Updated encoder to handle intra-only frames

Updated the encoder to handle frames that are coded
intra-only. Intra-only frames must be non-showable,
that is, the "show frame" flag must be set to 0 in
the frame header.

Tested by forcing the ARF frames to be coded intra-
only.

Note: The rate control code will need to be modified
to account for intra-only frames better than they
are currently handled.

Change-Id: I6a9dd5337deddcecc599d3a44a7431909ed21079

1 files changed, 24 insertions, 29 deletions

diff --git a/vp9/encoder/vp9_onyx_if.c b/vp9/encoder/vp9_onyx_if.c
index 0afb35f54..45d323285 100644
--- a/vp9/encoder/vp9_onyx_if.c
+++ b/vp9/encoder/vp9_onyx_if.c
@@ -772,11 +772,9 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
       sf->recode_loop = (speed < 1);
 
       if (speed == 1) {
-        sf->use_square_partition_only = !(cpi->common.frame_type == KEY_FRAME ||
-                                          cpi->common.intra_only);
+        sf->use_square_partition_only = !frame_is_intra_only(&cpi->common);
         sf->less_rectangular_check  = 1;
-        sf->tx_size_search_method = (cpi->common.frame_type == KEY_FRAME ||
-                                     cpi->common.intra_only)
+        sf->tx_size_search_method = frame_is_intra_only(&cpi->common)
                                      ? USE_FULL_RD : USE_LARGESTALL;
 
         if (MIN(cpi->common.width, cpi->common.height) >= 720)
@@ -795,12 +793,10 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->intra_uv_mode_mask[TX_16X16] = INTRA_DC_H_V;
       }
       if (speed == 2) {
-        sf->use_square_partition_only = !(cpi->common.frame_type == KEY_FRAME ||
-                                          cpi->common.intra_only);
+        sf->use_square_partition_only = !frame_is_intra_only(&cpi->common);
         sf->less_rectangular_check  = 1;
-        sf->tx_size_search_method = ((cpi->common.frame_type == KEY_FRAME ||
-                                      cpi->common.intra_only)
-                                     ? USE_FULL_RD : USE_LARGESTALL);
+        sf->tx_size_search_method = frame_is_intra_only(&cpi->common)
+                                     ? USE_FULL_RD : USE_LARGESTALL;
 
         if (MIN(cpi->common.width, cpi->common.height) >= 720)
           sf->disable_split_mask = cpi->common.show_frame ?
@@ -911,8 +907,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->comp_inter_joint_search_thresh = BLOCK_SIZES;
         sf->use_one_partition_size_always = 1;
         sf->always_this_block_size = BLOCK_16X16;
-        sf->tx_size_search_method = (cpi->common.frame_type == KEY_FRAME ||
-                                     cpi->common.intra_only) ?
+        sf->tx_size_search_method = frame_is_intra_only(&cpi->common) ?
                                      USE_FULL_RD : USE_LARGESTALL;
         sf->mode_search_skip_flags = FLAG_SKIP_INTRA_DIRMISMATCH |
                                      FLAG_SKIP_INTRA_BESTINTER |
@@ -2626,7 +2621,7 @@ static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi,
   int q = cpi->active_worst_quality;
   VP9_COMMON *const cm = &cpi->common;
 
-  if (cm->frame_type == KEY_FRAME) {
+  if (frame_is_intra_only(cm)) {
 #if !CONFIG_MULTIPLE_ARF
     // Handle the special case for key frames forced when we have75 reached
     // the maximum key frame interval. Here force the Q to a range
@@ -2876,7 +2871,7 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   cpi->mv_step_param = vp9_init_search_range(cpi, max_mv_def);
   // Initialize cpi->max_mv_magnitude and cpi->mv_step_param if appropriate.
   if (sf->auto_mv_step_size) {
-    if ((cpi->common.frame_type == KEY_FRAME) || cpi->common.intra_only) {
+    if (frame_is_intra_only(&cpi->common)) {
       // Initialize max_mv_magnitude for use in the first INTER frame
       // after a key/intra-only frame.
       cpi->max_mv_magnitude = max_mv_def;
@@ -2892,8 +2887,8 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   }
 
