ffmpeg / libavformat / m4vdec.c @ 2ee45361
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/*
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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 & 0xffffff00) != 0x100) |
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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 < 0x120) VO++; |
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else if (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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AVInputFormat ff_m4v_demuxer = { |
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"m4v",
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NULL_IF_CONFIG_SMALL("raw MPEG-4 video format"),
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0,
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mpeg4video_probe, /** probing for MPEG-4 data */
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ff_raw_video_read_header, |
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ff_raw_read_partial_packet, |
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.flags= AVFMT_GENERIC_INDEX, |
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.extensions = "m4v",
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.value = CODEC_ID_MPEG4, |
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}; |