[Ffmpeg-devel-irc] ffmpeg.log.20190428

Mon Apr 29 03:05:02 EEST 2019

[00:51:09 CEST] <snap1> everybody:   did you know that intel system does not support  high-density ram:  where AMD system does
[01:27:22 CEST] <irwiss> anyone knows if api users can somehow get to the MiscFlags in hwcontext_d3d11va.c without a recompile? I'd like to set shared flag so i can try accessing the texture array from another context, but can't figure out where to grab the knob to tune it or if it's just hardcoded to have no flags https://ffmpeg.org/doxygen/4.1/hwcontext__d3d11va_8c_sourc
[01:27:22 CEST] <irwiss> e.html#l00256
[01:29:20 CEST] <irwiss> welp, botched the link, the flags are set around line 256, i'm wondering if i can somehow change the pointer to d3d11va_frames_init at the bottom to point at my function that'll set the flag
[04:53:36 CEST] <Humanoid> Why doesn't my ffmpeg show the language of the streams?  When I use "ffprobe -show_entries stream_tags" I get nothing.
[05:01:04 CEST] <Humanoid> It happens when I ffprobe a bluray disc.
[05:44:38 CEST] <snap1> if OLED monitor were same price as LCD monitor,  is it better to get  OLED monitor?
[09:43:19 CEST] <Jolein> the mb_size default is 16 but what gives better quality lowering or increasing the value and if so by how much is still obtainable ?
[09:43:29 CEST] <Jolein> for minterpolation
[09:58:58 CEST] <durandal_1707> Jolein: depends on many factors
[09:59:35 CEST] <Jolein> durandal_1707 i am just testing out all the settings available but dont realy understand the mb_size value
[09:59:41 CEST] <Jolein> like what does it do
[10:00:48 CEST] <durandal_1707> Jolein: it is macroblock size in pixels
[10:01:02 CEST] <Jolein> would lower be better or higher ?
[10:01:22 CEST] <Jolein> or is it not realy important?
[10:03:08 CEST] <durandal_1707> how do i know, i dunno with what video you are playing with
[10:03:30 CEST] <Jolein> what do you mean ?
[10:06:19 CEST] <durandal_1707> Jolein: it depends on  input video
[10:07:04 CEST] <Jolein> input video is a 1080p mkv file h.264
[10:08:18 CEST] <durandal_1707> i mean actual PIXELS
[10:10:35 CEST] <Jolein> i apreciate you are tying to help but i dont realy understand what you are asking here
[10:10:44 CEST] <durandal_1707> bigger block size make filtering faster for very high resolution
[10:10:52 CEST] <der_richter> snap1 depends, for a 'short' time it will definitely be better in output quality, till you get burn ins
[10:11:28 CEST] <snap1> ok
[10:11:33 CEST] <durandal_1707> Jolein: when you describe all pixels you see in your video, than i can help you...
[10:12:42 CEST] <Jolein> well the first pixel is black
[10:12:44 CEST] <der_richter> snap1 static content is an OLED killer, and as a computer monitor it would need to show a lot of it
[10:13:13 CEST] <Jolein> the second pixel is #e97b9e
[10:13:34 CEST] <Jolein> the third pixel is #e97b90
[10:13:50 CEST] <durandal_1707> lol
[10:14:00 CEST] <Jolein> :p
[10:14:10 CEST] <Jolein> you want the total pixels per frame ?
[10:15:07 CEST] <durandal_1707> no, you can not explain it in words
[10:15:15 CEST] <Jolein> you want the video ?
[10:16:05 CEST] <durandal_1707> only if it is anime
[10:17:11 CEST] <Jolein> well its not anime
[10:17:19 CEST] <Jolein> its a 9s test clip
[10:17:29 CEST] <Jolein> you can download it straight if you want to
[10:19:44 CEST] <Jolein> well if you have an ftp client
[11:38:52 CEST] <MatthewAllan93> Hey is there anyway in FFMPEG to set the language of the chapters in the output file from the input file?
[15:36:20 CEST] <XLS202> Hey, I have problems using FFMPEG as a restreamer for Twitch. Every time OBS looses a few frames the connection to twitch crashes.. not completly but unwachtable.
[15:38:03 CEST] <BtbN> You'll need to explain your setup more. You are using nginx I assume?
[15:40:50 CEST] <XLS202> Not exactly, i will paste my commands in a pastebin.
[15:42:56 CEST] <XLS202> https://pastebin.com/7p1V74xb
[15:43:15 CEST] <XLS202> I could als provide the log snippet then the problem appears.
[15:43:55 CEST] <BtbN> Use nginx, not the rtmp "server" in ffmpeg.
