83 lines
2.8 KiB
C++
83 lines
2.8 KiB
C++
// Copyright (c) 2015 The WebM 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 "common/libwebm_util.h"
|
|
|
|
#include <cstdint>
|
|
#include <cstdio>
|
|
|
|
namespace libwebm {
|
|
|
|
std::int64_t NanosecondsTo90KhzTicks(std::int64_t nanoseconds) {
|
|
const double kNanosecondsPerSecond = 1000000000.0;
|
|
const double pts_seconds = nanoseconds / kNanosecondsPerSecond;
|
|
return static_cast<std::int64_t>(pts_seconds * 90000);
|
|
}
|
|
|
|
bool ParseVP9SuperFrameIndex(const std::uint8_t* frame,
|
|
std::size_t frame_length, Ranges* frame_ranges) {
|
|
if (frame == nullptr || frame_length == 0 || frame_ranges == nullptr)
|
|
return false;
|
|
|
|
bool parse_ok = false;
|
|
const std::uint8_t marker = frame[frame_length - 1];
|
|
const std::uint32_t kHasSuperFrameIndexMask = 0xe0;
|
|
const std::uint32_t kSuperFrameMarker = 0xc0;
|
|
const std::uint32_t kLengthFieldSizeMask = 0x3;
|
|
|
|
if ((marker & kHasSuperFrameIndexMask) == kSuperFrameMarker) {
|
|
const std::uint32_t kFrameCountMask = 0x7;
|
|
const int num_frames = (marker & kFrameCountMask) + 1;
|
|
const int length_field_size = ((marker >> 3) & kLengthFieldSizeMask) + 1;
|
|
const std::size_t index_length = 2 + length_field_size * num_frames;
|
|
|
|
if (frame_length < index_length) {
|
|
std::fprintf(stderr, "Webm2Pes: Invalid superframe index size.\n");
|
|
return false;
|
|
}
|
|
|
|
// Consume the super frame index. Note: it's at the end of the super frame.
|
|
const std::size_t length = frame_length - index_length;
|
|
|
|
if (length >= index_length &&
|
|
frame[frame_length - index_length] == marker) {
|
|
// Found a valid superframe index.
|
|
const std::uint8_t* byte = frame + length + 1;
|
|
|
|
std::size_t frame_offset = 0;
|
|
for (int i = 0; i < num_frames; ++i) {
|
|
std::uint32_t child_frame_length = 0;
|
|
|
|
for (int j = 0; j < length_field_size; ++j) {
|
|
child_frame_length |= (*byte++) << (j * 8);
|
|
}
|
|
|
|
frame_ranges->push_back(Range(frame_offset, child_frame_length));
|
|
frame_offset += child_frame_length;
|
|
}
|
|
|
|
if (static_cast<int>(frame_ranges->size()) != num_frames) {
|
|
std::fprintf(stderr, "Webm2Pes: superframe index parse failed.\n");
|
|
return false;
|
|
}
|
|
|
|
parse_ok = true;
|
|
} else {
|
|
std::fprintf(stderr, "Webm2Pes: Invalid superframe index.\n");
|
|
}
|
|
}
|
|
return parse_ok;
|
|
}
|
|
|
|
bool WriteUint8(std::uint8_t val, std::FILE* fileptr) {
|
|
if (fileptr == nullptr)
|
|
return false;
|
|
return (std::fputc(val, fileptr) == val);
|
|
}
|
|
|
|
} // namespace libwebm
|