[Ffmpeg-devel-irc] ffmpeg.log.20140615

[burek]

[00:01] <waressea1cher2> now its less messy
[00:01] <waressea1cher2> at first I was shocked
[00:02] <llogan> yeah, and using testsrc as an input makes it a little more verbose
[00:02] <llogan> althought easy to test
[00:03] <waressea1cher2> c_14: that web page says "trac powered", maybe you haven't made any mistake ?
[00:04] <llogan> basically all you need are: pad (or some other method to make a "canvas"), setpts, and overlay. and additional other filters for audio depending on what you want to do
[00:05] <c_14> trac is just the wiki software. >Trac is an enhanced wiki and issue tracking system for software development projects.
[00:08] <waressea1cher2> its always better to use one ffmpeg command with long filter chain rather than few with one filter in each ? like "ffmpeg -i input -vf filter1,filter2 output" is better then: "ffmpeg -i input -vf filter1 output1" and "ffmpeg -i output1 -vf filter2 output2" ?
[00:09] <c_14> better is subjective, but you will spare yourself a lot of encoding and potential quality loss (depending on the codec used)
[00:43] <smo_> hi
[00:44] <smo_> i m trying the libx265 encoder and get lot of non-existing PPS (i try to open files with gst-launch and lide265)
[00:44] <smo_> can do something for this ?
[04:02] <causasui> can ffmpeg segment an audio file into files of an arbitrary length? or would I have to loop through the time stamps?
[04:02] <causasui> e.g. take this 7 hour mp3 and segment it into 10 minute chunks
[04:03] <c_14> look at the segment muxer
[04:09] <_genuser_> dang, ffmpeg encoding same file seems to take longer.
[04:09] <_genuser_> proably because normally I see it doing pass 1 really fast and second pass. this one seems to be reporting time much slower and not showing which pass it's on.
[08:39] <isomorphismes> I'm following the Ubuntu ffmpeg compilation instructions
[08:39] <isomorphismes> but at the end I got some errors on the ffmpeg make and make install.
[08:39] <isomorphismes> There's no ~/bin/ffmpeg, probably as a result.
[08:44] <isomorphismes> ok hold on
[08:44] <isomorphismes> dpaste.de/UfTj
[08:46] <isomorphismes> dpaste.de/0M7H is the longest i can get
[08:47] <sacarasc> I have never seen strip say "blah is not a normal file" before. :|
[09:03] <Fyr> guys! I run the following command:
[09:03] <Fyr> ffmpeg -i 1.wmv -vcodec h264 -pass 1 -passlogfile n1 -threads 12 -psnr -vstats -profile:v baseline -preset veryslow -an -y -crf 18 -f rawvideo /dev/null && ffmpeg -i 1.wmv -vcodec h264 -pass 2 -passlogfile n1 -threads 12 -psnr -vstats -profile:v baseline -preset veryslow -crf 18 -acodec libfdk_aac -aq 8 -y 1.mp4
[09:03] <causasui> gesundheit
[09:03] <Fyr> and get error: wrong bitrate, width, height or something else.
[09:04] <Fyr> I always get this error when I try to run second pass.
[09:05] <Fyr> I changed -crf on -b, tried -an, removed one-by-one presets, profiles.
[09:05] <Fyr> recompiled fmpeg.
[09:05] <Fyr> anyway, the same error.
[09:18] <isomorphismes> sacarasc: what do you think that means?
[09:18] <sacarasc> I don't know, you're going to have to wait for someone who might know.
[09:18] <isomorphismes> ok cool no problem
[09:18] <isomorphismes> TIA
[09:21] <Fyr> fine
[09:21] <Fyr> any ideas how to solve it?
[09:21] <causasui> pastebin.com sux :\
[09:39] <sacarasc> Fyr: Can we have your paste?
[09:42] <Fyr> how to make ffmpeg output to a file?
[09:42] <sacarasc> Which OS?
[09:42] <Fyr> I have a big part of output cut because of tmux.
