/* * DNxHD/VC-3 parser * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr> * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * DNxHD/VC-3 parser */ #include "parser.h" #define DNXHD_HEADER_PREFIX 0x000002800100 typedef struct { ParseContext pc; int interlaced; int cur_field; /* first field is 0, second is 1 */ } DNXHDParserContext; static int dnxhd_find_frame_end(DNXHDParserContext *dctx, const uint8_t *buf, int buf_size) { ParseContext *pc = &dctx->pc; uint64_t state = pc->state64; int pic_found = pc->frame_start_found; int i = 0; int interlaced = dctx->interlaced; int cur_field = dctx->cur_field; if (!pic_found) { for (i = 0; i < buf_size; i++) { state = (state<<8) | buf[i]; if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) { i++; pic_found = 1; interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */ cur_field = state&1; break; } } } if (pic_found) { if (!buf_size) /* EOF considered as end of frame */ return 0; for (; i < buf_size; i++) { state = (state<<8) | buf[i]; if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) { if (!interlaced || dctx->cur_field) { pc->frame_start_found = 0; pc->state64 = -1; dctx->interlaced = interlaced; dctx->cur_field = 0; return i-5; } else { /* continue, to get the second field */ dctx->interlaced = interlaced = (state&2)>>1; dctx->cur_field = cur_field = state&1; } } } } pc->frame_start_found = pic_found; pc->state64 = state; dctx->interlaced = interlaced; dctx->cur_field = cur_field; return END_NOT_FOUND; } static int dnxhd_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size) { DNXHDParserContext *dctx = s->priv_data; ParseContext *pc = &dctx->pc; int next; if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { next = buf_size; } else { next = dnxhd_find_frame_end(dctx, 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_dnxhd_parser = { .codec_ids = { AV_CODEC_ID_DNXHD }, .priv_data_size = sizeof(DNXHDParserContext), .parser_parse = dnxhd_parse, .parser_close = ff_parse_close, };