Unconditionally use LAST_FRAME for prev_frame.

BUG=aomedia:78

Change-Id: Id85cf22302317d33b593345fd31090a6620f4101

av1/common/onyxc_int.h

@@ -662,9 +662,8 @@ static INLINE int frame_might_use_prev_frame_mvs(const AV1_COMMON *cm) {
 
 // Returns 1 if this frame really can use MVs from some previous frame.
 static INLINE int frame_can_use_prev_frame_mvs(const AV1_COMMON *cm) {
-  return (frame_might_use_prev_frame_mvs(cm) && cm->last_show_frame &&
-          cm->prev_frame && !cm->prev_frame->intra_only &&
-          cm->width == cm->prev_frame->width &&
+  return (frame_might_use_prev_frame_mvs(cm) && cm->prev_frame &&
+          !cm->prev_frame->intra_only && cm->width == cm->prev_frame->width &&
           cm->height == cm->prev_frame->height);
 }
 #endif

av1/decoder/decodeframe.c

@@ -2973,6 +2973,11 @@ static size_t read_uncompressed_header(AV1Decoder *pbi,
       else
         cm->use_ref_frame_mvs = 0;
 
+      cm->prev_frame =
+          cm->frame_refs[LAST_FRAME - LAST_FRAME].idx != INVALID_IDX
+              ? &cm->buffer_pool
+                     ->frame_bufs[cm->frame_refs[LAST_FRAME - LAST_FRAME].idx]
+              : NULL;
       cm->use_prev_frame_mvs =
           cm->use_ref_frame_mvs && frame_can_use_prev_frame_mvs(cm);
 #endif
@@ -3233,6 +3238,7 @@ static size_t read_uncompressed_header(AV1Decoder *pbi,
   if (cm->use_adapt_scan == 0) av1_init_scan_order(cm);
 #endif  // CONFIG_ADAPT_SCAN
 
+#if !CONFIG_TEMPMV_SIGNALING
   // NOTE(zoeliu): As cm->prev_frame can take neither a frame of
   //               show_exisiting_frame=1, nor can it take a frame not used as
   //               a reference, it is probable that by the time it is being
@@ -3251,6 +3257,7 @@ static size_t read_uncompressed_header(AV1Decoder *pbi,
                    ->frame_bufs[cm->frame_refs[LAST_FRAME - LAST_FRAME].idx]
             : NULL;
   }
+#endif
 
 #if CONFIG_TEMPMV_SIGNALING
   if (cm->use_prev_frame_mvs && !frame_can_use_prev_frame_mvs(cm)) {
@@ -3429,7 +3436,9 @@ size_t av1_decode_frame_headers_and_setup(AV1Decoder *pbi, const uint8_t *data,
   uint8_t clear_data[MAX_AV1_HEADER_SIZE];
   size_t first_partition_size;
   YV12_BUFFER_CONFIG *new_fb;
+#if !CONFIG_TEMPMV_SIGNALING
   RefBuffer *last_fb_ref_buf = &cm->frame_refs[LAST_FRAME - LAST_FRAME];
+#endif
 
 #if CONFIG_ADAPT_SCAN
   av1_deliver_eob_threshold(cm, xd);
@@ -3489,6 +3498,7 @@ size_t av1_decode_frame_headers_and_setup(AV1Decoder *pbi, const uint8_t *data,
 
   cm->setup_mi(cm);
 
+#if !CONFIG_TEMPMV_SIGNALING
   // NOTE(zoeliu): As cm->prev_frame can take neither a frame of
   //               show_exisiting_frame=1, nor can it take a frame not used as
   //               a reference, it is probable that by the time it is being
@@ -3505,6 +3515,7 @@ size_t av1_decode_frame_headers_and_setup(AV1Decoder *pbi, const uint8_t *data,
                          ? &cm->buffer_pool->frame_bufs[last_fb_ref_buf->idx]
                          : NULL;
   }
+#endif
 
 #if CONFIG_TEMPMV_SIGNALING
   if (cm->use_prev_frame_mvs && !frame_can_use_prev_frame_mvs(cm)) {

av1/encoder/encodeframe.c

@@ -4170,6 +4170,11 @@ static void encode_frame_internal(AV1_COMP *cpi) {
   av1_initialize_me_consts(cpi, x, cm->base_qindex);
   init_encode_frame_mb_context(cpi);
 
+#if CONFIG_TEMPMV_SIGNALING
+  cm->prev_frame = last_fb_buf_idx != INVALID_IDX
+                       ? &cm->buffer_pool->frame_bufs[last_fb_buf_idx]
+                       : NULL;
+#else
   // NOTE(zoeliu): As cm->prev_frame can take neither a frame of
   //               show_exisiting_frame=1, nor can it take a frame not used as
   //               a reference, it is probable that by the time it is being
@@ -4186,6 +4191,7 @@ static void encode_frame_internal(AV1_COMP *cpi) {
                          ? &cm->buffer_pool->frame_bufs[last_fb_buf_idx]
                          : NULL;
   }
+#endif
 
 #if CONFIG_TEMPMV_SIGNALING
   cm->use_prev_frame_mvs &= frame_can_use_prev_frame_mvs(cm);