[Ffmpeg-devel-irc] ffmpeg.log.20171228

[burek]

[00:11:02 CET] <}8]> hey fellas. does anyone know if support for the mkv crop flag is on the horizon?
[02:38:57 CET] <raytiley_> google is failing me
[02:39:34 CET] <raytiley_> I'm using: ffmpeg -f lavfi -re -i testsrc=size=1280x720:rate=30 to generate some sample video.. how do I also add the sine filter so there is an audio stream available as well?
[02:42:20 CET] <c_14> -f lavfi -i sine
[02:44:14 CET] <c_14> as in, just add that as another input
[02:44:33 CET] <raytiley_> yup.. that does it :)
[02:44:44 CET] <raytiley_> was trying to figure out filter complex stuff and getting lost
[02:47:36 CET] <raytiley_> do I need to do anything special to get the correct number of samples to match the rate=30 for the video filter?
[02:48:04 CET] <c_14> "correct number of samples"?
[02:48:20 CET] <c_14> sine outputs at 48k by default afaik
[02:49:03 CET] <raytiley_> thanks
[05:41:10 CET] <newbie__> hello
[05:41:31 CET] <newbie__> could you help me?
[05:41:53 CET] <}8]> certainly..  my advice is never give up!
[05:42:02 CET] <newbie__> i have linking error, and i can't solve this problem
[05:44:47 CET] <newbie__> i wanna rtsp client reciever
[05:45:10 CET] <newbie__> so i compiled ffmpeg with this configure
[05:47:06 CET] <newbie__> PATH="$HOME/bin:$PATH" PKG_CONFIG_PATH="$HOME/ffmpeg_build/lib/pkgconfig" ./configure --prefix="$HOME/ffmpeg_build" --pkg-config-flags="--static" --extra-cflags="-I$HOME/ffmpeg_build/include" --extra-ldflags="-L$HOME/ffmpeg_build/lib" --bindir="$HOME/bin" --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffprobe --disable-ffserver --disable-avdevice --disable-devices --disable-filters --enable-network --enable-protocol=tcp
[05:50:07 CET] <}8]> rtsp_demuxer_select="http_protocol rtpdec"
[05:50:07 CET] <}8]> rtsp_muxer_select="rtp_muxer http_protocol rtp_protocol rtpenc_chain"
[05:51:37 CET] <newbie__> um...
[05:51:57 CET] <newbie__> what does it mean?
[05:52:23 CET] <}8]> check your config.log and see if what you want is enabled or disabled
[05:52:34 CET] <newbie__> PO
[05:52:36 CET] <newbie__> ok
[05:54:31 CET] <newbie__> Compiling ffmpeg works fine, but when I compile the rtsp receive example code, I get a linking error.
[05:54:56 CET] <newbie__> ffmpeg is compiled with the options I want
[05:56:14 CET] <}8]> start with the first error you see in your logs
[05:57:28 CET] <newbie__> my command is  " gcc -Wall -I/root/ffmpeg_build/include/ rtsptest.o -o rtsp_test -L/root/ffmpeg_build/lib/ /root/ffmpeg_build/lib/libavformat.a /root/ffmpeg_build/lib/libavcodec.a /root/ffmpeg_build/lib/libavutil.a -lavformat -lavcodec -lavutil -lm -lgcc -lc"
[05:57:49 CET] <newbie__> and first error is          "rtsptest.o: In function `main': rtsptest.cpp:(.text+0x19): undefined reference to `avformat_alloc_context()'"
[07:27:50 CET] <ruto> Hello. I try to work with usb camera on Windows pc. I try to get av_find_input_format("dshow");, but get null poiter as return. So, when i print all format names via av_iformat_next(p)  i not see anything,  that looks like 'dshow' what problem it is can be? 'dshow' is  wrong short name for DirectShow, or i need recompile my ffmpeg with another arguments?
[07:36:33 CET] <JEEB> ruto: you have to call the registration function first
[07:37:18 CET] <JEEB> see thr examples and search for register all in the trunk doxygen under ffmpeg.org
[07:37:32 CET] <JEEB> examples are under docs/examples
[07:37:41 CET] <JEEB> also git grep is your friend
[07:38:10 CET] <esaym153> why does this double my framerate: http://paste.debian.net/1002645/ very strange. I can for the original rate with -r 23.98, but that doesn't seem to make a difference to the file size or encode times...
