5.1 to stereo downmix

Useful and helpful Windows specific command line samples and examples.
pm1315
Posts: 2
Joined: Fri Mar 21, 2014 4:26 am

Re: 5.1 to stereo downmix

Post by pm1315 » Thu Apr 24, 2014 5:58 pm

svnpenn,

After trying your script and the one provided by Robert Collier in the Doom forum, on a couple of files,
I think yours is the one I prefer, as it actually bumps the center channel volume up -- I want to hear
the dialogue more clearly. I had to boost the overall volume a little bit on one of my files, and after
using ffmpeg's 'volumedetect' to examine the levels, I used the following script on the source:

-filter:a "pan=stereo|FL < FL + 1.414FC + .5BL + .5SL|FR < FR + 1.414FC + .5BR + .5SR, volume=1.25"

Thanks for your work.

pandy
Posts: 200
Joined: Mon Feb 24, 2014 1:46 pm

Re: 5.1 to stereo downmix

Post by pandy » Mon May 19, 2014 1:33 pm

Sorry for asking but what is wrong with -af aformat=sample_fmts=fltp:channel_layouts=downmix

svnpenn
Posts: 263
Joined: Tue Nov 01, 2011 12:19 am

Re: 5.1 to stereo downmix

Post by svnpenn » Mon May 19, 2014 2:00 pm

pandy wrote:Sorry for asking but what is wrong with -af aformat=sample_fmts=fltp:channel_layouts=downmix
Did you even read the thread

svnpenn
Posts: 263
Joined: Tue Nov 01, 2011 12:19 am

Re: 5.1 to stereo downmix

Post by svnpenn » Mon Jun 02, 2014 10:41 pm

I have updated the original post with a shorter command!

rogerdpack
Posts: 1877
Joined: Fri Aug 05, 2011 9:56 pm

Re: 5.1 to stereo downmix

Post by rogerdpack » Tue Jun 03, 2014 1:41 pm

svnpenn wrote:
llogan wrote:Jokes aside, have you actually tried submitting a patch to FFmpeg? That is how contributions are usually made to the project. I don't understand your negative attitude towards patch submissions.
I do submit patches, when I feel like it.

article.gmane.org/gmane.comp.version-control.git/244180

In this case I dont feel like it, so submit it yourself if you care so much.
If anybody does have a patch I'd be happy to submit it upstream for them.

svnpenn
Posts: 263
Joined: Tue Nov 01, 2011 12:19 am

Re: 5.1 to stereo downmix

Post by svnpenn » Tue Jun 03, 2014 3:33 pm

rogerdpack wrote: If anybody does have a patch I'd be happy to submit it upstream for them.
If they would be interested in merging it I could make a patch

stackoverflow.com/a/24007019

Changes need to be made in

libswresample/swresample.c

and

libswresample/rematrix.c

rogerdpack
Posts: 1877
Joined: Fri Aug 05, 2011 9:56 pm

Re: 5.1 to stereo downmix

Post by rogerdpack » Tue Jun 03, 2014 3:42 pm

svnpenn wrote:
rogerdpack wrote: If anybody does have a patch I'd be happy to submit it upstream for them.
If they would be interested in merging it I could make a patch

stackoverflow.com/a/24007019

Changes need to be made in

libswresample/swresample.c

and

libswresample/rematrix.c
OK especially if you have some type of input audio file that demonstrates the problem [and the patch fixes it] that would help.
Thanks!
-roger-

svnpenn
Posts: 263
Joined: Tue Nov 01, 2011 12:19 am

Re: 5.1 to stereo downmix

Post by svnpenn » Tue Jun 03, 2014 3:53 pm

rogerdpack wrote: OK especially if you have some type of input audio file that demonstrates the
problem [and the patch fixes it] that would help.
Is a GitHub pull request the preferred way to do this?

rogerdpack
Posts: 1877
Joined: Fri Aug 05, 2011 9:56 pm

Re: 5.1 to stereo downmix

Post by rogerdpack » Tue Jun 03, 2014 5:22 pm

svnpenn wrote:
rogerdpack wrote: OK especially if you have some type of input audio file that demonstrates the
problem [and the patch fixes it] that would help.
Is a GitHub pull request the preferred way to do this?
that would work, basically I need a .patch file that's it.

svnpenn
Posts: 263
Joined: Tue Nov 01, 2011 12:19 am

Re: 5.1 to stereo downmix

Post by svnpenn » Tue Jun 03, 2014 5:25 pm

rogerdpack wrote: that would work, basically I need a .patch file that's it.
I dont understand what you are getting at here. Why do *you* need a patch?
Unless you have commit rights or want to take credit for the patch I dont see
the point.

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