dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2024-12-26 13:48:21 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

add VP8EstimateTokenSize()

Browse Source 
estimates final size of coded tokens given a set of probabilities

Change-Id: Ia5a459422557d98b78b3cd8e1a88cb30835825b6
This commit is contained in:
skal 2013-09-11 10:08:49 +02:00
parent 10fddf53bb
commit b7d4e04255
2 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
src/enc/token.c
View File

@ -20,6 +20,7 @@
#include <stdlib.h>
#include <string.h>
#include "./cost.h"
#include "./vp8enci.h"
#if defined(__cplusplus) || defined(c_plusplus)
@ -238,6 +239,29 @@ int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw,
return 1;
}
// Size estimation
size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas) {
size_t size = 0;
const VP8Tokens* p = b->pages_;
if (b->error_) return 0;
while (p != NULL) {
const VP8Tokens* const next = p->next_;
const int N = (next == NULL) ? b->left_ : 0;
int n = MAX_NUM_TOKEN;
while (n-- > N) {
const uint16_t token = p->tokens_[n];
const int bit = token & (1 << 15);
if (token & FIXED_PROBA_BIT) {
size += VP8BitCost(bit, token & 0xffu);
} else {
size += VP8BitCost(bit, probas[token & 0x3fffu]);
}
}
p = next;
}
return size;
}
//------------------------------------------------------------------------------
#else // DISABLE_TOKEN_BUFFER

3
src/enc/vp8enci.h
View File

@ -379,6 +379,9 @@ int VP8RecordCoeffTokens(int ctx, int coeff_type, int first, int last,
const int16_t* const coeffs,
VP8TBuffer* const tokens);
// Estimate the final coded size given a set of 'probas'.
size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas);
// unused for now
void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats);