[Ffmpeg-devel-irc] ffmpeg.log.20190928

[burek]

[02:17:29 CEST] <Xatenev> hey
[02:18:37 CEST] <Xatenev> i use ffmpeg with youtube-dl and its loosing metadata in the ffmpeg audio converting from mp4 to wav
[02:18:37 CEST] <Xatenev> theres a command --postprocessor-args that (I assume) directly passes these arguments to ffmpeg
[02:18:37 CEST] <Xatenev> I tried stuff with -map_metadata but I yet havent found any working commands
[02:18:41 CEST] <Xatenev> any ideas what I have to use in there to make it map metadata?
[02:22:18 CEST] <FooNess_> Out of curiosity, why are you going from mp4 to wav? Just to be clear, a lossy format's conversion to wav will not restore it to true lossless form.
[02:23:25 CEST] <Xatenev> FooNess_: dunno, i wanted to prepare a configuration for a friend he said he needed wav.
[02:24:29 CEST] <FooNess_> I see.
[02:25:04 CEST] <Xatenev> converting it to mp3 seems to work fine.
[02:25:10 CEST] <Xatenev> there must be something special with wav.. hm
[02:25:42 CEST] <pink_mist> wav doesn't support metadata as far as I'm aware
[02:26:00 CEST] <Xatenev> ahh
[02:26:21 CEST] <Xatenev> As a derivative of RIFF, WAV files can be tagged with metadata in the INFO chunk
[02:26:22 CEST] <Xatenev> from wikipedia
[02:26:25 CEST] <Xatenev> or is that something else?
[02:26:47 CEST] <FooNess_> That's not true; they actually can embed metadata. It's just that some programs may not be able to read it.
[02:26:48 CEST] <FooNess_> https://en.wikipedia.org/wiki/WAV#Metadata
[02:26:56 CEST] <FooNess_> > Applications may not handle this extra information or may expect to see it in a particular place.
[02:27:03 CEST] <Xatenev> hm
[02:27:05 CEST] <Xatenev> maybe windows can just not read it?
[02:27:13 CEST] <Xatenev> does ffmpeg give me any way to check the metadata?
[02:27:25 CEST] <Xatenev> (I cheecked the metadata with right click => settings )>
[02:27:55 CEST] <pink_mist> guess I'm wrong then
[02:27:58 CEST] <pink_mist> til
[02:28:30 CEST] <Xatenev> ah
[02:28:39 CEST] <Xatenev> ffmpeg -i in.wav -f ffmetadata in.txt shows me metatags
[02:31:28 CEST] <pink_mist> I suppose I must have always used programs that couldn't read the metadata when I dealt with wav
[02:31:41 CEST] <FooNess_> Yeah, it's hit or miss.
[02:31:46 CEST] <Xatenev> thx !:)
[02:31:47 CEST] <Xatenev> all clear then
[06:31:32 CEST] <YellowOnion> What is "Queue input is backwards in time"? why does using a dshow input cause this error?
[06:36:01 CEST] <markfilipak> If I want ffprobe with the largest possible scope, is there an easy call? I tried 'ffprobe -default' per its '-help' advice, but 'ffprobe -default' errored out.
[06:36:23 CEST] <markfilipak> It wanted an argument.
[06:44:29 CEST] <YellowOnion> looks like ffmpeg treats dshow as if i't can play it at any speed...and also ignores -re...wtf
[14:53:51 CEST] <HickHoward> so uhhh
[14:54:18 CEST] <HickHoward> i managed to find a HEVC video that ffmpeg reports as having "unspecified pixel format"
[14:54:32 CEST] <durandal_1707> sample?
[14:54:52 CEST] <HickHoward> hold on
[14:55:04 CEST] <TheAMM> I've ran into some mkvs which claim the same for h264
[14:55:16 CEST] <HickHoward> it's an WWDC 2019 video about "HEVC Video with Alpha"
[14:55:43 CEST] <HickHoward> it's already publicly available but if you want me to send a "sample file" to you i'll try to somewhat manage here
[14:55:44 CEST] <TheAMM> I haven't poked at all of them (I have an automated project that goes through lots of video) but in the few I looked at, it's a case of malformed mkv and ffmpeg failing to resync
[14:55:51 CEST] <cehoyos> HickHoward: This is supposed to play without alpha, please provide the sample
[14:56:30 CEST] <TheAMM> and reports a video stream twice, one proper, then corruption happens and reports the same stream another time but without pixel format etc
[14:56:53 CEST] <cehoyos> You don't have to explain what fails, just provide a lin
[14:56:54 CEST] <cehoyos> k
[14:57:39 CEST] <TheAMM> I'm explaining my experience with ffmpeg's demuxer
[14:58:59 CEST] <HickHoward> https://www.sendspace.com/file/sgixkv
[14:59:20 CEST] <HickHoward> this is the file in question
[14:59:32 CEST] <HickHoward> the "HEVC video" i mentioned earlier
[15:01:03 CEST] <cehoyos> Consider increasing the value for the 'analyzeduration' and 'probesize' options
[15:01:06 CEST] <cehoyos> This works
[15:01:21 CEST] <JEEB> I guess the parameter sets are further down in the file?
