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fix bug with lossy-alpha output stride

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dec->width_ != final_width in case of Bundle transform!

thanks to Pepijn for spotting the problem

Change-Id: I08b451a32097dcbf23b73deabc8cc6a2d59f0119
This commit is contained in:
Pascal Massimino
2012-05-24 08:54:02 -07:00
parent e75dc80516
commit 3bde22d768
1 changed files with 6 additions and 4 deletions
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10
src/dec/vp8l.c
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@@ -945,16 +945,16 @@ static int AllocateARGBBuffers(VP8LDecoder* const dec, int final_width) {
static void ExtractAlphaRows(VP8LDecoder* const dec, int row) { static void ExtractAlphaRows(VP8LDecoder* const dec, int row) {
const int num_rows = row - dec->last_row_; const int num_rows = row - dec->last_row_;
const int cache_pixs = dec->width_ * num_rows; const uint32_t* const in = dec->argb_ + dec->width_ * dec->last_row_;
const int argb_offset = dec->width_ * dec->last_row_;
const uint32_t* const in = dec->argb_ + argb_offset;
if (num_rows <= 0) return; // Nothing to be done. if (num_rows <= 0) return; // Nothing to be done.
ApplyTransforms(dec, num_rows, in); ApplyTransforms(dec, num_rows, in);
// Extract alpha (which is stored in the green plane). // Extract alpha (which is stored in the green plane).
{ {
uint8_t* const dst = (uint8_t*)dec->io_->opaque + argb_offset; const int width = dec->io_->width; // the final width (!= dec->width_)
const int cache_pixs = width * num_rows;
uint8_t* const dst = (uint8_t*)dec->io_->opaque + width * dec->last_row_;
const uint32_t* const src = dec->argb_cache_; const uint32_t* const src = dec->argb_cache_;
int i; int i;
for (i = 0; i < cache_pixs; ++i) dst[i] = (src[i] >> 8) & 0xff; for (i = 0; i < cache_pixs; ++i) dst[i] = (src[i] >> 8) & 0xff;
@@ -977,6 +977,8 @@ int VP8LDecodeAlphaImageStream(int width, int height, const uint8_t* const data,
VP8InitIo(&io); VP8InitIo(&io);
WebPInitCustomIo(NULL, &io); // Just a sanity Init. io won't be used. WebPInitCustomIo(NULL, &io); // Just a sanity Init. io won't be used.
io.opaque = output; io.opaque = output;
io.width = width;
io.height = height;
dec->status_ = VP8_STATUS_OK; dec->status_ = VP8_STATUS_OK;
VP8LInitBitReader(&dec->br_, data, data_size); VP8LInitBitReader(&dec->br_, data, data_size);