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libfreerdp-rfx: increase decoding bitmap number precision.

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This commit is contained in:
Vic Lee 2011-09-03 22:28:49 +08:00
parent bfaff0448d
commit 9feff5da7c
3 changed files with 49 additions and 26 deletions
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23
libfreerdp-rfx/rfx_decode.c
View File

@ -86,18 +86,31 @@ void rfx_decode_ycbcr_to_rgb(sint16* y_r_buf, sint16* cb_g_buf, sint16* cr_b_buf
{
sint16 y, cb, cr;
sint16 r, g, b;
int i;
/**
* The decoded YCbCr coeffectients are represented as 11.5 fixed-point numbers:
*
* 1 sign bit + 10 integer bits + 5 fractional bits
*
* However only 7 integer bits will be actually used since the value range is [-128.0, 127.0].
* In other words, the decoded coeffectients is scaled by << 5 when intepreted as sint16.
* It was scaled in the first RLGR decoding phase, so we must scale it back here.
*/
for (i = 0; i < 4096; i++)
{
y = y_r_buf[i] + 128;
y = (y_r_buf[i] >> 5) + 128;
cb = cb_g_buf[i];
cr = cr_b_buf[i];
r = (y + cr + (cr >> 2) + (cr >> 3) + (cr >> 5));
/* 1.403 >> 5 = 0.000010110011100(b) */
r = y + ((cr >> 5) + (cr >> 7) + (cr >> 8) + (cr >> 11) + (cr >> 12) + (cr >> 13));
y_r_buf[i] = MINMAX(r, 0, 255);
g = (y - ((cb >> 2) + (cb >> 4) + (cb >> 5)) - ((cr >> 1) + (cr >> 3) + (cr >> 4) + (cr >> 5)));
/* 0.344 >> 5 = 0.000000101100000(b), 0.714 >> 5 = 0.000001011011011(b) */
g = y - ((cb >> 7) + (cb >> 9) + (cb >> 10)) -
((cr >> 6) + (cr >> 8) + (cr >> 9) + (cr >> 11) + (cr >> 12) + (cr >> 13));
cb_g_buf[i] = MINMAX(g, 0, 255);
b = (y + cb + (cb >> 1) + (cb >> 2) + (cb >> 6));
/* 1.77 >> 5 = 0.000011100010100(b) */
b = y + ((cb >> 5) + (cb >> 6) + (cb >> 7) + (cb >> 11) + (cb >> 13));
cr_b_buf[i] = MINMAX(b, 0, 255);
}
}

3
libfreerdp-rfx/rfx_rlgr.c
View File

@ -42,10 +42,11 @@
#define GetBits(nBits) rfx_bitstream_get_bits(bs, nBits)
/* From current output pointer, write "value", check and update buffer_size */
/* The value is represented as 11.5 fixed-point number */
#define WriteValue(value) \
{ \
if (buffer_size > 0) \
*dst++ = (value); \
*dst++ = ((value) << 5); \
buffer_size--; \
}

49
libfreerdp-rfx/sse2/rfx_sse2.c
View File

@ -68,40 +68,49 @@ static void rfx_decode_ycbcr_to_rgb_sse2(sint16* y_r_buffer, sint16* cb_g_buffer
}
for (i = 0; i < (4096 * sizeof(sint16) / sizeof(__m128i)); i++)
{
/* y = y_r_buf[i] + 128; */
/* y = (y_r_buf[i] >> 5) + 128; */
y = _mm_load_si128(&y_r_buf[i]);
y = _mm_add_epi16(y, _mm_set1_epi16(128));
y = _mm_add_epi16(_mm_srai_epi16(y, 5), _mm_set1_epi16(128));
/* cr = cr_b_buf[i]; */
cr = _mm_load_si128(&cr_b_buf[i]);
/* r = between(y + cr + (cr >> 2) + (cr >> 3) + (cr >> 5), 0, 255); */
r = _mm_add_epi16(y, cr);
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 2));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 3));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 5));
/* r = y + ((cr >> 5) + (cr >> 7) + (cr >> 8) + (cr >> 11) + (cr >> 12) + (cr >> 13)); */
/* y_r_buf[i] = MINMAX(r, 0, 255); */
r = _mm_add_epi16(y, _mm_srai_epi16(cr, 5));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 7));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 8));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 11));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 12));
r = _mm_add_epi16(r, _mm_srai_epi16(cr, 13));
_mm_between_epi16(r, zero, max);
_mm_store_si128(&y_r_buf[i], r);
/* cb = cb_g_buf[i]; */
cb = _mm_load_si128(&cb_g_buf[i]);
/* g = between(y - (cb >> 2) - (cb >> 4) - (cb >> 5) - (cr >> 1) - (cr >> 3) - (cr >> 4) - (cr >> 5), 0, 255); */
g = _mm_sub_epi16(y, _mm_srai_epi16(cb, 2));
g = _mm_sub_epi16(g, _mm_srai_epi16(cb, 4));
g = _mm_sub_epi16(g, _mm_srai_epi16(cb, 5));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 1));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 3));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 4));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 5));
/* g = y - ((cb >> 7) + (cb >> 9) + (cb >> 10)) -
((cr >> 6) + (cr >> 8) + (cr >> 9) + (cr >> 11) + (cr >> 12) + (cr >> 13)); */
/* cb_g_buf[i] = MINMAX(g, 0, 255); */
g = _mm_sub_epi16(y, _mm_srai_epi16(cb, 7));
g = _mm_sub_epi16(g, _mm_srai_epi16(cb, 9));
g = _mm_sub_epi16(g, _mm_srai_epi16(cb, 10));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 6));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 8));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 9));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 11));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 12));
g = _mm_sub_epi16(g, _mm_srai_epi16(cr, 13));
_mm_between_epi16(g, zero, max);
_mm_store_si128(&cb_g_buf[i], g);
_mm_store_si128(&cb_g_buf[i], g);
/* b = between(y + cb + (cb >> 1) + (cb >> 2) + (cb >> 6), 0, 255); */
b = _mm_add_epi16(y, cb);
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 1));
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 2));
/* b = y + ((cb >> 5) + (cb >> 6) + (cb >> 7) + (cb >> 11) + (cb >> 13)); */
/* cr_b_buf[i] = MINMAX(b, 0, 255); */
b = _mm_add_epi16(y, _mm_srai_epi16(cb, 5));
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 6));
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 7));
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 11));
b = _mm_add_epi16(b, _mm_srai_epi16(cb, 13));
_mm_between_epi16(b, zero, max);
_mm_store_si128(&cr_b_buf[i], b);
}