[15:45:30 CEST] <XLS202> And this would help with such problems?
[15:49:26 CEST] <XLS202> And should i use the rtmp Module from sergey-dryabzhinsky  or from arut?
[15:49:38 CEST] <XLS202> Or do you mean something else
[15:50:03 CEST] <BtbN> There is only one rtmp module for nginx, most distributions even packaged it by now.
[15:52:03 CEST] <XLS202> Okay thank you for your help :) I will look into it.
[16:15:41 CEST] <MatthewAllan93> Hey is there anyway in FFMPEG to set the language of the chapters in the output file from the input file?
[16:58:04 CEST] <GuiToris> hey, I have a little problem. I exported my video into pngs but with alpha channel and I created a video with ffmpeg -i %d.png output.mp4 but because of the alpha channels fade in and out aren't visible. What can I do?
[16:58:13 CEST] <GuiToris> do I have to reexport the video without alpha?
[17:21:55 CEST] <cehoyos> GuiToris: Please use pastebin to show us your command line including complete, uncut console output
[17:26:50 CEST] <MatthewAllan93> Just wondered because I was converting a file that had chapters in it, the language prefix in mediainfo didn't display properly but the chapters were there.
[17:28:05 CEST] <cehoyos> Feel free to post the FFmpeg command line you used together with the complete, uncut console output.
[17:41:07 CEST] <GuiToris> cehoyos, that was the entire command
[17:41:18 CEST] <GuiToris> I didn't use any filters
[17:41:34 CEST] <GuiToris> ffmpeg -i filename_%3d.png output.mp4
[17:41:51 CEST] <pink_mist> GuiToris: you're forgetting the console output. all of it.
[17:42:00 CEST] <pink_mist> please don't paste it in the channel though.
[17:42:02 CEST] <pink_mist> use a paste site
[17:42:06 CEST] <GuiToris> get it
[17:46:28 CEST] <GuiToris> cehoyos, pink_mist https://bpaste.net/show/2657aae62888
[17:47:26 CEST] <GuiToris> I created a fade in but it's not visible here
[17:47:38 CEST] <GuiToris> the png files are transparent there
[17:48:16 CEST] <GuiToris> it's weird because the first image is completely transparent, yet I see the full image here in the video
[17:51:00 CEST] <cehoyos> That's because h264 does not support transparency (and newer FFplay plays a trick on you, implying that there is some "fading" where there is none).
[17:51:21 CEST] <cehoyos> You have to overlay your video over some background of your choice, for example the "color" filter (that defaults to black)
[17:53:34 CEST] <GuiToris> can you tell me the actual code of that filter?
[17:53:50 CEST] <GuiToris> I've never used one, and I wouldn't like to mess this up
[18:01:35 CEST] <de-facto> GuiToris, i am new to ffmpeg, but i think its possible to use chromakey or lumakey (e.g. lumakey=16:4:4 for everything black) to set transparency then use overlay=x=<coord>:y=<coord> to put that on a background video
[18:03:39 CEST] <cehoyos> ffmpeg -i input -vf color[c],[c][0:0]overlay out.mov
[18:05:35 CEST] <cehoyos> ffmpeg -i FULL_%4d.png -t 3 -vf color=s=hd1080[c],[c][0:0]overlay out.mov
[18:06:06 CEST] <cehoyos> As said, the color filter defaults to black, but you can choose any background color
[18:11:05 CEST] <GuiToris> cehoyos, what's the difference between color[c] and color=s=hd1080[c]
[18:16:55 CEST] <GuiToris> cehoyos, the second one works well
[18:16:56 CEST] <cehoyos> color defaults to 320x240 but I think you want 1920x1080
[18:17:21 CEST] <GuiToris> yes, that's what I wanted thank you so much
[18:17:41 CEST] <GuiToris> the first one was really small indeed
[20:28:02 CEST] <hedgehog90> Hi, I've got a RGBA PNG sequence (a 3D animation, 24fps, 9 minutes long) and I want to convert it to h264 (YUV colorspace) so I can upload it to youtube and other video hosting sites. I've done this before many times, but always experience a certain amount of color banding, especially with glowing lights in a dark environment. I've tried sws_dither, the dither filter and the deband filter, I've tried all sorts, but nothing seems to work that well,
[20:28:02 CEST] <hedgehog90> considering I want to preserve the quality of my animation as best as possible (~40mbps). Any guidance on this would be much appreciated!
