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Rename PRE_VP8 state to WEBP_HEADER

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Also, rename state VP8_FRAME_HEADER to VP8_HEADER (to be consistent with
VP8L_HEADER).

Change-Id: Ief2d2f483e36d37f00d8d0db87026ad059f27327
This commit is contained in:
Urvang Joshi 2013-04-08 12:19:29 -07:00 committed by Gerrit Code Review
parent ead4d47859
commit a681b4f4e5
1 changed files with 12 additions and 10 deletions
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22
src/dec/idec.c
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@ -29,11 +29,13 @@ extern "C" {
//------------------------------------------------------------------------------
// Data structures for memory and states
// Decoding states. State normally flows like HEADER->PARTS0->DATA->DONE.
// Decoding states. State normally flows as:
// WEBP_HEADER->VP8_HEADER->VP8_PARTS0->VP8_DATA->DONE for a lossy image, and
// WEBP_HEADER->VP8L_HEADER->VP8L_DATA->DONE for a lossless image.
// If there is any error the decoder goes into state ERROR.
typedef enum {
STATE_PRE_VP8, // All data before that of the first VP8 chunk.
STATE_VP8_FRAME_HEADER, // For VP8 Frame header (within VP8 chunk).
STATE_WEBP_HEADER, // All the data before that of the VP8/VP8L chunk.
STATE_VP8_HEADER, // The VP8 Frame header (within the VP8 chunk).
STATE_VP8_PARTS0,
STATE_VP8_DATA,
STATE_VP8L_HEADER,
@ -100,7 +102,7 @@ static WEBP_INLINE size_t MemDataSize(const MemBuffer* mem) {
// Check if we need to preserve the compressed alpha data, as it may not have
// been decoded yet.
static int NeedCompressedAlpha(const WebPIDecoder* const idec) {
if (idec->state_ == STATE_PRE_VP8) {
if (idec->state_ == STATE_WEBP_HEADER) {
// We haven't parsed the headers yet, so we don't know whether the image is
// lossy or lossless. This also means that we haven't parsed the ALPH chunk.
return 0;
@ -109,7 +111,7 @@ static int NeedCompressedAlpha(const WebPIDecoder* const idec) {
return 0; // ALPH chunk is not present for lossless images.
} else {
const VP8Decoder* const dec = (VP8Decoder*)idec->dec_;
assert(dec != NULL); // Must be true as idec->state_ != STATE_PRE_VP8.
assert(dec != NULL); // Must be true as idec->state_ != STATE_WEBP_HEADER.
return (dec->alpha_data_ != NULL) && !dec->is_alpha_decoded_;
}
}
@ -317,7 +319,7 @@ static VP8StatusCode DecodeWebPHeaders(WebPIDecoder* const idec) {
#endif
dec->alpha_data_ = headers.alpha_data;
dec->alpha_data_size_ = headers.alpha_data_size;
ChangeState(idec, STATE_VP8_FRAME_HEADER, headers.offset);
ChangeState(idec, STATE_VP8_HEADER, headers.offset);
} else {
VP8LDecoder* const dec = VP8LNew();
if (dec == NULL) {
@ -530,14 +532,14 @@ static VP8StatusCode DecodeVP8LData(WebPIDecoder* const idec) {
static VP8StatusCode IDecode(WebPIDecoder* idec) {
VP8StatusCode status = VP8_STATUS_SUSPENDED;
if (idec->state_ == STATE_PRE_VP8) {
if (idec->state_ == STATE_WEBP_HEADER) {
status = DecodeWebPHeaders(idec);
} else {
if (idec->dec_ == NULL) {
return VP8_STATUS_SUSPENDED; // can't continue if we have no decoder.
}
}
if (idec->state_ == STATE_VP8_FRAME_HEADER) {
if (idec->state_ == STATE_VP8_HEADER) {
status = DecodeVP8FrameHeader(idec);
}
if (idec->state_ == STATE_VP8_PARTS0) {
@ -564,7 +566,7 @@ WebPIDecoder* WebPINewDecoder(WebPDecBuffer* output_buffer) {
return NULL;
}
idec->state_ = STATE_PRE_VP8;
idec->state_ = STATE_WEBP_HEADER;
idec->chunk_size_ = 0;
InitMemBuffer(&idec->mem_);
@ -821,7 +823,7 @@ int WebPISetIOHooks(WebPIDecoder* const idec,
VP8IoSetupHook setup,
VP8IoTeardownHook teardown,
void* user_data) {
if (idec == NULL || idec->state_ > STATE_PRE_VP8) {
if (idec == NULL || idec->state_ > STATE_WEBP_HEADER) {
return 0;
}