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https://github.com/mollyim/webrtc.git
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edb7ea2e69
Biggest change is a new helper class used to read data from the
bitstream and then pass the result to a function if reading was
successful. There's also helper to do if/else flow based on the read
values. This avoids a bunch of temporaries and in my view makes the
code esaier to read.
For example, this block:
uint32_t bit;
RETURN_FALSE_IF_ERROR(br->ReadBits(&bit, 1));
if (bit) {
RETURN_FALSE_IF_ERROR(br->ConsumeBits(7));
}
...is now written as:
RETURN_IF_FALSE(
br->IfNextBoolean([br] { return br->ConsumeBits(7); }));
In addition, we parse and put a few extra things in FrameInfo:
show_existing_frame, is_keyframe, and base_qp.
Bug: webrtc:12354
Change-Id: Ia0b707b223a1afe0a4521ce2b995437d41243c06
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/215239
Commit-Queue: Erik Språng <sprang@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33776}
92 lines
2.8 KiB
C++
92 lines
2.8 KiB
C++
/*
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* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
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#define MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
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#include <stddef.h>
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#include <stdint.h>
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#include "absl/types/optional.h"
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namespace webrtc {
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namespace vp9 {
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// Gets the QP, QP range: [0, 255].
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// Returns true on success, false otherwise.
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bool GetQp(const uint8_t* buf, size_t length, int* qp);
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// Bit depth per channel. Support varies by profile.
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enum class BitDept : uint8_t {
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k8Bit = 8,
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k10Bit = 10,
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k12Bit = 12,
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};
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enum class ColorSpace : uint8_t {
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CS_UNKNOWN = 0, // Unknown (in this case the color space must be signaled
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// outside the VP9 bitstream).
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CS_BT_601 = 1, // CS_BT_601 Rec. ITU-R BT.601-7
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CS_BT_709 = 2, // Rec. ITU-R BT.709-6
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CS_SMPTE_170 = 3, // SMPTE-170
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CS_SMPTE_240 = 4, // SMPTE-240
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CS_BT_2020 = 5, // Rec. ITU-R BT.2020-2
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CS_RESERVED = 6, // Reserved
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CS_RGB = 7, // sRGB (IEC 61966-2-1)
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};
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enum class ColorRange {
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kStudio, // Studio swing:
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// For BitDepth equals 8:
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// Y is between 16 and 235 inclusive.
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// U and V are between 16 and 240 inclusive.
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// For BitDepth equals 10:
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// Y is between 64 and 940 inclusive.
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// U and V are between 64 and 960 inclusive.
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// For BitDepth equals 12:
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// Y is between 256 and 3760.
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// U and V are between 256 and 3840 inclusive.
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kFull // Full swing; no restriction on Y, U, V values.
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};
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enum class YuvSubsampling {
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k444,
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k440,
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k422,
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k420,
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};
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struct FrameInfo {
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int profile = 0; // Profile 0-3 are valid.
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absl::optional<uint8_t> show_existing_frame;
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bool is_keyframe = false;
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bool show_frame = false;
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bool error_resilient = false;
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BitDept bit_detph = BitDept::k8Bit;
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ColorSpace color_space = ColorSpace::CS_UNKNOWN;
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ColorRange color_range;
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YuvSubsampling sub_sampling;
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int frame_width = 0;
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int frame_height = 0;
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int render_width = 0;
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int render_height = 0;
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int base_qp = 0;
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};
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// Parses frame information for a VP9 key-frame or all-intra frame from a
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// bitstream. Returns nullopt on failure or if not a key-frame.
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absl::optional<FrameInfo> ParseIntraFrameInfo(const uint8_t* buf,
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size_t length);
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} // namespace vp9
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} // namespace webrtc
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#endif // MODULES_VIDEO_CODING_UTILITY_VP9_UNCOMPRESSED_HEADER_PARSER_H_
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