[Ffmpeg-devel-irc] ffmpeg.log.20200115

Thu Jan 16 03:05:02 EET 2020

[00:11:37 CET] <tomb^> thank you!
[01:18:26 CET] <KodiakIT> So, cehoyos, like I said, searching the manpage for ocr/OCR & optical just return "pattern not found", and you mentioned something about compiling it in?
[01:19:00 CET] <cehoyos> (where exactly did you search?)
[01:19:14 CET] <cehoyos> https://ffmpeg.org/ffmpeg-filters.html#ocr
[01:19:16 CET] <KodiakIT> man ffmpeg from console
[01:19:21 CET] <KodiakIT> oh
[01:19:38 CET] <cehoyos> I may misremember but I don't think man ffmpeg is very useful
[01:19:43 CET] <cehoyos> There is ffmpeg -h full
[01:19:50 CET] <cehoyos> and ffmpeg -h filter=ocr (not tested)
[01:20:01 CET] <nicolas17> there's more manpages
[01:20:07 CET] <cehoyos> ok
[01:20:14 CET] <nicolas17> like "man ffmpeg-filters"
[01:20:57 CET] <KodiakIT> nicolas17, didn't notice that, I see that in my tab-complete now.
[01:21:43 CET] <nicolas17> and ffmpeg-all for the full 140000 words of documentation :)
[01:52:20 CET] <melatonina> Hello. Is this channel also for programming against libavcodec and friends?
[01:53:14 CET] <relaxed> melatonina: yes
[01:53:17 CET] <melatonina> Ok. #ffmpeg-devel topic says it is
[01:53:21 CET] <melatonina> relaxed: thankx
[02:02:19 CET] <melatonina> I'm trying to setup a transcoding. When I open the encoder, I get the "The encoder timebase is not set." Following some StackOverflow answer, I set the output stream sample rate copying it from the input stream (line 53 in the linked gist). It doesn't work. Additionally, the sample rate is 0/0. How should I set the timebase? https://gist.github.com/mel4tonin4/0d17d202fca32de42671fb4a5c2c5ea4
[02:03:27 CET] <DHE> there's actually a time_base field at AVFormatContext->streams[i]->time_base iirc
[02:04:07 CET] <DHE> if you can get away with it, set it to 1/(samplerate) so that the pts value is identical to the number of samples send to far
[02:09:06 CET] <melatonina> DHE: trying that. Thanks
[02:13:33 CET] <melatonina> DHE: just for checking, I set outputStream.r_frame_rate(AVRational().num(44100).den(1))
[02:13:34 CET] <melatonina>     outputStream.time_base(AVRational().num(1).den(44100)) but I'm still getting the same message
[02:16:05 CET] <melatonina> Ok, the codec has no timebase() but codec context does. I set it there and the messages went away
[07:54:48 CET] <st0n3c0ld> hello
[07:55:02 CET] <st0n3c0ld> I can't record my screen. it is always like this : it records the cached screen. not real screen it records windows that aren't there any more. if I record 20 screencasts all of them sho the first recording that i made.
[07:55:04 CET] <st0n3c0ld> why?
[07:55:56 CET] <st0n3c0ld> Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller
[08:56:12 CET] <st0n3c0ld> why it is like this?
[08:56:13 CET] <st0n3c0ld> it is my screen record https://filebin.net/d5jsf0jqauiv1yqq
[08:56:29 CET] <st0n3c0ld> look at the time
[12:43:31 CET] <mlok> gcc is unable to create an executable file.
[12:43:40 CET] <mlok> C compiler test failed.
[12:43:51 CET] <mlok> What would be the first place to look? :)
[12:44:04 CET] <DHE> the config.log file (possibly inside the ffbuild directory depending on your ffmpeg version)
[12:44:30 CET] <mlok> Thanks, I am using a custom compiler
[12:44:49 CET] <mlok> for ARM architecture
[12:45:09 CET] <DHE> oh a cross compiler... well then...
