mirror of https://git.ffmpeg.org/ffmpeg.git
130 lines
4.3 KiB
C
130 lines
4.3 KiB
C
/*
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* TAK parser
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* Copyright (c) 2012 Michael Niedermayer
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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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* @file
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* TAK parser
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**/
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#define BITSTREAM_READER_LE
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#include "parser.h"
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#include "tak.h"
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typedef struct TAKParseContext {
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ParseContext pc;
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TAKStreamInfo ti;
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int index;
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} TAKParseContext;
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static av_cold int tak_init(AVCodecParserContext *s)
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{
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ff_tak_init_crc();
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return 0;
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}
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static int tak_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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TAKParseContext *t = s->priv_data;
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ParseContext *pc = &t->pc;
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int next = END_NOT_FOUND;
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GetBitContext gb;
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int consumed = 0;
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int needed = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
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if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
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TAKStreamInfo ti;
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init_get_bits(&gb, buf, buf_size);
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if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
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s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples
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: t->ti.frame_samples;
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*poutbuf = buf;
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*poutbuf_size = buf_size;
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return buf_size;
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}
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while (buf_size || t->index + needed <= pc->index) {
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if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
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int tmp_buf_size = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES,
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buf_size);
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const uint8_t *tmp_buf = buf;
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ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size);
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consumed += tmp_buf_size;
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buf += tmp_buf_size;
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buf_size -= tmp_buf_size;
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}
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for (; t->index + needed <= pc->index; t->index++)
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if (pc->buffer[t->index] == 0xFF &&
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pc->buffer[t->index + 1] == 0xA0) {
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TAKStreamInfo ti;
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init_get_bits(&gb, pc->buffer + t->index,
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8 * (pc->index - t->index));
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if (!ff_tak_decode_frame_header(avctx, &gb,
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pc->frame_start_found ? &ti
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: &t->ti,
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127) &&
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!ff_tak_check_crc(pc->buffer + t->index,
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get_bits_count(&gb) / 8)) {
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if (!pc->frame_start_found) {
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pc->frame_start_found = 1;
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s->duration = t->ti.last_frame_samples ?
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t->ti.last_frame_samples :
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t->ti.frame_samples;
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} else {
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pc->frame_start_found = 0;
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next = t->index - pc->index;
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t->index = 0;
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goto found;
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}
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}
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}
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}
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found:
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if (consumed && !buf_size && next == END_NOT_FOUND ||
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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 + consumed;
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}
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if (next != END_NOT_FOUND) {
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next += consumed;
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pc->overread = FFMAX(0, -next);
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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_tak_parser = {
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.codec_ids = { AV_CODEC_ID_TAK },
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.priv_data_size = sizeof(TAKParseContext),
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.parser_init = tak_init,
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.parser_parse = tak_parse,
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.parser_close = ff_parse_close,
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};
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