[Ffmpeg-devel-irc] ffmpeg.log.20170524

burek burek021 at gmail.com
Thu May 25 03:05:01 EEST 2017

[00:09:52 CEST] <asmand> And finally I find some information, it seems that there is an issue in VLC actually: https://trac.videolan.org/vlc/ticket/14577
[01:18:42 CEST] <x86iac> any one know a bit more of this subtitle vulnerability - how does a text file (srt) cause anything?
[01:29:02 CEST] <x86iac> to embarrassed?
[01:59:59 CEST] <marquisor> hi
[07:50:06 CEST] <buu> So, uh, how do I send commands to a running ffmpeg that is streaming output?
[07:50:14 CEST] <buu> Specifically stop/start etc
[12:42:57 CEST] <anchi> Hello, I want to know how can I hold the last frame of the video for 10 more seconds?
[12:58:39 CEST] <SolidusAbi> Hi, can someone help me with smooth streaming? Im trying to use it but when i try to play the player say me "cannot find prueba.ism/Manifest"
[13:00:45 CEST] <SolidusAbi> i used the ismindex tool
[13:36:23 CEST] <chriss4349347293> Hi everyone, I'm searching for help with ffmpeg:
[13:37:24 CEST] <chriss4349347293> I have a url to an jpeg image and I want ffmpeg to query it every second and make video out of it.
[13:37:41 CEST] <chriss4349347293> what I tried:
[13:38:01 CEST] <chriss4349347293> ffmpeg -hide_banner -loop 1 -analyzeduration 0 -r 1 -i "{url}" -an -copyts -f mp4 capture.mp4
[13:38:16 CEST] <colde> I doubt you will get ffmpeg to query it
[13:38:23 CEST] <colde> you would likely have to query and download it yourself
[13:38:24 CEST] <chriss4349347293> ah, ok
[13:38:28 CEST] <colde> and then pipe that sequence into ffmpeg
[13:38:29 CEST] <colde> iirc
[13:38:32 CEST] <BtbN> while true; do curl ...; sleep 1; done | ffmpeg -f image2pipe -i - ...
[13:38:41 CEST] <colde> or something like that
[13:39:07 CEST] <chriss4349347293> ok, that would have been my next idea. just wanted to know, if ffmpeg can do by itself
[13:39:17 CEST] <chriss4349347293> will give it a try with pipe
[13:39:19 CEST] <colde> Not that I am aware of
[13:49:32 CEST] <chriss4349347293> @colde, @BrbN : piping works!! thx for help
[15:48:19 CEST] <mindw0rk> Hi everyone, I'm starting to use libav with the goal of grabbing a single frame from a live hls feed. Thought I ran into a problem that I can't get out of.
[15:48:53 CEST] <mindw0rk> using avformat_open_input comes back with a "Invalid data found when processing input
[15:54:17 CEST] <mindw0rk> "ffmpeg -i (same m3u8 url) -f image2 -vframes 1 snapshot.png" work great on the other hand.
[15:57:59 CEST] <marquisor> i'm looking for a solution to just forward a DVB HD .ts (MP4, AC3) to a server (relay) and leave it as is (copy) to provide it for multiple clients. i read in bugreports ffserver is obsolete? and the copy (passthrough) is not supported at all? so what can i do in my scenario?
[17:07:37 CEST] <mindw0rk> derp, nevermind. I forgot to call av_register_all
[17:07:49 CEST] <SolidusAbi> Can someone help me with ismv example in ffmpeg?
[17:08:02 CEST] <SolidusAbi> im trying to create a ism but it always fail
[19:10:54 CEST] <Thomas> Hello :)
[19:11:12 CEST] <Guest22458> I have a quick question about ffmpeg and hardware acceleration
[19:11:59 CEST] <Guest22458> I compiled ffmpeg with options : --enable-gpl --enable-libx264 --enable-mmal --enable-omx-rpi --enable-omx --enable-nonfree --enable-libxcb
[19:12:22 CEST] <Guest22458> So I can use h264_omx for hardware accelerated encoding
[19:13:15 CEST] <Guest22458> There is no problem during compilation or execution, but I cannot see any difference in terms of performance between using standard x264 encoding (software) and supposedly-hardware-accelerated h264_omx.
[19:14:15 CEST] <Guest22458> As my final objective is to use hardware acceleration to lighten CPU usage, can you help me please ? I use a raspberry pi zero
[19:15:00 CEST] <furq> what's the command you're running
[19:16:00 CEST] <Guest22458> ffmpeg -thread_queue_size 512 -f x11grab -vsync 0 -s 640x360 -r 2 -i :0.0+0,0 -thread_queue_size 512 -f alsa -async 1 -thread_queue_size 512 -ac 2 -channel_layout stereo -i pulse -ab 180k -c:v h264_omx -b:v 500k -bufsize 4000k -c:a aac -strict experimental -b:a 32k -ar 44100 -ac 2 -f flv rtmp://live.twitch.tv/app/
[19:16:09 CEST] <Guest22458> (Of course I deleted my Twitch key)
[19:16:22 CEST] <furq> yeah you're probably cpu bound from doing the pixel format conversion and encoding aac
[19:16:47 CEST] <Guest22458> oh :(
[19:16:47 CEST] <JEEB> yup, armv6 and aac encoding is slow as beep
[19:16:55 CEST] <JEEB> like, almost anything CPU intensive
[19:16:56 CEST] <JEEB> will die
[19:17:17 CEST] <JEEB> also what in that config requires nonfree?
[19:17:38 CEST] <JEEB> omx-rpi?
[19:17:40 CEST] <furq> nothing
[19:17:43 CEST] <JEEB> yea
[19:17:46 CEST] <JEEB> kind of wondered
[19:17:49 CEST] <Guest22458> just added it in-case
[19:17:52 CEST] <JEEB> lol
[19:17:56 CEST] <Guest22458> :p
[19:18:05 CEST] <JEEB> it's only needed for very specific libraries
[19:18:10 CEST] <JEEB> not 1st party code
[19:18:18 CEST] <Guest22458> Maybe I can disable sound and make an other test
[19:18:19 CEST] <furq> fwiw you should see a massive difference between omx and x264 for that particular command
[19:18:56 CEST] <kepstin> particularly on the pi zero, which is only signle core
[19:18:57 CEST] <JEEB> also don't scale
[19:19:10 CEST] <JEEB> also x11grab?
[19:19:13 CEST] <Guest22458> ok
[19:19:15 CEST] <JEEB> is that fast enough by itself?
[19:19:24 CEST] <furq> he's not scaling, that's an input option
[19:19:30 CEST] <JEEB> ...
[19:19:31 CEST] <JEEB> fuck
[19:19:34 CEST] <Guest22458> I need to record a window, and don't know any other input method
[19:19:37 CEST] <furq> actually what does that do with x11grab
[19:19:46 CEST] <JEEB> I mean, I know that it means size
[19:19:53 CEST] <JEEB> but it is linked to vf scale
[19:19:56 CEST] <JEEB> afetr -i
[19:20:22 CEST] <kepstin> I think ffmpeg cli has some magic mapping so -s goes to the -video_size option on inputs?
[19:20:31 CEST] <kepstin> i don't recall exactly.
[19:20:36 CEST] <furq> well yeah but what does that do with x11grab
[19:20:36 CEST] <JEEB> Guest22458: well first of all see how fast just the input and after -i you just put -f null afterwards
[19:20:49 CEST] <JEEB> input options -i input -f null -
[19:20:54 CEST] <furq> i assume something is having to scale it
[19:20:58 CEST] <kepstin> well, x11grab accepts a size for the capture area with the -video_size avoption
[19:21:08 CEST] <furq> oh right
[19:21:09 CEST] <furq> nvm then
[19:21:17 CEST] <marquisor> anyone with -acodec copy -vcodec copy passthrough ffserver?
[19:22:05 CEST] <furq> i don't think there's anyone with ffserver
[19:22:15 CEST] <marquisor> :<
[19:22:19 CEST] <Guest22458> JEEB : ok
[19:22:44 CEST] <marquisor> furq: alternatives to ffserver accepting ffmpeg input?
[19:22:57 CEST] <furq> for what use case
[19:23:18 CEST] <marquisor> i repeat:
[19:23:22 CEST] <marquisor> i'm looking for a solution to just forward a DVB HD .ts (MP4, AC3) to a server (relay) and leave it as is (copy) to provide it for multiple clients. i read in bugreports ffserver is obsolete? and the copy (passthrough) is not supported at all? so what can i do in my scenario?
[19:23:45 CEST] <furq> oh
[19:23:50 CEST] <furq> shame it's ac-3 or you could just use rtmp
[19:24:05 CEST] <furq> that's the only relatively painless streaming setup i know about
[19:24:14 CEST] <marquisor> something like ffmpeg -i http://ip:port/stream.ts -acodec copy -vcodec copy http://server:port/feed.ffm
[19:24:33 CEST] <furq> if you don't mind encoding the audio then rtmp is easy
[19:24:41 CEST] <furq> as long as by mp4 you mean h264
[19:24:46 CEST] <marquisor> yep h264
[19:24:53 CEST] <marquisor> DVB-S2
[19:25:02 CEST] <furq> yeah rtmp is h264/aac
[19:25:02 CEST] <Guest22458> JEEB : This way correct ?
[19:25:04 CEST] <Guest22458> ffmpeg -thread_queue_size 512 -f x11grab -vsync 0 -s 640x360 -r 2 -i :0.0+0,0 -f null -thread_queue_size 512 -c:v h264_omx -b:v 500k -bufsize 4000k -f flv rtmp://live.twitch.tv/app/
[19:25:09 CEST] <JEEB> marquisor: is this for an internal or external network?
[19:25:11 CEST] <marquisor> direct stream from my settop box satellite receiver
[19:25:14 CEST] <marquisor> external
[19:25:24 CEST] <JEEB> ok, so no multicast with UDP :)
[19:26:04 CEST] <furq> Guest22458: check your cpu usage
[19:26:15 CEST] <furq> that'll still be doing a pixel format conversion, which there's not really any way around with x11grab
[19:26:46 CEST] <JEEB> marquisor: so what are the clients of this thing?
[19:26:53 CEST] <JEEB> what would be playing these streams?
[19:27:17 CEST] <marquisor> some different users, for private viewing
[19:27:31 CEST] <JEEB> well the thing I was pointing is do you need to support browsers
[19:27:43 CEST] <JEEB> or can the clients utilize some OSS player
[19:27:45 CEST] <marquisor> they all connect to it via mediaplayer f.e. vlc
[19:27:48 CEST] <JEEB> ok
[19:28:31 CEST] <marquisor> it's just to save bandwidth and keep the source "secret"
[19:28:34 CEST] <JEEB> marquisor: so what you need is something to give out the input stream as-is through HTTP or something
[19:28:40 CEST] <Guest22458> I may wait a few minutes since I need to recompile ffmpeg (I recompile without the nonfree option)
[19:28:41 CEST] <marquisor> like on this picture https://trac.ffmpeg.org/attachment/wiki/ffserver/ffserver_map.png
[19:28:48 CEST] <JEEB> uhh, you won't save bandwidth
[19:28:54 CEST] <JEEB> if you don't re-encode the stream
[19:28:57 CEST] <furq> he will if the server is remote
[19:29:04 CEST] <marquisor> yes server is remote
[19:29:06 CEST] <JEEB> well yea it depends *where* he means
[19:29:25 CEST] <furq> i assume he doesn't want all these people connecting to his house
[19:29:29 CEST] <marquisor> yep
[19:29:32 CEST] <marquisor> correct, furq
[19:29:37 CEST] <JEEB> anyways, vlc is one of those things that can serve stuff over http
[19:29:46 CEST] <marquisor> ok
[19:29:48 CEST] <JEEB> so you could pass the stream to a vlc on the server
[19:29:53 CEST] <marquisor> i considered vlc next.
