blob: aca962123bf1e749f3e85415c92ac77cf6c1c147
| 1 | /* |
| 2 | * RAW MPEG video demuxer |
| 3 | * Copyright (c) 2002-2003 Fabrice Bellard |
| 4 | * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include "avformat.h" |
| 24 | #include "rawdec.h" |
| 25 | |
| 26 | #include "libavutil/intreadwrite.h" |
| 27 | #include "libavcodec/internal.h" |
| 28 | |
| 29 | #define SEQ_START_CODE 0x000001b3 |
| 30 | #define GOP_START_CODE 0x000001b8 |
| 31 | #define PICTURE_START_CODE 0x00000100 |
| 32 | #define SLICE_START_CODE 0x00000101 |
| 33 | #define PACK_START_CODE 0x000001ba |
| 34 | #define VIDEO_ID 0x000001e0 |
| 35 | #define AUDIO_ID 0x000001c0 |
| 36 | |
| 37 | static int mpegvideo_probe(AVProbeData *p) |
| 38 | { |
| 39 | uint32_t code= -1; |
| 40 | int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0; |
| 41 | const uint8_t *ptr = p->buf, *end = ptr + p->buf_size; |
| 42 | uint32_t last = 0; |
| 43 | int j; |
| 44 | |
| 45 | while (ptr < end) { |
| 46 | ptr = avpriv_find_start_code(ptr, end, &code); |
| 47 | if ((code & 0xffffff00) == 0x100) { |
| 48 | switch(code){ |
| 49 | case SEQ_START_CODE: |
| 50 | if (!(ptr[3 + 1 + 2] & 0x20)) |
| 51 | break; |
| 52 | j = -1; |
| 53 | if (ptr[j + 8] & 2) |
| 54 | j+= 64; |
| 55 | if (j >= end - ptr) |
| 56 | break; |
| 57 | if (ptr[j + 8] & 1) |
| 58 | j+= 64; |
| 59 | if (j >= end - ptr) |
| 60 | break; |
| 61 | if (AV_RB24(ptr + j + 9) & 0xFFFFFE) |
| 62 | break; |
| 63 | seq++; |
| 64 | break; |
| 65 | case PICTURE_START_CODE: pic++; break; |
| 66 | case PACK_START_CODE: pspack++; break; |
| 67 | case 0x1b6: |
| 68 | res++; break; |
| 69 | } |
| 70 | if (code >= SLICE_START_CODE && code <= 0x1af) { |
| 71 | if (last >= SLICE_START_CODE && last <= 0x1af) { |
| 72 | if (code >= last) slice++; |
| 73 | else sicle++; |
| 74 | }else{ |
| 75 | if (code == SLICE_START_CODE) slice++; |
| 76 | else sicle++; |
| 77 | } |
| 78 | } |
| 79 | if ((code & 0x1f0) == VIDEO_ID) vpes++; |
| 80 | else if((code & 0x1e0) == AUDIO_ID) apes++; |
| 81 | last = code; |
| 82 | } |
| 83 | } |
| 84 | if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) { |
| 85 | if(vpes) return AVPROBE_SCORE_EXTENSION / 4; |
| 86 | else return pic>1 ? AVPROBE_SCORE_EXTENSION + 1 : AVPROBE_SCORE_EXTENSION / 2; // +1 for .mpg |
| 87 | } |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO) |
| 92 |