yading@11: /*
yading@11:  * RAW MPEG-4 video demuxer
yading@11:  * Copyright (c) 2006  Thijs Vermeir <thijs.vermeir@barco.com>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "rawdec.h"
yading@11: 
yading@11: #define VISUAL_OBJECT_START_CODE       0x000001b5
yading@11: #define VOP_START_CODE                 0x000001b6
yading@11: 
yading@11: static int mpeg4video_probe(AVProbeData *probe_packet)
yading@11: {
yading@11:     uint32_t temp_buffer= -1;
yading@11:     int VO=0, VOL=0, VOP = 0, VISO = 0, res=0;
yading@11:     int i;
yading@11: 
yading@11:     for(i=0; i<probe_packet->buf_size; i++){
yading@11:         temp_buffer = (temp_buffer<<8) + probe_packet->buf[i];
yading@11:         if ((temp_buffer & 0xffffff00) != 0x100)
yading@11:             continue;
yading@11: 
yading@11:         if (temp_buffer == VOP_START_CODE)                         VOP++;
yading@11:         else if (temp_buffer == VISUAL_OBJECT_START_CODE)          VISO++;
yading@11:         else if (temp_buffer < 0x120)                              VO++;
yading@11:         else if (temp_buffer < 0x130)                              VOL++;
yading@11:         else if (   !(0x1AF < temp_buffer && temp_buffer < 0x1B7)
yading@11:                  && !(0x1B9 < temp_buffer && temp_buffer < 0x1C4)) res++;
yading@11:     }
yading@11: 
yading@11:     if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && res==0)
yading@11:         return VOP+VO > 3 ? AVPROBE_SCORE_MAX/2 : AVPROBE_SCORE_MAX/4;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: FF_DEF_RAWVIDEO_DEMUXER(m4v, "raw MPEG-4 video", mpeg4video_probe, "m4v", AV_CODEC_ID_MPEG4)