| /* |
| * RAW MPEG-4 video demuxer |
| * Copyright (c) 2006 Thijs Vermeir <thijs.vermeir@barco.com> |
| * |
| * 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" |
| |
| #define VOS_STARTCODE 0x1B0 |
| #define USER_DATA_STARTCODE 0x1B2 |
| #define GOP_STARTCODE 0x1B3 |
| #define VISUAL_OBJ_STARTCODE 0x1B5 |
| #define VOP_STARTCODE 0x1B6 |
| #define SLICE_STARTCODE 0x1B7 |
| #define EXT_STARTCODE 0x1B8 |
| |
| static int mpeg4video_probe(const AVProbeData *probe_packet) |
| { |
| uint32_t temp_buffer = -1; |
| int VO = 0, VOL = 0, VOP = 0, VISO = 0, res = 0; |
| int res_main = 0; |
| int i; |
| |
| for (i = 0; i < probe_packet->buf_size; i++) { |
| temp_buffer = (temp_buffer << 8) + probe_packet->buf[i]; |
| if (temp_buffer & 0xfffffe00) |
| continue; |
| if (temp_buffer < 2) |
| continue; |
| |
| if (temp_buffer == VOP_STARTCODE) |
| VOP++; |
| else if (temp_buffer == VISUAL_OBJ_STARTCODE) |
| VISO++; |
| else if (temp_buffer >= 0x100 && temp_buffer < 0x120) |
| VO++; |
| else if (temp_buffer >= 0x120 && temp_buffer < 0x130) |
| VOL++; |
| else if (temp_buffer == SLICE_STARTCODE || temp_buffer == EXT_STARTCODE) |
| res_main++; |
| else if (!(0x1AF < temp_buffer && temp_buffer < 0x1B7) && |
| !(0x1B9 < temp_buffer && temp_buffer < 0x1C4)) |
| res++; |
| } |
| |
| // res_main repesents the reserved codes within the "main" profile, they are |
| // added to the reserved ones if it appears that this is a "main" profile |
| // stream |
| if (res_main && 2*res_main < VOP) |
| res += res_main; |
| |
| if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && res == 0) |
| return VOP+VO > 4 ? AVPROBE_SCORE_EXTENSION : AVPROBE_SCORE_EXTENSION/2; |
| |
| if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && VOP+VO > 4) |
| return AVPROBE_SCORE_EXTENSION/10; |
| return 0; |
| } |
| |
| FF_DEF_RAWVIDEO_DEMUXER2(m4v, "raw MPEG-4 video", mpeg4video_probe, "m4v", |
| AV_CODEC_ID_MPEG4, AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT) |
