63 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			63 lines
		
	
	
		
			1.9 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 Libav.
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|  *
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|  * Libav 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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|  * Libav 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 Libav; 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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| 
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| #include "libavutil/attributes.h"
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| #include "wma_common.h"
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| 
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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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| 
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|     int frame_len_bits;
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| 
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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 ||
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|              (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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|     }
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| 
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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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|     }
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| 
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|     return frame_len_bits;
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| }
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