[Ffmpeg-devel-irc] ffmpeg.log.20151106

burek burek021 at gmail.com
Sat Nov 7 02:05:01 CET 2015


[00:26:52 CET] <kyshtynbai> Hi everyone! I'd like to cut 1 minute of footage begining from the 4th minute of the video file. What the proper command for this action should like? I'm trying this: 'ffmpeg -ss 00:04:00 -t 00:01:00 -i file.avi -acodec copy -vcodec copy out.avi' but it just cuts everything before 04 minute. It seems that -t key just doens't work.
[00:27:39 CET] <c_14> eeeeeh
[00:27:43 CET] <c_14> What part do you want to keep?
[00:28:40 CET] <kyshtynbai> from 00:04:00 to 00:04:30
[00:28:55 CET] <kyshtynbai> oh sory typo
[00:29:08 CET] <kyshtynbai> from 00:04:00 to 00:05:00
[00:29:29 CET] <c_14> That should work, it'll only cut on keyframes though
[00:29:51 CET] <kyshtynbai> hm. What's a keyframe?
[00:30:13 CET] <c_14> https://en.wikipedia.org/wiki/Group_of_pictures
[00:31:16 CET] <kyshtynbai> can I print to standart output the number of this things via ffmpeg?
[00:31:45 CET] <c_14> ffprobe -show_frames video, and then look for keyframe=1 or something
[00:31:51 CET] <c_14> Forget the exact syntax
[00:31:51 CET] <kyshtynbai> thanks
[00:38:14 CET] <kyshtynbai> this is strange. It doesn't cut 1 minute of the video. It cuts everything before the -ss time and nothing at all after -ss time
[00:41:25 CET] <Max-P> You might want to specify -t 1 as well, I think -ss just skips, so it's still converting whatever's after
[00:41:45 CET] <Max-P> (-t takes a number of frames, if I recall correctly)
[00:42:15 CET] <c_14> he did
[00:42:21 CET] <jorb> kyshtynbai: try putting the -t before your output file but after your -i
[00:42:35 CET] <jorb> order of parameters is important
[00:42:52 CET] <kyshtynbai> oh. Gonna try now thanks.
[00:43:35 CET] <c_14> -t should work before the input file
[00:43:38 CET] <c_14> but you can try it after
[00:43:41 CET] <c_14> it does do something different
[00:44:58 CET] <jorb> yeah i would think putting before would work too
[00:45:16 CET] <kyshtynbai> What has worked as I wanted it to work was re-encoding this video with my desired time parametrs (-async 1). Now I'll try this order of keys manipulation
[00:45:18 CET] <jorb> i've had a lot of trouble with it so i'm no expert
[00:47:43 CET] <kyshtynbai> and you know what? it helped
[00:47:50 CET] <kyshtynbai> jorb, thank you
[00:48:01 CET] <kyshtynbai> and thanks everyone
[00:48:37 CET] <kyshtynbai> but this is extremly strange weired and wrong. Position of keys MUST NOT affect result. At leas not like this.
[00:48:45 CET] <jorb> i'm running into issues splicing videos and trying to concat them back together... but first i'm going to compile the newest stuff
[00:49:00 CET] <jorb> positions of arguments really matters in ffmpeg
[00:49:51 CET] <kyshtynbai> this is not right IMHO. Or at least it should be clearly specified in documentation with damned CAPS LOCK on
[00:50:56 CET] <jorb> "As a general rule, options are applied to the next specified file"
[00:51:29 CET] <jorb> http://ffmpeg.org/ffmpeg.html#Description
[00:51:36 CET] <kyshtynbai> thanks
[00:51:54 CET] <jorb> lol, but it still doesn't explain why -t doesn't work on input if you ask me, but then again i haven't gotten that far through the man page
[00:52:40 CET] <kyshtynbai> but it doens't really make sence it this particular case. cause i've been thinkenig that -t should be aplied to the soruce file
[00:52:54 CET] <kyshtynbai> maybe this is a misunderstanding of course
[02:59:18 CET] <ploopkazoo> can ffmpeg convert an audio file and an image into a video with the given audio and a single frame of video that lasts the duration of the audio?
[03:00:16 CET] <scoofy> yes.
[03:04:25 CET] <ploopkazoo> when I do `ffmpeg -i audio.mp3 -i image.jpg out.mkv` it seems to not allow you to seek at all because it's a single frame. is there a way to fix that?
