[Ffmpeg-devel-irc] ffmpeg.log.20151003

burek burek021 at gmail.com
Sun Oct 4 02:05:01 CEST 2015

[00:07:11 CEST] <djems54> Hi, how best ffserver stream between two ffservers? The idea is to be able to multiply the number of ffserver to support a greater load
[00:26:58 CEST] <pinPoint> do the projects from google summer of code get added into ffmpeg eventually?
[00:27:11 CEST] <c_14> For the most part, yes.
[00:29:14 CEST] <pinPoint> I had an idea couple weeks ago. I live in an area where over the air tv is not available via antenna. Maybe 2 channels. I was thinking of putting a computer in another city, 1hr away, with an antenna capturing channels and sending them over the internet. On my side I would use some sort of receiver to tap into the broadcast and watch tv.
[00:30:11 CEST] <pinPoint> after seeing the project from S.O.C that is looking like what I've wanted to do
[00:30:27 CEST] <c_14> Which project?
[00:31:05 CEST] <pinPoint> the one on the front page of ffmpeg.org
[00:32:29 CEST] <c_14> The network protocol one?
[00:32:34 CEST] <pinPoint> ya
[00:33:00 CEST] <c_14> Well, the single-client part works
[00:33:08 CEST] <pinPoint> just don't know how one would change the channel remotely from far away. If the computer can see many channels
[00:33:26 CEST] <pinPoint> it is a wild idea, like what Aereo had going.
[00:33:31 CEST] <iive> there are other solutions that might work better
[00:33:49 CEST] <pinPoint> yeah, there is a box that streams to the web. I saw it somewhere
[00:34:15 CEST] <iive> check sat-ip , or the linux program tvheadend
[00:37:43 CEST] <pinPoint> iive: how does sat-ip work exactly?
[00:38:29 CEST] <iive> it's more like a protocol. i haven't used it, but i've heard about it.
[00:38:35 CEST] <iive> check wikipedia
[01:36:48 CEST] <pinPoint> according to https://ffmpeg.org/ffmpeg-codecs.html#ProRes there are 2 prores encoders. I thought there was three prores, prores_aw and prores_ks
[01:37:32 CEST] <pinPoint> or is it because prores_aw is the same as prores that makes it two?
[01:48:36 CEST] <c_14> I think prores is an alias of one of the others
[03:07:23 CEST] <mertin2> Can someone help me with this? I'm trying to convert a bunch of
[03:07:23 CEST] <mertin2>     images to video. My files are named 0_img.png, 1_img.png,
[03:07:23 CEST] <mertin2>     2_img.png, ... 99_img.png. I'm trying to follow the wiki tutorial
[03:07:23 CEST] <mertin2>     but I think the provided command doesn't like that some images are
[03:07:25 CEST] <mertin2>     0_img.png instead of 000_img.png, for example.
[03:08:47 CEST] <mertin2> The command I'm using is ffmpeg -framerate 1/5 -i %03d_img.png -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4
[03:09:23 CEST] <c_14> You'll have to use glob, or rename the input files
[03:11:26 CEST] <mertin2> hmm that gave me "'*.png': Invalid argument"
[03:11:39 CEST] <c_14> Did you use -pattern_type glob ?
[03:11:55 CEST] <c_14> Might have to add -f image2
[03:11:57 CEST] <mertin2> yes
[03:12:01 CEST] <mertin2> ffmpeg -framerate 1 -pattern_type glob -i '*.png' -c:v libx264 -pix_fmt yuv420p out.mp4
[03:12:01 CEST] <drv> %d_img.png should work (instead of %03d)
[03:12:12 CEST] <c_14> Oh, yeah. It should
[03:12:30 CEST] <mertin2> yes, working!
[03:12:36 CEST] <mertin2> can you explain why?
[03:12:47 CEST] <c_14> %d?
[03:12:48 CEST] <drv> the %03d means "format number with 3 digits, pad with 0s"
[03:12:58 CEST] <drv> %d is just a plain number without any padding
[03:13:31 CEST] <mertin2> what ensures that it prcoess the files in the desired order? 0,1,2,...,99 ?
