[Ffmpeg-devel-irc] ffmpeg.log.20171216

[burek]

[06:27:20 CET] <WireCat> which is the correct current example of demuxing and decoding video? i tried some on google and such they say '..is deprecated' and other stuff.
[06:28:52 CET] <WireCat> i am trying to use the libraries.
[09:07:20 CET] <Stadtpirat> interlace
[09:07:23 CET] <Stadtpirat> oops
[09:53:37 CET] <TheRock2> guys why did ffmpeg not built a player like vlc with its great backend
[10:22:50 CET] <durandal_1707> TheRock2: because of people like you
[10:35:35 CET] <TheRock2> what does that mean
[10:47:25 CET] <durandal_1707> TheRock2: it means you havent sent patch
[10:58:43 CET] <johnnny22> Hi
[11:09:37 CET] <durandal_1707> hi
[11:55:10 CET] <johnnny22> I have a custom pulseaudio sink called 'combined' which is setup to have 8 channels to which I'm playing out a 7.1 audio. I'd like to capture that audio as 8 channels from the pulseaudio but for some reason it isn't working  :o/   Any ideas how to do this ?
[11:57:25 CET] <johnnny22> The sink is called 'combined' and the associated source to it is called 'combined.monitor'
[16:53:24 CET] <adgtl> Network Traffic: [en0]: 2.56 GB in, 169.7 MB out
[16:53:39 CET] <adgtl> Display Resolution: #1: 2560 x 1600
[16:53:50 CET] <adgtl> System Uptime: 1 hour, 38 minutes, 12 seconds - Textual Uptime: 2 minutes, 6 seconds
[16:54:21 CET] <adgtl> I am in 10 channels while connected to 1 network. I have no power whatsoever.
[16:55:49 CET] <saste> hey, can you tell me when I can find the latest SPI treasurer reports? They used to be sent by email, but they are not anymore, apparently
[16:56:10 CET] <saste> ops sorry, wrong chat :-)
[17:55:30 CET] <Guest25576> I'm recording an OpenGL animation with the following command:
[17:55:31 CET] <Guest25576> apitrace dump-images -o - solid.trace | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec h264 -y -crf 22 solid.h264
[17:55:44 CET] <Guest25576> but the playback is really choppy, can I get better fps?
[17:56:32 CET] <sfan5> sounds like a limitation of apitrace
[17:58:04 CET] <sfan5> maybe apitrace can output frames with higher fps, but in any case you should be doing opengl capture directly in realtime; not indirectly through apitrace
[17:58:49 CET] <Guest25576> actually apitrace has a function to replay the .trace file and when I do it plays at the correct fps.
[18:02:35 CET] <Guest25576> ok, how do I capture directly in realtime then?
[18:30:14 CET] <sfan5> mikeglaz: x11grab probably
[18:53:13 CET] <sarah-cal> Hello FFMPEG gurus. I am trying to take an MXF file that has 8 mono tracks (making a 7.1 surround sound audio), and exporting a single surround audio track. Is that possible? I couldn't find a same example in the docs at https://trac.ffmpeg.org/wiki/AudioChannelManipulation.
[18:54:34 CET] <sfan5> http://ffmpeg.org/ffmpeg-filters.html#channelmap should help
[18:55:12 CET] <JEEB> sarah-cal: yes, it's possible with FFmpeg's libraries as well as ffmpeg.c which is the command line tool utilizing various features of the libraries
[18:55:34 CET] <sarah-cal> Ah yes, thats very helpful. Thank you both sfan and Jeeb.
[18:56:12 CET] <JEEB> sarah-cal: the 6x mono -> 5.1 example in the wiki page you linked is relevant to you
[18:56:34 CET] <JEEB> in your case it's of course 8 -> 7.1 but that doesn't change too much
[18:56:52 CET] <JEEB> and instead of multiple inputs you have multiple tracks
[18:57:21 CET] <JEEB> not sure if you can do it with just [0:a], might have to add up [0:a:0] to [0:a:7]
[18:57:48 CET] <JEEB> (audio tracks from 0th to 7th)
[18:57:59 CET] <sarah-cal> Right, I think I understand.
[19:00:37 CET] <JEEB> the problem with such files that there as far as I know is no metadata regarding what's actually contained in them
[19:00:41 CET] <sarah-cal> So the map command can take separate tracks and combine into a single surround track? As in it's not just to fix incorrectly identified channels in a single track?
