[Ffmpeg-devel-irc] ffmpeg.log.20171012

[burek]

[00:04:42 CEST] <Johnjay> what's the significance of using 10 bits for HEVC?
[00:05:29 CEST] <durandal_1707> more colors, no banding...
[00:05:31 CEST] <JEEB> 10bit improves compression if nothing else
[00:06:12 CEST] <JEEB> it was already useful in AVC, but unfortunately nothing supported it except for mainconcept's sw decoder (which made playback of 10bit with flash possible, funny enough)
[00:07:42 CEST] <TD-Linux> due to increased transform accuracy, it's less useful for AV1 and VP9
[00:07:46 CEST] <TD-Linux> it still gives you a percent or two
[00:08:05 CEST] <alexpigment> as durandal said, 10-bit gets rid of most visible banding. a lot of people's brains are just trained to accept it, but gradients look AWFUL in all 8-bit video, which is most of the video industry at this point
[00:08:53 CEST] <alexpigment> of course, bandwidth starving 8-bit video doesn't help gradients either, but unfortunately that's the norm
[00:23:54 CEST] <toblorone> Hi this is probably off topic, but someone in the math channel suggested i ask here
[00:23:57 CEST] <toblorone> dumb question: I'm implementing some image processing stuff, and I'd like to filter out a certain frequency band in the time domain. I know I can do this using a convolution, but I'm not sure how i'd go about designing the kernel.
[00:36:42 CEST] <DocHopper> JEEB: Is there a way to sync FFMPEG with the system clock?  That might allow me to get by without needing atomic updates.
[01:17:08 CEST] <DocHopper> Can FFMPEG choose which .txt file to drawtext from based on the .txt's file number?
[01:19:43 CEST] <JEEB> I think at that point I recommend you take a read of drawtext's source code. it's under libavfilter/vf_drawtext.c I guess?
[01:22:20 CEST] <DocHopper> Thanks!
[01:22:41 CEST] <DocHopper> Even just editing drawtext so if the file it is empty it retains the last value, but continues trying to read.
[01:26:06 CEST] <DocHopper> JEEB: Sorry for noob questions, bust that's within ffmpeg?
[01:30:23 CEST] <JEEB> DocHopper: yes
[01:30:31 CEST] <JEEB> FFmpeg consists of multiple libraries
[01:30:53 CEST] <JEEB> ffmpeg.c is just one of the API client tools that come with the code
[01:31:51 CEST] <DocHopper> So I'll need to grab the source code, right?
[01:55:23 CEST] <DocHopper> JEEB: Wow, there is a lot of stuff in FFMPEG!  Looks like it throws at least 2 errors when the file can't be read, and only one comes from vf_drawtext.c
[01:55:53 CEST] <JEEB> DocHopper: yes, yes there is :)
[01:56:05 CEST] <JEEB> the libraries are very far-reaching
[01:56:36 CEST] <DocHopper> JEEB: Any clever methods of tracking down file interactions?
[02:48:29 CEST] <FishPencil> Any ideas why I'm getting this error when compiling FFmpeg with gnutls on macOS? https://paste.ubuntu.com/25723363/
[02:58:29 CEST] <c3r1c3-Win> Not the correct version of GNUtls? Or trying to link to the wrong one?
[02:59:09 CEST] <FishPencil> Is 3.5.15 supported?
[02:59:35 CEST] <c3r1c3-Win> I don't know the answer to that one.
[04:32:31 CEST] <djfk> how to simulate client request different video stream?
[07:12:41 CEST] <nate> Well, that's uh, really nice that firefox no longer warns you when updating that certain plugins won't work anymore
[07:12:56 CEST] <nate> whoop wrong channel lol
[07:13:13 CEST] <nate> was one click off
[14:29:15 CEST] <pankaj_> can anybody help me to compress mp4 videos
[14:29:42 CEST] <pankaj_> i have using
[14:29:42 CEST] <pankaj_> -f mp4 -vcodec h264 -acodec mp2 -threads 4
[14:29:56 CEST] <pankaj_> and -acodec mp2
[14:31:35 CEST] <pankaj_> here is my code https://pastebin.com/d3H1B7RB
[14:36:02 CEST] <ritsuka> what's the problem?
[14:36:11 CEST] <ritsuka> by the way, you should use aac instead of mp2
[14:39:37 CEST] <pankaj_> thanks for reply ritsuka
[14:40:08 CEST] <pankaj_> already try acc
[14:40:29 CEST] <pankaj_> other option
[14:41:33 CEST] <Sharkigator> yeah, but what is the output?
[14:44:43 CEST] <relaxed> pankaj_: https://trac.ffmpeg.org/wiki/Encode/H.264
[14:53:46 CEST] <pankaj_> Sharkigator getting  same size video
[14:54:07 CEST] <Sharkigator> and what do you expect?
[14:55:25 CEST] <pankaj_> small size then real mp4 file
[14:56:31 CEST] <Sharkigator> did you look at the link by relaxed?
[14:56:52 CEST] <pankaj_> yes but not fond any help
[14:57:28 CEST] <pankaj_> can you send me any help full link or any help
[14:57:29 CEST] <pankaj_> ?
[14:57:44 CEST] <Sharkigator> if you want a smaller size, you'll have to choose a slower encoding preset or choose a lower quality
[14:57:57 CEST] <Sharkigator> and it is a full link
[14:59:13 CEST] <Sharkigator> you can for example do -preset slower -crf 27
[14:59:33 CEST] <Sharkigator> the higher the crf, the lower the quality and the smaller the file
[15:10:21 CEST] <pankaj_> Sharkigator not getting help with this
[15:10:40 CEST] <pankaj_> can you send me any example link
[15:10:50 CEST] <Sharkigator> what are you getting?
[15:11:11 CEST] <pankaj_> same file
[15:11:25 CEST] <Sharkigator> does it tell you any error?
[15:11:52 CEST] <pankaj_> no
[15:12:11 CEST] <pankaj_> i' trying with 10,55,736 bytes files size
[15:12:21 CEST] <Sharkigator> did you try using different crf values?
[15:13:01 CEST] <pankaj_> yes superfast,slow
[15:13:30 CEST] <Sharkigator> and what is the log output of ffmpeg?
[15:16:44 CEST] <pankaj_> not check
[15:16:59 CEST] <Sharkigator> ?
[15:16:59 CEST] <pankaj_> how can i check this
[15:17:14 CEST] <Sharkigator> you run it in the commandline?
[15:18:42 CEST] <Sharkigator> or how do you run ffmpeg?
[15:20:51 CEST] <pankaj_> using php file on server
[15:21:24 CEST] <pankaj_> exec("ffmpeg -i input -c:v libx264 -preset fast -crf 22 -c:a output);
[15:21:38 CEST] <Sharkigator> then try it locally first
[15:22:22 CEST] <Sharkigator> or find a way to get the stderr from that process
[15:25:43 CEST] <beauty> hello
[15:26:12 CEST] <beauty> how to play video using ffplay without image and audio
[15:26:20 CEST] <beauty> just simulate process
[15:27:26 CEST] <pankaj_> beauty check this https://www.ostechnix.com/20-ffmpeg-commands-beginners/
[15:28:28 CEST] <beauty> it doesn't have what I need
[15:30:46 CEST] <Sharkigator> can't you run ffmpeg with a null output?
[15:30:49 CEST] <Sharkigator> ffmpeg -i input -f null -
[15:37:49 CEST] <beauty> Sharkigator: I want to simulate player process
[15:38:00 CEST] <Sharkigator> does it not work?
[15:38:09 CEST] <beauty> Using ffmpeg will exit quickly
[15:38:13 CEST] <paveldimow> Hi guys, does anyone can recommend transport protocol that can be used to achieve the lowest latency possible? I know of RTMP, is there anything else supported by FFmpeg?
