56 lines
2.2 KiB
Text
56 lines
2.2 KiB
Text
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The flag XMP_FLAGS_FIXLOOP halves sample loop start values. You may
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need to use it with modules where autodetection is either impossible
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or unreliable.
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Case 1: Bad conversion from Soundtracker to M.K.
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In Soundtracker and derivatives using 15 instrument modules the loop
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start is given in bytes instead of 16 bit words [1]. Many modules
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have been converted from 15 instrument to 31 instrument format assuming
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that the loop start was in 16 bit words instead of bytes, resulting in
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broken loops [2]. In this case, use XMP_FLAGS_FIXLOOP to play the module
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correctly.
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An example of damaged module is "mod.souvenir of china"
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Case 2: NoisePacker v1 modules
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According to Asle [3], the only difference between NoisePacker 1.0
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and 2.0 is the loop start value. This situation is very hard to
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detect, and XMP_FLAGS_FIXLOOP is needed to play NoisePacker 2.0 modules
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correctly.
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Case 3: Laxity/UNIC modules
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UNIC modules can have loop start specified in 16 bit words or in 32 bit
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words [4]. Use XMP_FLAGS_FIXLOOP to set this value to 16 bit words.
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References:
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[1] Michael Schwendt (Sat, 24 Oct 1998 22:41:21 +0000)
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"(...) all Soundtracker derivatives, including Ultimate Soundtracker,
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Soundtracker v1.0 to v4.0 and V to IX, Master Soundtracker 1.0,
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D.O.C-Soundtracker v2.0 to v2.3, use repeat_start in bytes (!).
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Hence MOD players should default to repeat_start in bytes. The first
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Soundtrackers to use repeat_start in words were Soundtracker v2.4
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(Spreadpoint), Noisetracker, and Protracker."
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[2] "Ultimate Soundtracker module format description", v0.1, by Michael
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Schwendt, lines 28--31: "Years later people without knowledge of the
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incompatibility between the original Soundtracker module format and
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successors like Soundtracker 2.4 or Protracker damaged modules by
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converting them to Protracker format."
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[3] "Amiga MOD packers described", version 4.1 (13/06/98), written by
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Sylvain Chipaux (Asle/ReDoX).
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[4] "Amiga MOD packers described", version 4.1 (13/06/98), written by
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Sylvain Chipaux (Asle/ReDoX). "About this loop start /4 or /2, I
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cannot tell for sure because I've encountered both cases: 'Guardian
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dragon' (/2) and 'Guardian dragon II' (/4).
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