Go to the documentation of this file.
28 #define POS(x, y) src[(x) + stride * (y)]
31 int log2_size,
int c_idx)
34 ((x) >> s->ps.sps->log2_min_pu_size)
36 (s->ref->tab_mvf[(x) + (y) * min_pu_width])
37 #define MVF_PU(x, y) \
38 MVF(PU(x0 + ((x) * (1 << hshift))), PU(y0 + ((y) * (1 << vshift))))
39 #define IS_INTRA(x, y) \
40 (MVF_PU(x, y).pred_flag == PF_INTRA)
41 #define MIN_TB_ADDR_ZS(x, y) \
42 s->ps.pps->min_tb_addr_zs[(y) * (s->ps.sps->tb_mask+2) + (x)]
43 #define EXTEND(ptr, val, len) \
45 pixel4 pix = PIXEL_SPLAT_X4(val); \
46 for (i = 0; i < (len); i += 4) \
47 AV_WN4P(ptr + i, pix); \
50 #define EXTEND_RIGHT_CIP(ptr, start, length) \
51 for (i = start; i < (start) + (length); i += 4) \
52 if (!IS_INTRA(i, -1)) \
53 AV_WN4P(&ptr[i], a); \
55 a = PIXEL_SPLAT_X4(ptr[i+3])
56 #define EXTEND_LEFT_CIP(ptr, start, length) \
57 for (i = start; i > (start) - (length); i--) \
58 if (!IS_INTRA(i - 1, -1)) \
60 #define EXTEND_UP_CIP(ptr, start, length) \
61 for (i = (start); i > (start) - (length); i -= 4) \
62 if (!IS_INTRA(-1, i - 3)) \
63 AV_WN4P(&ptr[i - 3], a); \
65 a = PIXEL_SPLAT_X4(ptr[i - 3])
66 #define EXTEND_DOWN_CIP(ptr, start, length) \
67 for (i = start; i < (start) + (length); i += 4) \
68 if (!IS_INTRA(-1, i)) \
69 AV_WN4P(&ptr[i], a); \
71 a = PIXEL_SPLAT_X4(ptr[i + 3])
75 int hshift =
s->ps.sps->hshift[c_idx];
76 int vshift =
s->ps.sps->vshift[c_idx];
77 int size = (1 << log2_size);
78 int size_in_luma_h =
size << hshift;
79 int size_in_tbs_h = size_in_luma_h >>
s->ps.sps->log2_min_tb_size;
80 int size_in_luma_v =
size << vshift;
81 int size_in_tbs_v = size_in_luma_v >>
s->ps.sps->log2_min_tb_size;
84 int x_tb = (x0 >>
s->ps.sps->log2_min_tb_size) &
s->ps.sps->tb_mask;
85 int y_tb = (y0 >>
s->ps.sps->log2_min_tb_size) &
s->ps.sps->tb_mask;
86 int spin = c_idx && !size_in_tbs_v && ((2 * y0) & (1 <<
s->ps.sps->log2_min_tb_size));
90 ptrdiff_t
stride =
s->frame->linesize[c_idx] /
sizeof(
pixel);
93 int min_pu_width =
s->ps.sps->min_pu_width;
96 lc->tu.intra_pred_mode;
104 pixel *top = top_array + 1;
105 pixel *filtered_left = filtered_left_array + 1;
106 pixel *filtered_top = filtered_top_array + 1;
107 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) &
s->ps.sps->tb_mask);
108 int cand_left = lc->na.cand_left;
109 int cand_up_left = lc->na.cand_up_left;
110 int cand_up = lc->na.cand_up;
111 int cand_up_right = lc->na.cand_up_right && !spin && cur_tb_addr >
MIN_TB_ADDR_ZS((x_tb + size_in_tbs_h) &
s->ps.sps->tb_mask, y_tb - 1);
113 int bottom_left_size = (
FFMIN(y0 + 2 * size_in_luma_v,
s->ps.sps->height) -
114 (y0 + size_in_luma_v)) >> vshift;
115 int top_right_size = (
FFMIN(x0 + 2 * size_in_luma_h,
s->ps.sps->width) -
116 (x0 + size_in_luma_h)) >> hshift;
118 if (
s->ps.pps->constrained_intra_pred_flag == 1) {
119 int size_in_luma_pu_v =
PU(size_in_luma_v);
120 int size_in_luma_pu_h =
PU(size_in_luma_h);
121 int on_pu_edge_x = !
av_mod_uintp2(x0,
s->ps.sps->log2_min_pu_size);
122 int on_pu_edge_y = !
av_mod_uintp2(y0,
s->ps.sps->log2_min_pu_size);
123 if (!size_in_luma_pu_h)
125 if (cand_bottom_left == 1 && on_pu_edge_x) {
126 int x_left_pu =
PU(x0 - 1);
127 int y_bottom_pu =
PU(y0 + size_in_luma_v);
128 int max =
FFMIN(size_in_luma_pu_v,
s->ps.sps->min_pu_height - y_bottom_pu);
129 cand_bottom_left = 0;
130 for (
i = 0;
i <
max;
i += 2)
131 cand_bottom_left |= (
MVF(x_left_pu, y_bottom_pu +
i).pred_flag ==
PF_INTRA);
133 if (cand_left == 1 && on_pu_edge_x) {
134 int x_left_pu =
PU(x0 - 1);
135 int y_left_pu =
PU(y0);
136 int max =
FFMIN(size_in_luma_pu_v,
s->ps.sps->min_pu_height - y_left_pu);
138 for (
i = 0;
i <
max;
i += 2)
139 cand_left |= (
MVF(x_left_pu, y_left_pu +
i).pred_flag ==
PF_INTRA);
141 if (cand_up_left == 1) {
142 int x_left_pu =
PU(x0 - 1);
143 int y_top_pu =
PU(y0 - 1);
144 cand_up_left =
MVF(x_left_pu, y_top_pu).pred_flag ==
PF_INTRA;
146 if (cand_up == 1 && on_pu_edge_y) {
147 int x_top_pu =
PU(x0);
148 int y_top_pu =
PU(y0 - 1);
149 int max =
FFMIN(size_in_luma_pu_h,
s->ps.sps->min_pu_width - x_top_pu);
151 for (
i = 0;
i <
max;
i += 2)
152 cand_up |= (
MVF(x_top_pu +
i, y_top_pu).pred_flag ==
PF_INTRA);
154 if (cand_up_right == 1 && on_pu_edge_y) {
155 int y_top_pu =
PU(y0 - 1);
156 int x_right_pu =
PU(x0 + size_in_luma_h);
157 int max =
FFMIN(size_in_luma_pu_h,
s->ps.sps->min_pu_width - x_right_pu);
159 for (
i = 0;
i <
max;
i += 2)
160 cand_up_right |= (
MVF(x_right_pu +
i, y_top_pu).pred_flag ==
PF_INTRA);
175 size - top_right_size);
180 if (cand_bottom_left) {
184 size - bottom_left_size);
187 if (
s->ps.pps->constrained_intra_pred_flag == 1) {
188 if (cand_bottom_left || cand_left || cand_up_left || cand_up || cand_up_right) {
189 int size_max_x = x0 + ((2 *
size) << hshift) <
s->ps.sps->width ?
190 2 *
size : (
s->ps.sps->width - x0) >> hshift;
191 int size_max_y = y0 + ((2 *
size) << vshift) <
s->ps.sps->height ?
192 2 *
size : (
s->ps.sps->height - y0) >> vshift;
193 int j =
size + (cand_bottom_left? bottom_left_size: 0) -1;
194 if (!cand_up_right) {
195 size_max_x = x0 + ((
size) << hshift) <
s->ps.sps->width ?
196 size : (
s->ps.sps->width - x0) >> hshift;
198 if (!cand_bottom_left) {
199 size_max_y = y0 + ((
size) << vshift) <
s->ps.sps->height ?
200 size : (
s->ps.sps->height - y0) >> vshift;
202 if (cand_bottom_left || cand_left || cand_up_left) {
207 while (j < size_max_x && !
IS_INTRA(j, -1))
214 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 (!
