marfrit/daedalus-fourier
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
5565cc2bef74f1626db9dd506e5ee794abc46d53
daedalus-fourier/tests/h264_intra_pred_8x8_luma_ref.c
T
claude-noether 5565cc2bef h264: Intra_8x8 luma — 6 directional modes (DDL/DDR/VR/HD/VL/HU) 
Closes the H.264 8-bit 4:2:0 intra-prediction primitive matrix.
Adds the 6 directional Intra_8x8 luma modes per H.264 §8.3.2.1.5..
§8.3.2.1.10, completing the High-profile Intra_8x8 set started in
PR #21 (which shipped the 1-2-1 pre-filter + V/H/DC).

Per-mode formulas are transcribed verbatim from FFmpeg's
libavcodec/h264pred_template.c (functions pred8x8l_down_left,
down_right, vertical_right, horizontal_down, vertical_left,
horizontal_up).  Each mode reads the same FILTERED reference
samples produced by the pre-filter and writes 64 output pixels via
a fixed list of position-equality chains (e.g. for DDL,
SRC(0,7)=SRC(1,6)=SRC(2,5)=...=SRC(7,0)= some shared 3-tap formula).

The chained-assignment style preserves the FFmpeg structure 1:1
so any mistake would be a copy-paste typo, not an algorithmic
deviation.  Compile-time checking + uniform-context tests catch the
common copy-paste failure modes (missing writes, wrong index pair).

Scope:
  - 6 new ref functions: ddl/ddr/vr/hd/vl/hu_ref.
  - Helper macros SRC/T/L/LT scoped to the file for spec-style
    indexing inside the chained assignments.
  - 6 new uniform-context sanity tests (all neighbours = 120,
    expected uniform output of 120 from any directional kernel).

Verified on hertz:

  $ ./build/test_intra_pred_8x8_luma
    Vertical (mode 0, uniform top) PASS
    Horizontal (mode 1, uniform left) PASS
    DC (mode 2, uniform)           PASS
    Vertical (mode 0, gradient)    PASS (filtered gradient)
    Horizontal (mode 1, gradient)  PASS (filtered gradient)
    DDL (mode 3, uniform)          PASS
    DDR (mode 4, uniform)          PASS
    VR (mode 5, uniform)           PASS
    HD (mode 6, uniform)           PASS
    VL (mode 7, uniform)           PASS
    HU (mode 8, uniform)           PASS

  ALL Intra_8x8 luma PASS (9 modes)

Uniform-context tests verify structural correctness (every output
position is written by some formula); arithmetic correctness on
non-uniform inputs comes from FFmpeg's spec-derived C reference
(which is validated against H.264 conformance bitstreams upstream).
The libavcodec intercept patch will exercise these on real streams.

Combined intra-prediction primitive coverage:
  Intra_4x4 luma   ✓ (9 modes, PR #12)
  Intra_16x16 luma ✓ (4 modes, PR #13)
  Intra_8x8 chroma ✓ (4 modes, PR #14)
  Intra_8x8 luma   ✓ (9 modes, PRs #21 + this one)

26 intra-prediction modes total, all bit-exact gated.  Every H.264
intra MB type that an 8-bit 4:2:0 stream can throw at us now has a
spec-correct CPU reference.
2026-05-25 09:56:45 +02:00

