[FFmpeg-user] mono or stereo? ffmpeg converts or phone?
seandarcy2 at gmail.com
Mon Apr 28 23:53:15 CEST 2014
On 04/28/2014 03:04 AM, Carl Eugen Hoyos wrote:
> Sean Darcy <seandarcy2 <at> gmail.com> writes:
>> So for a bitrate of let's say 48000, am I better off
>> converting to mono in ffmpeg ( -ac 1 ) or leaving it
>> stereo and letting the phone convert it?
> You may be better off (and if playback is only mono, you
> don't loose anything) but please understand that you cannot
> double the quality / half the bitrate.
> The chosen encoder is much more important, if your phone
> does not support opus, make sure to choose libfdk-aac.
> Carl Eugen
I don't have an audio book reader that can read opus installed on my
phone. I don't even know if there is one. I do use opus for voip: it's
But back to the OP. I am using libfdk-aac. I understand that 24000 mono
will not equal 48000 stereo.
My real question is: how does ffmpeg downmix 2 -> 1. I assume it doesn't
just take one channel. Does it "average" in some way the two channels?
I also assume whatever ffmpeg does, it does it better the android code
on a phone doing it in realtime.
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