[NORMATIVE] Set cm->prev_frame = NULL at keyframes
For non-key frames, the function get_prev_frame() takes care of
deciding what cm->prev_frame should be. But we are currently not
explicitly setting cm->prev_frame at keyframes.
This leads to the correct behaviour for the first keyframe in a
stream, since cm->prev_frame is initialized to NULL before decoding
anything, but later keyframes get wrong results since some code now
does different things depending on whether cm->prev_frame is NULL
or not.
Fix this by explicitly setting cm->prev_frame = NULL at keyframes.
BUG=aomedia:1601
Change-Id: Ibc9847945484142fc8d9a28d27aa1131f3c604f5
diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index 6eb4adc..7df756c 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -2750,6 +2750,7 @@
(av1_superres_unscaled(cm) || !NO_FILTER_FOR_IBC))
cm->allow_intrabc = aom_rb_read_bit(rb);
cm->use_ref_frame_mvs = 0;
+ cm->prev_frame = NULL;
} else {
#if CONFIG_EXPLICIT_ORDER_HINT
// Read all ref frame order hints if error_resilient_mode == 1