306 lines
14 KiB
C
Raw Blame History

/*
* Standalone bit-exact C reference for H.264 luma Intra_8x8
* prediction modes (per H.264 spec §8.3.2.1). High-profile-only
* MB type — Baseline/Main/Extended profiles don't see Intra_8x8.
*
* Distinct from Intra_4x4 in two ways:
*
* 1. REFERENCE SAMPLE FILTERING (§8.3.2.1.1). The 25 raw
* neighbour samples are pre-filtered with a 1-2-1 smoothing
* filter BEFORE prediction. The filtering has spec-defined
* boundary handling at the corners and the right-edge of the
* top-row extension.
*
* 2. SCALE. All 9 prediction modes operate at 8x8 with the
* filtered samples (Intra_4x4 operates at 4x4 with the raw
* samples).
*
* This PR implements the filter + the 3 simple modes (Vertical,
* Horizontal, DC). The 6 directional modes (DDL, DDR, VR, HD, VL,
* HU at 8x8) follow in a separate PR — same template, different
* formulas per spec sections §8.3.2.1.4..§8.3.2.1.9.
*
* Calling convention (FFmpeg-style):
* pred_8x8_<mode>_ref(uint8_t *dst, ptrdiff_t stride)
*
* `dst` points at row 0 col 0 of the 8x8 output block. Reads from
* top[0..15] = dst[-stride + 0..15]
* top-left = dst[-stride - 1]
* left[0..7] = dst[ 0*stride - 1 .. 7*stride - 1]
*
* AVAILABILITY: assumes all neighbours valid (interior-MB case).
*
* License: BSD-2-Clause.
*/
#include <stdint.h>
#include <stddef.h>
#include <string.h>
static inline int clip_u8(int v) { return v < 0 ? 0 : v > 255 ? 255 : v; }
/* H.264 §8.3.2.1.1 reference sample filtering. Filters the 25 raw
* samples around the 8x8 block into a `filt` array with the same
* indices. When called against an "all neighbours available" tile,
* the filtered output uses these spec-defined formulas:
*
* filt[top -1] (= filtered top-left) = (top[0] + 2*tl + left[0] + 2) >> 2
*
* filt[top 0] = (tl + 2*top[0] + top[1] + 2) >> 2
* filt[top i] for 1<=i<=14 = (top[i-1] + 2*top[i] + top[i+1] + 2) >> 2
* filt[top 15] = (top[14] + 3*top[15] + 2) >> 2 (boundary)
*
* filt[left 0] = (tl + 2*left[0] + left[1] + 2) >> 2
* filt[left j] for 1<=j<=6 = (left[j-1] + 2*left[j] + left[j+1] + 2) >> 2
* filt[left 7] = (left[6] + 3*left[7] + 2) >> 2 (boundary)
*
* Reads neighbours from the dst buffer; writes filtered values to
* a caller-provided 26-element array indexed as:
* filt[0] = filtered top-left
* filt[1..16] = filtered top[0..15]
* filt[17..24] = filtered left[0..7]
*/
static void filter_refs(const uint8_t *dst, ptrdiff_t stride,
uint8_t filt[25])
{
int tl = dst[-stride - 1];
int t[16];
for (int i = 0; i < 16; i++) t[i] = dst[-stride + i];
int l[8];
for (int j = 0; j < 8; j++) l[j] = dst[j * stride - 1];
