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28 #define POS(x, y) src[(x) + stride * (y)]
33 int log2_size,
int c_idx)
36 ((x) >> sps->log2_min_pu_size)
38 (s->cur_frame->tab_mvf[(x) + (y) * min_pu_width])
39 #define MVF_PU(x, y) \
40 MVF(PU(x0 + ((x) * (1 << hshift))), PU(y0 + ((y) * (1 << vshift))))
41 #define IS_INTRA(x, y) \
42 (MVF_PU(x, y).pred_flag == PF_INTRA)
43 #define MIN_TB_ADDR_ZS(x, y) \
44 pps->min_tb_addr_zs[(y) * (sps->tb_mask+2) + (x)]
45 #define EXTEND(ptr, val, len) \
47 pixel4 pix = PIXEL_SPLAT_X4(val); \
48 for (i = 0; i < (len); i += 4) \
49 AV_WN4P(ptr + i, pix); \
52 #define EXTEND_RIGHT_CIP(ptr, start, length) \
53 for (i = start; i < (start) + (length); i += 4) \
54 if (!IS_INTRA(i, -1)) \
55 AV_WN4P(&ptr[i], a); \
57 a = PIXEL_SPLAT_X4(ptr[i+3])
58 #define EXTEND_LEFT_CIP(ptr, start, length) \
59 for (i = start; i > (start) - (length); i--) \
60 if (!IS_INTRA(i - 1, -1)) \
62 #define EXTEND_UP_CIP(ptr, start, length) \
63 for (i = (start); i > (start) - (length); i -= 4) \
64 if (!IS_INTRA(-1, i - 3)) \
65 AV_WN4P(&ptr[i - 3], a); \
67 a = PIXEL_SPLAT_X4(ptr[i - 3])
68 #define EXTEND_DOWN_CIP(ptr, start, length) \
69 for (i = start; i < (start) + (length); i += 4) \
70 if (!IS_INTRA(-1, i)) \
71 AV_WN4P(&ptr[i], a); \
73 a = PIXEL_SPLAT_X4(ptr[i + 3])
78 int hshift =
sps->hshift[c_idx];
79 int vshift =
sps->vshift[c_idx];
80 int size = (1 << log2_size);
81 int size_in_luma_h =
size << hshift;
82 int size_in_tbs_h = size_in_luma_h >>
sps->log2_min_tb_size;
83 int size_in_luma_v =
size << vshift;
84 int size_in_tbs_v = size_in_luma_v >>
sps->log2_min_tb_size;
87 int x_tb = (x0 >>
sps->log2_min_tb_size) &
sps->tb_mask;
88 int y_tb = (y0 >>
sps->log2_min_tb_size) &
sps->tb_mask;
89 int spin = c_idx && !size_in_tbs_v && ((2 * y0) & (1 <<
sps->log2_min_tb_size));
93 ptrdiff_t
stride =
s->cur_frame->f->linesize[c_idx] /
sizeof(
pixel);
96 int min_pu_width =
sps->min_pu_width;
99 lc->tu.intra_pred_mode;
107 pixel *top = top_array + 1;
108 pixel *filtered_left = filtered_left_array + 1;
109 pixel *filtered_top = filtered_top_array + 1;
110 int cand_bottom_left = lc->na.cand_bottom_left && cur_tb_addr >
MIN_TB_ADDR_ZS( x_tb - 1, (y_tb + size_in_tbs_v + spin) &
sps->tb_mask);
111 int cand_left = lc->na.cand_left;
112 int cand_up_left = lc->na.cand_up_left;
113 int cand_up = lc->na.cand_up;
114 int cand_up_right = lc->na.cand_up_right && !spin && cur_tb_addr >
MIN_TB_ADDR_ZS((x_tb + size_in_tbs_h) &
sps->tb_mask, y_tb - 1);
116 int bottom_left_size = (
FFMIN(y0 + 2 * size_in_luma_v,
sps->height) -
