[Ffmpeg-devel-irc] ffmpeg.log.20180601

burek burek021 at gmail.com
Sat Jun 2 03:05:01 EEST 2018

[00:00:17 CEST] <gcl_5> how do i disable warnings and let to pass progress info?
[00:01:25 CEST] <furq> gcl_5: -v error -stats
[00:02:29 CEST] <gcl_5> thxs furq
[01:51:21 CEST] <NasKar> can you automate options like lame when installing from ports with a command like "make -C /usr/ports/multimedia/ffmpeg clean install BATCH=yes" ?
[01:54:11 CEST] <furq> automate how
[01:54:27 CEST] <NasKar> with a batch script
[01:54:58 CEST] <furq> what bit do you want to automate though
[01:55:34 CEST] <NasKar> lame, smb, ass, opus and x265
[01:56:21 CEST] <NasKar> the command I referenced will install ffmpeg from ports but won't choose the options I want.
[03:20:39 CEST] <bashprogfortysix> sup guys pour a little cherry wine how come these ffmpeg recordings with ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+100,200 -f pulse -ac 2 -i default output.mkv https://trac.ffmpeg.org/wiki/Capture/Desktop are no good. just huge files, though i gues my opion is to find a better output file condition and or just convert the output file with bitrate plus.... window size, maybe find coordinates
[03:20:41 CEST] <bashprogfortysix> to square out.....
[03:22:38 CEST] <bashprogfortysix> oh i just noticed the slower preset in that link so maybe ill look that way first
[03:25:52 CEST] <bashprogfortysix> looks like that smaller preset nails it since lossless is still lossless lol!
[05:04:27 CEST] <sirjaymz> As TrueHD is in experimental, CLI came back and indicated '-strict -2' are necessary to use.. after specifying, the CLI window indicates something along the lines of 'mono and stereo are currently only usable ' or something along those lines..is there a schedule I can follow on expected feature complete timeframe?
[05:10:06 CEST] <zumba_addict> Is it possible to move each frame 5px to the right and rotate each frame maybe 0.1 degree?
[08:18:02 CEST] <bashprogfortysix> ffmpeg presets are pretty interesting
[08:18:12 CEST] <bashprogfortysix> thought the super slow does take awhile
[09:09:29 CEST] <bashprogfortysix> hey does any one have much experience with recording av to usb vhs from the vcr , i got a sample but find that in particular to watching the vhs in realtime on my desktop
[09:10:14 CEST] <bashprogfortysix> https://pastebin.com/g8AzuKwy
[09:10:34 CEST] <bashprogfortysix> this isnt working to where maybe its how actually these vhs' are playing though and
[09:11:06 CEST] <bashprogfortysix> i was watching and the audio was way lagging not bad but recording this way mplayer plays the output files much worse than ffplay
[09:11:45 CEST] <bashprogfortysix> i guess haha
[09:12:28 CEST] <bashprogfortysix> though if i get on it i expect to get the recording exactly as the vhsss are played importantly
[09:14:44 CEST] <bashprogfortysix> thought to let you know how to play the vhs youd be familiar :) just from /dev/video and arecord - | aplay -
[09:15:28 CEST] <bashprogfortysix> i also discovered my system had gst-launch-1.0 and started using that with it also so thats how my setup is doin it...
[11:05:55 CEST] <Zexaron> Hello
[11:06:56 CEST] <Zexaron> how do I check for the shared DLL version that gets loaded, I thought checking with defines but then I realized those are defined inside the source
[11:07:27 CEST] <Zexaron> or, the source doesn't get used in the program, only the DLLs, so it would work ?
[11:10:35 CEST] <BtbN> avcodec_version, avfilter_version, ...
[11:38:23 CEST] <Zexaron> BtbN: well I did it with minor and micro, major is already tied to the filename, higher major isn't problem but want to strictly avoid anything lower
[12:29:31 CEST] <BtbN> that's exactly what those functions are for.
