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/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <vector>
#include "webrtc/base/bitbuffer.h"
#include "webrtc/base/buffer.h"
#include "webrtc/base/fileutils.h"
#include "webrtc/base/logging.h"
#include "webrtc/base/pathutils.h"
#include "webrtc/base/stream.h"
#include "webrtc/common_video/h264/h264_common.h"
#include "webrtc/common_video/h264/sps_vui_rewriter.h"
#include "webrtc/test/gtest.h"
namespace webrtc {
enum SpsMode {
kNoRewriteRequired_PocCorrect,
kNoRewriteRequired_VuiOptimal,
kRewriteRequired_NoVui,
kRewriteRequired_NoBitstreamRestriction,
kRewriteRequired_VuiSuboptimal,
};
static const size_t kSpsBufferMaxSize = 256;
static const size_t kWidth = 640;
static const size_t kHeight = 480;
// Generates a fake SPS with basically everything empty and with characteristics
// based off SpsMode.
// Pass in a buffer of at least kSpsBufferMaxSize.
// The fake SPS that this generates also always has at least one emulation byte
// at offset 2, since the first two bytes are always 0, and has a 0x3 as the
// level_idc, to make sure the parser doesn't eat all 0x3 bytes.
void GenerateFakeSps(SpsMode mode, rtc::Buffer* out_buffer) {
uint8_t rbsp[kSpsBufferMaxSize] = {0};
rtc::BitBufferWriter writer(rbsp, kSpsBufferMaxSize);
// Profile byte.
writer.WriteUInt8(0);
// Constraint sets and reserved zero bits.
writer.WriteUInt8(0);
// level_idc.
writer.WriteUInt8(3);
// seq_paramter_set_id.
writer.WriteExponentialGolomb(0);
// Profile is not special, so we skip all the chroma format settings.
// Now some bit magic.
// log2_max_frame_num_minus4: ue(v). 0 is fine.
writer.WriteExponentialGolomb(0);
// pic_order_cnt_type: ue(v).
// POC type 2 is the one that doesn't need to be rewritten.
if (mode == kNoRewriteRequired_PocCorrect) {
writer.WriteExponentialGolomb(2);
} else {
writer.WriteExponentialGolomb(0);
// log2_max_pic_order_cnt_lsb_minus4: ue(v). 0 is fine.
writer.WriteExponentialGolomb(0);
}
// max_num_ref_frames: ue(v). Use 1, to make optimal/suboptimal more obvious.
writer.WriteExponentialGolomb(1);
// gaps_in_frame_num_value_allowed_flag: u(1).
writer.WriteBits(0, 1);
// Next are width/height. First, calculate the mbs/map_units versions.
uint16_t width_in_mbs_minus1 = (kWidth + 15) / 16 - 1;
// For the height, we're going to define frame_mbs_only_flag, so we need to
// divide by 2. See the parser for the full calculation.
uint16_t height_in_map_units_minus1 = ((kHeight + 15) / 16 - 1) / 2;
// Write each as ue(v).
writer.WriteExponentialGolomb(width_in_mbs_minus1);
writer.WriteExponentialGolomb(height_in_map_units_minus1);
// frame_mbs_only_flag: u(1). Needs to be false.
writer.WriteBits(0, 1);
// mb_adaptive_frame_field_flag: u(1).
writer.WriteBits(0, 1);
// direct_8x8_inferene_flag: u(1).
writer.WriteBits(0, 1);
// frame_cropping_flag: u(1). 1, so we can supply crop.
writer.WriteBits(1, 1);
// Now we write the left/right/top/bottom crop. For simplicity, we'll put all
// the crop at the left/top.
// We picked a 4:2:0 format, so the crops are 1/2 the pixel crop values.
// Left/right.
writer.WriteExponentialGolomb(((16 - (kWidth % 16)) % 16) / 2);
writer.WriteExponentialGolomb(0);
// Top/bottom.
writer.WriteExponentialGolomb(((16 - (kHeight % 16)) % 16) / 2);
writer.WriteExponentialGolomb(0);
// Finally! The VUI.