117 (y0 + size_in_luma_v)) >> vshift;
118 int top_right_size = (
FFMIN(x0 + 2 * size_in_luma_h,
sps->width) -
119 (x0 + size_in_luma_h)) >> hshift;
121 if (
pps->constrained_intra_pred_flag == 1) {
122 int size_in_luma_pu_v =
PU(size_in_luma_v);
123 int size_in_luma_pu_h =
PU(size_in_luma_h);
126 if (!size_in_luma_pu_h)
128 if (cand_bottom_left == 1 && on_pu_edge_x) {
129 int x_left_pu =
PU(x0 - 1);
130 int y_bottom_pu =
PU(y0 + size_in_luma_v);
131 int max =
FFMIN(size_in_luma_pu_v,
sps->min_pu_height - y_bottom_pu);
132 cand_bottom_left = 0;
133 for (
i = 0;
i <
max;
i += 2)
134 cand_bottom_left |= (
MVF(x_left_pu, y_bottom_pu +
i).pred_flag ==
PF_INTRA);
136 if (cand_left == 1 && on_pu_edge_x) {
137 int x_left_pu =
PU(x0 - 1);
138 int y_left_pu =
PU(y0);
139 int max =
FFMIN(size_in_luma_pu_v,
sps->min_pu_height - y_left_pu);
141 for (
i = 0;
i <
max;
i += 2)
142 cand_left |= (
MVF(x_left_pu, y_left_pu +
i).pred_flag ==
PF_INTRA);
144 if (cand_up_left == 1) {
145 int x_left_pu =
PU(x0 - 1);
146 int y_top_pu =
PU(y0 - 1);
147 cand_up_left =
MVF(x_left_pu, y_top_pu).pred_flag ==
PF_INTRA;
149 if (cand_up == 1 && on_pu_edge_y) {
150 int x_top_pu =
PU(x0);
151 int y_top_pu =
PU(y0 - 1);
152 int max =
FFMIN(size_in_luma_pu_h,
sps->min_pu_width - x_top_pu);
154 for (
i = 0;
i <
max;
i += 2)
155 cand_up |= (
MVF(x_top_pu +
i, y_top_pu).pred_flag ==
PF_INTRA);
157 if (cand_up_right == 1 && on_pu_edge_y) {
158 int y_top_pu =
PU(y0 - 1);
159 int x_right_pu =
PU(x0 + size_in_luma_h);
160 int max =
FFMIN(size_in_luma_pu_h,
sps->min_pu_width - x_right_pu);
162 for (
i = 0;
i <
max;
i += 2)
163 cand_up_right |= (
MVF(x_right_pu +
i, y_top_pu).pred_flag ==
PF_INTRA);
178 size - top_right_size);
183 if (cand_bottom_left) {
187 size - bottom_left_size);
190 if (
pps->constrained_intra_pred_flag == 1) {
191 if (cand_bottom_left || cand_left || cand_up_left || cand_up || cand_up_right) {
192 int size_max_x = x0 + ((2 *
size) << hshift) <
sps->width ?
193 2 *
size : (
sps->width - x0) >> hshift;
194 int size_max_y = y0 + ((2 *
size) << vshift) <
sps->height ?
195 2 *
size : (
sps->height - y0) >> vshift;
196 int j =
size + (cand_bottom_left? bottom_left_size: 0) -1;
197 if (!cand_up_right) {
198 size_max_x = x0 + ((
size) << hshift) <
sps->width ?
199 size : (
sps->width - x0) >> hshift;
201 if (!cand_bottom_left) {
202 size_max_y = y0 + ((
size) << vshift) <
sps->height ?
203 size : (
sps->height - y0) >> vshift;
205 if (cand_bottom_left || cand_left || cand_up_left) {
210 while (j < size_max_x && !
IS_INTRA(j, -1))
217 while (j < size_max_x && !
