[Ffmpeg-devel-irc] ffmpeg.log.20180930

burek burek021 at gmail.com
Mon Oct 1 03:05:02 EEST 2018


[00:40:01 CEST] <Hello71> keglevich: do you have enough swap
[00:54:54 CEST] <furq> why would that matter if he's not running out of memory
[01:54:49 CEST] <rkantos_> can someone give me either a nice one liner or a path to the right direction for either making or playing back a video as 1920x1200 (for example) when each of the frames are 2x1920 (Horizontal x Vertical )? I'm trying to make a fast preview of a line scan capture.. (diy finish line camera)
[02:09:08 CEST] <Hello71> furq: windows doesn't have overcommit
[02:10:20 CEST] <JEEB> also since it didn't seem like it actually crashed it would make sense to actually check where that allocation was and for what value
[02:14:33 CEST] <furq> does the dts decoder support dts-hd ma nowadays
[02:15:29 CEST] <furq> yes it does, nvm
[02:16:47 CEST] <JEEB> yup
[02:16:57 CEST] <JEEB> the dcadec guy merged his work into FFmpeg
[02:17:00 CEST] <JEEB> and everyone was happy
[04:13:57 CEST] <jiffe> is there a way to extract a set of chapters from an mkv into another mkv?
[04:15:04 CEST] <furq> -map_chapters
[04:15:06 CEST] <furq> or use mkvmerge
[04:19:50 CEST] <jiffe> gotcha
[05:26:43 CEST] <unomystEz> I'm trying to cross compile for arm64 but I'm getting a "aarch64-none-elf-gcc is unable to create an executable file" error, any ideas?
[05:28:23 CEST] <tdr> thats not a valid chost type,your cross env setup is wrong
[05:28:54 CEST] <unomystEz> chost?
[05:30:52 CEST] <unomystEz> https://paste.pound-python.org/show/zaGXLy0Yy2LViwyPMXbP/
[05:30:55 CEST] <unomystEz> that's the command line I'm using
[05:32:37 CEST] <tdr> i dont know what dev kit you're using, maybe that's how they name their gcc.
[05:33:14 CEST] <tdr> you should probable echo $CFLAGS tho
[05:33:35 CEST] <unomystEz> tdr: this is devkitpro, I'm trying to port ffmpeg to the nintendo switch
[05:33:46 CEST] <unomystEz> https://github.com/devkitPro/pacman-packages/blob/master/switch/flac/PKGBUILD
[05:33:51 CEST] <unomystEz> that's an example of a port for flac
[05:34:06 CEST] <tdr> you're doing thi: CFLAGS="${CFLAGS}"   .. so if CFLAGS is set weird or with -02 vs -O2 gcc is going to fail tests
[05:34:31 CEST] <unomystEz> my CFLAGS are "-O2 -ffunction-sections -fdata-sections -march=armv8-a -mtune=cortex-a57 -mtp=soft -fPIC -ftls-model=local-exec"
[05:34:59 CEST] <tdr> look at the configure log, see what test it failed
[05:35:21 CEST] <unomystEz> ok
[05:35:37 CEST] <unomystEz> sorry for ignorance, but where is the configure log?
[05:37:07 CEST] <tdr> it should be in your build directory (unless its being redirected).   config.log
[05:37:38 CEST] <unomystEz> found it
[05:38:24 CEST] <unomystEz> ok it must not be running the right gcc
[05:38:37 CEST] <unomystEz> considering it thinks: gcc: error: unrecognized command line option '-mtp=soft'
[05:38:49 CEST] <tdr> makes it easy to find right?
[05:39:10 CEST] <unomystEz> yeah this is great
[05:39:13 CEST] <unomystEz> thank you for your help
[05:39:17 CEST] <unomystEz> I should be able to manage from here
[05:39:20 CEST] <tdr> no problem, good luck
[05:41:36 CEST] <unomystEz> it's compiling now (fingers crossed)
[05:55:41 CEST] <unomystEz> success
[05:55:45 CEST] <unomystEz> thanks again tdr
[05:57:48 CEST] <tdr> good job
[06:48:29 CEST] <unomystEz> tdr: have linking errors when trying to build against ffmpeg
[06:48:40 CEST] <unomystEz> i.e, undefined reference to `avcodec_close'
[06:48:53 CEST] <unomystEz> using $(/opt/devkitpro/portlibs/switch/bin/aarch64-none-elf-pkg-config --cflags --libs libavformat libavcodec libswresample libswscale libavutil)
[06:49:11 CEST] <tdr> it prob cannot find your header files
[06:49:28 CEST] <unomystEz> but this is at the linker phase?
[06:54:41 CEST] <unomystEz> perhaps it's an issue with the linking order?
[06:55:01 CEST] <tdr> you're still compiling ffmpeg?
[06:55:56 CEST] <unomystEz> it's compiled and installed
[06:56:00 CEST] <unomystEz> I'm trying to link my program against it
[06:56:04 CEST] <unomystEz> it compiles just won't link
[06:56:17 CEST] <tdr> your program needs to know where the ffmpeg headers sit
[06:56:25 CEST] <unomystEz> I assume it does since it compiles
[06:56:35 CEST] <unomystEz> this is a linker issue
[06:56:38 CEST] <tdr> it uses those, it wont even touch the libs that it compiled unless you're doing some static thing
[06:56:50 CEST] <unomystEz> I am compiling statically
[06:57:43 CEST] <tdr> lovely
[06:58:02 CEST] <unomystEz> =)
[06:59:25 CEST] <unomystEz> perhaps --pkg-config-flags="--static" might help
[07:00:05 CEST] <tdr> maybe, did you check if your ffmpeg installked pc files for it?
[07:00:13 CEST] <unomystEz> it did
[07:00:36 CEST] <unomystEz> -I/opt/devkitpro/portlibs/switch/include -L/opt/devkitpro/portlibs/switch/lib -lavformat -lm -lbz2 -lz -lavcodec -lm -lz -lswresample -lm -lswscale -lm -lavutil -lm
