Dropping audio in ffmpeg conversion

[William A. Mahaffey III]

On 12/06/14 17:17, Waitman Gobble wrote:
> On Sat, Dec 6, 2014 at 2:43 PM, Polytropon <freebsd at edvax.de> wrote:
>
>> I'm searching for a convenient way to drop audio from
>> an AVI file (video and audio) upon conversion to MP4.
>> My tool of choice is ffmpeg, which works perfectly fine
>> with the default options:
>>
>>          % ffmpeg -i in.avi out.mp4
>>
>> The quality loss, the "pixelated" and "blocky" output
>> is what I expect, and the result file is small. I just
>> can't find a way to get rid of audio (which I don't
>> need). Reading "man ffmeg" told me about "sinks" which
>> "do nothing", but I'm too stupid to conclude how to use
>> them properly. What I want to have is a converted video
>> with no audio track at all (also smaller file size).
>>
>> Can ffmpeg do this, or do I have to "preprocess" the
>> input file with mencoder somehow?
>>
>> Does anybody know how to proceed?
>>
>>
>>
>> --
>> Polytropon
>> Magdeburg, Germany
>> Happy FreeBSD user since 4.0
>> Andra moi ennepe, Mousa, ...
>> _______________________________________________
>> freebsd-questions at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>> To unsubscribe, send any mail to "
>> freebsd-questions-unsubscribe at freebsd.org"
>>
>
> I think it's -an switch.
>

Out of curiosity from this thread, I decided to install ffmpeg & 
possibly play around w/ it. Here's the transcript:

[root at kabini1, /etc, 12:20:50pm] 332 % pkg install -y ffmpeg
Updating FreeBSD repository catalogue...
Fetching meta.txz: 100%   968 B   1.0k/s    00:01
Fetching digests.txz: 100%    2 MB 341.9k/s    00:06
Fetching packagesite.txz: 100%    5 MB 354.7k/s    00:15
Removing expired repository entries: 100%
Processing new repository entries: 100%
FreeBSD repository update completed. 23602 packages processed:
   17694 updated, 147 removed and 41 added.
Updating FreeBSD_new_xorg repository catalogue...
FreeBSD_new_xorg repository is up-to-date.

nspluginwrapper-1.4.4_4 is locked and may not be modified
The following 15 packages will be affected (of 0 checked):

New packages to be INSTALLED:
         ffmpeg: 2.3.5_3,1 [FreeBSD]
         linux_base-f10: 10_9 [FreeBSD]
         linux-f10-xorg-libs: 7.4_1 [FreeBSD]
         linux-f10-fontconfig: 2.6.0_1 [FreeBSD]
         linux-f10-expat: 2.0.1_1 [FreeBSD]
         linux-f10-pango: 1.28.3_1 [FreeBSD]
         linux-f10-png: 1.2.37_2 [FreeBSD]
         linux-f10-cairo: 1.8.0_3 [FreeBSD]
         linux-f10-gtk2: 2.14.7_5 [FreeBSD]
         linux-f10-tiff: 3.8.2 [FreeBSD]
         linux-f10-jpeg: 6b [FreeBSD]
         linux-f10-atk: 1.24.0_1 [FreeBSD]
         schroedinger: 1.0.11_3 [FreeBSD]
         libx264: 0.142.2455 [FreeBSD]
         opencv-core: 2.4.9_1 [FreeBSD]

The process will require 209 MB more space.
33 MB to be downloaded.
Fetching ffmpeg-2.3.5_3,1.txz: 100%    8 MB 380.5k/s    00:24
Fetching linux_base-f10-10_9.txz: 100%   16 MB 366.0k/s    00:48
Fetching linux-f10-xorg-libs-7.4_1.txz: 100%    1 MB 316.6k/s 00:05
Fetching linux-f10-fontconfig-2.6.0_1.txz: 100%  118 kB 121.1k/s 00:01
Fetching linux-f10-expat-2.0.1_1.txz: 100%   65 kB  67.2k/s 00:01
Fetching linux-f10-pango-1.28.3_1.txz: 100%  274 kB 281.3k/s 00:01
Fetching linux-f10-png-1.2.37_2.txz: 100%  150 kB 154.2k/s 00:01
Fetching linux-f10-cairo-1.8.0_3.txz: 100%  353 kB 361.8k/s 00:01
Fetching linux-f10-gtk2-2.14.7_5.txz: 100%    3 MB 351.0k/s 00:09
Fetching linux-f10-tiff-3.8.2.txz: 100%  241 kB 247.5k/s    00:01
Fetching linux-f10-jpeg-6b.txz: 100%  115 kB 118.1k/s    00:01
Fetching linux-f10-atk-1.24.0_1.txz: 100%  144 kB 148.0k/s 00:01
Fetching schroedinger-1.0.11_3.txz: 100%  396 kB 405.9k/s 00:01
Fetching libx264-0.142.2455.txz: 100%  407 kB 208.4k/s    00:02
Fetching opencv-core-2.4.9_1.txz: 100%    1 MB 401.3k/s    00:04
Checking integrity... done (11 conflicting)
Checking integrity... done (0 conflicting)
Conflicts with the existing packages have been found.
One more solver iteration is needed to resolve them.
The following 5 packages will be affected (of 0 checked):

Installed packages to be REMOVED:
         nspluginwrapper-1.4.4_4

New packages to be INSTALLED:
         schroedinger: 1.0.11_3 [FreeBSD]
         libx264: 0.142.2455 [FreeBSD]
         opencv-core: 2.4.9_1 [FreeBSD]
         ffmpeg: 2.3.5_3,1 [FreeBSD]

The process will require 49 MB more space.

nspluginwrapper-1.4.4_4 is locked and may not be modified
  whew !!!! that took (43.233 cpu + 5.569 sys) sec., 2:50.10 elapsed 
time tot, 28.6% CPU efficiency
         (207 text, 2549 data, 46500 max) KB, (0+1411) io, 7318 pfs + 0 
swaps
[root at kabini1, /etc, 6:03:18pm] 333 %

in short, it tried to install linux-f10, rather than relying on linux-c6 
.... pkg bug ? ffmpeg package bug ? pilot error ? TIA for any 
clarifications ....

-- 

	William A. Mahaffey III

  ----------------------------------------------------------------------

	"The M1 Garand is without doubt the finest implement of war
	 ever devised by man."
                            -- Gen. George S. Patton Jr.