[FFmpeg-user] generating silent audio streams simultaneous with lavfi / generated video

[Dave P]

On Wed, Jul 1, 2015 at 2:45 AM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> James Heliker <james.heliker <at> gmail.com> writes:
>
> > C:\ffmpeg.exe -f lavfi -i color=c=black:s=1920x1080
> > -frames:v 10
>
> > -r 29.97
>
> The color filter has a rate option.
>
> > However that results in a file with only video
> > stream - no audio.
>
> You failed to provide an input audio stream to
> ffmpeg, I usually use:
> ffmpeg -f s16le -i /dev/zero
> The anullsrc filter should work fine on Windows.
>
> Carl Eugen
>
>
Perhaps something like this could get you pretty close (I changed the
drawtext font to suit my install):

C:\ffmpeg\bin>ffmpeg.exe -f lavfi -i color=c=black:r=29.97:s=1920x1080 -f
lavfi
-i aevalsrc=0:s=48000 -vcodec mpeg2video -pix_fmt yuv422p -non_linear_quant
1 -f
lags +ildct+ilme -top 1 -dc 10 -intra_vlc 1 -qmax 3 -lmin "1*QP2LAMBDA"
-rc_max_
vbv_use 1 -rc_min_vbv_use 1 -g 15 -bf 2 -r ntsc -b:v 50M -minrate 50M
-maxrate 5
0M -bufsize 8M -vtag xd5c -frames:v 10 -acodec pcm_s24le -filter_complex
"[0:v]d
rawtext=subfont.ttf:fontcolor=white:fontsize=48:fontcolor=white:x=(w-text_w)/2:y
=(h-text_h-line_h)/2:text='testing'[video];[1:a]asplit=8[a0][a1][a2][a3][a4][a5]
[a6][a7]" -map "[video]" -map "[a0]" -map "[a1]" -map "[a2]" -map "[a3]"
-map "[
a4]" -map "[a5]" -map "[a6]" -map "[a7]" -shortest -report -y
C:\Users\davep\des
ktop\slate_output.mxf
ffmpeg started on 2015-07-01 at 10:29:00
Report written to "ffmpeg-20150701-102900.log"
ffmpeg version N-73319-g9c010ba Copyright (c) 2000-2015 the FFmpeg
developers
  built with gcc 4.9.2 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads
--enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls
--enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b
--enable-libcaca --
enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm
--enable-l
ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
--enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp
--en
able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
--ena
ble-libtwolame --enable-libvidstab --enable-libvo-aacenc
--enable-libvo-amrwbenc
 --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp
--enabl
e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma
--ena
ble-decklink --enable-zlib
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 46.100 / 56. 46.100
  libavformat    56. 40.100 / 56. 40.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 19.100 /  5. 19.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, lavfi, from 'color=c=black:r=29.97:s=1920x1080':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080
[SAR 1:
1 DAR 16:9], 29.97 tbr, 29.97 tbn, 29.97 tbc
Input #1, lavfi, from 'aevalsrc=0:s=48000':
  Duration: N/A, start: 0.000000, bitrate: 3072 kb/s
    Stream #1:0: Audio: pcm_f64le, 48000 Hz, mono, dbl, 3072 kb/s
Output #0, mxf, to 'C:\Users\davep\desktop\slate_output.mxf':
  Metadata:
    encoder         : Lavf56.40.100
    Stream #0:0: Video: mpeg2video (xd5c / 0x63356478), yuv422p, 1920x1080
[SAR
1:1 DAR 16:9], q=2-3, 50000 kb/s, 29.97 fps, 29.97 tbn, 29.97 tbc (default)
    Metadata:
      encoder         : Lavc56.46.100 mpeg2video
    Stream #0:1: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:2: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:3: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:4: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:5: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:6: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:7: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
    Stream #0:8: Audio: pcm_s24le, 48000 Hz, mono, s32, 1152 kb/s
    Metadata:
      encoder         : Lavc56.46.100 pcm_s24le
Stream mapping:
  Stream #0:0 (rawvideo) -> drawtext
  Stream #1:0 (pcm_f64le) -> asplit
  drawtext -> Stream #0:0 (mpeg2video)
  asplit:output0 -> Stream #0:1 (pcm_s24le)
  asplit:output1 -> Stream #0:2 (pcm_s24le)
  asplit:output2 -> Stream #0:3 (pcm_s24le)
  asplit:output3 -> Stream #0:4 (pcm_s24le)
  asplit:output4 -> Stream #0:5 (pcm_s24le)
  asplit:output5 -> Stream #0:6 (pcm_s24le)
  asplit:output6 -> Stream #0:7 (pcm_s24le)
  asplit:output7 -> Stream #0:8 (pcm_s24le)
Press [q] to stop, [?] for help
[mxf @ 00000000003badc0] -d10_channelcount requires MXF D-10 and will be
ignored
    Last message repeated 7 times
[mxf @ 00000000003badc0] missing frames
frame=   10 fps=0.0 q=0.0 Lsize=    1969kB time=00:00:00.30
bitrate=53714.6kbits
/s
video:1792kB audio:336kB subtitle:0kB other streams:0kB global headers:0kB
muxin
g overhead: unknown