[12:42:21 CEST] <Zexaron> ok
[14:33:28 CEST] <HarryFox> Hi guys i'm new here, so i begin you be patient a little :P
[14:35:29 CEST] <HarryFox> I have a task. There is a movie splited by 3 or more parts, and i need to stream it in real time as a single movie with single timeline, and only what i want to know, is it possible at all with ffmpeg?
[14:37:09 CEST] <DHE> concatenate? yes. there's a few ways to do it. search the wiki for concatenate
[14:43:09 CEST] <HarryFox> Not exactly concat. I need to stream it in real time while it downloading. But headers(or metadata, sorry for illiteracy, and for my English too) must be as it a full single movie.
[14:44:20 CEST] <Mavrik> You're describing concatenation :)~
[14:45:06 CEST] <DHE> concatenating from network sources can work, though I'm concerned that the second, third and any others may timeout while the first is playing
[14:45:24 CEST] <DHE> unless "network sources" is something simple like a samba share
[14:50:37 CEST] <HarryFox> And I could send headers(metadata) for the stream as if the stream a full movie with single timeline? It matters because of subtitles
[14:50:54 CEST] <HarryFox> If it so, it's great news for me!
[14:52:11 CEST] <Mavrik> Well, just use a right container.
[14:52:18 CEST] <Mavrik> E.g. MPEG-TS doesn't have any headers
[14:52:27 CEST] <Mavrik> Because it's meant for broadcast TV
[14:52:34 CEST] <Mavrik> So you just start sending it and concatenating it
[14:53:41 CEST] <DHE> timestamps are a container thing and you'll be generating the container as you go... if not outright transcoding the video/audio/subtitle streams
[14:54:06 CEST] <HarryFox> What I've done for this time it's trying to split every part of a movie to smaller parts as .ts files, made for it approximate m3u8, but it works ugly because every splitted part of video not exactly 10 second duration
[14:56:36 CEST] <HarryFox> So it's great news. It importants to me to know that it possible to do. Don't want to waste time for nothing :P
[14:56:46 CEST] <HarryFox> Thank you so much guys!
[14:57:36 CEST] <HarryFox> Will try to find solution in google (but something tells me that i will come back :c)
[15:07:33 CEST] <friki_> Hi! I can see at changelog of ffmpeg4.0 that ffserver is removed. Is there a replacement? I'm trying to serve a http live streaming (not HLS to avoid some delays). Is still possible?
[15:09:42 CEST] <DHE> use an external app that's better suited. the nginx-rtmp module (on top of nginx obviously) is popular
[15:10:08 CEST] <DHE> alternatively ffmpeg has an HLS output muxer which you can just write to disk in a directory served by a static content HTTP server (apache, nginx, whatever)
[15:10:31 CEST] <DHE> ... but it's http live streaming literally what HLS stands for?
[15:10:53 CEST] <friki_> any recomendation to reduce the delay as possible?
[15:12:06 CEST] <friki_> DHE: by "http live streaming" I mean an mp4 direct download. I don't know what's the common name for this type of streamings
[15:12:07 CEST] <DHE> HTTP is just not friendly in that regard. you may be best suited with a streaming protocol directly. like rtmp
[15:12:12 CEST] <furq> there's no good way of streaming to browsers without delay
[15:12:39 CEST] <friki_> furq: yap, it seems to be right
[15:12:46 CEST] <furq> if you don't care about browsers then nginx-rtmp is fine
[15:12:47 CEST] <DHE> when you say "delay" what do you mean? time from click to video starts playing? or it's a live stream and you want the delay between the camera and the user screen to be as short as possible?
[15:13:46 CEST] <friki_> delay between original stream is generated and displayed at the browser
[15:14:21 CEST] <friki_> "delay between the camera and the user screen to be as short as possible?" that's it
[15:14:45 CEST] <DHE> yeah. ditch the browser. use RTMP...
[15:15:45 CEST] <DHE> of course that means you'll need a player app that can do that. VLC maybe?
