| 1 | /* |
| 2 | * RAW H.264 video demuxer |
| 3 | * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> |
| 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 | #include "avformat.h" |
| 23 | #include "rawdec.h" |
| 24 | |
| 25 | static int h264_probe(AVProbeData *p) |
| 26 | { |
| 27 | uint32_t code = -1; |
| 28 | int sps = 0, pps = 0, idr = 0, res = 0, sli = 0; |
| 29 | int i; |
| 30 | |
| 31 | for (i = 0; i < p->buf_size; i++) { |
| 32 | code = (code << 8) + p->buf[i]; |
| 33 | if ((code & 0xffffff00) == 0x100) { |
| 34 | int ref_idc = (code >> 5) & 3; |
| 35 | int type = code & 0x1F; |
| 36 | static const int8_t ref_zero[] = { |
| 37 | 2, 0, 0, 0, 0, -1, 1, -1, |
| 38 | -1, 1, 1, 1, 1, -1, 2, 2, |
| 39 | 2, 2, 2, 0, 2, 2, 2, 2, |
| 40 | 2, 2, 2, 2, 2, 2, 2, 2 |
| 41 | }; |
| 42 | |
| 43 | if (code & 0x80) // forbidden_bit |
| 44 | return 0; |
| 45 | |
| 46 | if (ref_zero[type] == 1 && ref_idc) |
| 47 | return 0; |
| 48 | if (ref_zero[type] == -1 && !ref_idc) |
| 49 | return 0; |
| 50 | if (ref_zero[type] == 2) |
| 51 | res++; |
| 52 | |
| 53 | switch (type) { |
| 54 | case 1: |
| 55 | sli++; |
| 56 | break; |
| 57 | case 5: |
| 58 | idr++; |
| 59 | break; |
| 60 | case 7: |
| 61 | if (p->buf[i + 2] & 0x03) |
| 62 | return 0; |
| 63 | sps++; |
| 64 | break; |
| 65 | case 8: |
| 66 | pps++; |
| 67 | break; |
| 68 | } |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | if (sps && pps && (idr || sli > 3) && res < (sps + pps + idr)) |
| 73 | return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | FF_DEF_RAWVIDEO_DEMUXER(h264, "raw H.264 video", h264_probe, "h26l,h264,264,avc", AV_CODEC_ID_H264) |