60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
/*
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* common code shared by all WMA variants
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/attributes.h"
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#include "wma_common.h"
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/**
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*@brief Get the samples per frame for this stream.
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*@param sample_rate output sample_rate
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*@param version wma version
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*@param decode_flags codec compression features
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*@return log2 of the number of output samples per frame
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*/
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av_cold int ff_wma_get_frame_len_bits(int sample_rate, int version,
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unsigned int decode_flags)
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{
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int frame_len_bits;
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if (sample_rate <= 16000)
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frame_len_bits = 9;
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else if (sample_rate <= 22050 || (sample_rate <= 32000 && version == 1))
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frame_len_bits = 10;
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else if (sample_rate <= 48000 || version < 3)
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frame_len_bits = 11;
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else if (sample_rate <= 96000)
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frame_len_bits = 12;
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else
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frame_len_bits = 13;
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if (version == 3) {
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int tmp = decode_flags & 0x6;
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if (tmp == 0x2)
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++frame_len_bits;
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else if (tmp == 0x4)
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--frame_len_bits;
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else if (tmp == 0x6)
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frame_len_bits -= 2;
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}
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return frame_len_bits;
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}
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