[19:29:55 CEST] <JEEB> and then you figure out the sout stuff
[19:30:02 CEST] <JEEB> to output as-is without re-encoding
[19:30:06 CEST] <JEEB> as http
[19:30:09 CEST] <furq> i was really hoping you were going to name something better than vlc and http
[19:30:19 CEST] <JEEB> well if he wanst the full DVB stream as-is
[19:30:20 CEST] <marquisor> :)
[19:30:25 CEST] <furq> i'd love an rtsp server or something which is as easy to work with as nginx-rtmp
[19:30:42 CEST] <JEEB> and has no requirement for web browser spport
[19:30:50 CEST] <JEEB> also man, nginx-rtmp brings out some weirdos
[19:30:51 CEST] <marquisor> JEEB: sounds good
[19:31:00 CEST] <furq> well yeah
[19:31:16 CEST] <furq> marquisor: https://github.com/arut/nginx-rtmp-module
[19:31:18 CEST] <JEEB> marquisor: you can hack the input through an ssh tunnel or something else
[19:31:23 CEST] <furq> if you don't mind reencoding the audio then that's pretty good
[19:31:29 CEST] <marquisor> JEEB: aaah read about that, yes
[19:31:33 CEST] <furq> and meets all your other requirements
[19:31:44 CEST] <marquisor> furq: i can spare cpu power for reencoding audio
[19:31:45 CEST] <JEEB> ok, the main point being does he want to change the stream at all
[19:31:50 CEST] <JEEB> *wants
[19:31:54 CEST] <marquisor> but for video it'd be critical
[19:31:58 CEST] <furq> it'd pretty much just be ffmpeg -i http://foo -c:v copy -c:a aac -b:a 128k rtmp://...
[19:32:37 CEST] <JEEB> furq: there was this chinese spammer who herped a derp when I told him to make things take something else (not owned by adobe) in when he asked FFmpeg to hack HEVC into FLV unofficially
[19:32:48 CEST] <furq> sounds like fun
[19:32:52 CEST] <marquisor> you two got two reasonable solutions :)
[19:32:54 CEST] <JEEB> because of nginx-rtmp most likely
[19:33:00 CEST] <furq> yeah
[19:33:01 CEST] <marquisor> gonna try it like that
[19:33:11 CEST] <furq> even if ffmpeg had done that, what does he think clients will make of it
[19:33:36 CEST] <furq> or servers for that matter
[19:33:43 CEST] <marquisor> i have to ask, that rtmp:// doesn't need a running ffserver then?
[19:33:45 CEST] <JEEB> yea, not sure how much the servers actually parse it
[19:33:47 CEST] <marquisor> both solutions via ssh tunnel?
[19:33:48 CEST] <furq> no
[19:33:52 CEST] <marquisor> ah ok
[19:34:02 CEST] <JEEB> marquisor: it needs a TCP connection to nginx with the nginx-rtmp module ocnfigured
[19:34:08 CEST] <marquisor> kk
[19:34:10 CEST] <marquisor> i see
[19:34:11 CEST] <JEEB> the nginx will then serve whatever you configured
[19:34:14 CEST] <furq> yeah you don't need an ssh tunnel for nginx
[19:34:29 CEST] <kepstin> obviously you can run it through ssh or vpn or whatever if you want to tho.
