[Ffmpeg-devel-irc] ffmpeg.log.20150724

burek burek021 at gmail.com
Sat Jul 25 02:05:01 CEST 2015

[02:30:45 CEST] <dirty_d> lenscorrection is the best filter to use to correct for gopro fisheye right?
[03:19:55 CEST] <ig0r_> I get an error message what did I do wrong? http://pastebin.com/KMGCJMGt
[03:23:20 CEST] <klaxa> you must use -c copy not only copy
[03:24:33 CEST] <dirty_d> c:v is all lonely too
[03:25:35 CEST] <ig0r_> I want to join a video stream and an audio stream into an mp4 file. please tell me how :)
[03:27:40 CEST] <ig0r_> english is not my first language so if someone could just tell me the correct commands please :)
[03:28:48 CEST] <dirty_d> -c:v copy
[03:28:52 CEST] <dirty_d> you have them separated
[03:29:45 CEST] <ig0r_> I don't know what you mean :(
[03:30:43 CEST] <dirty_d> ffmpeg.exe -i v:\video.h264 -i v:\audio.ac3 -c:v copy -c:a copy v:\result.mp4
[03:30:48 CEST] <dirty_d> try that
[05:54:05 CEST] <podman> Does anyone have any experience setting up WideVine or PlayReady or other DRM?
[08:27:49 CEST] <QQ> Hello. I have a question. I'm using the concat demuxer to concatenate files. Everything works perfect, except I don't know how to keep the metadata of the files. The command I'm using is "ffmpeg -f concat -i list.txt -c copy destination.mp3" (also tried flac files, but without the "-c copy" part). The files are merged, but even though they all have the same metadata not metadata at all is kept. How can I do that?
[08:27:51 CEST] <QQ> The content of my list.txt file are "ffconcat version 1.0" (first line), and then for each file I set filename, duration, inpoint and outpoint.
[08:54:01 CEST] <k_sze[work]> Wasn't there an ffmpeg option to output some stats and CRC about the frames, instead of actually getting pixel data? I can't remember what it is.
[08:54:15 CEST] <k_sze[work]> And I can't quite find it in the man page either.
[09:35:24 CEST] <QQ> I found out that I can use "-i filewithmetadata.flac -map_metadata:g:0 1:g", and it works with the flac file; it retains the metadata from the original file. But it doesn't work with mp3. Does anyone know why?
[09:43:50 CEST] <durandal_1707> k_sze[work]: -vf showinfo ?
[10:00:32 CEST] <QQ> I got everything to work. Sorry for bothering.
[10:04:35 CEST] <durandal_1707> QQ: how?
[10:05:23 CEST] <Mista_D> can someone point to an instruction for mfx
[10:08:38 CEST] <Mista_D> http://pastebin.ca/3072944  - keep getting configure error: "ndefined reference to `MFXInit'"
[10:38:35 CEST] <raven737> Hi, quick question, what are the _g files when i make (build) the source?
[10:41:03 CEST] <JEEB> in case you are building so that you are stripping debug symbols, the _g binaries still have them
[10:41:14 CEST] <JEEB> if you disable stripping then the final binaries will have them
[10:46:18 CEST] <raven737> JEEB: thank you!
[11:17:14 CEST] <martijnB> I think I'm misunderstanding something, I'm trying to set up ffserver with HLS, after trying to configure the stream in the .conf (ie. setting Format hls, AVOptionVideo hls_time 10) the server won't launch reporting errors like Option not found: 'hls_time'
[11:17:54 CEST] <martijnB> I thought that was the right place to configure it, and the right option, I can't figure out why it would come up as not found
[12:52:27 CEST] <pragomer1> hello. what is the best ppa for ffmpeg for ubuntu 14.04 ?
[18:15:03 CEST] <benbro1> can ffmpeg use pcap or rtpdump files?
[18:25:34 CEST] <durandal_1707> benbro1: currently not
[18:27:12 CEST] <benbro1> durandal_1707: thanks
[18:27:27 CEST] <benbro1> durandal_1707: can I pipe rtp/rtcp packets instead of using udp?
[19:02:00 CEST] <durandal_1707> benbro1: dunno
[19:21:53 CEST] <ChocolateArmpits> I started reading UHD Guidebook by Harmonic and about Rec709 it mentions "Current television and Blu-ray standards limit maximum brightness to 100 nits and minimum brightness to 0.117 nits"
[19:21:59 CEST] <ChocolateArmpits> Does anyone what those 100 nits are about ?
[19:22:24 CEST] <ChocolateArmpits> You can find the doc at this link: http://www.harmonicinc.com/sites/default/files/Harmonic_Complete_UHD_Guidebook.pdf