IS_INTRA(j, -1))
226 if (cand_bottom_left || cand_left) {
232 if (!cand_bottom_left)
234 if (x0 != 0 && y0 != 0) {
239 }
else if (x0 == 0) {
253 if (!cand_bottom_left) {
256 }
else if (cand_up_left) {
259 }
else if (cand_up) {
264 }
else if (cand_up_right) {
291 if (!
sps->intra_smoothing_disabled && (c_idx == 0 ||
sps->chroma_format_idc == 3)) {
293 int intra_hor_ver_dist_thresh[] = { 7, 1, 0 };
296 if (min_dist_vert_hor > intra_hor_ver_dist_thresh[log2_size - 3]) {
298 if (
sps->strong_intra_smoothing_enabled && c_idx == 0 &&
300 FFABS(top[-1] + top[63] - 2 * top[31]) < threshold &&
304 filtered_top[-1] = top[-1];
305 filtered_top[63] = top[63];
306 for (
i = 0;
i < 63;
i++)
307 filtered_top[
i] = ((64 - (
i + 1)) * top[-1] +
308 (
i + 1) * top[63] + 32) >> 6;
309 for (
i = 0;
i < 63;
i++)
311 (
i + 1) *
left[63] + 32) >> 6;
315 filtered_top[2 *
size - 1] = top[2 *
size - 1];
316 for (
i = 2 *
size - 2;
i >= 0;
i--)
318 left[
i - 1] + 2) >> 2;
320 filtered_left[-1] = (
left[0] + 2 *
left[-1] + top[0] + 2) >> 2;
321 for (
i = 2 *
size - 2;
i >= 0;
i--)
322 filtered_top[
i] = (top[
i + 1] + 2 * top[
i] +
323 top[
i - 1] + 2) >> 2;
324 left = filtered_left;
333 s->hpc.pred_planar[log2_size - 2]((uint8_t *)
src, (uint8_t *)top,
337 s->hpc.pred_dc((uint8_t *)
src, (uint8_t *)top,
341 s->hpc.pred_angular[log2_size - 2]((uint8_t *)
src, (uint8_t *)top,
348 #define INTRA_PRED(size) \
349 static void FUNC(intra_pred_ ## size)(HEVCLocalContext *lc, const HEVCPPS *pps, \
350 int x0, int y0, int c_idx) \
352 FUNC(intra_pred)(lc, pps, x0, y0, size, c_idx); \
363 const uint8_t *_left, ptrdiff_t
stride,
370 int size = 1 << trafo_size;
371 for (y = 0; y <
size; y++)
372 for (x = 0; x <
size; x++)
377 #define PRED_PLANAR(size)\
378 static void FUNC(pred_planar_ ## size)(uint8_t *src, const uint8_t *top, \
379 const uint8_t *left, ptrdiff_t stride) \
381 FUNC(pred_planar)(src, top, left, stride, size + 2); \
392 const uint8_t *_left,
393 ptrdiff_t
stride,
int log2_size,
int c_idx)
396 int size = (1 << log2_size);
405 dc >>= log2_size + 1;
410 for (j = 0; j <
size; j+=4)
413 if (c_idx == 0 &&
size < 32) {
414 POS(0, 0) = (
left[0] + 2 *
dc + top[0] + 2) >> 2;
415 for (x = 1; x <
size; x++)
416 POS(x, 0) = (top[x] + 3 *
dc + 2) >> 2;
417 for (y = 1; y <
size; y++)
424 const uint8_t *_left,
425 ptrdiff_t
stride,
int c_idx,
433 static const int intra_pred_angle[] = {
434 32, 26, 21, 17, 13, 9, 5, 2, 0, -2, -5, -9, -13, -17, -21, -26, -32,
435 -26, -21, -17, -13, -9, -5, -2, 0, 2, 5, 9, 13, 17, 21, 26, 32
437 static const int inv_angle[] = {
438 -4096, -1638, -910, -630, -482, -390, -315, -256, -315, -390, -482,
439 -630, -910, -1638, -4096
442 int angle = intra_pred_angle[
mode - 2];
446 int last = (
size * angle) >> 5;
450 if (angle < 0 && last < -1) {
451 for (x = 0; x <=
size; x += 4)
453 for (x = last; x <= -1; x++)
454 ref_tmp[x] =
left[-1 + ((x * inv_angle[
mode - 11] + 128) >> 8)];
458 for (y = 0; y <
size; y++) {
459 int idx = ((y + 1) * angle) >> 5;
460 int fact = ((y + 1) * angle) & 31;
462 for (x = 0; x <
size; x += 4) {
463 POS(x , y) = ((32 -