[19:34:32 CEST] <JEEB> well, you can still do it to further secure the pushing
[19:34:40 CEST] <JEEB> vpn or port forward
[19:34:41 CEST] <marquisor> yep
[19:34:41 CEST] <furq> you could
[19:34:43 CEST] <marquisor> ok
[19:34:52 CEST] <marquisor> but won't need. it's not a permanent setup
[19:34:54 CEST] <furq> although you can just deny publish all and whitelist your ip
[19:35:08 CEST] <furq> or have some hacky password auth like i have
[19:35:26 CEST] <marquisor> just for watching 24h Race on this weekend ;)
[19:35:42 CEST] <furq> is it the vln this weekend
[19:35:50 CEST] <marquisor> Nürburgring
[19:35:52 CEST] <furq> yeah
[19:35:54 CEST] <marquisor> Germany
[19:36:53 CEST] <furq> oh it's a different 24 hour race
[19:37:01 CEST] <furq> i forgot they have more than one
[19:37:11 CEST] <furq> i'll be busy with monaco and indy anyway ;_;
[19:37:24 CEST] <marquisor> http://www.nuerburgring.de/en/events-tickets/automobile/adac-zurich-24-hour-race.html
[19:38:06 CEST] <marquisor> tomorrow qualifying, first general rehearsal for the stream planned...
[19:38:15 CEST] <furq> http://www.nuerburgring.de/en/events-tickets/automobile/vln.html
[19:38:17 CEST] <furq> i was thinking of that one
[19:39:41 CEST] <furq> sounds better than the wec race that only goes round the go-kart track anyway
[19:41:28 CEST] <Guest22458> (still compiling)
[19:42:11 CEST] <marquisor> hehe it's full track
[19:42:24 CEST] <marquisor> and always a (the) big event in germany
[20:08:47 CEST] <Guest22458> (still compiling)
[20:13:20 CEST] <lystra> Anyone know if ffmpeg can hard burn more than one subtitle, one on top of the other to display multiple languages?
[20:15:32 CEST] <Guest22458> I'm back
[20:15:55 CEST] <Guest22458> I was wondering : What about using MP3 and not AAC encoder ? Maybe it will be ligther
[20:16:12 CEST] <Guest22458> Lystra : I don't know
[20:35:10 CEST] <furq> Guest22458: probably
[20:35:24 CEST] <furq> you might want to try with fdk-aac or libshine, those are both optimised for mobile
[20:35:41 CEST] <furq> idk if they'll be faster than lame on a pi zero though
[21:02:23 CEST] <ThugAim> Hey guys, been trying to concat several files but it would usually show up 1000 frames duplicated error or DTS out of order error. Converting and joining .mpeg and .mxf files with libx264 and a watermark
[21:03:07 CEST] <BtbN> with -f concat you can't concat arbitrary files
[21:04:18 CEST] <marquisor> can you encode them to "one format" first and after then concat?
[21:07:35 CEST] <llogan> michaelni: i'll be unable to clear the ML queue from May 30-June 15.
[21:08:53 CEST] <BtbN> marquisor, yes
[21:11:58 CEST] <ThugAim> :(
[21:12:27 CEST] <ThugAim> thanks BtbN and marquisor ... is there hope for this function in the future?
[21:12:59 CEST] <ThugAim> also, how can I specify the watermark to come in at specific times?
[21:13:02 CEST] <BtbN> no, the concat demuxer is litterally just cat filea.mpeg fileb.mxf > inputfile.something
[21:13:03 CEST] <marquisor> you could write a quite simple shell script for that
[21:13:18 CEST] <BtbN> Use the concat filter if you want to concat arbitrary stuff
[21:14:04 CEST] <ThugAim> I'll do some reading up and testing, you'll know if I've failed enough times. :D
[21:14:59 CEST] <furq> ThugAim: if you're reencoding anyway then -i foo.mxf -i bar.mpg -filter_complex concat=n=2:v=1:a=1
[21:15:36 CEST] <furq> https://ffmpeg.org/ffmpeg-filters.html#Timeline-editing
[21:15:39 CEST] <furq> and you can use that with overlay
[21:19:05 CEST] <ThugAim> good info. will report back much later.
[21:25:06 CEST] <CesarS> Hello, I've started having an issue where a call to avformat_write_header would rewrite my stream time_base. I think this is now by design, but unfortunately it broke the code I had before. Now my videos seem to have a crazy framerate like 1180 and I am not sure how to fix this... Would anyone try to help?