[07:42:41 CET] <ruto> JEEB, i call registration functions: av_register_all();avcodec_register_all();avdevice_register_all();avfilter_register_all(); before call av_find_input_format("dshow");
[07:47:15 CET] <JEEB> ruto: then has your library been built with that component?
[07:47:41 CET] <JEEB> it should pop up in the avdevice list if it is there
[07:48:24 CET] <ruto> JEEB,  how can i request avdevice list from code?
[07:49:20 CET] <JEEB> http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavdevice/dshow.c;h=f2453e611447706daff93bbfdca42deb2fbd8301;hb=HEAD#l1313
[07:49:36 CET] <JEEB> but yes, the demuxer in avdevice is dshow
[08:03:38 CET] <ruto> JEEB, you about "G.729 raw format demuxer"?
[08:06:03 CET] <ruto> I have this line in source code of ffmpeg, but how can i get devices list from my own program? I do like in this example: http://libav-users.943685.n4.nabble.com/av-find-input-format-not-finding-formats-tp946231p946232.html and not see dshow
[08:06:51 CET] <ruto> JEEB, this is my printed formats: https://pastebin.com/xRUjr6cz
[09:53:50 CET] <diverdude> durandal_1707: This example seems to use new api: https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/decode_video.c   Is that correct?
[09:56:08 CET] <durandal_1707> yes
[10:58:23 CET] <ItWasntMe2013> does anyone have a real good solution for live conversion of frame rates? PAL -> NTSC ?  I get choppy video, specially with scrolling text.
[10:59:31 CET] <ItWasntMe2013> I found some piped solutions with mjpegtools but I don't really see any differences from the basic ffmpeg commands, any input would be appreciated
[11:09:08 CET] <AlRaquish> Hello, I'm trying a fairly simple thing and failing, is anyone willing to give me some help?
[11:09:34 CET] <AlRaquish> I want to trim two different parts of the same video, and stack them together
[11:09:58 CET] <AlRaquish> however, it seems that one of the videos is not trimmed properly, and padding is applied
[11:10:46 CET] <AlRaquish> this is the filter: split=2[f0][f1];[f0]trim=duration=10[o1];[f1]trim=start=5:duration=10[o2];[o1][o2]hstack
[11:11:30 CET] <AlRaquish> the video format is mp4, and I have applied -an to remove the audio stream
[11:15:08 CET] <AlRaquish> Of course I could do it with more than one commands, but the thing that I'm actually trying to accomplish is a bit more complex, so I would prefer if I could do it with a single command
[11:28:09 CET] <maximilian-torgg> Hello! Can anyone help me with H.265 streams produced by ffmpeg? What would be the best possiblity to stream them with the lowest latency possible to web browsers?
[11:35:35 CET] <furq> AlRaquish: you'll need to add setpts to o2
[11:38:05 CET] <AlRaquish> furq: wow thanks!
[11:45:29 CET] <ItWasntMe2013> furq: any ideas on this? a real good solution for live conversion of frame rates? PAL -> NTSC ?  I get choppy video, specially with scrolling text. I found some piped solutions with mjpegtools but I don't really see any differences from the basic ffmpeg commands, any input would be appreciated
[12:07:09 CET] <morphey> hello to all
[12:07:27 CET] <morphey> I have a problem with compilation of ffmpeg on a CentOS 6.x 64 bit (latest version)
[12:07:43 CET] <morphey> I see this script: https://gist.githubusercontent.com/wvega/132421e66bb63e452002/raw/7e131538ce997792a96981ebd24969ebe98a8cee/install-ffmpeg.sh
[12:08:05 CET] <morphey> but the problem is always the same: ERROR: opus not found using pkg-config
[12:08:15 CET] <morphey> does anyone have the same problem?
[12:35:34 CET] <furq> ItWasntMe2013: there's no particularly great way to do it
[12:36:28 CET] <furq> duplicating frames will give choppy playback, minterpolate is resource hungry and will produce artifacts, and telecine will give interlaced output which is less than ideal
[12:37:02 CET] <furq> -vf telecine=22323 is the one you want for pal to ntsc if you go down that route
[12:37:48 CET] <furq> if it's mpeg2video then you can add soft telecine flags, but not with ffmpeg and so probably not live
[12:38:13 CET] <furq> actually sorry that should be -vf telecine=pattern=22323
[12:43:55 CET] <iive> morphey: i see you build and install your own libopus. it might be good idea to check the config.log . it might be located in ffmpeg-source/ffbuild/ directory
[12:44:25 CET] <iive> also try to query libopus information manually with pkg-config to check if your path override works
[12:44:48 CET] <iive> e.g. is it an addition to the built-in paths or override.
