[Ffmpeg-devel-irc] ffmpeg.log.20170317

burek burek021 at gmail.com
Sat Mar 18 03:05:01 EET 2017


[00:00:04 CET] <iive> oh, he said it is fragmented above ...
[00:00:48 CET] <iive> can ffmpeg muxer create fragmented mp4? it does support hls,so i guess it does.
[00:00:49 CET] <JEEB> which is why I said what I said
[00:00:56 CET] <iive> yeh.
[00:01:01 CET] <JEEB> yes, movenc.c can do fragmented isobmff
[00:01:04 CET] <JEEB> I use it daily
[00:01:31 CET] <JEEB> also libavformat has a dashenc.c for MPEG DASH which utilizes movenc's fragmented ISOBMFF muxing capabilities
[00:02:46 CET] <IntruderSRB> btw. I've finally got my hands on properly encrypted HLS/fMP4 combination that works natively in Safari
[00:03:05 CET] <IntruderSRB> now I'm inspecting nal units produced by them and same nal units produced by mine encryptor...
[00:03:14 CET] <IntruderSRB> hex is my friend...
[00:03:18 CET] <JEEB> iive: -movflags frag_keyframe for on-IRAP fragmentation :P
[00:03:33 CET] <JEEB> IntruderSRB: yes binary diff tools are love
[00:03:52 CET] <IntruderSRB> I came from web development world .... we had postman and JSON
[00:03:52 CET] <JEEB> vbindiff is what I used when making the Ut Video encoder when debugging failing test cases :3
[00:04:23 CET] <IntruderSRB> got Hex Fiend .... does the job right
[00:04:33 CET] <IntruderSRB> not many features but all I need is compare :D
[00:07:00 CET] <JEEB> ok, dropbox can now officially fuck off
[00:07:08 CET] <JEEB> my old straight links no longer work >:|
[00:07:44 CET] <JEEB> so I have no reason to host those things there any more (to keep old links alive)
[00:08:29 CET] <IntruderSRB> lol
[01:16:40 CET] <Sparkyish> Looking for help with multiple audio channels. I need to create a file that contains audio from the first 4 mono channels on an SDI/HDMI input. The output shouldn't have any audio manipulation (the kind which happens when using a 5.1 surround sound profile). Any direction? I've tried reading about pan, but I can't figure out a good command to make this work.
[01:18:07 CET] <JEEB> I think you only need audio channel mapping
[01:21:16 CET] <Sparkyish> JEEB, doesn't mapping create separate streams? If I understand the terminology correctly, I need a single stream with 4 active channels so that they all play at once (via SDI output)
[01:22:07 CET] <JEEB> Sparkyish: -map yes, but I meant that there's a filter (the name of which I don't remember) which will let you select tracks and make one N channel track out of them
[01:53:03 CET] <Sparkyish> JEEB: could it be -ac:[stream specifier] that you are thinking of?
[01:54:47 CET] <IntruderSRB> btw. can someone confirm that ffmpeg -c copy copies exact copy of H264 nal units - it doesn't do Annex B conversion in the meantime
[01:54:48 CET] <IntruderSRB> ?
[02:09:55 CET] <IntruderSRB> hm ... -c copy with and without "-vbsf h264_mp4toannexb" produces same result
[02:10:21 CET] <IntruderSRB> should I assume that in mp4 it's really annexb or -c copy implicitly uses "-vbsf h264_mp4toannexb" anyway?
[02:24:07 CET] <iive> i could speculate that annex b is needed for fragments
[02:24:23 CET] <iive> aka, it copies each extradata headers inside the video bitstream
[02:24:51 CET] <iive> just a speculation...
[02:34:05 CET] <thebombzen> IntruderSRB: h264_mp4toannexb changes how the frames are packed. certain streaming formats like mpegts require a different sort of thing than mp4
[02:34:29 CET] <thebombzen> however, my best guess is that you're getting the same behavior because this bsf is auto-inserted where relevant
[02:34:40 CET] <thebombzen> so even if you don't specify -bsf:v it's still there
[02:34:56 CET] <IntruderSRB> thebombzen: yes - thing is I have an fmp4 that I need to inspect and ffmpeg -c copy I see annexB (bitstream)
[02:35:14 CET] <IntruderSRB> so I was wondering if it was already there or since I asked pure h264 ffmpeg added it anyway
[02:35:35 CET] <IntruderSRB> but yea ... it was inserted by ffmpeg ...
