64 lines
2.1 KiB
C++
64 lines
2.1 KiB
C++
/*
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* Copyright (C) 2025 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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#include <cstdint>
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namespace aidl::android::hardware::audio::core {
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// Simplified APE (Monkey Audio) header definition sufficient to figure out
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// the basic parameters of the encoded file. Only supports the "current"
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// versions of the header (>= 3980).
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#pragma pack(push, 4)
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// Only the beginning of the descriptor is needed to find the header which
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// follows the descriptor.
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struct ApeDescriptor {
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uint32_t signature; // 'MAC ' or 'MACF'
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uint16_t version;
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uint16_t padding;
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uint32_t descriptorSizeBytes;
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uint32_t headerSizeBytes;
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};
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struct ApeHeader {
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uint16_t compressionLevel;
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uint16_t flags;
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uint32_t blocksPerFrame; // "frames" are encoder frames, while "blocks" are audio frames
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uint32_t lastFrameBlocks; // number of "blocks" in the last encoder "frame"
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uint32_t totalFrames; // total number of encoder "frames"
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uint16_t bitsPerSample;
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uint16_t channelCount;
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uint32_t sampleRate;
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};
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#pragma pack(pop)
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// Tries to find APE descriptor and header in the buffer. Returns the position
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// after the header or nullptr if it was not found.
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void* findApeHeader(void* buffer, size_t bufferSizeBytes, ApeHeader** header);
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// Clip duration in audio frames ("blocks" in the APE terminology).
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inline int64_t getApeClipDurationFrames(const ApeHeader* header) {
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return header->totalFrames != 0
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? (header->totalFrames - 1) * header->blocksPerFrame + header->lastFrameBlocks
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: 0;
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}
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} // namespace aidl::android::hardware::audio::core
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