide an easier mechanism
[20:21:41 CEST] <GNU\colossus> is there an objective way to compare the quality for two different output files that are results of the same input?
[20:25:02 CEST] <furq> yes, but they're not really useful these days
[20:26:18 CEST] <furq> modern video codecs will deliberately do things which reduce psnr/ssim scores
[20:26:23 CEST] <furq> s/codecs/encoders/
[20:29:51 CEST] <roxlu> hey! I just saw that ffmpeg support VideoToolbox based encodding. Does this also work on iOS?
[20:32:11 CEST] <Mandevil> Why I am getting [libx264 @ 00000000005ecb60] DPB size (16 frames, 518400 mbs) > level limit (5 frames, 184320 mbs)
[20:32:22 CEST] <Mandevil> When I am not specifying ref frames?
[20:32:28 CEST] <Mandevil> https://pastebin.com/y2EfdzQG
[20:32:31 CEST] <furq> are you specifying -preset veryslow
[20:32:43 CEST] <furq> good guess furq
[20:32:45 CEST] <Mandevil> And that forces -refs 16?
[20:32:54 CEST] <furq> yeah
[20:33:03 CEST] <Mandevil> But why doesn't x264 just up the level?
[20:33:06 CEST] <furq> i don't know
[20:33:09 CEST] <furq> it should do that
[20:33:14 CEST] <furq> that's always worked for me anyway
[20:33:25 CEST] <Mandevil> Yes, it works when you use x264 directly.
[20:33:31 CEST] <furq> i mean through ffmpeg
[20:33:33 CEST] <ertes> hi& what are the presets i can use with libx264 for someone who doesn't want to learn what all the individual options do?
[20:33:40 CEST] <furq> i always use -preset veryslow and it sets the level automatically
[20:34:14 CEST] <Mandevil> furq: It says it is using level 5.2
[20:34:19 CEST] <Mandevil> That _should_ be sufficient.
[20:34:45 CEST] <furq> ertes: http://vpaste.net/ptWeO
[20:35:07 CEST] <furq> Mandevil: is this 4k
[20:35:15 CEST] <Mandevil> Yes.
[20:35:20 CEST] <Mandevil> 3840x2160
[20:35:40 CEST] <furq> yeah i'm guessing that's just too much for h264 to handle
[20:35:55 CEST] <Mandevil> It's not the first 4k video I am encoding.
[20:36:03 CEST] <Mandevil> Why I haven't seen this before.
[20:36:05 CEST] <furq> wikipedia reckons 2160p60 will only support 5 refs at 5.2
[20:36:10 CEST] <ertes> furq: thanks!
[20:36:14 CEST] <Mandevil> This is 25 fps video.
[20:36:18 CEST] <furq> shrug
[20:36:34 CEST] <furq> actually nvm the framerate obviously won't matter
[20:36:45 CEST] <Mandevil> :)
[20:37:14 CEST] <Mandevil> I was encoding different 4k video recently and haven't noticed the message.
[20:37:20 CEST] <furq> you could maybe try -level 52
[20:37:26 CEST] <furq> forcing level will normally cap refs
[20:37:38 CEST] <GNU\colossus> furq, thanks
[20:37:45 CEST] <furq> i'm surprised libx264 doesn't handle that automatically though
[20:37:53 CEST] <furq> that might be worth a bug report if you're on the latest
[20:39:27 CEST] <Mandevil> *more testing needed
[20:40:12 CEST] <furq> i think it normally handles it by just bumping the level
[20:40:18 CEST] <furq> but obviously it can't do that in this case
[20:40:35 CEST] <Mandevil> But it says it _is_ using 5.2
[20:40:43 CEST] <furq> well yeah but 5.2 is the highest
[20:40:44 CEST] <Mandevil> And 5.2 _is_ enough for 2160p at 25
[20:40:46 CEST] <furq> and that only does 5 refs
[20:41:23 CEST] <furq> i think -level 52 capping refs is done by ffmpeg
[20:41:47 CEST] <Mandevil> I can just specify -refs 5 and be done with it.
[20:41:52 CEST] <furq> yeah that works
[20:42:17 CEST] <Mandevil> I assume most SW decoder will handle that ok anyway?
[20:42:30 CEST] <furq> it's within the spec
[20:42:38 CEST] <furq> i've never really touched 4k x264 though
[20:42:41 CEST] <Mandevil> I mean, refs 16 :-)
[20:42:45 CEST] <furq> oh
[20:42:46 CEST] <furq> no idea then
[20:42:59 CEST] <Mandevil> 4k x265 is unbearably slow on my PC.
[20:43:06 CEST] <furq> i certainly wouldn't expect hardware decoders to touch it
[20:43:51 CEST] <furq> if ffmpeg decodes it ok then most software players will work
[20:44:00 CEST] <furq> all the ones worth using use libavcodec anyway
[20:45:09 CEST] <furq> and yeah x265 is generally unbearably slow
[20:45:48 CEST] <Mandevil> 3 minute 4K video... something like 20 hours encoding on veryslow.
[20:45:59 CEST] <furq> nice
[20:46:19 CEST] <Mandevil> Then again, i5 ivy bridge is not the fastest CPU in the universe.
[20:46:39 CEST] <furq> fwiw -crf 18 is probably overkill with 4k
[20:46:48 CEST] <furq> i doubt it makes too much difference for three minutes though
[20:47:01 CEST] <Mandevil> furq: I don't have much grasp of x265 crf's.
[20:47:06 CEST] <furq> i mean with x264
[20:47:31 CEST] <furq> you can get away with higher crf at higher resolution
[20:47:31 CEST] <Mandevil> 18 is my go to crf for "best quality, bitrate doesn't matter"
[20:47:38 CEST] <furq> fair enough
[20:48:13 CEST] <Mandevil> BTW, I tried encoding with libx265 on 32-thread Xeon.
[20:48:27 CEST] <Mandevil> Surprisingly, the loadavg barely went over 10.
[20:48:45 CEST] <Mandevil> So the encoder was unable to saturate the CPU :-(
[20:49:09 CEST] <Mandevil> (it was 720p source, maybe it had something to do with it).
[20:52:31 CEST] <Mandevil> So I stopped the encode and used refs=5
[20:52:39 CEST] <Mandevil> Now it chose level 5.1
[20:52:48 CEST] <Mandevil> Go figure.
[22:45:59 CEST] <tristandm> @BtbN Is there a way that I can have ffmpeg read from a partial file? The issue i'd be running into if i download the whole file would be files that are large, like people playing 10h youtube videos just for a portion of it. Previously when I tried having ffmpeg use a partial file as an input, it would only read up to the point where the file was at the time ffmpeg started reading from it
[22:47:21 CEST] <tristandm> Like a way to treat the file as a stream input
[23:55:16 CEST] <faLUCE> (libav) Hello. Is there an EASY way to demux LIVE packets, instead of filling the AVIOContext buffer through the read callback and then call av_read_frame()? This method sounds terrible, and I can't believe that the API doesn't provide an easier mechanism
[00:00:00 CEST] --- Mon May 15 2017
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