| /* |
| * RAW MPEG video demuxer |
| * Copyright (c) 2002-2003 Fabrice Bellard |
| * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "avformat.h" |
| #include "rawdec.h" |
| |
| #include "libavutil/intreadwrite.h" |
| #include "libavcodec/internal.h" |
| |
| #define SEQ_START_CODE 0x000001b3 |
| #define GOP_START_CODE 0x000001b8 |
| #define PICTURE_START_CODE 0x00000100 |
| #define SLICE_START_CODE 0x00000101 |
| #define PACK_START_CODE 0x000001ba |
| #define VIDEO_ID 0x000001e0 |
| #define AUDIO_ID 0x000001c0 |
| |
| static int mpegvideo_probe(AVProbeData *p) |
| { |
| uint32_t code= -1; |
| int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0; |
| const uint8_t *ptr = p->buf, *end = ptr + p->buf_size; |
| uint32_t last = 0; |
| int j; |
| |
| while (ptr < end) { |
| ptr = avpriv_find_start_code(ptr, end, &code); |
| if ((code & 0xffffff00) == 0x100) { |
| switch(code){ |
| case SEQ_START_CODE: |
| if (!(ptr[3 + 1 + 2] & 0x20)) |
| break; |
| j = -1; |
| if (ptr[j + 8] & 2) |
| j+= 64; |
| if (j >= end - ptr) |
| break; |
| if (ptr[j + 8] & 1) |
| j+= 64; |
| if (j >= end - ptr) |
| break; |
| if (AV_RB24(ptr + j + 9) & 0xFFFFFE) |
| break; |
| seq++; |
| break; |
| case PICTURE_START_CODE: pic++; break; |
| case PACK_START_CODE: pspack++; break; |
| case 0x1b6: |
| res++; break; |
| } |
| if (code >= SLICE_START_CODE && code <= 0x1af) { |
| if (last >= SLICE_START_CODE && last <= 0x1af) { |
| if (code >= last) slice++; |
| else sicle++; |
| }else{ |
| if (code == SLICE_START_CODE) slice++; |
| else sicle++; |
| } |
| } |
| if ((code & 0x1f0) == VIDEO_ID) vpes++; |
| else if((code & 0x1e0) == AUDIO_ID) apes++; |
| last = code; |
| } |
| } |
| if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) { |
| if(vpes) return AVPROBE_SCORE_EXTENSION / 4; |
| else return pic>1 ? AVPROBE_SCORE_EXTENSION + 1 : AVPROBE_SCORE_EXTENSION / 2; // +1 for .mpg |
| } |
| return 0; |
| } |
| |
| FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO) |
