vp9: Fix reference frame refreshes

This resolves the artifacting when decoding VP9 streams.
This commit is contained in:
ameerj 2021-08-01 22:26:00 -04:00
parent cc8ac112fc
commit a3f80a97a3
2 changed files with 30 additions and 47 deletions

View File

@ -613,7 +613,7 @@ VpxBitStreamWriter VP9::ComposeUncompressedHeader() {
// Reset context
prev_frame_probs = default_probs;
swap_next_golden = false;
swap_ref_indices = false;
loop_filter_ref_deltas.fill(0);
loop_filter_mode_deltas.fill(0);
@ -626,73 +626,57 @@ VpxBitStreamWriter VP9::ComposeUncompressedHeader() {
// intra only, meaning the frame can be recreated with no other references
current_frame_info.intra_only = true;
} else {
if (!current_frame_info.show_frame) {
uncomp_writer.WriteBit(current_frame_info.intra_only);
if (!current_frame_info.last_frame_was_key) {
swap_next_golden = !swap_next_golden;
}
} else {
current_frame_info.intra_only = false;
}
if (!current_frame_info.error_resilient_mode) {
uncomp_writer.WriteU(0, 2); // Reset frame context.
}
// Last, Golden, Altref frames
std::array<s32, 3> ref_frame_index{0, 1, 2};
// Set when next frame is hidden
// altref and golden references are swapped
if (swap_next_golden) {
ref_frame_index = std::array<s32, 3>{0, 2, 1};
const auto& curr_offsets = current_frame_info.frame_offsets;
const auto& next_offsets = next_frame.info.frame_offsets;
const bool ref_frames_different = curr_offsets[1] != curr_offsets[2];
const bool next_references_swap =
(next_offsets[1] == curr_offsets[2]) || (next_offsets[2] == curr_offsets[1]);
const bool needs_ref_swap = ref_frames_different && next_references_swap;
if (needs_ref_swap) {
swap_ref_indices = !swap_ref_indices;
}
union {
u32 raw;
BitField<0, 1, u32> refresh_last;
BitField<1, 2, u32> refresh_golden;
BitField<2, 1, u32> refresh_alt;
} refresh_frame_flags;
// update Last Frame
u64 refresh_frame_flags = 1;
// golden frame may refresh, determined if the next golden frame offset is changed
bool golden_refresh = false;
if (grace_period <= 0) {
for (s32 index = 1; index < 3; ++index) {
if (current_frame_info.frame_offsets[index] !=
next_frame.info.frame_offsets[index]) {
current_frame_info.refresh_frame[index] = true;
golden_refresh = true;
grace_period = 3;
refresh_frame_flags.raw = 0;
for (u32 index = 0; index < 3; ++index) {
// Refresh indices that use the current frame as an index
if (curr_offsets[3] == next_offsets[index]) {
refresh_frame_flags.raw |= 1u << index;
}
}
if (swap_ref_indices) {
const u32 temp = refresh_frame_flags.refresh_golden;
refresh_frame_flags.refresh_golden.Assign(refresh_frame_flags.refresh_alt.Value());
refresh_frame_flags.refresh_alt.Assign(temp);
}
if (current_frame_info.show_frame &&
(!next_frame.info.show_frame || next_frame.info.is_key_frame)) {
// Update golden frame
refresh_frame_flags = swap_next_golden ? 2 : 4;
}
if (!current_frame_info.show_frame) {
// Update altref
refresh_frame_flags = swap_next_golden ? 2 : 4;
} else if (golden_refresh) {
refresh_frame_flags = 3;
}
if (current_frame_info.intra_only) {
uncomp_writer.WriteU(frame_sync_code, 24);
uncomp_writer.WriteU(static_cast<s32>(refresh_frame_flags), 8);
uncomp_writer.WriteU(refresh_frame_flags.raw, 8);
uncomp_writer.WriteU(current_frame_info.frame_size.width - 1, 16);
uncomp_writer.WriteU(current_frame_info.frame_size.height - 1, 16);
uncomp_writer.WriteBit(false); // Render and frame size different.
} else {
uncomp_writer.WriteU(static_cast<s32>(refresh_frame_flags), 8);
for (s32 index = 1; index < 4; index++) {
const bool swap_indices = needs_ref_swap ^ swap_ref_indices;
const auto ref_frame_index = swap_indices ? std::array{0, 2, 1} : std::array{0, 1, 2};
uncomp_writer.WriteU(refresh_frame_flags.raw, 8);
for (size_t index = 1; index < 4; index++) {
uncomp_writer.WriteU(ref_frame_index[index - 1], 3);
uncomp_writer.WriteU(current_frame_info.ref_frame_sign_bias[index], 1);
}
uncomp_writer.WriteBit(true); // Frame size with refs.
uncomp_writer.WriteBit(false); // Render and frame size different.
uncomp_writer.WriteBit(current_frame_info.allow_high_precision_mv);
@ -812,7 +796,6 @@ const std::vector<u8>& VP9::ComposeFrameHeader(const NvdecCommon::NvdecRegisters
current_frame_info = curr_frame.info;
bitstream = std::move(curr_frame.bit_stream);
}
// The uncompressed header routine sets PrevProb parameters needed for the compressed header
auto uncomp_writer = ComposeUncompressedHeader();
std::vector<u8> compressed_header = ComposeCompressedHeader();

View File

@ -184,7 +184,7 @@ private:
std::array<FrameContexts, 4> frame_ctxs{};
Vp9FrameContainer next_frame{};
Vp9FrameContainer next_next_frame{};
bool swap_next_golden{};
bool swap_ref_indices{};
Vp9PictureInfo current_frame_info{};
Vp9EntropyProbs prev_frame_probs{};