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Rockbox mail archiveSubject: Re: MPEG Audio formatRe: MPEG Audio format
From: Bluechip <csbluechip_at_gmail.com>
Date: Sat, 14 Jan 2006 02:47:52 +0000 >>>CHANNELS? Eg. Some frames are 48KHz and other frames are 44.1KHz ...or >>>some frames in Stereo, some in Joint-Stereo? > >Dumb question since I've never really looked into how they're processed, >but isn't this what VBR (variable-bit-rate) MP3 files are? Each frame of >audio will vary in bitrate depending on the type of audio at that moment >for best overall compression? > >-id No such thing as a dumb question. Only dumb answers. VBR files change in BITRATE, that does not mean a change in CHANNEL MODE, SAMPLERATE, MPEG-VERSION or MPEG-LAYER This example output may help it all make more sense: _at_0x0021625C+0.1, 4721566 - 7835 MPEG audio frames | ,-- | | MPEG Version : MPEG Version 1 (ISO/IEC 11172-3) | | MPEG Layer : Layer III | | Samplerate : 44100 Hz | | Bitrate : VBR _at_ ABR = 184807 bpS [Match: 192 Kbps] | | Samples/Frame : 1152 | | Frame Time : 26.122449 mS | | | | Frame Count : 7835 -> 68.2% (of ALL frames) | | Frame Time : 0:03:24.669 | `-v | | (%'s below are for this block only) | | | +-- Channels : Joint Stereo [Xing index: 36] | | 35 -> 0.4% _at_ JS (only) | | 7800 -> 99.6% _at_ JS +M/S | | | +-- Emphasis : 7835 -> 100.0% _at_ No Emphasis | | | | --- Enabled ---- -+- --- Disabled --- | +-- Original : 7835 -> 100.0% | 0 -> 0.0% | +-- Copyright : 0 -> 0.0% | 7835 -> 100.0% | +-- Private : 0 -> 0.0% | 7835 -> 100.0% | | | | +-- Protected : 7835 -> 100.0% | 0 -> 0.0% | +-- Padding : 0 -> 0.0% | 7835 -> 100.0% | | ^ | `-- Bitrate : 1761 -> 22.5% _at_ 160 KbpS | 6074 -> 77.5% _at_ 192 KbpS [ABR Match] Received on 2006-01-14 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |