[Ffmpeg-devel-irc] ffmpeg.log.20170907

burek burek021 at gmail.com
Fri Sep 8 03:05:01 EEST 2017

[01:43:09 CEST] <cryptodechange> Still having no luck with detelecine :(, either leaving interlaced like results or elements in motion have some merged blotching
[01:43:19 CEST] <cryptodechange> https://pastebin.com/hUqiC5Pg
[01:44:42 CEST] <cryptodechange> not sure if it's against the rules, but happy to drop $20 of BTC to whoever helps me solve it
[01:59:24 CEST] <cryptodechange> it seems the 2 interlaced frames are actually in motion, doing pullup,fps=24000/1001 causes interlaced artifacts... doing fieldmatch,yadif,decimate causes some motion judder in the moving elements
[03:10:25 CEST] <kepstin> cryptodechange: it's really hard to say without knowing what your source is like, but it sounds like you have blended fields
[03:10:41 CEST] <kepstin> might have been a framerate conversion from pal to ntsc?
[05:06:11 CEST] <alexpigment> hey guys: I don't know the ins and outs of AC3 audio, but is there a metadata option for the volume?
[05:06:36 CEST] <dystopia_> i don't believe so
[05:06:37 CEST] <alexpigment> I notice that sometimes when I preserve the original 5.1 ac3 stream and move to a new container, the volume drops considerably
[05:06:52 CEST] <dystopia_> what container?
[05:06:54 CEST] <alexpigment> I think that AC3 inherently has some sort of normalization parameter
[05:06:55 CEST] <alexpigment> MKV
[05:07:07 CEST] <dystopia_> i do that but don't notice a diffrence
[05:07:28 CEST] <alexpigment> I'm going from TS to MKV via Handbrake fwiw
[05:07:48 CEST] <dystopia_> hmm just tested an encode against my ts
[05:07:52 CEST] <dystopia_> the volume sounds the same
[05:08:47 CEST] <alexpigment> maybe it's just the way WMP plays it
[05:08:55 CEST] <alexpigment> perhaps it's ignoring the dialog normalization parameter
[05:10:18 CEST] <dystopia_> i do ffmpeg -i %input% -vn -sn -acodec copy %output%.ac3
[05:10:22 CEST] <dystopia_> after encoding the video
[05:10:26 CEST] <alexpigment> i always avoid VLC because it has really dumb scaling artifacts and doesn't deinterlace properly
[05:10:30 CEST] <dystopia_> then use mkvmerge to mux video and audio
[05:10:37 CEST] <alexpigment> what is -wn again?
[05:10:37 CEST] <dystopia_> i use mpc for playback
[05:10:45 CEST] <alexpigment> er
[05:10:49 CEST] <alexpigment> -sn i mean
[05:11:04 CEST] <dystopia_> -sn strips any subtitles
[05:11:07 CEST] <alexpigment> gotcha
[05:11:27 CEST] <dystopia_> which is kinda pointless for .ac3 but force of habbit
[05:11:32 CEST] <alexpigment> what benefits do you see from using mkvmerge vs ffmpeg?
[05:11:43 CEST] <dystopia_> in your .ts you will probably have dvbsubs and teletext subs
[05:11:53 CEST] <dystopia_> again just habbit
[05:12:08 CEST] <dystopia_> it's the way i scripted it, to use mkvmerge long ago
[05:12:10 CEST] <alexpigment> nah, i always record things from my dvr via a capture device, so no subs or teletext
[05:12:20 CEST] <alexpigment> gotcha
[05:12:26 CEST] <dystopia_> oh
[05:12:28 CEST] <dystopia_> ahdtv
[05:12:42 CEST] <alexpigment> yeah. everything on my cable is encrypted
[05:12:46 CEST] <alexpigment> no way to get it without capture
[05:12:52 CEST] <dystopia_> are you .uk?
[05:12:53 CEST] <alexpigment> but I can capture with the original ac3 audio
[05:13:02 CEST] <alexpigment> nope, 'murica
[05:13:06 CEST] <dystopia_> ahh
[05:13:20 CEST] <dystopia_> well in america you can use cablecard and hdhomerun iirc
[05:13:36 CEST] <alexpigment> the channels are encrypted though
[05:13:43 CEST] <alexpigment> no way to reverse that to my knowledge
[05:13:55 CEST] <dystopia_> your cablecard handls the decryption
[05:14:01 CEST] <dystopia_> cam module
[05:14:02 CEST] <alexpigment> are you sure?
[05:14:04 CEST] <dystopia_> yes
[05:14:10 CEST] <alexpigment> what is the cam module?
[05:14:12 CEST] <dystopia_> 100% certain
[05:14:14 CEST] <alexpigment> does it just capture the screen?