[19:30:05 CEST] <JEEB> ChocolateArmpits: I will guess it's a roundabout way of saying that you have to use limited range, 8bit and BT.709 YCbCr
[19:30:18 CEST] <JEEB> because after that it starts talking about BT.2020 YCbCr
[19:31:26 CEST] <ChocolateArmpits> JEEB: But it's rather specific. I thought maybe the 100 nits are related to tests done to determine optimum transform in common viewing environments ?
[19:32:04 CEST] <JEEB> no idea, as far as I know the specs don't say jack shit about that. All they care is that you're within limited range and are using BT.709 YCbCr colorimetry
[19:35:27 CEST] <ChocolateArmpits> Well yeah, because nits are not a digital measurement
[20:51:14 CEST] <Mista_D> what's the quick option to map first four audio tracks even if the source has only two?
[20:53:30 CEST] <JEEB> I would recommend using a probing pass first and building your command line on that
[20:55:33 CEST] <Mista_D> JEEB: it takes half a page of script ... thougth there was somethign faster, thanks anyways.
[20:55:44 CEST] <JEEB> uhh
[20:55:51 CEST] <JEEB> you do know that ffprobe can give you JSON?
[20:55:52 CEST] <JEEB> right
[20:56:17 CEST] <JEEB> and if whatever you're using takes half a page of script to parse json variables, then you're doomed :3
[20:56:25 CEST] <Mista_D> lol
[21:53:12 CEST] <bencc> how can I feed RTP packets to ffmpeg other than udp?
[21:53:30 CEST] <bencc> can I somehow push pcap or rtpdump file to ffmpeg?
[22:05:23 CEST] <Mista_D> MFS error with QSV: http://pastebin.ca/3073652
[22:05:33 CEST] <Mista_D> MFX *
[22:06:22 CEST] <Nolski> Anyone here have experience with MLT rendering? I'm thinking if it's possible it might be easier to find some sort of headless renderer and feed it some sort of markup of edits rather than writing my own
[23:08:45 CEST] <Nolski> Anyone know of a good way to render a list of ffmpeg commands but only re-encode the video once? I'm worried about losing lots of quality by running ffmpeg a bunch of times on one video
[23:09:43 CEST] <Nolski> s/lots/loss/
[23:10:00 CEST] <chungy> make sure to do -c:v copy then
[23:11:17 CEST] <Nolski> chungy: quick explanation of what that means?
[23:11:32 CEST] <chungy> It just copies the video stream instead of re-encoding it
[23:12:22 CEST] <Nolski> what if you're rendering video on top of another one or trimming something or using -filter_complex?
[23:17:14 CEST] <Nolski> chungy: ^
[23:18:02 CEST] <chungy> then you can't do that. Try to compact all the stuff into a single command if you can.
[23:18:36 CEST] <chungy> Alternatively, use a lossless video codec in the interim. something like "-c:v ffvhuff" or "-c:v h264 -qp 0"
[23:19:03 CEST] <Nolski> chungy: h264 is lossless?
[23:20:36 CEST] <chungy> Can be
[23:20:58 CEST] <chungy> -qp 0 makes it lossless
[23:21:18 CEST] <Nolski> neat
[23:21:53 CEST] <pzich> it'll also make a pretty huge file though
[23:22:27 CEST] <Nolski> That shouldn't be too much of a problem. I'll be deleting the file once the edits are finished.
[23:22:36 CEST] <chungy> Yeah, lossless is huge :P
[23:22:46 CEST] <Nolski> Shouldn't tooling for this sort of stuff exist already?
[23:23:04 CEST] <Nolski> Like a giant ffmpeg wrapper where you just send it an xml or json of edits to some video files and it does it for you?
[23:23:34 CEST] <Nolski> I can't find anything that does that that is FOSS.
[23:31:47 CEST] <chungy> good idea, I don't know any myself
[23:32:08 CEST] <chungy> I've tended to make ad-hoc shell scripts every time I'm doing large batch operations (like converting TV series from DVD to *.mkv files...)
[23:32:43 CEST] <Nolski> chungy: yeah same here. Now I'm working on a script that's output by an in browser video editor so this shell script is turning into a very large python application haha.
[23:35:12 CEST] <chungy> haha
[23:38:51 CEST] <chungy> I was kind of proud of my script for Star Trek TNG... it would fetch the episode title, season number, and episode number from a psql database I have, and tag it and name the file in the proper way to minimize the chance of errors. Of course I deleted it when I was done with it. heh
[00:00:00 CEST] --- Sat Jul 25 2015

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