Re: MPEG Layer3 - Kto ma jakies doswiadczenia?

Autor: Tomasz Leszczynski (zeton_at_waw.pdi.net)
Data: Sun 23 Feb 1997 - 16:16:50 MET

On 23 Feb 97 at 15:08, Andrzej Paszkowski pisal(a):

> Witam.
> Interesuje mnie MPEG Layer3.
> Mam odtwarzacz WinPlay3 ale bardzo przerywa podczas odtwarzania probki 44.1
> kHz 96 kbit/s. Nie wiem czy to wina zbyt slabego komputera - 486dx4 120 MHz
> 16 MB RAM, czy tez moze karty muzycznej - Gallant SC66 16bit, a moze
> odtwarzarki WinPlay3, niestety nie mam innej.
> Moze ktos ma jakies doswiadczenia w tym zakresie?
>
> Andrzej Paszkowski
> paszczak_at_free.polbox.pl

Za slaby komputer prawdopodobnie. U mnie tez rwie (486 DX4-100) :-(
Trzeba albo zmienic na downmix (czyli na mono) albo zmniejszyc
czestotliwosc odtwarzania na "half". Albo i jedno i drugie :-(

Z FAQ dolaczonego do programu l3enc v.2.61

[start]

Real-time Layer-3 players

WinPlay3

"WinPlay3" allows the decoding simply by software on any Pentium
PC in real time. A 80486 class CPU with a built-in floating-point-unit
will also allow some limited operation. For the availability of
supported modes, please refer to the following performance matrix:

<wlacz font proporcjonalny bo ci sie rozjedzie tabelka :-) >

                Pentium 486DX2-66 486DX-50 486DX-33
MPEG-1 stereo ok - - -
MPEG-1 downmix* ok ok - -
MPEG-1 mono ok ok ok -
MPEG-2 stereo ok ok ok -
MPEG-2 downmix* ok ok ok ok
MPEG-2 mono ok ok ok ok
*downmix: the original stereo signal will be played back as a mono
signal "MPEG-1" = "MPEG-1 Layer-3", i.e. sample rates 32, 44.1 or 48
kHz "MPEG-2" = "MPEG-2 Layer-3", i.e. sample rates 16, 22.05 or 24 kHz

On a Pentium-90, WinPlay3 consumes less than 30 % of the CPU power to
decode Layer-3 stereo @ 44.1 kHz, or around 5 % of the CPU power to
decode Layer-3 mono @ 16 kHz. At least, a 8-bit stereo sound card is
required. For full quality audio, a 16-bit card is recommended. The
card&acutes MCI driver should support sampling frequencies from 8 kHz
to 48 kHz. A standard VGA graphics card is required. As WinPlay3
buffers up to 4 seconds of sound data due to the limitations of the
Microsoft Windows multitasking architecture, around 1 MByte free
physical memory must be available.

[stop]

Z powazaniem
Tomasz Leszczynski

P.S. Niedawno (przed chwila) toczyla sie tutaj pasjonujaca dyskusja o
Layer3, polecam zajrzec do archiwum peceta.

To archiwum zostało wygenerowane przez hypermail 2.1.7 : Tue 18 May 2004 - 15:55:55 MET DST