mirror of
https://github.com/FFmpeg/FFmpeg.git
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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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#include <stddef.h>
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#include <stdint.h>
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#include "atsc_a53.h"
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#include "get_bits.h"
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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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if (frame)
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side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC);
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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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*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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// 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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* '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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memcpy(sei_data + 10, side_data->data, side_data->size);
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sei_data[side_data->size+10] = 255;
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return 0;
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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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if (size < 3)
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return AVERROR(EINVAL);
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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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if (get_bits(&gb, 8) != 0x3) // user_data_type_code
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return 0;
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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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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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skip_bits(&gb, 8); // reserved
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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(EINVAL);
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new_size = (old_size + cc_count * 3);
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if (new_size > INT_MAX)
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return AVERROR(EINVAL);
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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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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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return cc_count;
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}
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