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authorYann Collet <yann.collet.73@gmail.com>2015-05-06 19:57:35 (GMT)
committerYann Collet <yann.collet.73@gmail.com>2015-05-06 19:57:35 (GMT)
commitfdd0029c3778768d0e8a80ce238d981f946c8b78 (patch)
tree5b2236b59cd0e42e3365b0765041a25c85519b39
parent672bfdebd0975289dbbdecabeeda9fabb499475a (diff)
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minor parsing update
-rw-r--r--lz4_Block_format.md22
1 files changed, 12 insertions, 10 deletions
diff --git a/lz4_Block_format.md b/lz4_Block_format.md
index b933a6a..a120a0b 100644
--- a/lz4_Block_format.md
+++ b/lz4_Block_format.md
@@ -45,17 +45,20 @@ There can be any number of bytes following the token. There is no "size limit".
(Side note : this is why a not-compressible input block is expanded by 0.4%).
Example 1 : A length of 48 will be represented as :
-- 15 : value for the 4-bits High field
-- 33 : (=48-15) remaining length to reach 48
+
+ - 15 : value for the 4-bits High field
+ - 33 : (=48-15) remaining length to reach 48
Example 2 : A length of 280 will be represented as :
-- 15 : value for the 4-bits High field
-- 255 : following byte is maxed, since 280-15 >= 255
-- 10 : (=280 - 15 - 255) ) remaining length to reach 280
+
+ - 15 : value for the 4-bits High field
+ - 255 : following byte is maxed, since 280-15 >= 255
+ - 10 : (=280 - 15 - 255) ) remaining length to reach 280
Example 3 : A length of 15 will be represented as :
-- 15 : value for the 4-bits High field
-- 0 : (=15-15) yes, the zero must be output
+
+ - 15 : value for the 4-bits High field
+ - 0 : (=15-15) yes, the zero must be output
Following the token and optional length bytes, are the literals themselves.
They are exactly as numerous as previously decoded (length of literals).
@@ -84,7 +87,7 @@ we output additional bytes, one at a time, with values ranging from 0 to 255.
They are added to total to provide the final match length.
A 255 value means there is another byte to read and add.
There is no limit to the number of optional bytes that can be output this way.
-(This points towards a maximum achievable compression ratio of ~250).
+(This points towards a maximum achievable compression ratio of about 250).
With the offset and the matchlength,
the decoder can now proceed to copy the data from the already decoded buffer.
@@ -98,8 +101,7 @@ There are specific parsing rules to respect in order to remain compatible
with assumptions made by the decoder :
1. The last 5 bytes are always literals
-2. The last match must start at least 12 bytes before end of block.
-
+2. The last match must start at least 12 bytes before end of block.
Consequently, a block with less than 13 bytes cannot be compressed.
These rules are in place to ensure that the decoder