blob: 85d7163c96d0595c377721d17d6b4902ec14ef02
| 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 "libavcodec/get_bits.h" |
| 23 | #include "libavcodec/golomb.h" |
| 24 | #include "avformat.h" |
| 25 | #include "rawdec.h" |
| 26 | #include "libavcodec/internal.h" |
| 27 | |
| 28 | #define MAX_SPS_COUNT 32 |
| 29 | #define MAX_PPS_COUNT 256 |
| 30 | |
| 31 | static int h264_probe(AVProbeData *p) |
| 32 | { |
| 33 | uint32_t code = -1; |
| 34 | int sps = 0, pps = 0, idr = 0, res = 0, sli = 0; |
| 35 | int i, ret; |
| 36 | int pps_ids[MAX_PPS_COUNT+1] = {0}; |
| 37 | int sps_ids[MAX_SPS_COUNT+1] = {0}; |
| 38 | unsigned pps_id, sps_id; |
| 39 | GetBitContext gb; |
| 40 | |
| 41 | for (i = 0; i + 2 < p->buf_size; i++) { |
| 42 | code = (code << 8) + p->buf[i]; |
| 43 | if ((code & 0xffffff00) == 0x100) { |
| 44 | int ref_idc = (code >> 5) & 3; |
| 45 | int type = code & 0x1F; |
| 46 | static const int8_t ref_zero[] = { |
| 47 | 2, 0, 0, 0, 0, -1, 1, -1, |
| 48 | -1, 1, 1, 1, 1, -1, 2, 2, |
| 49 | 2, 2, 2, 0, 2, 2, 2, 2, |
| 50 | 2, 2, 2, 2, 2, 2, 2, 2 |
| 51 | }; |
| 52 | |
| 53 | if (code & 0x80) // forbidden_bit |
| 54 | return 0; |
| 55 | |
| 56 | if (ref_zero[type] == 1 && ref_idc) |
| 57 | return 0; |
| 58 | if (ref_zero[type] == -1 && !ref_idc) |
| 59 | return 0; |
| 60 | if (ref_zero[type] == 2) { |
| 61 | if (!(code == 0x100 && !p->buf[i + 1] && !p->buf[i + 2])) |
| 62 | res++; |
| 63 | } |
| 64 | |
| 65 | ret = init_get_bits8(&gb, p->buf + i + 1, p->buf_size - i - 1); |
| 66 | if (ret < 0) |
| 67 | return 0; |
| 68 | |
| 69 | switch (type) { |
| 70 | case 1: |
| 71 | case 5: |
| 72 | get_ue_golomb_long(&gb); |
| 73 | if (get_ue_golomb_long(&gb) > 9U) |
| 74 | return 0; |
| 75 | pps_id = get_ue_golomb_long(&gb); |
| 76 | if (pps_id > MAX_PPS_COUNT) |
| 77 | return 0; |
| 78 | if (!pps_ids[pps_id]) |
| 79 | break; |
| 80 | |
| 81 | if (type == 1) |
| 82 | sli++; |
| 83 | else |
| 84 | idr++; |
| 85 | break; |
| 86 | case 7: |
| 87 | skip_bits(&gb, 14); |
| 88 | if (get_bits(&gb, 2)) |
| 89 | return 0; |
| 90 | skip_bits(&gb, 8); |
| 91 | sps_id = get_ue_golomb_long(&gb); |
| 92 | if (sps_id > MAX_SPS_COUNT) |
| 93 | return 0; |
| 94 | sps_ids[sps_id] = 1; |
| 95 | sps++; |
| 96 | break; |
| 97 | case 8: |
| 98 | pps_id = get_ue_golomb_long(&gb); |
| 99 | if (pps_id > MAX_PPS_COUNT) |
| 100 | return 0; |
| 101 | sps_id = get_ue_golomb_long(&gb); |
| 102 | if (sps_id > MAX_SPS_COUNT) |
| 103 | return 0; |
| 104 | if (!sps_ids[sps_id]) |
| 105 | break; |
| 106 | pps_ids[pps_id] = 1; |
| 107 | pps++; |
| 108 | break; |
| 109 | } |
| 110 | } |
| 111 | } |
| 112 | ff_tlog(NULL, "sps:%d pps:%d idr:%d sli:%d res:%d\n", sps, pps, idr, sli, res); |
| 113 | |
| 114 | if (sps && pps && (idr || sli > 3) && res < (sps + pps + idr)) |
| 115 | return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg |
| 116 | |
| 117 | return 0; |
| 118 | } |
| 119 | |
| 120 | FF_DEF_RAWVIDEO_DEMUXER(h264, "raw H.264 video", h264_probe, "h26l,h264,264,avc", AV_CODEC_ID_H264) |
| 121 |