[15:16:20 CEST] <furq> vlc and mpv both work fine
[15:16:25 CEST] <furq> preferably mpv for obvious reasons
[15:17:20 CEST] <friki_> HLS with short segments... i think it's the best applicable option
[15:17:52 CEST] <furq> if you need browser support then you've no other choice really
[15:17:54 CEST] <friki_> i want to watch the video inside a web browser and avoid flash
[15:18:04 CEST] <furq> you're stuck with hls and dash
[15:18:05 CEST] <furq> and hls is simpler
[15:18:13 CEST] <DHE> even if a segment is 1 second (and I don't recommend that) it's still a good 3-4 seconds of latency on users.
[15:18:27 CEST] <furq> yeah you're looking at at least 10 seconds latency for hls
[15:18:34 CEST] <DHE> and that's not getting into encoder latency
[15:18:39 CEST] <friki_> furq: some years ago there are more options based over http
[15:18:46 CEST] <furq> encoder latency is pretty trivial compared to hls latency
[15:18:50 CEST] <furq> and other buffers and whatnot
[15:19:05 CEST] <DHE> yes. they still exist, but they are not realtime. they're not suitable for videoconferencing or whatever you're doing
[15:19:11 CEST] <furq> don't trip my "someone is enabling -tune zerolatency to send a stream to twitch" alarm
[15:19:23 CEST] <furq> my delicate heart can't take it
[15:19:27 CEST] <DHE> hahaha
[15:19:37 CEST] <friki_> DHE: how can i search more info about this options? :-)
[15:19:48 CEST] <DHE> which options?
[15:19:58 CEST] <furq> the only other option i know of that works in all browsers is webrtc
[15:20:11 CEST] <furq> and ffmpeg has nothing that will help you with that
[15:20:13 CEST] <friki_> i want to explore all http options
[15:20:24 CEST] <furq> and also that restricts you to baseline h264
[15:20:28 CEST] <friki_> I already know about HLS and DASH (based on segment files)
[15:20:40 CEST] <furq> there isn't really anything else
[15:20:49 CEST] <JEEB> as soon as you enter browsers, you're fscked regarding HTTP
[15:20:55 CEST] <JEEB> because XHR will buffer the whole thing
[15:21:02 CEST] <furq> browsers will only play mp4, you generally can't livestream mp4, and i don't think fmp4 works outside of hls/dash
[15:21:14 CEST] <furq> browsers meaning all browsers
[15:21:22 CEST] <friki_> can't do a "direct download" live streaming?
[15:21:27 CEST] <furq> not to browsers
[15:21:39 CEST] <JEEB> that's why the idiots keep working around it with trying to stream with websockets instead since that's implemented with streaming apis
[15:21:44 CEST] <furq> not for live streams anyway
[15:21:47 CEST] <furq> obviously you can do that for vod
[15:21:51 CEST] <JEEB> s/with trying/by trying/
[15:22:01 CEST] <friki_> i mean, http://myserver.com/live.mp4
[15:22:01 CEST] <JEEB> and lower latency stuff, yes, webrtc
[15:22:16 CEST] <furq> friki_: that doesn't work for live streaming for a variety of reasons
[15:22:25 CEST] <JEEB> friki_: if some browser supports fragmented isobmff it might work with a video tag
[15:22:26 CEST] <DHE> .mp4 works fine for pre-rendered videos. after the fact streaming, youtube style
[15:22:28 CEST] <JEEB> most likely not though
[15:22:40 CEST] <JEEB> but if you have the time and the way to serve that, feel free
[15:22:58 CEST] <friki_> .mp4 .mov .mkv (i don't mind the file format)
[15:23:05 CEST] <furq> well browsers will only play mp4 and webm
[15:23:17 CEST] <furq> and webm restricts you to vp9
[15:23:23 CEST] <furq> and you really don't want to use that for livestreaming
[15:27:07 CEST] <friki_> take a look at this live audio stream: http://rac1.radiocat.net/
[15:27:20 CEST] <furq> yeah audio is simpler
[15:27:30 CEST] <friki_> can't do it with video?
[15:27:41 CEST] <furq> icecast will serve webm
[15:27:46 CEST] <furq> i can't vouch for how well it works
[15:27:58 CEST] <furq> the problem with webm is it means you have to use libvpx which is incredibly slow
[15:36:52 CEST] <jphelps> Hello. I have a commercial DVD which has an A/V sync problem with one of its audio tracks. When played with mplayer using the -mc option (mplayer -mc 0 dvd://1), the a/v problem dissappears. I am trying to generate a valid movie file without transcoding that does nto have this problem.
[15:36:58 CEST] <jphelps> Any suggestions?
[15:41:19 CEST] <relaxed> does it happen at the start?
[15:44:09 CEST] <jphelps> No, it looks like a progressive shift
[15:44:18 CEST] <jphelps> It is not very bad in any case
[16:05:24 CEST] <chrysalis> is there a practical way to identify and cut/merge videos at keyframes, because from what i understand using -ss breaks seeking?
[16:08:06 CEST] <relaxed> chrysalis: have you seen https://trac.ffmpeg.org/wiki/Seeking ?
[16:10:56 CEST] <relaxed> you mean without transcoding?
[16:11:23 CEST] <chrysalis> yes, copy
[16:13:42 CEST] <relaxed> how does it break seeking?
[16:15:51 CEST] <chrysalis> i dont know, im confused, i just need to know the proper way to chop up a video with ffmpeg and replicate what i accomplish with bandicut using keyframes
[16:17:50 CEST] <sbraz> chrysalis: if you -c:v copy, it won't cut at -ss but at the nearest keyframe i think
[16:18:20 CEST] <sbraz> maybe not the "nearest", but the next keyframe or something, anyway it will properly cut on keyframe
[16:19:21 CEST] <anill> Hi FFMPEG people, i have a raw dump of RTP packets and want to convert it to .h264, can it be done via ffmpeg?
[16:19:39 CEST] <chrysalis> yes, but as i understand it it matters if you put -ss before or after -i file
[16:19:52 CEST] <chrysalis> this is whats confusing me
[16:20:18 CEST] <anill> chrysalis: is it for me?
[16:21:22 CEST] <sbraz> chrysalis: if you copy it doesn't matter i think
[16:21:39 CEST] <sbraz> it matters if you transcode, then if you put -ss after, it will do an exact seek and start transcoding there
[16:21:55 CEST] <chrysalis> it might cut at the keyframe, but itll play from the -ss position or sometghing like that
[16:24:18 CEST] <chrysalis> im not transcoding im copying, so you are saying it doesnt matter in this case?
[16:34:50 CEST] <furq> iirc it depends on the demuxer whether or not it'll cut properly at the nearest keyframe if you also have audio
[16:35:04 CEST] <furq> obviously the video stream will always cut at the nearest keyframe, but it may or may not seek the audio to that point before cutting
[16:57:17 CEST] <Satao> Hi all! I'm using the dashenc output to file, but it's writing to a temp file. Is it possible to change this behaviour?
[16:57:53 CEST] <Satao> or better... writing to a temp file and then moves/renames the file
[17:04:42 CEST] <TAFB_WERK> ffplay plays my ip camera perfect, ffmpeg does not. Can I stream data from ffplay to ffmpeg? :)
[17:08:07 CEST] <DHE> that's a surprise, unless the ffmpeg output has some kind of limitation that causes it to sputter. the camera does expect realtime streaming.
[17:08:26 CEST] <DHE> or a version mismatch?
[17:12:23 CEST] <kepstin> TAFB_WERK: ffmpeg isn't a player, I'm not sure what you mean by "plays my ip camera perfect"?
[17:13:19 CEST] <kepstin> i mean, you can sort of play video with ffmpeg by using an output format that shows stuff on the screen, but there's no attempt to time frames correctly there, so...