fact) *
ref[x + idx + 1] +
464 fact *
ref[x + idx + 2] + 16) >> 5;
465 POS(x + 1, y) = ((32 -
fact) *
ref[x + 1 + idx + 1] +
466 fact *
ref[x + 1 + idx + 2] + 16) >> 5;
467 POS(x + 2, y) = ((32 -
fact) *
ref[x + 2 + idx + 1] +
468 fact *
ref[x + 2 + idx + 2] + 16) >> 5;
469 POS(x + 3, y) = ((32 -
fact) *
ref[x + 3 + idx + 1] +
470 fact *
ref[x + 3 + idx + 2] + 16) >> 5;
473 for (x = 0; x <
size; x += 4)
477 if (
mode == 26 && c_idx == 0 &&
size < 32) {
478 for (y = 0; y <
size; y++)
483 if (angle < 0 && last < -1) {
484 for (x = 0; x <=
size; x += 4)
486 for (x = last; x <= -1; x++)
487 ref_tmp[x] = top[-1 + ((x * inv_angle[
mode - 11] + 128) >> 8)];
491 for (x = 0; x <
size; x++) {
492 int idx = ((x + 1) * angle) >> 5;
493 int fact = ((x + 1) * angle) & 31;
495 for (y = 0; y <
size; y++) {
497 fact *
ref[y + idx + 2] + 16) >> 5;
500 for (y = 0; y <
size; y++)
501 POS(x, y) =
ref[y + idx + 1];
504 if (
mode == 10 && c_idx == 0 &&
size < 32) {
505 for (x = 0; x <
size; x += 4) {
543 #undef EXTEND_LEFT_CIP
544 #undef EXTEND_RIGHT_CIP
546 #undef EXTEND_DOWN_CIP
552 #undef MIN_TB_ADDR_ZS
static void FUNC() pred_angular_3(uint8_t *src, const uint8_t *top, const uint8_t *left, ptrdiff_t stride, int c_idx, int mode)
#define PRED_PLANAR(size)
uint8_t ptrdiff_t const uint8_t * _src
#define EXTEND_LEFT_CIP(ptr, start, length)
#define MIN_TB_ADDR_ZS(x, y)
static av_always_inline void FUNC() intra_pred(HEVCLocalContext *lc, const HEVCPPS *pps, int x0, int y0, int log2_size, int c_idx)
#define EXTEND_DOWN_CIP(ptr, start, length)
static void FUNC() pred_angular_2(uint8_t *src, const uint8_t *top, const uint8_t *left, ptrdiff_t stride, int c_idx, int mode)
#define PIXEL_SPLAT_X4(x)
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
static av_always_inline void FUNC() pred_angular(uint8_t *_src, const uint8_t *_top, const uint8_t *_left, ptrdiff_t stride, int c_idx, int mode, int size)
#define EXTEND_UP_CIP(ptr, start, length)
#define EXTEND_RIGHT_CIP(ptr, start, length)
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled top and top right vectors is used as motion vector prediction the used motion vector is the sum of the predictor and(mvx_diff, mvy_diff) *mv_scale Intra DC Prediction block[y][x] dc[1]
static void FUNC() pred_angular_0(uint8_t *src, const uint8_t *top, const uint8_t *left, ptrdiff_t stride, int c_idx, int mode)
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
static double fact(double i)
static void FUNC() pred_dc(uint8_t *_src, const uint8_t *_top, const uint8_t *_left, ptrdiff_t stride, int log2_size, int c_idx)
#define i(width, name, range_min, range_max)
static int FUNC() sps(CodedBitstreamContext *ctx, RWContext *rw, H264RawSPS *current)
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
static void FUNC() pred_angular_1(uint8_t *src, const uint8_t *top, const uint8_t *left, ptrdiff_t stride, int c_idx, int mode)
static int ref[MAX_W *MAX_W]
#define EXTEND(ptr, val, len)
static av_always_inline void FUNC() pred_planar(uint8_t *_src, const uint8_t *_top, const uint8_t *_left, ptrdiff_t stride, int trafo_size)