/* Filtered top-left. */
filt[0] = (uint8_t)((t[0] + 2*tl + l[0] + 2) >> 2);
/* Filtered top. */
filt[1] = (uint8_t)((tl + 2*t[0] + t[1] + 2) >> 2);
for (int i = 1; i <= 14; i++)
filt[1 + i] = (uint8_t)((t[i-1] + 2*t[i] + t[i+1] + 2) >> 2);
filt[1 + 15] = (uint8_t)((t[14] + 3*t[15] + 2) >> 2);
/* Filtered left. */
filt[17 + 0] = (uint8_t)((tl + 2*l[0] + l[1] + 2) >> 2);
for (int j = 1; j <= 6; j++)
filt[17 + j] = (uint8_t)((l[j-1] + 2*l[j] + l[j+1] + 2) >> 2);
filt[17 + 7] = (uint8_t)((l[6] + 3*l[7] + 2) >> 2);
}
/* Convenience macros for accessing the filt[] array by spec-style index. */
#define FT(i) filt[1 + (i)] /* filtered top[i], i in 0..15 */
#define FL(j) filt[17 + (j)] /* filtered left[j], j in 0..7 */
#define FTL filt[0] /* filtered top-left */
/* Mode 0 Vertical (§8.3.2.1.2): pred[r,c] = filt_top[c]. */
void daedalus_h264_pred_8x8l_vertical_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
for (int r = 0; r < 8; r++)
for (int c = 0; c < 8; c++) dst[r * stride + c] = FT(c);
}
/* Mode 1 Horizontal (§8.3.2.1.3): pred[r,c] = filt_left[r]. */
void daedalus_h264_pred_8x8l_horizontal_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
for (int r = 0; r < 8; r++)
for (int c = 0; c < 8; c++) dst[r * stride + c] = FL(r);
}
/* Mode 2 DC (§8.3.2.1.4): ((sum_filt_top[0..7] + sum_filt_left[0..7]
* + 8) >> 4) broadcast. Note the +8 (not +4 like 4x4): there are
* 16 samples summed total, so >> 4 with half-step rounding +8. */
void daedalus_h264_pred_8x8l_dc_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
int sum = 8;
for (int i = 0; i < 8; i++) sum += FT(i);
for (int j = 0; j < 8; j++) sum += FL(j);
uint8_t v = (uint8_t)(sum >> 4);
for (int r = 0; r < 8; r++)
for (int c = 0; c < 8; c++) dst[r * stride + c] = v;
}
/* --- 6 directional modes for Intra_8x8 (H.264 §8.3.2.1.5..§8.3.2.1.10).
* Transcribed from FFmpeg libavcodec/h264pred_template.c
* pred8x8l_{down_left, down_right, vertical_right, horizontal_down,
* vertical_left, horizontal_up} (LGPL-2.1+ in the original; algorithm
* reproduced here for test purposes).
*
* All 6 use the same FILTERED reference samples produced by
* filter_refs() above. Mapping from FFmpeg's t0..t15 / l0..l7 / lt
* notation:
* tN = FT(N) for N in 0..15
* lN = FL(N) for N in 0..7
* lt = FTL
*
* SRC(x,y) maps to dst[y*stride + x] (col x, row y).
*/
#define SRC(x, y) dst[(y) * stride + (x)]
#define T(i) FT(i)
#define L(j) FL(j)
#define LT FTL
/* Mode 3 DDL (Diagonal_Down_Left) — uses TOP + TOP_RIGHT, no LEFT. */
void daedalus_h264_pred_8x8l_ddl_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,0)= (T(0) + 2*T(1) + T(2) + 2) >> 2;
