Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #201436 > unrolled thread

Why does sound encoded with mencoder crackle in debian stretch but not in buster?

Back to article view | Back to linux.debian.user

Contents

  Why does sound encoded with mencoder crackle in debian stretch but  not in buster? Markus Grunwald <markus@the-grue.de> - 2018-10-19 16:20 +0200
    Re: Why does sound encoded with mencoder crackle in debian stretch  but not in buster? Dan Ritter <dsr@randomstring.org> - 2018-10-19 16:30 +0200
      Re: Why does sound encoded with mencoder crackle in debian stretch  but not in buster? Markus Grunwald <markus@the-grue.de> - 2018-10-19 16:50 +0200
        Re: Why does sound encoded with mencoder crackle in debian stretch  but not in buster? Dan Ritter <dsr@randomstring.org> - 2018-10-19 17:40 +0200

#201436 — Why does sound encoded with mencoder crackle in debian stretch but not in buster?

I'm transcoding some TV Series with mencoder. I wrote a script where the
core is:

mencoder 00001.ts -o 00001.avi -passlogfile /tmp/tmp.VQ6WZm1tSo/pass.log
-demuxer lavf -nosub -vf softskip,harddup -aspect 16:9 -aid 0 -oac lavc
-lavcopts acodec=ac3:abitrate=128 -ovc x264 -x264encopts
pass=1:bitrate=800:nointerlaced:force_cfr:frameref=3:mixed_refs:bframes=4:b_adapt=2:b_pyramid=normal:weight_b:weightp=1:direct_pred=auto:aq_mode=1:me=umh:me_range=16:subq=7:nombtree:psy_rd=0.8,0.2:chroma_me:trellis=1:cabac:deblock:8x8dct:partitions=p8x8,b8x8,i8x8,i4x4:nofast_pskip:nodct_decimate:threads=auto:keyint=250:keyint_min=25

This is probably the only interesting part for this post:

-oac lavc -lavcopts acodec=ac3:abitrate=128

I wrote that script on my laptop, a debian buster machine. Everything is
fine here. But when I let the script run on the machine where all the
recordings are stored (a debian stretch machine), the sound is
disturbed. Some kind of ~6Hz crackle. Video is ok.

IMHO it has to do with some different version of a binary or library.
That's why I tried it with different audio encoder:

-oac mp3lame -lameopts preset=medium

Still the same.

The versions for mencoder differ a tiny bit on both machines:

ii  mencoder       2:1.3.0-6    amd64        MPlayer's Movie Encoder
ii  mencoder       2:1.3.0-8+b4 amd64        MPlayer's Movie Encoder

But the differences seem quite minor:

https://metadata.ftp-master.debian.org/changelogs//main/m/mplayer/mplayer_1.3.0-8_changelog

Any ideas how I get that working on the stretch machine?
-- 
Markus Grunwald
https://www.the-grue.de/~markus/markus_grunwald.gpg

[toc] | [next] | [standalone]

#201437 — Re: Why does sound encoded with mencoder crackle in debian stretch but not in buster?

On Fri, Oct 19, 2018 at 04:09:19PM +0200, Markus Grunwald wrote:
> I'm transcoding some TV Series with mencoder. I wrote a script where the
> core is:
> 
> mencoder 00001.ts -o 00001.avi -passlogfile /tmp/tmp.VQ6WZm1tSo/pass.log
> -demuxer lavf -nosub -vf softskip,harddup -aspect 16:9 -aid 0 -oac lavc
> -lavcopts acodec=ac3:abitrate=128 -ovc x264 -x264encopts
> pass=1:bitrate=800:nointerlaced:force_cfr:frameref=3:mixed_refs:bframes=4:b_adapt=2:b_pyramid=normal:weight_b:weightp=1:direct_pred=auto:aq_mode=1:me=umh:me_range=16:subq=7:nombtree:psy_rd=0.8,0.2:chroma_me:trellis=1:cabac:deblock:8x8dct:partitions=p8x8,b8x8,i8x8,i4x4:nofast_pskip:nodct_decimate:threads=auto:keyint=250:keyint_min=25
> 
> This is probably the only interesting part for this post:
> 
> -oac lavc -lavcopts acodec=ac3:abitrate=128
> 
> I wrote that script on my laptop, a debian buster machine. Everything is
> fine here. But when I let the script run on the machine where all the
> recordings are stored (a debian stretch machine), the sound is
> disturbed. Some kind of ~6Hz crackle. Video is ok.
> 
> IMHO it has to do with some different version of a binary or library.
> That's why I tried it with different audio encoder:
> 
> -oac mp3lame -lameopts preset=medium
> 
> Still the same.

Does 
-oac copy
do the same thing?

-dsr-

[toc] | [prev] | [next] | [standalone]

#201438 — Re: Why does sound encoded with mencoder crackle in debian stretch but not in buster?

Hello Dan,

> Does
> -oac copy
> do the same thing?
No, that works!

Strange.


-- 
Markus Grunwald
https://www.the-grue.de/~markus/markus_grunwald.gpg

[toc] | [prev] | [next] | [standalone]

#201444 — Re: Why does sound encoded with mencoder crackle in debian stretch but not in buster?

On Fri, Oct 19, 2018 at 04:48:17PM +0200, Markus Grunwald wrote:
> Hello Dan,
> 
> > Does
> > -oac copy
> > do the same thing?
> No, that works!
> 
> Strange.

No, no, it means that you have successfully identified the
source of the problem as being ffmpeg's audio conversion.

On the other hand, it also gives you a workaround: original
audio is rarely an unsupported format and is rarely a major
component of the file size, so why not use it?

-dsr-

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.user

csiph-web