[03:14:44 CEST] <c_14> 9 + 1 = 10; 10 + 1 = 11
[03:14:46 CEST] <c_14> etc
[03:15:57 CEST] <c_14> starts at 0 and increases until it can't find the next number anymore (unless you use -start_number in which case it starts there)
[03:16:38 CEST] <mertin2> ok, thanks
[03:31:15 CEST] <mertin2> if I want to extract an image for every frame in a video, I could follow the instructions for "Output one image for every I-frame"?
[03:31:24 CEST] <mertin2> (I'm not sure what an I_frame is)
[03:31:35 CEST] <c_14> ffmpeg -i video out%03d.png
[03:31:37 CEST] <c_14> etc
[03:32:43 CEST] <mertin2> ah, many more "Frames" than "I-frames"
[03:40:18 CEST] <razzledazzle> hello guys, what filter might be necessary to process videos that have rotation metadata? also are filters required for decoding?
[03:40:39 CEST] <c_14> If you use recent versions of ffmpeg, none.
[03:41:07 CEST] <razzledazzle> I'm compiling a minimal ffmpeg binary
[03:42:24 CEST] <razzledazzle> I've excluded a lot of filters and it works with regular videos, but the ones with the rotation side data echo error "error opening filters", I've tried the rotation filter which doesn't work, I'm not sure what is needed for this
[03:43:20 CEST] <razzledazzle> now I've included all the filters and it works nicely, but I'd like to cut down on most of them
[03:46:27 CEST] <c_14> It should just be the rotate filter.
[03:51:16 CEST] <n0tmE> merlin, have you tried video filter? https://trac.ffmpeg.org/wiki/FilteringGuide, search for PICT_TYPE_I
[03:51:30 CEST] <n0tmE> sorry, *mertin
[03:57:21 CEST] <razzledazzle> c_14: I tried the rotate filter, it didn't work
[04:01:19 CEST] <c_14> Ah, right. Duh. It also uses transpose, hflip and vflip depending on the angle.
[04:01:47 CEST] <razzledazzle> I'll include them and try now :)
[04:03:33 CEST] <razzledazzle> c_14: but the resulting video is in resolution 640x480, which when played gets rotated to 480x640, is the encoder really doing all that?
[04:04:02 CEST] <c_14> hmm?
[04:04:35 CEST] <razzledazzle> I'll do some pasting
[04:08:39 CEST] <razzledazzle> c_14: I don't think its doing any rotation, http://pastie.org/private/pwaiji8ngzu76iqh0dik6g
[04:09:57 CEST] <c_14> Right, because of the displaymatrix side data of -90 degrees
[04:11:09 CEST] <razzledazzle> yes, I don't know why it needs filters at all
[04:39:02 CEST] <razzledazzle> c_14: only needed transpose :D
[04:39:16 CEST] <c_14> Because of the 90 degree angle, sure.
[04:40:19 CEST] <razzledazzle> but why? rotation should only be the reponsibility of the player yes? even the encoder is not doing any kind of transformation
[04:40:59 CEST] <c_14> Because nobody likes unrotated video. If you don't want ffmpeg to rotate the video add -noautorotate
[04:42:43 CEST] <razzledazzle> it works as intended now, I'm only curious, that too does look like an option that might be needed someday
[07:54:13 CEST] <spiderkeys> Hi all, I'm trying to wrap an H264 stream in an MP4 container and am trying to get as low a latency as possible. Right now, I'm seeing latencies of around 180ms using the following: http://pastebin.com/hYT7p5FX
[07:54:28 CEST] <spiderkeys> Are there any obvious ways to improve the latency on the receiving end?
[07:55:02 CEST] <spiderkeys> sorry, as the server doing the wrapping, not the receiving
[09:54:05 CEST] <xerox> hi. original: http://pastebin.com/raw.php?i=V9r6aL7q my encode: http://pastebin.com/raw.php?i=cGufaNyp a number of questions: should I have the same ReFrames? why does GOP disappear? why does the frame rate change? should I use some option to get the same fps settings in the output?
