[Ffmpeg-devel-irc] ffmpeg.log.20131123

burek burek021 at gmail.com
Sun Nov 24 02:05:01 CET 2013


[03:55] <ensoe> ffmpeg -f alsa -ac 2 -i hw:0,0 -f x11grab -r 30 -s $(xwininfo -root | grep 'geometry' | awk '{print $2;}') -i :0.0 -acodec pcm_s16le -vcodec libx264 -preset ultrafast -crf 0 -threads 0 -y desktop0recording.avi
[03:55] <ensoe> how would I have to adjust this to actually only capture a certain section of my screen? I'd like to be able to draw a frame where it should record. Can that be done?
[08:40] <easyfab> I'd like to create a batch under windows with ffmpeg like this : http://pastebin.com/KLvgDgxC  but with scale.
[08:41] <easyfab> Is it possible to do something like : if iw > 720p do scale else don't ?
[08:42] <easyfab> ih > 720p
[08:44] <easyfab> So to scale only if the file iput height is > 720p ?
[08:55] <ubitux> easyfab: -vf scale='max(iw,720):-1' ?
[08:56] <ubitux> -vf "scale='max(iw,720)':-1"
[08:56] <ubitux> actually, min()
[09:12] <easyfab> ubitux: thanks  min() is what I needed ->  -vf scale="trunc(oh*a/2)*2:'min(ih,720)'"
[18:19] <rexbron> Does anyone know how to get ffmpeg to copy over all metadata from a Broadcase Wave file when trimming. Timecode from a Sound Devices 664T got stripped out. It show up in ffprobe but -codec:a copy only seems to carry over some of it
[19:21] <intracube> hi, does anyone know how to write custom metadata with ffmpeg/libx264?
[19:22] <intracube> I'm trying to add some information that's not carried over from a set of video files when transcoding
[19:22] <intracube> specifically adding 'Scan order' 'Top Field First'
[19:22] <sacarasc> -metadata cheese="yes please"
[19:22] <sacarasc> I think you have to do a -metadata for each piece you want to add.
[19:23] <intracube> ah kewl, thanks sacarasc :)
[19:24] <intracube> hmm, that doesn't seem to work
[19:25] <intracube> does it need to be associated with a particular stream?
[19:25] <intracube> (I'm looking at what mediainfo is reporting back)
[19:39] <intracube> oh, so ffmpeg doesn't support all key=value options: http://multimedia.cx/eggs/supplying-ffmpeg-with-metadata/
[19:43] <saste> the muxer should complain in case of invalid metadata
[19:43] <saste> i suppose it's easier to write a blog entry than a patch :)
[19:44] <intracube> saste: it's failing silently
[19:44] <intracube> and different containers support a different range of key=value pairs
[19:45] <saste> intracube, patch/report welcome
[19:45] <intracube> ;P
[19:45] <intracube> well, I can report at least :)
[19:46] <Logicgate> hey guys, if I was to read a video file via text to get the data (h264 encoded AAC mp4), what charset should I use not to lose any data
[19:46] <Logicgate> Im basically trying to upload the file via an http protocol, reading the contents of the mp4 via php and ajaxing it over to an S3 bucket
[19:46] <Logicgate> I seem to fail to find the right charset
[19:49] <saste> Logicgate, why are you abusing HTTP to send data as text, in the first place?
[19:55] <LithosLaptop> Logicgate: it doesn't have to be text
[19:55] <LithosLaptop> HTTP can handle binary
[19:56] <LithosLaptop> but if you MUST send it with text then all you have to do is Base64 the data as text
[19:57] <LithosLaptop> -*Base64 encode
[19:58] <LithosLaptop> on the other side just Base64 decode the text to get the binary data again
[19:59] <LithosLaptop> charset won't matter
[19:59] <LithosLaptop> ASCII will work
[00:00] --- Sun Nov 24 2013


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