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144 lines
4.9 KiB
144 lines
4.9 KiB
/* |
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* H.263i decoder |
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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 "mpegvideo.h" |
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#include "h263.h" |
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#include "mpegvideodata.h" |
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/* don't understand why they choose a different header ! */ |
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int ff_intel_h263_decode_picture_header(MpegEncContext *s) |
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{ |
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int format; |
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if (get_bits_left(&s->gb) == 64) { /* special dummy frames */ |
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return FRAME_SKIPPED; |
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} |
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/* picture header */ |
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if (get_bits_long(&s->gb, 22) != 0x20) { |
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av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); |
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return -1; |
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} |
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s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ |
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if (check_marker(&s->gb, "after picture_number") != 1) { |
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return -1; /* marker */ |
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} |
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if (get_bits1(&s->gb) != 0) { |
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av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n"); |
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return -1; /* h263 id */ |
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} |
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skip_bits1(&s->gb); /* split screen off */ |
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skip_bits1(&s->gb); /* camera off */ |
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skip_bits1(&s->gb); /* freeze picture release off */ |
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format = get_bits(&s->gb, 3); |
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if (format == 0 || format == 6) { |
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av_log(s->avctx, AV_LOG_ERROR, "Intel H263 free format not supported\n"); |
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return -1; |
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} |
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s->h263_plus = 0; |
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s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb); |
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s->h263_long_vectors = get_bits1(&s->gb); |
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if (get_bits1(&s->gb) != 0) { |
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av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n"); |
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return -1; /* SAC: off */ |
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} |
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s->obmc= get_bits1(&s->gb); |
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s->unrestricted_mv = s->obmc || s->h263_long_vectors; |
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s->pb_frame = get_bits1(&s->gb); |
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if (format < 6) { |
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s->width = ff_h263_format[format][0]; |
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s->height = ff_h263_format[format][1]; |
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s->avctx->sample_aspect_ratio.num = 12; |
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s->avctx->sample_aspect_ratio.den = 11; |
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} else { |
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format = get_bits(&s->gb, 3); |
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if(format == 0 || format == 7){ |
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av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n"); |
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return -1; |
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} |
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if(get_bits(&s->gb, 2)) |
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av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); |
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s->loop_filter = get_bits1(&s->gb) * !s->avctx->lowres; |
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if(get_bits1(&s->gb)) |
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av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); |
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if(get_bits1(&s->gb)) |
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s->pb_frame = 2; |
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if(get_bits(&s->gb, 5)) |
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av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); |
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if(get_bits(&s->gb, 5) != 1) |
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av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n"); |
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} |
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if(format == 6){ |
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int ar = get_bits(&s->gb, 4); |
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skip_bits(&s->gb, 9); // display width |
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check_marker(&s->gb, "in dimensions"); |
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skip_bits(&s->gb, 9); // display height |
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if(ar == 15){ |
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s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width |
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s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height |
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} else { |
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s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[ar]; |
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} |
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if (s->avctx->sample_aspect_ratio.num == 0) |
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av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n"); |
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} |
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s->chroma_qscale= s->qscale = get_bits(&s->gb, 5); |
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skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */ |
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if(s->pb_frame){ |
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skip_bits(&s->gb, 3); //temporal reference for B-frame |
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skip_bits(&s->gb, 2); //dbquant |
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} |
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/* PEI */ |
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if (skip_1stop_8data_bits(&s->gb) < 0) |
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return AVERROR_INVALIDDATA; |
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s->f_code = 1; |
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s->y_dc_scale_table= |
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s->c_dc_scale_table= ff_mpeg1_dc_scale_table; |
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ff_h263_show_pict_info(s); |
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return 0; |
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} |
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AVCodec ff_h263i_decoder = { |
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.name = "h263i", |
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.long_name = NULL_IF_CONFIG_SMALL("Intel H.263"), |
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.type = AVMEDIA_TYPE_VIDEO, |
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.id = AV_CODEC_ID_H263I, |
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.priv_data_size = sizeof(MpegEncContext), |
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.init = ff_h263_decode_init, |
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.close = ff_h263_decode_end, |
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.decode = ff_h263_decode_frame, |
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.capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, |
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.pix_fmts = (const enum AVPixelFormat[]) { |
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AV_PIX_FMT_YUV420P, |
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AV_PIX_FMT_NONE |
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}, |
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};
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