[11:18:20 CEST] <orione1> hi
[11:23:07 CEST] <orione1> i'm trying to transcode avi files to mp4/webm and show them into html video tag during transcoding with no luck. Maybe the way is in this guide: https://trac.ffmpeg.org/wiki/StreamingGuide but i can understand how to put server response in html tag
[11:26:48 CEST] <choki> Hi there, any chance I can create such video without definitions foreach image? http://superuser.com/questions/833232/create-video-with-5-images-with-fadein-out-effect-in-ffmpeg
[11:27:24 CEST] <choki> The reason is, I've lot of images and writing for each image a single filter seems to be wrong.
[13:47:59 CEST] <ChocolateArmpits> Does anyone what is this in any greater detail ? http://aomedia.org
[13:48:23 CEST] <ChocolateArmpits> >The initial project will pursue a new, open royalty-free video codec specification and open-source implementation based on the contributions of members
[13:54:59 CEST] <iive> ChocolateArmpits: that's an old news: http://lwn.net/Articles/656288/
[14:00:26 CEST] <grublet> but we already have vp8/opus/webm
[14:00:30 CEST] <grublet> why another
[14:05:03 CEST] <ChocolateArmpits> iive: 2 days i hardly old
[14:05:17 CEST] <iive> ChocolateArmpits: 2 days and one month
[14:05:28 CEST] <RobotsOnDrugs> grublet: perhaps this https://imgs.xkcd.com/comics/standards.png
[14:05:30 CEST] <ChocolateArmpits> iive: oh dog I live in the past
[14:05:37 CEST] <iive> :P
[14:05:38 CEST] <ChocolateArmpits> I forgot it's October already
[14:05:57 CEST] <iive> yeh, september went out so quickly
[14:07:22 CEST] <RobotsOnDrugs> lol the first comment on that lwn page has exactly what i thought of
[14:22:02 CEST] <grublet> RobotsOnDrugs: that comic was precisely what i had in mind
[14:22:55 CEST] <grublet> i guess free market capitalist ideaology applies to communal software as well
[14:36:16 CEST] <girlz_baby> hi
[14:36:32 CEST] <durandal_1707> hi
[14:36:50 CEST] <girlz_baby> durandal r u a botm
[17:52:53 CEST] <foreverska> I'm trying to compile with libnvenc but I get unknown option
[18:07:42 CEST] <BtbN> There is no libnvenc. What are you actualy trying to do?
[18:09:27 CEST] <foreverska> Enable Nvidia encoding for h264
[18:12:28 CEST] <BtbN> The configure option for that is --enable-nvenc, if that's what you have trouble with?
[18:13:13 CEST] <foreverska> It seems to like that.  Just have to finish linking the decklink API before I'll know for sure.
[18:13:45 CEST] <BtbN> Could have just looked at --help
[18:14:01 CEST] <foreverska> lol in my defense --help has a LOT of options
[18:14:11 CEST] <BtbN> | grep nvenc
[18:14:28 CEST] <foreverska> lol yea...
[18:14:30 CEST] <BtbN> I think nvidia is also in the description
[18:48:55 CEST] <foreverska> is qsv a decent boost compared to CPU?
[19:39:47 CEST] <_0x5eb_> hi, is there a way to get the list of codec-specific options with ffmpeg executable?
[19:41:26 CEST] <DHE> ffmpeh -h full   # and go find the codec you want
[19:41:32 CEST] <DHE> fix obvious typo
[19:42:15 CEST] <_0x5eb_> DHE, great thanks a lot!
[19:43:59 CEST] <_0x5eb_> so I guess that if a codec is no listed, there is no chance that it supports any private option, right?
[19:44:08 CEST] <Mavrik> Well.
[19:44:23 CEST] <Mavrik> Look at <codec>.c or <codec>enc.c in libavcodec source to be sure
[19:44:34 CEST] <c_14> ffmpeg -h encoder=blah; ffmpeg -h decoder=blah
[19:46:30 CEST] <_0x5eb_> Mavrik, c_14: thanks, so both confirm that there is no private option for libschroedinger
[21:29:44 CEST] <foreverska> Shoot, it's reporting that I don't have any NVENC capable devices.  I have two GTX660s, that can't be true
[22:36:36 CEST] <foreverska> I've installed the latest drivers and jacked around with my xorg many times and I still get "No NVENC capable devices found" when I have twin GTX 660s sitting here.
[00:00:00 CEST] --- Sun Oct  4 2015

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