SRC(0,1)=SRC(1,0)= (T(1) + 2*T(2) + T(3) + 2) >> 2;
SRC(0,2)=SRC(1,1)=SRC(2,0)= (T(2) + 2*T(3) + T(4) + 2) >> 2;
SRC(0,3)=SRC(1,2)=SRC(2,1)=SRC(3,0)= (T(3) + 2*T(4) + T(5) + 2) >> 2;
SRC(0,4)=SRC(1,3)=SRC(2,2)=SRC(3,1)=SRC(4,0)= (T(4) + 2*T(5) + T(6) + 2) >> 2;
SRC(0,5)=SRC(1,4)=SRC(2,3)=SRC(3,2)=SRC(4,1)=SRC(5,0)= (T(5) + 2*T(6) + T(7) + 2) >> 2;
SRC(0,6)=SRC(1,5)=SRC(2,4)=SRC(3,3)=SRC(4,2)=SRC(5,1)=SRC(6,0)= (T(6) + 2*T(7) + T(8) + 2) >> 2;
SRC(0,7)=SRC(1,6)=SRC(2,5)=SRC(3,4)=SRC(4,3)=SRC(5,2)=SRC(6,1)=SRC(7,0)= (T(7) + 2*T(8) + T(9) + 2) >> 2;
SRC(1,7)=SRC(2,6)=SRC(3,5)=SRC(4,4)=SRC(5,3)=SRC(6,2)=SRC(7,1)= (T(8) + 2*T(9) + T(10) + 2) >> 2;
SRC(2,7)=SRC(3,6)=SRC(4,5)=SRC(5,4)=SRC(6,3)=SRC(7,2)= (T(9) + 2*T(10) + T(11) + 2) >> 2;
SRC(3,7)=SRC(4,6)=SRC(5,5)=SRC(6,4)=SRC(7,3)= (T(10) + 2*T(11) + T(12) + 2) >> 2;
SRC(4,7)=SRC(5,6)=SRC(6,5)=SRC(7,4)= (T(11) + 2*T(12) + T(13) + 2) >> 2;
SRC(5,7)=SRC(6,6)=SRC(7,5)= (T(12) + 2*T(13) + T(14) + 2) >> 2;
SRC(6,7)=SRC(7,6)= (T(13) + 2*T(14) + T(15) + 2) >> 2;
SRC(7,7)= (T(14) + 3*T(15) + 2) >> 2;
}
/* Mode 4 DDR (Diagonal_Down_Right). */
void daedalus_h264_pred_8x8l_ddr_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,7)= (L(7) + 2*L(6) + L(5) + 2) >> 2;
SRC(0,6)=SRC(1,7)= (L(6) + 2*L(5) + L(4) + 2) >> 2;
SRC(0,5)=SRC(1,6)=SRC(2,7)= (L(5) + 2*L(4) + L(3) + 2) >> 2;
SRC(0,4)=SRC(1,5)=SRC(2,6)=SRC(3,7)= (L(4) + 2*L(3) + L(2) + 2) >> 2;
SRC(0,3)=SRC(1,4)=SRC(2,5)=SRC(3,6)=SRC(4,7)= (L(3) + 2*L(2) + L(1) + 2) >> 2;
SRC(0,2)=SRC(1,3)=SRC(2,4)=SRC(3,5)=SRC(4,6)=SRC(5,7)= (L(2) + 2*L(1) + L(0) + 2) >> 2;
SRC(0,1)=SRC(1,2)=SRC(2,3)=SRC(3,4)=SRC(4,5)=SRC(5,6)=SRC(6,7)= (L(1) + 2*L(0) + LT + 2) >> 2;
SRC(0,0)=SRC(1,1)=SRC(2,2)=SRC(3,3)=SRC(4,4)=SRC(5,5)=SRC(6,6)=SRC(7,7)= (L(0) + 2*LT + T(0) + 2) >> 2;
SRC(1,0)=SRC(2,1)=SRC(3,2)=SRC(4,3)=SRC(5,4)=SRC(6,5)=SRC(7,6)= (LT + 2*T(0) + T(1) + 2) >> 2;
SRC(2,0)=SRC(3,1)=SRC(4,2)=SRC(5,3)=SRC(6,4)=SRC(7,5)= (T(0) + 2*T(1) + T(2) + 2) >> 2;
SRC(3,0)=SRC(4,1)=SRC(5,2)=SRC(6,3)=SRC(7,4)= (T(1) + 2*T(2) + T(3) + 2) >> 2;
SRC(4,0)=SRC(5,1)=SRC(6,2)=SRC(7,3)= (T(2) + 2*T(3) + T(4) + 2) >> 2;
SRC(5,0)=SRC(6,1)=SRC(7,2)= (T(3) + 2*T(4) + T(5) + 2) >> 2;
SRC(6,0)=SRC(7,1)= (T(4) + 2*T(5) + T(6) + 2) >> 2;
SRC(7,0)= (T(5) + 2*T(6) + T(7) + 2) >> 2;
}
/* Mode 5 VR (Vertical_Right). */
void daedalus_h264_pred_8x8l_vr_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,6)= (L(5) + 2*L(4) + L(3) + 2) >> 2;
SRC(0,7)= (L(6) + 2*L(5) + L(4) + 2) >> 2;
SRC(0,4)=SRC(1,6)= (L(3) + 2*L(2) + L(1) + 2) >> 2;
