Gentoo Archives: gentoo-user

From: Michael Mol <mikemol@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: libav/ffmpeg's bitrate options have no effect in Gentoo
Date: Tue, 06 Sep 2011 14:43:21
Message-Id: CA+czFiAP34Pq7QFHUWem48kZC3p147EmUZOLSmkhL9M3wOBrmw@mail.gmail.com
In Reply to: Re: [gentoo-user] Re: libav/ffmpeg's bitrate options have no effect in Gentoo by "Casper Ti. Vector"
1 On Tue, Sep 6, 2011 at 8:34 AM, Casper Ti. Vector
2 <caspervector@×××××.com> wrote:
3 > On Tue, Sep 06, 2011 at 03:09:13PM +0300, Nikos Chantziaras wrote:
4 >> So try with avconv instead.  But for MP3, you should probably be using
5 >> LAME with a VBR quality setting instead.
6 > In fact I don't quite know what you mean in this sentence :|
7
8 'lame' is an MP3 encoder. VBR is 'variable bitrate', which means that
9 high-information sections in the input stream get more bits in the
10 output bitstream, and low-information sections in the input stream get
11 fewer bits in the output bitstream. An encoded song might use 192Kb/s
12 for a few seconds, and then 32Kb/s for a second, and jump up to
13 256Kb/s for a quarter-second before dropping down to 128Kb/s--but
14 still sound to your ear like it was encoded at a constant bitrate of
15 256Kb/s. All so that audio fidelity is maintained when there's
16 something there to actually hear.
17
18 Or, more simply:
19 * 'lame' is an MP3 encoder
20 * 'VBR' stands for 'variable bitrate', and offers a better
21 size/quality tradeoff scale than saying "I want 192Kb/s"
22
23 --
24 :wq

Replies

Subject Author
Re: [gentoo-user] Re: libav/ffmpeg's bitrate options have no effect in Gentoo "Casper Ti. Vector" <caspervector@×××××.com>