yading@10: /*
yading@10:  * DNxHD/VC-3 parser
yading@10:  * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * DNxHD/VC-3 parser
yading@10:  */
yading@10: 
yading@10: #include "parser.h"
yading@10: 
yading@10: #define DNXHD_HEADER_PREFIX 0x000002800100
yading@10: 
yading@10: typedef struct {
yading@10:     ParseContext pc;
yading@10:     int interlaced;
yading@10:     int cur_field; /* first field is 0, second is 1 */
yading@10: } DNXHDParserContext;
yading@10: 
yading@10: static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
yading@10:                                 const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     ParseContext *pc = &dctx->pc;
yading@10:     uint64_t state = pc->state64;
yading@10:     int pic_found = pc->frame_start_found;
yading@10:     int i = 0;
yading@10:     int interlaced = dctx->interlaced;
yading@10:     int cur_field = dctx->cur_field;
yading@10: 
yading@10:     if (!pic_found) {
yading@10:         for (i = 0; i < buf_size; i++) {
yading@10:             state = (state<<8) | buf[i];
yading@10:             if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
yading@10:                 i++;
yading@10:                 pic_found = 1;
yading@10:                 interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */
yading@10:                 cur_field = state&1;
yading@10:                 break;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     if (pic_found) {
yading@10:         if (!buf_size) /* EOF considered as end of frame */
yading@10:             return 0;
yading@10:         for (; i < buf_size; i++) {
yading@10:             state = (state<<8) | buf[i];
yading@10:             if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
yading@10:                 if (!interlaced || dctx->cur_field) {
yading@10:                     pc->frame_start_found = 0;
yading@10:                     pc->state64 = -1;
yading@10:                     dctx->interlaced = interlaced;
yading@10:                     dctx->cur_field = 0;
yading@10:                     return i-5;
yading@10:                 } else {
yading@10:                     /* continue, to get the second field */
yading@10:                     dctx->interlaced = interlaced = (state&2)>>1;
yading@10:                     dctx->cur_field = cur_field = state&1;
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10:     }
yading@10:     pc->frame_start_found = pic_found;
yading@10:     pc->state64 = state;
yading@10:     dctx->interlaced = interlaced;
yading@10:     dctx->cur_field = cur_field;
yading@10:     return END_NOT_FOUND;
yading@10: }
yading@10: 
yading@10: static int dnxhd_parse(AVCodecParserContext *s,
yading@10:                        AVCodecContext *avctx,
yading@10:                        const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                        const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     DNXHDParserContext *dctx = s->priv_data;
yading@10:     ParseContext *pc = &dctx->pc;
yading@10:     int next;
yading@10: 
yading@10:     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
yading@10:         next = buf_size;
yading@10:     } else {
yading@10:         next = dnxhd_find_frame_end(dctx, buf, buf_size);
yading@10:         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
yading@10:             *poutbuf = NULL;
yading@10:             *poutbuf_size = 0;
yading@10:             return buf_size;
yading@10:         }
yading@10:     }
yading@10:     *poutbuf = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_dnxhd_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_DNXHD },
yading@10:     .priv_data_size = sizeof(DNXHDParserContext),
yading@10:     .parser_parse   = dnxhd_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };