[Ffmpeg-devel-irc] ffmpeg.log.20141230

[burek]

[00:43] <Eryn_1983_FL> ok
[01:37] <ParkerR> Are there any setups where ffmpeg is accelerated? I'm planning a new machine and wasnt sure if there was anything in particular that would helo towards video encoding/decoding
[01:38] <ParkerR> *help
[01:44] <klaxa> you can do hardware decoding for a bunch of codecs with graphics cards
[01:45] <klaxa> for example vdpau can accelerate h264 decoding
[01:47] <ParkerR> klaxa: Well my current setup has VAAPI but that doesnt seem to be supported all that well
[01:47] <klaxa> https://trac.ffmpeg.org/wiki/HWAccelIntro
[01:47] <ParkerR> And none of it seems to be enabled by default/I dont see a way to enable
[01:47] <ParkerR> Yeah I saw that
[01:48] <klaxa> in the manpage there is explained how to use vdpau for hardware decoding, vaapi is not listed not sure if it can be supported
[01:48] <jarainf> On the other hand you could always go for raw CPU power
[01:51] <ParkerR> Yeah. Anything would be an upgrade over what I have. Two main machines. One Core 2 2.13ghz P7450 and Celeron Dual core 1.1ghz 847
[01:55] <klaxa> do your machines have intel graphic chips?
[01:56] <ParkerR> klaxa: The 847 is
[01:56] <ParkerR> ~HD2000
[01:56] <klaxa> i doubt you will be able to utilize that
[01:56] <ParkerR> Yeah thats why I was thinking about a nnice desktop
[01:56] <ParkerR> *nice
[03:10] <jswensen> I have been trying to solve some audio sync problems and cant figure the right command line options to prevent it. MP4s are created on iOS device. Converting to TS so I can split it for HTTP Live Streaming. Here is a simple example of the MP4->TS conversion that shows the audio sync getting progressively worse. http://pastebin.com/pfXqpwH2
[03:27] <jswensen> Even the simple command: ffmpeg -i 51305A0C-49E0-4695-BCF3-DCD1A9258FE4.mp4  51305A0C-49E0-4695-BCF3-DCD1A9258FE4_out.mp4 is causing the sudio sync  problem
[05:28] <squeegily> Hey guys. What was the command to discard everything but the second frame?
[05:28] <squeegily> I remember it had to do with "select"
[05:38] <squeegily> Aha it's ffmpeg -i /dev/video0 -vf select='eq(n\,2)' -vframes 1 test.jpg
[11:42] <edoardo> hello
[11:42] <edoardo> ffmpeg -f s16le -ar 48k -ac 1 -i pipe:0 -c:a libaacplus -b:a 32k test.m4a
[11:42] <edoardo> this works
[11:42] <edoardo> ffmpeg -f s16le -ar 48k -ac 1 -i pipe:0 -c:a libaacplus -b:a 32k pipe:1.m4a
[11:42] <edoardo> this doesn't work
[11:43] <edoardo> "Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
[11:43] <edoardo> "
[11:43] <edoardo> "[ipod @ 0x1c56680] muxer does not support non seekable output"
[11:56] <SirDarius> edoardo: alas, a pipe is not seekable, and your muxer needs a seekable output. this can happen if the muxer needs to update parts of the file, for example a header, after the file has been written already
[11:56] <edoardo> so how could i reencode a stream on the fly?
[11:56] <edoardo> the output gets transmitted via oggfwd
[11:59] <SirDarius> do you have to use M4A ? Someone correct me if I'm wrong but I'm not sure it is  streamable
[11:59] <Mavrik> edoardo, mux to something else.
[11:59] <edoardo> Mavrik: like? i don't know what's used for streaming
[11:59] <Mavrik> edoardo, like important question.
[11:59] <Mavrik> edoardo, why are you muxing audio to MP4 ... instead of OGG when you're using OGGFWD?