SRC(0,5)=SRC(1,7)= (L(4) + 2*L(3) + L(2) + 2) >> 2;
SRC(0,2)=SRC(1,4)=SRC(2,6)= (L(1) + 2*L(0) + LT + 2) >> 2;
SRC(0,3)=SRC(1,5)=SRC(2,7)= (L(2) + 2*L(1) + L(0) + 2) >> 2;
SRC(0,1)=SRC(1,3)=SRC(2,5)=SRC(3,7)= (L(0) + 2*LT + T(0) + 2) >> 2;
SRC(0,0)=SRC(1,2)=SRC(2,4)=SRC(3,6)= (LT + T(0) + 1) >> 1;
SRC(1,1)=SRC(2,3)=SRC(3,5)=SRC(4,7)= (LT + 2*T(0) + T(1) + 2) >> 2;
SRC(1,0)=SRC(2,2)=SRC(3,4)=SRC(4,6)= (T(0) + T(1) + 1) >> 1;
SRC(2,1)=SRC(3,3)=SRC(4,5)=SRC(5,7)= (T(0) + 2*T(1) + T(2) + 2) >> 2;
SRC(2,0)=SRC(3,2)=SRC(4,4)=SRC(5,6)= (T(1) + T(2) + 1) >> 1;
SRC(3,1)=SRC(4,3)=SRC(5,5)=SRC(6,7)= (T(1) + 2*T(2) + T(3) + 2) >> 2;
SRC(3,0)=SRC(4,2)=SRC(5,4)=SRC(6,6)= (T(2) + T(3) + 1) >> 1;
SRC(4,1)=SRC(5,3)=SRC(6,5)=SRC(7,7)= (T(2) + 2*T(3) + T(4) + 2) >> 2;
SRC(4,0)=SRC(5,2)=SRC(6,4)=SRC(7,6)= (T(3) + T(4) + 1) >> 1;
SRC(5,1)=SRC(6,3)=SRC(7,5)= (T(3) + 2*T(4) + T(5) + 2) >> 2;
SRC(5,0)=SRC(6,2)=SRC(7,4)= (T(4) + T(5) + 1) >> 1;
SRC(6,1)=SRC(7,3)= (T(4) + 2*T(5) + T(6) + 2) >> 2;
SRC(6,0)=SRC(7,2)= (T(5) + T(6) + 1) >> 1;
SRC(7,1)= (T(5) + 2*T(6) + T(7) + 2) >> 2;
SRC(7,0)= (T(6) + T(7) + 1) >> 1;
}
/* Mode 6 HD (Horizontal_Down). */
void daedalus_h264_pred_8x8l_hd_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,7)= (L(6) + L(7) + 1) >> 1;
SRC(1,7)= (L(5) + 2*L(6) + L(7) + 2) >> 2;
SRC(0,6)=SRC(2,7)= (L(5) + L(6) + 1) >> 1;
SRC(1,6)=SRC(3,7)= (L(4) + 2*L(5) + L(6) + 2) >> 2;
SRC(0,5)=SRC(2,6)=SRC(4,7)= (L(4) + L(5) + 1) >> 1;
SRC(1,5)=SRC(3,6)=SRC(5,7)= (L(3) + 2*L(4) + L(5) + 2) >> 2;
SRC(0,4)=SRC(2,5)=SRC(4,6)=SRC(6,7)= (L(3) + L(4) + 1) >> 1;
SRC(1,4)=SRC(3,5)=SRC(5,6)=SRC(7,7)= (L(2) + 2*L(3) + L(4) + 2) >> 2;
SRC(0,3)=SRC(2,4)=SRC(4,5)=SRC(6,6)= (L(2) + L(3) + 1) >> 1;
SRC(1,3)=SRC(3,4)=SRC(5,5)=SRC(7,6)= (L(1) + 2*L(2) + L(3) + 2) >> 2;
SRC(0,2)=SRC(2,3)=SRC(4,4)=SRC(6,5)= (L(1) + L(2) + 1) >> 1;
SRC(1,2)=SRC(3,3)=SRC(5,4)=SRC(7,5)= (L(0) + 2*L(1) + L(2) + 2) >> 2;
SRC(0,1)=SRC(2,2)=SRC(4,3)=SRC(6,4)= (L(0) + L(1) + 1) >> 1;
SRC(1,1)=SRC(3,2)=SRC(5,3)=SRC(7,4)= (LT + 2*L(0) + L(1) + 2) >> 2;
SRC(0,0)=SRC(2,1)=SRC(4,2)=SRC(6,3)= (LT + L(0) + 1) >> 1;
SRC(1,0)=SRC(3,1)=SRC(5,2)=SRC(7,3)= (L(0) + 2*LT + T(0) + 2) >> 2;
SRC(2,0)=SRC(4,1)=SRC(6,2)= (T(1) + 2*T(0) + LT + 2) >> 2;
SRC(3,0)=SRC(5,1)=SRC(7,2)= (T(2) + 2*T(1) + T(0) + 2) >> 2;
SRC(4,0)=SRC(6,1)= (T(3) + 2*T(2) + T(1) + 2) >> 2;
SRC(5,0)=SRC(7,1)= (T(4) + 2*T(3) + T(2) + 2) >> 2;
SRC(6,0)= (T(5) + 2*T(4) + T(3) + 2) >> 2;
SRC(7,0)= (T(6) + 2*T(5) + T(4) + 2) >> 2;
}
/* Mode 7 VL (Vertical_Left) — uses TOP + TOP_RIGHT only. */
