| /* |
| * 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" |
| #include "dnxhddata.h" |
| |
| typedef struct { |
| ParseContext pc; |
| int cur_byte; |
| int remaining; |
| int w, h; |
| } 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; |
| |
| if (!pic_found) { |
| for (i = 0; i < buf_size; i++) { |
| state = (state << 8) | buf[i]; |
| if (ff_dnxhd_check_header_prefix(state & 0xffffffffff00LL) != 0) { |
| i++; |
| pic_found = 1; |
| dctx->cur_byte = 0; |
| dctx->remaining = 0; |
| break; |
| } |
| } |
| } |
| |
| if (pic_found && !dctx->remaining) { |
| if (!buf_size) /* EOF considered as end of frame */ |
| return 0; |
| for (; i < buf_size; i++) { |
| dctx->cur_byte++; |
| state = (state << 8) | buf[i]; |
| |
| if (dctx->cur_byte == 24) { |
| dctx->h = (state >> 32) & 0xFFFF; |
| } else if (dctx->cur_byte == 26) { |
| dctx->w = (state >> 32) & 0xFFFF; |
| } else if (dctx->cur_byte == 42) { |
| int cid = (state >> 32) & 0xFFFFFFFF; |
| int remaining; |
| |
| if (cid <= 0) |
| continue; |
| |
| remaining = avpriv_dnxhd_get_frame_size(cid); |
| if (remaining <= 0) { |
| remaining = avpriv_dnxhd_get_hr_frame_size(cid, dctx->w, dctx->h); |
| if (remaining <= 0) |
| continue; |
| } |
| remaining += i - 47; |
| dctx->remaining = remaining; |
| if (buf_size >= dctx->remaining) { |
| pc->frame_start_found = 0; |
| pc->state64 = -1; |
| dctx->cur_byte = 0; |
| dctx->remaining = 0; |
| return remaining; |
| } else { |
| dctx->remaining -= buf_size; |
| // Update variables for correctness, they are currently not used beyond here |
| state = -1; |
| dctx->cur_byte += buf_size - i; |
| break; |
| } |
| } |
| } |
| } else if (pic_found) { |
| if (dctx->remaining > buf_size) { |
| dctx->remaining -= buf_size; |
| } else { |
| int remaining = dctx->remaining; |
| |
| pc->frame_start_found = 0; |
| pc->state64 = -1; |
| dctx->cur_byte = 0; |
| dctx->remaining = 0; |
| return remaining; |
| } |
| } |
| pc->frame_start_found = pic_found; |
| pc->state64 = state; |
| 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, |
| }; |