[03:04:31 CET] <ploopkazoo> perhaps by making more frames
[03:04:50 CET] <c_14> add -r 24 (or 30 or whatever) as an output option
[03:05:47 CET] <relaxed> doesn't he need -loop 1
[03:06:03 CET] <c_14> Well, I assume he had that.
[03:06:50 CET] <c_14> But yes, he would.
[03:07:02 CET] <relaxed> ffmpeg -i audio.mp3 -loop 1 -i image.jpg -shortest out.mkv
[03:07:33 CET] <c_14> You could also just get a player that lets you seek in streams with only 1 frame of video.
[03:12:55 CET] <ploopkazoo> is there a way to get it to encode faster while repeating the frame, or is that inevitably going to take extra time?
[03:14:21 CET] <relaxed> ploopkazoo: add -tune stillimage -preset veryfast
[03:15:28 CET] <ploopkazoo> thanks
[03:37:52 CET] <ploopkazoo> one more thing really quick; is there a way to do atempo but have it affect the pitch like increasing tempo normally does?
[03:52:53 CET] <durandal_1707> no, use rubberband
[04:48:32 CET] <jorb> so i can't get this video to work like i want.. i asked for help earlier and it got a lot better
[04:48:40 CET] <jorb> https://gist.github.com/anonymous/4cac887664a6d44813c5
[04:49:28 CET] <jorb> the resulting video ends up with gaps between the concat'd streams
[04:49:41 CET] <jorb> and audio is not sync'd up with video
[04:51:08 CET] <jorb> i'm guessing the biggest red flag is the output of the concat operation
[04:51:14 CET] <jorb> lots of "Non-monotonous DTS in output stream" warnings
[04:53:11 CET] <jorb> the intermediate videos have a very specific start time as well, i'm wondering if making them more precise would help
[04:53:18 CET] <jorb> so like... Duration: 00:00:06.13, start: 0.128000
[04:54:50 CET] <jorb> i'm thinking maybe if the videos don't start at a time stamp other than 0.0000000 than the concat'd stream will have extra padding in the audio or video stream dunno
[05:14:47 CET] <kyshtynbai> Hmmm. I can't use negative values to use fade out filter on the end of the file, can I. It is necessery to know exact quontity of frames?
[06:27:03 CET] <Izy> Hello!
[09:32:54 CET] <nvidia-problem> Hello, I tried to compile ffmpeg with NVENC support, but for some reason it's not working. My GPU is GeForce GTX 880M and here's the script used to compile ffmpeg http://pastebin.com/DWknAZ3s
[09:33:24 CET] <nvidia-problem> error message I got from trying to capture my screen: http://pastebin.com/15ts4cCw
[09:34:08 CET] <Ulrar> Hi, what lib do I need to compile ffmpeg with to be able to use drawtext with alpha ?
[09:34:18 CET] <Ulrar> drawtext works, but no alpha support
[10:43:02 CET] <JamJams> Question, when moving from avpicture_get_size() to av_image_get_buffer_size() is align just frame->linesize?
[10:46:52 CET] <waressearcher2> JamJams: hallo
[10:47:02 CET] <JamJams> hi
[10:47:13 CET] <waressearcher2> JamJams: wie gehts ?
[10:47:28 CET] <JamJams> ?
[10:50:26 CET] <JamJams> Never mind I see now it's just 1
[11:42:14 CET] <codedigger> Hello everyone
[11:42:31 CET] <codedigger> I have question about ffmpeg and ffserver
[11:44:27 CET] <codedigger> I would like to add some padding in input live stream (scale=... and pad=...). Works with ffmpeg and writing to local disk, but how can I pass this to ffserver?
[12:17:24 CET] <waressearcher2> codedigger: hallo
[12:17:38 CET] <codedigger> Hi
[12:17:54 CET] <waressearcher2> codedigger: wie gehts ?
[12:20:17 CET] <codedigger> Sorry, only Polish or English. But thanks, fine.
[12:52:58 CET] <StephenLynx> hey, I am trying to make desktop recordings with ffmpeg but there is something weird with colors. http://i.imgur.com/Y2LOpE5.png
[12:53:19 CET] <StephenLynx> I tried using both ffmpeg -video_size 700x420 -framerate 10 -f x11grab -i :0.0+50,0 -ab 96k -ar 44100 -b 345k  test2.webm
[12:53:29 CET] <StephenLynx> and ffmpeg -f x11grab -s 1024x768 -r 24 -i :0.0 -deadline realtime -b 5000000 -minrate 200000 -maxrate 40000000 test3.webm
[12:53:45 CET] <StephenLynx> in both this problem occurred.
[12:53:58 CET] <StephenLynx> when I record with mp4 it works fine.
[12:54:23 CET] <StephenLynx> this was the command I used to record with mp4 ffmpeg -video_size 700x420 -framerate 10 -f x11grab -i :0.0+50,0 test.mp4
[16:47:48 CET] <ploopkazoo> when I use an image as an input to ffmpeg it seems to compress and pixelate the image quite a bit. is there a way to prevent that? I'm outputting to .webm so `-vcodec copy` won't work
[16:48:35 CET] <ChocolateArmpits> ploopkazoo: Did you specify bitrate ?
[16:48:59 CET] <ploopkazoo> no
[16:49:18 CET] <ChocolateArmpits> then try doing that something like -b:v 1000k
[16:49:30 CET] <ChocolateArmpits> you can decrease the value if it's just a looping image
[16:49:39 CET] <ChocolateArmpits> to make the file smaller
[16:49:47 CET] <ploopkazoo> yeah it's just one image
[16:50:00 CET] <ChocolateArmpits> Are you embedding it as album art ?
[16:50:07 CET] <ChocolateArmpits> or actually rendering a video track out of it ?
[16:50:17 CET] <ploopkazoo> video
[16:50:24 CET] <ChocolateArmpits> Yeah then specify the bitrate
[16:50:50 CET] <ploopkazoo> is there a way to make the bitrate the same as the input?
[16:51:16 CET] <ChocolateArmpits> Well images doesn't have a "bitrate" concept. Maybe you mean to look like the input?
[16:51:21 CET] <ChocolateArmpits> don't*
[16:51:54 CET] <ploopkazoo> the output "bitrate" would just be the original image filesize, right?
[16:52:12 CET] <ChocolateArmpits> Nah, it's how much bits should be allocated per second on average
[16:52:22 CET] <ploopkazoo> ah
[16:52:25 CET] <ChocolateArmpits> when encoding it as a sequence of images you see
[16:54:47 CET] <ploopkazoo> is there a way to make it try to keep the quality approximately the same?
[17:16:36 CET] <DHE> which would be of higher image quality? 1080p but at slightly lower bitrate, or 1080i but at slightly higher bitrate?  both are made from the same pristine 1080i source
[17:17:33 CET] <ChocolateArmpits> DHE: That really depends on whether you need to keep the interlacing
[17:18:57 CET] <c_14> I think it depends on whether you deinterlace and then reinterlace or if you just passthrough the interlaced video.
[17:19:33 CET] <DHE> ChocolateArmpits: I don't. but these are my source options. furthermore the source is telecine'd so I may have to do a pullup on it
[17:19:49 CET] <DHE> I want progressive in the end, and will filter it myself if needed
[17:20:02 CET] <StephenLynx> anyone here uses ffmpeg to capture video of desktop to webm?
[17:20:06 CET] <StephenLynx> mine is getting messed colors.
[17:20:27 CET] <DHE> I'm doing it to MPEG2/H264. works okay-ish
[17:20:30 CET] <ChocolateArmpits> DHE: Then remove the telecine at all costs, there is no reason in trying to save it when it's not originally interlaced
[17:20:50 CET] <DHE> that means more work...
[17:21:30 CET] <c_14> StephenLynx: can your cpu handle that?
[17:21:34 CET] <ChocolateArmpits> DHE: Either you do the work, or will have to do it sometime later when the video is needed again
[17:21:52 CET] <StephenLynx> i think so, I can record mp4 and avi
[17:22:07 CET] <StephenLynx> but when I record on webm, the colors get messed, it also happens when I convert avi to webm
[17:22:14 CET] <StephenLynx> when I convert mp4 to webm it works fine.
[17:22:26 CET] <StephenLynx> http://i.imgur.com/Y2LOpE5.png the recorded webm
[17:22:30 CET] <c_14> Hmm, what's your command?
