mirror of https://git.ffmpeg.org/ffmpeg.git
55 lines
2.0 KiB
C
55 lines
2.0 KiB
C
/*
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* RAW MPEG-4 video demuxer
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* Copyright (c) 2006 Thijs Vermeir <thijs.vermeir@barco.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avformat.h"
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#include "rawdec.h"
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#define VISUAL_OBJECT_START_CODE 0x000001b5
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#define VOP_START_CODE 0x000001b6
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static int mpeg4video_probe(AVProbeData *probe_packet)
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{
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uint32_t temp_buffer= -1;
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int VO=0, VOL=0, VOP = 0, VISO = 0, res=0;
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int i;
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for(i=0; i<probe_packet->buf_size; i++){
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temp_buffer = (temp_buffer<<8) + probe_packet->buf[i];
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if (temp_buffer & 0xfffffe00)
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continue;
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if (temp_buffer < 2)
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continue;
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if (temp_buffer == VOP_START_CODE) VOP++;
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else if (temp_buffer == VISUAL_OBJECT_START_CODE) VISO++;
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else if (temp_buffer >= 0x100 && temp_buffer < 0x120) VO++;
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else if (temp_buffer >= 0x120 && temp_buffer < 0x130) VOL++;
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else if ( !(0x1AF < temp_buffer && temp_buffer < 0x1B7)
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&& !(0x1B9 < temp_buffer && temp_buffer < 0x1C4)) res++;
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}
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if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && res==0)
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return VOP+VO > 3 ? AVPROBE_SCORE_MAX/2 : AVPROBE_SCORE_MAX/4;
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return 0;
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}
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FF_DEF_RAWVIDEO_DEMUXER(m4v, "raw MPEG-4 video format", mpeg4video_probe, "m4v", CODEC_ID_MPEG4)
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