[09:42] <Fyr> Scientific Linux 6.3
[09:43] <sacarasc> ffmpeg blah &> cheese.txt
[09:43] <Fyr> ok
[09:44] <a141982112> when I press t while playing video subtitle switch from actual stream to -1, what does -1 stream mean
[09:44] <a141982112> i am using ffplay to play
[09:52] <Fyr> sacarasc:
[09:52] <Fyr> http://pastebin.com/isTujsP3
[09:55] <sacarasc> Could be: [libx264 @ 0x3442f40] constant rate-factor is incompatible with 2pass.
[09:55] <sacarasc> Try using 1 pass or a bitrate.
[09:56] <Fyr> is crf constant-rate factor?
[09:56] <sacarasc> Yeah.
[09:57] <Fyr> how to choose bitrate?
[09:58] <Fyr> the file has vbr with peak 10Mbps and average 8Mbps.
[09:58] <sacarasc> Why do you want to do 2 pass?
[09:58] <Fyr> it decrease filesize.
[09:58] <Fyr> it means better compression.
[09:59] <sacarasc> Do you have a specific size you want?
[09:59] <Fyr> no
[09:59] <Fyr> I need higher quality and lower file size.
[10:00] <sacarasc> Then just use crf and single pass. Run a test of a high action scene and a low action scene, find the crf number you want and then use that for the whole file. (Or, just go for crf 20 straight off.)
[10:00] <Fyr> how to find crf number?
[10:01] <sacarasc> Higher is worse quality, but lower size, lower is higher quality but larger size.
[10:01] <Fyr> so, how to find the proper value?
[10:02] <sacarasc> ffmpeg -i blah.wmv -ss 10:00 -t 1:00 -an -c:v libx264 -crf X output.mp4
[10:03] <sacarasc> Do that with different values of X until you find the highest number you want.
[10:03] <Fyr> and how to use psnr for it?
[10:03] <Fyr> and analyze vstats?
[10:04] <sacarasc> Just add them in.
[10:23] <Fyr> PSNR Mean Y:47.956 U:51.159 V:51.581 Avg:48.823 Global:48.803 kb/s:5210.03
[10:24] <Mavrik> don't use PSNR to measure video quality ffs -_-
[10:26] <Fyr> how to measure video quality?
[10:26] <sacarasc> Eyes.
[10:27] <Mavrik> Eyes.
[10:27] <Fyr> I have a bad squint and dyslexia.
[10:28] <Mavrik> measuring quality of video produced by codec with psycho-visual optimizations is totally wrong
[14:24] <Fjorgynn> hey
[14:24] <sacarasc> Hello.
[14:24] <Fjorgynn> I did ffmpeg -i hey.wav to hey.flac
[14:24] <Fjorgynn> but it lowered the bitrate from 700 kbps to 250 kbps
[14:25] <Fjorgynn> why
[14:25] <sacarasc> Because FLAC is lossless *COMPRESSION*. It makes wave files smaller.
[14:25] <sacarasc> Without losing any of the quality.
[14:25] <Fjorgynn> ok
[14:29] <Fjorgynn> I am digitizing my music casettes and think it might be a good idea to save the lossless to, if mp3 isn't the right way for them
[14:29] <Fjorgynn> or if I want to increase volume and such
[18:50] <luc4> Hello! Anyone who can advice on a way to resample a video file to reduce the fps?
[18:50] <luc4> Keeping quality unaltered I mean.
[18:56] <c_14> I'm not sure you can change the fps without reencoding the video, and if you are using a lossy codec you will lose quality even if it isn't noticeable.
[18:57] <luc4> c_14: ah ok, I see that probably by adding -vcodec it actually re-encodes and sets the frame rate. Thanks.
[20:55] <waressearcher2> I found that page http://wjwoodrow.wordpress.com/2013/11/22/adjusting-video-contrast-brightness-saturation-and-color-balance-with-ffmpeg it suggest to use "-vf mp=eq2=gamma:contrast:brightness:saturation:rg:gg:bg:weight" for changing "gamma,contrast,brightness,saturation" is it right way ? because it uses "mp" for mplayer
[20:58] <llogan> waressearcher2: that's one method, I suppose. there are many video filters available that can do similar stuff like the "curves" filter
[23:47] <needmorespeed1> I've got frames and playback. Does ffmpeg have any queueing feature like a decoded picture buffer (DPB)?
[00:00] --- Mon Jun 16 2014