[12:00] <Mavrik> I'd also think that oggfwd expects OGG Vorbis audio, not AAC
[12:00] <edoardo> oggfwd just streams whatever you put in stdin
[12:00] <edoardo> it doesn't care of what you are streaming
[12:01] <Mavrik> I doubt it.
[12:01] <Mavrik> Especially if you're trying to stream a non-streamable format like MP4.
[12:04] <edoardo> Mavrik: it actually sends the stream, but the browser nor any player can play it
[12:08] <SirDarius> edoardo: you might want to try ADTS, if whatever you are streaming to supports it: ffmpeg -f s16le -ar 48k -ac 1 -i pipe:0 -c:a libaacplus -b:a 32k -f adts pipe:1.aac (-f adts is not necessary here, it is implied by a .aac extension)
[12:12] <edoardo> SirDarius: can't decode it :\
[12:14] <edoardo> Input #0, aac, from 'test.aac':
[12:14] <edoardo>   Duration: 00:00:29.27, bitrate: 48 kb/s
[12:14] <edoardo>     Stream #0:0: Audio: aac (HE-AACv2), 44100 Hz, stereo, fltp, 48 kb/s
[12:14] <edoardo> this is from a stream that works
[12:14] <SirDarius> or a TS, maybe ? ffmpeg -f s16le -ar 48k -ac 1 -i pipe:0 -c:a libaacplus -b:a 32k -f mpegts pipe:1.ts
[12:15] <edoardo> can't open
[12:15] <Mavrik> why don't you check what your streaming server actually supports first.
[12:15] <Mavrik> Then find out of you can deliver content directly wihtout oggfwd crap
[12:15] <Mavrik> Since you're obviously using the wrong tool for the job you're trying to do.
[12:16] <Mavrik> THEN start blindly copy-pasting commands.
[12:16] <edoardo> i actually switched to ezstream after you told me that oggfwd was the wrong tool :)
[12:16] <SirDarius> i don't like being on the Y side of XY, more details are needed, indeed
[12:16] <edoardo> blablabla | ezstream -c aac.xml
[12:17] <edoardo> so, i have a opus stream that i'd like to reencode to aac
[12:18] <edoardo> i'm currently using this: opusdec --quiet --rate 48000 - - | ffmpeg -f s16le -ar 48k -ac 1 -i pipe:0 -c:a libaacplus -b:a 32k -f mpegts pipe:1 | ezstream -c aac.xml
[12:18] <Mavrik> hmm
[12:18] <edoardo> fact is, it works when i reencode to vorbis/mp3
[12:18] <edoardo> but doesn't work with aac
[12:18] <Mavrik> yes, because of different containers
[12:18] <Mavrik> edoardo, first question, why aren't you using ffmpeg directly?
[12:19] <Mavrik> IIRC it supports opus
[12:19] <edoardo> Mavrik: because i have one opus stream that i want to reencode to multiple streams
[12:19] <Mavrik> also cutting out the piping will fix alot of your issues with containers
[12:19] <Mavrik> but yes, your issue is that m4a/mp4 is not a streamable container per se and requires a streaming server to put it together
[12:19] <edoardo> so i'm using wget | oggdec | tee (encoder1 | ezstream) (encoder2 | ezstream) (encoder3|ezstream)
[12:20] <Mavrik> hence you're better off delivering your audio to your streaming server in a streamable container
[12:20] <Mavrik> why are you using ezstream and not streaming to icecast with ffmpeg directly?
[12:21] <edoardo> Mavrik: the ffmpeg version i'm using for whatever reason doesn't want to stream to icecast
[12:21] <edoardo> ffmpeg version 2.5.1 Copyright (c) 2000-2014 the FFmpeg developers
[12:23] <SirDarius> is icecast listed in the output of "ffmpeg -protocols" ?
[12:24] <edoardo> yes
[12:26] <edoardo> hey! it works! but i get a very glitchy sound
[12:27] <edoardo> adts works perfectly! :)
[12:27] <edoardo> thank you!!
[15:00] <gaspard> how could I create a stream like http://ice38.infomaniak.ch:8000/radiomeuh-128.mp3 ?
[15:00] <c_14> use something like icecast or another streaming server?
[15:10] <Mavrik> yep
[15:10] <Mavrik> gaspard, by the domain name I presume they use icecast streaming server... ffmpeg can stream audio TO icecast :)
[15:22] <gaspard> okay, thnx Mavrik and c_14, that was a missing piece, now I can start looking more effectively :-)
[15:23] <gaspard> is there an easy way to stream with ffmpeg ? with ffserver ?
[15:23] <gaspard> (I should have only subscriber to the live audio )
[15:24] <c_14> you _can_ stream with ffserver. The ease thereof depends.
[15:34] <edoardo_> how can i install ffmpeg on wheezy?
[15:34] <edoardo_> i have avconv right now :\
[15:34] <c_14> Get a static build, compile from source, get ffmpeg from testing
[15:37] <BtbN> testing already has it? As in, the upcoming release?
[15:38] <edoardo_> BtbN: yes, testing has ffmpeg
[15:38] <edoardo_> wheezy has still ffmpeg version 0.8.16-6:0.8.16-1, Copyright (c) 2000-2014 the Libav developers
[15:52] <fmiz> Hi all! I'm a noob with ffmpeg, I'm trying to test if I can stream video from my webcam to youtube, but I'm stuck. I figured that youtube takes in input only audio+video streams. I'm not interested in streaming audio, so I'm trying to add an empty audio track to my video, but I don't understand what's happening
[15:55] <Trixboxer> Hello Everyone, Im trying to convert video into Black&Blue. I'm able to do it B&W but not able to find option to make it Black&Blue
[15:56] <fmiz> This is what I see: http://pastebin.com/7GQgN7AZ
[16:14] <Mavrik> gaspard, am
[16:14] <Mavrik> gaspard, if you have icecast, then it already replaces ffserver
[16:14] <Mavrik> so you just do ffmpeg -i <your file> -c copy icecast://<icecast-server> to stream to the icecast
[16:14] <gaspard> yes, I just installed a icecast server and configured it, now my radio is live
[16:15] <gaspard> sorry I didn't post anything, I got this working an hour ago
[16:16] <gaspard> the installation on ubuntu is really easy (apt-get and a few steps)
[16:16] <gaspard> pluging it to ffmpeg is nice too
[16:17] <gaspard> i will post a gist when I get some clean result
[16:17] <Mavrik> ok, good to hear that
[16:19] <c_14> fmiz: does that error occur only when you add the audio stream?
[16:19] <gaspard> I am doing this to voice chat to mobile phone browsers because it occurs that  <audio id="audio" src="http://ice38.infomaniak.ch:8000/radiomeuh-128.mp3" controls></audio> works well with iOS/Safari, Android/Chrome and WPhone/IEmobile
[16:26] <fmiz> c_14: yes, but even encoding only a video stream sometimes doesn't work
[16:29] <fmiz> c_14: I don't know what happens, one time I run ffmpeg (only video capture) and it will not work, it looks like it isn't capturing any frame (frame counter doesn't change), another time it works flawlessy
[16:29] <c_14> try updating ffmpeg, try adding -flags +global_header, try using the internal aac encoder
[16:29] <c_14> maybe your capture device is doing weird things?
[16:29] <fmiz> c_14: usually stopping and restarting works
[16:30] <fmiz> c_14: I don't know... the capture device is a crappy laptop webcam
[16:30] <c_14> maybe your capture device is doing weird things? <- probably this
[16:30] <fmiz> c_14: Right now I'm testing with this device, how can I check for this weird things?
[16:32] <c_14> hard to tell, you'd have to check the bitstream for corruption
[16:32] <fmiz> c_14: I also tried 2 different versions of ffmpeg (the one in openSUSE 13.1 and the one you see in the pastebin), same issue
[16:32] <fmiz> c_14: what about the other things you suggested? Intenal aac encoder?
