audio/aidl/common/include/Utils.h

/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <aidl/android/media/audio/common/AudioChannelLayout.h>
#include <aidl/android/media/audio/common/AudioFormatDescription.h>
#include <aidl/android/media/audio/common/PcmType.h>

namespace android::hardware::audio::common {

constexpr size_t getPcmSampleSizeInBytes(::aidl::android::media::audio::common::PcmType pcm) {
    using ::aidl::android::media::audio::common::PcmType;
    switch (pcm) {
        case PcmType::UINT_8_BIT:
            return 1;
        case PcmType::INT_16_BIT:
            return 2;
        case PcmType::INT_32_BIT:
            return 4;
        case PcmType::FIXED_Q_8_24:
            return 4;
        case PcmType::FLOAT_32_BIT:
            return 4;
        case PcmType::INT_24_BIT:
            return 3;
    }
    return 0;
}

constexpr size_t getChannelCount(
        const ::aidl::android::media::audio::common::AudioChannelLayout& layout) {
    using Tag = ::aidl::android::media::audio::common::AudioChannelLayout::Tag;
    switch (layout.getTag()) {
        case Tag::none:
            return 0;
        case Tag::invalid:
            return 0;
        case Tag::indexMask:
            return __builtin_popcount(layout.get<Tag::indexMask>());
        case Tag::layoutMask:
            return __builtin_popcount(layout.get<Tag::layoutMask>());
        case Tag::voiceMask:
            return __builtin_popcount(layout.get<Tag::voiceMask>());
    }
    return 0;
}

constexpr size_t getFrameSizeInBytes(
        const ::aidl::android::media::audio::common::AudioFormatDescription& format,
        const ::aidl::android::media::audio::common::AudioChannelLayout& layout) {
    if (format == ::aidl::android::media::audio::common::AudioFormatDescription{}) {
        // Unspecified format.
        return 0;
    }
    using ::aidl::android::media::audio::common::AudioFormatType;
    if (format.type == AudioFormatType::PCM) {
        return getPcmSampleSizeInBytes(format.pcm) * getChannelCount(layout);
    } else if (format.type == AudioFormatType::NON_PCM) {
        // For non-PCM formats always use the underlying PCM size. The default value for
        // PCM is "UINT_8_BIT", thus non-encapsulated streams have the frame size of 1.
        return getPcmSampleSizeInBytes(format.pcm);
    }
    // Something unexpected.
    return 0;
}

}  // namespace android::hardware::audio::common