[15:38:53 CEST] <beauty> For example, a video of 5 min ,using ffplay , it's for 5min,but using ffmpeg few seconds
[15:39:13 CEST] <Sharkigator> you can add the -re flag for that
[15:39:31 CEST] <Sharkigator> then it will decode it at playback speed i think
[15:41:09 CEST] <beauty> Sharkigator: it seems work
[15:41:36 CEST] <Sharkigator> i still don't know why you would want to do that
[15:46:44 CEST] <beauty> I want to simulate multi clients request nginx server.
[15:48:49 CEST] <beauty> Sharkigator: Is there better server stress test tools?
[15:49:03 CEST] <Sharkigator> i don't know
[15:52:44 CEST] <beauty> thanks
[15:56:12 CEST] <redrabbit> you can always give the link
[16:13:09 CEST] <beauty> ffmpeg  -re -i input.mp4 -f null - 2> /dev/null &
[16:13:29 CEST] <beauty> why does this command not work?
[16:14:05 CEST] <JEEB> don't throw away the stderr first of all so you can see?
[16:17:17 CEST] <beauty> JEEB: I can't see, could you show me?
[16:25:25 CEST] <beauty> why ffmpeg process in background running, but cpu usage is 0?
[16:25:31 CEST] <celyr> beauty, ffmpeg  -re -i input.mp4 -f null -
[16:26:28 CEST] <beauty> I want ffmpeg process to be in shell background.
[16:42:18 CEST] <beauty> I have solve it
[16:42:47 CEST] <beauty> so how to make ffmpeg not to decode data?
[16:52:10 CEST] <vbnunes> hello all
[16:52:21 CEST] <relaxed> beauty: use screen/tmux or ffmpeg -i ... 2>log.txt </dev/null &
[16:53:18 CEST] <beauty> thank
[16:53:22 CEST] <beauty> I have solved
[16:53:58 CEST] <vbnunes> I'm trying to stream a STANAG video+data to a tcp port using ffmpeg with a STANAG video on loop, which resets the timestamps to current time
[16:54:59 CEST] <vbnunes> i'm doing this by reading from a playlist but I cannot reset the timestamps
[16:56:53 CEST] <vbnunes> ffmpeg -re -f concat -safe 0 -i playlist.txt -map 0:0 -map 0:2 -c copy -f mpegts tcp://something:1234
[16:57:08 CEST] <vbnunes> can anyone help?
[17:23:55 CEST] <subli> vbnunes: since this place is pretty dead. YOu could try the VLC development channel (also on freenode)
[17:24:10 CEST] <subli> It's very active
[17:24:59 CEST] <subli>  #videolan
[17:36:46 CEST] <vbnunes> thanks subli
[19:23:34 CEST] <doublya> Building ffmpeg against Cuda9.0, getting ERROR: libnpp not found
[19:25:24 CEST] <BtbN> doublya, update your ffmpeg.
[19:25:32 CEST] <doublya> thanks!
[19:26:02 CEST] <BtbN> Isn't that fairly obvious of a solution?
[19:55:52 CEST] <kwizart> hello, any reaction on this https://www.phoronix.com/scan.php?page=news_item&px=Fedora-FDK-AAC ? (will you make fdk-aac free now that fedora(-legal) consider this to be legal item ?
[19:56:15 CEST] Action: kwizart is going to dinner, but will be around for comments later tonight or tommorrow
[19:57:06 CEST] <JEEB> kwizart: IIRC the only problem with fdk-aac was that it was incompatible with (L)GPL and thus you couldn't match it with anything else
[19:57:11 CEST] Action: JEEB goes read
[19:59:15 CEST] <JEEB> kwizart: because debian/ubuntu also distribute fdk-aac but they don't link it against such things specifically
[19:59:28 CEST] <JEEB> gstreamer is a special case because you aren't linking, it's run-time plugin based stuff
[20:05:22 CEST] <BtbN> A lot of distributions distribute fdk-aac, and there is nothing that prevents them, they are not linking to it.
[20:05:35 CEST] <BtbN> But fdk-aac is clearly not L/GPL compatible
[20:05:49 CEST] <JEEB> yes
[20:06:06 CEST] <JEEB> the point of putting A and B together is where the non-distributability comes in
[20:07:43 CEST] <BtbN> I wonder why fdk-aac in fedora is such a big deal. They definitely also ship ffmpeg, which has an aac decoder and also a very decent encoder since recently.
