| 1 | /* |
| 2 | * Chinese AVS video (AVS1-P2, JiZhun profile) parser. |
| 3 | * Copyright (c) 2006 Stefan Gehrer <stefan.gehrer@gmx.de> |
| 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 | * Chinese AVS video (AVS1-P2, JiZhun profile) parser |
| 25 | * @author Stefan Gehrer <stefan.gehrer@gmx.de> |
| 26 | */ |
| 27 | |
| 28 | #include "parser.h" |
| 29 | #include "cavs.h" |
| 30 | |
| 31 | |
| 32 | /** |
| 33 | * Find the end of the current frame in the bitstream. |
| 34 | * @return the position of the first byte of the next frame, or -1 |
| 35 | */ |
| 36 | static int cavs_find_frame_end(ParseContext *pc, const uint8_t *buf, |
| 37 | int buf_size) { |
| 38 | int pic_found, i; |
| 39 | uint32_t state; |
| 40 | |
| 41 | pic_found= pc->frame_start_found; |
| 42 | state= pc->state; |
| 43 | |
| 44 | i=0; |
| 45 | if(!pic_found){ |
| 46 | for(i=0; i<buf_size; i++){ |
| 47 | state= (state<<8) | buf[i]; |
| 48 | if(state == PIC_I_START_CODE || state == PIC_PB_START_CODE){ |
| 49 | i++; |
| 50 | pic_found=1; |
| 51 | break; |
| 52 | } |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | if(pic_found){ |
| 57 | /* EOF considered as end of frame */ |
| 58 | if (buf_size == 0) |
| 59 | return 0; |
| 60 | for(; i<buf_size; i++){ |
| 61 | state= (state<<8) | buf[i]; |
| 62 | if((state&0xFFFFFF00) == 0x100){ |
| 63 | if(state > SLICE_MAX_START_CODE){ |
| 64 | pc->frame_start_found=0; |
| 65 | pc->state=-1; |
| 66 | return i-3; |
| 67 | } |
| 68 | } |
| 69 | } |
| 70 | } |
| 71 | pc->frame_start_found= pic_found; |
| 72 | pc->state= state; |
| 73 | return END_NOT_FOUND; |
| 74 | } |
| 75 | |
| 76 | static int cavsvideo_parse(AVCodecParserContext *s, |
| 77 | AVCodecContext *avctx, |
| 78 | const uint8_t **poutbuf, int *poutbuf_size, |
| 79 | const uint8_t *buf, int buf_size) |
| 80 | { |
| 81 | ParseContext *pc = s->priv_data; |
| 82 | int next; |
| 83 | |
| 84 | if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ |
| 85 | next= buf_size; |
| 86 | }else{ |
| 87 | next= cavs_find_frame_end(pc, buf, buf_size); |
| 88 | |
| 89 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { |
| 90 | *poutbuf = NULL; |
| 91 | *poutbuf_size = 0; |
| 92 | return buf_size; |
| 93 | } |
| 94 | } |
| 95 | *poutbuf = buf; |
| 96 | *poutbuf_size = buf_size; |
| 97 | return next; |
| 98 | } |
| 99 | |
| 100 | AVCodecParser ff_cavsvideo_parser = { |
| 101 | .codec_ids = { AV_CODEC_ID_CAVS }, |
| 102 | .priv_data_size = sizeof(ParseContext), |
| 103 | .parser_parse = cavsvideo_parse, |
| 104 | .parser_close = ff_parse_close, |
| 105 | .split = ff_mpeg4video_split, |
| 106 | }; |