s->ps.sps->intra_smoothing_disabled_flag && (c_idx == 0 ||
s->ps.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 (
s->ps.sps->sps_strong_intra_smoothing_enable_flag && 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, int x0, int y0, int c_idx) \
351 FUNC(intra_pred)(lc, x0, y0, size, c_idx); \
362 const uint8_t *_left, ptrdiff_t
stride,
369 int size = 1 << trafo_size;
370 for (y = 0; y <
size; y++)
371 for (x = 0; x <
size; x++)
376 #define PRED_PLANAR(size)\
377 static void FUNC(pred_planar_ ## size)(uint8_t *src, const uint8_t *top, \
378 const uint8_t *left, ptrdiff_t stride) \
380 FUNC(pred_planar)(src, top, left, stride, size + 2); \
391 const uint8_t *_left,
392 ptrdiff_t
stride,
int log2_size,
int c_idx)
395 int size = (1 << log2_size);
404 dc >>= log2_size + 1;
409 for (j = 0; j <
size; j+=4)
412 if (c_idx == 0 &&
size < 32) {
413 POS(0, 0) = (
left[0] + 2 *
dc + top[0] + 2) >> 2;
414 for (x = 1; x <
size; x++)
415 POS(x, 0) = (top[x] + 3 *
dc + 2) >> 2;
416 for (y = 1; y <
size; y++)
423 const uint8_t *_left,
424 ptrdiff_t
stride,
int c_idx,
432 static const int intra_pred_angle[] = {
433 32, 26, 21, 17, 13, 9, 5, 2, 0, -2, -5, -9, -13, -17, -21, -26, -32,
434 -26, -21, -17, -13, -9, -5, -2, 0, 2, 5, 9, 13, 17, 21, 26, 32
436 static const int inv_angle[] = {
437 -4096, -1638, -910, -630, -482, -390, -315, -256, -315, -390, -482,
438 -630, -910, -1638, -4096
441 int angle = intra_pred_angle[
mode - 2];
445 int last = (
size * angle) >> 5;
449 if (angle < 0 && last < -1) {
450 for (x = 0; x <=
size; x += 4)
452 for (x = last; x <= -1; x++)
453 ref_tmp[x] =
left[-1 + ((x * inv_angle[
mode - 11] + 128) >> 8)];
457 for (y = 0; y <
size; y++) {
458 int idx = ((y + 1) * angle) >> 5;
459 int fact = ((y + 1) * angle) & 31;
461 for (x = 0; x <
size; x += 4) {
462 POS(x , y) = ((32 -
fact) *
ref[x + idx + 1] +
463 fact *
ref[x + idx + 2] + 16) >> 5;
464 POS(x + 1, y) = ((32 -
fact) *
ref[x + 1 + idx + 1] +
465 fact *
ref[x + 1 + idx + 2] + 16) >> 5;
466 POS(x + 2, y) = ((32 -
fact) *
ref[x + 2 + idx + 1] +
467 fact *
ref[x + 2 + idx + 2] + 16) >> 5;
468 POS(x + 3, y) = ((32 -
fact) *
ref[x + 3 + idx + 1] +
469 fact *
ref[x + 3 + idx + 2] + 16) >> 5;
472 for (x = 0; x <
size; x += 4)
476 if (
mode == 26 && c_idx == 0 &&
size < 32) {
477 for (y = 0; y <
size; y++)
482 if (angle < 0 && last < -1) {
483 for (x = 0; x <=
size; x += 4)
485 for (x = last; x <= -1; x++)
486 ref_tmp[x] = top[-1 + ((x * inv_angle[
mode - 11] + 128) >> 8)];
490 for (x = 0; x <
size; x++) {
491 int idx = ((x + 1) * angle) >> 5;
492 int fact = ((x + 1) * angle) & 31;
494 for (y = 0; y <
size; y++) {
496 fact *
ref[y + idx + 2] + 16) >> 5;
499 for (y = 0; y <
size; y++)
500 POS(x, y) =
ref[y + idx + 1];
503 if (
mode == 10 && c_idx == 0 &&
size < 32) {
504 for (x = 0; x <
size; x += 4) {
542 #undef EXTEND_LEFT_CIP
543 #undef EXTEND_RIGHT_CIP
545 #undef EXTEND_DOWN_CIP
551 #undef MIN_TB_ADDR_ZS
#define EXTEND_UP_CIP(ptr, start, length)
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_LEFT_CIP(ptr, start, length)
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)
#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 void FUNC() pred_angular_1(uint8_t *src, const uint8_t *top, const uint8_t *left, ptrdiff_t stride, int c_idx, int mode)
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)
#define i(width, name, range_min, range_max)
#define MIN_TB_ADDR_ZS(x, y)
#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 left
static av_always_inline void FUNC() intra_pred(HEVCLocalContext *lc, int x0, int y0, int log2_size, int c_idx)
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)
static int ref[MAX_W *MAX_W]
#define PRED_PLANAR(size)
#define EXTEND(ptr, val, len)
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)
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 EXTEND_DOWN_CIP(ptr, start, length)