[FFmpeg-user] generating silent audio streams simultaneous with lavfi / generated video
Paul B Mahol
onemda at gmail.com
Wed Jul 1 21:44:56 CEST 2015
On 7/1/15, James Heliker <james.heliker at gmail.com> wrote:
> On 7/1/2015 7:32 AM, Dave P wrote:
>> 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
>
> Thanks Carl and Dave! Is there any benefit or drawback to using aevalsrc
> instead of anullsrc?
aevalsrc could be little slower.
>
>
>> 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
>> _______________________________________________
>> ffmpeg-user mailing list
>> ffmpeg-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
More information about the ffmpeg-user
mailing list