[FFmpeg-devel] Decklink question

ffmpeg at dx9s.net ffmpeg at dx9s.net
Fri Sep 29 04:44:45 EEST 2017


On 2017-09-28 13:32, Marton Balint wrote:
> You should try the latest ffmpeg git master, RGB support just got
> recently committed, and if you are capturing from HDMI maybe you have
> to use an RGB format. Until now, ffmpeg always requested YUV, and I am
> not sure if decklink is supposed to do a software conversion by
> default or not.

Okay.. Build a custom local build based on commit 
3d4f8b9184a4693c577e0b73496e6cc1989c6bbf did some initial testing but 
still need to test the RGB format:

dx at x299:~/capture$ ffmpeg -format_code Hp59 -f decklink -video_input 
hdmi -audio_input embedded -raw_format yuv422p10 -i 'DeckLink Studio 4K' 
-acodec pcm_s24le -vcodec dnxhd -vf 
scale=1920x1080,fps=60000/1001,format=yuv422p10 -b:v 440M out.mov
ffmpeg version N-87614-g3d4f8b9-dx9s-decklink Copyright (c) 2000-2017 
the FFmpeg developers
   built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
   configuration: --prefix=/usr/local/ffmpeg 
--extra-version=dx9s-decklink --build-suffix=-dx9s-decklink 
--toolchain=hardened --cc=cc --cxx=g++ --enable-gpl --enable-shared 
--disable-stripping --disable-decoder=libopenjpeg --enable-avresample 
--enable-avisynth --enable-gnutls --enable-ladspa --enable-libass 
--enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio 
--enable-libflite --enable-libfontconfig --enable-libfreetype 
--enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug 
--enable-libmp3lame --enable-libopenjpeg --enable-libopus 
--enable-libpulse --enable-librtmp --enable-libshine --enable-libsnappy 
--enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora 
--enable-libtwolame --enable-libvorbis --enable-libvpx 
--enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid 
--enable-libzvbi --enable-openal --enable-opengl --enable-libdc1394 
--enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 
--enable-libopencv --enable-decklink --enable-nonfree
   libavutil      55. 77.101 / 55. 77.101
   libavcodec     57.106.104 / 57.106.104
   libavformat    57. 82.102 / 57. 82.102
   libavdevice    57.  9.101 / 57.  9.101
   libavfilter     6.106.100 /  6.106.100
   libavresample   3.  6.  0 /  3.  6.  0
   libswscale      4.  7.103 /  4.  7.103
   libswresample   2.  8.100 /  2.  8.100
   libpostproc    54.  6.100 / 54.  6.100
[decklink @ 0x55d886094300] Found Decklink mode 1920 x 1080 with rate 
59.94
[decklink @ 0x55d886094300] Frame received (#1) - No input signal 
detected - Frames dropped 1
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'DeckLink Studio 4K':
   Duration: N/A, start: 0.000000, bitrate: 2653092 kb/s
     Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
     Stream #0:1: Video: v210 (V210 / 0x30313256), 
yuv422p10le(progressive), 1920x1080, 2651556 kb/s, 59.94 tbr, 1000k tbn, 
1000k tbc
Stream mapping:
   Stream #0:1 -> #0:0 (v210 (native) -> dnxhd (native))
   Stream #0:0 -> #0:1 (pcm_s16le (native) -> pcm_s24le (native))
Press [q] to stop, [?] for help
Output #0, mov, to 'out.mov':
   Metadata:
     encoder         : Lavf57.82.102
     Stream #0:0: Video: dnxhd (DNXHD) (AVdn / 0x6E645641), yuv422p10le, 
1920x1080, q=2-1024, 440000 kb/s, 59.94 fps, 60k tbn, 59.94 tbc
     Metadata:
       encoder         : Lavc57.106.104 dnxhd
     Stream #0:1: Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, stereo, 
s32, 2304 kb/s
     Metadata:
       encoder         : Lavc57.106.104 pcm_s24le
frame=   90 fps= 62 q=1.0 Lsize=   81065kB time=00:00:01.50 
bitrate=442279.7kbits/s speed=1.03x
video:80640kB audio:422kB subtitle:0kB other streams:0kB global 
headers:0kB muxing overhead: 0.003102%

output file is black (no bars or anything) and suspect audio is same as 
before... Initially still see same messages (16 bit audio and no Input 
signal detected)

Will report back once I figure out how to request RGB from the recent 
patch you mentions about RGB.

(is that still too much information)

--Doug (dx9s)



More information about the ffmpeg-devel mailing list