The branch, master has been updated
via 1d84ab331cb75a1c21d2705b24448b9971380697 (commit)
from 2b221fdb4a1bdc556225eb15688dc112b81f2246 (commit)
- Log -----------------------------------------------------------------
commit 1d84ab331cb75a1c21d2705b24448b9971380697
Author: averne <[email protected]>
AuthorDate: Sun Nov 2 20:23:28 2025 +0100
Commit: Lynne <[email protected]>
CommitDate: Tue Nov 25 17:54:56 2025 +0000
vulkan/prores: Adopt the same IDCT routine as the prores-raw hwaccel
The added rounding at the final output conforms
to the SMPTE document and reduces the deviation
against the software decoder.
diff --git a/libavcodec/vulkan/prores_idct.comp
b/libavcodec/vulkan/prores_idct.comp
index 4b39b3d8ae..05ba8e4967 100644
--- a/libavcodec/vulkan/prores_idct.comp
+++ b/libavcodec/vulkan/prores_idct.comp
@@ -37,47 +37,77 @@ void put_px(uint tex_idx, ivec2 pos, uint v)
#endif
}
+const float idct_8x8_scales[] = {
+ 0.353553390593274f, // cos(4 * pi/16) / 2
+ 0.490392640201615f, // cos(1 * pi/16) / 2
+ 0.461939766255643f, // cos(2 * pi/16) / 2
+ 0.415734806151273f, // cos(3 * pi/16) / 2
+ 0.353553390593274f, // cos(4 * pi/16) / 2
+ 0.277785116509801f, // cos(5 * pi/16) / 2
+ 0.191341716182545f, // cos(6 * pi/16) / 2
+ 0.097545161008064f, // cos(7 * pi/16) / 2
+};
+
/* 7.4 Inverse Transform */
void idct(uint block, uint offset, uint stride)
{
- float c0 = blocks[block][0*stride + offset];
- float c1 = blocks[block][1*stride + offset];
- float c2 = blocks[block][2*stride + offset];
- float c3 = blocks[block][3*stride + offset];
- float c4 = blocks[block][4*stride + offset];
- float c5 = blocks[block][5*stride + offset];
- float c6 = blocks[block][6*stride + offset];
- float c7 = blocks[block][7*stride + offset];
-
- float tmp1 = c6 * 1.4142134189605712891 + (c2 - c6);
- float tmp2 = c6 * 1.4142134189605712891 - (c2 - c6);
-
- float a1 = (c0 + c4) * 0.35355341434478759766 + tmp1 *
0.46193981170654296875;
- float a4 = (c0 + c4) * 0.35355341434478759766 - tmp1 *
0.46193981170654296875;
-
- float a3 = (c0 - c4) * 0.35355341434478759766 + tmp2 *
0.19134169816970825195;
- float a2 = (c0 - c4) * 0.35355341434478759766 - tmp2 *
0.19134169816970825195;
-
- float tmp3 = (c3 - c5) * 0.70710682868957519531 + c7;
- float tmp4 = (c3 - c5) * 0.70710682868957519531 - c7;
-
- float tmp5 = (c5 - c7) * 1.4142134189605712891 + (c5 - c7) + (c1 - c3);
- float tmp6 = (c5 - c7) * -1.4142134189605712891 + (c5 - c7) + (c1 - c3);
-
- float m1 = tmp3 * 2.6131260395050048828 + tmp5;
- float m4 = tmp3 * -2.6131260395050048828 + tmp5;
-
- float m2 = tmp4 * 1.0823919773101806641 + tmp6;
- float m3 = tmp4 * -1.0823919773101806641 + tmp6;
-
- blocks[block][0*stride + offset] = m1 * 0.49039259552955627441 + a1;
- blocks[block][7*stride + offset] = m1 * -0.49039259552955627441 + a1;
- blocks[block][1*stride + offset] = m2 * 0.41573479771614074707 + a2;
- blocks[block][6*stride + offset] = m2 * -0.41573479771614074707 + a2;
- blocks[block][2*stride + offset] = m3 * 0.27778509259223937988 + a3;
- blocks[block][5*stride + offset] = m3 * -0.27778509259223937988 + a3;
- blocks[block][3*stride + offset] = m4 * 0.097545139491558074951 + a4;