[05:14:15 CEST] <dystopia_> the cable card
[05:14:26 CEST] <dystopia_> no, it lets you access the raw transport stream
[05:15:21 CEST] <alexpigment> I mean I've researched this quite a bit, and all signs point to the contrary
[05:15:25 CEST] <dystopia_> in europe it's much more difficult as you can't just insert your card into a third party reciever or capture device
[05:15:32 CEST] <alexpigment> the CCI flag is still a thing
[05:15:36 CEST] <dystopia_> you have to hack the stb and get the box pairing key
[05:15:44 CEST] <dystopia_> and then set up a local sharing network
[05:16:18 CEST] <alexpigment> well, if you have any info on this, pm me. I'd like to avoid the hassle of secondary recording if possible
[05:16:42 CEST] <alexpigment> most everything I watch on tv has no life after broadcast. no online streaming, no DVD/Blu-ray, no digital purchase options
[05:16:44 CEST] <dystopia_> https://www.silicondust.com/product/hdhomerun-prime/
[05:16:58 CEST] <dystopia_> "Access premium cable subscription channels using CableCARD""
[05:17:13 CEST] <dystopia_> https://en.wikipedia.org/wiki/Conditional-access_module
[05:17:28 CEST] <dystopia_> im about to sleep but just google, all the info is public
[05:18:31 CEST] <alexpigment> I'm not trying to get into anything illegal - just recording for myself as if VCRs still exist :)
[05:18:47 CEST] <alexpigment> Anyway, I'll look it up. I had just always assumed that cablecards passed on the CCI flag
[05:19:01 CEST] <alexpigment> which my ISP puts on EVERYTHING now, including OTA channels
[05:19:12 CEST] <dystopia_> it's legal
[05:19:30 CEST] <dystopia_> in america they let you use your cable card in third party devices for decryption
[05:19:31 CEST] <alexpigment> no, i meant joining a scene release group :)
[05:20:02 CEST] <dystopia_> in europe it's also legal but you have to hack your device to do it and goes against terms of service with cable/satellite providers
[05:20:55 CEST] <alexpigment> https://forums.plex.tv/discussion/267947/hdhomerun-prime-time-warner-spectrum
[05:23:42 CEST] <dystopia_> you wouldnt use plex
[05:23:49 CEST] <dystopia_> you would use a proper application
[05:23:54 CEST] <alexpigment> so i can use WMC
[05:23:59 CEST] <dystopia_> like dvbviewer or npvr
[05:24:05 CEST] <alexpigment> or NPVR
[05:24:05 CEST] <dystopia_> yes you can use windows media center
[05:24:10 CEST] <alexpigment> but doesn't it pass on the CCI?
[05:24:14 CEST] <dystopia_> but your better off with a propwe app
[05:24:20 CEST] <dystopia_> cci?
[05:24:42 CEST] <alexpigment> CCI flag is what says the stream can be "copied freely", "copied once" or "copied never"
[05:25:00 CEST] <dystopia_> thats not in the transport streams
[05:25:07 CEST] <alexpigment> "copied freely" = this is good. but Spectrum / Time Warner doesn't have any channels that are copy freely anymore
[05:25:08 CEST] <dystopia_> that is set at your dvr/stb level
[05:25:23 CEST] <dystopia_> if you have access to the transport stream you can record whatever
[05:25:37 CEST] <alexpigment> Ok, I'll look into this again
[05:25:53 CEST] <alexpigment> I mean I trust your own experience. I just read a lot about this online before my current setup
[05:30:00 CEST] <dystopia_> http://i.imgur.com/jHQLnCe.jpg
[05:30:05 CEST] <dystopia_> decryption is fun :)
[05:31:13 CEST] <alexpigment> It doesn't sound like you live in America, and I'm doubting you've dealt with the DRM/CCI stuff
[05:31:25 CEST] <alexpigment> it's not just a matter of decrypting, really
[05:31:38 CEST] <dystopia_> i have friends in america that use hdhomerun and cablecards
[05:31:45 CEST] <alexpigment> Under what ISP?
[05:31:54 CEST] <alexpigment> ISPs here are monopolies
[05:32:19 CEST] <alexpigment> If your ISP isn't a major player, they probably don't have DRM on all of the channels
[05:32:30 CEST] <alexpigment> Spectrum / Time Warner has it on *all* channels
[05:32:48 CEST] <alexpigment> Meanwhile, I have friends who live 10 miles away who don't deal with the same thing on their ISP
[05:33:08 CEST] <alexpigment> They can get the streams directly from their DVR via firewire, actually
[05:34:10 CEST] <dystopia_> i sent him a message but he is afk atm it seems
[05:34:18 CEST] <dystopia_> but i will let you know when he replies
[05:34:40 CEST] <dystopia_> here anything thats recorded via dvr is locked to the box
[05:34:50 CEST] <dystopia_> so i gues thats the cci stuff your on about
[05:34:52 CEST] <alexpigment> Where are you?
[05:34:55 CEST] <dystopia_> .uk
[05:35:05 CEST] <alexpigment> UK apparently is pretty easy to get the raw streams from
[05:35:14 CEST] <alexpigment> A lot of TV rips come from there
[05:35:26 CEST] <dystopia_> but if you just hook your cable or sat feed up to a linux reciever like an enigma2 box, or a pc you can just get the transport stream directly
[05:35:27 CEST] <alexpigment> Via satellite at least
[05:37:01 CEST] <alexpigment> I mean I'm still reading. Everything I'm reading confirms what I'm saying
[05:37:19 CEST] <alexpigment> Spectrum (in my area at least), puts the DRM/CCI on everything
[05:37:40 CEST] <alexpigment> You can't use anything that isn't sanctioned, which limits you to WMC or a few other devices
[05:37:46 CEST] <dystopia_> the link you posted says you just need a cable card
[05:37:55 CEST] <alexpigment> But there is no way to do anything with those streams outside of watching it on the apps
[05:38:05 CEST] <alexpigment> http://www.dslreports.com/forum/r31203271-CATV-HDHomeRun-Prime-cable-card-Samsung-TV-DRM
[05:41:06 CEST] <alexpigment> to be clear, this is the relevant post: http://www.dslreports.com/forum/r31203610-
[05:42:46 CEST] <dystopia_> i read the whole thred :|
[05:43:01 CEST] <alexpigment> then you will see that copy freely channels can pass on without drm
[05:43:16 CEST] <alexpigment> copy-once channels must pass on the DRM via playready
[05:43:25 CEST] <dystopia_> i will ask my friend when he is around
[05:43:29 CEST] <alexpigment> all Spectrum channels in my area are either copy-once or copy-never
[05:43:29 CEST] <dystopia_> how he is doing it
[05:43:54 CEST] <dystopia_> you could just hack the box and set up a local card share server
[05:44:01 CEST] <alexpigment> well, your friend is in a different market, and probably with a smaller ISP that doesn't set CCI on anything but On Demand and premium channels
[05:44:17 CEST] <dystopia_> nah cuz he caps premium channels
[05:44:22 CEST] <alexpigment> the channels MUST be marked at copy-freely
[05:44:37 CEST] <alexpigment> well, his ISP must be pretty relaxed
[05:44:44 CEST] <alexpigment> (i.e. not a major company)
[05:44:56 CEST] <alexpigment> OR
[05:45:04 CEST] <alexpigment> he caps via capture on premium channels
[05:45:37 CEST] <alexpigment> anyway, let me know later I guess :)
[05:45:57 CEST] <dystopia_> nah cuz that would be ahdtv
[05:46:05 CEST] <dystopia_> and no one does that
[05:46:14 CEST] <alexpigment> ahdtv?
[05:46:18 CEST] <alexpigment> does the a mean analog?
[05:46:25 CEST] <dystopia_> analog hdtv
[05:46:26 CEST] <dystopia_> yes
[05:46:37 CEST] <alexpigment> well, does that encompass hdmi capture?
[05:46:45 CEST] <alexpigment> because it's all digital technically
[05:46:50 CEST] <alexpigment> it doesn't go out to component
[05:47:24 CEST] <alexpigment> (and yes, lots of people do that in the US :))
[05:48:09 CEST] <alexpigment> you can strip HDCP from HDMI, btw
[05:48:12 CEST] <alexpigment> that's easy
[05:48:20 CEST] <dystopia_> yes with a splitter
[05:48:21 CEST] <alexpigment> and that's how most capture works
[05:48:25 CEST] <dystopia_> but that is analogue and sucky
[05:48:47 CEST] <alexpigment> again, "analog" seems like a weird description there, but I get your point
[05:48:58 CEST] <alexpigment> you have to basically re-encode raw HDMI frames
[10:11:32 CEST] <mozzarella> guys
[11:27:55 CEST] <Commander_Cody> I'd like to record only a specific window.
[11:29:07 CEST] <Commander_Cody> Tried the options '-f gdigrab -i title="Warzone 2100"' instead of the usual '-f x11grab -i $DISPLAY' and FFmpeg exited with a warning 'Unknown input format: 'gdigrab'.
[11:29:29 CEST] <Commander_Cody> I use ArchLinux with the i3 tiling window manager in case that matters.
[11:40:48 CEST] <dystopia_> @ alexpigment he uses fios
[11:43:57 CEST] <furq> Commander_Cody: gdigrab is for windows
[11:46:50 CEST] <Commander_Cody> furq: I *do* know the coordinates of what I want to record.
[11:47:00 CEST] <Commander_Cody> Could I give those?
[11:47:12 CEST] <furq> with x11grab, sure
[11:47:48 CEST] <Commander_Cody> furq: Mind telling me how ? :)
[11:48:27 CEST] <furq> !indev x11grab @Commander_Cody
[11:48:28 CEST] <nfobot> Commander_Cody: http://ffmpeg.org/ffmpeg-devices.html#x11grab
[11:50:46 CEST] <blap> then there's the fun of setting up your alsa loopback for the record
[11:51:12 CEST] <fsphil> that really doesn't like my dual screen setup, with the screens not being the same size. some weird stuff going in in the null space :)
[11:52:35 CEST] <redrabbit> wait for 2018 the year of linux desktop
[11:52:44 CEST] Action: redrabbit has zero double screen issues on win10
[11:54:26 CEST] <Commander_Cody> Only noobs want a desktop :|
[11:54:35 CEST] <Commander_Cody> window managers are still a superior concept.
[11:55:16 CEST] <JonG> What is the best way to slow down an audio track without applying a pitch correction? The atempo filter seems to always apply a pitch correction. I would want that tempo 0.5 would slow down the audio, but also make e.g. voices deeper. I think if I pre-calculate the audio rate, apply asetrate with that value divided by 2, and then aresample back to
[11:55:16 CEST] <JonG> the original rate, I will get the desired effect, but requiring multiple stages.
[11:56:19 CEST] <furq> JonG: probably rubberband if your ffmpeg was built with it
[11:56:22 CEST] <fsphil> https://www.youtube.com/watch?v=vGICEQ5gspQ
[11:56:43 CEST] <furq> asetrate,aresample is the best way i know of without rubberband
[11:57:55 CEST] <fsphil> reminds me of a migraine
[11:58:41 CEST] <JonG> Ah OK thanks furq. I will try building with rubberband and see how that goes. https://ffmpeg.org/ffmpeg-filters.html#rubberband
[11:59:11 CEST] <fsphil> is there a way of using x11grab with just a url, without the -f argument?
[12:29:50 CEST] <nwoki_> hi all. I have a problem streaming images. What i do is use the following command: "ffmpeg -f image2 -loop 1 -i /tmp/image.jpg  -pix_fmt yuv420p -f flv rtmp://dev-cube6:1935/live/webcam" to stream an image. All goes well. But when i change the image by saving another one over it, the stream is not updated. Any clues why?
[12:46:27 CEST] <Nacht> nwoki_: ffmpeg loads all the inputs before hand, and then outputs them. Changing them won't make a difference, as it's already in its buffer
[12:46:50 CEST] <nwoki_> is there a way to tell ffmpeg to constantly clear its buffer?
[12:46:54 CEST] <nwoki_> Nacht:
[12:47:33 CEST] <BtbN> no
[12:47:59 CEST] <BtbN> use image2pipe and just keep piping the file into ffmpeg
[12:48:27 CEST] <nwoki_> was doing that but the stream to rtmp results to be quite slow
[12:48:53 CEST] <nwoki_> that's why I tried to change solution
[12:49:06 CEST] <nwoki_> by streaming the same file and constantly updating that file with new data
[12:49:30 CEST] <BtbN> what?
[14:20:24 CEST] <maxhap> Hi guys, I'm trying to build FFmpeg with libass using the MSVC compiler but have been unable to correctly link the libraries, I have added a detailed explanation to this shared document. https://1drv.ms/t/s!AlxIO9rf94uPtOEf9Q_Uw-MEQRlNog If anyone could be so kind as to give me some pointers where I might be going wrong I would be extremely greatfull
[14:30:22 CEST] <SudoSu> Hi, by some reasons my FFMPEG stucks at start. I'm trying to get an UDP MPEG2 stream, I see the network load on my VLAN interface but the transcoding of the input stream (with HLS) is not starting. I'm using Ubuntu 16.04 server and the most recent FFMPEG build with NVIDIA Cuda support. With CPU transcoding on my other server it's working fine (Debian). I can't switch to newer Ubuntu/Debian because NVIDIA not
[14:30:24 CEST] <SudoSu> supports newer versions. If I can't see the answer here, could you mail me please? husudosu94[at]gmail.com. Thanks!
[14:31:55 CEST] <stevenliu> SudoSu: Hello?
[14:32:43 CEST] <stevenliu> Can you record a mpegts file to me?  ffmpeg -i input -c copy -t 60 output.ts
[14:32:52 CEST] <stevenliu> and send the output.ts to me
[14:33:48 CEST] <SudoSu> I'm here
[14:34:09 CEST] <SudoSu> I try it from my other server it's okay for you?
[14:34:58 CEST] <SudoSu> Or I can provide a FFPROBE too, if it's better for you.
[14:36:03 CEST] <stevenliu> No, Just mpegts file to me
[14:36:21 CEST] <stevenliu> ffmpeg -i input -c copy -t 60 output.ts  or let me login your server try the nvenc
[14:40:22 CEST] <SudoSu> TS file: https://1drv.ms/u/s!AlIDARy55xh43zz-Sbcd3lGeZR2o
[14:43:22 CEST] <SudoSu> There's no problem with the NVIDIA Encoder if I'm trying local file. But when I try to get an UDP stream, FFMPEG got stuck, there's no error message.
[14:43:44 CEST] <SudoSu> But with my other server it works just fine
[14:48:45 CEST] <stevenliu> Is this record by the nvenc server?
[14:49:51 CEST] <SudoSu> Nope, but I'll explain the whole problem in E-mail okay?
[14:50:00 CEST] <stevenliu> ok
[14:56:42 CEST] <mozzarella> guys
[15:04:36 CEST] <durandal_1707> lads
[15:06:56 CEST] <mozzarella> how can I limit the cpu usage of ffmpeg
[15:07:12 CEST] <mozzarella> I want to convert some file but I don't want the fan to make too much noise
[15:07:18 CEST] <durandal_1707> you dont
[15:07:24 CEST] <durandal_1707> reduce threads
[15:07:34 CEST] <mozzarella> even with one thread it's too much
[15:10:39 CEST] <durandal_1707> are you using filters?
[15:12:27 CEST] <mozzarella> what's that
[15:13:53 CEST] <durandal_1707> mozzarella: processing video and audio effects
[15:14:44 CEST] <mozzarella> no
[16:06:08 CEST] <alexpigment> @dystopia_ that's kinda what I figured. Fios has their CCI flag set to "copy freely" for almost everything, according to what I'm seeing online
[16:18:40 CEST] <mozzarella> durandal_1707: no
[16:18:58 CEST] <mozzarella> you went quiet on me
[16:19:56 CEST] <durandal_1707> mozzarella: are you on linux?
[16:28:29 CEST] <spalpeen> i am interested in modifying the decoding section of ffmpeg to only decode a certain region
[16:28:54 CEST] <JEEB> not possible in decoder
[16:28:57 CEST] <spalpeen> is this possible? I find multiple references to decode_mb  which looks like the multiblock decoding.
[16:29:06 CEST] <JEEB> as in, most formats do not let you do those blocks separately
[16:29:13 CEST] <spalpeen> i am searching for a loop over multiblocks but so far do not find
[16:29:47 CEST] <spalpeen> the loop over multiblocks to produce image would be inside the codec then?
[16:30:02 CEST] <spalpeen> for instance if i am intstd in h264 i need to  mod that codec?
[16:31:14 CEST] <BtbN> you can't do that
[16:31:21 CEST] <BtbN> That's not how video codecs work.
[16:31:56 CEST] <BtbN> The frames two frames after the one you just decoded uses one of the outside blocks as reference. You didn't decode it, so can't use it.
[16:34:29 CEST] <spalpeen> i am willing to allow errors creep into edges of the region
[16:35:14 CEST] <spalpeen> so i would ignore the motion corrections coming from neighbor blocks outside of the region of interest
[16:35:24 CEST] <BtbN> It would entirely wreck the entire decode
[16:35:30 CEST] <BtbN> It's not possible
[16:35:53 CEST] <mozzarella> durandal_170: yes
[16:36:00 CEST] <BtbN> Might be for some more simple codec, but definitely not for h264
[16:39:33 CEST] <spalpeen> i dont see a h264 decoder section at https://www.ffmpeg.org/ffmpeg-codecs.html, only the encoder?
[16:41:47 CEST] <spalpeen> under libavcodec I find h264_direct.c , also around 20 other files with h264 in the name
[16:43:13 CEST] <BtbN> the Video Decoders section looks broken.
[16:44:53 CEST] <spalpeen> can you give a heads up where e.g. a loop over macroblocks in the decoder would be ? there's quite a few h264 .c and .h files
[16:45:13 CEST] <BtbN> You are thinking of this way too simple.
[16:45:26 CEST] <BtbN> Multiple people have told you that it's not going to work.
[16:46:59 CEST] <spalpeen> i'm curious to try and see the reproduction error
[16:52:26 CEST] <spalpeen_> .
[17:14:35 CEST] <pupek> Hi everyone, i have a question regarding decoding of h264.
[17:14:51 CEST] <pupek> My h.264 stream is encapsulated inside MPEG-2 TS stream.
[17:16:04 CEST] <pupek> What i desire to do: looking at a payload of MPEG-2 TS packet i want to tell if there is an ending of h.264 frame inside. How i'm doing it now: i search for the beginning of next h.264 frame in next ts packets. When i find it, i know, that previous ts packet of the same pid must contain the end of the h.264 frame.
[17:17:03 CEST] <pupek> I heard there is a function in ffmpeg that does just this - searches endings of frames, do you guys know what it could be or where to find it?
[17:31:17 CEST] <BtbN> it could also just be filler data
[17:37:25 CEST] <pupek> you mean in previous ts packet? It would contain filler data to make it 188 bytes long and the ending of the frame. There are no ts packets that consist entirely of filler data in my stream afaik
[17:44:49 CEST] <fsphil> packets with PID 8191 are entirely padding
[17:50:45 CEST] <pupek> i operate in the limits of one known video PID
[17:51:12 CEST] <pupek> that is certain to contain h264 stream
[17:51:27 CEST] <rmk0> 'lo. i'm using ffmpeg to produce a video from a sequence of PNG images produced by Blender. this works well (see: http://ataxia.io7m.com/2017/09/06/chemriver_night_20170906_0000.mkv) but i'd like to add a title card that lingers for ~5 seconds before the video starts playing, and i'd like to fade the video to black over the final second or so. is it possible to do this from the command line?
[17:51:42 CEST] <rmk0> i could edit the video in kdenlive or whatever, but that'd (i believe) involve a lossy re-encoding
[17:51:59 CEST] <pupek> and in ts packets of that pid there is a need to find the endings of h.264 frames
[18:09:13 CEST] <pihpah> Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 517 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
[18:09:22 CEST] <pihpah> 517 kb/s is that bits or bytes ?
[18:10:30 CEST] <jkqxz> Bits.
[18:11:45 CEST] <pihpah> jkqxz: that not much, thought it would have been much greater for 720p videos.
[18:12:06 CEST] <jkqxz> Depends how you encode it and what the content is.
[18:15:53 CEST] <BtbN> And that value there is just a pure guess
[18:19:27 CEST] <pihpah> I am justing wondering how many users I would be able to serve per day, I mean serving 720p videos, having 100 Mbit/s bandwidth so that they won't experience any lags or video stuttering.
[18:19:58 CEST] <pihpah> I am just*
[18:23:54 CEST] <BtbN> depends entirely on the bitrate you encode them with
[18:39:03 CEST] <voip_> Hello guys, as i know GPU's like Nvidia GTX1060 has limitation up 2 live streams with transcoding.
[18:39:03 CEST] <voip_> Is it possible unlock and run ore streams ?
[18:40:49 CEST] <BtbN> That's called buying a Quadro Card
[18:42:16 CEST] <voip_> I have 1060, so is it possible ?
[18:43:05 CEST] <jkqxz> Quadro P2000 is the same chip without that limit.  (Slightly different stats, but the same hardware.)
[18:43:05 CEST] <BtbN> no
[18:43:15 CEST] <voip_> :(
[18:44:00 CEST] <voip_> so limitation comes from drivers ?
[18:44:22 CEST] <BtbN> Or it's burned into the silicion, who knows.
[18:44:44 CEST] <Fenrirthviti> Likely the drivers, but good luck trying to break in there.
[18:45:11 CEST] <voip_> :)
[18:45:58 CEST] <furq> i'd have thought it'd be in firmware
[18:46:04 CEST] <furq> but yeah, good luck with that
[18:49:21 CEST] <DHE> I suspect it's the drivers. as I understand it mixing and matching the cards will cause the 2 stream limit to suddenly show up and affect the quadro
[18:49:43 CEST] <furq> oh really
[18:49:44 CEST] <Fenrirthviti> yeah, I've heard that too.
[18:50:06 CEST] <Fenrirthviti> having a non-quadro card in the system at all basically cripples everything that makes quadro cards worth it
[18:50:15 CEST] <furq> it's amazing how quickly i stopped being surprised by how stupid that is
[18:50:26 CEST] <Fenrirthviti> well "worth it" meaning more "the extra things quadros can do"
[18:51:44 CEST] <Fenrirthviti> My fav stupid thing they do is that if any card on the system has CUDA active, it just kills everything else trying to use CUDA, even on a different GPU.
[18:51:56 CEST] <Fenrirthviti> Have Premiere open? Sorry, you can't use nvenc.
[18:52:44 CEST] <Fenrirthviti> Recent change, too. Running into people who do video editing tutorials and all of a sudden can't record
[18:53:16 CEST] <Fenrirthviti> With the very awesome and helpful "out of memory" error
[18:54:49 CEST] <BtbN> that sounds more like a bug
[18:55:06 CEST] <BtbN> They probably never test the Quadros on the normal drivers
[19:25:45 CEST] <doublya> Building ffmpeg with cuda. /usr/bin/ld: cannot find -lGL
[20:00:12 CEST] <saml_> is ffmpeg scale?
[20:53:20 CEST] <DHE> saml_: what do you mean?
[20:56:48 CEST] <saml_> DHE, no idea. it looks like a good program
[21:46:42 CEST] <technick> Anybody have a cheat sheet for re-encoding media to save space?
[21:50:31 CEST] <vlt> technick: Usually not worth it.
[21:50:58 CEST] <vlt> technick: What media do you have currently?
[21:52:22 CEST] <technick> A bunch of concert bootlegs, averaging 10+ gigs for one hour of footage.
[21:52:45 CEST] <technick> and high quality bootlegs, sound is coming off mixer
[21:54:18 CEST] <vlt> technick: In 10GB/h? In DNxHD or something like that?
