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- /*
- * DCA parser
- * Copyright (C) 2004 Gildas Bazin
- * Copyright (C) 2004 Benjamin Zores
- * Copyright (C) 2006 Benjamin Larsson
- * Copyright (C) 2007 Konstantin Shishkov
- *
- * This file is part of Libav.
- *
- * Libav is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * Libav is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
- #include "parser.h"
- #include "dca.h"
- typedef struct DCAParseContext {
- ParseContext pc;
- uint32_t lastmarker;
- int size;
- int framesize;
- int hd_pos;
- } DCAParseContext;
- #define IS_MARKER(state, i, buf, buf_size) \
- ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \
- || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \
- || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE)
- /**
- * Find the end of the current frame in the bitstream.
- * @return the position of the first byte of the next frame, or -1
- */
- static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf,
- int buf_size)
- {
- int start_found, i;
- uint32_t state;
- ParseContext *pc = &pc1->pc;
- start_found = pc->frame_start_found;
- state = pc->state;
- i = 0;
- if (!start_found) {
- for (i = 0; i < buf_size; i++) {
- state = (state << 8) | buf[i];
- if (IS_MARKER(state, i, buf, buf_size)) {
- if (pc1->lastmarker && state == pc1->lastmarker) {
- start_found = 1;
- break;
- } else if (!pc1->lastmarker) {
- start_found = 1;
- pc1->lastmarker = state;
- break;
- }
- }
- }
- }
- if (start_found) {
- for (; i < buf_size; i++) {
- pc1->size++;
- state = (state << 8) | buf[i];
- if (state == DCA_HD_MARKER && !pc1->hd_pos)
- pc1->hd_pos = pc1->size;
- if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
- if(pc1->framesize > pc1->size)
- continue;
- if(!pc1->framesize){
- pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size;
- }
- pc->frame_start_found = 0;
- pc->state = -1;
- pc1->size = 0;
- return i - 3;
- }
- }
- }
- pc->frame_start_found = start_found;
- pc->state = state;
- return END_NOT_FOUND;
- }
- static av_cold int dca_parse_init(AVCodecParserContext * s)
- {
- DCAParseContext *pc1 = s->priv_data;
- pc1->lastmarker = 0;
- return 0;
- }
- static int dca_parse(AVCodecParserContext * s,
- AVCodecContext * avctx,
- const uint8_t ** poutbuf, int *poutbuf_size,
- const uint8_t * buf, int buf_size)
- {
- DCAParseContext *pc1 = s->priv_data;
- ParseContext *pc = &pc1->pc;
- int next;
- if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
- next = buf_size;
- } else {
- next = dca_find_frame_end(pc1, buf, buf_size);
- if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
- *poutbuf = NULL;
- *poutbuf_size = 0;
- return buf_size;
- }
- }
- *poutbuf = buf;
- *poutbuf_size = buf_size;
- return next;
- }
- AVCodecParser ff_dca_parser = {
- .codec_ids = { CODEC_ID_DTS },
- .priv_data_size = sizeof(DCAParseContext),
- .parser_init = dca_parse_init,
- .parser_parse = dca_parse,
- .parser_close = ff_parse_close,
- };
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