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Unify the API between VP8BitWriter and VP8LBitWriter

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BitReader will be next...

Change-Id: Icd9e7ab2e3890131e664c0523627d9b8c5399a74
This commit is contained in:
Pascal Massimino
2014-10-23 15:35:16 +02:00
parent f7ada560ce
commit 5b90d8fe42
6 changed files with 84 additions and 83 deletions
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19
src/utils/bit_writer.c
View File

@ -140,19 +140,20 @@ int VP8PutBitUniform(VP8BitWriter* const bw, int bit) {
return bit;
}
void VP8PutValue(VP8BitWriter* const bw, int value, int nb_bits) {
int mask;
for (mask = 1 << (nb_bits - 1); mask; mask >>= 1)
void VP8PutBits(VP8BitWriter* const bw, uint32_t value, int nb_bits) {
uint32_t mask;
assert(nb_bits > 0 && nb_bits < 32);
for (mask = 1u << (nb_bits - 1); mask; mask >>= 1)
VP8PutBitUniform(bw, value & mask);
}
void VP8PutSignedValue(VP8BitWriter* const bw, int value, int nb_bits) {
void VP8PutSignedBits(VP8BitWriter* const bw, int value, int nb_bits) {
if (!VP8PutBitUniform(bw, value != 0))
return;
if (value < 0) {
VP8PutValue(bw, ((-value) << 1) | 1, nb_bits + 1);
VP8PutBits(bw, ((-value) << 1) | 1, nb_bits + 1);
} else {
VP8PutValue(bw, value << 1, nb_bits + 1);
VP8PutBits(bw, value << 1, nb_bits + 1);
}
}
@ -171,7 +172,7 @@ int VP8BitWriterInit(VP8BitWriter* const bw, size_t expected_size) {
}
uint8_t* VP8BitWriterFinish(VP8BitWriter* const bw) {
VP8PutValue(bw, 0, 9 - bw->nb_bits_);
VP8PutBits(bw, 0, 9 - bw->nb_bits_);
bw->nb_bits_ = 0; // pad with zeroes
Flush(bw);
return bw->buf_;
@ -242,14 +243,14 @@ int VP8LBitWriterInit(VP8LBitWriter* const bw, size_t expected_size) {
return VP8LBitWriterResize(bw, expected_size);
}
void VP8LBitWriterDestroy(VP8LBitWriter* const bw) {
void VP8LBitWriterWipeOut(VP8LBitWriter* const bw) {
if (bw != NULL) {
WebPSafeFree(bw->buf_);
memset(bw, 0, sizeof(*bw));
}
}
void VP8LWriteBits(VP8LBitWriter* const bw, int n_bits, uint32_t bits) {
void VP8LPutBits(VP8LBitWriter* const bw, uint32_t bits, int n_bits) {
assert(n_bits <= 32);
// That's the max we can handle:
assert(bw->used_ + n_bits <= 2 * VP8L_WRITER_MAX_BITS);

16
src/utils/bit_writer.h
View File

@ -45,8 +45,8 @@ void VP8BitWriterWipeOut(VP8BitWriter* const bw);
int VP8PutBit(VP8BitWriter* const bw, int bit, int prob);
int VP8PutBitUniform(VP8BitWriter* const bw, int bit);
void VP8PutValue(VP8BitWriter* const bw, int value, int nb_bits);
void VP8PutSignedValue(VP8BitWriter* const bw, int value, int nb_bits);
void VP8PutBits(VP8BitWriter* const bw, uint32_t value, int nb_bits);
void VP8PutSignedBits(VP8BitWriter* const bw, int value, int nb_bits);
// Appends some bytes to the internal buffer. Data is copied.
int VP8BitWriterAppend(VP8BitWriter* const bw,
@ -97,19 +97,19 @@ static WEBP_INLINE size_t VP8LBitWriterNumBytes(VP8LBitWriter* const bw) {
return (bw->cur_ - bw->buf_) + ((bw->used_ + 7) >> 3);
}
uint8_t* VP8LBitWriterFinish(VP8LBitWriter* const bw);
// Returns 0 in case of memory allocation error.
// Returns false in case of memory allocation error.
int VP8LBitWriterInit(VP8LBitWriter* const bw, size_t expected_size);
void VP8LBitWriterDestroy(VP8LBitWriter* const bw);
// Finalize the bitstream coding. Returns a pointer to the internal buffer.
uint8_t* VP8LBitWriterFinish(VP8LBitWriter* const bw);
// Release any pending memory and zeroes the object.
void VP8LBitWriterWipeOut(VP8LBitWriter* const bw);
// 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);
void VP8LPutBits(VP8LBitWriter* const bw, uint32_t bits, int n_bits);
//------------------------------------------------------------------------------