[02:36:27 CET] <IntruderSRB> weird thing is it addes leading_zero_8bits in front of any Access Delimiter NALU
[02:36:36 CET] <thebombzen> "Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw H.264 (muxer "h264") output formats." - The documentation.
[02:36:38 CET] <IntruderSRB> but doesn't add zero_byte in front of SPS and PPS
[02:36:47 CET] <thebombzen> other than that
[02:36:57 CET] <thebombzen> I can't really say anything b/c I don't exactly know how it works
[03:21:42 CET] <AnonBaiter> hi
[03:21:46 CET] <AnonBaiter> so, I have more samples from me
[03:29:48 CET] <jinihm> Has anyone tried installing ffmpeg with nvenc support on Jetson TX1? I definitely have Cuda installed but when I try to install ffmpeg, it says "ERROR: nvenc requrested, but not all dependencies are satisfied: cuda"
[03:45:22 CET] <jinihm> also it tries to compile some files like "window.h" that only exist on windows while my machine is ubuntu
[03:50:00 CET] <memeka> hi; i have 2 ffmpeg installs - one in /usr one in /usr/local; both using shared libs; but both /usr/bin/ffmpeg and /usr/local/bin/ffmpeg use the same shared libav libraries (from /usr/lib); is there a way to point /usr/local/bin/ffmpeg to /usr/local/lib/libav* without LD_LIBRARY_PATH?
[03:59:31 CET] <AnonBaiter> here is a sample
[03:59:31 CET] <AnonBaiter> https://www.sendspace.com/file/a586wg
[04:02:38 CET] <AnonBaiter> this sample was obtained from all three console versions(PS2, GC, XBOX) of Tiger Woods PGA Tour 2003.
[04:45:24 CET] <memeka> hi; how do i specify device output to ffplay? e.g. xv, opengl, ... ?
[04:52:20 CET] <memeka> anyone?
[05:09:04 CET] <AnonBaiter> hi
[12:06:44 CET] <Drazick> Hello. Anyone here?
[12:08:19 CET] <Drazick> I have new user question. What's the difference between `-r` and `-framerate` in general and in the context of creating videos from still images?
[14:20:08 CET] <faLUCE> hello, given rawH264EncodedVideo.h264,  how can I split it into multiple files (one file per frame) ?
[14:31:52 CET] <utack> is there a way for the "benchmark" mode to store minimum fps?
[14:31:55 CET] <utack> isntead of average
[15:50:45 CET] <nicomachus> hi all. I have about 50 video files (.mkv) that have multiple audio and multiple subtitle tracks embedded in the video. 3/4 audio are Russian and 1/2 subs are Russian, the other 1 of each is English. Can I use ffmpeg to re-encode them keeping only the english audio and sub tracks, without losing quality?
[15:51:53 CET] <DHE> yes, you can use -c copy and clever use of -map to select the english tracks
[15:52:26 CET] <nicomachus> I found some guides online about that but I wasnt sure about how it would work with multiple tracks
[15:54:42 CET] <nicomachus> and I'm guessing this will be a bit CPU intensive. :)
[15:54:44 CET] <DHE> when you use -map you're forcing your own selection of tracks rather than using ffmpeg's default selections. you'll have to include 3 - one for video, one for audio and one for subtitles.
[15:54:53 CET] <DHE> no. copying streams tends to be disk intensive
[15:55:31 CET] <nicomachus> ah. well disk is better than CPU when it comes to this HTPC. and I'm guessing it shouldn't be hard to set up a `for` loop to do it all in a batch?
[15:58:15 CET] <DHE> should be, as long as all the videos are about identical. all have a subtitle track available in english, all have an audio track available in english, etc.
[16:00:41 CET] <nicomachus> yea it's 5 seasons of a tv show. 10 episodes each. All from the same source.