[16:33] <c_14> If it happens even when you don't have an audio stream, you can ignore that.
[16:33] <fmiz> Yes, but it looks different
[16:33] <c_14> Different error message?
[16:33] <fmiz> Without audio, ffmpeg runs, it just doesn't get any frame
[16:34] <fmiz> Instead with audio it quits, but I may understand why this happens ("Packets are not in the proper order with respect to DTS")..
[16:35] <fmiz> fflogger: this is the output: http://pastebin.com/7GQgN7AZ
[16:35] <c_14> Not that one, the one without the audio stream.
[16:36] <fmiz> ah.. ok I'm also a noob with irc :D
[16:37] <fmiz> c_14: http://pastebin.com/qvqnuwQe
[16:38] <fmiz> c_14: the test.flv file looks right
[16:39] <c_14> that one looks fine.
[16:39] <c_14> try the other command with -c:a aac -strict -2
[16:39] <c_14> instead of -acodec libwhatever
[16:39] <fmiz> c_14: with aevalsrc ?
[16:39] <c_14> ye
[16:40] <fmiz> c_14: same error as before
[16:40] <c_14> add -flags +global_header
[16:40] <fmiz> c_14: There is something though
[16:40] <fmiz> c_14: My mistake :)
[16:41] <fmiz> c_14: where should I put -flags? Before the first stream input?
[16:42] <c_14> somewhere before the output
[16:42] <fmiz> c_14: same error, should I pastebin?
[16:43] <c_14> sure
[16:44] <fmiz> http://pastebin.com/VJFjwF0z
[16:46] <fmiz> I noticed something: the test.flv file without audio has a little "lag" at the begin of the file
[16:46] <c_14> lag? as in the video is slower at the beginning or it takes a while to display
[16:47] <fmiz> no, it displays immediately
[16:48] <c_14> But doesn't play in realtime?
[16:48] <fmiz> c_14: new test, without audio, but frame count is stuck, output: http://pastebin.com/SGLRTcWV
[16:50] <fmiz> Let's say the video is slower at the beginning
[16:50] <fmiz> it looks more like there are frame drops
[16:51] <fmiz> c_14: this is the output of the last test.flv, that has the "lag" at the beginning http://pastebin.com/992w37TQ
[16:51] <c_14> It looks to me like your webcam isn't producing frames sometimes.
[16:53] <fmiz> in the last ouput I see atleast that the frame output isn't constant
[16:53] <fmiz> This could be fixed using -r before the output?
[16:54] <fmiz> or better before the input?
[16:56] <c_14> try it before the input
[16:57] <fmiz> http://pastebin.com/XW0aSrUf
[16:57] <fmiz> c_14: Still nothing, same error
[17:00] <fmiz> c_14: at least the command I'm using is right? I can test with another webcam, sooner or later, will it work or do you think it can't be done with ffmpeg?
[17:02] <fmiz> c_14: Look at the last pastebin (you can see it also the others), line 15 and 18
[17:02] <fmiz> the error ffmpeg throws as anything to do with it?
[17:02] <fmiz> *has
[17:02] <c_14> it might, try -vf setpts=PTS-STARTPTS
[17:03] <fmiz> before output?
[17:03] <c_14> yep
[17:04] <fmiz> Nope, still the same
[17:05] <fmiz> c_14: http://pastebin.com/YdwWrWF8
[17:07] <c_14> try with this: -filter_complex '[0:v]setpts=PTS-STARTPTS[v]' -map '[v]' instead of the -vf
[17:08] <fmiz> it works but the file has no audio stream
[17:09] <c_14> -map 1:a
[17:09] <c_14> add that as well
[17:09] <fmiz> Same error :)
[17:10] <fmiz> c_14: http://pastebin.com/NUDHQqSQ
[17:16] <c_14> Can you try `ffmpeg -f v4l2 -r 30 -s 640x360 -i /dev/video0 -c copy -t 60 out.mkv' and then `ffmpeg -i out.mkv -f lavfi -i aevalsrc=0 -c:v libx264 -pix_fmt yuv420p -c:a aac -strict -2 out.flv' ?