[20:31:42 CEST] <JEEB> hedgehog90: try encoding losslessly first and seeing if the issue is in the colorspace conversions or not
[20:31:53 CEST] <JEEB> or if it's the lossy compression if that's what you're doing
[20:32:04 CEST] <JEEB> note: youtube does support lossless ingest just fine
[20:32:07 CEST] <furq> try 4:4:4 and 4:2:0 as well
[20:32:14 CEST] <hedgehog90> It's lossless RGB encoded HuffYUV
[20:32:15 CEST] <JEEB> (although of course youtube will derp it up)
[20:33:12 CEST] <hedgehog90> I'm well aware JEEB, but there are other sites with less derpifying video processing  settings.
[20:33:20 CEST] <JEEB> yup
[20:33:24 CEST] <JEEB> thank goodness for that :P
[20:33:26 CEST] <hedgehog90> and i want to get it looking perfect as possible
[20:33:44 CEST] <JEEB> anyways, just noting that you should attempt to limit to one or so scene which you know has your issue
[20:33:51 CEST] <JEEB> and then test encoding losslessly
[20:33:58 CEST] <hedgehog90> Fortunately it's the beginning scene
[20:34:08 CEST] <JEEB> to see if it's the encoding, or the actual colorspace conversion
[20:34:22 CEST] <JEEB> with libx264 you can just set -q:v 0 for lossless
[20:34:27 CEST] <hedgehog90> and yes, encoding with h264 crf 0 produces banding
[20:34:30 CEST] <JEEB> ok
[20:35:17 CEST] <JEEB> I would then compare it to zscale's conversion, which should probably be something like -vf "scale,format=bgrb,zscale,format=yuv420p"
[20:35:24 CEST] <JEEB> I /think/ that works, but I didn't just test it
[20:35:33 CEST] <JEEB> also it requires you to have FFmpeg built with the zimg library
[20:35:36 CEST] <JEEB> https://github.com/sekrit-twc/zimg
[20:35:46 CEST] <hedgehog90> I'll give that a go
[20:36:01 CEST] <JEEB> not sure if the initial scale is needed
[20:36:10 CEST] <JEEB> the format should have auto-insertion there if needed
[20:36:34 CEST] <hedgehog90> Is there a build with zimg that you could provide?
[20:36:36 CEST] <JEEB> also I think format needed pix_fmts parameter
[20:36:42 CEST] <JEEB> nope
[20:36:54 CEST] <JEEB> depending on the OS there might be some people doing it
[20:36:59 CEST] <JEEB> f.ex. I think on windows zeranoe does it?
[20:37:07 CEST] <hedgehog90> windows64 bit
[20:37:31 CEST] <JEEB> note that I do not endorse his builds, but they are some of which people seem to be using
[20:37:40 CEST] <JEEB> https://ffmpeg.zeranoe.com/builds/readme/win64/static/ffmpeg-20190427-8019395-win64-static-readme.txt
[20:37:43 CEST] <JEEB> and it seems to have zimg there
[20:37:51 CEST] <hedgehog90> thanks
[20:38:40 CEST] <JEEB> https://www.ffmpeg.org/ffmpeg-all.html#format-1
[20:38:46 CEST] <JEEB> so yes, the format filter takes in pix_fmts
[20:39:01 CEST] <JEEB> thus it's format=pix_fmts=THING
[20:39:05 CEST] <hedgehog90> -pix_fmt yuv420p ?
[20:39:05 CEST] <JEEB> and not just format=THING
[20:39:19 CEST] <JEEB> hedgehog90: that's probably inserting something similar at the end
[20:39:24 CEST] <JEEB> but I like to have it in the filter chain
[20:39:50 CEST] <hedgehog90> sorry, could you provide it in full commandline terms?
[20:39:53 CEST] <JEEB> -vf "scale,format=pix_fmts=bgrb,zscale,format=pix_fmts=yuv420p"
[20:39:56 CEST] <JEEB> so something like this?
[20:40:02 CEST] <JEEB> not sure if the initial scale is needed
[20:40:07 CEST] <hedgehog90> ok, trying it now
[20:40:28 CEST] <JEEB> also zscale might need you to say that "hey, I want BT.709 output"
[20:41:23 CEST] <hedgehog90> oh - another thing, my lossless video is 24fps according to mediainfo (as it should be) but when I try converting it with ffmpeg or handbrake, I need to specify the framerate because it assumes something wacky like 24.407
[20:41:36 CEST] <JEEB> it shouldn't change the rate
[20:41:43 CEST] <JEEB> you can test this with ffprobe or so
[20:41:48 CEST] <JEEB> unless you add some filters
[20:41:48 CEST] <hedgehog90> Well, right. It's bizarre.