[15:02:03 CEST] <cehoyos> But the file was created with FFmpeg and is therefore of very limited usefulness
[15:02:30 CEST] <HickHoward> okay, just hold on
[15:12:09 CEST] <HickHoward> yeah, i just did for that one mp4 file
[15:12:16 CEST] <HickHoward> shows proper info now
[16:01:06 CEST] <n00bV2> Hi peeps!
[16:02:00 CEST] <n00bV2> Is it possible sombody could give me some advice on this:
[16:02:03 CEST] <n00bV2> https://trac.ffmpeg.org/ticket/8208
[16:02:06 CEST] <n00bV2> please :)
[16:09:17 CEST] <BtbN> I'd say bisect it
[16:12:07 CEST] <n00bV2> What the source input?
[16:12:29 CEST] <cehoyos> BtbN:  What do you want to bisect
[16:12:30 CEST] <cehoyos> ?
[16:13:17 CEST] <cehoyos> n00bV2: What kind of advice do you need? The h264 decoder incorrectly returns a failure value in multithreaded decoding, ffmpeg ignored it in the past, prints it now.
[16:14:18 CEST] <n00bV2> The advice I need is; Am I ok to just ignore this failure value or will it cause an issue with encodes?
[16:14:25 CEST] <cehoyos> Did you read the gpl?
[16:14:52 CEST] <BtbN> cehoyos, well, if it workes in 4.1 and doesn't in 4.2, that should be pretty easy to bisect?
[16:15:02 CEST] <cehoyos> Did you look at the ticket?
[16:15:24 CEST] <cehoyos> https://trac.ffmpeg.org/ticket/8208#comment:1
[16:16:25 CEST] <n00bV2> the gpl for ffmpeg?  Probably at one point :p
[16:16:45 CEST] <BtbN> Oh, so it's just more verbose logging, and the failure case was always there?
[16:16:46 CEST] <n00bV2> I did look at the ticket and to the log corrupted packets and frame page
[16:17:20 CEST] <BtbN> Is there any issue beyond it logging that?
[16:17:38 CEST] <cehoyos> You question sounds as if you are asking for some "garantee", you should therefore read the no-warranty clause of the the (l)gpl
[16:17:52 CEST] <cehoyos> Yes, the h264 decoder returns an error on multi-threading
[16:18:16 CEST] <BtbN> But then it can't be the mentioned commit, because it does not add any additional failure cases, just logging
[16:18:18 CEST] <cehoyos> Possibly when PAFF and MBAFF change
[16:18:42 CEST] <cehoyos> That's why I asked what do you want to bisect, I wasn't sure what you meant
[16:18:51 CEST] <cehoyos> s/change/switch
[16:19:54 CEST] <n00bV2> my apologies, wasn't looking for a 100% guarantee. More of a general 'its ok to ignore, it doesn't impact encded output'
[16:20:23 CEST] <cehoyos> As said: The reference decoder does not protest for the given sample (it often does)
[16:20:53 CEST] <cehoyos> In addition, single-threaded decoding for the sample you provided shows no error, another strong indication that there is no issue for the sample you provided.
[16:23:43 CEST] <n00bV2> ok. I think I've got the gist of what you're trying to say :)
[16:26:03 CEST] <cehoyos> n00bV2: Sorry if you don't find the answers helpful, FFmpeg is not a stream analyzer (on the contraray, it is supposed to work fine for broken samples) and I am not convinced the reference decoder is considered a stream analyzer (stream analyzers are typically expensive). The fact that you provided one sample for which a particular warning message is wrong is no proof that the message is always wrong (I suspect this was your original
[16:26:04 CEST] <cehoyos> question).
[16:27:09 CEST] <n00bV2> not at all, I'm happy for the help I've had for you & the other people!
[16:28:16 CEST] <n00bV2> And I think you're right, about that being kinda being my original question.
