44 lines
1.5 KiB
C++
44 lines
1.5 KiB
C++
/*
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* Copyright (c) 2021 Rockchip, Inc. All Rights Reserved.
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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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#include "mp3_header.h"
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static MP3_PREQ_IDX_S MP3FreqIdxTbl[13] = {
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{96000, 0}, {88200, 1}, {64000, 2}, {48000, 3}, {44100, 4},
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{32000, 5}, {24000, 6}, {22050, 7}, {16000, 8}, {12000, 9},
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{11025, 10}, {8000, 11}, {7350, 12}};
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void GetMp3Header(RKADK_U8 *pu8Mp3Hdr, RKADK_S32 u32SmpRate,
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RKADK_U8 u8Channel, RKADK_U32 u32DataLen) {
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RKADK_U8 u8FreqIdx = 0;
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for (int i = 0; i < 13; i++) {
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if (u32SmpRate == MP3FreqIdxTbl[i].u32SmpRate) {
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u8FreqIdx = MP3FreqIdxTbl[i].u8FreqIdx;
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break;
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}
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}
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RKADK_U32 u32PacketLen = u32DataLen + 7;
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pu8Mp3Hdr[0] = 0xFF;
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pu8Mp3Hdr[1] = 0xF1;
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pu8Mp3Hdr[2] =
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((MP3_PROFILE_LOW) << 6) + (u8FreqIdx << 2) + (u8Channel >> 2);
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pu8Mp3Hdr[3] = (((u8Channel & 3) << 6) + (u32PacketLen >> 11));
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pu8Mp3Hdr[4] = ((u32PacketLen & 0x7FF) >> 3);
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pu8Mp3Hdr[5] = (((u32PacketLen & 7) << 5) + 0x1F);
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pu8Mp3Hdr[6] = 0xFC;
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}
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