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			85 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			85 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * AC-3 parser internal code
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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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| 
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| #ifndef AVCODEC_AC3_PARSER_INTERNAL_H
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| #define AVCODEC_AC3_PARSER_INTERNAL_H
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| 
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| #include <stddef.h>
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| #include <stdint.h>
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| 
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| #include "ac3defs.h"
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| #include "get_bits.h"
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| 
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| /**
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|  * @struct AC3HeaderInfo
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|  * Coded AC-3 header values up to the lfeon element, plus derived values.
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|  */
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| typedef struct AC3HeaderInfo {
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|     /** @name Coded elements
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|      * @{
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|      */
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|     uint16_t sync_word;
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|     uint16_t crc1;
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|     uint8_t sr_code;
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|     uint8_t bitstream_id;
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|     uint8_t bitstream_mode;
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|     uint8_t channel_mode;
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|     uint8_t lfe_on;
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|     uint8_t frame_type;
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|     int substreamid;                        ///< substream identification
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|     int center_mix_level;                   ///< Center mix level index
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|     int surround_mix_level;                 ///< Surround mix level index
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|     uint16_t channel_map;
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|     int num_blocks;                         ///< number of audio blocks
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|     int dolby_surround_mode;
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|     /** @} */
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| 
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|     /** @name Derived values
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|      * @{
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|      */
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|     uint8_t sr_shift;
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|     uint16_t sample_rate;
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|     uint32_t bit_rate;
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|     uint8_t channels;
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|     uint16_t frame_size;
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|     uint64_t channel_layout;
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|     int8_t ac3_bit_rate_code;
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|     /** @} */
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| } AC3HeaderInfo;
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| 
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| /**
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|  * Parse AC-3 frame header.
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|  * Parse the header up to the lfeon element, which is the first 52 or 54 bits
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|  * depending on the audio coding mode.
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|  * @param[in]  gbc BitContext containing the first 54 bits of the frame.
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|  * @param[out] hdr Pointer to struct where header info is written.
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|  * @return Returns 0 on success, -1 if there is a sync word mismatch,
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|  * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
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|  * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
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|  */
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| int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr);
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| 
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| int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf,
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|                             size_t size);
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| 
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| int ff_ac3_find_syncword(const uint8_t *buf, int buf_size);
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| 
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| #endif /* AVCODEC_AC3_PARSER_INTERNAL_H */
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