[14:11:28 CEST] <trfl> FFmpeg appears to make several additional calls to the avio read_packet callback after it has returned AVERROR_EOF. The number of additional calls appear to depend on some internal state. Is this intended behavior or a bug? see https://ocv.me/dev/?repro/avio_remuxing.c  and  https://ocv.me/dev/repro/avio_remuxing.png
[14:12:52 CEST] <JEEB> that's funky
[14:14:49 CEST] <JEEB> although there are some cases where the internal stuff will attempt to retry
[14:14:58 CEST] <JEEB> rw_timeout and follow params f.ex.
[14:15:04 CEST] <JEEB> but I don't think that's it
[14:18:41 CEST] <trfl> any idea where I should start looking? maybe dumping the stack on each call?
[14:46:21 CEST] <LimeGolem> I'm trying to record my audio, but so far haven't been able to get anything other than either silence or a quiet, intermittent buzzing. Would anyone be able to walk me through what I need to do?
[19:31:37 CEST] <LimeGolem> can someone explain how to use ffmpeg to record my system audio? I've tried following the instructions at https://trac.ffmpeg.org/wiki/Capture/ALSA, but can only record silence or mic input
[21:11:28 CEST] <Filarius> its not actually ffmpeg question... but I want to get keyframe intervals in mp4, better it to be a graph. I use Windows OS
[21:12:41 CEST] <Filarius> I found few solution in internet, but its will make pretty much no so human-friendly
[21:44:11 CEST] <Hello71> LimeGolem: does it work with arecord
[21:44:28 CEST] <Hello71> Filarius: ffprobe -show_packets and scripting
[21:44:33 CEST] <Hello71> or show_frames
[21:45:09 CEST] <LimeGolem> Hello71, I haven't got it working with arecord, no
[21:50:26 CEST] <Hello71> well then how the hell is ffmpeg gonna work
[21:57:26 CEST] <LimeGolem> ok, let me ask this instead: can someone explain how to use arecord to record my system audio?
[22:05:22 CEST] <ChocolateArmpits> Would -vsync 1 -r 25 behave the same as -vf fps=25 ?
[22:48:27 CEST] <sazawal> I have image files which I want to combine into a video. I have used the command "ffmpeg -y -r 18 -f concat -safe 0 -i "list.txt" -c:v libx264 -vf "fps=18,format=yuv420p,scale=500:-2" out1.mp4" from a forum and it does the job but the resolution of the video is not good. Please help me understand the ffmpeg arguments.
[23:35:13 CEST] <fahadash> I have to concat 13 videos first 4 are MOV and rest are MP4. I used -f concat -safe 0 /path/to/contat.txt -c copy /path/to/output.MOV ; The resultant video only kept the first 4 videos intact, but after that the rest of the video was only audio with some still picture showing with some colored lines in the top. What did I do wrong?
[23:35:23 CEST] <fahadash> Should I not use -c copy? or -safe 0?
[23:39:28 CEST] <fahadash> Here is the output https://pastebin.com/bCz84gC2
[23:40:23 CEST] <JEEB> check with ffprobe -v verbose if the video format/level/profile etc match between the clips
[23:40:29 CEST] <JEEB> as in, input clips
[23:41:00 CEST] <fahadash> Should ffmpeg not just handle the mismatch format/level issues?
[23:41:02 CEST] <safinaskar> hi
[23:41:14 CEST] <safinaskar> i am piping raw video frames to ffmpeg
[23:41:22 CEST] <safinaskar> ffmpeg encodes them as .mkv
[23:41:44 CEST] <safinaskar> this frames comes _very_ rare, say, 1 frame in minute
[23:42:15 CEST] <safinaskar> and it seems ffmpeg doesn't write output to .mkv immideately after input frame came
[23:42:38 CEST] <safinaskar> but i want ffmpeg to record frame immideately
[23:42:47 CEST] <safinaskar> becase my computer can crash in any moment
[23:43:06 CEST] <safinaskar> and if my computer crashs, i want last generated frame be stored in output
[23:43:13 CEST] <safinaskar> here is actual ffmpeg command:
[23:44:05 CEST] <safinaskar> ffmpeg -loglevel warning -f rawvideo -pixel_format rgb32 -video_size ${W}x${H} -i pipe: -c:v libx264 -pix_fmt yuv444p -preset ultrafast -qp 0 out.mkv
[23:44:11 CEST] <safinaskar> so, what to do?
[23:45:10 CEST] <safinaskar> i see the following: i write first frame over pipe, then i wait indefinetely long, but ffmpeg doesn't write it immideately, the size of out.mkv is zero!!! and only if i close pipe, then ffmpeg actually writes file. i don't want this! help me
[23:47:48 CEST] <fahadash> I tried the output format MP4 and i continue to see first mov files showing correctly in the output the rest showing jerky still snapshots with correct audio
[23:48:41 CEST] <fahadash> Those first 4 MOV files were actually rotated versions of the same MP4 files with same format. I flipped them using rotate filter with yuvj420p format
[23:54:43 CEST] <fahadash> Let me try rotating all other videos 360 and save as MOV, may be that would make them uniform format
[00:00:00 CEST] --- Mon Oct  1 2018


More information about the Ffmpeg-devel-irc mailing list