From 1101fcb3e61634f1be92e1b9ba9fad5a11b8554a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 16 Jan 2014 12:16:39 +0100 Subject: Add the 'rle' zstrategy --- erts/doc/src/zlib.xml | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) (limited to 'erts/doc/src/zlib.xml') diff --git a/erts/doc/src/zlib.xml b/erts/doc/src/zlib.xml index afc597b729..11a7437f5a 100644 --- a/erts/doc/src/zlib.xml +++ b/erts/doc/src/zlib.xml @@ -161,20 +161,22 @@ list_to_binary([Compressed|Last]) state. MemLevel=1 uses minimum memory but is slow and reduces compression ratio; MemLevel=9 uses maximum memory for optimal speed. The default value is 8.

-

The Strategy parameter is used to tune the - compression algorithm. Use the value default for - normal data, filtered for data produced by a filter - (or predictor), or huffman_only to force Huffman - encoding only (no string match). Filtered data consists - mostly of small values with a somewhat random - distribution. In this case, the compression algorithm is - tuned to compress them better. The effect of - filteredis to force more Huffman coding and less - string matching; it is somewhat intermediate between - default and huffman_only. The Strategy - parameter only affects the compression ratio but not the - correctness of the compressed output even if it is not set - appropriately.

+

The Strategy parameter is used to tune + the compression algorithm. Use the value default for + normal data, filtered for data produced by a filter (or + predictor), huffman_only to force Huffman encoding + only (no string match), or rle to limit match + distances to one (run-length encoding). Filtered data + consists mostly of small values with a somewhat random + distribution. In this case, the compression algorithm is tuned + to compress them better. The effect of filteredis to + force more Huffman coding and less string matching; it is + somewhat intermediate between default and + huffman_only. rle is designed to be almost as + fast as huffman_only, but give better compression for PNG + image data. The Strategy parameter only + affects the compression ratio but not the correctness of the + compressed output even if it is not set appropriately.

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