[17:22:49 CET] <StephenLynx>  ffmpeg -video_size 700x420 -framerate 10 -f x11grab -i :0.0+50,0 -ab 96k -ar 44100 -b 345k  test2.webm
[17:23:36 CET] <c_14> works for me
[17:23:36 CET] <c_14> colors are correct
[17:23:59 CET] <c_14> Wait, when you say colors, do you mean that ghosty ui stuff?
[17:24:10 CET] <StephenLynx> yes
[17:24:20 CET] <StephenLynx> and the actual video is grey
[17:24:28 CET] <c_14> What does it look like when you convert to avi?
[17:24:46 CET] <StephenLynx> same
[17:24:50 CET] <StephenLynx> from avi to webm
[17:24:58 CET] <StephenLynx> the original avi is fine though
[17:25:17 CET] <c_14> Can you give me a comparison, what does the original avi look like?
[17:26:10 CET] <StephenLynx> http://i.imgur.com/voozOjI.png
[17:27:06 CET] <c_14> Can you pastebin the complete console output of `ffmpeg -i avi out.webm' ?
[17:28:06 CET] <StephenLynx>   built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
[17:28:06 CET] <StephenLynx>   configuration: --enable-libvpx
[17:28:06 CET] <StephenLynx>   libavutil      54. 31.100 / 54. 31.100
[17:28:06 CET] <StephenLynx>   libavcodec     56. 60.100 / 56. 60.100
[17:28:06 CET] <StephenLynx>   libavformat    56. 40.101 / 56. 40.101
[17:28:06 CET] <StephenLynx>   libavdevice    56.  4.100 / 56.  4.100
[17:28:06 CET] <StephenLynx>   libavfilter     5. 40.101 /  5. 40.101
[17:28:11 CET] <StephenLynx>   libswscale      3.  1.101 /  3.  1.101
[17:28:12 CET] <StephenLynx>   libswresample   1.  2.101 /  1.  2.101
[17:28:12 CET] <StephenLynx> avi: No such file or directory
[17:28:13 CET] <StephenLynx> my bad, forgot the pastebin
[17:28:19 CET] <c_14> pastebin, as in a pastebin service
[17:28:21 CET] <c_14> like pastebin.com, pastie.org, ix.io
[17:28:34 CET] <c_14> "avi" is the name of your avi file
[17:29:12 CET] <StephenLynx> sec
[17:30:12 CET] <StephenLynx> http://pastebin.com/ZhSVt8pX
[17:35:20 CET] <c_14> And the colors in that output video are corrupted?
[17:36:53 CET] <StephenLynx> yes.
[17:37:05 CET] <StephenLynx> it has no colours aside from a ghostish UI
[17:37:34 CET] <c_14> Can you try the same command with a static build?
[17:37:50 CET] <c_14> http://johnvansickle.com/ffmpeg/
[17:37:51 CET] <c_14> Preferably the git one
[17:39:55 CET] <StephenLynx> the git one? isn't it from master's head?
[17:40:05 CET] <c_14> yes
[17:40:36 CET] <c_14> master HEAD is recommended. Especially for verifying bugs.
[17:43:16 CET] <StephenLynx> the 2.8.1 had the same issues, the git one couldn't be opened
[17:43:29 CET] <c_14> Couldn't be opened?
[17:43:33 CET] <c_14> What error did it give?
[17:43:55 CET] <StephenLynx> I just couldn't extract by opening directly. trying to download.
[17:44:54 CET] <StephenLynx> same
[17:44:58 CET] <StephenLynx> sergio at sergio-desktop:~/ffmpeg-git-20151106-64bit-static$ ./ffmpeg -video_size 700x420 -framerate 10 -f x11grab -i :0.0+50,0 -ab 96k -ar 44100 -b 345k  test2.webm
[17:45:11 CET] <StephenLynx> this was the command, stopped recording with ctrl+c
[17:45:44 CET] <c_14> Can you try encoding with libx264?
[17:45:50 CET] <c_14> -c:v libx264 out.mkv or something
[17:46:10 CET] <c_14> Might be the yuv conversion failing on your system
[17:46:17 CET] <StephenLynx> i don't have it installed, will be back in a moment.
[17:46:21 CET] <StephenLynx> I tried in both centOS and ubuntu
[17:46:22 CET] <c_14> The static build has it
[17:46:27 CET] <StephenLynx> ah
[17:46:28 CET] <StephenLynx> ok
[17:47:19 CET] <StephenLynx> nope, that worked fine.
