[Ffmpeg-devel-irc] ffmpeg.log.20131011

burek burek021 at gmail.com
Sat Oct 12 02:05:01 CEST 2013


[03:09] <Zarxrax> how can i reencode a video using ffmpeg, and take softsubtitles and hardcode them into the new encode
[03:09] <Zarxrax> im trying to avoid the extra step of first extracting the subtitle stream
[03:27] <mark4o> Zarxrax: ffmpeg -i in.mp4 -vf subtitles=sub.srt out.mp4
[03:33] <Samus_Aran> is there some way to limit the max bitrate when using crf encoding?  I tried -maxrate 15m, but it still went up to 80Mbps
[03:33] <Samus_Aran> or is the only way to raise the crf?
[03:34] <mark4o> Samus_Aran: you need both -maxrate and -bufsize
[03:38] <Zarxrax> mark4o: im referring to using the subtitle file that is already present in the video file. is that the way to do it?
[03:41] <mark4o> Zarxrax: oh sorry, you want to avoid extracting them to a file; hmm, I don't know that there is any way to do that
[03:42] <Zarxrax> well, i guess i can extract them then
[03:42] <Zarxrax> im just really lazy
[03:44] <Samus_Aran> mark4o: how do I choose the buffer size?
[03:45] <Samus_Aran> I'm encoding PNG animation frames, 1080p/30
[03:48] <mark4o> Samus_Aran: -maxrate is the maximum rate over some period, specified by -bufsize.  Wherever you got the -maxrate you are using should also specify a size or duration.
[03:49] <Samus_Aran> I just don't want the maximum bitrate to spike beyond 15Mbps, as my laptop is slow
[03:52] <mark4o> Samus_Aran: try -bufsize 4M
[04:09] <Samus_Aran> mark4o: will try, thanks.
[04:18] <ExceptionlCatch> hello, i'm new and still finding out about max_analyze_duration reached
[04:18] <ExceptionlCatch> it happens when playing the file in ffplay and i can't tell whether its benign or a problem
[04:19] <ExceptionlCatch> i tried convertnig the wav to an mp3 but playing the mp3 still has that message
[05:32] <Zeranoe> Does ffmpeg's http protocol require a server to stream? I know VLC offers a HTTP streaming option, does that run a server too?
[13:36] <burek> can anyone suggest what could be wrong with this: http://pastebin.com/aVVzyYzU
[13:38] <durandal_1707> why is - used for -i ?
[13:53] <ubitux> burek: -f h264 ?
[13:53] <ubitux> durandal_1707: stdin
[13:53] <ubitux> ah wait ok
[13:53] <ubitux> burek: -r as output option i guess
[14:02] <burek> i guess -r specifies the input frame rate
[14:02] <burek> since it's a stdin
[14:03] <burek> wait http://ffmpeg.gusari.org/viewtopic.php?f=16&t=1100&p=2727
[14:03] <burek> that's the original post
[14:03] <burek> there is an example without -r at all
[14:03] <burek> experiencing the same issue
[14:20] <burek> I can't even understand what does this guy talk about http://ffmpeg.gusari.org/viewtopic.php?f=16&t=1092 :(
[14:43] <ubitux> burek: i see -r 25 as input option as well here
[14:43] <ubitux> i think it's supposed to be set as output optoin
[14:43] <ubitux> (or not at all?)
[15:30] <burek> ubitux, in his 1st cmd line, there was no -r for input
[15:30] <burek> pi at raspberrypi ~/ffmpeg $ raspivid -vf -t 0 -w 450 -h 200 -fps 25 -b 2000000 -o - | ffmpeg -i - -c:v libx264 -vcodec copy -f h264 -loglevel debug test.mp4
[15:30] <burek> but he still got "[h264 demuxer @ 0x31be320] Unable to parse option value "25" as video rate"
[15:47] <ubitux> burek: the error wasn't the same afaict
[16:20] <fling> I have a bunch of videos from a security cam.
[16:20] <fling> I want to only keep parts of video with movement
[16:28] <durandal_1707> fling: so you need some kind of movement detection filter?
[16:29] <fling> durandal_1707: yes ;P
[16:29] <durandal_1707> there is no such thing (yet) in libavfilter
[16:29] <fling> durandal_1707: I may convert everything to images and just drop similar frames
[16:29] <fling> durandal_1707: but I want to keep sound
[16:41] <willvarfar> can ffmpeg transcode a video from an mp4 file passed over stdin before the moov is received?
[16:41] <durandal_1707> no
[16:42] <willvarfar> what general approaches are there to consuming mp4 that hasn't yet got the moov?
[16:43] <ubitux> chunked mp4
[16:43] <ubitux> ah, as input
[16:43] <ubitux> you can't
[16:44] <willvarfar> hmm tricky then.  I can get an android phone to record h264 in mp4 and send it straight to my server live,
[16:45] <willvarfar> but on the server I can't do anything with it until its stopped anyway, making it not live after all.
[16:46] <ubitux> send chunked mp4
[16:46] <ubitux> or just use another container
[16:48] <willvarfar> yes on android the pick seems limited
[16:53] <willvarfar> thx.
[18:17] <diroots> hi all
[19:21] <xlinkz0> can i make ffserver stream copy from feed to stream?
[19:25] <ezekiel> I'm not entirely sure what you're asking, but I'll guess - ffserver will try to do as little transcoding as possible, if I recall correctly
[19:25] <ezekiel> so if your OUTPUT parameters are similar/same to your input feed, then it's not going to transcode
[19:25] <xlinkz0> i don't want it to transcode at all
[19:26] <xlinkz0> ok
[22:16] <Mista_D> Trying to read a redirected STD and ERR out from a file. tail -f is working, but tail with grep and cut are not.
[23:48] <alesan> hi I have some full HD movies 60fps that I would like to reduce to 1280x710 and 30fps, keeping the audio and if possible other parameters similar
[23:49] <alesan> so far I've found ffmpeg -i $i -vf scale=1280:-1 small/$i
[00:00] --- Sat Oct 12 2013


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