[17:17:36 CEST] <TAFB_WERK> kepstin: how can you say ffmpeg isn't a play? -c copy to "display" = player :)
[17:17:58 CEST] <TAFB_WERK> DHE: ffmpeg recording sputters, ffplay is smooth
[17:18:08 CEST] <Hello71> ffmpeg buffers
[17:18:20 CEST] <DHE> he just said ffmpeg isn't a player because, among other things, it doesn't bother with timing and stuff. it wants to transfer data in and out as quick as possible
[17:18:57 CEST] <kepstin> if you want to play something, use a tool designed for that, which will among other things correctly handle displaying frames at the correct time.
[17:19:18 CEST] <DHE> and sync the audio properly
[17:19:19 CEST] <TAFB_WERK> i'm trying to live stream my crappy ip camera to youtube, skips, studders, etc. looks fine in ffplay
[17:19:31 CEST] <TAFB_WERK> the stream has no audio
[17:19:39 CEST] <TAFB_WERK> I have to inject blank audio to get youtube to stream it
[17:19:50 CEST] <kepstin> oh, so you're *not* using ffmpeg as a player, you're using it as transcoder and network streaming tool.
[17:20:02 CEST] <TAFB_WERK> ffmpeg -rtsp_transport tcp -allowed_media_types video -i "rtsp://admin:admin@" -c copy -f h264 - | ffmpeg -f h264 -r 30 -i - -f lavfi -i anullsrc -b:a 2k -c:a aac -c:v copy -f flv "rtmp://a.rtmp.youtube.com/live2
[17:20:04 CEST] <kepstin> now we're starting to know enough to be able to help you :)
[17:20:21 CEST] <DHE> ... wat? why are you piping ffmpeg into ffmpeg?
[17:20:50 CEST] <TAFB_WERK> someone here gave me the command, worked fine with my old camera, not so much with my new one.
[17:20:52 CEST] <furq> changing the framerate i guess
[17:20:54 CEST] <kepstin> TAFB_WERK: that command will discard frame timing and cause all sort of problems (you're saying the stream is 30fps, but if the camera isn't actually doing 30fps it'll cause issues)
[17:21:12 CEST] <furq> but yeah that's probably going to work badly with a live input
[17:21:36 CEST] <furq> MAYBE that's why it's stuttering
[17:22:23 CEST] <TAFB_WERK> kepstin: the camera has a variable framerate :( i know :(
[17:23:09 CEST] <furq> doesn't flv support vfr
[17:23:20 CEST] <furq> actually nvm i bet youtube doesn't
[17:23:34 CEST] <TAFB_WERK> youtube for sure doesn't
[17:23:39 CEST] <kepstin> furq: yeah, it does, but the -r30 in that command makes it cfr, so...
[17:23:46 CEST] <furq> well yeah i'm saying he could skip that step
[17:24:01 CEST] <DHE> but only in the second half. the first half isn't forcing a framerate.
[17:24:06 CEST] <kepstin> a single ffmpeg command (no pipe), optionally with an fps filter to make it cfr, should work fine
[17:24:08 CEST] <furq> although if you want to make it cfr then might i suggest -vf fps=30
[17:24:26 CEST] <DHE> besides, variable FPS coercion and stream copy to raw h264 bitstream are not compatible
[17:24:36 CEST] <TAFB_WERK> i'll give that try, thx.
[17:24:37 CEST] <furq> yeah
[17:25:54 CEST] <kepstin> i'd expect yt live stuff should handle vfr stuff ok? they allow streaming from phones and such, iirc.
[17:26:18 CEST] <HarryFox> Few I found the answer on previous question, but result is unsatisfactory for me. Sad but concat of
[17:26:32 CEST] <DHE> sure, but he's doing full h264 stream copy the whole way through and discarding timing information in the pipe
[17:26:37 CEST] <HarryFox> mp4 streams it's too expensive by comp resources
[17:31:50 CEST] <manuelschneid3r> hi
[17:32:03 CEST] <manuelschneid3r> how can I avoid metadata to be removed by ffmpeg
[17:32:03 CEST] <TAFB_WERK> https://www.youtube.com/watch?v=dCBM91HT0Ck
[17:32:20 CEST] <TAFB_WERK> seems to be streaming pretty smooth with -vf fps=30
[17:33:59 CEST] <Hello71> what's the modern uncompressed or minimally (lossless) compressed video format?
