[FFmpeg-user] got black screen when recording on Ubuntu Server 14.04 LTS EC2 instance

[Radoslav Horák]

I installed ubuntu xfce4 and connected to it from WIndows via RDP (followed
this howto
https://aws.amazon.com/premiumsupport/knowledge-center/connect-to-linux-desktop-from-windows/
)

when I record via ffmpeg, I got blank screen
would you please advice?

TIA
Radoslav

Sun Oct 25 23:01:05 ubuntu ~ $ uname -a
Linux ip-172-31-17-224 3.13.0-66-generic #108-Ubuntu SMP Wed Oct 7 15:20:27
UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Sun Oct 25 23:01:06 ubuntu ~ $ echo $DISPLAY
:10.0

ubuntu at ip-172-31-17-224:~$ ffmpeg  -y  -s 1920x1080 -f x11grab -i :10.0 -f
alsa -i default -r 5 out.mkv
ffmpeg version N-76045-g97be5d4 Copyright (c) 2000-2015 the FFmpeg
developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --enable-avresample
--disable-debug --enable-nonfree --enable-gpl --enable-version3
--enable-libopencore-amrnb --enable-libopencore-amrwb
--disable-decoder=amrnb --disable-decoder=amrwb --enable-libpulse
--enable-libdcadec --enable-libfreetype --enable-libx264 --enable-libx265
--enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus
--enable-libvpx --enable-libspeex --enable-libass --enable-avisynth
--enable-libsoxr --enable-libxvid --enable-libvo-aacenc --enable-libvidstab
  libavutil      55.  4.100 / 55.  4.100
  libavcodec     57.  6.100 / 57.  6.100
  libavformat    57.  4.100 / 57.  4.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 11.100 /  6. 11.100
  libavresample   3.  0.  0 /  3.  0.  0
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.100 /  2.  0.100
  libpostproc    54.  0.100 / 54.  0.100
[x11grab @ 0x2d005e0] XFixes not available, cannot draw the mouse.
Input #0, x11grab, from ':10.0':
  Duration: N/A, start: 1445814844.569813, bitrate: N/A
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 640x480, 29.97
fps, 29.97 tbr, 1000k tbn, 29.97 tbc
Guessed Channel Layout for  Input Stream #1.0 : stereo
Input #1, alsa, from 'default':
  Duration: N/A, start: 1445814844.638938, bitrate: 1536 kb/s
    Stream #1:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
No pixel format specified, yuv444p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 0x2d26740] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
AVX AVX2 FMA3 LZCNT BMI2
[libx264 @ 0x2d26740] profile High 4:4:4 Predictive, level 4.0, 4:4:4 8-bit
[libx264 @ 0x2d26740] 264 - core 142 r2491 24e4fed - H.264/MPEG-4 AVC codec
- Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1
ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00
mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11
fast_pskip=1 chroma_qp_offset=4 threads=1 lookahead_threads=1
sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0
constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1
weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=5 scenecut=40
intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0
qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'out.mkv':
  Metadata:
    encoder         : Lavf57.4.100
    Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p,
1920x1080, q=-1--1, 5 fps, 1k tbn, 5 tbc
    Metadata:
      encoder         : Lavc57.6.100 libx264
    Stream #0:1: Audio: vorbis (libvorbis) (oV[0][0] / 0x566F), 48000 Hz,
stereo, fltp
    Metadata:
      encoder         : Lavc57.6.100 libvorbis
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
  Stream #1:0 -> #0:1 (pcm_s16le (native) -> vorbis (libvorbis))
Press [q] to stop, [?] for help
[alsa @ 0x2d07a20] Thread message queue blocking; consider raising the
thread_queue_size option (current value: 8)