[Ffmpeg-devel-irc] ffmpeg.log.20171027

[burek]

[00:01:04 CEST] <__jack__> mpv is simply better than mplayer, today
[00:01:09 CEST] <Polochon_street> hi, is there a way to display a live spectrogram (like in ffplay) of something played in pulse?
[00:02:02 CEST] <durandal_1707> no
[00:02:44 CEST] <durandal_1707> you mean pulseaudio?
[00:02:59 CEST] <Polochon_street> yep, like using the pulse sink and doing a « real-time » spectrogram
[00:03:33 CEST] <durandal_1707> write pulse sink
[00:03:52 CEST] <durandal_1707> i dunno if one exist already
[00:05:27 CEST] <Polochon_street> hm, alright, because the idea was to have like a microphone input that could be handled by ffmpeg and display the real-time spectrogram of it
[00:05:36 CEST] <Polochon_street> but I guess I'll have to put my hands in it and it's not trivial to do :D
[00:06:00 CEST] <durandal_1707> Polochon_street: ffmpeg have filter already
[00:08:56 CEST] <Polochon_street> durandal_1707: you mean to have a spectrogram? Yeah, I was just wondering whether I could do that directly on a « live » stream
[00:09:49 CEST] <durandal_1707> there is A->V filter,
[00:11:11 CEST] <durandal_1707> showspectrum
[00:12:31 CEST] <Polochon_street> okay, I'll investigate there, if it's possible. Just wanted to know that, thanks :)
[00:40:39 CEST] <Polochon_street> argh, almost there but 'ffplay -f pulse -i alsa_output.usb-DAC_FOR_USB_FOCAL_XS-00.analog-stereo.monitor -af showspectrum' complains about mismatches between audio/video
[00:40:49 CEST] <Polochon_street> I'm missing something somewhere, but can't manage to find it :(
[00:45:28 CEST] <Polochon_street> and without the -af showspectrum it shows the spectrum, weird
[18:04:37 CEST] <danieel> how can i specify ffmpeg input for a uncontained compressed bitstream? (i have some prores raw data which i want to either embed to mp4 or decode do stills)
[18:41:58 CEST] <relaxed> danieel: try the rawvideo demuxer, "ffmpeg -h demuxer=rawvideo", along with -vcodec prores
[19:05:05 CEST] <kepstin> rawvideo is intended for uncompressed frames, I don't think that'll work. First just check with "ffmpeg -i filename" to see if it can probe the bitstream automatically, if it can, you're good
[19:07:38 CEST] <kepstin> i didn't even know there was a raw prores bitstream format
[19:07:49 CEST] <kepstin> i guess there is.
[19:20:32 CEST] <kepstin> if the prores decoder can handle unparsed data, you could try with "-f data -c:v prores" and hope for the best
[19:21:02 CEST] <JEEB> I've only seen prores in MOV to be honest, but since it's an intra only format...
[20:18:41 CEST] <fauxton> Hello guys, I'm trying to transcode an audio file into a .qcp   is there any easy way to do this?  I have the source in wav and mp3
[20:19:56 CEST] <durandal_1707> no
[20:20:10 CEST] <furq> fauxton: there's no encoder for any of the codecs it supports
[20:20:32 CEST] <sfan5> ffmpeg does not seem to have a muxer for it either
[20:22:22 CEST] <fauxton> hmm.  I see a few sketchy standalone programs online but I don't trust them to be clean and honest
[20:22:56 CEST] <JEEB> huh https://wiki.multimedia.cx/index.php?title=QCP
[20:23:05 CEST] <JEEB> why requiring such a specific format?
[20:23:08 CEST] <Johnjay> What's QCP? could an encoder be written for it?
[20:23:09 CEST] <fauxton> I didn't see any plugins for audition either
[20:23:30 CEST] <fauxton> its for an old cell phone, that's the only thing it will use
[20:23:34 CEST] <JEEB> rip
[20:23:44 CEST] <JEEB> and AMR in 3gp file doesn't work+
[20:23:45 CEST] <JEEB> ?
[20:24:35 CEST] <fauxton> Haven't tried that
[20:24:57 CEST] <JEEB> that's what my old old phone that supported any sort of non-MIDI audio files supported
[20:25:14 CEST] <furq> it's some qualcomm format so i'm guessing there's not much if anything other than old phones that can create them
[20:25:43 CEST] <JEEB> although to be honest if you renamed an mp4 "m4a" my old old phone would eat that, too
[20:25:57 CEST] <furq> yeah it must be super old if it doesn't even take aac-lc in m4a
[20:26:04 CEST] <furq> or m4a renamed to 3gp
[20:27:10 CEST] <fauxton> true, yeah I used to change from 3gp to m4a back when you could pull youtube videos out of chrome's cache
[20:27:15 CEST] <Johnjay> heh, my modern mp3 player I bought last week only takes wma, mp3, or wav.