// vui_parameters_present_flag: u(1)
if (mode == kNoRewriteRequired_PocCorrect || mode == kRewriteRequired_NoVui) {
writer.WriteBits(0, 1);
} else {
writer.WriteBits(1, 1);
// VUI time. 8 flags to ignore followed by the bitstream restriction flag.
writer.WriteBits(0, 8);
if (mode == kRewriteRequired_NoBitstreamRestriction) {
writer.WriteBits(0, 1);
} else {
writer.WriteBits(1, 1);
// Write some defaults. Shouldn't matter for parsing, though.
// motion_vectors_over_pic_boundaries_flag: u(1)
writer.WriteBits(1, 1);
// max_bytes_per_pic_denom: ue(v)
writer.WriteExponentialGolomb(2);
// max_bits_per_mb_denom: ue(v)
writer.WriteExponentialGolomb(1);
// log2_max_mv_length_horizontal: ue(v)
// log2_max_mv_length_vertical: ue(v)
writer.WriteExponentialGolomb(16);
writer.WriteExponentialGolomb(16);
// Next are the limits we care about.
// max_num_reorder_frames: ue(v)
// max_dec_frame_buffering: ue(v)
if (mode == kRewriteRequired_VuiSuboptimal) {
writer.WriteExponentialGolomb(4);
writer.WriteExponentialGolomb(4);
} else if (kNoRewriteRequired_VuiOptimal) {
writer.WriteExponentialGolomb(0);
writer.WriteExponentialGolomb(1);
}
}
}
// Get the number of bytes written (including the last partial byte).
size_t byte_count, bit_offset;
writer.GetCurrentOffset(&byte_count, &bit_offset);
if (bit_offset > 0) {
byte_count++;
}
// Write the NALU header and type; {0 0 0 1} and 7 for the SPS header type.
uint8_t header[] = {0, 0, 0, 1, 7};
out_buffer->AppendData(header, sizeof(header));
H264::WriteRbsp(rbsp, byte_count, out_buffer);
}
void TestSps(SpsMode mode, SpsVuiRewriter::ParseResult expected_parse_result) {
rtc::LogMessage::LogToDebug(rtc::LS_VERBOSE);
rtc::Buffer buffer;
GenerateFakeSps(mode, &buffer);
std::vector<H264::NaluIndex> start_offsets =
H264::FindNaluIndices(buffer.data(), buffer.size());
EXPECT_EQ(1u, start_offsets.size());
H264::NaluIndex index = start_offsets[0];
H264::NaluType nal_type =
H264::ParseNaluType(buffer[index.payload_start_offset]);
EXPECT_EQ(H264::kSps, nal_type);
index.payload_start_offset += H264::kNaluTypeSize;
index.payload_size -= H264::kNaluTypeSize;
rtc::Optional<SpsParser::SpsState> sps;
rtc::Buffer out_buffer;
SpsVuiRewriter::ParseResult result =
SpsVuiRewriter::ParseAndRewriteSps(&buffer[index.payload_start_offset],
index.payload_size, &sps, &out_buffer);
EXPECT_EQ(expected_parse_result, result);
}
#define REWRITE_TEST(test_name, mode, expected_parse_result) \
TEST(SpsVuiRewriterTest, test_name) { TestSps(mode, expected_parse_result); }
REWRITE_TEST(PocCorrect,
kNoRewriteRequired_PocCorrect,
SpsVuiRewriter::ParseResult::kPocOk);
REWRITE_TEST(VuiAlreadyOptimal,
kNoRewriteRequired_VuiOptimal,
SpsVuiRewriter::ParseResult::kVuiOk);
REWRITE_TEST(RewriteFullVui,
kRewriteRequired_NoVui,
SpsVuiRewriter::ParseResult::kVuiRewritten);
REWRITE_TEST(AddBitstreamRestriction,
kRewriteRequired_NoBitstreamRestriction,
SpsVuiRewriter::ParseResult::kVuiRewritten);
REWRITE_TEST(RewriteSuboptimalVui,
kRewriteRequired_VuiSuboptimal,
SpsVuiRewriter::ParseResult::kVuiRewritten);
} // namespace webrtc
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