- blocks[block][4*stride + offset] = m4 * -0.097545139491558074951 + a4;
+ float t0, t1, t2, t3, t4, t5, t6, t7, u8;
+ float u0, u1, u2, u3, u4, u5, u6, u7;
+
+ /* Input */
+ t0 = blocks[block][0*stride + offset];
+ u4 = blocks[block][1*stride + offset];
+ t2 = blocks[block][2*stride + offset];
+ u6 = blocks[block][3*stride + offset];
+ t1 = blocks[block][4*stride + offset];
+ u5 = blocks[block][5*stride + offset];
+ t3 = blocks[block][6*stride + offset];
+ u7 = blocks[block][7*stride + offset];
+
+ /* Embedded scaled inverse 4-point Type-II DCT */
+ u0 = t0 + t1;
+ u1 = t0 - t1;
+ u3 = t2 + t3;
+ u2 = (t2 - t3)*(1.4142135623730950488016887242097f) - u3;
+ t0 = u0 + u3;
+ t3 = u0 - u3;
+ t1 = u1 + u2;
+ t2 = u1 - u2;
+
+ /* Embedded scaled inverse 4-point Type-IV DST */
+ t5 = u5 + u6;
+ t6 = u5 - u6;
+ t7 = u4 + u7;
+ t4 = u4 - u7;
+ u7 = t7 + t5;
+ u5 = (t7 - t5)*(1.4142135623730950488016887242097f);
+ u8 = (t4 + t6)*(1.8477590650225735122563663787936f);
+ u4 = u8 - t4*(1.0823922002923939687994464107328f);
+ u6 = u8 - t6*(2.6131259297527530557132863468544f);
+ t7 = u7;
+ t6 = t7 - u6;
+ t5 = t6 + u5;
+ t4 = t5 - u4;
+
+ /* Butterflies */
+ u0 = t0 + t7;
+ u7 = t0 - t7;
+ u6 = t1 + t6;
+ u1 = t1 - t6;
+ u2 = t2 + t5;
+ u5 = t2 - t5;
+ u4 = t3 + t4;
+ u3 = t3 - t4;
+
+ /* Output */
+ blocks[block][0*stride + offset] = u0;
+ blocks[block][1*stride + offset] = u1;
+ blocks[block][2*stride + offset] = u2;
+ blocks[block][3*stride + offset] = u3;
+ blocks[block][4*stride + offset] = u4;
+ blocks[block][5*stride + offset] = u5;
+ blocks[block][6*stride + offset] = u6;
+ blocks[block][7*stride + offset] = u7;
}
void main(void)
@@ -90,7 +120,7 @@ void main(void)
/* Coalesced load of DCT coeffs in shared memory, inverse quantization */
if (act) {
/**
- * According to spec indexing an array in push constant memory with
+ * According to the VK spec indexing an array in push constant memory
with
* a non-dynamically uniform value is illegal ($15.9.1 in v1.4.326),
* so copy the whole matrix locally.
*/
@@ -101,8 +131,9 @@ void main(void)
int qscale = qidx > 128 ? (qidx - 96) << 2 : qidx;
[[unroll]] for (uint i = 0; i < 8; ++i) {
- int v = sign_extend(int(get_px(comp, ivec2(gid.x, (gid.y << 3) +
i))), 16);
- blocks[block][i * 9 + idx] = float(v * qscale * int(qmat[(i << 3)
+ idx]));
+ int c = sign_extend(int(get_px(comp, ivec2(gid.x, (gid.y << 3) +
i))), 16);
+ float v = float(c * qscale * int(qmat[(i << 3) + idx]));
+ blocks[block][i * 9 + idx] = v * idct_8x8_scales[idx] *
idct_8x8_scales[i];
}
}
@@ -121,7 +152,7 @@ void main(void)
barrier();
if (act) {
[[unroll]] for (uint i = 0; i < 8; ++i) {
- float v = blocks[block][i * 9 + idx] * fact + off;
+ float v = round(blocks[block][i * 9 + idx] * fact + off);
put_px(comp, ivec2(gid.x, (gid.y << 3) + i), clamp(int(v), 0,
maxv));
}
}
-----------------------------------------------------------------------
Summary of changes:
libavcodec/vulkan/prores_idct.comp | 115 +++++++++++++++++++++++--------------
1 file changed, 73 insertions(+), 42 deletions(-)
hooks/post-receive
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