diff options
Diffstat (limited to 'drivers/webp/enc/histogram.h')
| -rw-r--r-- | drivers/webp/enc/histogram.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/webp/enc/histogram.h b/drivers/webp/enc/histogram.h index 72f045793a..59de42b33e 100644 --- a/drivers/webp/enc/histogram.h +++ b/drivers/webp/enc/histogram.h @@ -24,6 +24,9 @@ extern "C" { #endif +// Not a trivial literal symbol. +#define VP8L_NON_TRIVIAL_SYM (0xffffffff) + // A simple container for histograms of data. typedef struct { // literal_ contains green literal, palette-code and @@ -103,6 +106,16 @@ int VP8LGetHistoImageSymbols(int xsize, int ysize, VP8LHistogramSet* const tmp_histos, uint16_t* const histogram_symbols); +// Returns the entropy for the symbols in the input array. +// Also sets trivial_symbol to the code value, if the array has only one code +// value. Otherwise, set it to VP8L_NON_TRIVIAL_SYM. +double VP8LBitsEntropy(const uint32_t* const array, int n, + uint32_t* const trivial_symbol); + +// Estimate how many bits the combined entropy of literals and distance +// approximately maps to. +double VP8LHistogramEstimateBits(const VP8LHistogram* const p); + #ifdef __cplusplus } #endif |