codec: av1: add an AV1 parser

Author: dwlsalmeida

src/codec.rs

@@ -11,6 +11,7 @@
 //! There shall be no dependencies from other modules of this crate to this module, so that it
 //! can be turned into a crate of its own if needed in the future.
 
+pub mod av1;
 pub mod h264;
 pub mod h265;
 pub mod vp8;

src/codec/av1.rs

@@ -0,0 +1,7 @@
+// Copyright 2023 The ChromiumOS Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+mod helpers;
+pub mod parser;
+pub mod reader;

src/codec/av1/helpers.rs

@@ -0,0 +1,119 @@
+// Copyright 2023 The ChromiumOS Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use crate::codec::av1::parser::NUM_REF_FRAMES;
+
+/// Implements FloorLog2(x), which is defined to be the floor of the base 2
+/// logarithm of the input x.
+///
+/// The input x will always be an integer, and will always be greater than or equal to 1.
+/// This function extracts the location of the most significant bit in x.
+pub fn floor_log2(mut x: u8) -> u8 {
+    assert!(x > 0);
+    let mut s = 0;
+
+    while x != 0 {
+        x >>= 1;
+        s += 1;
+    }
+
+    s - 1
+}
+
+pub fn get_relative_dist(enable_order_hint: bool, order_hint_bits: i32, a: i32, b: i32) -> i32 {
+    if !enable_order_hint {
+        0
+    } else {
+        let diff = a - b;
+        let m = 1 << (order_hint_bits - 1);
+        (diff & (m - 1)) - (diff & m)
+    }
+}
+
+pub fn find_latest_backward(
+    shifted_order_hints: &[i32; NUM_REF_FRAMES],
+    used_frame: &[bool; NUM_REF_FRAMES],
+    cur_frame_hint: i32,
+    latest_order_hint: &mut i32,
+) -> i32 {
+    let mut _ref = -1;
+
+    for i in 0..NUM_REF_FRAMES {
+        let hint = shifted_order_hints[i];
+        if !used_frame[i] && hint >= cur_frame_hint && (_ref < 0 || hint >= *latest_order_hint) {
+            _ref = i as i32;
+            *latest_order_hint = hint;
+        }
+    }
+
+    _ref
+}
+
+pub fn find_earliest_backward(
+    shifted_order_hints: &[i32; NUM_REF_FRAMES],
+    used_frame: &[bool; NUM_REF_FRAMES],
+    cur_frame_hint: i32,
+    earliest_order_hint: &mut i32,
+) -> i32 {
+    let mut _ref = -1;
+
+    for i in 0..NUM_REF_FRAMES {
+        let hint = shifted_order_hints[i];
+        if !used_frame[i] && hint >= cur_frame_hint && (_ref < 0 || hint < *earliest_order_hint) {
+            _ref = i as i32;
+            *earliest_order_hint = hint;
+        }
+    }
+
+    _ref
+}
+
+pub fn find_latest_forward(
+    shifted_order_hints: &[i32; NUM_REF_FRAMES],
+    used_frame: &[bool; NUM_REF_FRAMES],
+    cur_frame_hint: i32,
+    latest_order_hint: &mut i32,
+) -> i32 {
+    let mut _ref = -1;
+    for i in 0..NUM_REF_FRAMES {
+        let hint = shifted_order_hints[i];
+        if !used_frame[i] && hint < cur_frame_hint && (_ref < 0 || hint >= *latest_order_hint) {
+            _ref = i as i32;
+            *latest_order_hint = hint;
+        }
+    }
+
+    _ref
+}
+
+pub fn tile_log2(blk_size: u32, target: u32) -> u32 {
+    let mut k = 0;
+
+    while (blk_size << k) < target {
+        k += 1;
+    }
+
+    k
+}
+
+pub fn clip3(x: i32, y: i32, z: i32) -> i32 {
+    if z < x {
+        x
+    } else if z > y {
+        y
+    } else {
+        z
+    }
+}
+
+/// 5.9.29
+pub fn inverse_recenter(r: i32, v: i32) -> i32 {
+    if v > 2 * r {
+        v
+    } else if v & 1 != 0 {
+        r - ((v + 1) >> 1)
+    } else {
+        r + (v >> 1)
+    }
+}