[21:54:47 CEST] <technick> MTS files
[21:56:52 CEST] <vlt> technick: You could try libx264 codec for video with a quite low value for "-crf".
[21:57:20 CEST] <vlt> Or x265 (but I personally have never tried that before).
[21:57:31 CEST] <kepstin> 10gb/h is about 24mbit/s which is a bit high, yeah
[21:57:33 CEST] <durandal_1707> technick: encode to gif
[21:57:50 CEST] <furq> he said he wanted to make it smaller
[21:58:22 CEST] <technick> lol
[21:58:49 CEST] <durandal_1707> than encode it to xface
[21:58:54 CEST] <technick> I'm doing a test encode now using libx264 with a crf of 18
[21:59:03 CEST] <kepstin> technick: but yeah, it basically comes down to "re-encode with x264 in crf mode with a slow preset"
[21:59:03 CEST] <furq> 18 is pretty high
[21:59:17 CEST] <kepstin> and if the audio is pcm or something, compress that.
[22:00:22 CEST] <technick> Do I need to demux the audio first?
[22:00:56 CEST] <vlt> technick: No.
[22:01:10 CEST] <iive> furq: you mean low.
[22:01:19 CEST] <furq> i mean both
[22:01:39 CEST] <vlt> technick: ffmpeg -i srcfile -preset veryslow -crf 18 -codec:a copy -t 300 out.mkv
[22:02:00 CEST] <vlt> technick: This will encode the first 5 minutes. (-t 300)
[22:02:54 CEST] <technick> I'll give it a whirl, thanks for the info
[22:34:30 CEST] <przemoc> hi, is there anyone who could help me answering the question why video sped up (25fps -> 50fps) with ffmpeg (ffmpeg -i a.mp4 -c copy -f h264 a.h264; ffmpeg -r 50 -i a.h264 -c copy b.mp4) is jerky in chrome browser?  (it plays fine in ffplay, mpv or MPC)
[22:36:05 CEST] <JEEB> raw H.264 muxing into certain containers can go wrong
[22:36:11 CEST] <JEEB> try L-SMASH's muxer
[22:36:19 CEST] <JEEB> https://github.com/l-smash/l-smash
[22:37:10 CEST] <przemoc> oh, I used to use it ages ago.  are there windows binaries?
[22:37:19 CEST] <przemoc> you provided them in the past IIRC
[22:37:47 CEST] <cryptodechange> What's the best way to help color loss when using nlmeans?
[22:37:59 CEST] <JEEB> which would be `muxer -i "a.h264?fps=50" -o out.mp4 (and maybe with --optimize-pd)
[22:38:16 CEST] <przemoc> or maybe it was ffmpeg with l-smash patches, too long ago to remember
[22:38:26 CEST] <JEEB> no l-smash patches for FFmpeg :)
[22:38:52 CEST] <durandal_1707> cryptodechange: what kind of color loss?
[22:40:42 CEST] <przemoc> JEEB: sorry, you provided something on your site long time ago, some patched ffmpeg, don't remember details
[22:42:11 CEST] <cryptodechange> durandal_1707: https://i.imgur.com/8sdbRfG.png
[22:42:32 CEST] <cryptodechange> left has nlmeans=s=2:p=3:rc=1
[22:44:02 CEST] <przemoc> cannot find L-SMASH for windows, so it seems I have to build it myself on Linux
[22:45:07 CEST] <JEEB> it really has little in the way of deps so should be simple enough. even on windows just grab the mingw-w64 toolchain on msys2 and it should Just Work
[22:45:14 CEST] <cryptodechange> a 480p DVD convert produces only 80% of the original filesize using CRF=15
[22:45:21 CEST] <cryptodechange> Without any denoising
[22:46:00 CEST] <przemoc> JEEB: oh, haven't checked deps yet, thanks.  I have up-to-date msys2 on my laptop.
[22:46:06 CEST] <przemoc> will try
[22:46:42 CEST] <furq> i have windows git builds here if you want them
[22:47:50 CEST] <przemoc> I'd be glad to take them.  it will save me a few minutes, I guess.
[22:48:02 CEST] <furq> http://b23.be/lsmash/lsmash_20170305_a660f91_x86_64.tar.xz
[22:48:24 CEST] <przemoc> thanks!
[22:51:29 CEST] <przemoc> BTW it indeed built flawlessly on MSYS2 on up-to-date MinGW-w64
[22:57:50 CEST] <przemoc> yeah, no jerkiness
[22:58:07 CEST] <przemoc> JEEB: thanks!
[22:58:36 CEST] <przemoc> so it's still better to not use ffmpeg for muxing mp4s?
[22:58:44 CEST] <przemoc> I mean: at all?
[22:59:24 CEST] <przemoc> BTW I didn't use --optimize-pd.
[23:04:41 CEST] <przemoc> maybe other question, if L-SMASH is better at muxing MP4, aren't there anyone versed in both ffmpeg and L-SMASH who would be able to improve ffmpeg's part responsible for handling that?
[23:05:13 CEST] <przemoc> or are there some fundamental architectural differences that make it impossible?
[23:05:26 CEST] <przemoc> s,impossible,very hard,
[23:06:20 CEST] <JEEB> it's IIRC more to do with using more information from the H.264 parsing and having the user define a frame rate
[23:06:35 CEST] <JEEB> -39
[23:07:28 CEST] <przemoc> ENOTEMPTY?
[23:13:31 CEST] <cryptodechange> How does ffmpeg/x264 calculate the maximum number of reference frames?
[23:14:51 CEST] <furq> preset or level
[23:15:12 CEST] <furq> or -refs, but hopefully that one is obvious
[23:22:31 CEST] <cryptodechange> do grainy/old sources generally need a much higher CRF than non-grainy/clean?
[23:22:52 CEST] <cryptodechange> The bitrate difference is quite large
[23:23:36 CEST] <przemoc> AFAIK if you want to preserve grain, then you do need higher CRF, therefore you get higher bitrate.
[23:23:53 CEST] <kepstin> if you encode a video with more detail at the same crf & other settings as one with less detail, there will be a large bitrate difference, yes
[23:24:28 CEST] <cryptodechange> But the perceived quality difference between typical crf differences
[23:25:09 CEST] <cryptodechange> e.g. some people can notice some degradation between a 18 CRF and 22 CRF using the same settings
[23:25:21 CEST] <cryptodechange> but to get an acceptable bitrate, I will need to use 22 CRF, or even higher
[23:25:40 CEST] <kepstin> crf acts as a quality-based encoding setting, yes
[23:25:48 CEST] <kepstin> lower crf = higher quality, therefore more bits
[23:25:57 CEST] <kepstin> (assuming same video source)
[23:26:36 CEST] <cryptodechange> I suppose for the purpose of plex media transcoding, a dragged out encode will always be better than live, no matter the crf
[23:26:39 CEST] <przemoc> oops, I menat s/higher CRF/lower CRF/ of course
[23:26:46 CEST] <przemoc> s/menat/meant/
[23:26:47 CEST] <kepstin> if you need a specific bitrate, then do a 2-pass encode.
[23:27:22 CEST] <cryptodechange> For consistent grain, I wonder what the difference would be for a high crf or a 2pass with similar bitrates
[23:27:25 CEST] <kepstin> a single-pass encode done in crf mode should be almost exactly the same quality as a 2-pass encode which ends up at the same size
[23:27:27 CEST] <cryptodechange> end result bitrates*
[23:28:24 CEST] <cryptodechange> So just up the CRF when testing encode segments until I'm happy with the overall bitrate
[23:29:18 CEST] <kepstin> well, if you do that, simple/less grainy stuff will undershoot your target bitrate and not look as good as it could
[23:29:54 CEST] <cryptodechange> but wouldn't i be in the same predicament with 2pass?
[23:30:10 CEST] <kepstin> normally you want either "everything should be min this quality -> use crf" or "everything should meet this bitrate/size spec -> use 2pass"
[23:30:28 CEST] <cryptodechange> I've tinkered with denoising filters, but I am noticing some colour juddering (e.g. flat or static backgrounds), general judder from frame shake and colour loss in darker/finer details
[23:32:27 CEST] <kepstin> "juddering" has a specific meaning in video encoding regarding frame timing, are you sure that's what you mean?
[23:32:54 CEST] <cryptodechange> No that's not it, the closest I can describe it is when you look through the fumes of a fire
[23:33:07 CEST] <cryptodechange> and it distorts the image, but a bit more subtle
[23:33:32 CEST] <kepstin> denoising filters will often cause some amount of smearing of details
[23:33:33 CEST] <cryptodechange> it's more noticeable in gradients
[23:34:25 CEST] <kepstin> you'd probably have to provide an image or video of what you're describing, I'm not sure I understand.
[23:35:15 CEST] <cryptodechange> For the detailed colours being smeared: https://i.imgur.com/8sdbRfG.png
[23:35:22 CEST] <cryptodechange> Let me grab a sample of the gradients
[23:43:38 CEST] <cryptodechange> what's the best way to share a sample video kepstin?
[23:44:47 CEST] <kepstin> hmm, I dunno, a couple of frames would probably be enough here? Don't put it on youtube or whatnot, they re-encode the video and it might either mask or exaggerate the effect
[23:46:38 CEST] <cryptodechange> Try this
[23:46:41 CEST] <cryptodechange> https://drive.google.com/file/d/0B6rDPzFC8IitdnUxUVVpb19qN2M/view?usp=sharing
[23:46:46 CEST] <cryptodechange> Will need to download the original file
[23:47:33 CEST] <blap> We are divided
[23:47:34 CEST] <blap> The enemy rules
[00:00:00 CEST] --- Fri Sep  8 2017

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