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120 lines
3.9 KiB
120 lines
3.9 KiB
/* |
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* RAW H.264 video demuxer |
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* Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> |
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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 "libavcodec/get_bits.h" |
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#include "libavcodec/golomb.h" |
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#include "avformat.h" |
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#include "rawdec.h" |
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#include "libavcodec/internal.h" |
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#define MAX_SPS_COUNT 32 |
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#define MAX_PPS_COUNT 256 |
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static int h264_probe(const AVProbeData *p) |
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{ |
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uint32_t code = -1; |
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int sps = 0, pps = 0, idr = 0, res = 0, sli = 0; |
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int i, ret; |
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int pps_ids[MAX_PPS_COUNT+1] = {0}; |
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int sps_ids[MAX_SPS_COUNT+1] = {0}; |
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unsigned pps_id, sps_id; |
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GetBitContext gb; |
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for (i = 0; i + 2 < p->buf_size; i++) { |
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code = (code << 8) + p->buf[i]; |
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if ((code & 0xffffff00) == 0x100) { |
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int ref_idc = (code >> 5) & 3; |
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int type = code & 0x1F; |
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static const int8_t ref_zero[] = { |
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2, 0, 0, 0, 0, -1, 1, -1, |
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-1, 1, 1, 1, 1, -1, 2, 2, |
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2, 2, 2, 0, 2, 2, 2, 2, |
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2, 2, 2, 2, 2, 2, 2, 2 |
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}; |
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if (code & 0x80) // forbidden_bit |
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return 0; |
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if (ref_zero[type] == 1 && ref_idc) |
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return 0; |
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if (ref_zero[type] == -1 && !ref_idc) |
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return 0; |
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if (ref_zero[type] == 2) { |
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if (!(code == 0x100 && !p->buf[i + 1] && !p->buf[i + 2])) |
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res++; |
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} |
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ret = init_get_bits8(&gb, p->buf + i + 1, p->buf_size - i - 1); |
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if (ret < 0) |
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return 0; |
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switch (type) { |
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case 1: |
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case 5: |
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get_ue_golomb_long(&gb); |
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if (get_ue_golomb_long(&gb) > 9U) |
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return 0; |
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pps_id = get_ue_golomb_long(&gb); |
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if (pps_id > MAX_PPS_COUNT) |
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return 0; |
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if (!pps_ids[pps_id]) |
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break; |
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if (type == 1) |
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sli++; |
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else |
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idr++; |
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break; |
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case 7: |
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skip_bits(&gb, 14); |
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if (get_bits(&gb, 2)) |
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return 0; |
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skip_bits(&gb, 8); |
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sps_id = get_ue_golomb_long(&gb); |
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if (sps_id > MAX_SPS_COUNT) |
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return 0; |
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sps_ids[sps_id] = 1; |
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sps++; |
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break; |
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case 8: |
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pps_id = get_ue_golomb_long(&gb); |
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if (pps_id > MAX_PPS_COUNT) |
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return 0; |
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sps_id = get_ue_golomb_long(&gb); |
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if (sps_id > MAX_SPS_COUNT) |
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return 0; |
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if (!sps_ids[sps_id]) |
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break; |
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pps_ids[pps_id] = 1; |
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pps++; |
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break; |
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} |
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} |
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} |
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ff_tlog(NULL, "sps:%d pps:%d idr:%d sli:%d res:%d\n", sps, pps, idr, sli, res); |
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if (sps && pps && (idr || sli > 3) && res < (sps + pps + idr)) |
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return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg |
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return 0; |
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} |
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FF_DEF_RAWVIDEO_DEMUXER(h264, "raw H.264 video", h264_probe, "h26l,h264,264,avc", AV_CODEC_ID_H264)
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