[17:34:47 CEST] <Hello71> yuv4mpegpipe?
[17:35:26 CEST] <DHE> a number of options depending on CPU and size preferences. h264 with -qp 0 (colourspace permitting), ffv1, huffyuv are all popular choices
[17:37:29 CEST] <furq> Hello71: y4m is a container
[17:37:59 CEST] <HarryFox> Guys I hope you can help me with another question: I split a video to 15 sec .ts files, but duration of the files not direcly 15 sec and it brings troubles for m3u generation. So question is how can i get every file exact duration?
[17:38:10 CEST] <furq> rawvideo is uncompressed, ffvhuff is the fastest lossless codec (but nothing other than libavcodec supports it)
[17:38:16 CEST] <Hello71> doesn't it only hold uncompressed yuv
[17:38:20 CEST] <furq> yes
[17:38:25 CEST] <Hello71> y4m that is
[17:38:28 CEST] <furq> yes
[17:38:55 CEST] <furq> ffvhuff is fast enough that there's no point not using it
[17:39:07 CEST] <furq> but it obviously doesn't compress very well
[17:39:11 CEST] <Hello71> what do I put it in?
[17:39:23 CEST] <furq> mkv or nut are fine
[17:39:55 CEST] <Hello71> I think by default -c:v libx264 -f mp4 - | ffmpeg won't work
[17:40:44 CEST] <furq> it sure won't
[17:41:13 CEST] <furq> Hello71: ffmpeg -codecs | grep EV..S
[17:41:17 CEST] <furq> will list every lossless video encoder
[17:41:34 CEST] <furq> HarryFox: if you're splitting without reencoding then you're constrained by keyframes
[17:42:05 CEST] <furq> there's no solution other than reencoding or just not caring that your segments aren't all the same duration
[17:42:12 CEST] <furq> i would go with the latter because it doesn't matter that much in my experience
[17:43:34 CEST] <Hello71> huh, are LS new? I could swear it used to be fewer characters
[17:45:03 CEST] <Hello71> also it's weird that h264 is marked S but hevc isn't
[17:50:21 CEST] <Hello71> oh cool, ffserver might be getting unkilled
[18:06:53 CEST] <anill> Hi FFMPEG people, i have a raw dump of RTP packets and want to convert it to .h264, can it be done via ffmpeg?
[18:11:03 CEST] <BtbN> write a server that replay them?
[18:27:43 CEST] <HarryFox> furq: in my case it's very important to know exact duration, becaouse the creation of playlist file dependce on it.
[18:28:39 CEST] <HarryFox> Anyway now I'm trying to use ffprobe and catch em stdout with python
[18:31:09 CEST] <ChocolateArmpits> HarryFox, you can ask ffprobe for specific properties rather than parsing all of the output
[18:33:42 CEST] <HarryFox> yeah i know but somewhat it doesn't work at 100% with python subprocess, and stdout is None
[18:34:10 CEST] <HarryFox> but I think I found solution. Working on it
[18:36:02 CEST] <Hello71> unless you're sure what you're doing you should use check_call
[18:47:14 CEST] <HarryFox> Hello71: yeah it's much more convenient than Popen, thanks
[18:50:11 CEST] <Hello71> well no shit, https://docs.python.org/3/library/subprocess.html: "The recommended approach to invoking subprocesses is to use the run() function for all use cases it can handle. For more advanced use cases, the underlying Popen interface can be used directly."
[19:01:46 CEST] <HarryFox> Hello71: run() has been added with python 3.5 but in my case need python2.7 code compatible. It's not option for me
[19:02:21 CEST] <Hello71> if you want to capture the output then I guess it doesn't work
[19:04:52 CEST] <HarryFox> check_call it doesn't, but check_output is perfect
[20:14:01 CEST] <galassi_> Hiya guys, I'm trying to figure out why ffmpeg seems to possibly hang upon creating/opening a file upon attempting to stream from screen.
