Implement intra-coded frames

Implements ability to signal and decode frames that are
encoded using only intra coding modes. Only the decode
side has been implemented here.

Change-Id: I53ac6a8d90422cd08ba389e5236e15b45f9e93de

vp9/common/vp9_entropy.c

@@ -723,7 +723,7 @@ void vp9_adapt_coef_probs(VP9_COMMON *cm) {
   int count_sat;
   int update_factor; /* denominator 256 */
 
-  if (cm->frame_type == KEY_FRAME) {
+  if ((cm->frame_type == KEY_FRAME) || cm->intra_only) {
     update_factor = COEF_MAX_UPDATE_FACTOR_KEY;
     count_sat = COEF_COUNT_SAT_KEY;
   } else if (cm->last_frame_type == KEY_FRAME) {

vp9/common/vp9_entropymode.c

@@ -536,8 +536,16 @@ void vp9_setup_past_independence(VP9_COMMON *cm, MACROBLOCKD *xd) {
 
   vp9_init_mode_contexts(cm);
 
-  for (i = 0; i < NUM_FRAME_CONTEXTS; i++)
-    vpx_memcpy(&cm->frame_contexts[i], &cm->fc, sizeof(cm->fc));
+  if ((cm->frame_type == KEY_FRAME) ||
+      cm->error_resilient_mode || (cm->reset_frame_context == 3)) {
+    // Reset all frame contexts.
+    for (i = 0; i < NUM_FRAME_CONTEXTS; ++i)
+      vpx_memcpy(&cm->frame_contexts[i], &cm->fc, sizeof(cm->fc));
+  } else if (cm->reset_frame_context == 2) {
+    // Reset only the frame context specified in the frame header.
+    vpx_memcpy(&cm->frame_contexts[cm->frame_context_idx], &cm->fc,
+               sizeof(cm->fc));
+  }
 
   vpx_memset(cm->prev_mip, 0,
              cm->mode_info_stride * (cm->mi_rows + 1) * sizeof(MODE_INFO));

vp9/common/vp9_onyxc_int.h

@@ -364,6 +364,7 @@ static void set_prev_mi(VP9_COMMON *cm) {
   const int use_prev_in_find_mv_refs = cm->width == cm->last_width &&
                                        cm->height == cm->last_height &&
                                        !cm->error_resilient_mode &&
+                                       !cm->intra_only &&
                                        cm->last_show_frame;
   // Special case: set prev_mi to NULL when the previous mode info
   // context cannot be used.

vp9/decoder/vp9_decodemv.c

@@ -337,7 +337,7 @@ static INLINE COMPPREDMODE_TYPE read_comp_pred_mode(vp9_reader *r) {
 static void mb_mode_mv_init(VP9D_COMP *pbi, vp9_reader *r) {
   VP9_COMMON *const cm = &pbi->common;
 
-  if (cm->frame_type != KEY_FRAME) {
+  if ((cm->frame_type != KEY_FRAME) && (!cm->intra_only)) {
     nmv_context *const nmvc = &pbi->common.fc.nmvc;
     MACROBLOCKD *const xd = &pbi->mb;
     int i, j;
@@ -816,7 +816,7 @@ void vp9_decode_mb_mode_mv(VP9D_COMP* const pbi,
   MODE_INFO *mi = xd->mode_info_context;
   MB_MODE_INFO *const mbmi = &mi->mbmi;
 
-  if (cm->frame_type == KEY_FRAME) {
+  if ((cm->frame_type == KEY_FRAME) || cm->intra_only) {
     kfread_modes(pbi, mi, mi_row, mi_col, r);
   } else {
     read_mb_modes_mv(pbi, mi, &mi->mbmi, mi_row, mi_col, r);

vp9/decoder/vp9_decodframe.c

@@ -308,7 +308,7 @@ static void decode_atom(VP9D_COMP *pbi, MACROBLOCKD *xd,
 
   assert(mbmi->ref_frame[0] != INTRA_FRAME);
 
-  if (pbi->common.frame_type != KEY_FRAME)
+  if ((pbi->common.frame_type != KEY_FRAME) && (!pbi->common.intra_only))
     vp9_setup_interp_filters(xd, mbmi->interp_filter, &pbi->common);
 
   // prediction
@@ -1062,8 +1062,6 @@ static size_t read_uncompressed_header(VP9D_COMP *pbi,
       }
     }
 
-    vp9_setup_past_independence(cm, xd);
-
     pbi->refresh_frame_flags = (1 << NUM_REF_FRAMES) - 1;
 
     for (i = 0; i < ALLOWED_REFS_PER_FRAME; ++i)
@@ -1073,11 +1071,12 @@ static size_t read_uncompressed_header(VP9D_COMP *pbi,
   } else {
     cm->intra_only = cm->show_frame ? 0 : vp9_rb_read_bit(rb);
 
-    if (cm->error_resilient_mode)
-      vp9_setup_past_independence(cm, xd);
+    cm->reset_frame_context = cm->error_resilient_mode ?
+        0 : vp9_rb_read_literal(rb, 2);
 
     if (cm->intra_only) {
       check_sync_code(cm, rb);
+
       pbi->refresh_frame_flags = vp9_rb_read_literal(rb, NUM_REF_FRAMES);
       setup_frame_size(pbi, rb);
     } else {
@@ -1102,17 +1101,19 @@ static size_t read_uncompressed_header(VP9D_COMP *pbi,
   }
 
   if (!cm->error_resilient_mode) {
-    cm->reset_frame_context = vp9_rb_read_literal(rb, 2);
     cm->refresh_frame_context = vp9_rb_read_bit(rb);
     cm->frame_parallel_decoding_mode = vp9_rb_read_bit(rb);
   } else {
-    cm->reset_frame_context = 0;
     cm->refresh_frame_context = 0;
     cm->frame_parallel_decoding_mode = 1;
   }
 
   cm->frame_context_idx = vp9_rb_read_literal(rb, NUM_FRAME_CONTEXTS_LG2);
 
+  if ((cm->frame_type == KEY_FRAME) ||
+      cm->error_resilient_mode || cm->intra_only)
+    vp9_setup_past_independence(cm, xd);
+
   setup_loopfilter(pbi, rb);
   setup_quantization(pbi, rb);
   setup_segmentation(pbi, rb);
@@ -1215,7 +1216,7 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
   if (!pc->error_resilient_mode && !pc->frame_parallel_decoding_mode) {
     vp9_adapt_coef_probs(pc);
 
-    if (!keyframe) {
+    if ((!keyframe) && (!pc->intra_only)) {
       vp9_adapt_mode_probs(pc);
       vp9_adapt_mode_context(pc);
       vp9_adapt_nmv_probs(pc, xd->allow_high_precision_mv);

vp9/encoder/vp9_bitstream.c

@@ -821,7 +821,7 @@ static void write_modes_b(VP9_COMP *cpi, MODE_INFO *m, vp9_writer *bc,
   set_mi_row_col(&cpi->common, xd, mi_row,
                  1 << mi_height_log2(m->mbmi.sb_type),
                  mi_col, 1 << mi_width_log2(m->mbmi.sb_type));
-  if (cm->frame_type == KEY_FRAME) {
+  if ((cm->frame_type == KEY_FRAME) || cm->intra_only) {
     write_mb_modes_kf(cpi, m, bc, mi_row, mi_col);
 #ifdef ENTROPY_STATS
     active_section = 8;
@@ -1527,8 +1527,12 @@ static void write_uncompressed_header(VP9_COMP *cpi,
     if (!cm->show_frame)
       vp9_wb_write_bit(wb, cm->intra_only);
 
+    if (!cm->error_resilient_mode)
+      vp9_wb_write_literal(wb, cm->reset_frame_context, 2);
+
     if (cm->intra_only) {
       write_sync_code(wb);
+
       vp9_wb_write_literal(wb, get_refresh_mask(cpi), NUM_REF_FRAMES);
       write_frame_size(cpi, wb);
     } else {
@@ -1549,7 +1553,6 @@ static void write_uncompressed_header(VP9_COMP *cpi,
   }
 
   if (!cm->error_resilient_mode) {
-    vp9_wb_write_literal(wb, cm->reset_frame_context, 2);
     vp9_wb_write_bit(wb, cm->refresh_frame_context);
     vp9_wb_write_bit(wb, cm->frame_parallel_decoding_mode);
   }

vp9/encoder/vp9_ratectrl.c

@@ -206,7 +206,7 @@ void vp9_setup_key_frame(VP9_COMP *cpi) {
 void vp9_setup_inter_frame(VP9_COMP *cpi) {
   VP9_COMMON *cm = &cpi->common;
   MACROBLOCKD *xd = &cpi->mb.e_mbd;
-  if (cm->error_resilient_mode)
+  if (cm->error_resilient_mode || cm->intra_only)
     vp9_setup_past_independence(cm, xd);
 
   assert(cm->frame_context_idx < NUM_FRAME_CONTEXTS);