[13:07:04 CET] <morphey> thanks @iive: I was check this, but the path is correct.
[13:07:24 CET] <morphey> I have solved the problem now, but I compile without --disable-shared
[13:07:41 CET] <morphey> I do not know why :D
[13:12:05 CET] <iive> morphey: it's possible that libopus pkconfig entry doesn't handle -static properly
[13:15:09 CET] <morphey> @iive: how can I verify this?
[13:17:23 CET] <iive> morphey:  look in config.log and see what parameters are used for pkg-config libopus query, see what you get when you run it. if it misses library paths and stuff....
[13:39:41 CET] <eyedrop-> for h264 encoding, does the preset have any effect on quality or is it strictly an encoding time/compression ratio setting?
[13:45:29 CET] <iive> eyedrop-: it controls encoder features used. It has some effect on quality but it is neglegable, if you are not bitrate constrained.
[13:48:17 CET] <eyedrop-> ok, thanks
[13:53:49 CET] <furq> eyedrop-: the same crf at a slower preset will be higher quality
[13:54:12 CET] <furq> and may or may not be smaller
[16:02:41 CET] <pgorley> hi, is nv12 the standard pixel format on osx and ios?
[16:02:58 CET] <JEEB> many hardware decoders output that
[16:03:14 CET] <JEEB> (for 4:2:0 YCbCr)
[16:03:44 CET] <pgorley> perfect, thanks!
[17:26:00 CET] <Stephen_292902> Hi, just installed ffmpeg. Want to check how exactly I can run ffmpeg in cmd (i.e. which folder do I have to be accessing the command line program from?) Thanks! Right now I'm trying the main folder but I'm getting the error 'ffmpeg is not recognizable as an internal or external command....'
[17:26:28 CET] <alexpigment> is this on windows?
[17:26:34 CET] <Stephen_292902> Yep
[17:26:37 CET] <alexpigment> type ffmpeg.exe
[17:26:41 CET] <alexpigment> instead of ffmpeg
[17:26:50 CET] <alexpigment> do ffmpeg.exe -h as a test
[17:26:57 CET] <Stephen_292902> alright, will try
[17:27:20 CET] <Fenrirthviti> That's assuming you added ffmpeg's location to your path
[17:27:29 CET] <alexpigment> true
[17:27:31 CET] <Fenrirthviti> otherwise you'll need to browse to the directory you installed it to first
[17:27:49 CET] <alexpigment> anyway, one step at a time here
[17:27:50 CET] <Stephen_292902> Still not recognized, yep
[17:28:01 CET] <alexpigment> ok, what is the location at the start of your command line?
[17:28:03 CET] <Stephen_292902> I've browsed to that directory already (it's in downloads) but it still doesn't work
[17:28:18 CET] <Fenrirthviti> What does the console output say?
[17:28:27 CET] <Stephen_292902> C:\Users\xyz\Downloads\ffmpeg-3.4.1.tar\ffmpeg-3.4.1
[17:28:33 CET] <alexpigment> ok
[17:28:36 CET] <therage3> Go to the directory where ffmpeg.exe is
[17:28:36 CET] <therage3> To do that, type "cd full-path-here"
[17:28:53 CET] <Stephen_292902> Console output is 'ffmpeg.exe' is not recognizable as an internal or external command
[17:28:55 CET] <alexpigment> tar... is that the source code you downloaded?
[17:28:56 CET] <Stephen_292902> Alright sure, thanks!
