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Support decoding upto given row in DECODE_DATA_FUNC

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This is in preparation for supporting Intertwined decoding of RGB and
alpha.

Change-Id: Ie1905d1212f4a00718a64dca020be3f4b1b870ec
This commit is contained in:
Urvang Joshi 2013-06-11 16:00:58 -07:00
parent 520f005f85
commit 3fa595a571
2 changed files with 23 additions and 13 deletions
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33
src/dec/vp8l.c
View File

@ -685,22 +685,26 @@ static void ProcessRows(VP8LDecoder* const dec, int row) {
#define DECODE_DATA_FUNC(FUNC_NAME, TYPE, STORE_PIXEL) \
static int FUNC_NAME(VP8LDecoder* const dec, TYPE* const data, int width, \
int height, ProcessRowsFunc process_func) { \
int height, int last_row, \
ProcessRowsFunc process_func) { \
int ok = 1; \
int col = 0, row = 0; \
int row = dec->last_pixel_ / width; \
int col = dec->last_pixel_ % width; \
VP8LBitReader* const br = &dec->br_; \
VP8LMetadata* const hdr = &dec->hdr_; \
HTreeGroup* htree_group = hdr->htree_groups_; \
TYPE* src = data; \
TYPE* last_cached = data; \
TYPE* const src_end = data + width * height; \
HTreeGroup* htree_group = GetHtreeGroupForPos(hdr, col, row); \
TYPE* src = data + dec->last_pixel_; \
TYPE* last_cached = src; \
TYPE* const src_end = data + width * height; /* End of data */ \
TYPE* const src_last = data + width * last_row; /* Last pixel to decode */ \
const int len_code_limit = NUM_LITERAL_CODES + NUM_LENGTH_CODES; \
const int color_cache_limit = len_code_limit + hdr->color_cache_size_; \
VP8LColorCache* const color_cache = \
(hdr->color_cache_size_ > 0) ? &hdr->color_cache_ : NULL; \
const int mask = hdr->huffman_mask_; \
assert(htree_group != NULL); \
while (!br->eos_ && src < src_end) { \
assert(src_last <= src_end); \
while (!br->eos_ && src < src_last) { \
int code; \
/* Only update when changing tile. Note we could use this test: */ \
/* if "((((prev_col ^ col) | prev_row ^ row)) > mask)" -> tile changed */ \
@ -788,8 +792,9 @@ End: \
ok = 0; \
dec->status_ = \
(!br->eos_) ? VP8_STATUS_BITSTREAM_ERROR : VP8_STATUS_SUSPENDED; \
} else if (src == src_end) { \
dec->state_ = READ_DATA; \
} else { \
dec->last_pixel_ = src - data; \
if (src == src_end) dec->state_ = READ_DATA; \
} \
return ok; \
}
@ -1030,7 +1035,8 @@ static int DecodeImageStream(int xsize, int ysize,
}
// Use the Huffman trees to decode the LZ77 encoded data.
ok = DecodeImageData(dec, data, transform_xsize, transform_ysize, NULL);
ok = DecodeImageData(dec, data, transform_xsize, transform_ysize,
transform_ysize, NULL);
ok = ok && !br->error_;
End:
@ -1052,6 +1058,7 @@ static int DecodeImageStream(int xsize, int ysize,
assert(data == NULL);
assert(is_level0);
}
dec->last_pixel_ = 0; // Reset for future DECODE_DATA_FUNC() calls.
if (!is_level0) ClearMetadata(hdr); // Clean up temporary data behind.
}
return ok;
@ -1157,9 +1164,9 @@ int VP8LDecodeAlphaImageStream(int width, int height, const uint8_t* const data,
dec->action_ = READ_DATA;
ok = (bytes_per_pixel == sizeof(uint8_t)) ?
DecodeAlphaData(dec, (uint8_t*)dec->pixels_, dec->width_, dec->height_,
ExtractPalettedAlphaRows) :
dec->height_, ExtractPalettedAlphaRows) :
DecodeImageData(dec, dec->pixels_, dec->width_, dec->height_,
ExtractAlphaRows);
dec->height_, ExtractAlphaRows);
Err:
VP8LDelete(dec);
@ -1226,7 +1233,7 @@ int VP8LDecodeImage(VP8LDecoder* const dec) {
// Decode.
dec->action_ = READ_DATA;
if (!DecodeImageData(dec, dec->pixels_, dec->width_, dec->height_,
ProcessRows)) {
dec->height_, ProcessRows)) {
goto Err;
}

3
src/dec/vp8li.h
View File

@ -74,6 +74,9 @@ typedef struct {
int width_;
int height_;
int last_row_; // last input row decoded so far.
int last_pixel_; // last pixel decoded so far. However, it may
// not be transformed, scaled and
// color-converted yet.
int last_out_row_; // last row output so far.
VP8LMetadata hdr_;