[16:29:47 CEST] <n00bV2> But I do appreciate the help.  even if I don't always understand it :)
[17:53:22 CEST] <hedgehog90> Hi, I'm downsampling some videos to save space on my harddrive, but I notice that when I convert an mkv (to a lower quality mkv), the video bitrate according to mediainfo is not changing, even though the bitrate is 10% of what it was. How do I tell FFMpeg to write the correct metadata after conversion?
[17:57:24 CEST] <hedgehog90> Anyone? I can't find any information about this online.
[18:13:25 CEST] <n00bV2> hedgehog90: post the command line you're using
[18:13:53 CEST] <hedgehog90> simply any command where the input and output are an mkv
[18:14:10 CEST] <hedgehog90> so 'ffmpeg -i input.mkv output.mkv'
[18:20:47 CEST] <n00bV2> i just did a quick test. input 57.3MB output 41.3MB
[18:21:06 CEST] <n00bV2> Bit rate :
[18:21:08 CEST] <n00bV2> 7 176 kb/s
[18:21:22 CEST] <n00bV2> Bit rate :
[18:21:24 CEST] <n00bV2> 5 327 kb/s
[18:21:50 CEST] <n00bV2> seems to work my end :/
[18:24:01 CEST] <hedgehog90> Is that bit rate value according to mediainfo?
[18:24:27 CEST] <n00bV2> MediaInfoLib - v18.03.1
[18:25:06 CEST] <hedgehog90> Mine's 19.07
[18:25:27 CEST] <hedgehog90> how odd
[18:25:50 CEST] <n00bV2> you could try 18.03.  Maybe do a complete console ouput. but don't paste here
[18:25:58 CEST] <n00bV2> paste it on pastbin or something and put the link here
[18:27:50 CEST] <hedgehog90> interesting, 18.03 displays the correct value
[18:28:34 CEST] <n00bV2> so problem solved....sorta :p
[18:29:20 CEST] <hedgehog90> yeah, 'sorta' :)
[18:32:42 CEST] <furq> hedgehog90: mediainfo reads the mkvtoolnix NUMBER_OF_BYTES/DURATION/BPS tags
[18:32:48 CEST] <furq> and ffmpeg just copies those across blindly
[18:33:16 CEST] <furq> you can either unset those one by one with -metadata, use -map_metadata -1 to nuke all the metadata, or remux it with mkvtoolnix to write the correct values
[18:34:05 CEST] <furq> i don't think ffmpeg will ever write those tags itself but maybe i'm wrong
[18:34:25 CEST] <hedgehog90> Thanks, I should be able to remove those troublesome tags without remuxing though :)
[18:34:47 CEST] <furq> yeah if you just want to fix one file then mkvpropedit or whatever willd o it
[18:35:11 CEST] <furq> i don't think those are defined by any spec, it's some mkvmerge specific thing
[18:35:27 CEST] <JEEB> yea, tags are just freeform text
[18:36:10 CEST] <furq> i always just use mkvmerge --disable-track-statistics-tags
[18:36:15 CEST] <furq> but other people aren't so kind
[20:12:38 CEST] <Thomas_J> I am trying to compile ffmpeg-4.2.1. I am getting Unknown option "--enable-libasound". I have libasound-dev installed. I know it must be something stupid that I've done.
[20:12:50 CEST] <Thomas_J> ./configure --prefix=/usr --pkg-config-flags="--static" --extra-libs="-lpthread -lm" --bindir="./bin" --enable-gpl --enable-version3 --enable-nonfree --logfile=/var/log/ffmpeg/build.log --enable-libasound --enable-libmp3lame --enable-libfdk-aac --disable-doc --disable-htmlpages --disable-podpages --disable-txtpages --enable-libx264 --enable-libx265 --enable-gnutls --enable-static --disable-stripping
[20:13:27 CEST] <pink_mist> the error message is saying that's not a flag that ffmpeg's configure recognises
[20:13:37 CEST] <pink_mist> it's not saying anything about whether it's installed or not
[20:14:00 CEST] <DHE> is that just alsa?
[20:14:03 CEST] <pink_mist> did you see that flag mentioned in ./configure --help?
[20:14:46 CEST] <Thomas_J> I realize that but it has been a working flag before. I am using Alsa.
[20:15:19 CEST] <pink_mist> well it may not be a working flag anymore
[20:15:33 CEST] <pink_mist> (it clearly isn't, in fact)
[20:16:54 CEST] <furq> yeah there is no flag for alsa
[20:17:03 CEST] <furq> it's autodetected
[20:17:10 CEST] <furq> you can only disable it
[20:18:11 CEST] <Celmor[m]> how do I properly transcode HDR content from HEVC to h264, cause if I try to without taking precautions I get "colorless"
[20:18:14 CEST] <Celmor[m]> output*
[20:19:38 CEST] <Thomas_J> I see that now. Alsa recognition must be built in now.
[20:20:16 CEST] <Thomas_J> Thanks
[20:24:33 CEST] <cehoyos> Thomas_J: There was never a configure option --enable-libasound in FFmpeg.
[20:26:40 CEST] <cehoyos> From a quick look, alsa is auto-detected for more than a decade
[20:32:56 CEST] <kepstin> Celmor[m]: to convert from hdr to sdr, you need to apply tonemapping. ffmpeg does have a tonemap filter but i haven't personally used it.
[20:33:18 CEST] <JEEB> kepstin: I was going to respond to him but then I wasn't sure what exactly he wanted to be done :)
[20:33:24 CEST] <JEEB> just 10bit HEVC to 10bit AVC as-is
[20:33:27 CEST] <kepstin> Celmor[m]: otherwise, it might be possible to get the hdr metadata correct in the output file so the player can tonemap if needed
[20:33:34 CEST] <JEEB> or 10bit HEVC tone mapped to 8bit AVC
[20:33:43 CEST] <Thomas_J> Boy! I am really confused now. I went back through the config strings used previously that I have saved not finding it. I ahve no idea how it got into my current config string???
[20:34:17 CEST] <JEEB> the tonemap filter works, but I think unfortunately the opencl one has the latest algorithm
[20:34:20 CEST] <JEEB> (from mpv)
[20:34:21 CEST] <Celmor[m]> I don't care about keeping HDR, I just want to look the color to look the same on a non-HDR display
[20:34:34 CEST] <JEEB> although that as well I think at this point is outdated
[20:35:02 CEST] <JEEB> Celmor[m]: so tone mapped to 8bit BT.709 and gamma
[20:35:28 CEST] <JEEB> that is unfortunately not specified as a standard so every application or module has a slightly different take on it
[20:35:41 CEST] <Celmor[m]> how do I use the tone map filter then? can't finde "tone" in the man page
[20:35:46 CEST] <JEEB> Celmor[m]: https://www.ffmpeg.org/ffmpeg-all.html#tonemap-1
[20:35:50 CEST] <JEEB> it is there, even with an example
[20:35:58 CEST] <JEEB> although yes, it requires you to build FFmpeg with the zimg library
[20:36:04 CEST] <JEEB> https://github.com/sekrit-twc/zimg
[20:36:31 CEST] <JEEB> that enables the zscale filter which is needed for the conversion to linear float and from BT.2020|PQ to BT.709|gamma
[20:36:55 CEST] <JEEB> after that, the example listed should work
[20:37:07 CEST] <cehoyos> How do I use tonemap without an external library? Or is that impossible?
[20:37:25 CEST] <JEEB> I don't think anything else can convert to linear float RGB
[20:37:47 CEST] <cehoyos> How was linear float acceptable...?
[20:38:04 CEST] <JEEB> because the feature was needed but nobody wanted to touch swscale?
[20:38:36 CEST] <JEEB> note: I don't like it, but unfortunately many people Just Use Zimg
[20:38:40 CEST] <JEEB> me included :P
[20:38:40 CEST] <cehoyos> No, I just saw it: It was a late try to damage the project;-)
[20:38:50 CEST] <cehoyos> Too late;-)
[20:39:41 CEST] <JEEB> but yea, I'd almost replace the common code for various things in swscale with zimg
[20:40:03 CEST] <JEEB> it's the edge cases which only swscale will probably support (like paletted formats?)
[20:40:19 CEST] <JEEB> or the general task of packing and unpacking formats
[20:41:13 CEST] <cehoyos> tonemap_opencl seems to work on (nearly) "normal" pix_fmts
[20:41:28 CEST] <JEEB> yea it might include the linearization there?
[20:41:39 CEST] <JEEB> linearization+float
[20:41:40 CEST] <cehoyos> And judging from the commit messages, it may have an additional feature
[20:42:07 CEST] <JEEB> yea, niklas basically had words with him so it probably is closer to what was in mpv and libplacebo
[20:42:11 CEST] <JEEB> although both probably have changed since
[20:42:12 CEST] <Celmor[m]> how do you build FFmpeg with the zimg library? there's not an AUR package or similar by any chance?
[20:42:32 CEST] <JEEB> Celmor[m]: probably packaged by arch I would guess? also you should check if the standard package does that?
