[Ffmpeg-devel-irc] ffmpeg.log.20150831

[burek]

[00:10:28 CEST] <pisto> is there any container that allows me to store a timestamp for each frame, so that the time deltas can vary continuously?
[00:11:25 CEST] <pisto> basically I'd like to have a sequence of stills played at the same velocity of shooting
[00:21:13 CEST] <DHE> mkv supports variable framerate...
[00:21:42 CEST] <DHE> so does mpeg-ts but that's mainly used in specific situations that calls for it..
[00:26:09 CEST] <Chocolate_Chip> What is a good, lossless, free/libre video codedc?
[00:26:38 CEST] <Chocolate_Chip> I wanted to try webm, but my friend said it is not designed for quality, and is more lossy than ogv
[00:27:26 CEST] <durandal_1707> ffv1, huffyuv, ffvhuff
[00:27:48 CEST] <durandal_1707> webm is format
[00:28:02 CEST] <JEEB> and if you want to use it with proprietary stuff, ut video (which has plugins for most multimedia frameworks)
[00:29:43 CEST] <Chocolate_Chip> I meant format
[00:32:57 CEST] <c_14> matroska or nut, depending on how much support you want/need
[00:33:10 CEST] <Chocolate_Chip> So mkv>
[00:33:13 CEST] <Chocolate_Chip> Ok.
[00:33:28 CEST] <Chocolate_Chip> How do I modify my command to convert to that
[00:33:31 CEST] <Chocolate_Chip> I have this:
[00:33:31 CEST] <Chocolate_Chip>  ffmpeg -i /home/choco/Downloads/Bitter.mp4 -qmin 25 -qmax 35 Movie.webm
[00:33:48 CEST] <Chocolate_Chip> My friend also gave me that command
[00:34:08 CEST] <c_14> Just change the webm to mkv ?
[00:34:12 CEST] <c_14> That's not lossless though.
[00:34:14 CEST] <Chocolate_Chip> That's it?
[00:34:15 CEST] <Chocolate_Chip> ok
[00:34:17 CEST] <Chocolate_Chip> oh
[00:34:21 CEST] <c_14> and get rid of the qmin/qmax
[00:34:30 CEST] <Chocolate_Chip> What is lossless?
[00:34:36 CEST] <Chocolate_Chip> what do they do
[00:34:44 CEST] <c_14> Assuming your build is built with libx264 -qp 0
[00:34:55 CEST] <c_14> or just use -codec copy
[00:35:04 CEST] <c_14> It doesn't look like you're doing anything that needs reencoding
[00:35:24 CEST] <Chocolate_Chip> Ok. But you said that mkv is lossy.
[00:35:40 CEST] <c_14> mkv is a format, a format cannot be lossy
[00:35:45 CEST] <iive> lossless means compressing like rar. small compression but data stays absolutely the same.
[00:35:58 CEST] <Chocolate_Chip> <c_14> Just change the webm to mkv ?
[00:35:59 CEST] <Chocolate_Chip> <c_14> That's not lossless though.
[00:36:17 CEST] <c_14> Because ffmpeg will default to using libx264 with crf 23 for the conversion
[00:36:23 CEST] <c_14> Meaning it will reencode the video using a lossy codec.
[00:36:26 CEST] <iive> yes. you can put different video/audio codecs in same format.
[00:36:39 CEST] <Chocolate_Chip> is it possible to just download the video into an mkv, with a lossless codec?
[00:36:46 CEST] <Chocolate_Chip> Through ffmpeg
[00:36:53 CEST] <iive> everything is possible.
[00:37:02 CEST] <iive> lossless however is huge as filesize.
[00:37:08 CEST] <iive> bigger than blu-ray
[00:37:17 CEST] <Chocolate_Chip> hmm
[00:37:36 CEST] <c_14> Unless you just use -c:v copy to copy the video without changing it. It won't be "lossless video" but it will be identical to the source
[00:37:47 CEST] <iive> you just want good quality.
