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add automatic YUVA/ARGB conversion during WebPEncode()

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Adds new methods WebPPictureARGBToYUVA() and WebPPictureYUVAToARGB()
Depending on the value of picture->use_argb_input,
the main call WebPEncode() will convert appropriately.
Note that both conversions are lossy, so it's recommended to:
* use YUVA input for lossy compression (picture->use_argb_input=0)
* use ARGB input for lossless compression (picture->use_argb_input=1)

Change-Id: I8269d607723ee8a1136b9f4999f7ff4e657bbb04
This commit is contained in:
Pascal Massimino
2012-06-28 00:34:23 -07:00
parent 802e012a18
commit fcc69923b9
5 changed files with 378 additions and 137 deletions
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7
src/dsp/dsp.h
View File

@ -145,13 +145,13 @@ void VP8DspInit(void);
#define FANCY_UPSAMPLING // undefined to remove fancy upsampling support
#ifdef FANCY_UPSAMPLING
typedef void (*WebPUpsampleLinePairFunc)(
const uint8_t* top_y, const uint8_t* bottom_y,
const uint8_t* top_u, const uint8_t* top_v,
const uint8_t* cur_u, const uint8_t* cur_v,
uint8_t* top_dst, uint8_t* bottom_dst, int len);
#ifdef FANCY_UPSAMPLING
// Fancy upsampling functions to convert YUV to RGB(A) modes
extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
@ -169,6 +169,11 @@ typedef void (*WebPSampleLinePairFunc)(
extern const WebPSampleLinePairFunc WebPSamplers[/* MODE_LAST */];
// General function for converting two lines of ARGB or RGBA.
// 'alpha_is_last' should be true if 0xff000000 is stored in memory as
// as 0x00, 0x00, 0x00, 0xff (little endian).
WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last);
// YUV444->RGB converters
typedef void (*WebPYUV444Converter)(const uint8_t* y,
const uint8_t* u, const uint8_t* v,

42
src/dsp/upsampling.c
View File

@ -156,6 +156,48 @@ const WebPSampleLinePairFunc WebPSamplers[MODE_LAST] = {
SampleRgba4444LinePair // MODE_rgbA_4444
};
//------------------------------------------------------------------------------
#if !defined(FANCY_UPSAMPLING)
#define DUAL_SAMPLE_FUNC(FUNC_NAME, FUNC) \
static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bot_y, \
const uint8_t* top_u, const uint8_t* top_v, \
const uint8_t* bot_u, const uint8_t* bot_v, \
uint8_t* top_dst, uint8_t* bot_dst, int len) { \
const int half_len = len >> 1; \
int x; \
if (top_dst != NULL) { \
for (x = 0; x < half_len; ++x) { \
FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x + 0); \
FUNC(top_y[2 * x + 1], top_u[x], top_v[x], top_dst + 8 * x + 4); \
} \
if (len & 1) FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x); \
} \
if (bot_dst != NULL) { \
for (x = 0; x < half_len; ++x) { \
FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x + 0); \
FUNC(bot_y[2 * x + 1], bot_u[x], bot_v[x], bot_dst + 8 * x + 4); \
} \
if (len & 1) FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x); \
} \
}
DUAL_SAMPLE_FUNC(DualLineSamplerBGRA, VP8YuvToBgra)
DUAL_SAMPLE_FUNC(DualLineSamplerARGB, VP8YuvToArgb)
#undef DUAL_SAMPLE_FUNC
#endif // !FANCY_UPSAMPLING
WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last) {
WebPInitUpsamplers();
VP8YUVInit();
#ifdef FANCY_UPSAMPLING
return WebPUpsamplers[alpha_is_last ? MODE_BGRA : MODE_ARGB];
#else
return (alpha_is_last ? DualLineSamplerBGRA : DualLineSamplerARGB);
#endif
}
//------------------------------------------------------------------------------
// YUV444 converter