[16:15:09 CET] <nicomachus> ok I'm not sure about this -map option. If I have multiple audio streams, and I only want to keep the third one, do I do `-map 0:0:1:0` or `-map 0:3`?
[16:16:01 CET] <nicomachus> well, I guess it counts subs as "streams" too, so I want to keep stream 3 and 6.
[16:18:33 CET] <DHE> read the manual. there are more complex matches, including language selection.
[16:18:53 CET] <DHE> or if "ffprobe" always shows the streams in the same order, then you can use "0:3" notation as indicated
[16:22:04 CET] <nicomachus> yea I'm looking at the man page, the -map section just isn't all that clear for me, I guess. especially when it comes to working with multiple streams
[16:26:38 CET] <nicomachus> yep, I did something wrong... Kept both audio and sub tracks I wanted, but didn't keep video. Lol
[16:26:54 CET] <nicomachus> whoops... round 2
[19:33:26 CET] <feliwir> hey, can someone explain this function simplified: https://github.com/FFmpeg/FFmpeg/blob/967feea5ebb744dce97ab327d33502b43fca0c7f/libavcodec/vp6.c#L393
[19:33:50 CET] <feliwir> i know how huffman works, the VLC table stuff that ffmpeg is doing there is confusing me a lot
[19:34:32 CET] <feliwir> also when the huffman tree is created there is some VLC stuff going on (which is a complete undocumented part of ffmpeg...)
[19:35:07 CET] <atomnuker> feliwir: ask BBB on #ffmpeg-devel
[19:35:46 CET] <feliwir> okay, i'll try
[20:34:35 CET] <obamoose> hello
[20:34:41 CET] <obamoose> how do I turn this into an infinite loop?
[20:34:47 CET] <obamoose> find /home/me/cgn -name "*.mp4" | xargs -I $ ffmpeg -y -re -i $ -vcodec libx264 -preset veryfast -maxrate 3000k -bufsize 6000k -pix_fmt yuv420p -g 50 -c:a aac -b:a 160k -ac 2 -ar 44100 -f flv rtmp://a.rtmp.youtube.com/live2/my_id
[20:35:06 CET] <obamoose> http://pastebin.com/dNFKjLfW
[20:35:20 CET] <furq> by not using xargs for starters
[20:35:58 CET] <furq> https://trac.ffmpeg.org/wiki/Concatenate
[20:36:15 CET] <furq> you probably want the demuxer or the filter if you want the client to not drop out at file boundaries
[20:36:32 CET] <furq> as for looping it forever, you probably want the loop filter
[20:36:34 CET] <furq> !filter loop
[20:36:34 CET] <nfobot> furq: http://ffmpeg.org/ffmpeg-filters.html#loop
[20:39:47 CET] <obamoose> this is a lot of information
[20:39:48 CET] <obamoose> thank you
[20:44:10 CET] <obamoose> furq: okay I'm super confused
[20:44:49 CET] <obamoose> furq: I want to loop a folder
[20:45:08 CET] <obamoose> play all files -> play all files -> play all files -> play all files etc.
[22:57:14 CET] <AnonBaiter> is there any way I can compile ffmpeg on windows xp?
[22:57:43 CET] <__jack__> winxp ? common man, be serious
[22:58:47 CET] <AnonBaiter> windows xp
[22:59:02 CET] <AnonBaiter> i still use it through virtualbox
[22:59:18 CET] <AnonBaiter> or are you going to adapt to anti-comsumer tactics?
[23:02:29 CET] <AnonBaiter> I`m not in the mood to use windows 10 just to decode a file, you know
[23:02:56 CET] <AnonBaiter> but at least I have debian wheezy now
[23:19:40 CET] <Kadigan> AnonBaiter: there are ready-made binaries for Windows, but I don't think Windows XP is supported.
[23:19:59 CET] <Kadigan> I mean, come on - I was unable to compile ffmpeg on Windows 7. What makes you think you'll have more luck on XP?
[23:20:28 CET] <Kadigan> (granted, my inability to compile it on Windows was probably heavily influenced by my general ineptitude compiling linux-stuff on Windows...)
[23:31:23 CET] <furq> the zeranoe builds don't support xp because of libmfx
[23:31:31 CET] <furq> i'm not aware of anything else that'll prevent it from working
[23:32:47 CET] <AnonBaiter> so you`re saying it`s not possible to compile ffmpeg on windows xp?
[23:33:19 CET] <BtbN> Not caring about an ancient OS is not Anti-Consumer. It's just self-protection.
[23:33:46 CET] <BtbN> It might work, but nobody tests it or will fix bugs if there are any.
[23:34:39 CET] <rob0> I didn't see anyone say it wasn't possible to compile on XP.
[23:35:21 CET] <rob0> It's just that no one else cares.
[23:38:20 CET] <AnonBaiter> oops
[23:39:08 CET] <Fenrirthviti> windows xp support was dropped back in 2014, there are 0 legitimate reasons left to still be using it. And no, ancient software that only works there isn't a legitimate reason.
[23:40:12 CET] <AnonBaiter> so I have to use anything that`s not ancient regardless of how well they have aged?
[23:40:26 CET] <AnonBaiter> or how badly they have aged, I must say...
[23:40:30 CET] <Fenrirthviti> ...what? XP has not aged well at ALL.
[23:40:39 CET] <Fenrirthviti> XP was terrible when it was still current.
[23:40:53 CET] <AnonBaiter> even with the games you could play on it?
[23:41:17 CET] <Fenrirthviti> There is not a single game you can run on XP that doesn't work on modern OS's with minor tweaking. None.
[23:41:29 CET] <rob0> Entitlement
[23:41:40 CET] <AnonBaiter> I mean games released during the XP era
[23:42:00 CET] <Fenrirthviti> What does that have to do with anything?
[23:42:35 CET] <__jack__> maybe AnonBaiter want to use ffmpeg to record an old game ?
[23:42:39 CET] <AnonBaiter> well...
[23:42:43 CET] <AnonBaiter> at least i have linux
[23:42:51 CET] <AnonBaiter> but i have trouble installing ffmpeg on linux
[23:43:02 CET] <__jack__> AnonBaiter: which linux ?
[23:43:08 CET] <__jack__> which distribution
[23:43:08 CET] <AnonBaiter> debian wheezy
[23:43:11 CET] <AnonBaiter> wait
[23:43:32 CET] <AnonBaiter> https://tracker.debian.org/pkg/ffmpeg
[23:43:36 CET] <AnonBaiter> yeah that`s the one
[23:44:18 CET] <Fenrirthviti> what issues are you having? compiles fine on my wheezy box
[23:44:25 CET] <furq> wtf are you using wheezy for
[23:44:36 CET] <furq> do you have some policy of only using abandoned operating systems
[23:44:38 CET] <BtbN> well, at least it still has a tiny bit of support...
[23:44:45 CET] <BtbN> Wheezy is still in LTS
[23:45:18 CET] <Fenrirthviti> my wheezy box runs my arcade machine so I have no reason to update it :P
[23:45:40 CET] <AnonBaiter> mine is a amd64
[23:45:49 CET] <furq> he said "at least i have wheezy now" so i assumed he had just installed it
[23:45:55 CET] <furq> in which case, what the fuck are you doing
[23:46:16 CET] <__jack__> what the furq are you doing, AnonBaiter ?
[23:46:18 CET] Action: __jack__ runs
[23:46:32 CET] Action: rob0 was thinking the same thing :)
[23:46:33 CET] <AnonBaiter> trying to find a way to run ffmpeg on debian wheezy?
[23:46:42 CET] <AnonBaiter> I changed my plans
[23:47:02 CET] <BtbN> from running super ancient software to very ancient one?
[23:47:22 CET] <rob0> __jack__, our minds are seriously furqed up.
[23:47:36 CET] <__jack__> rob0: :3
[23:47:48 CET] <Fenrirthviti> ffmpeg should be available as a package in security on wheezy
[23:47:53 CET] <furq> jessie at least has ffmpeg in backports
[23:48:12 CET] <furq> stable distros are dumb though
[00:00:00 CET] --- Sat Mar 18 2017


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