[Ffmpeg-devel-irc] ffmpeg.log.20181130

[burek]

[00:06:45 CET] <bencc> I'm capturing a screen with low change rate. I would expect the file size to be relatively small
[00:06:47 CET] <bencc> "-vcodec libx264 -pix_fmt yuv420p -preset:v veryfast -crf 23"
[00:06:57 CET] <bencc> should I use something else to decrease the file size?
[00:07:40 CET] <furq> you could use a preset slower than veryfast
[00:07:59 CET] <furq> you could also try using something like minterpolate to remove dupe frames
[00:08:04 CET] <furq> but those should be very small anyway
[00:08:29 CET] <furq> also i'm guessing from yuv420p that this is going to youtube or similar, and idk how well they deal with vfr content
[00:08:34 CET] <furq> i assume they just convert it back to cfr
[00:15:54 CET] <bencc> furq: I'm not uploading to youtube
[00:16:03 CET] <bencc> just streaming from aws S3
[00:16:13 CET] <bencc> is there something better than yuv420p?
[00:16:39 CET] <bencc> I'm interested in reasonable file size, reasonable cpu and quality
[00:16:42 CET] <bencc> only 720p
[00:17:59 CET] <bencc> I thought that the codec job is to only keep changes between frames
[00:18:19 CET] <bencc> and a screencapture of mostly static content should be very efficient
[10:43:43 CET] <alimiracle> hi
[10:43:50 CET] <alimiracle> I use ffmpeg to split video to smaller chunks
[10:43:59 CET] <alimiracle> is 3 Seconds
[10:44:06 CET] <alimiracle> When I check the time to Every chunk
[10:44:12 CET] <alimiracle> its not  3 Seconds
[10:44:19 CET] <alimiracle> I use  this
[10:44:28 CET] <alimiracle> ffmpeg -i q.mp4 -vcodec copy -f segment -segment_time 3 lara%01d.mp4
[10:47:41 CET] <relaxed> alimiracle: stream copying will cut a key frames, so it won't be exactly 3 seconds. What kinf of times are you seeing?
[10:47:59 CET] <relaxed> cut at a key frame*
[10:50:53 CET] <relaxed> alimiracle: the segment muxer has -break_non_keyframes 1, but I'm not sure that's recommended for playback
[10:58:53 CET] <skident> Hi everyone.
[10:59:06 CET] <skident> I asked this question before but let's try again
[10:59:31 CET] <pink_mist> (if at first you don't succeed ...)
[11:00:03 CET] <skident> How to use loudnorm filter for livestream (with minimal latency)?
[11:00:34 CET] <skident> I mean to say in linear mode for sure
[11:48:55 CET] <skident> pink_mist: maybe it'll be better to investigate the code :)
[13:58:11 CET] <fred1807> I want to compress my videos to -crf 20 profile, I want to avoid compressing what is already good. Where should I look at/test for it?
[13:58:19 CET] <fred1807> can ffprobe tell me something?
[14:00:37 CET] <ariyasu> what do you mean by good?
[14:00:42 CET] <ariyasu> already at crf20?
[14:01:53 CET] <ariyasu> the info is in the x264 header, you can view it with a gui like media info
[14:02:13 CET] <ariyasu> to do it via cli with ffmpeg check the answer here https://superuser.com/questions/1264879/how-to-get-crf-info-of-a-video-file
[14:07:28 CET] <unlord> Is there a way to tell what version of libaom is integrated into ffmpeg?
[14:10:05 CET] <fred1807> ariyasu: Most of the videos I am converting to crf 20 are having theier bitrate reduced from ~10.000 to ~3.000 .... Can I assume the bitrate value is a good measure?
[14:26:21 CET] <BtbN> no
[14:26:35 CET] <BtbN> with crf it can very a whole lot
[15:22:33 CET] <fred1807> How can I get ffprobe bitrate into a variable (bash) ?
[15:25:21 CET] <fred1807> answer: ffprobe -hide_banner -loglevel fatal -show_format -print_format json combo-horizontal.mp4 | jq .format.bit_rate     ;)
[15:28:03 CET] <Mavrik> Isn't there a flat format that allows you to skip json parsing_
[15:28:26 CET] <furq> ffprobe -v error -show_entries format=bit_rate -of default=nk=1:nw=1
[15:30:20 CET] <fred1807> thx
[17:46:03 CET] <pagios> hi all, does anyone recommend a reliable ip camera with built in microphone to use for livestreaming conferences? I would like it to be a wireless ip camera that can stream using rtsp with audio and video. something like mevo but more flexible
[22:53:22 CET] <saml> give me one liner that implements gopro quik
[22:54:33 CET] <pink_mist> wow, that way of asking does not inspire me to want to help you at all, not that I could
[22:54:52 CET] <saml> ok give me money
[22:55:08 CET] <pink_mist> what the actual fuck?
[22:55:20 CET] <saml> is there scripting for ffmpeg?
[22:55:48 CET] <saml> ffmpeg cli only support statically building filter graph once, right?
[00:00:00 CET] --- Sat Dec  1 2018