[17:18] <fmiz> it's working but muxing never ends
[17:18] <fmiz> -shortest?
[17:18] <c_14> eh, ye
[17:19] <fmiz> It works
[17:20] <olavi> Hi, when using ffPLAY for audio  there is a window that pops up with some kind of graph for the audio. from looking in documentation i can see you can change the title of ffplay window, but any way to disable showing the window? or is there some flag to hide the window?
[17:20] <c_14> `ffmpeg -f v4l2 -r 30 -s 640x360 -i /dev/video0 -c copy -f matroska pipe:1 | ffmpeg -i - -f lavfi -i aevalsrc=0 -c:v libx264 -pix_fmt yuv420p -c:a aac -strict -2 out.flv'
[17:20] <fmiz> ok, but I need to stream this thing, so what can I do? I can't use an intermediate file...
[17:20] <c_14> fmiz: pipes
[17:20] <fmiz> c_14: god bless unix pipes :)
[17:20] <c_14> olavi: -nodisp
[17:21] <olavi> c_14: worked like a charm, thanks
[17:22] <fmiz> c_14: Still the same error.
[17:22] <fmiz> It looks like webcam and audio stream can't be processed on the fly.
[17:24] <fmiz> http://pastebin.com/bZD18UW5
[17:24] <c_14> But it worked with the mkv? Did the errors always happen within 60 seconds?
[17:24] <fmiz> It worked with the mkv, I stopped it after 10 sec
[17:25] <c_14> The errors normally occur within 10s ?
[17:26] <fmiz> in much less
[17:26] <fmiz> I think it takes 1 or 2s
[17:26] <fmiz> I'm retesting with you command with out.mkv, 60s
[17:27] <fmiz> It worked
[17:27] <c_14> `ffmpeg -f v4l2 -r 30 -s 640x360 -i /dev/video0 -c libx264 -pix_fmt yuv420p -f matroska pipe:1 | ffmpeg -i - -f lavfi -i aevalsrc=0 -c:v copy -c:a aac -strict -2 out.flv' maybe?
[17:28] <fmiz> You moved the encoding before the pipe?
[17:28] <c_14> yeah
[17:28] <c_14> I don't even know anymore.
[17:28] <fmiz> It's doing something weird
[17:28] <c_14> oh boy
[17:29] <fmiz> I'm testing
[17:30] <fmiz> http://pastebin.com/WCKJTtbX
[17:31] <fmiz> To stop it I first press q, but it won't stop.. it looks like the one of the two ffmpeg stop, the other won't, I had to use Ctrl+c
[17:33] <c_14> Eh, ye. The 2nd process won't quit on q because it doesn't receive it (because it's getting the matroska stream on stdin [you could use fifos to get around this])
[17:33] <c_14> But other than that it works?
[17:33] <fmiz> maybe yes
[17:34] <fmiz> There are no errors, but the outfile has is very long
[17:34] <fmiz> I mean, maybe there are 10s of video, and 2 hours of audio track
[17:35] <fmiz> But I could limit the audio streaming ... what? audio rate?
[17:35] <c_14> add -re before -i aevalsrc=0
[17:36] <fmiz> I think it's working
[17:37] <fmiz> You did it :)
[17:37] <fmiz> Thanks a lot
[17:39] <fmiz> About the fifos... what can I do?
[17:39] <fmiz> Instead of a pipe i redirect the first ffmpeg to a file thats is not a file, then I use that as video source for the 2nd ffmpeg?
[17:39] <c_14> yep
[17:40] <fmiz> (never used fifos before)
[17:40] <c_14> mkfifo foo
[17:40] <c_14> then use foo as output for the first command and foo as the input for the second
[17:40] <c_14> and don't use the | separator anymore
[17:40] <c_14> either start them in separate shells or use & to fork the first one
[17:41] <fmiz> the first ffmpeg still requires pipe:1?
