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			120 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			120 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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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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| #include <stddef.h>
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| #include <stdint.h>
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| 
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| #include "atsc_a53.h"
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| #include "get_bits.h"
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| 
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| int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len,
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|                      void **data, size_t *sei_size)
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| {
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|     AVFrameSideData *side_data = NULL;
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|     uint8_t *sei_data;
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| 
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|     if (frame)
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|         side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC);
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| 
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|     if (!side_data) {
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|         *data = NULL;
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|         return 0;
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|     }
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| 
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|     *sei_size = side_data->size + 11;
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|     *data = av_mallocz(*sei_size + prefix_len);
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|     if (!*data)
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|         return AVERROR(ENOMEM);
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|     sei_data = (uint8_t*)*data + prefix_len;
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| 
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|     // country code
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|     sei_data[0] = 181;
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|     sei_data[1] = 0;
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|     sei_data[2] = 49;
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| 
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|     /**
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|      * 'GA94' is standard in North America for ATSC, but hard coding
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|      * this style may not be the right thing to do -- other formats
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|      * do exist. This information is not available in the side_data
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|      * so we are going with this right now.
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|      */
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|     AV_WL32(sei_data + 3, MKTAG('G', 'A', '9', '4'));
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|     sei_data[7] = 3;
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|     sei_data[8] = ((side_data->size/3) & 0x1f) | 0x40;
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|     sei_data[9] = 0;
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| 
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|     memcpy(sei_data + 10, side_data->data, side_data->size);
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| 
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|     sei_data[side_data->size+10] = 255;
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| 
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|     return 0;
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| }
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| 
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| int ff_parse_a53_cc(AVBufferRef **pbuf, const uint8_t *data, int size)
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| {
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|     AVBufferRef *buf = *pbuf;
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|     GetBitContext gb;
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|     size_t new_size, old_size = buf ? buf->size : 0;
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|     int ret, cc_count;
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| 
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|     if (size < 3)
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|         return AVERROR_INVALIDDATA;
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| 
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|     ret = init_get_bits8(&gb, data, size);
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|     if (ret < 0)
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|         return ret;
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| 
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|     if (get_bits(&gb, 8) != 0x3) // user_data_type_code
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|         return 0;
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| 
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|     skip_bits(&gb, 1); // reserved
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|     if (!get_bits(&gb, 1)) // process_cc_data_flag
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|         return 0;
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| 
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|     skip_bits(&gb, 1); // zero bit
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|     cc_count = get_bits(&gb, 5);
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|     if (!cc_count)
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|         return 0;
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| 
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|     skip_bits(&gb, 8); // reserved
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| 
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|     /* 3 bytes per CC plus one byte marker_bits at the end */
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|     if (cc_count * 3 >= (get_bits_left(&gb) >> 3))
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|         return AVERROR_INVALIDDATA;
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| 
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|     new_size = (old_size + cc_count * 3);
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| 
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|     if (new_size > INT_MAX)
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|         return AVERROR_INVALIDDATA;
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| 
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|     /* Allow merging of the cc data from two fields. */
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|     ret = av_buffer_realloc(pbuf, new_size);
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|     if (ret < 0)
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|         return ret;
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| 
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|     buf = *pbuf;
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|     /* Use of av_buffer_realloc assumes buffer is writeable */
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|     for (int i = 0; i < cc_count; i++) {
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|         buf->data[old_size++] = get_bits(&gb, 8);
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|         buf->data[old_size++] = get_bits(&gb, 8);
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|         buf->data[old_size++] = get_bits(&gb, 8);
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|     }
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| 
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|     return cc_count;
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| }
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