diff options
Diffstat (limited to 'src/3rdparty/libwebp/src/utils/bit_writer.h')
-rw-r--r-- | src/3rdparty/libwebp/src/utils/bit_writer.h | 55 |
1 files changed, 25 insertions, 30 deletions
diff --git a/src/3rdparty/libwebp/src/utils/bit_writer.h b/src/3rdparty/libwebp/src/utils/bit_writer.h index 89a9ead..c80d22a 100644 --- a/src/3rdparty/libwebp/src/utils/bit_writer.h +++ b/src/3rdparty/libwebp/src/utils/bit_writer.h @@ -68,51 +68,46 @@ static WEBP_INLINE size_t VP8BitWriterSize(const VP8BitWriter* const bw) { //------------------------------------------------------------------------------ // VP8LBitWriter -// TODO(vikasa): VP8LBitWriter is copied as-is from lossless code. There's scope -// of re-using VP8BitWriter. Will evaluate once basic lossless encoder is -// implemented. -typedef struct { - uint8_t* buf_; - size_t bit_pos_; - size_t max_bytes_; +#if defined(__x86_64__) || defined(_M_X64) // 64bit +typedef uint64_t vp8l_atype_t; // accumulator type +typedef uint32_t vp8l_wtype_t; // writing type +#define WSWAP HToLE32 +#else +typedef uint32_t vp8l_atype_t; +typedef uint16_t vp8l_wtype_t; +#define WSWAP HToLE16 +#endif - // After all bits are written, the caller must observe the state of - // error_. A value of 1 indicates that a memory allocation failure - // has happened during bit writing. A value of 0 indicates successful +typedef struct { + vp8l_atype_t bits_; // bit accumulator + int used_; // number of bits used in accumulator + uint8_t* buf_; // start of buffer + uint8_t* cur_; // current write position + uint8_t* end_; // end of buffer + + // After all bits are written (VP8LBitWriterFinish()), the caller must observe + // the state of error_. A value of 1 indicates that a memory allocation + // failure has happened during bit writing. A value of 0 indicates successful // writing of bits. int error_; } VP8LBitWriter; static WEBP_INLINE size_t VP8LBitWriterNumBytes(VP8LBitWriter* const bw) { - return (bw->bit_pos_ + 7) >> 3; + return (bw->cur_ - bw->buf_) + ((bw->used_ + 7) >> 3); } -static WEBP_INLINE uint8_t* VP8LBitWriterFinish(VP8LBitWriter* const bw) { - return bw->buf_; -} +uint8_t* VP8LBitWriterFinish(VP8LBitWriter* const bw); // Returns 0 in case of memory allocation error. int VP8LBitWriterInit(VP8LBitWriter* const bw, size_t expected_size); void VP8LBitWriterDestroy(VP8LBitWriter* const bw); -// This function writes bits into bytes in increasing addresses, and within -// a byte least-significant-bit first. -// -// The function can write up to 16 bits in one go with WriteBits -// Example: let's assume that 3 bits (Rs below) have been written already: -// -// BYTE-0 BYTE+1 BYTE+2 -// -// 0000 0RRR 0000 0000 0000 0000 -// -// Now, we could write 5 or less bits in MSB by just sifting by 3 -// and OR'ing to BYTE-0. -// -// For n bits, we take the last 5 bytes, OR that with high bits in BYTE-0, -// and locate the rest in BYTE+1 and BYTE+2. -// +// This function writes bits into bytes in increasing addresses (little endian), +// and within a byte least-significant-bit first. +// This function can write up to 32 bits in one go, but VP8LBitReader can only +// read 24 bits max (VP8L_MAX_NUM_BIT_READ). // VP8LBitWriter's error_ flag is set in case of memory allocation error. void VP8LWriteBits(VP8LBitWriter* const bw, int n_bits, uint32_t bits); |