[17:29:00 CET] <therage3> hold on
[17:29:02 CET] <therage3> Why do you have a tarball
[17:29:05 CET] <Fenrirthviti> Yeah I'm not sure that's a binary
[17:29:08 CET] <Fenrirthviti> and not sure why .tar :P
[17:29:12 CET] <therage3> You need the Windows binary
[17:29:13 CET] <alexpigment> https://ffmpeg.zeranoe.com/builds/
[17:29:13 CET] <therage3> Not a tarball
[17:29:26 CET] <Stephen_292902> Ah thanks so much
[17:29:29 CET] <alexpigment> click the "download build" button
[17:29:35 CET] <Stephen_292902> Will do
[17:29:36 CET] <Stephen_292902> Couldn't find the Windows binary on the website for some reason
[17:29:46 CET] <Fenrirthviti> It's not on the ffmpeg website itself
[17:30:03 CET] <furq> 16:29:08 ( Fenrirthviti) and not sure why .tar :P
[17:30:04 CET] <Stephen_292902> Oh I see haha
[17:30:05 CET] <Fenrirthviti> that's a community hosted build, but more or less the "official" place to get it
[17:30:05 CET] <alexpigment> welcome to the world of free software ;)
[17:30:06 CET] <furq> probably winrar
[17:30:28 CET] <Stephen_292902> haha my only experience is with youtube-dl for this sort of thing
[17:30:29 CET] <alexpigment> usually the builds are on other sites for stuff like this. it's just the way it is
[17:30:30 CET] <Fenrirthviti> furq: Winrar leaves file extensions in the folder paths on extraction? Yeesh.
[17:30:35 CET] <Stephen_292902> And I think the official site provided the binary then
[17:30:52 CET] <furq> no, it stripped off the .gz
[17:30:59 CET] <furq> it just doesn't recognise .tar.gz as one extension
[17:31:08 CET] <furq> or xz or whatever
[17:31:08 CET] <alexpigment> makes sense
[17:31:14 CET] <Fenrirthviti> ahh, gotcha.
[17:31:22 CET] <Stephen_292902> oh I see haha
[17:31:34 CET] <Stephen_292902> Works now by the way, thanks so much!
[17:32:09 CET] <alexpigment> cool, good luck!
[17:32:17 CET] <Stephen_292902> thank you :)
[17:41:04 CET] <broman> can someone please help me? I have several video files (and they keep coming) and I need to stream them with ffmpeg... I already do that, but as I hop from one file to the other, there's a delay on my rtmp server...
[18:03:03 CET] <spacerabbit> sounds normal
[18:03:14 CET] <spacerabbit> whats the software?
[19:45:30 CET] <nostrora> Hello, ID3 is the standard for metadata in audio music file ?
[19:47:54 CET] <pgorley> nostrora: it's a de facto standard in mp3 files, not sure if it's widely used anywhere else
[19:48:33 CET] <nostrora> pgorley: i create flac file, what i have to use for it ? ID3 is good ? or i need to use other ?
[19:48:58 CET] <c_14> flac usually uses ogg tags afair
[19:49:43 CET] <pgorley> most flac decoders don't know how to parse id3, some skip them out of convenience
[19:49:58 CET] <pgorley> s/most/some
[19:51:32 CET] <pgorley> flac uses the same tagging system as vorbis (vorbis comments)
[19:52:01 CET] <nostrora> pgorley: vorbis comments == ogg targs ?
[19:52:29 CET] <pgorley> yea
[20:07:29 CET] <nostrora> If a convert a file from FlAC to MP3 with ffmpeg. ffmpeg will convert ogg comment to id3 ?
[20:09:28 CET] <pgorley> no clue
[20:09:38 CET] <pgorley> try it out and come back to us on that ;)
[20:11:19 CET] <dinkan> Hi all
[20:11:33 CET] <dinkan> I am essentially trying to do is to replicate ./ffmpeg -re -i TEST_VIDEO.ts -acodec copy -vcodec copy -f rtp_mpegts rtp://239.245.0.2:5002
[20:11:44 CET] <dinkan> Streaming is happening, but the quality is terrible. Looks like many frames are skipped plus streaming is happening really slow(buffer underflow reported by VLC player)
[20:11:56 CET] <dinkan> File plays perfectly fine directly on VLC player.
[20:12:12 CET] <dinkan> Stream details are here - https://pastebin.com/1a0fJny7
[20:12:36 CET] <dinkan> And my slightly modified source is here - https://pastebin.com/gumpBpG8
[20:12:47 CET] <nostrora> Yes it can with -map_metadata 0 -id3v2_version 3 :)
[20:13:04 CET] <dinkan> Could someone please guide me as to where I'm doing it wrong?
[20:13:15 CET] <dinkan> Or something that can improve the performance?
[20:13:23 CET] <dinkan> Thank you in advance.
[20:24:18 CET] <diverdude> durandal_1707: hi, i am trying to understand why i am getting segfault when running the demuxing_decoding.c. I found out that my problem occurs in this line: https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/demuxing_decoding.c#L167 because st->codecpar has value 0x0. However i do not understand why st->codecpar is NULL. What could be the reason for this?
[20:25:33 CET] <durandal_1707> diverdude: build it via makefile
[20:26:58 CET] <alexpigment> dinkan: i don't know exactly what's going on, but out of curiosity, are you trying to stream this to client via a web browser? if so, 1080i anamorphic is probably not your format. you ideally want to be streaming 1080p or lower
[20:27:22 CET] <diverdude> durandal_1707: but i built it like this: gcc demuxing_decoding.c -o test_demux -I ./ffmpeg-20171223-d02289c-macos64-dev/include/ -L ./ffmpeg-20171223-d02289c-macos64-shared/bin/ -lavcodec -lavdevice -lavfilter -lavformat -lavutil -lpostproc -lswresample -lswscale
[20:27:28 CET] <diverdude> durandal_1707: why is that wrong?
[20:28:23 CET] <durandal_1707> dunno
[20:31:03 CET] <diverdude> alexpigment: do you have a moment to help me out?
[20:31:18 CET] <alexpigment> if it's above what you've written above, i have no clue
[20:31:59 CET] <caraya> I'm trying to add subtitles using ffmpeg using this command https://pastebin.com/pnbJfGHe but it's not honoring the styling of the caption file. I'm not certain if I'm writing the command correctly or is this a bug?
[20:33:39 CET] <furq> caraya: i don't see anything to do with subs in that command
[20:33:57 CET] <furq> also there's really no point using x265 with those params
[20:34:03 CET] <furq> it'll be slower and less efficient than x264
[20:34:29 CET] <furq> and less compatible obv
[20:34:36 CET] <alexpigment> furq: they put in -c:s mov_text fwiw
[20:34:45 CET] <furq> oh
[20:34:57 CET] <caraya> @furq what's the syntax I should use for ass subs? This is my first time tyring to add the subs
[20:35:01 CET] <furq> well yeah mov_text is plaintext, it has no styling at all
[20:35:06 CET] <alexpigment> i have zero experience with messing with subtitles, so that's all i can say on it. but there is at least that in the command
[20:35:25 CET] <furq> you'd need to use mkv and ass or burn the subs in if you want to keep the styling
[20:36:09 CET] <caraya> will look into that... thanks
[20:36:23 CET] <furq> i mean i assume that's what you already have
[20:36:27 CET] <furq> so maybe just don't reencode
[20:36:44 CET] <alexpigment> yeah, let's get to the bottom of this need to re-encode :)
[20:37:06 CET] <alexpigment> is it because the original is just too good of quality? ;)
[20:37:29 CET] <caraya> it's a file size issue for personal use, not worried about compatibility too much...
[20:37:49 CET] <alexpigment> what's the current bitrate of the file, out of curiosity?
[20:37:57 CET] <furq> well yeah x265 with those settings is unlikely to compress better
[20:38:18 CET] <furq> you don't see any gains at all over x264 until you start using the slower presets
[20:43:06 CET] <caraya> alexpigment, the original is 1844kb
[20:43:25 CET] <alexpigment> hmmm, i don't see why you'd want to squeeze it down further, personally
[20:43:38 CET] <alexpigment> save your time, buy a hard drive
[20:43:51 CET] <alexpigment> preserve history; don't destroy it
[20:44:24 CET] <alexpigment> anyway, just my opinion on it. others are probably happy to help you do what you're wanting
[20:45:33 CET] <caraya> I'm thinking about leaving it as is... I'm still trying to figure out the syntax for adding .ass subs even if I decide not to do it for this particular project
[20:47:01 CET] <alexpigment> in an mp4?