[20:17:25 CEST] <JEEB> BtbN: fedora doesn't shit FFmpeg tho
[20:17:32 CEST] <JEEB> *ship
[20:17:41 CEST] <JEEB> it prefers small chunks of code they can review
[20:17:45 CEST] <JEEB> which doesn't work with FFmpeg
[20:17:56 CEST] <JEEB> even if they disable things the legal team needs to be OK with *all* of the code base
[20:18:06 CEST] <JEEB> which is why FFmpeg getting officially packaged is highly unlikely
[20:18:15 CEST] <JEEB> rpmfusion will of course havei t
[20:20:19 CEST] <BtbN> that sounds highly impracticel
[20:20:28 CEST] <BtbN> So they don't have any popular multimedia software?
[20:20:36 CEST] <BtbN> Or do they just build everything without ffmpeg support?
[20:20:47 CEST] <JEEB> I think VLC isn't packaged, either
[20:20:52 CEST] <JEEB> among other things
[20:21:16 CEST] <JEEB> basically for AC3 they ripped out the AC3 thing from libavcodec I think
[20:21:29 CEST] <JEEB> for MP3 they of course took that old library no longer remembers
[20:21:34 CEST] <JEEB> mp123 was it?
[20:22:00 CEST] <JEEB> I actually asked about just building FFmpeg with components disabled, but they told me that the whole thing would have to be lawyer-OK'd
[20:39:37 CEST] <pxl> Hey! anyone in here know if you can use ffmpeg to get the SPS and PPS for a .ts fragment? Trying to make a tool to generate DASH ISO-BMFF manifests
[20:55:22 CEST] <BtbN> it definitely can. But I'm not sure if there is a public API for it
[20:55:35 CEST] <BtbN> It can just generate DASH for you though.
[21:30:54 CEST] <kerio> wasnt fedora just redhat linux without redhat
[21:39:01 CEST] <JEEB> kerio: no, it's the development branch of red hat
[21:39:16 CEST] <kerio> they must have a big testing team ;o
[21:39:34 CEST] <JEEB> basically fedora is what then becomes with time into RHEL
[21:39:40 CEST] <JEEB> and centos is the RHEL fork
[21:39:48 CEST] <JEEB> which rebuilds all the packages without red hat references
[21:40:44 CEST] <tdr> eh rebuilds them sure, not so much removing all the references
[21:42:12 CEST] <JEEB> https://wiki.centos.org/FAQ/General#head-c52e59ddb12b54379688ce386b0ffafc18669a95
[21:42:51 CEST] <JEEB> basically they remove it where it's required
[21:54:57 CEST] <doublya> building from ffmpeg master branch.  Having a issue with kvazaar: kvazaar/src/threadqueue.c:410: undefined reference to `pthread_join'
[21:57:01 CEST] <DHE> something's gone wrong in your configure script. you can work around with --extra-ldflags=-pthread
[21:57:32 CEST] <JEEB> anyways, kvazaar is not FFmpeg
[21:58:20 CEST] <DHE> ah, it's their internal code doing that and not ffmpeg's
[21:59:28 CEST] <JEEB> yup
[22:06:10 CEST] <doublya> strange. I needed to link -lm  for libmp3lame as well
[22:08:34 CEST] <mulander> anyone else gettin a 504 when trying to register an account on trac?
[22:12:00 CEST] <mulander> nvm, worked on 2nd try
[22:25:52 CEST] <doublya> with ffmpeg master branch, v4l2 is not an enabled indev
[22:27:19 CEST] <doublya> The only thing suspect in the config.log is libv4l2='no'
[22:32:16 CEST] <kepstin> doublya: it's not enabled by default, are you using '--enable-libv4l2' on configure?
[22:34:22 CEST] <doublya> Thanks, must be a change from the older version I was using. I added the flag. Not the linker can't find libv4l2
[22:35:06 CEST] <doublya> I have libv4l-dev package installed
[00:00:00 CEST] --- Fri Oct 13 2017