[20:15:16 CEST] <Durandal> Maybe it's not getting any data from the source?
[20:15:29 CEST] <galassi_> Possible, should I post the log?
[20:15:30 CEST] <Durandal> What is your commend line
[20:16:07 CEST] <galassi_> ffmpeg -loglevel 'debug' -report -nostdin -video_size 1024x768 -framerate 25 -t 00:00:10 -f x11grab -i :0.0+100,200 output.mp4
[20:16:42 CEST] <galassi_> it seems to stop recording the log at Successfully parsed a group of options.
[20:16:42 CEST] <galassi_> Opening an input file: :0.0+100,200.
[20:16:54 CEST] <galassi_> then it just hangs
[20:17:03 CEST] <galassi_> no crashes, and no output file is created
[20:17:29 CEST] <Durandal> Don't -f and -I need to come first?
[20:17:35 CEST] <galassi_> I have to ctrl c to stop it running
[20:17:41 CEST] <galassi_> will try that
[20:19:07 CEST] <Durandal> If you intend to output only 10 seconds of capture then -t needs to go after -i
[20:21:43 CEST] <galassi_> what would that command look like? I'm getting no such file or directory atm
[20:23:08 CEST] <galassi_> I just want to test and see if ffmpeg is able to run on this computer. I was given the task "Investigate why FFMPEG Isn't Working on Rushmore", and that is the extent of my knowledge at this point.
[20:29:28 CEST] <galassi_> it seems to hang at the same point when performing a grab with -i at this position:
[20:29:29 CEST] <galassi_>  ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg -loglevel 'debug'
[20:31:33 CEST] <Durandal> this is a similar command line that I use on windows
[20:32:12 CEST] <Durandal> ffmpeg -f gdigrab -i desktop -framerate 30 -t 10 "out.mp4"
[20:32:40 CEST] <DHE> order of args does matter. options before "-i" are configuration options for the input. otherwise they are configuration options for the output
[20:32:50 CEST] <Durandal> The general structure should be ffmpeg [GLOBAL PARAMS] [INPUT PARAMETERS] [INPUTS] [OUTPUT PARAMETERS] [OUTPUT]
[20:32:53 CEST] <Durandal> yeah
[20:33:40 CEST] <Durandal> ffmpeg -loglevel 'debug' -f x11grab -i :0.0 -video_size cif -framerate 25 /tmp/out.mpg
[20:34:23 CEST] <DHE> I would use -s instead of video_size for the input, and make sure you set it on the left side of -i
[20:34:42 CEST] <DHE> oh wait, I'm looking at the wrong options. ignore that
[20:36:17 CEST] <galassi_> yeah still hanging on opening an input file with: ffmpeg -loglevel 'debug' -f x11grab -i :0.0 -video_size cif -framerate 25 /tmp/out.mpg
[20:36:33 CEST] <galassi_> should I be looking at x11grab?
[20:36:35 CEST] <Durandal> ffmpeg -loglevel 'debug' -f x11grab -i :0.0 -framerate 5 -preset ultrafast out.mp4
[20:36:44 CEST] <Durandal> works for me on ubuntu
[20:36:56 CEST] <Durandal> do you need to demonstrate the x11grab works, or just ffmpeg in general?
[20:37:00 CEST] <DHE> framerate is an x11grab option, put it on the left side
[20:37:02 CEST] <kepstin> '-framerate' is also an input option, but yeah - sounds like the issue is in the connection to X to do the screen grabbing
[20:38:15 CEST] <galassi_> oh I am being told now, it's a setting in x2go that is the issue.
[20:38:45 CEST] <galassi_> there is a bug here related to it being disabled, but it has been addressed.
[20:39:55 CEST] <galassi_> just didn't get relayed to me until now.
[20:39:55 CEST] <DHE> so it's not really an X11 server?
[20:40:06 CEST] <galassi_> I guess not.
[20:41:11 CEST] <galassi_> or at least something in x2go is disabled so that x11grab will not work.
[20:42:13 CEST] <galassi_> Upon my boss seeing this chat screen, he immediately apologized about assigning this task so I guess it's all "sorted" atm.