[20:27:22 CEST] <Johnjay> not even a .mp3 remaned as .mp4
[20:27:44 CEST] <fauxton> alright, trying the 3gp
[20:28:38 CEST] <JEEB> Johnjay: what we talked about are things generally sharing structure, mp3 and mp4 are completely different structurally
[20:28:47 CEST] <JEEB> mp3 is *raw* MPEG-1 Layer 3 audio
[20:28:50 CEST] <JEEB> (no container)
[20:28:57 CEST] <furq> usually with an id3 tag welded onto the front
[20:29:17 CEST] <JEEB> mp4 is usually an ISOBMFF container (colloquially called "mp4")
[20:29:26 CEST] <Johnjay> JEEB: oh ok. i was thinking in terms of, try to play anything ignoring the file extension.
[20:29:26 CEST] <furq> usually?
[20:29:27 CEST] <JEEB> (ISOBMFF = ISO Base Media File Format)
[20:29:46 CEST] <JEEB> furq: in theory you could have someone do something stupid :P
[20:29:58 CEST] <JEEB> or have a file that is not valid according to latest ISOBMFF spec
[20:30:00 CEST] <furq> i guess we are talking about china MP4 players
[20:30:02 CEST] <JEEB> but which was valid for mov
[20:30:04 CEST] <JEEB> no
[20:30:08 CEST] <furq> everything is possible when those guys are in town
[20:30:08 CEST] <JEEB> that's a separate headache :D
[20:30:19 CEST] <Johnjay> my mp3 player is from china. as is everything else we have in america.
[20:30:22 CEST] <furq> including the beloved MP5
[20:30:23 CEST] <JEEB> it was mostly a technicality thing
[20:30:34 CEST] <furq> i think i still have an MP5 PLAYER somewhere
[20:30:41 CEST] <furq> or i might have given it to my old flatmate when i got a sansa fuze
[20:30:56 CEST] <furq> it was actually reasonably competent
[20:31:38 CEST] <fauxton> it's weird there are some online converters that will read QCP but only read and not write
[20:31:47 CEST] <furq> ffmpeg will apparently read it
[20:31:51 CEST] <furq> it at least has decoders for the codecs
[20:31:52 CEST] <fauxton> the 3gp didn't work, at least the way I did it
[20:31:59 CEST] <furq> so i'm guessing those guys are just using ffmpeg
[20:32:05 CEST] <fauxton> haha
[20:32:16 CEST] <furq> everyone else is anyway
[20:32:24 CEST] <fauxton> might as well
[20:33:39 CEST] <furq> if it's good enough for youtube, it's good enough for DANNYSOFT.RU MAGIC ONLINE MEDIA   ",
[20:34:55 CEST] <Johnjay> lol..
[20:35:49 CEST] <Johnjay> furq: that really underlies the significance of power struggles like the libav thing
[20:36:04 CEST] <Johnjay> so many people use a thing like ffmpeg, even if it's free, that if it gets co-opted or taken over
[20:36:16 CEST] <Johnjay> that could have bad effects over a lot of sites
[20:36:33 CEST] <Johnjay> although you can always fork a GPL project i suppose
[20:38:18 CEST] Action: Johnjay ponders firefox webextension and version 57 which will break tons of add-ons...
[20:39:30 CEST] <furq> i'm already using 57 and it's fine
[20:42:22 CEST] <thegrif> ffmpeg is kicking my ass...i have a big mp4 (140mb)...want to spit out a small mp4, ogv, and webm for use as a background video on a website...trying to get the individual files under 1mb...if anyone is around I'd gladly buy you a pizza :)
[20:43:00 CEST] <sfan5> use 2pass encoding
[20:43:09 CEST] <sfan5> and don't bother with ogv, webm+mp4 covers 99% of browsers
[20:43:12 CEST] <furq> i don't think you need ogv any more
[20:43:12 CEST] <furq> yeah
[20:43:51 CEST] <furq> webm+mp4 covers all browsers released in the last several years
[20:44:01 CEST] <furq> i think ogv was only ever needed for like two versions of firefox
[20:45:04 CEST] <thegrif> i'm doing a two pass on the webm
[20:45:27 CEST] <furq> there's not really much you can do to get the mp4 smaller other than preset and crf
[20:45:38 CEST] <thegrif> I took the original mp4 and then dumbed that down to a 1.1mb mp4...then I'm generating the webm off of that
[20:45:43 CEST] <furq> oh
[20:45:44 CEST] <furq> yeah don't do that
[20:45:54 CEST] <thegrif> I should generate it off the original?
[20:45:56 CEST] <furq> yes
[20:46:03 CEST] <furq> otherwise you're encoding compression artifacts
[20:46:21 CEST] <furq> which ironically do not compress well
[20:46:33 CEST] <thegrif> that makes sense
[20:47:09 CEST] <furq> i guess you could also reduce the size and have the player stretch it
[20:47:12 CEST] <thegrif> use VP9 for the webm?
