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/* |
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* AVS2-P2/IEEE1857.4 video parser. |
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* Copyright (c) 2018 Huiwen Ren <hwrenx@gmail.com> |
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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 "parser.h" |
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#define SLICE_MAX_START_CODE 0x000001af |
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#define ISPIC(x) ((x) == 0xB3 || (x) == 0xB6) |
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#define ISUNIT(x) ((x) == 0xB0 || (x) == 0xB1 || (x) == 0xB2 || ISPIC(x)) |
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static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size) |
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{ |
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int pic_found = pc->frame_start_found; |
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uint32_t state = pc->state; |
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int cur = 0; |
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if (!pic_found) { |
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for (; cur < buf_size; ++cur) { |
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state = (state<<8) | buf[cur]; |
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if (ISUNIT(buf[cur])){ |
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++cur; |
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pic_found = 1; |
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break; |
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} |
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} |
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} |
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if (pic_found) { |
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if (!buf_size) |
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return END_NOT_FOUND; |
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for (; cur < buf_size; ++cur) { |
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state = (state << 8) | buf[cur]; |
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if ((state & 0xFFFFFF00) == 0x100 && state > SLICE_MAX_START_CODE) { |
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pc->frame_start_found = 0; |
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pc->state = -1; |
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return cur - 3; |
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} |
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} |
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} |
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pc->frame_start_found = pic_found; |
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pc->state = state; |
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return END_NOT_FOUND; |
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} |
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static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx, |
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const uint8_t **poutbuf, int *poutbuf_size, |
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const uint8_t *buf, int buf_size) |
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{ |
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ParseContext *pc = s->priv_data; |
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int next; |
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if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
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next = buf_size; |
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} else { |
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next = avs2_find_frame_end(pc, buf, buf_size); |
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if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { |
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*poutbuf = NULL; |
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*poutbuf_size = 0; |
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return buf_size; |
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} |
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} |
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*poutbuf = buf; |
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*poutbuf_size = buf_size; |
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return next; |
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} |
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AVCodecParser ff_avs2_parser = { |
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.codec_ids = { AV_CODEC_ID_AVS2 }, |
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.priv_data_size = sizeof(ParseContext), |
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.parser_parse = avs2_parse, |
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.parser_close = ff_parse_close, |
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.split = ff_mpeg4video_split, |
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}; |