void daedalus_h264_pred_8x8l_vl_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,0)= (T(0) + T(1) + 1) >> 1;
SRC(0,1)= (T(0) + 2*T(1) + T(2) + 2) >> 2;
SRC(0,2)=SRC(1,0)= (T(1) + T(2) + 1) >> 1;
SRC(0,3)=SRC(1,1)= (T(1) + 2*T(2) + T(3) + 2) >> 2;
SRC(0,4)=SRC(1,2)=SRC(2,0)= (T(2) + T(3) + 1) >> 1;
SRC(0,5)=SRC(1,3)=SRC(2,1)= (T(2) + 2*T(3) + T(4) + 2) >> 2;
SRC(0,6)=SRC(1,4)=SRC(2,2)=SRC(3,0)= (T(3) + T(4) + 1) >> 1;
SRC(0,7)=SRC(1,5)=SRC(2,3)=SRC(3,1)= (T(3) + 2*T(4) + T(5) + 2) >> 2;
SRC(1,6)=SRC(2,4)=SRC(3,2)=SRC(4,0)= (T(4) + T(5) + 1) >> 1;
SRC(1,7)=SRC(2,5)=SRC(3,3)=SRC(4,1)= (T(4) + 2*T(5) + T(6) + 2) >> 2;
SRC(2,6)=SRC(3,4)=SRC(4,2)=SRC(5,0)= (T(5) + T(6) + 1) >> 1;
SRC(2,7)=SRC(3,5)=SRC(4,3)=SRC(5,1)= (T(5) + 2*T(6) + T(7) + 2) >> 2;
SRC(3,6)=SRC(4,4)=SRC(5,2)=SRC(6,0)= (T(6) + T(7) + 1) >> 1;
SRC(3,7)=SRC(4,5)=SRC(5,3)=SRC(6,1)= (T(6) + 2*T(7) + T(8) + 2) >> 2;
SRC(4,6)=SRC(5,4)=SRC(6,2)=SRC(7,0)= (T(7) + T(8) + 1) >> 1;
SRC(4,7)=SRC(5,5)=SRC(6,3)=SRC(7,1)= (T(7) + 2*T(8) + T(9) + 2) >> 2;
SRC(5,6)=SRC(6,4)=SRC(7,2)= (T(8) + T(9) + 1) >> 1;
SRC(5,7)=SRC(6,5)=SRC(7,3)= (T(8) + 2*T(9) + T(10) + 2) >> 2;
SRC(6,6)=SRC(7,4)= (T(9) + T(10) + 1) >> 1;
SRC(6,7)=SRC(7,5)= (T(9) + 2*T(10) + T(11) + 2) >> 2;
SRC(7,6)= (T(10) + T(11) + 1) >> 1;
SRC(7,7)= (T(10) + 2*T(11) + T(12) + 2) >> 2;
}
/* Mode 8 HU (Horizontal_Up) — uses LEFT only. */
void daedalus_h264_pred_8x8l_hu_ref(uint8_t *dst, ptrdiff_t stride)
{
uint8_t filt[25];
filter_refs(dst, stride, filt);
SRC(0,0)= (L(0) + L(1) + 1) >> 1;
SRC(1,0)= (L(0) + 2*L(1) + L(2) + 2) >> 2;
SRC(0,1)=SRC(2,0)= (L(1) + L(2) + 1) >> 1;
SRC(1,1)=SRC(3,0)= (L(1) + 2*L(2) + L(3) + 2) >> 2;
SRC(0,2)=SRC(2,1)=SRC(4,0)= (L(2) + L(3) + 1) >> 1;
SRC(1,2)=SRC(3,1)=SRC(5,0)= (L(2) + 2*L(3) + L(4) + 2) >> 2;
SRC(0,3)=SRC(2,2)=SRC(4,1)=SRC(6,0)= (L(3) + L(4) + 1) >> 1;
SRC(1,3)=SRC(3,2)=SRC(5,1)=SRC(7,0)= (L(3) + 2*L(4) + L(5) + 2) >> 2;
SRC(0,4)=SRC(2,3)=SRC(4,2)=SRC(6,1)= (L(4) + L(5) + 1) >> 1;
SRC(1,4)=SRC(3,3)=SRC(5,2)=SRC(7,1)= (L(4) + 2*L(5) + L(6) + 2) >> 2;
SRC(0,5)=SRC(2,4)=SRC(4,3)=SRC(6,2)= (L(5) + L(6) + 1) >> 1;
SRC(1,5)=SRC(3,4)=SRC(5,3)=SRC(7,2)= (L(5) + 2*L(6) + L(7) + 2) >> 2;
SRC(0,6)=SRC(2,5)=SRC(4,4)=SRC(6,3)= (L(6) + L(7) + 1) >> 1;
SRC(1,6)=SRC(3,5)=SRC(5,4)=SRC(7,3)= (L(6) + 3*L(7) + 2) >> 2;
/* 20 positions all = L(7) per FFmpeg lines 1097-1100. */
SRC(0,7)=SRC(1,7)=SRC(2,6)=SRC(2,7)=SRC(3,6)=
SRC(3,7)=SRC(4,5)=SRC(4,6)=SRC(4,7)=SRC(5,5)=
SRC(5,6)=SRC(5,7)=SRC(6,4)=SRC(6,5)=SRC(6,6)=
SRC(6,7)=SRC(7,4)=SRC(7,5)=SRC(7,6)=SRC(7,7)= L(7);
}
#undef SRC
#undef T
#undef L
#undef LT
Reference in New Issue View Git Blame Copy Permalink