[Ffmpeg-devel-irc] ffmpeg.log.20190804

[burek]

[01:25:24 CEST] <n000g> No. :-( I'll do that.
[01:52:47 CEST] <Hello71> vidstab is better anyways, assuming you can wait for it
[02:15:32 CEST] <n000g> Ah, it's not really important, really. I was just playing around with a little digitized Super8 video.
[02:43:26 CEST] <whitestone> does someone know the default HLS parameters that youtube use in their live streams
[07:17:27 CEST] <KodiakIT[m]> So, not sure where else would be more appropriate to ask this... I was looking at some screenshots of transcoded videos and noticed that the VP8/9 shots seemed to have fuller color than the x264/5 shots. Does the former actually have a wider color gamut than the latter, or is it likely it was just something with the encoding opts?
[11:01:29 CEST] <emOne> I have a strange "video" format that vlc player plays through ffmpeg. The only problem is that a lot of frames are dropped
[11:01:30 CEST] <emOne> the format is mxg. It has video and audio. The video are jpeg images. It has jpeg key frames which are full jpeg files.
[11:01:30 CEST] <emOne> In between the jpeg key frames the video is recorded with partial jpeg tiles that contain only the changes in the images
[11:01:33 CEST] <emOne> it is not even displaying all keyframes ..
[11:02:24 CEST] <emOne> i tried with ffmpeg -vsync 0 -f mxg -i video.mxg vido.mp4
[11:06:29 CEST] <emOne> when I convert to jpegs I get more frames
[11:09:28 CEST] <emOne> If anyone wants to check this format out drop me a message and I can upload a sample
[11:21:13 CEST] <TheLink> hello all
[11:21:21 CEST] <JEEB> ohai
[11:22:01 CEST] <TheLink> oh, of course you're here, too :P
[11:22:34 CEST] <TheLink> I wasn't really successful finding official documentation of using the videotoolbox hardware encoding with ffmpeg on macos
[11:23:17 CEST] <TheLink> only external links which were quite rudimentary
[11:23:18 CEST] <TheLink> is there such a thing?
[11:25:23 CEST] <TheLink> it seems to work so far (job is still running) and is blazingly fast on this macbook with t2 processor but I'd like to know more about which options are there to configure
[11:44:27 CEST] <durandal_1707> emOne: why you force mxg demuxer?
[11:45:11 CEST] <emOne> durandal_1707: what should I try instead?
[11:45:41 CEST] <durandal_1707> just -i doesnt work?
[11:48:49 CEST] <emOne> without -f mxg you mean?
[11:51:17 CEST] <emOne> durandal_1707: it isn't pretty
[11:51:27 CEST] <emOne> durandal_1707: should I send you a sample?
[11:51:54 CEST] <durandal_1707> what is not pretty?
[11:52:29 CEST] <durandal_1707> just pastebin ffmpeg -i output?
[11:53:19 CEST] <emOne> https://gofile.io/?c=4zSzO7
[11:54:31 CEST] <durandal_1707> im not on desktop, pastebin "ffmpeg -i that_file" output
[11:55:10 CEST] <emOne> 1 sec
[11:57:08 CEST] <emOne> https://pastebin.com/ffef3Zed
[11:58:55 CEST] <durandal_1707> so it only drcodes 14 frames?
[11:59:33 CEST] <durandal_1707> best to open ticket on trac and someone will look at that bug
[12:01:37 CEST] <emOne> durandal_1707: when I output to jpg it produces 42 jpg frames
[12:02:15 CEST] <emOne> but I think I remember that it also has partial jpg frames, which are just the tiles inside the image that changed
[12:02:28 CEST] <emOne> it is one strange format, but it never worked properly in ffmpeg
[12:02:48 CEST] <durandal_1707> is that 42 frames correctly looking?
[12:15:19 CEST] <durandal_1707> emOne is that 42 frames correctly looking?
