annotate ffmpeg/libavcodec/dnxhd_parser.c @ 13:844d341cf643 tip

Back up before ISMIR
author Yading Song <yading.song@eecs.qmul.ac.uk>
date Thu, 31 Oct 2013 13:17:06 +0000
parents 6840f77b83aa
children
rev   line source
yading@10 1 /*
yading@10 2 * DNxHD/VC-3 parser
yading@10 3 * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
yading@10 4 *
yading@10 5 * This file is part of FFmpeg.
yading@10 6 *
yading@10 7 * FFmpeg is free software; you can redistribute it and/or
yading@10 8 * modify it under the terms of the GNU Lesser General Public
yading@10 9 * License as published by the Free Software Foundation; either
yading@10 10 * version 2.1 of the License, or (at your option) any later version.
yading@10 11 *
yading@10 12 * FFmpeg is distributed in the hope that it will be useful,
yading@10 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
yading@10 15 * Lesser General Public License for more details.
yading@10 16 *
yading@10 17 * You should have received a copy of the GNU Lesser General Public
yading@10 18 * License along with FFmpeg; if not, write to the Free Software
yading@10 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10 20 */
yading@10 21
yading@10 22 /**
yading@10 23 * @file
yading@10 24 * DNxHD/VC-3 parser
yading@10 25 */
yading@10 26
yading@10 27 #include "parser.h"
yading@10 28
yading@10 29 #define DNXHD_HEADER_PREFIX 0x000002800100
yading@10 30
yading@10 31 typedef struct {
yading@10 32 ParseContext pc;
yading@10 33 int interlaced;
yading@10 34 int cur_field; /* first field is 0, second is 1 */
yading@10 35 } DNXHDParserContext;
yading@10 36
yading@10 37 static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
yading@10 38 const uint8_t *buf, int buf_size)
yading@10 39 {
yading@10 40 ParseContext *pc = &dctx->pc;
yading@10 41 uint64_t state = pc->state64;
yading@10 42 int pic_found = pc->frame_start_found;
yading@10 43 int i = 0;
yading@10 44 int interlaced = dctx->interlaced;
yading@10 45 int cur_field = dctx->cur_field;
yading@10 46
yading@10 47 if (!pic_found) {
yading@10 48 for (i = 0; i < buf_size; i++) {
yading@10 49 state = (state<<8) | buf[i];
yading@10 50 if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
yading@10 51 i++;
yading@10 52 pic_found = 1;
yading@10 53 interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */
yading@10 54 cur_field = state&1;
yading@10 55 break;
yading@10 56 }
yading@10 57 }
yading@10 58 }
yading@10 59
yading@10 60 if (pic_found) {
yading@10 61 if (!buf_size) /* EOF considered as end of frame */
yading@10 62 return 0;
yading@10 63 for (; i < buf_size; i++) {
yading@10 64 state = (state<<8) | buf[i];
yading@10 65 if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
yading@10 66 if (!interlaced || dctx->cur_field) {
yading@10 67 pc->frame_start_found = 0;
yading@10 68 pc->state64 = -1;
yading@10 69 dctx->interlaced = interlaced;
yading@10 70 dctx->cur_field = 0;
yading@10 71 return i-5;
yading@10 72 } else {
yading@10 73 /* continue, to get the second field */
yading@10 74 dctx->interlaced = interlaced = (state&2)>>1;
yading@10 75 dctx->cur_field = cur_field = state&1;
yading@10 76 }
yading@10 77 }
yading@10 78 }
yading@10 79 }
yading@10 80 pc->frame_start_found = pic_found;
yading@10 81 pc->state64 = state;
yading@10 82 dctx->interlaced = interlaced;
yading@10 83 dctx->cur_field = cur_field;
yading@10 84 return END_NOT_FOUND;
yading@10 85 }
yading@10 86
yading@10 87 static int dnxhd_parse(AVCodecParserContext *s,
yading@10 88 AVCodecContext *avctx,
yading@10 89 const uint8_t **poutbuf, int *poutbuf_size,
yading@10 90 const uint8_t *buf, int buf_size)
yading@10 91 {
yading@10 92 DNXHDParserContext *dctx = s->priv_data;
yading@10 93 ParseContext *pc = &dctx->pc;
yading@10 94 int next;
yading@10 95
yading@10 96 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
yading@10 97 next = buf_size;
yading@10 98 } else {
yading@10 99 next = dnxhd_find_frame_end(dctx, buf, buf_size);
yading@10 100 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
yading@10 101 *poutbuf = NULL;
yading@10 102 *poutbuf_size = 0;
yading@10 103 return buf_size;
yading@10 104 }
yading@10 105 }
yading@10 106 *poutbuf = buf;
yading@10 107 *poutbuf_size = buf_size;
yading@10 108 return next;
yading@10 109 }
yading@10 110
yading@10 111 AVCodecParser ff_dnxhd_parser = {
yading@10 112 .codec_ids = { AV_CODEC_ID_DNXHD },
yading@10 113 .priv_data_size = sizeof(DNXHDParserContext),
yading@10 114 .parser_parse = dnxhd_parse,
yading@10 115 .parser_close = ff_parse_close,
yading@10 116 };