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make VP8LSetBitPos() set br->eos_ flag

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ReadSymbol() finishes with a VP8LSetBitPos() call only and could miss an eos_ during the decode loop.

Things are faster because of inlining too.

(cherry picked from commit d3242aee16)

Change-Id: I2d2a275f38834ba005bc767d45c5de72d032103e
This commit is contained in:
Pascal Massimino
2014-09-06 08:40:20 +02:00
committed by James Zern
parent 2e4312b14f
commit 3ab0a377d2
3 changed files with 40 additions and 36 deletions
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17
src/utils/bit_reader.h
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@ -107,6 +107,9 @@ int32_t VP8GetSignedValue(VP8BitReader* const br, int num_bits);
// maximum number of bits (inclusive) the bit-reader can handle:
#define VP8L_MAX_NUM_BIT_READ 24
#define VP8L_LBITS 64 // Number of bits prefetched.
#define VP8L_WBITS 32 // Minimum number of bytes ready after VP8LFillBitWindow.
typedef uint64_t vp8l_val_t; // right now, this bit-reader can only use 64bit.
typedef struct {
@ -138,14 +141,26 @@ static WEBP_INLINE uint32_t VP8LPrefetchBits(VP8LBitReader* const br) {
return (uint32_t)(br->val_ >> br->bit_pos_);
}
// Returns true if there was an attempt at reading bit past the end of
// the buffer. Doesn't set br->eos_ flag.
static WEBP_INLINE int VP8LIsEndOfStream(const VP8LBitReader* const br) {
assert(br->pos_ <= br->len_);
return (br->pos_ == br->len_) && (br->bit_pos_ > VP8L_LBITS);
}
// For jumping over a number of bits in the bit stream when accessed with
// VP8LPrefetchBits and VP8LFillBitWindow.
static WEBP_INLINE void VP8LSetBitPos(VP8LBitReader* const br, int val) {
br->bit_pos_ = val;
br->eos_ = VP8LIsEndOfStream(br);
}
// Advances the read buffer by 4 bytes to make room for reading next 32 bits.
void VP8LFillBitWindow(VP8LBitReader* const br);
// Speed critical, but infrequent part of the code can be non-inligned.
extern void VP8LDoFillBitWindow(VP8LBitReader* const br);
static WEBP_INLINE void VP8LFillBitWindow(VP8LBitReader* const br) {
if (br->bit_pos_ >= VP8L_WBITS) VP8LDoFillBitWindow(br);
}
#ifdef __cplusplus
} // extern "C"