[17:42] <c_14> nah, foo
[17:42] <c_14> (if you did mkfifo foo
[17:42] <c_14> )
[17:42] <c_14> or actually, the full path to foo (or relative)
[17:49] <fmiz> c_14: ok I'm back testing :)
[17:49] <nacho_> hey guys
[17:49] <nacho_> anybody else having this issue building from osx? http://fpaste.org/164330/99581671/
[17:53] <fmiz> c_14: it's working. Thanks, you solved everything :) plus now I know that fifos exist.. That's going to be really useful.
[17:56] <fmiz> c_14: last thing, I probably will need to run something like what you've suggested as a service. What should I do? Create a bash script and run it as a service? I probably will be using systemd
[17:56] <c_14> Ye, something like that probably.
[17:57] <fmiz> or may be use something in python to glue everything together?
[17:57] <c_14> That'll work as well.
[17:58] <fmiz> I'll try and see what's best... I'm still learning python, and I'm not that good with bash script :). Still thank you.
[18:05] <fmiz> c_14: I'm trying the streaming to youtube, it's working. Can I use gpu acceleration to compress video?
[18:05] <c_14> gpu acceleration is mainly useful for decoding video, not for encoding
[18:07] <fmiz> So I just need a fast enough cpu to compress the stream, right?
[18:10] <c_14> yep, you can also change the h264 preset to make it compress faster
[18:10] <c_14> https://trac.ffmpeg.org/wiki/EncodingForStreamingSites
[18:13] <fmiz> c_14: thanks, I already read that. I hoped I could use a GPU to speed up compression to achieve better quality, because probably the pc that will stream will not be that great. At least I'll be able to use a higher bitrate than my dsl
[18:16] <__jack__> c_14: is gpu processing faster than cpu's, with recent GPUs ? with mine (3 years old), opencl is not useful compared to a pure cpu encoding, but maybe that changed (more & more works on such hardware)
[18:17] <c_14> cpu encoders are still better than gpu encoders (in most cases)
[18:19] <BtbN> pure hw encoders are only usefull in some special cases
[18:20] <BtbN> like video game streaming for example, where you need your CPU power for the game. Or streaming to another PC at a high bitrate, which then transcodes to a lower bitrate with a high quality codec.
[18:20] <BtbN> Generaly everything where you don't realy care about the bitrate beeing a bit higher
[18:21] <jarainf> c_14, "generally speaking"
[18:21] <__jack__> what about x264's opencl implementation ?
[18:22] <BtbN> It's not a huge speedup
[18:22] <JEEB> a good proof of concept
[18:22] <JEEB> but not really something you want to use in a production
[18:22] <JEEB> *-q
[18:22] <JEEB> *-a
[18:22] <BtbN> Isn't it used by default, when available?
[18:22] <JEEB> no
[18:22] <JEEB> it's probably built in, but not used
[18:23] <JEEB> (if it finds the opencl related stuff on the system)
[18:24] <BtbN> CUDA/OpenCL Based encoders aren't that powerfull anyway.
[18:24] <BtbN> bothh the intel and nvidia hw encoders use a hardwired pice of hardware for it
[18:24] <JEEB> GPUs are not meant for that kind of processing that is not very, very heavily multithreadable
[18:24] <JEEB> as in, throw thousands of threads at the driver
[18:24] <JEEB> and it will feed the GPU
[18:25] <JEEB> video encoding that is well compressed is not that kind of stuff
[18:25] <BtbN> Which is why they add special chips for that
[18:25] <JEEB> the stuff the opencl thing for x264 does is very limited and is one of those things where you can do stuff separately from the rest (to a limit)
[18:25] <JEEB> yup
[18:25] <JEEB> everyone understood that the kool-aid was getting warm
[18:26] <BtbN> I realy need to get a new nvidia card
[18:26] <JEEB> and not only the server rooms with expensive heaters that the PR departments were able to sell :P
[18:26] <BtbN> i want to look at that h265 hw encoder
[18:26] <__jack__> JEEB: bad-compressed encoding can be usefully speed-up, you means ? :)
[18:26] <JEEB> __jack__, yes - ATi made their own format which was simple as hell and intra-only methinks
[18:26] <JEEB> and that was quite fast
[18:27] <JEEB> basically you have to make the format around what the GPU can do :P
[18:27] <JEEB> BtbN, I don't think the HEVC encoder components are on actual hardware yet
[18:28] <BtbN> yes they are
[18:28] <BtbN> the newest maxwell generation has them
[18:28] <BtbN> so, the 900 gtx cards
[18:28] <__jack__> BtbN: encoder or decoder ?
[18:28] <JEEB> but yeah, ASICs usually aren't geared for compression
[18:28] <BtbN> encoder
[18:28] <JEEB> so you might get alright speeds, but not really compression
[18:28] <JEEB> might be fun to test if you need the card for other things, too
[18:28] <JEEB> but not worth buying the card for just the ASIC
[18:29] <BtbN> "Support for HEVC (H.265) encoding on GM20x GPUs (GTX980 and future Quadro/Tesla/GRID platforms based on GM20x GPUs)"
[18:29] <BtbN> Aparently it's only the 980
[18:30] <JEEB> yeah, but I think they added HEVC support for decoding as well, but that was at least partially software if not fully. so they might have just added a CABAC encoder or something there :3 not that I know
[18:30] <BtbN> Yeah, but h265 decoding is supported by all maxwell cards
[18:30] <JEEB> an ASIC CABAC coder would be pretty cool, though
[18:30] <BtbN> encoding is 980gtx only
[18:30] <JEEB> although probably not on a GPU :/
[18:30] <JEEB> too much latency
[18:32] <BtbN> nvenc is extremely usefull for video game streaming. As it can use OpenGL/Direct3D framebuffers as input
[18:32] <BtbN> So you can encode the game without the frames ever leaving the vram
[18:32] <BtbN> They use that for their ultra-low-latency game streaming
[18:33] <JEEB> yeah
[18:33] <JEEB> for that kind of stuff it's quite useful
[18:33] <JEEB> it'd be even more if it had a lossless mode
[18:33] <JEEB> RGB or YCbCr
[18:33] <BtbN> The api has a lossless mode
[18:33] <BtbN> but so far it's not implemented by the hardware
[18:34] <BtbN> But i think the new maxwell generation added YUV 4:4:4 lossless mode
[18:34] <__jack__> I don't think GPUs will produce a better HEVC output than x265; it's the eternal fight, software vs hardware; software will always be, in practical, better than hardware, because it is easier and can be patched; well, it's usefull sometime, still
[18:35] <BtbN> Well, but they will encode it in real time without needing 16+ cores
[18:35] <BtbN> And propably at a better quality/lower bitrate than h264
[18:35] <JEEB> well, that we will see when the HEVC encoders get more mature
[18:35] <JEEB> currently even the sw implementations are having problems with beating x264
[18:36] <BtbN> That's why i'm so curious about what this nvidia encoder is capable of
[18:36] <JEEB> but yeah, the bottom line is that no useful ASIC will produce better compression than software encoders, but if you have specific needs they can be quite useful
[18:38] <BtbN> nvidia primarily added the encoder chip for their Game Streaming products. The encoder was originaly not intended to be useable individualy.
[18:39] <BtbN> When i first got in touch with nvenc, i had to contact nvidia for a license key.
[20:13] <myndzi> i'm looking for a way to filter a capture or webcam source through some stuff to clean up the video and output another video or webcam source; know of anything like this?
[23:54] <shevy> are there any examples out there how to use ffmpeg filter capabilities?
[23:54] <shevy> for instance, "blur a video by 1 pixel" or something like that
[23:55] <c_14> https://trac.ffmpeg.org/wiki/FilteringGuide
[23:55] <shevy> cool thanks c_14
[23:56] <shevy> whoa.. about 180 filters
[00:00] --- Wed Dec 31 2014