[20:42:37 CEST] <furq> does zimg still segfault if you crop a non-mod16 amount off the left hand side
[20:42:47 CEST] <furq> or zscale rather
[20:42:57 CEST] <JEEB> probably. zimg defines requirements for alignment
[20:43:10 CEST] <furq> nice
[20:43:12 CEST] <JEEB> that said, I think some internal filters will barf at that too
[20:43:30 CEST] <JEEB> if you crop so that your lines no longer start aligned
[20:43:57 CEST] <JEEB> because f.ex. the crop filter will attempt to not re-allocate buffers
[20:43:58 CEST] <cehoyos> Yes, a warning should be printed
[20:44:19 CEST] <furq> yeah that'd be nice
[20:44:28 CEST] <furq> it took me longer than i'd have liked to realise i can crop,copy,zscale
[20:48:23 CEST] <JEEB> let me see if there's a function or define to figure out the alignment
[20:48:30 CEST] <JEEB> *required alignment
[20:50:20 CEST] <JEEB> apparently if you're using 64 bit instructions it's 64, otherwise 32
[20:50:53 CEST] <JEEB> or is that byte :P
[20:51:11 CEST] <JEEB> yes, bytes since AVX512 is what's discussed
[20:51:15 CEST] <JEEB> 512 bits, 64 bytes
[20:53:18 CEST] <Celmor[m]> I guess there's no ffmpeg with builtin z.lib packaged/ I can install z.lib itself but dunno how to build with/include it in ffmpeg
[20:56:03 CEST] <cehoyos> johanvansickle indicates zimg...
[20:56:18 CEST] <JEEB> make sure its .pc file is available to FFmpeg's configure and --enable-libzimg is the general gist
[20:58:32 CEST] <cehoyos> The only static binary that I know of contains zimg
[21:02:44 CEST] <JEEB> yea, I think he meant in arch
[21:02:48 CEST] <JEEB> although I'm surprised
[21:02:52 CEST] <JEEB> they usually package a lot of stuff
[21:03:09 CEST] <JEEB> https://www.archlinux.org/packages/community/x86_64/zimg/
[21:03:10 CEST] <JEEB> yea
[21:03:26 CEST] <JEEB> they seem to have added it for vapoursynth, which also utilizes it
[21:04:29 CEST] <JEEB> so their FFmpeg isn't using it, but it's packaged alright
[21:13:31 CEST] <furq> there are definitely some aur packages with zimg
[21:13:36 CEST] <furq> ffmpeg-full obviously has it
[21:14:17 CEST] <JEEB> aye
[21:14:36 CEST] <Thomas_J> "ERROR: gnutls not found using pkg-config". I had this the last time I compiled with gnutls about 2 months ago and cant remember exactly how I fixed it. I think I linked the directory the gnutls.pc file was in to where pkg-config was looking but I can't remember where that is. I have gnutls.pc in "/usr/lib/aarch64-linux-gnu/pkgconfig/gnutls.pc"
[21:15:34 CEST] <JEEB> if you're buildnig yourself, just set PKG_CONFIG_PATH=/usr/lib/YOUR_ARCH/pkgconfig/
[21:15:45 CEST] <JEEB> that appends
[21:15:49 CEST] <JEEB> doesn't overwrite :)
[21:16:25 CEST] <Thomas_J> That's what I've been looking for! Thanks.
[21:27:54 CEST] <Thomas_J> I kinda remember now. it's gnutls looking for missing libs that aren't installed
[21:28:46 CEST] <JEEB> :)
[21:30:17 CEST] <Thomas_J> SUCESS! installed libunistring-dev and worked.
[23:12:19 CEST] <Thomas_J> JEEB; Just a note, the ffmpeg binaries floating around in the debian repositories still haven't been updated yet to fix the problem of streaming rtmps to facebook.
[23:12:52 CEST] <Thomas_J> My new compile is working.
[23:13:00 CEST] <JEEB> right
[23:13:23 CEST] <JEEB> I think I was trying to figure out which branches to back-port the patch and never did that
[23:17:03 CEST] <Thomas_J> I am running ubuntu-server for Arm64. The version in that repo still drops the stream after connecting.
[23:40:46 CEST] <cehoyos> Please do not back-port patches that do not fix a regression or a security issue.
[23:48:06 CEST] <BtbN> Hm? Patches that fix bugs that aren't regressions are backported all the time.
[23:59:36 CEST] <Thomas_J> I can see cehoyos' point. If someone added an update that fixed a security issue but created an issue with rtmps not working..., but is this really what happened?
[00:00:00 CEST] --- Sun Sep 29 2019