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 * finds the end of the current frame in the bitstream. 34 * @return the position of the first byte of the next frame, or -1 35 */ 36static 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 76static 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 100AVCodecParser cavsvideo_parser = { 101 { CODEC_ID_CAVS }, 102 sizeof(ParseContext1), 103 NULL, 104 cavsvideo_parse, 105 ff_parse1_close, 106 ff_mpeg4video_split, 107}; 108