[17:47:30 CET] <c_14> weird
[17:47:34 CET] <StephenLynx> :v
[17:48:02 CET] <c_14> Can you pastebin the output of that conversion?
[17:48:08 CET] <StephenLynx> the mkv recording?
[17:48:11 CET] <c_14> yes
[17:49:07 CET] <StephenLynx> http://pastebin.com/srQkZtNe
[17:50:00 CET] <c_14> It's the same colorspace conversion.
[17:50:10 CET] <c_14> hmm
[17:50:25 CET] <StephenLynx> v:
[17:50:34 CET] <c_14> Can you reproduce this issue on a different computer and/or upload a short sample with which you can reproduce the issue?
[17:50:54 CET] <StephenLynx> yes, the same thing happened on my centOS laptop
[17:51:08 CET] <StephenLynx> I can give you the webm.
[17:51:16 CET] <StephenLynx> that has the wrong colors.
[17:51:55 CET] <c_14> That might be good to test if it's a playback error.
[17:52:16 CET] <StephenLynx> sec
[17:52:22 CET] <c_14> Oh, does converting from the H264 mkv to webm also cause the color issues?
[17:52:28 CET] <StephenLynx> dont know.
[17:52:37 CET] <StephenLynx> I know that converting mp4 > web is fine.
[17:52:49 CET] <StephenLynx> so I think playing is fine on my side, never had any issues with webms
[17:53:07 CET] <StephenLynx> I have been working with thumbnailing from for a while now
[17:55:41 CET] <StephenLynx> https://seacloud.cc/f/c3abd23306/?raw=1 c_14
[17:56:47 CET] <c_14> Colors look fine to me.
[17:57:19 CET] <c_14> https://dl.c-14.de/t/shot0002.png
[17:57:46 CET] <StephenLynx> well, fuck me sideways.
[17:57:57 CET] <StephenLynx> so it just happens when I play the webm's I record myself.
[17:58:02 CET] <c_14> What are you using to play the webm?
[17:58:05 CET] <StephenLynx> firefox.
[17:58:10 CET] <c_14> Maybe it doesn't like yuv444p
[17:58:15 CET] <StephenLynx> never had a single issue with it.
[17:58:25 CET] <c_14> Ah, yep.
[17:58:30 CET] <c_14> Firefox fucks up with the colors here to.
[17:58:32 CET] <c_14> *too
[17:58:35 CET] <StephenLynx> :v
[17:58:37 CET] <StephenLynx> ok, good.
[17:58:50 CET] <StephenLynx> so its something between the way I record the webm and the way firefox plays it.
[17:59:10 CET] <c_14> add -pix_fmt yuv420p
[17:59:23 CET] <c_14> Before the output file and after the input file when recording/converting.
[18:01:02 CET] <StephenLynx> no cigar.
[18:01:09 CET] <StephenLynx> both with my installed ffmpeg and the git one.
[18:01:17 CET] <c_14> Didn't help?
[18:01:24 CET] <StephenLynx> no difference at all.
[18:01:29 CET] <c_14> Can I see the command output?
[18:02:01 CET] <StephenLynx> http://pastebin.com/PJfMrK0U
[18:02:59 CET] <c_14> u
[18:03:05 CET] <c_14> ^ignore that
[18:03:15 CET] <StephenLynx> :v k
[18:06:01 CET] <c_14> Seems to work for me though.
[18:06:02 CET] <c_14> What version of firefox?
[18:18:31 CET] <StephenLynx> 42.0
[18:18:47 CET] <StephenLynx> the one on centOS is a little older I guess
[18:19:31 CET] <StephenLynx> but you just said the colors were wrong for you too. or are you talking about webm that you record and the are fine on your firefox?
[18:20:03 CET] <c_14> yuv444p webm have broken colors, yuv420p webm are fine
[18:21:01 CET] <StephenLynx> ok, so
[18:21:29 CET] <StephenLynx> if you use 420p they are fine, if you use 444p they are broken, if I use either they are broken?
[18:22:15 CET] <StephenLynx> ./ffmpeg -video_size 700x420 -framerate 10 -f x11grab -i :0.0+50,0 -ab 96k -ar 44100 -b 345k -pix_fmt yuv420p test2.webm this was my command
[18:23:41 CET] <c_14> Use -b:v instead of -b, but ye that works for me.
[18:23:47 CET] <StephenLynx> hold on
[18:24:00 CET] <StephenLynx> I fucked up something before, with 420 it werked :v
[18:24:01 CET] <StephenLynx> thanks
[18:24:47 CET] <StephenLynx> I was probably looking at the wrong file before.
[18:26:47 CET] <StephenLynx> another thing, how do I get a specific window id so I can use it instead of specifying a location on the desktop?
[18:37:25 CET] <c_14> There's presumably a program for that.
[18:37:28 CET] <c_14> somewhere
[18:37:39 CET] <ChocolateArmpits> try OBS
[18:37:46 CET] <ChocolateArmpits> Open Broadcast Software
[18:37:59 CET] <ChocolateArmpits> the multiplatform release
[18:38:12 CET] <ChocolateArmpits> At least on Windows it can grab specific windows, monitors and more
[18:39:29 CET] <Fyr> guys, how to rescale video?
[18:39:48 CET] <ChocolateArmpits> -s [width]x[height]
[18:39:49 CET] <Fyr> I need to make FullHD hd720.
[18:39:55 CET] <DHE> -s 1280x720     or use "-vf scale=..." for more control
[18:40:07 CET] <Unknowing> ffmpeg -f concat -i my.txt -c copy -vcodec libx264  -preset veryslow -profile:v main -r 30 -g 60 -keyint_min 60 -x264opts "keyint=60:min-keyint=60:no-scenecut" -maxrate 1980k  -bufsize 1853k -vf scale=-1:720 -pix_fmt yuv420p -acodec libmp3lame -b:a 64k -ac 2 -ar 44100 -f flv
[18:40:17 CET] <Unknowing> I'm using this to stream to twitch is it alright ?
[18:41:17 CET] <StephenLynx> 720 is not fullhd
[18:41:24 CET] <StephenLynx> thats regular hd
[18:41:26 CET] <BtbN> a concat file doesn't look like a stream to me.
[18:41:31 CET] <StephenLynx> fhd is 1080
[18:42:36 CET] <Unknowing> I wan't  to stream random video files the command above is correct ? Also why did it just stop stop with no error
[18:43:28 CET] <c_14> Ran out of files to concat?
[18:45:09 CET] <Unknowing> is there a command to repeat from start again?
[18:45:15 CET] <Unknowing> First file*
[18:46:13 CET] <c_14> you can try the stream_loop option, I don't know how well that'll work with the concat demuxer though
[18:49:44 CET] <BtbN> ffmpeg will dump the files to twitch as fast as it possibly can, and Twitch will be kinda unhappy with that.
[18:49:51 CET] <BtbN> I think the option to stop that was -re
[18:50:19 CET] <BtbN> But you definitely should concat first, and then stream.
[18:50:54 CET] <Unknowing> How to limit that? With -re?
[18:53:46 CET] <Unknowing> frame= 6017 fps= 21 q=32.0 size=   40531kB time=00:03:20.49 bitrate=1656.1kbits/
[18:55:14 CET] <BtbN> Looks like your CPU isn't up to the setting you have chosen.
[18:56:08 CET] <Unknowing> Would add -threads 6 do any difference?
[18:56:27 CET] <BtbN> no.
[18:57:50 CET] <Unknowing> should i lower maxrate and bufsize?
[18:58:06 CET] <BtbN> You should propably not use the veryslow preset.
[18:58:13 CET] <BtbN> It's very slow.
[19:00:41 CET] <Unknowing> I update to medium
[19:01:20 CET] <Unknowing> frame= 4697 fps= 76 q=34.0 size=   33968kB time=00:02:36.47 bitrate=1778.3kbits/s dup=0 drop=4693
[19:02:39 CET] <ChocolateArmpits> dropping frames like crazy
[19:02:52 CET] <ChocolateArmpits> You should reset your timestamps with setpts and asetpts
[19:03:38 CET] <ChocolateArmpits> It would probably be better to have an mpv playlist and then pipe the output to ffmpeg
[19:05:25 CET] <Unknowing> That seems another chapter any guide?