[21:25:43 CEST] <CesarS> I think I have to update the way I was computing the pts for each frame, but I am not sure how
[22:16:10 CEST] <Guest22458> I'm back
[22:16:27 CEST] <Guest22458> So I'm on raspberry pi zero, I use hardware accelerated h264_omx
[22:16:29 CEST] <Guest22458> ffmpeg -f x11grab -vsync 0 -i :0.0+0,0 -f null -c:v h264_omx -b:v 500k -bufsize 4000k -f flv rtmp://live.twitch.tv/app/live_157451802_XSl9Z3Z9wfoHstXOwBvoco3YU1eyaP
[22:18:56 CEST] <Guest22458> (Twitch key is fake of course)
[22:19:44 CEST] <llogan> Guest22458: no -maxrate? what's the "-f null" for?
[22:19:52 CEST] <ChocolateArmpits> Guest22458, are you sure the encoder initializes vbv without maxrate specified ?
[22:20:01 CEST] <furq> do -maxrate and -bufsize even work with h264_omx
[22:20:07 CEST] <furq> also is there a question
[22:20:08 CEST] <Guest22458> It"s just a command because CPU is overloaded, even with this test
[22:20:22 CEST] <llogan> furq: add -g to that list
[22:20:29 CEST] <furq> i think -g does
[22:20:49 CEST] <Guest22458> How can I optimize this command ?
[22:21:58 CEST] <furq> i'm not sure if there's much you can do
[22:22:05 CEST] <Guest22458> :(
[22:22:12 CEST] <furq> the only thing there that hits the cpu is the pixel format conversion
[22:22:19 CEST] <furq> and there's no way around that with x11grab afaik
[22:23:45 CEST] <Guest22458> ./ffmpeg -f x11grab -s 320x240 -r 5 -vsync 0 -i :0.0+0,0 -f null -c:v h264_omx -b:v 200k -bufsize 4000k -f flv test.flv
[22:23:56 CEST] <Guest22458> With this command I get a really low CPU usage
[22:24:12 CEST] <furq> yeah that seems right
[22:24:27 CEST] <Guest22458> The parameter -g may be to 0 for a lower CPU conso ?
[22:24:32 CEST] <furq> no
[22:25:12 CEST] <furq> frame size and framerate is about all you can do afaik
[22:25:39 CEST] <furq> also that "-f null" is doing nothing
[22:26:15 CEST] <Guest22458> WTF There is no MP3 codec in audio
[22:26:35 CEST] <furq> there's no built-in mp3 encoder
[22:26:39 CEST] <furq> you need to build with libmp3lame or libshine
[22:27:19 CEST] <Guest22458> ok
[22:27:36 CEST] <Guest22458> I suppose the option is --enable-libmp3lame ?
[22:27:54 CEST] <furq> yeah
[22:27:58 CEST] <furq> libshine might be better for a weak cpu
[22:28:04 CEST] <furq> no harm in doing both
[22:32:12 CEST] <Ozgr> hi, which metadata keys are supported for webm container by ffmpeg? i have found this information: https://wiki.multimedia.cx/index.php/FFmpeg_Metadata but webm is not listed. i thought that those supported by matrsoka could also be supported by webm, since it is derived from matroska but only title key is written on the file, not the description. thanks
[22:39:55 CEST] <Guest22458> Thanks
[23:06:53 CEST] <Mavrik> hmm, dafuq, new x264 is all over the place when it comes to output bitrate
[23:10:43 CEST] <BtbN> in cbr mode you mean?
[23:11:17 CEST] <kepstin> it had better not be all over the place in cbr mode. or vbv mode. or even vbr mode when averaged over longer times.
[23:11:44 CEST] <kepstin> now, crf mode, isn't the intent that the bitrate will be all over the place? :)
[23:13:10 CEST] <BtbN> even in cbr/vbv mode, it can be all over the place, as long as it does not use more than it should. x264 does not support a minrate
[23:13:14 CEST] <BtbN> at best you can turn on padding
[00:00:00 CEST] --- Thu May 25 2017

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