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make the bundling work in a tmp buffer

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This avoids modifying the source picture.

Change-Id: I5b472859cda17fd3236a9e0fbedbb68977e09f85
This commit is contained in:
skal 2012-11-15 09:05:25 +01:00
parent a7305c2ef0
commit 0f923c3ffd
1 changed files with 37 additions and 36 deletions
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73
src/enc/vp8l.c
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@ -813,30 +813,24 @@ static WebPEncodingError AllocateTransformBuffer(VP8LEncoder* const enc,
return err;
}
// Bundles multiple (2, 4 or 8) pixels into a single pixel.
// Returns the new xsize.
static void BundleColorMap(const WebPPicture* const pic,
int xbits, uint32_t* bundled_argb, int xs) {
int y;
const int bit_depth = 1 << (3 - xbits);
uint32_t code = 0;
const uint32_t* argb = pic->argb;
const int width = pic->width;
const int height = pic->height;
for (y = 0; y < height; ++y) {
int x;
// Bundles multiple (1, 2, 4 or 8) pixels into a single pixel.
static void BundleColorMap(const uint8_t* const row, int width,
int xbits, uint32_t* const dst) {
int x;
if (xbits > 0) {
const int bit_depth = 1 << (3 - xbits);
const int mask = (1 << xbits) - 1;
uint32_t code = 0xff000000;
for (x = 0; x < width; ++x) {
const int mask = (1 << xbits) - 1;
const int xsub = x & mask;
if (xsub == 0) {
code = 0;
code = 0xff000000;
}
// TODO(vikasa): simplify the bundling logic.
code |= (argb[x] & 0xff00) << (bit_depth * xsub);
bundled_argb[y * xs + (x >> xbits)] = 0xff000000 | code;
code |= row[x] << (8 + bit_depth * xsub);
dst[x >> xbits] = code;
}
argb += pic->argb_stride;
} else {
for (x = 0; x < width; ++x) dst[x] = 0xff000000 | (row[x] << 8);
}
}
@ -848,24 +842,43 @@ static WebPEncodingError ApplyPalette(VP8LBitWriter* const bw,
WebPEncodingError err = VP8_ENC_OK;
int i, x, y;
const WebPPicture* const pic = enc->pic_;
uint32_t* argb = pic->argb;
uint32_t* src = pic->argb;
uint32_t* dst;
const int width = pic->width;
const int height = pic->height;
uint32_t* const palette = enc->palette_;
const int palette_size = enc->palette_size_;
uint8_t* row = NULL;
int xbits;
// Replace each input pixel by corresponding palette index.
// This is done line by line.
if (palette_size <= 4) {
xbits = (palette_size <= 2) ? 3 : 2;
} else {
xbits = (palette_size <= 16) ? 1 : 0;
}
err = AllocateTransformBuffer(enc, VP8LSubSampleSize(width, xbits), height);
if (err != VP8_ENC_OK) goto Error;
dst = enc->argb_;
row = WebPSafeMalloc((uint64_t)width, sizeof(*row));
if (row == NULL) return VP8_ENC_ERROR_OUT_OF_MEMORY;
for (y = 0; y < height; ++y) {
for (x = 0; x < width; ++x) {
const uint32_t pix = argb[x];
const uint32_t pix = src[x];
for (i = 0; i < palette_size; ++i) {
if (pix == palette[i]) {
argb[x] = 0xff000000u | (i << 8);
row[x] = i;
break;
}
}
}
argb += pic->argb_stride;
BundleColorMap(row, width, xbits, dst);
src += pic->argb_stride;
dst += enc->current_width_;
}
// Save palette to bitstream.
@ -881,20 +894,8 @@ static WebPEncodingError ApplyPalette(VP8LBitWriter* const bw,
goto Error;
}
if (palette_size <= 16) {
// Image can be packed (multiple pixels per uint32_t).
int xbits = 1;
if (palette_size <= 2) {
xbits = 3;
} else if (palette_size <= 4) {
xbits = 2;
}
err = AllocateTransformBuffer(enc, VP8LSubSampleSize(width, xbits), height);
if (err != VP8_ENC_OK) goto Error;
BundleColorMap(pic, xbits, enc->argb_, enc->current_width_);
}
Error:
free(row);
return err;
}