[12:16:04 CEST] <emOne> they look correct yes durandal_1707
[12:17:48 CEST] <emOne> someone more knowledgable should have a look because something is not right though
[12:18:09 CEST] <emOne> I there are missing frames in between
[12:18:14 CEST] <emOne> I think *
[12:22:17 CEST] <durandal_1707> feel free to open ticket, then sure someone will look
[12:26:03 CEST] <emOne> durandal_1707: thank you. I will do
[12:27:07 CEST] <emOne> durandal_1707: I think the company behind the video format probably just made an awful and buggy video format
[12:35:25 CEST] <TheLink> interestingly it looks like quicktime player can't play the resulting file
[12:35:57 CEST] <TheLink> iina and so mpv can
[12:36:16 CEST] <TheLink> though seeking results in image distortion
[12:37:36 CEST] <TheLink> ffplay doesn't seem to have this issue
[12:42:13 CEST] <TheLink> ok, need to take that back
[12:42:46 CEST] <TheLink> as ffplay has no seekbar I only tested arrow key seeking which works fine
[12:43:16 CEST] <TheLink> so does it in iina and mpv
[12:43:20 CEST] <TheLink> only big jumps with seekbar result in image corruption
[20:48:49 CEST] <devsnek> i'm seeing a large delay when doing `ffmpeg -f pulse -i default`
[20:49:17 CEST] <devsnek> is there a way to reduce the delay? i want to sync it up with `ffmpeg -f x11grab` which is near instant
[22:13:34 CEST] <tommy``> i've a 1920x1080p with dar 4:3 how can i convert in 1920x1080 with dar 16:9 and black bar left and right?
[22:27:41 CEST] <Mavrik> Are you sure it's 1920x1080?
[22:28:02 CEST] <Mavrik> And not 1440x1080
[22:28:04 CEST] <Mavrik> ?
[22:28:07 CEST] <tommy``> meida iinfo says 1920x1080 4:3
[22:28:16 CEST] <JEEB> check ffprobe -v verbose FILE
[22:28:21 CEST] <Mavrik> What does ffprobe say? Including SAR?
[22:29:08 CEST] <tommy``> https://paste.ofcode.org/KW5qzxZhrdFUd8i5W5JfQ7
[22:30:06 CEST] <tommy``> Stream #0:0: Video: h264 (High), 1 reference frame, yuv420p(progressive, left), 1920x1080 (1920x1088) [SAR 675:896 DAR 75:56], SAR 180:239 DAR 320:239, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
[22:30:18 CEST] <JEEB> alright, so it indeed is 1920x1080 but with a funky aspect ratio :)
[22:31:17 CEST] <JEEB> anyways, you can scale+pad if you need to squeeze it to sar 1:1 and then pad
[22:31:31 CEST] <JEEB> although to be honest I would keep it as-is unless you really need to start touching it
[22:31:44 CEST] <JEEB> if some plastic box needs sar 1:1, then it might be worth trying to re-encode it
[22:32:19 CEST] <tommy``> i want to change like this:
[22:32:21 CEST] <tommy``> Stream #0:0: Video: h264 (High), 1 reference frame, yuv420p(tv, bt709, progressive, left), 1920x1080 (1920x1088) [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
[22:32:47 CEST] <JEEB> if the content is actually non 1:1 then you squeeze and pad. so two filters. scale and pad
[22:33:45 CEST] <tommy``> ffmpeg -i video.mkv -vf scale=1920x1080,setdar=16:9 output.mkv ?
[22:35:06 CEST] <DHE> doesn't mkv allow the container to specify an aspect ratio?
[22:35:21 CEST] <DHE> could this be fixed with an mkv-specific tool to just edit the mkv without transcoding?
[22:46:48 CEST] <JEEB> tommy``: if the content is actually 16:9 then just remux with 16:9
[22:46:56 CEST] <JEEB> in mkvmerge or so :p
[22:47:01 CEST] <JEEB> no need to re-encode
[22:50:13 CEST] <kepstin> if it's actually *supposed* to be 4:3 and you want to add black bars, then `-vf scale=1440:1080,setsar=1,pad=1920:1080:-1:0` should do that.
[23:01:49 CEST] <tommy``> kepstin with that command i have only a big black bar to the right and nothing to the left :o
[23:02:28 CEST] <kepstin> hmm, i might have misread the docs. use pad=1920:1080:240:0 then
[00:00:00 CEST] --- Mon Aug  5 2019