[00:37:52 CEST] <Chocolate_Chip> yes
[00:38:23 CEST] <Chocolate_Chip> Good quality, and a Free/Libre format
[00:41:19 CEST] <c_14> Does it have to be a Free/Libre codec as well? Or is just the format enough.
[00:42:20 CEST] <JEEB> what do you mean with a "free/libre" format?
[00:43:01 CEST] <JEEB> I mean, libx264 is GPL f.ex. and H.264 is a freely available standard for example. but it might require patent licensing depending on your juristiction
[00:43:29 CEST] <Chocolate_Chip> ok
[00:45:24 CEST] <JEEB> most people are calling something "free/libre" but actually mean "supposedly patent-free" (and funny enough those things that usually pop up in such discussions are actually LESS open than for example AVC/H.264 as far as standards go - if there even is a standard on it)
[01:07:35 CEST] <Polochon_street> okay, I'm still having leaks problem, it's driving me mad
[01:07:43 CEST] <Polochon_street> it's because of this function: https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/utils.c#L382-L402
[01:08:14 CEST] <Polochon_street> I think there's a problem with avformat_free(), can someone check? https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/utils.c#L3678-L3711
[01:10:36 CEST] <Polochon_street> it's freeing formatctx->internal, but not internal's raw_packet_buffer (https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/internal.h#L88-L89)
[01:54:34 CEST] <Polochon_street> okay. I finally got it. I already updated my situation twice in a row in the libav-user mailing, should I post the solution, or is it too much?
[03:06:45 CEST] <satazor> Hey guys, quick question: Does ffmpeg supports adding the ogg index (to improve seek performance) when encoding to a ogg file
[03:06:46 CEST] <satazor> ?
[04:57:18 CEST] <foreverska> I'm having trouble using ffmpeg to twitch.  It just comes up black.  Audio is perfect though.
[04:57:47 CEST] <foreverska> Anyone have any ideas?
[05:23:55 CEST] <foreverska> Figured it out.  thanks
[06:51:48 CEST] <MuffledSilence> Ive got a question regarding subtitles, when burning them onto a video file, is there a way to offset what time the subtitles start at? Im converting a file starting 13 minutes in but the subtitles essentially are 13 minutes late
[07:23:03 CEST] <Samus_Aran> what's the best approach to converting h.264 videos that are too CPU-intensive for my computer to play?  my system can generally handle 720p/30FPS/3Mbps or less, but chokes on 60FPS or higher-bitrate 720p.
[07:24:34 CEST] <Samus_Aran> I see -tune fastdecode, but not sure where the descriptions are for the tunings
[07:33:58 CEST] <kark> Hi hello i am new to ffmpeg . i would like to start the contribution on the project . so please help me how to start with.
[07:43:17 CEST] <durandal_1707> subscribe to ffmpeg-devel and join #ffmpeg-devel
[08:03:30 CEST] <TikityTik> I can't find anything on encoding with flv1
[08:03:42 CEST] <TikityTik> it's complaining either about -bufsize or -b:v
[08:08:42 CEST] <TikityTik> apparently using scale=-1:480 doesn't work
[08:08:48 CEST] <TikityTik> not sure why
[08:10:07 CEST] <TikityTik> is that a libvpx thing only?
[08:18:12 CEST] <Samus_Aran> does anyone know why -maxrate 3000k might be ignored?  the encode comes out at 5900k
[08:21:26 CEST] <Samus_Aran> using this line: ffmpeg -y -i in.mp4 -ss 00:00:10 -t 00:00:04 -codec:v libx264 -crf 16 -maxrate 3000k -bufsize 30000k -codec:a copy -async 1 out.mp4
[08:26:24 CEST] <Samus_Aran> the wiki says -maxrate is supposed to work with -crf, but it's always coming out above -maxrate
[08:26:48 CEST] <Samus_Aran> [libx264 @ 0x55d4232d29c0] kb/s:5986.55
[08:31:54 CEST] <TikityTik> Samus_Aran: you probably have to compromise more
[08:32:07 CEST] <TikityTik> as it depends on the resolution
[08:32:25 CEST] <TikityTik> and maxrate tends to not override crf too well i think
[08:36:27 CEST] <Samus_Aran> so how do I have it not ignore -maxrate?