[20:47:17 CET] <alexpigment> or keeping it in an MKV
[20:48:15 CET] <caraya> in an mp4 if possible, mkv if I have to
[20:48:21 CET] <alexpigment> mkv supports ass
[20:48:23 CET] <alexpigment> mp4 doesn't
[20:48:26 CET] <alexpigment> https://en.wikibooks.org/wiki/FFMPEG_An_Intermediate_Guide/subtitle_options
[20:48:32 CET] <furq> ^
[20:48:36 CET] <furq> if you want to hardsub then -vf subtitles
[20:48:41 CET] <furq> !filter subtitles @caraya
[20:48:41 CET] <nfobot> caraya: http://ffmpeg.org/ffmpeg-filters.html#subtitles-1
[20:48:42 CET] <alexpigment> so, if you have an MKV with ass subs right now, then just *play the video*
[20:48:53 CET] <caraya> ok, that would answer the question
[20:48:53 CET] <furq> and if you want to softsub then you need a container that supports your subtitle format
[20:48:56 CET] <furq> which is probably mkv
[20:49:02 CET] <caraya> thanks
[20:51:09 CET] <alexpigment> man, there are a lot of people who just want to waste their own time re-encoding things for little to no benefit (and a lot of detriment). i guess i'm out of touch with the kids
[20:52:07 CET] <alexpigment> it's like "oh, i'm going go through and convert my old xvid files all to h.264", and then two years later it's like "oh i'm going to go through and convert my old h.264 files to h.265", etc
[20:52:37 CET] <alexpigment> for me it's like "oh, my player supports xvid? cool. done."
[21:00:17 CET] <TychoWerner> Goodday, I am trying to encode a live mp3 stream to AAC that has to be accessable via the browser, I can't find the answer to my questions online, who could help me?
[21:05:05 CET] <DHE> you haven't asked a question, so start there
[21:06:03 CET] <TychoWerner> @DHE what do you mean?
[21:06:56 CET] <DHE> "who can help me" is not the way you start these things. not knowing what the problem is, nobody knows if they can help you. so start by asking your question.
[21:15:56 CET] <diverdude> when i do ./configure --list-demuxers i get a looooong list of demuxers, like rv10, rv20, vcr1, .... etc. I thought a demux was just a way to split a container into seperate streams eg. audio, video and subtitles....what are all these different types of mux?
[21:19:10 CET] <kepstin> diverdude: those are all different types of containers (or in a few cases raw media types) that ffmpeg can demux
[21:20:53 CET] <kepstin> and yes, there's a lot of them.
[21:32:47 CET] <diverdude> kepstin: ah ok i see
[21:33:24 CET] <diverdude> kepstin: so if i want to understand what containers are supported in ffmpeg i look at which mux/demux are available?
[21:34:05 CET] <kepstin> diverdude: yeah. If you have a built ffmpeg, run "ffmpeg -formats" to get an list with some capabilities and descriptions.
[21:36:01 CET] <diverdude> kepstin: ok i see...also, i see in the ./configure a flag: "enable full grayscale support". If i do not enable this, does that then mean that grayscale is not supported?
[21:45:50 CET] <diverdude> durandal_170: I see in the ./configure a flag: "enable full grayscale support". If i do not enable this, does that then mean that grayscale is not supported?
[21:47:23 CET] <durandal_170> diverdude: i dunno what that option does
[22:40:50 CET] <diverdude> hi, when i compile ffmep i run the following configure: ./configure --enable-shared --logfile=/Users/foobar/Downloads/ffmpegbuild/ffmpeg_install/logfile --prefix=/Users/foobar/Downloads/ffmpegbuild/ffmpeg_install --shlibdir=/Users/foobar/Downloads/ffmpegbuild/ffmpeg_install/shared --arch=x86_64     and following make and make install which seems to work great.
[22:41:03 CET] <diverdude> However when i then want to compile my ffmpeg program i am getting:  ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)
[22:41:44 CET] <diverdude> Why are there no symbols for x86_64 when i supplied --arch=x86_64 to configure when building?
[22:46:57 CET] <alexpigment> diverdude: https://stackoverflow.com/questions/31510535/symbols-not-found-for-architecture-x86-64-on-mac-when-using-qtopencvffmpeg
[23:04:43 CET] <Tachyon> Hi guys, I have mpegts stream which containts yuyv422 video. When the raw data is exported to a file, I can play it using "ffplay -f rawvideo -pixel_format yuyv422 -video_size 640x480 -framerate 30 file". How can I tell ffmpeg/ffplay that the mpegts stream contints video with these params?