[19:12:59 CET] <Unknowing> -filter:v "setpts=0.25*PTS"
[19:13:22 CET] <Unknowing> frame= 5690 fps= 76 q=29.0 size=   41337kB time=00:03:09.62 bitrate=1785.8kbits/s dup=0 drop=5686
[19:15:35 CET] <ChocolateArmpits> Unknowing: need to construct new timestamps, not use the original ones in the expression
[19:15:50 CET] <ChocolateArmpits> something like asetpts=N/SR/TB for audio or setpts=N/(FRAME_RATE*TB) for video
[19:16:10 CET] <ChocolateArmpits> grabbed examples from filters doc
[19:19:39 CET] <Unknowing> ffmpeg -f concat -i my.txt -c copy -vcodec libx264  -preset medium -profile:v main -r 30 -g 60 -keyint_min 60 -x264opts "keyint=60:min-keyint=60:no-scenecut" -filter:v "setpts='N/(FRAME_RATE*TB)" -maxrate 1780k  -bufsize 1853k -vf scale=-1:720 -pix_fmt yuv420p -acodec libmp3lame -b:a 64k -ac 2 -ar 44100 -f flv
[19:19:50 CET] <Unknowing> This is how it looks now
[19:20:08 CET] <ChocolateArmpits> you need to change the timestamps on the audio too
[19:20:43 CET] <ChocolateArmpits> else you will get timestamp mistmatch and that can result in all kinds of nasty bugs
[19:23:39 CET] <Unknowing> frame= 1743 fps= 76 q=33.0 size=   12092kB time=00:00:58.04 bitrate=1706.5kbits/s dup=0 drop=1739
[19:23:43 CET] <Unknowing> how does that look?
[19:23:52 CET] <ChocolateArmpits> not good, why is it dropping frames
[19:24:14 CET] <ChocolateArmpits> can you preview the output wth ffplay ?
[19:24:45 CET] <Unknowing> i preview it on twitch
[19:24:52 CET] <ChocolateArmpits> does it look any good there ?
[19:25:03 CET] <ChocolateArmpits> is the audio in sync etc ?
[19:25:07 CET] <Unknowing> Yes just my connection it keeps loading
[19:25:09 CET] <Unknowing> Yes
[19:25:17 CET] <ChocolateArmpits> well then what's the problem
[19:26:14 CET] <Unknowing> Resolution:1280 x 720 Display Resolution:726 x 408 FPS:30 Skipped Frames:147 Buffer Size: 6.25 sec. Latency to Broadcaster: 16.46 sec. Latency to Encoder: 15.46 sec. Playback Rate: 1823.71 Kbps
[19:26:58 CET] <Unknowing> Wanted to get rid of the dropped frames
[19:27:39 CET] <Unknowing> got an error now
[19:27:47 CET] <Unknowing> [h264 @ 0x3051180] Cannot use next picture in error concealment [h264 @ 0x3051180] concealing 8156 DC, 8156 AC, 8156 MV errors in P frame
[19:30:37 CET] <Unknowing> I removed asetpts=N/SR/TB and  setpts=N/(FRAME_RATE*TB)
[19:31:24 CET] <ChocolateArmpits> k
[19:51:27 CET] <Unknowing> ffmpeg -f concat -re -i my.txt -c copy -vcodec libx264  -preset fast -profile:v main -maxrate 1456k  -bufsize 1256k -vf scale=-1:720 -pix_fmt yuv420p -acodec libmp3lame -b:a 64k -ac 2 -ar 44100 -f flv
[19:51:48 CET] <Unknowing> Simple way this seem to work with no buffering also
[20:18:33 CET] <DHE> Has anyone seen an encoded video have this issue where keyframes have really bad quality and the video frequently goes to poor quality for a split second? And how to fix it? (video is mpeg2 at somewhat low bitrate)
[20:19:16 CET] <c_14> Does going to poor quality mean it gets blocky/fuzzy for a bit and then "refocuses"?
[20:19:22 CET] <DHE> yes
[20:19:44 CET] <DHE> and since mpeg2 has a low GOP interval this happens about 2 times per second
[20:20:08 CET] <c_14> Needs more bitrate
[20:20:28 CET] <DHE> clearly, but I can't provide I'm afraid...
[20:20:35 CET] <DHE> at least not much
[20:27:44 CET] <DHE> it appears the solution is to crank maxrate way up...
[20:27:57 CET] <DHE> which I'm HOPING is okay...
[20:28:09 CET] <c_14> Ah
[20:28:14 CET] <c_14> That'll allow the keyframes to be bigger.
[20:28:25 CET] <DHE> I have some fairly strict bitrate requirements to meet so let's see how that goes...
[20:51:33 CET] <Fyr> guys, how do I copy subtitles from input to output file?
[20:51:41 CET] <c_14> -c:s copy
[20:51:47 CET] <Fyr> thanks
[20:53:10 CET] <Fyr> c_14, do you know how to rescale video?
[20:53:10 CET] <Fyr> I used -c:v copy -vf scale=hd720, but it told me to piss off.
[20:53:25 CET] <c_14> What was the exact error?
[20:53:29 CET] <c_14> Oh, right.
[20:53:35 CET] <c_14> You can't scale and copy the video codec.
[20:53:38 CET] <c_14> You have to reencode
[20:54:20 CET] <Fyr> can I do it fast with keeping the original quality?
[20:54:48 CET] <BtbN> you can't scale without reencoding.
[20:54:48 CET] <c_14> use a lossless video codec
[20:54:52 CET] <c_14> It'll get rather big though
[20:55:23 CET] <Fyr> lossless - rawvideo or HEVC lossless parameter?
[20:55:48 CET] <c_14> rawvideo, huffyuv, ffv1, ffvhuff, utvideo
[20:56:04 CET] <c_14> x264 in lossless mode
[20:56:07 CET] <c_14> vp9 in lossless mode
[20:56:08 CET] <DHE> H264 in 4:4:4 mode is true lossless
[20:56:38 CET] <Fyr> if I play it with a player, it will rescale it automagically, on-the-fly. can I do the same?
[20:58:24 CET] <Fyr> meanwhile, it doesn't seem to loose quality.
[21:07:26 CET] <Fyr> guys, -c:a copies only the very first audio stream.
[21:07:32 CET] <Fyr> how do I copy all of them?
[21:08:20 CET] <BtbN> -c:a sets the codec for all audio streams, nothing else.
[21:08:27 CET] <BtbN> If you want a more complex stream mapping, use -map.
[21:08:40 CET] <Fyr> how do I just copy all audio streams?
[21:16:38 CET] <iksik_> hello
[21:17:15 CET] <iksik_> is it somehow possible to change filter settings on the fly, while live streaming?
[21:17:47 CET] <BtbN> no
[21:17:55 CET] <BtbN> At least not with the ffmpeg cli tool.
[21:18:21 CET] <BtbN> And I'm quite sure no lavf filter implements changing parameters at runtime.
[21:18:30 CET] <iksik_> is there anything that can help? some external tool perhaps? i'm interested with audio volume manipulation on selected channel
[21:20:07 CET] <c_14> Use something that uses the libav* api, or use the api yourself.
[21:21:40 CET] <durandal_1707> BtbN: volume supports runtime changing params
[21:22:12 CET] <BtbN> Is that exposed via the cli tool?
[21:24:08 CET] <durandal_1707> Via another filter
[21:24:45 CET] <durandal_1707> sendcmd/asendcmd
[21:26:01 CET] <beastd> Can't you give commands on stdin? Don't remember on the top of my head but I think I tested something like that years ago.
[21:26:44 CET] <BtbN> I remember there beeing stuff added for ffplay to change the volume using that filter.
[21:26:57 CET] <BtbN> But I never heard of dynamic filter parameters via the ffmpeg tool before
[21:36:43 CET] <beastd> BtbN: starting ffmpeg with filters and typing c works here
[21:42:40 CET] <beastd> not all filters support commands though. for example to change drawtext params you can use: drawtext -1  reinit y=100:fontcolor=white
[21:46:12 CET] <DHE> trying to use strict rate-control with mpeg2. Video options are: -b:v 3100k -g 15 -bf 2 -qmin 3 -maxrate:v 5500k -bufsize:v 1000k -c:v mpeg2video   but the resulting file doesn't seem to honour the bufsize. A rate limit test shows it hits my 5500k maxrate for extended periods (eg: 10+ seconds)
[21:51:37 CET] <bmurphy1976> anybody here have the experience to answer a question regarding packaging an MP4 video for html5 dash + drm?
[21:52:13 CET] <bmurphy1976> I'm trying to create a sample video, but everything I do seems to create a video where the meta data says it's encrypted (I think) but the video and audio streams are not actually encrypted
[22:39:28 CET] <ChocolateArmpits> DHE: what do you expect bufsize to do ?
[00:00:00 CET] --- Sat Nov  7 2015


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