[19:00:56 CET] <sarah-cal> That makes sense Jeeb.
[19:01:14 CET] <JEEB> map just maps input tracks to output tracks. the filter I thought you'd be looking at was amerge
[19:01:23 CET] <JEEB> which makes a single track out of multiple input tracks
[19:01:44 CET] <JEEB> and then you map the output of that filter chain as a thing that you want to take as input
[19:02:07 CET] <sarah-cal> Ah ok, so it's 2 steps, extracting the individual tracks, then merging them?
[19:03:24 CET] <JEEB> so you have your input -i INPUT (which is the 0th input file), then you have your "complex" filter chain with the tracks from that 0th input file as inputs, fed to amerge which then outputs a single track with the channels merged there (Without mixing). and then you pick that output of the filter chain as what you want to have included in your output
[19:03:28 CET] <sarah-cal> Or do you mean this from the docs? http://ffmpeg.org/ffmpeg-filters.html#Examples-7
[19:04:10 CET] <JEEB> yes, that amerge thing would work as well, except it explicitly tells to convert that audio to format 16bit PCM, signed and little endian
[19:05:09 CET] <sarah-cal> Excellent, thank you so much for the wise tips.
[19:05:10 CET] <JEEB> basically that example is the same as the one on that wiki page about merging 6 channels from separate files to a single track in a single file
[19:05:41 CET] <sarah-cal> I see, thank you Jeeb.
[19:05:42 CET] <JEEB> except as you can see there's only a single input so all of the inputs for the "complex" filter chain are starting with [0:..
[19:06:03 CET] <JEEB> but yea, what I was trying to say is that due to there being no metadata there can always be "fun" situations :P
[19:06:14 CET] <JEEB> f.ex. all of the 8 track MXF files I got had only 2ch used
[19:06:16 CET] <JEEB> for stereo
[19:06:21 CET] <sarah-cal> Yeah, that sounds right for this instance, where the mxf has 9 tracks (1 video, 8 audio mono)
[19:06:42 CET] <JEEB> and then I had other MXF files with one audio stream with 8 channels
[19:06:48 CET] <JEEB> which also only utilized two of them
[19:07:05 CET] <JEEB> so yea, "MXF" is "fun"
[19:07:25 CET] <sarah-cal> Ha! Yes, I'm rapidly understanding that. Thanks agin :)
[20:35:16 CET] <Xorg> guys what does ffmpeg -f ffm mean
[20:36:08 CET] <sfan5> treat the input file as a FFM (FFserver live feed)
[20:40:35 CET] <Xorg> interesting
[21:04:59 CET] <Stadtpirat> Hey, guys, I want to denoise Lawrence of Arabia. It has a lot of noise. I was told that Vapoursynth is good with that stuff. I looked on the website and it lists a lot of denoise plugins. http://www.vapoursynth.com/doc/pluginlist.html
[21:05:11 CET] <Stadtpirat> I don't even know what to pick. Is there a recommendation ?
[21:05:44 CET] <Stadtpirat> I'm new to any of this, so it should be one that doesn#t require a lot of knowledge
[21:07:20 CET] <atomnuker> use the nlmeans filter, vs sucks
[21:15:03 CET] <durandal_1707> nlmeans filter in lavfi is very slow and strange
[21:15:15 CET] <furq> vs has knlmeans (opencl) which works pretty well
[21:15:29 CET] <durandal_1707> Stadtpirat: it all depends on kind of noise
[21:15:38 CET] <furq> but yeah there are a million denoise filters for a reason
[21:39:24 CET] <Johnjay> is dash similar to mp2t?
[21:39:36 CET] <Johnjay> i'm trying to download this vid and i dont' see an mp4 link in the web console
[21:40:07 CET] <Johnjay> http://sfdebris.com/videos/startrek/d403.php
[21:40:36 CET] <Johnjay> my video download extension is reporting 3 or maybe 6 download links to DASH video
[21:41:18 CET] <Stadtpirat> I have some samples of the film here: https://drive.google.com/open?id=1VKp_IwNtV7DTaTlqXkqQkpvFpOF6EDlx
[21:44:36 CET] <Stadtpirat> Could you have a look and tell me, what kind of noise that would be?
[21:46:34 CET] <sfan5> I have no clue but i'm just going to say it's typical (fine) film grain
[21:52:16 CET] <fella> 'a lot of noise' - yeah, almost unwatchable ;)
[00:00:00 CET] --- Sun Dec 17 2017