dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-16 13:59:51 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

Move ARGB->YUV functions from dec/vp8l.c to dsp/yuv.c

Browse Source 
also switch to using ExtractAlpha() instead of hard-coding the loop.

The ARGBToY/UV functions are rather easy to port to SSE2 / NEON.

Change-Id: I8f1346a9ca427a36ce2d6c848369ca7964d8b3c7
This commit is contained in:
Pascal Massimino
2015-10-27 02:37:45 -07:00
parent 469ba2cdfd
commit fa8927efe4
3 changed files with 100 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
src/dec/vp8l.c
View File

@ -19,6 +19,7 @@
#include "../dsp/dsp.h"
#include "../dsp/lossless.h"
#include "../dsp/yuv.h"
#include "../utils/endian_inl.h"
#include "../utils/huffman.h"
#include "../utils/utils.h"
@ -504,67 +505,29 @@ static int EmitRows(WEBP_CSP_MODE colorspace,
//------------------------------------------------------------------------------
// Export to YUVA
// TODO(skal): should be in yuv.c
static void ConvertToYUVA(const uint32_t* const src, int width, int y_pos,
const WebPDecBuffer* const output) {
const WebPYUVABuffer* const buf = &output->u.YUVA;
// first, the luma plane
{
int i;
uint8_t* const y = buf->y + y_pos * buf->y_stride;
for (i = 0; i < width; ++i) {
const uint32_t p = src[i];
y[i] = VP8RGBToY((p >> 16) & 0xff, (p >> 8) & 0xff, (p >> 0) & 0xff,
YUV_HALF);
}
}
WebPConvertARGBToY(src, buf->y + y_pos * buf->y_stride, width);
// then U/V planes
{
uint8_t* const u = buf->u + (y_pos >> 1) * buf->u_stride;
uint8_t* const v = buf->v + (y_pos >> 1) * buf->v_stride;
const int uv_width = width >> 1;
int i;
for (i = 0; i < uv_width; ++i) {
const uint32_t v0 = src[2 * i + 0];
const uint32_t v1 = src[2 * i + 1];
// VP8RGBToU/V expects four accumulated pixels. Hence we need to
// scale r/g/b value by a factor 2. We just shift v0/v1 one bit less.
const int r = ((v0 >> 15) & 0x1fe) + ((v1 >> 15) & 0x1fe);
const int g = ((v0 >> 7) & 0x1fe) + ((v1 >> 7) & 0x1fe);
const int b = ((v0 << 1) & 0x1fe) + ((v1 << 1) & 0x1fe);
if (!(y_pos & 1)) { // even lines: store values
u[i] = VP8RGBToU(r, g, b, YUV_HALF << 2);
v[i] = VP8RGBToV(r, g, b, YUV_HALF << 2);
} else { // odd lines: average with previous values
const int tmp_u = VP8RGBToU(r, g, b, YUV_HALF << 2);
const int tmp_v = VP8RGBToV(r, g, b, YUV_HALF << 2);
// Approximated average-of-four. But it's an acceptable diff.
u[i] = (u[i] + tmp_u + 1) >> 1;
v[i] = (v[i] + tmp_v + 1) >> 1;
}
}
if (width & 1) { // last pixel
const uint32_t v0 = src[2 * i + 0];
const int r = (v0 >> 14) & 0x3fc;
const int g = (v0 >> 6) & 0x3fc;
const int b = (v0 << 2) & 0x3fc;
if (!(y_pos & 1)) { // even lines
u[i] = VP8RGBToU(r, g, b, YUV_HALF << 2);
v[i] = VP8RGBToV(r, g, b, YUV_HALF << 2);
} else { // odd lines (note: we could just skip this)
const int tmp_u = VP8RGBToU(r, g, b, YUV_HALF << 2);
const int tmp_v = VP8RGBToV(r, g, b, YUV_HALF << 2);
u[i] = (u[i] + tmp_u + 1) >> 1;
v[i] = (v[i] + tmp_v + 1) >> 1;
}
}
// even lines: store values
// odd lines: average with previous values
WebPConvertARGBToUV(src, u, v, width, !(y_pos & 1));
}
// Lastly, store alpha if needed.
if (buf->a != NULL) {
int i;
uint8_t* const a = buf->a + y_pos * buf->a_stride;
for (i = 0; i < width; ++i) a[i] = (src[i] >> 24);
#if defined(WORDS_BIGENDIAN)
WebPExtractAlpha((uint8_t*)src + 0, 0, width, 1, a, 0);
#else
WebPExtractAlpha((uint8_t*)src + 3, 0, width, 1, a, 0);
#endif
}
}
@ -713,7 +676,7 @@ static void ProcessRows(VP8LDecoder* const dec, int row) {
// Nothing to output (this time).
} else {
const WebPDecBuffer* const output = dec->output_;
if (output->colorspace < MODE_YUV) { // convert to RGBA
if (WebPIsRGBMode(output->colorspace)) { // convert to RGBA
const WebPRGBABuffer* const buf = &output->u.RGBA;
uint8_t* const rgba = buf->rgba + dec->last_out_row_ * buf->stride;
const int num_rows_out = io->use_scaling ?
@ -1552,6 +1515,10 @@ int VP8LDecodeImage(VP8LDecoder* const dec) {
// need the alpha-multiply functions for premultiplied output or rescaling
WebPInitAlphaProcessing();
}
if (!WebPIsRGBMode(dec->output_->colorspace)) {
WebPInitConvertARGBToYUV();
if (dec->output_->u.YUVA.a != NULL) WebPInitAlphaProcessing();
}
if (dec->incremental_) {
if (dec->hdr_.color_cache_size_ > 0 &&
dec->hdr_.saved_color_cache_.colors_ == NULL) {