[FFmpeg-user] taking audio and video inputs from different devices

[Ricardo Kleemann]

> On Jul 26, 2015, at 3:28 AM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> 
> Ricardo Kleemann <ricardo <at> americasnet.com> writes:
> 
>> Input #0, avfoundation, from 'none:1':
>>  Duration: N/A, start: 28853.224036
> 
>> Input #1, decklink, from 'UltraStudio Mini Recorder <at> 9':
>>  Duration: N/A, start: 0.000000
> 
> The different start times are an issue.
> 

> Does it work if you only record audio?
> 

I’m not sure where the crazy start time comes from, but yes, the audio works fine if done separately. 


Maybe I need to do something differently to mix the audio and video?

$ ffmpeg -f avfoundation -i "none:1" -ac 2 -vn audio.mp4
ffmpeg version N-73104-g7604358 Copyright (c) 2000-2015 the FFmpeg developers
  built with Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-ffplay --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-decklink --extra-cflags=-I/Users/ptl/blackmagicsdk/Mac/include --extra-ldflags=-L/Users/ptl/blackmagicsdk/Mac/include
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 44.100 / 56. 44.100
  libavformat    56. 38.100 / 56. 38.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 17.100 /  5. 17.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, avfoundation, from 'none:1':
  Duration: N/A, start: 66610.243492, bitrate: 2822 kb/s
    Stream #0:0: Audio: pcm_f32le, 44100 Hz, stereo, flt, 2822 kb/s
Output #0, mp4, to 'audio.mp4':
  Metadata:
    encoder         : Lavf56.38.100
    Stream #0:0: Audio: aac (libfdk_aac) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, s16, 128 kb/s
    Metadata:
      encoder         : Lavc56.44.100 libfdk_aac
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_f32le (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
size=     330kB time=00:00:20.81 bitrate= 129.9kbits/s    
video:0kB audio:326kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.301418%


> Carl Eugen
> 
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