[Ffmpeg-devel-irc] ffmpeg.log.20190918

[burek]

[03:28:32 CEST] <nicolas17> can I speed up a video introducing motion blur instead of dropping frames entirely?
[03:32:28 CEST] <cards> not by very much
[03:32:49 CEST] <cards> blend 2 frames togther if you want motion blur, not 60
[03:38:53 CEST] <nicolas17> I mean how do I do it with ffmpeg?
[07:22:18 CEST] <C0nundrum> hello
[07:22:44 CEST] <C0nundrum> When using ddshow as an input, anyone know how to set camera settings like exposure and gain ?
[09:54:00 CEST] <ricemuffinball> what soundcard do people recommend for using with ffmpeg?
[11:08:16 CEST] <snooky> moin
[11:08:58 CEST] <JEEB> ricemuffinball: I think that often depends on what OS you're using etc
[11:09:18 CEST] <JEEB> since more than FFmpeg itself, it's usually the audio input APIs and the driver support that drive issues
[11:09:33 CEST] <ricemuffinball> i use windows
[11:10:21 CEST] <JEEB> and thus most likely directshow or so as input? unfortunately I have no experience of that :)
[12:31:16 CEST] <pk08> i want to add a global variable which can access in libavformat/mpegts.c and libavfilter/vf_drawtext.c
[12:31:16 CEST] <pk08> so for that, i created a header file called "test.h" and defined a variable with extern int anyError; and then included test.h file in both above .c files
[12:31:16 CEST] <pk08> and i redefined that variable in mpegts.c like int anyError = 0;
[12:31:16 CEST] <pk08> now when i try to compile ffmpeg, i am getting libavfilter/libavfilter.so: undefined reference to `anyError'
[12:31:16 CEST] <pk08> i tried to build static build but getting same error there too!
[12:31:56 CEST] <BtbN> Global variables are bad. Don't use them, ever.
[12:32:32 CEST] <BtbN> Those two source files are in separate libraries as well, so they can't just share a global variable like that anyway.
[12:32:45 CEST] <pk08> so what should i do to fix my issue?
[12:32:51 CEST] <BtbN> Fix what issue?
[12:33:03 CEST] <pk08> to get access for a variable
[12:33:23 CEST] <BtbN> You just don't?
[12:33:31 CEST] <pk08> i tried to use getter/setter mathod too
[12:33:35 CEST] <pk08> but it ddidnt work
[12:33:55 CEST] <BtbN> It's be much better to state your actual problem instead of asking how to implement how you think to solve it.
[12:33:57 CEST] <pk08> BtbN: so cant access at all?!
[12:34:13 CEST] <BtbN> Global variables are a design flaw. So yes, you just don't.
[12:34:35 CEST] <pk08> ok, so i want to make a error cc error counter from mpegts.c
[12:34:59 CEST] <pk08> and i want to dispaly total cc errors on screen, using showtext filter
[12:35:14 CEST] <pk08> so i want to access that error counter in libavfilter
[12:35:29 CEST] <BtbN> You could add the error count as side data to the frames.
[12:35:51 CEST] <pk08> ok, so how can i do that?
[12:35:57 CEST] <BtbN> By using the side data API
[12:35:59 CEST] <pk08> can you please explain a bit more?
[12:36:20 CEST] <BtbN> No, I'd have to look it up for that, and you can as well do that yourself.
[12:37:15 CEST] <pk08> ok, thanks for your help
[12:38:03 CEST] <BtbN> It should be pretty easy to find the respective APIs for side data.
[13:00:39 CEST] <^Neo> Good morning friends! Does anyone know of a work around for this issue? https://trac.ffmpeg.org/ticket/1102
[13:03:09 CEST] <JEEB> yes, the J2K and HEVC decoders output fields separately in case of field coding, feel free to add the filter that sticks two images together
[13:03:13 CEST] <JEEB> I don't remember its name :P
[13:07:42 CEST] <durandal_1707> weave
[13:07:51 CEST] <JEEB> thank you
[13:09:36 CEST] <^Neo> weave tinterlace?
[13:10:43 CEST] <durandal_1707> weave filter is simpler
[13:43:58 CEST] <th3_v0ice> Is it possible to set number of threads in the API that a filter is using?
[13:49:54 CEST] <durandal_1707> th3_v0ice: yes, via filtergraph
[13:50:10 CEST] <durandal_1707> or as filter option for each filter
[13:53:15 CEST] <th3_v0ice> durandal_1707: Can you provide some basic example? Thanks
[13:55:37 CEST] <durandal_1707> th3_v0ice: look at documentation
[13:58:31 CEST] <th3_v0ice> durandal_1707: I can only find ffmpeg-filters online, and only filter with threads is libvmaf. I am surely not looking at the correct place.
[13:59:18 CEST] <durandal_1707> threads=X as extra option for every filter, additionally there is threads to be set for whole filtergraph
[14:00:53 CEST] <th3_v0ice> So I can just "threads=2" in the avfilter_graph_create_filter() args parameter?
[14:01:55 CEST] <durandal_1707> no, per each filter option
[14:02:06 CEST] <durandal_1707> or as avfiltergraph AVOption
[14:03:03 CEST] <th3_v0ice> I am sorry but I am not following you
[14:03:53 CEST] <durandal_1707> -vf filter=threads=X:optionZ=Y
[14:04:24 CEST] <durandal_1707> for  global filtergraph you need to find it on your own
[14:04:48 CEST] <th3_v0ice> Oh, like that! Where can I find the documentation for global filtergraph?
[14:06:12 CEST] <th3_v0ice> Is it as simple as filter_graph->nb_threads = 3;?
[15:30:22 CEST] <th3_v0ice> durandal_1707: Thanks, this did the trick.
[19:17:54 CEST] <Sirisian|Work> I'm having an issue using --enable-decklink. ffmpeg compiles fine, but when I add --enable-decklink and --extra-cflags='-I/c/DeckLinkSDK/Win/include' (I already ran midl on the idl file and it output the DeckLinkAPI.h) it says "ERROR: DeckLinkAPI.h not found". In the mingw terminal running ls -l /c/DeckLinkSDK/Win/include clearly shows "DeckLinkAPI.h". I tried copying it into one of the other include directories and I get the
[19:17:55 CEST] <Sirisian|Work> same result.
[19:23:56 CEST] <Sirisian|Work> oh wait, looking at the config.log I think it's throwing that but it's not actually the error. As in another error is causing that to be incorrectly displayed.
[19:41:36 CEST] <Sirisian|Work> ah I'm using mingw 32-bit headers somehow instead of the 64 ones. Neat.
[20:08:08 CEST] <SimAV> Hi, I've got a problem with audio/video sync (in chrome based browsers, but not in Firefox) when passing a mkv livestream via ffmpeg through icecast and letting a second ffmpeg remux the video to dash
[20:08:20 CEST] <SimAV> When replacing icecast by a pipe between the two ffmpeg's (the first encoding different bitrates/resolutions and packing them into a matroska container -- the second remuxing the matroska input to dash), audio and video is in sync.
[20:09:05 CEST] <SimAV> When asking in #icecast I got the following replies: """
[20:09:07 CEST] <SimAV> There is no code in icecast that rewrites the timestamps.
[20:09:13 CEST] <SimAV> I would guess it's a kind of ffmpeg bug.
[20:09:25 CEST] <SimAV> maybe it does not use the timestamps to sync the clusters but considers both tracks to be sync and then reads them as they are.
[20:09:25 CEST] <SimAV> """
[23:04:03 CEST] <Sirisian|Work> https://trac.ffmpeg.org/wiki/CompilationGuide <-- this mentioned a "--cpu" flag, but there's no documentation about it? Does it have a list of valid values?
[23:09:35 CEST] <JEEB> Sirisian|Work: seems like it mostly checks it against some sort of string template
[23:10:00 CEST] <JEEB> so there's no exact list
[23:10:16 CEST] <kepstin> Sirisian|Work: in theory it accepts anything your compiler takes with the -march or -mcpu option
[23:10:24 CEST] <kepstin> Sirisian|Work: but there's a hardcoded list on x86
[23:11:13 CEST] <kepstin> well, some patterns, it's not completely hardcoded
[23:12:02 CEST] <kepstin> https://git.ffmpeg.org/gitweb/ffmpeg.git/blob/HEAD:/configure#l5104
[23:19:56 CEST] <Sirisian|Work> ah, I'll look more into it. Thanks. I'm building chromium's ffmpeg for 64-bit using clang-cl on windows. Seeing a number of unknown 'cpu' type 'amdnop'. It's referencing libavcodec/x86 though in the logs, so perhaps I missed something elsewhere.
[00:00:00 CEST] --- Thu Sep 19 2019