[12:45:13 CET] <mlok> DHE: yeah
[15:22:54 CET] <alazare619> i need a ffmpeg cli string to copy every audio and video container to a mkv
[15:23:33 CET] <alazare619> would that be , map - 0 -c Copy ?
[15:24:24 CET] <alazare619> or -c Copy
[15:24:28 CET] <alazare619> with no map?
[16:12:38 CET] <StephenLynx> hey, I'm trying to make png thumbs out of videos with libavformat. but the remuxing example doesn't work even for videos here.
[16:12:40 CET] <StephenLynx> https://ffmpeg.org/doxygen/trunk/remuxing_8c-example.html
[16:12:42 CET] <StephenLynx> any pointer?
[16:13:06 CET] <StephenLynx> the resulting file seems corrupt and when remuxing to the same format, webm, the file is about 90% smaller
[16:16:32 CET] <JEEB> lol, thumbnail making. i think one of the first things i tested api usage with back in ye olde 2013
[16:17:36 CET] <JEEB> https://github.com/jeeb/matroska_thumbnails/tree/master/src
[16:17:57 CET] <JEEB> really old code and uses old apis but might or might not be useful
[16:49:10 CET] <StephenLynx> anything else.
[16:49:12 CET] <StephenLynx> helps*
[18:50:20 CET] <waleee-cl> is it possible to use another video file as a 'template' for conversions settings? (ie without manually checking it with ffprobe)
[20:10:40 CET] <StephenLynx> JEEB, got stumped on IStream
[20:10:48 CET] <StephenLynx> :\
[20:10:51 CET] <JEEB> that's windows specific thing :P
[20:10:54 CET] <StephenLynx> fml
[20:11:03 CET] <JEEB> I just implemented an AVIO wrapper around windows's IO mechanism
[20:11:16 CET] <JEEB> which it uses for explorer out of process plugins
[20:24:05 CET] <StephenLynx> I assume BITMAPINFO is another windows specific feature, JEEB ?
[20:25:09 CET] <JEEB> also I skipped using libavfilter for scaling/colorspace conversions etc
[21:35:06 CET] <vlt> waleee-cl: I asked a veeery similar question here a few days ago. The concensus seemed to be no because with most video codecs not all the parameters used to encode are stored in the final stream.
[22:59:44 CET] <fatturtle> Hi. I'm trying to transcode flac to opus while preserving the cover art, but I get errors. This is the command I am using 'ffmpeg -i input.flac -map 0:0 -map 0:1 -c:a libopus -c:v copy out2.opus'
[23:33:24 CET] <BtbN> What even is .opus? Does it support cover art, or is it an mp3 like raw stream dump?
[23:35:27 CET] <relaxed> ogg
[23:36:14 CET] <pink_mist> "but I get errors" he says
[23:36:21 CET] <pink_mist> and then doesn't even show us the output
[23:36:34 CET] <kepstin> opus is ogg opus, it uses a similar tag format to ogg vorbis
[23:36:50 CET] <relaxed> I don't think ffmpeg's opus muxer supports covert art
[23:37:17 CET] <kepstin> cover art in ogg vorbis/opus is kind of a hack iirc, since they don't really do binary tags? IIRC some apps store the image base64 encoded in a text tag
[23:38:03 CET] <kepstin> (i think they might actually use a base64 encoded *flac image frame* in the vorbis comment or something ridiculous like that?)
[23:38:35 CET] <furq> https://trac.ffmpeg.org/ticket/4448
[23:40:54 CET] <kepstin> ah, my terminology is wrong, it's a "flac picture block" :)
[23:41:03 CET] <furq> looks like 4442 got fixed so the code is already there
[23:41:25 CET] <furq> and the m4a muxer already has some workaround for the video stream/cover art ambiguity
[23:57:18 CET] <fatturtle> Here is the ffmpeg output https://pastebin.com/evDxwEEi
[23:58:19 CET] <fatturtle> I'm not really sure how you get cover art on opus, but I do know it can be done. I was able to do it using some other tagging software (kid3).
[00:00:00 CET] --- Thu Jan 16 2020