[Ffmpeg-devel-irc] ffmpeg.log.20141108

burek burek021 at gmail.com
Sun Nov 9 02:05:01 CET 2014


[00:02] <c_14> hmm, looks like burning in dvdsub subtitles is broken...
[00:54] <llogan> c_14: is it a regression?
[00:55] <c_14> Hmm, good question. Let me finish what I'm doing and then I'll do a git bisect to see if I can find out.
[02:26] <c_14> Hmm, can't seem to find a version where it works.
[02:27] <c_14> It does seem to work if I use the idx file though.
[02:34] <c_14> Ye, with the idx seeking and everything else seems to work as well.
[03:00] <c_14> Not sure if that's a bug or not though. I mean, technically the idx is part of the "subtitle stream" as such if I understand correctly, but you can watch using only the sub...
[04:38] <moonman_> Question on technical feasibility of AVC lossless crop, regardless of whether ffmpeg supports it http://pastebin.com/puVkC5ji
[08:40] <Kip> what is the usual extension for uncompressed video?
[08:53] <relaxed> .y4m or .yuv
[08:59] <Kip> thank you
[12:58] Action: DelphiWorld ugh emilsedgh
[12:59] <emilsedgh> \o/
[15:42] <Hebi> hello, is it possible to remove embedded chapter marks in mp4 files? thanks in advance
[15:43] <c_14> -map_chapters -0 might do it
[15:45] <Hebi> alright
[15:46] <Hebi> so {ffmpeg -i in.mp4 -map_chapters -0 -c copy out.mp4} will do it?
[15:47] <c_14> Maybe, probably, hopefully.
[15:47] <c_14> Never tried it, but it sounds like it might.
[15:52] <Hebi> alright thanks, will report back lel
[16:04] <ChenFang> anyone?
[16:06] <ChenFang> I'm writing a demuxer for Android with ffmpeg for mpeg ts files. And I found a problem that I cannot read the first keyframe after start or seek. anyone known why?
[16:45] <danielballestero> hello
[16:45] <danielballestero> i would like make a question
[16:46] <danielballestero> i wanna try conect a wii u gamepad with a raspberry pi (using the raspi hardware encoder)
[16:46] <danielballestero> but i am not sure if i can
[16:46] <danielballestero> (the developers have create a patch for software x264 codec ffmpeg code)
[16:48] <JEEB> only if the raspi hw encoder creates streams that are compatible
[16:49] <danielballestero> i dont know where ask this : here or searching a rasperry pi chat (i am searching now) because on libdrc seem no many activity
[16:49] <danielballestero> hello
[16:49] <danielballestero> yes ,this is my problem
[16:49] <danielballestero> ( i know no many about video encoder,only basics)
[16:50] <danielballestero> how can i know (and how config raspi hw ) be able to create this kind of streams
[16:50] <danielballestero> (can i post here links??
[16:52] <danielballestero> this is how wii u gamepad "understand" the streams:
[16:52] <danielballestero> http://libdrc.org/docs/re/sc-vstrm.html
[16:53] <danielballestero> and they use ffmpeg for building the lib
[16:53] <danielballestero> http://libdrc.org/docs/installation.html#system-requirements
[16:54] <danielballestero> they created a patch for ffmpeg (but software version)
[17:00] <waressearcher2> I want to dump audio from mp4 file to uncompressed fomat to edit it in audacity, what should I use as "-acodec" option ? -acodec wav ?
[17:01] <JEEB> just set output file name to something-dot-wav
[17:01] <waressearcher2> will that "wav" be losless format ?
[17:02] <waressearcher2> I want to conserve all audio   quality
[17:05] <waressearcher2> I presume yues
[17:09] <iive> .wav is audio only .avi . it is mostly used for PCM that is raw format, so it is lossless
[20:08] <BlackDream> Hello, i read this https://trac.ffmpeg.org/wiki/Creating%20multiple%20outputs on how to creadte multiple outputs and it worked. However i want to use duplicate output when i transcode so that all the outputs so that the transcode will be done once. I read that this can be made using the -f tee
[20:08] <BlackDream> however, i'm currently using -f segment and i have no idea how to write it in the tee format
[20:10] <BlackDream> "The tee pseudo-muxer was added to ffmpeg on 2013-02-03, and allows you to duplicate the output to multiple files with a single instance"
[20:10] <BlackDream> it says to multiple files, so it can't be done in segment format?
[20:12] <blippyp> what do you mean by -f segment?
[20:12] <rjp421> tee mux?
[20:12] <BlackDream> ok let's say that i'm using this:
[20:12] <c_14> BlackDream: -f tee "[segment]filename|otherfoo" <- should do it afaik
[20:12] <BlackDream> ffmpeg -i "url" -acodec copy -f segment -segment_list out.list out%03d.nut
[20:13] <BlackDream> yeah but where do i specify the segment time and list?
[20:14] <BlackDream> Let me say it again. I'm currently using -f segment to output the same FFmpeg INPUT to MPEGTS & FLV. So we have double output here.
[20:15] <BlackDream> However, if i want to transcode the input stream, how i can write the command so that the encode will be made with one instance of ffmpeg and output again to segments in mpegts & flv
[20:15] <c_14> eh, [f=segment:segment_list=out.list:other_option=foobar]
[20:15] <c_14> I think that should work.
[20:15] <c_14> Didn't test though.
[20:15] <BlackDream> ok let me try
[20:16] <BlackDream> Slave '[f=segment:segment_list=out.list]': error writing header: Muxer not found
[20:18] <c_14> What's your complete command line?
[20:19] <blippyp> maybe you don't use the =out.list, try replacing the '=' with a space??
[20:20] <BlackDream> ffmpeg -i "URL" -codec copy -f segment -segment_format mpegts -segment_list mpegts.list -segment_time 10 out%03d.ts -codec copy -f segment -segment_format flv -segment_list flv.list -segment_time 10 out%03d.flv
[20:20] <c_14> eh, the new one
[20:21] <c_14> The one with -f tee
[20:21] <BlackDream> and in this example, i also use -codec copy twice, so how i can do the copy/transcode using it only one time but output it using duplicate output ;p
[20:21] <BlackDream> ah
[20:21] <BlackDream> sorry
[20:21] <BlackDream> i actually didn't make it so i don't know
[20:22] <c_14> What command were you using when ffmpeg gave you the Slave error.
[20:23] <BlackDream> ffmpeg -i "URL" -codec copy -f tee -map 0 "[f=segment:segment_list=out.list]"
[20:27] <c_14> try: ffmpeg -i URL -codec copy -f tee -map 0 "[f=segment:segment_list=out.list:segment_format=mpegts:segment_time=10]out%03d.ts|[f=segment:segment_format=flv:segment_list=flv.list:segment_time=10]out%03d.flv"
[20:27] <BlackDream> wow you made it
[20:27] <BlackDream> <3 love you
[20:50] <skyman> nick sky3
[22:40] <rsully> Can anyone point me in the right direction? I'm trying to figure out the best way to utilize both processors / all cores to encode to x264 (from a lossy source mpg).
[22:42] <sacarasc> rsully: With recent ffmpegs, it should do that.
[22:42] <sacarasc> Automagically.
[22:43] <rsully> I last tested using default install from ubuntu 12.04. Is there an official repo for ubuntu to get the most up to date version?
[22:44] <sacarasc> Ubuntu doesn't even ship ffmpeg, it ships a fork called libav. If you want ffmpeg, try looking here: https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu (or a couple of links in a second). If you want to use libav, go to #libav.
[22:44] <rsully> sacarasc ah that explains the warning i got
[22:47] <rsully> any pro/con of ubuntu multimedia ppa vs jon's ppa?
[22:47] <sacarasc> I've never used either, so can't comment.
[22:57] <rsully> looks like jon's ppa is super out of date
[22:58] <rsully> and the multimedia ppa is on 2.4.2
[23:03] <rsully> I'll just grab a static build for now and figure it out later
[23:07] <Q11> Good afternoon, I'm trying to reencode/copy a part of movie that downloaded in torrent, thus having just a little piece of it. The idea is to download some continous pieces from the middle of the torrent, maybe with the header (mp4) and "fix" them with ffmpeg, but I couldn't make it work... I would appreciate any ideas :)
[23:16] <rsully> Q11 so your goal is to only download say 10% of the middle of the torrent + 5% of the beginning with the header and then use that to reconstruct the 10% middle to be viewable?
[23:23] <Hello71> Q11: basically you want seekable torrents
[23:34] <rsully> Hello71 ooh thats a neat way to look at it. but I think he is looking at it from the perspective of only wanting a specific timestamp of the video so he can save bandwidth
[23:41] <Q11> Hello71: What do you mean? If I do calculate the part of the torrent I want to download, it still most likely starts in middle of something, which causes to ffmpeg to fail, as far as I can judge...
[23:55] <Q11> Thanks all, g2g...
[00:00] --- Sun Nov  9 2014


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