[20:47:14 CEST] <furq> that usually helps a lot
[20:47:15 CEST] <furq> and yeah, vp9
[20:47:22 CEST] <furq> you don't really need webm iirc
[20:47:51 CEST] <furq> everything supports mp4 by default but some weird browsers disable h264 decoding for patent reasons
[20:48:01 CEST] <furq> vanilla chromium for one
[20:48:06 CEST] <thegrif> i got a wordpress theme that is asking for the background video in the three formats
[20:48:09 CEST] Action: thegrif shrugs
[20:48:12 CEST] <furq> oh
[20:48:22 CEST] <furq> well yeah you might as well give it any old ogv because nobody's going to see it
[20:48:40 CEST] <furq> the webm should be smaller for the same quality so you might as well use that to save bandwidth
[20:53:52 CEST] <fauxton> well guys I found an old qualcomm program for XP that let me convert my file to qcp but it mashes the 2.2 second clip into 4k and it sounds like crap.  There's no real quality settings
[20:54:32 CEST] <sfan5> unsurpising since qcelp is a codec meant for voice transmission at phone quality levels
[20:54:58 CEST] <fauxton> I had some other program for my previous phone that did the conversion without saying anything and put it directly on the phone and that sounded better.  Maybe there is some other file the darn thing will accept
[20:55:22 CEST] <sfan5> it might accept other codecs that sound better
[20:55:33 CEST] <thegrif> ok - so I have a 71s video that I want to get down to 1mb or smaller...so I target a bitrate of 115? does that make sense?
[20:55:39 CEST] <thegrif> and then I'll run a two-pass job?
[20:55:44 CEST] <fauxton> I wonder how I find out what codecs haha
[20:57:12 CEST] <sfan5> thegrif: not sure which dimensions/content your video has but 115 is extremely low of a bitrate for any video
[20:57:27 CEST] <sfan5> e.g. the average audio stream has more kbit/s than that
[20:57:27 CEST] <thegrif> yeah - thats what I was thinking when I first saw it :-/
[20:58:01 CEST] <sfan5> you might want to target e.g. 10mb instead
[20:58:23 CEST] <furq> 4MB is probably fine for a background video of that length
[21:20:06 CEST] <DHE> unless you're at something tiny like 240x160
[23:18:38 CEST] <Johnjay> furq: I was thinking of things like greasemonkey and other extensions. Can you install GM?
[23:19:16 CEST] <JEEB> https://docs.google.com/spreadsheets/d/1TFcEXMcKrwoIAECIVyBU0GPoSmRqZ7A0VBvqeKYVSww/view
[23:19:20 CEST] <JEEB> this is a very useful document
[23:20:00 CEST] <furq> Johnjay: no
[23:20:05 CEST] <furq> but you can install tampermonkey
[23:20:20 CEST] <furq> which has the same script api
[23:21:11 CEST] <Johnjay> JEEB: I note about half of those haven't been fully ported yet
[23:22:18 CEST] <furq> one of the reasons to switch was that extensions had pretty much free rein, which is a huge security nightmare
[23:22:40 CEST] <furq> so it's no surprise that it won't always be possible to create APIs to make porting possible
[23:22:41 CEST] <JEEB> yes, but basically it gives you an idea overall. it's a big change from "we don't have any API, we just let you play with our internals" to "now we define APIs, make experiments for additional capabilities"
[23:22:44 CEST] <furq> cf. vimperator
[23:22:58 CEST] <furq> there's no chance of that making a comeback
[23:23:07 CEST] <JEEB> I thought vimperator generally got through pretty well? except for one bug and not being able to work on internal pages?
[23:23:22 CEST] <JEEB> one bug being ack'd by mozilla and getting fixed, too
[23:23:33 CEST] <JEEB> see the spreadsheet I linked
[23:23:41 CEST] <furq> oh neat
[23:23:50 CEST] <furq> i thought vimium was recommended now, which is not the same at all
[23:24:33 CEST] <JEEB> it might be a different thing but bugs are actually getting ACK'd and if there are new APIs needed if you make an experiment they can get through rather quickly
[23:24:46 CEST] <JEEB> for example the show/hide tab API for tab groups
[23:25:09 CEST] <JEEB> that got an experiment and I think they're now working on actually integrating it
[23:25:26 CEST] <furq> the main thing is that they ported the dark theme from ff dev before breaking all full thirdparty themes
[23:25:39 CEST] <furq> if they'd have had a version with no dark theme i'd be long gone
[23:25:58 CEST] <furq> so i can sort of understand why people are getting so pissy about tree style tabs and stuff
[00:00:00 CEST] --- Sat Oct 28 2017