[08:38:32 CEST] <Samus_Aran> it seems rather silly (insane?) to accept an option -maxrate that doesn't actually enforce any maximum rate.
[10:02:12 CEST] <Mavrik> Samus_Aran, your bufsize is so large
[10:02:22 CEST] <Mavrik> that you're letting the encoder overshoot bitrate for too much
[10:03:08 CEST] <JEEB> if libx264 doesn't warn you in the log, it has not overshot
[10:03:21 CEST] <JEEB> your calculations are then incorrect
[16:16:59 CEST] <t4nk043> Howdy yall
[16:17:19 CEST] <t4nk043> is it a bad idea to use the overlay filter when my videos have different frame rates?
[18:07:15 CEST] <berserker> Hi I am new here and would like to contribute to FFmpeg. Could someone please help me out.
[18:25:41 CEST] <durandal_1707> berserker: join #ffmpeg-devel
[18:27:40 CEST] <tommd> Fix bugs.
[18:50:01 CEST] <atomnuker> write a fourth prores encoder
[19:11:47 CEST] <Creative1> hi everyone
[19:12:15 CEST] <Creative1> i'm trying to find the android shared libraries for last version... so i can include on the project
[19:12:23 CEST] <Creative1> the usual arm7, x86, etc...
[19:12:58 CEST] <Creative1> i remember i saw them on the git, but i can't seem to find them any more, anyone knows?
[20:19:29 CEST] <ThuGie> Hi
[20:20:00 CEST] <durandal_1707> Hi
[20:20:51 CEST] <MaouKami> Question, does anybody know if there are plans for adding encoding of nsv ?
[20:20:59 CEST] <MaouKami> It seems currently only decoding is supported ?
[20:23:21 CEST] <durandal_1707> there are no plans only patches on ml
[20:23:52 CEST] <llogan> probably not. would likely need VP3/5/6 encoders first. patches welcome.
[20:24:20 CEST] <MaouKami> well it supports vp8 or as it seems to be called vpx
[20:24:22 CEST] <MaouKami> used in webm
[20:25:07 CEST] <llogan> i guess that helps, but i don't think there is much interest in nsv.
[20:25:27 CEST] <MaouKami> well thats true
[20:25:43 CEST] <MaouKami> right now i have to use nsvate, and a vp8 plugin
[20:26:00 CEST] <llogan> as durandal_1707 mentioned there are no real timelines, roadmaps, milestones. just whatever interests contributors and developers
[20:26:27 CEST] <MaouKami> yeah, well i thought it wont hurt me to ask :)
[20:27:06 CEST] <llogan> if you want to you could make a feature request on the bug tracker. and also post a bounty to it if you like.
[20:27:18 CEST] <llogan> or submit patches to ffmpeg-devel mailing list
[20:27:58 CEST] <MaouKami> the streaming and encoding is just a hobby so, if there is no plan its not really a problem :) just thought why not drop by and ask :p
[20:28:20 CEST] <MaouKami> i guess i be trying to add two-pass to the plugin :p
[20:28:55 CEST] <durandal_1707> nsvate is open source?
[20:29:14 CEST] <MaouKami> no its not but a sample plugin for vp8 is
[20:29:21 CEST] <MaouKami> as nsvate loads plugins
[20:29:55 CEST] <MaouKami> it simply loads the libvpx and uses that
[20:30:11 CEST] <MaouKami> so i guess vp9 is possible as well, not sure if there are players that do nsv with vp9 though
[20:31:52 CEST] <MaouKami> am i allowed to post links i can link the plugin example for vp8
[20:32:00 CEST] <llogan> sure
[20:32:46 CEST] <MaouKami> http://comserver.googlecode.com/svn/trunk/demo/comDemo/coder/
[20:32:55 CEST] <MaouKami> not made by me just to be clear
[00:00:00 CEST] --- Tue Sep  1 2015