| 1 | /* |
| 2 | * DNxHD/VC-3 parser |
| 3 | * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * DNxHD/VC-3 parser |
| 25 | */ |
| 26 | |
| 27 | #include "parser.h" |
| 28 | |
| 29 | #define DNXHD_HEADER_PREFIX 0x000002800100 |
| 30 | |
| 31 | typedef struct { |
| 32 | ParseContext pc; |
| 33 | int interlaced; |
| 34 | int cur_field; /* first field is 0, second is 1 */ |
| 35 | } DNXHDParserContext; |
| 36 | |
| 37 | static int dnxhd_find_frame_end(DNXHDParserContext *dctx, |
| 38 | const uint8_t *buf, int buf_size) |
| 39 | { |
| 40 | ParseContext *pc = &dctx->pc; |
| 41 | uint64_t state = pc->state64; |
| 42 | int pic_found = pc->frame_start_found; |
| 43 | int i = 0; |
| 44 | int interlaced = dctx->interlaced; |
| 45 | int cur_field = dctx->cur_field; |
| 46 | |
| 47 | if (!pic_found) { |
| 48 | for (i = 0; i < buf_size; i++) { |
| 49 | state = (state << 8) | buf[i]; |
| 50 | if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) { |
| 51 | i++; |
| 52 | pic_found = 1; |
| 53 | interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */ |
| 54 | cur_field = state&1; |
| 55 | break; |
| 56 | } |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | if (pic_found) { |
| 61 | if (!buf_size) /* EOF considered as end of frame */ |
| 62 | return 0; |
| 63 | for (; i < buf_size; i++) { |
| 64 | state = (state << 8) | buf[i]; |
| 65 | if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) { |
| 66 | if (!interlaced || dctx->cur_field) { |
| 67 | pc->frame_start_found = 0; |
| 68 | pc->state64 = -1; |
| 69 | dctx->interlaced = interlaced; |
| 70 | dctx->cur_field = 0; |
| 71 | return i - 5; |
| 72 | } else { |
| 73 | /* continue, to get the second field */ |
| 74 | dctx->interlaced = interlaced = (state&2)>>1; |
| 75 | dctx->cur_field = cur_field = state&1; |
| 76 | } |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | pc->frame_start_found = pic_found; |
| 81 | pc->state64 = state; |
| 82 | dctx->interlaced = interlaced; |
| 83 | dctx->cur_field = cur_field; |
| 84 | return END_NOT_FOUND; |
| 85 | } |
| 86 | |
| 87 | static int dnxhd_parse(AVCodecParserContext *s, |
| 88 | AVCodecContext *avctx, |
| 89 | const uint8_t **poutbuf, int *poutbuf_size, |
| 90 | const uint8_t *buf, int buf_size) |
| 91 | { |
| 92 | DNXHDParserContext *dctx = s->priv_data; |
| 93 | ParseContext *pc = &dctx->pc; |
| 94 | int next; |
| 95 | |
| 96 | if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
| 97 | next = buf_size; |
| 98 | } else { |
| 99 | next = dnxhd_find_frame_end(dctx, buf, buf_size); |
| 100 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { |
| 101 | *poutbuf = NULL; |
| 102 | *poutbuf_size = 0; |
| 103 | return buf_size; |
| 104 | } |
| 105 | } |
| 106 | *poutbuf = buf; |
| 107 | *poutbuf_size = buf_size; |
| 108 | return next; |
| 109 | } |
| 110 | |
| 111 | AVCodecParser ff_dnxhd_parser = { |
| 112 | .codec_ids = { AV_CODEC_ID_DNXHD }, |
| 113 | .priv_data_size = sizeof(DNXHDParserContext), |
| 114 | .parser_parse = dnxhd_parse, |
| 115 | .parser_close = ff_parse_close, |
| 116 | }; |