[20:42:19 CEST] <JEEB> anyways, FFmpeg itself doesn't really work with frame rates in general
[20:42:30 CEST] <JEEB> exceptions are just containers that only have a frame rate field like AVI :P
[20:42:41 CEST] <hedgehog90> Could I maybe send you the first few seconds so you can have a look? I think my video editor has produced something that confuses converters somehow
[20:42:41 CEST] <JEEB> although even with that FFmpeg just calculates the DTS/PTS
[20:43:30 CEST] <JEEB> if the thing happens with just that someone could take a look probably
[20:43:44 CEST] <JEEB> at late evening in Sunday my care levels are getting lower by the minute to be honest 8)
[20:43:48 CEST] <JEEB> *on a Sunday
[20:45:33 CEST] <hedgehog90> the file's very big so I've uploaded just the first second: https://drive.google.com/file/d/1nfaqQQlL028oT0N2ruXmcC3T8Q90rf7K/view?usp=sharing
[20:45:58 CEST] <hedgehog90> It comes out as 24.42fps with ffmpeg and other converters
[20:46:16 CEST] <hedgehog90> but mediainfo says 24fps (which it is)
[20:47:52 CEST] <hedgehog90> "Invalid pixel format 'bgrb'"
[20:47:59 CEST] <JEEB> bgrp
[20:48:07 CEST] <JEEB> pretty sure I got that right...
[20:48:08 CEST] <hedgehog90> ah ok
[20:48:32 CEST] <hedgehog90> Invalid pixel format 'bgrp' :)
[20:48:52 CEST] <JEEB> o_O
[20:49:18 CEST] <JEEB> gbrp I guess
[20:49:24 CEST] <JEEB> got it slightly wrong
[20:49:45 CEST] <hedgehog90> code 3074: no path between colorspaces
[20:49:45 CEST] <hedgehog90> Error while filtering: Generic error in an external library
[20:49:58 CEST] <JEEB> ok, so it needs the output definition
[20:50:05 CEST] <JEEB> zscale is fussy because it doesn't want to guess :)
[20:50:41 CEST] <hedgehog90> scale=1920:1080?
[20:51:03 CEST] <JEEB> nah
[20:51:11 CEST] <JEEB> zscale=m=709
[20:51:20 CEST] <JEEB> just add the matrix there, if I recall it correctly
[20:51:29 CEST] <JEEB> either matrix or primaries :)
[20:51:42 CEST] <hedgehog90> ok it's going! :)
[20:52:02 CEST] <JEEB> a lot of systems just expect that if your input/output is HD, you want BT.709
[20:52:07 CEST] <JEEB> and if it's SD you want BT.601
[20:52:22 CEST] <JEEB> zimg is like "no, you *tell* me what you want"
[20:53:55 CEST] <hedgehog90> hmm, honestly can't tell the slightest difference between the 2 :)
[20:55:01 CEST] <hedgehog90> actually no, I see a small improvement tbf
[20:56:51 CEST] <hedgehog90> I spoke too soon, comparing the 2 this is quite a bit better.
[20:56:59 CEST] <hedgehog90> Many thanks :)
[20:57:41 CEST] <hedgehog90> just to make sure, this isn't going to make it any less compatible than if i converted it with more vanilla settings / through handbrake?
[20:57:48 CEST] <JEEB> no
[20:58:01 CEST] <hedgehog90> because some sites kick up a stink if you dont comply to their standards
[20:58:08 CEST] <JEEB> you've just switched the component which is handling the conversion from RGB to YCbCr
[20:58:21 CEST] <JEEB> there's also dithering etc options
[20:58:27 CEST] <JEEB> trying to figure out which is the default :)
[20:59:10 CEST] <JEEB> ah, none
[20:59:15 CEST] <JEEB> which is "round to nearest"
[20:59:32 CEST] <hedgehog90> how would I add dithering then?
[21:00:10 CEST] <JEEB> ":dither=VALUE" at the end of the zscale (filter options are separated with a :)
[21:00:13 CEST] <JEEB> VALUE being one of
[21:00:21 CEST] <JEEB> none,ordered,random,error_diffusion
[21:01:52 CEST] <hedgehog90> which of those would you recommend??
[21:02:07 CEST] <JEEB> I have no idea to be honest :D
[21:02:20 CEST] <hedgehog90> ok, I'll try them out :)
[21:37:04 CEST] <mr_alpaca> if i want to crop a video losslessly, in the command, should "-c:v libx264 -preset veryslow -crf 0 -c:a copy" come before or after the "-filter:v
[21:37:04 CEST] <mr_alpaca>  "crop=1080:608:0:350"" part?
[21:43:50 CEST] <furq> it makes no difference
[21:43:54 CEST] <furq> filtering is always done before encoding
[21:44:43 CEST] <mr_alpaca> i see
[00:00:00 CEST] --- Mon Apr 29 2019