hevc: optimize residual coding(cherry picked from commit 70692a44708157b4dfa50e402e446bfa2b27f55e)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 15 insertions, 65 deletions

diff --git a/libavcodec/hevc_cabac.c b/libavcodec/hevc_cabac.c
index 8468d560b9..ef3a94bc3e 100644
--- a/libavcodec/hevc_cabac.c
+++ b/libavcodec/hevc_cabac.c
@@ -764,24 +764,17 @@ int ff_hevc_last_significant_coeff_suffix_decode(HEVCContext *s,
     return value;
 }
 
-int ff_hevc_significant_coeff_group_flag_decode(HEVCContext *s, int c_idx, int x_cg,
-                                                int y_cg, int log2_trafo_size)
+int ff_hevc_significant_coeff_group_flag_decode(HEVCContext *s, int c_idx, int ctx_cg)
 {
-    int ctx_cg = 0;
     int inc;
 
-    if (x_cg < (1 << (log2_trafo_size - 2)) - 1)
-        ctx_cg += s->HEVClc.rc.significant_coeff_group_flag[x_cg + 1][y_cg];
-    if (y_cg < (1 << (log2_trafo_size - 2)) - 1)
-        ctx_cg += s->HEVClc.rc.significant_coeff_group_flag[x_cg][y_cg + 1];
-
     inc = FFMIN(ctx_cg, 1) + (c_idx>0 ? 2 : 0);
 
     return GET_CABAC(elem_offset[SIGNIFICANT_COEFF_GROUP_FLAG] + inc);
 }
 
 int ff_hevc_significant_coeff_flag_decode(HEVCContext *s, int c_idx, int x_c, int y_c,
-                                          int log2_trafo_size, int scan_idx)
+                                          int log2_trafo_size, int scan_idx, int prev_sig)
 {
     static const uint8_t ctx_idx_map[] = {
         0, 1, 4, 5, 2, 3, 4, 5, 6, 6, 8, 8, 7, 7, 8, 8
@@ -796,13 +789,6 @@ int ff_hevc_significant_coeff_flag_decode(HEVCContext *s, int c_idx, int x_c, in
     } else if (log2_trafo_size == 2) {
         sig_ctx = ctx_idx_map[(y_c << 2) + x_c];
     } else {
-        int prev_sig = 0;
-
-        if (x_cg < ((1 << log2_trafo_size) - 1) >> 2)
-            prev_sig += s->HEVClc.rc.significant_coeff_group_flag[x_cg + 1][y_cg];
-        if (y_cg < ((1 << log2_trafo_size) - 1) >> 2)
-            prev_sig += (s->HEVClc.rc.significant_coeff_group_flag[x_cg][y_cg + 1] << 1);
-
         switch (prev_sig) {
         case 0: {
                 int x_off = x_c & 3;
@@ -839,82 +825,46 @@ int ff_hevc_significant_coeff_flag_decode(HEVCContext *s, int c_idx, int x_c, in
     return GET_CABAC(elem_offset[SIGNIFICANT_COEFF_FLAG] + inc);
 }
 
-int ff_hevc_coeff_abs_level_greater1_flag_decode(HEVCContext *s, int c_idx,
-                                                 int i, int n,
-                                                 int first_elem,
-                                                 int first_subset)
+int ff_hevc_coeff_abs_level_greater1_flag_decode(HEVCContext *s, int c_idx, int inc)
 {
 
-    int inc;
-
-    if (first_elem) {
-        s->HEVClc.ctx_set = (i > 0 && c_idx == 0) ? 2 : 0;
-
-        if (!first_subset && s->HEVClc.greater1_ctx == 0)
-            s->HEVClc.ctx_set++;
-        s->HEVClc.greater1_ctx = 1;
-    }
-
-    inc = (s->HEVClc.ctx_set << 2) + s->HEVClc.greater1_ctx;
     if (c_idx > 0)
         inc += 16;
 
-    s->HEVClc.last_coeff_abs_level_greater1_flag =
-        GET_CABAC(elem_offset[COEFF_ABS_LEVEL_GREATER1_FLAG] + inc);
-
-    if (s->HEVClc.last_coeff_abs_level_greater1_flag) {
-        s->HEVClc.greater1_ctx = 0;
-    } else if (s->HEVClc.greater1_ctx > 0 && s->HEVClc.greater1_ctx < 3) {
-        s->HEVClc.greater1_ctx++;
-    }
-
-    return s->HEVClc.last_coeff_abs_level_greater1_flag;
+    return GET_CABAC(elem_offset[COEFF_ABS_LEVEL_GREATER1_FLAG] + inc);
 }
 
-int ff_hevc_coeff_abs_level_greater2_flag_decode(HEVCContext *s, int c_idx,
-                                                 int i, int n)
+int ff_hevc_coeff_abs_level_greater2_flag_decode(HEVCContext *s, int c_idx, int inc)
 {
-    int inc;
-
-    inc = s->HEVClc.ctx_set;
     if (c_idx > 0)
         inc += 4;
 
     return GET_CABAC(elem_offset[COEFF_ABS_LEVEL_GREATER2_FLAG] + inc);
 }
 
-int ff_hevc_coeff_abs_level_remaining(HEVCContext *s, int first_elem, int base_level)
+int ff_hevc_coeff_abs_level_remaining(HEVCContext *s, int base_level, int rc_rice_param)
 {
-    int i;
-    HEVCLocalContext *lc = &s->HEVClc;
     int prefix = 0;
     int suffix = 0;
-
-    if (first_elem) {
-        lc->c_rice_param = 0;
-        lc->last_coeff_abs_level_remaining = 0;
-    }
+    int last_coeff_abs_level_remaining;
+    int i;
 
     while (prefix < CABAC_MAX_BIN && get_cabac_bypass(&s->HEVClc.cc))
         prefix++;
     if (prefix == CABAC_MAX_BIN)
         av_log(s->avctx, AV_LOG_ERROR, "CABAC_MAX_BIN : %d\n", prefix);
     if (prefix < 3) {
-        for (i = 0; i < lc->c_rice_param; i++)
+        for (i = 0; i < rc_rice_param; i++)
             suffix = (suffix << 1) | get_cabac_bypass(&s->HEVClc.cc);
-        lc->last_coeff_abs_level_remaining = (prefix << lc->c_rice_param) + suffix;
+        last_coeff_abs_level_remaining = (prefix << rc_rice_param) + suffix;
     } else {
-        for (i = 0; i < prefix - 3 + lc->c_rice_param; i++)
+        int prefix_minus3 = prefix - 3;
+        for (i = 0; i < prefix_minus3 + rc_rice_param; i++)
             suffix = (suffix << 1) | get_cabac_bypass(&s->HEVClc.cc);
-        lc->last_coeff_abs_level_remaining = (((1 << (prefix - 3)) + 3 - 1)
-                                              << lc->c_rice_param) + suffix;
+        last_coeff_abs_level_remaining = (((1 << prefix_minus3) + 3 - 1)
+                                              << rc_rice_param) + suffix;
     }
-
-    lc->c_rice_param = FFMIN(lc->c_rice_param +
-                             ((base_level + lc->last_coeff_abs_level_remaining) >
-                              (3 * (1 << lc->c_rice_param))), 4);
-
-    return lc->last_coeff_abs_level_remaining;
+    return last_coeff_abs_level_remaining;
 }
 
 int ff_hevc_coeff_sign_flag(HEVCContext *s, uint8_t nb)