[20:42:35 CEST] <galassi_> The mystery remains for now.
[20:42:41 CEST] <galassi_> ty for your help though guys
[21:32:10 CEST] <Xogium> hi :) I've downloaded a bunch of sounds which claimed to be stereo and 5.0 channels both, but I only got the 5.0 version. Is there any easy way to get these to stereo without too much tweaking and such ?
[21:32:34 CEST] <Xogium> note that I can't even play anything else than stereo here
[21:32:57 CEST] <c_14> ffmpeg -i file -ac 2 stereofile
[21:33:06 CEST] <c_14> might need codec/bitrate settings
[21:33:19 CEST] <Xogium> won't that cause an unbalanced sound ?
[21:33:25 CEST] <c_14> how so?
[21:33:29 CEST] <c_14> should do proper downmixing
[21:34:10 CEST] <Xogium> I'm not sure, it felt like I was missing 1 or 2 channels from the original
[21:34:22 CEST] <Xogium> a weird kind of flanger effect too
[21:34:29 CEST] <c_14> is the 5.0 version correctly tagged?
[21:34:34 CEST] <c_14> channels all in the right places?
[21:34:47 CEST] <Xogium> it should be
[21:34:55 CEST] <Xogium> how can I verify this to make sure ?
[21:37:29 CEST] <c_14> first check that the layout listed by ffprobe/ffmpeg is the one you're expecting. should list 5.0
[21:37:42 CEST] <c_14> but if they're incorrectly labeled you'd have to listen to each channel on it's own
[21:37:50 CEST] <c_14> or remove channels to find out which ones they actually are
[21:39:55 CEST] <Xogium> heh
[21:40:16 CEST] <Xogium> the rest of the files appears to be labled right, just this one that wasn't
[21:40:50 CEST] <Xogium> I definitely need to report this to the guys
[21:42:04 CEST] <Xogium> thank you c_14 :)
[21:42:17 CEST] <DHE> depending on the file format, you might be able to probe the file to see if it has multiple audio streams, and select which you want
[21:42:28 CEST] <Xogium> yeah that's wave
[21:42:32 CEST] <DHE> oh...
[21:45:14 CEST] <Xogium> I was going crazy with that file and tried answer from stackoverflow& They started to downmix in a weird way and using a filter and all, and I was like, surely downmixing properly can't be so complicated
[21:49:45 CEST] <DHE> "properly" can be is relative. how to mix 5 speakers down to 2 without clipping while still maintaining the right volumes for each speaker?
[21:58:39 CEST] <Xogium> DHE: yeah
[21:59:13 CEST] <Xogium> but I mean, for me setting to 2 channels was enough
[23:20:00 CEST] <Ars>  Hi guys
[23:20:00 CEST] <Ars> I am transcoding live stream to mpeg2
[23:20:00 CEST] <Ars> On VLC its perfect, but hardware doesn't accept stream an shows: PCR repetition errors
[23:20:31 CEST] <Ars> how fox PCR errors
[23:20:35 CEST] <Ars> fix
[23:21:40 CEST] <JEEB> Ars: the mpegts muxer should in theory generate proper PCR, how are your timestamps and what is your FFmpeg version?
[23:22:08 CEST] <JEEB> I've had issues with UDP multicast and really cringily strict hardware receivers, but not PCR so far
[23:23:26 CEST] <Ars> JEEB, ffmpeg version 4.0-static
[23:24:37 CEST] <Ars> i am using multicast
[23:24:45 CEST] <Ars> UDP
[23:30:37 CEST] <DHE> the mpegts muxer works best and is most compliant when run in CBR muxing mode. set -muxrate to a number that you will definitely never exceed (including the overhead of mpegts itself)
[23:30:57 CEST] <DHE> typically add your peak bitrates from all streams, add 10%, and you have a good estimate for the muxrate
[23:39:46 CEST] <Ars> DHE, thank you i will try
[00:00:00 CEST] --- Sat Jun  2 2018

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