[NORMATIVE] Resolve enc/dec mismatch in TRAILING_BITS
Process the trailing bits at the corresponding sequence header,
frame header, and tile decoding. This makes the encoder and decoder
behavior synchronized when CONFIG_TRAILING_BITS is enabled. This
commit resolves the enc/dec mismatch issues when trailing_bits on.
STATS_CHANGED
BUG=aomedia:1641
Change-Id: I7a13f58741d1ae49f35d70d8d358b689ffbd8eba
diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index ef3bdf1..4eae946 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -62,6 +62,24 @@
#define MAX_AV1_HEADER_SIZE 80
#define ACCT_STR __func__
+#if CONFIG_TRAILING_BITS
+// Checks that the remaining bits start with a 1 and ends with 0s.
+// It consumes an additional byte, if already byte aligned before the check.
+int av1_check_trailing_bits(AV1Decoder *pbi, struct aom_read_bit_buffer *rb,
+ int *consumed_byte) {
+ AV1_COMMON *const cm = &pbi->common;
+ // bit_offset is set to 0 (mod 8) when the reader is already byte aligned
+ int bits_before_alignment = 8 - rb->bit_offset % 8;
+ *consumed_byte = (bits_before_alignment == 8);
+ int trailing = aom_rb_read_literal(rb, bits_before_alignment);
+ if (trailing != (1 << (bits_before_alignment - 1))) {
+ cm->error.error_code = AOM_CODEC_CORRUPT_FRAME;
+ return 1;
+ }
+ return 0;
+}
+#endif
+
// Use only_chroma = 1 to only set the chroma planes
static void set_planes_to_neutral_grey(AV1_COMMON *const cm,
MACROBLOCKD *const xd, int only_chroma) {
@@ -3253,6 +3271,11 @@
av1_init_read_bit_buffer(pbi, &rb, data, data_end));
#endif
+#if CONFIG_TRAILING_BITS
+ int consumed_byte = 0;
+ av1_check_trailing_bits(pbi, rb, &consumed_byte);
+#endif
+
// If cm->single_tile_decoding = 0, the independent decoding of a single tile
// or a section of a frame is not allowed.
if (!cm->single_tile_decoding &&