[23:06:44 CET] <Tachyon> when I try to play the file it fails because it sees the data in the mpegts stream as binry data (it obviously doesn't contain any headers) so it can't determine how to play it
[23:15:00 CET] <BtbN> There is raw unencoded video in your mpegts?
[23:15:21 CET] <Tachyon> yup
[23:15:42 CET] <Tachyon> BtbN: it is just mpegts packed stream from webcam
[23:15:46 CET] <Tachyon> raw
[23:15:53 CET] <BtbN> that's super weird
[23:15:57 CET] <BtbN> how do you get the data out of there?
[23:16:16 CET] <Tachyon> i got it out of there using this: https://stackoverflow.com/questions/30704366/extract-bytes-of-specific-stream-from-mpegts-file-using-ffmpeg
[23:16:21 CET] <Tachyon> ffmpeg -i video.ts -map 0:1 -codec copy -f data stream.txt
[23:16:50 CET] <BtbN> I doubt you'll be able to do that in one step then
[23:16:52 CET] <Tachyon> after that, I can play the stream.txt using the ffplay -f rawvideo -pixel_format yuyv422 -video_size 640x480 -framerate 30
[23:17:02 CET] <BtbN> But you might be able to use two ffmpeg instances piping into each other
[23:17:14 CET] <Tachyon> that is the last resort I'm trying to avoid :)
[23:17:27 CET] <BtbN> mpegts does not even support raw video officially
[23:17:30 CET] <BtbN> I think
[23:17:46 CET] <alexpigment> i've never seen an mpegts with raw
[23:17:54 CET] <alexpigment> fwiw
[23:18:05 CET] <Tachyon> i though mpegts is just a protocol that breaks some continuous data into chunks not caring about what the chunks are
[23:18:36 CET] <Tachyon> but I know little about it :)
[23:18:53 CET] <alexpigment> Tachyon: well, i can tell you that ffmpeg's tsmuxer is not that forgiving. if you try to include Blu-ray PCM, it's just like "oh sorry"
[23:19:12 CET] <Tachyon> :<
[23:19:31 CET] <Tachyon> it does work with -codec copy
[23:19:34 CET] <alexpigment> anecdotal, i know, but that maybe gives you an idea of how janky the mpegts is in ffmpeg
[23:20:30 CET] <Tachyon> ok, so to be exact, what I was trying to do:
[23:20:37 CET] <Tachyon> I want no latency video stream from webcam
[23:20:56 CET] <Tachyon> so my idea was, to send raw yuyv422 dat through mpegts
[23:21:13 CET] <Tachyon> hoping that the decoding would be fast
[23:21:35 CET] <Tachyon> when I used the mpeg2video or what is it called there was like 1-2sec delay
[23:21:38 CET] <Tachyon> so I used this
[23:21:39 CET] <Tachyon> ffmpeg -f dshow -framerate 30 -video_size 640x480 -i video="BisonCam, NB Pro" -f mpegts -vcodec copy - | ffplay
[23:21:59 CET] <alexpigment> do you have a hardware encoder available on your system by chance?
[23:22:02 CET] <Tachyon> and obviously ffplay can't play it because it doesn't know what the mpegts containts
[23:22:15 CET] <Tachyon> nope, don't think so
[23:22:33 CET] <alexpigment> nvidia, intel, amd, etc?
[23:23:13 CET] <Tachyon> nvidia
[23:23:19 CET] <alexpigment> what model?
[23:23:22 CET] <Tachyon> i tried the hwaccel
[23:23:27 CET] <Tachyon> but it said my model is too old
[23:23:27 CET] <Tachyon> :(
[23:24:08 CET] <Tachyon> -c:v h264_nvenc didn't work
[23:24:21 CET] <furq> Tachyon: use nut?
[23:24:29 CET] <furq> -f nut
[23:25:27 CET] <Tachyon> furq: never heard of, will look at it
[23:29:11 CET] <Tachyon> furq: wow, much much better, thanks!
[23:30:05 CET] <Tachyon> if anyone is interested, the end result, which has almost 0 latency is:
[23:30:06 CET] <Tachyon> ffmpeg -f dshow -framerate 30 -video_size 640x480 -i video="BisonCam, NB Pro" -f nut -codec copy - | ffplay -probesize 32 -sync ext -
[23:31:41 CET] <Tachyon> oh, guys, you are simply the best, thank you a lot!
[00:00:00 CET] --- Fri Dec 29 2017