   // Set various flags etc to special state if it is a key frame.
-  if (cm->frame_type == KEY_FRAME) {
-    // Reset the loop filter deltas and segmentation map.
+  if (frame_is_intra_only(cm)) {
+    // Reset the loop filter deltas and segmentation map
     setup_features(cm);
 
     // If segmentation is enabled force a map update for key frames.
@@ -2912,6 +2907,9 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
       cm->frame_parallel_decoding_mode = 1;
       cm->reset_frame_context = 0;
       cm->refresh_frame_context = 0;
+    } else if (cm->intra_only) {
+      // Only reset the current context.
+      cm->reset_frame_context = 2;
     }
   }
 
@@ -2961,7 +2959,7 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   loop_count = 0;
   vp9_zero(cpi->rd_tx_select_threshes);
 
-  if (cm->frame_type != KEY_FRAME) {
+  if (!frame_is_intra_only(cm)) {
     cm->mcomp_filter_type = DEFAULT_INTERP_FILTER;
     /* TODO: Decide this more intelligently */
     xd->allow_high_precision_mv = q < HIGH_PRECISION_MV_QTHRESH;
@@ -3007,20 +3005,17 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
     vp9_set_quantizer(cpi, q);
 
     if (loop_count == 0) {
-      // Set up entropy depending on frame type.
+      // Set up entropy context depending on frame type. The decoder mandates
+      // the use of the default context, index 0, for keyframes and inter
+      // frames where the error_resilient_mode or intra_only flag is set. For
+      // other inter-frames the encoder currently uses only two contexts;
+      // context 1 for ALTREF frames and context 0 for the others.
       if (cm->frame_type == KEY_FRAME) {
-        /* Choose which entropy context to use. When using a forward reference
-         * frame, it immediately follows the keyframe, and thus benefits from
-         * using the same entropy context established by the keyframe.
-         *  Otherwise, use the default context 0.
-         */
-        cm->frame_context_idx = cpi->oxcf.play_alternate;
         vp9_setup_key_frame(cpi);
       } else {
-        /* Choose which entropy context to use. Currently there are only two
-         * contexts used, one for normal frames and one for alt ref frames.
-         */
-        cpi->common.frame_context_idx = cpi->refresh_alt_ref_frame;
+        if (!cm->intra_only && !cm->error_resilient_mode) {
+          cpi->common.frame_context_idx = cpi->refresh_alt_ref_frame;
+        }
         vp9_setup_inter_frame(cpi);
       }
     }
@@ -3239,7 +3234,7 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
     vp9_adapt_coef_probs(&cpi->common);
   }
 
-  if (cpi->common.frame_type != KEY_FRAME) {
+  if (!frame_is_intra_only(&cpi->common)) {
     FRAME_COUNTS *counts = &cpi->common.counts;
 
     vp9_copy(counts->y_mode, cpi->y_mode_count);
@@ -3618,7 +3613,6 @@ int vp9_get_compressed_data(VP9_PTR ptr, unsigned int *frame_flags,
       }
 
       cm->show_frame = 0;
-      cm->intra_only = 0;
       cpi->refresh_alt_ref_frame = 1;
       cpi->refresh_golden_frame = 0;
       cpi->refresh_last_frame = 0;
@@ -3640,6 +3634,7 @@ int vp9_get_compressed_data(VP9_PTR ptr, unsigned int *frame_flags,
 #endif
     if ((cpi->source = vp9_lookahead_pop(cpi->lookahead, flush))) {
       cm->show_frame = 1;
+      cm->intra_only = 0;
 
 #if CONFIG_MULTIPLE_ARF
       // Is this frame the ARF overlay.