Keep reference sample in struct member to start more loops from zero.

[platform/upstream/libaec.git] / README

diff --git a/README b/README
index 440e4be..dcfd003 100644 (file)
--- a/README
+++ b/README
@@ -11,7 +11,7 @@ supported, they can also be efficiently coded by grouping exponents
 and mantissa.
 
 Libaec implements Golomb Rice coding as defined in the Space Data
-System Standard document 121.0-B-2 [1], [2].
+System Standard documents 121.0-B-2 [1] and 120.0-G-2[2].
 
 
 **********************************************************************
@@ -94,7 +94,7 @@ rsi sets the reference sample interval. A large RSI will improve
 performance and efficiency. It will also increase memory requirements
 since internal buffering is based on RSI size. A smaller RSI may be
 desirable in situations where each RSI will be packetized and possible
-error propagation has to be minimized (e.g. on board a spacecraft[2]).
+error propagation has to be minimized.
 
 Flags:
 
@@ -113,6 +113,14 @@ architectures.
 
 AEC_DATA_3BYTE: the 24 bit input data is stored in three bytes.
 
+AEC_RESTRICTED: use a restricted set of code options. This option is
+only valid for bits_per_sample <= 4.
+
+AEC_PAD_RSI: assume that the encoded RSI is padded to the next byte
+boundary while decoding. The preprocessor macro ENABLE_RSI_PADDING
+needs to be defined while compiling for the encoder to honour this
+flag.
+
 Data size:
 
 Except for the AEC_DATA_3BYTE case for 24 bit data, the following
@@ -120,9 +128,9 @@ rules apply for deducing storage size from sample size
 (bits_per_sample):
 
 sample size   storage size
- 1 -  8 bit   1 byte
- 9 - 16 bit   2 bytes
-17 - 32 bit   4 bytes (also for 24bit if AEC_DATA_3BYTE is not set)
+ 1 -  8 bits  1 byte
+ 9 - 16 bits  2 bytes
+17 - 32 bits  4 bytes (also for 24bit if AEC_DATA_3BYTE is not set)
 
 If a sample requires less bits than the storage size provides, then
 you have to make sure that unused bits are not set. Libaec does not
@@ -206,6 +214,6 @@ http://public.ccsds.org/publications/archive/121x0b2.pdf
 
 [2] Consultative Committee for Space Data Systems. Lossless Data
 Compression.  Recommendation for Space Data System Standards, CCSDS
-120.0-G-2. Green Book. Issue 2. Washington, D.C.: CCSDS, December
-2006.
-http://public.ccsds.org/publications/archive/120x0g2.pdf
+120.0-G-3. Green Book. Issue 3. Washington, D.C.: CCSDS, April
+2013.
+http://public.ccsds.org/publications/archive/120x0g3.pdf