2007-05-21 15:51:29 +03:00
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/*
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2016-04-27 19:45:23 +02:00
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* H.261 decoder
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2007-05-21 15:51:29 +03:00
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* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
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* Copyright (c) 2004 Maarten Daniels
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*
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2011-03-18 19:35:10 +02:00
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* This file is part of Libav.
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2007-05-21 15:51:29 +03:00
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*
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2011-03-18 19:35:10 +02:00
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* Libav is free software; you can redistribute it and/or
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2007-05-21 15:51:29 +03:00
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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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2011-03-18 19:35:10 +02:00
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* Libav is distributed in the hope that it will be useful,
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2007-05-21 15:51:29 +03:00
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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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2011-03-18 19:35:10 +02:00
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* License along with Libav; if not, write to the Free Software
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2007-05-21 15:51:29 +03:00
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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2010-04-20 17:45:34 +03:00
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* @file
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2007-05-21 15:51:29 +03:00
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* H.261 decoder.
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*/
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#include "avcodec.h"
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2016-04-10 11:44:20 +02:00
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#include "bitstream.h"
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2014-06-20 16:05:45 +03:00
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#include "mpeg_er.h"
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2014-02-28 15:40:54 +03:00
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#include "mpegutils.h"
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2007-05-21 15:51:29 +03:00
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#include "mpegvideo.h"
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2010-02-06 14:53:28 +02:00
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#include "h263.h"
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2007-05-21 15:51:29 +03:00
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#include "h261.h"
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2013-10-27 12:02:26 +03:00
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#include "internal.h"
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2016-04-10 11:44:20 +02:00
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#include "vlc.h"
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2007-05-21 15:51:29 +03:00
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#define H261_MBA_VLC_BITS 9
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#define H261_MTYPE_VLC_BITS 6
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#define H261_MV_VLC_BITS 7
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#define H261_CBP_VLC_BITS 9
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#define TCOEFF_VLC_BITS 9
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#define MBA_STUFFING 33
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#define MBA_STARTCODE 34
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static VLC h261_mba_vlc;
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static VLC h261_mtype_vlc;
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static VLC h261_mv_vlc;
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static VLC h261_cbp_vlc;
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2013-04-04 15:31:58 +03:00
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static av_cold void h261_decode_init_vlc(H261Context *h)
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{
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2007-05-21 15:51:29 +03:00
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static int done = 0;
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2013-04-04 15:31:58 +03:00
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if (!done) {
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2007-05-21 15:51:29 +03:00
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done = 1;
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2009-04-11 16:58:18 +03:00
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INIT_VLC_STATIC(&h261_mba_vlc, H261_MBA_VLC_BITS, 35,
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2013-04-04 15:56:01 +03:00
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ff_h261_mba_bits, 1, 1,
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ff_h261_mba_code, 1, 1, 662);
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2009-04-11 16:58:18 +03:00
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INIT_VLC_STATIC(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
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2013-04-04 15:56:01 +03:00
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ff_h261_mtype_bits, 1, 1,
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ff_h261_mtype_code, 1, 1, 80);
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2009-04-11 16:58:18 +03:00
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INIT_VLC_STATIC(&h261_mv_vlc, H261_MV_VLC_BITS, 17,
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2013-04-04 15:56:01 +03:00
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&ff_h261_mv_tab[0][1], 2, 1,
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&ff_h261_mv_tab[0][0], 2, 1, 144);
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2009-04-11 16:58:18 +03:00
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INIT_VLC_STATIC(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
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2013-04-04 15:56:01 +03:00
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&ff_h261_cbp_tab[0][1], 2, 1,
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&ff_h261_cbp_tab[0][0], 2, 1, 512);
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INIT_VLC_RL(ff_h261_rl_tcoeff, 552);
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2007-05-21 15:51:29 +03:00
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}
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}
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2013-04-04 15:31:58 +03:00
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static av_cold int h261_decode_init(AVCodecContext *avctx)
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{
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H261Context *h = avctx->priv_data;
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MpegEncContext *const s = &h->s;
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2007-05-21 15:51:29 +03:00
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// set defaults
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2014-08-10 18:25:12 +03:00
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ff_mpv_decode_defaults(s);
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2013-04-04 15:31:58 +03:00
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s->avctx = avctx;
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s->width = s->avctx->coded_width;
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s->height = s->avctx->coded_height;
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s->codec_id = s->avctx->codec->id;
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s->out_format = FMT_H261;
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s->low_delay = 1;
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avctx->pix_fmt = AV_PIX_FMT_YUV420P;
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s->codec_id = avctx->codec->id;
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2007-05-21 15:51:29 +03:00
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2013-04-06 00:43:31 +03:00
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ff_h261_common_init();
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2007-05-21 15:51:29 +03:00
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h261_decode_init_vlc(h);
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h->gob_start_code_skipped = 0;
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return 0;
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}
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/**
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2011-12-07 15:03:53 +03:00
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* Decode the group of blocks header or slice header.
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2008-03-22 03:06:57 +02:00
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* @return <0 if an error occurred
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2007-05-21 15:51:29 +03:00
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*/
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2013-04-04 15:31:58 +03:00
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static int h261_decode_gob_header(H261Context *h)
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{
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2007-05-21 15:51:29 +03:00
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unsigned int val;
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2013-04-04 15:31:58 +03:00
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MpegEncContext *const s = &h->s;
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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if (!h->gob_start_code_skipped) {
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2007-05-21 15:51:29 +03:00
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/* Check for GOB Start Code */
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2016-04-10 11:44:20 +02:00
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val = bitstream_peek(&s->bc, 15);
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2013-04-04 15:31:58 +03:00
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if (val)
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2007-05-21 15:51:29 +03:00
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return -1;
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/* We have a GBSC */
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2016-04-10 11:44:20 +02:00
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bitstream_skip(&s->bc, 16);
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2007-05-21 15:51:29 +03:00
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}
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h->gob_start_code_skipped = 0;
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2016-04-10 11:44:20 +02:00
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h->gob_number = bitstream_read(&s->bc, 4); /* GN */
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s->qscale = bitstream_read(&s->bc, 5); /* GQUANT */
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2007-05-21 15:51:29 +03:00
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/* Check if gob_number is valid */
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2013-04-04 15:31:58 +03:00
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if (s->mb_height == 18) { // CIF
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if ((h->gob_number <= 0) || (h->gob_number > 12))
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2007-05-21 15:51:29 +03:00
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return -1;
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2013-04-04 15:31:58 +03:00
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} else { // QCIF
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if ((h->gob_number != 1) && (h->gob_number != 3) &&
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(h->gob_number != 5))
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2007-05-21 15:51:29 +03:00
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return -1;
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}
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/* GEI */
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2016-04-10 11:44:20 +02:00
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while (bitstream_read_bit(&s->bc) != 0)
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bitstream_skip(&s->bc, 8);
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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if (s->qscale == 0) {
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2008-08-03 01:51:49 +03:00
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av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n");
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2011-10-22 15:44:16 +03:00
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if (s->avctx->err_recognition & AV_EF_BITSTREAM)
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2008-08-03 01:51:49 +03:00
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return -1;
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}
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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/* For the first transmitted macroblock in a GOB, MBA is the absolute
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* address. For subsequent macroblocks, MBA is the difference between
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* the absolute addresses of the macroblock and the last transmitted
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* macroblock. */
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2007-05-21 15:51:29 +03:00
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h->current_mba = 0;
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2013-04-04 15:31:58 +03:00
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h->mba_diff = 0;
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2007-05-21 15:51:29 +03:00
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return 0;
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}
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/**
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2011-12-07 15:03:53 +03:00
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* Decode the group of blocks / video packet header.
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2007-05-21 15:51:29 +03:00
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* @return <0 if no resync found
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*/
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2013-04-20 22:51:11 +03:00
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static int h261_resync(H261Context *h)
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2013-04-04 15:31:58 +03:00
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{
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MpegEncContext *const s = &h->s;
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2007-05-21 15:51:29 +03:00
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int left, ret;
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2013-04-04 15:31:58 +03:00
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if (h->gob_start_code_skipped) {
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ret = h261_decode_gob_header(h);
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if (ret >= 0)
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2007-05-21 15:51:29 +03:00
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return 0;
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2013-04-04 15:31:58 +03:00
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} else {
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2016-04-10 11:44:20 +02:00
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if (bitstream_peek(&s->bc, 15) == 0) {
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2013-04-04 15:31:58 +03:00
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ret = h261_decode_gob_header(h);
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if (ret >= 0)
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2007-05-21 15:51:29 +03:00
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return 0;
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}
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2013-04-04 15:31:58 +03:00
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// OK, it is not where it is supposed to be ...
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2016-04-10 11:44:20 +02:00
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s->bc = s->last_resync_bc;
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bitstream_align(&s->bc);
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left = bitstream_bits_left(&s->bc);
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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for (; left > 15 + 1 + 4 + 5; left -= 8) {
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2016-04-10 11:44:20 +02:00
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if (bitstream_peek(&s->bc, 15) == 0) {
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BitstreamContext bak = s->bc;
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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ret = h261_decode_gob_header(h);
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if (ret >= 0)
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2007-05-21 15:51:29 +03:00
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return 0;
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2016-04-10 11:44:20 +02:00
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s->bc = bak;
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2007-05-21 15:51:29 +03:00
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}
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2016-04-10 11:44:20 +02:00
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bitstream_skip(&s->bc, 8);
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2007-05-21 15:51:29 +03:00
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}
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}
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return -1;
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}
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/**
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2011-12-07 15:03:53 +03:00
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* Decode skipped macroblocks.
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2007-05-21 15:51:29 +03:00
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* @return 0
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*/
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2013-04-04 15:31:58 +03:00
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static int h261_decode_mb_skipped(H261Context *h, int mba1, int mba2)
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2007-05-21 15:51:29 +03:00
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{
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2013-04-04 15:31:58 +03:00
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MpegEncContext *const s = &h->s;
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2007-05-21 15:51:29 +03:00
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int i;
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s->mb_intra = 0;
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2013-04-04 15:31:58 +03:00
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for (i = mba1; i < mba2; i++) {
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2007-05-21 15:51:29 +03:00
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int j, xy;
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2013-04-04 15:31:58 +03:00
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s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11;
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s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11;
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xy = s->mb_x + s->mb_y * s->mb_stride;
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2007-05-21 15:51:29 +03:00
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ff_init_block_index(s);
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ff_update_block_index(s);
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2013-04-04 15:31:58 +03:00
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for (j = 0; j < 6; j++)
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2007-05-21 15:51:29 +03:00
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s->block_last_index[j] = -1;
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2013-04-04 15:31:58 +03:00
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s->mv_dir = MV_DIR_FORWARD;
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s->mv_type = MV_TYPE_16X16;
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2012-11-21 23:34:46 +03:00
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s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
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2013-04-04 15:31:58 +03:00
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s->mv[0][0][0] = 0;
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s->mv[0][0][1] = 0;
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s->mb_skipped = 1;
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h->mtype &= ~MB_TYPE_H261_FIL;
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2007-05-21 15:51:29 +03:00
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2014-08-10 18:25:12 +03:00
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ff_mpv_decode_mb(s, s->block);
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2007-05-21 15:51:29 +03:00
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}
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return 0;
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}
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2013-04-04 15:34:38 +03:00
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static const int mvmap[17] = {
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0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15, -16
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};
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2016-04-10 11:44:20 +02:00
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static int decode_mv_component(BitstreamContext *bc, int v)
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2013-04-04 15:31:58 +03:00
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{
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2016-04-10 11:44:20 +02:00
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int mv_diff = bitstream_read_vlc(bc, h261_mv_vlc.table, H261_MV_VLC_BITS, 2);
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2007-05-21 15:51:29 +03:00
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/* check if mv_diff is valid */
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2013-04-04 15:31:58 +03:00
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if (mv_diff < 0)
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2007-05-21 15:51:29 +03:00
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return v;
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mv_diff = mvmap[mv_diff];
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2016-04-10 11:44:20 +02:00
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if (mv_diff && !bitstream_read_bit(bc))
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2013-04-04 15:31:58 +03:00
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mv_diff = -mv_diff;
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2007-05-21 15:51:29 +03:00
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v += mv_diff;
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2013-04-04 15:31:58 +03:00
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if (v <= -16)
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v += 32;
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else if (v >= 16)
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v -= 32;
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2007-05-21 15:51:29 +03:00
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return v;
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}
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2013-04-04 15:33:55 +03:00
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/**
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* Decode a macroblock.
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* @return <0 if an error occurred
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*/
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static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
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{
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MpegEncContext *const s = &h->s;
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int code, level, i, j, run;
|
2013-04-04 15:56:01 +03:00
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RLTable *rl = &ff_h261_rl_tcoeff;
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2013-04-04 15:33:55 +03:00
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const uint8_t *scan_table;
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/* For the variable length encoding there are two code tables, one being
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* used for the first transmitted LEVEL in INTER, INTER + MC and
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* INTER + MC + FIL blocks, the second for all other LEVELs except the
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* first one in INTRA blocks which is fixed length coded with 8 bits.
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* NOTE: The two code tables only differ in one VLC so we handle that
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* manually. */
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scan_table = s->intra_scantable.permutated;
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|
|
if (s->mb_intra) {
|
|
|
|
/* DC coef */
|
2016-04-10 11:44:20 +02:00
|
|
|
level = bitstream_read(&s->bc, 8);
|
2013-04-04 15:33:55 +03:00
|
|
|
// 0 (00000000b) and -128 (10000000b) are FORBIDDEN
|
|
|
|
if ((level & 0x7F) == 0) {
|
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
|
|
|
|
level, s->mb_x, s->mb_y);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
/* The code 1000 0000 is not used, the reconstruction level of 1024
|
|
|
|
* being coded as 1111 1111. */
|
|
|
|
if (level == 255)
|
|
|
|
level = 128;
|
|
|
|
block[0] = level;
|
|
|
|
i = 1;
|
|
|
|
} else if (coded) {
|
|
|
|
// Run Level Code
|
|
|
|
// EOB Not possible for first level when cbp is available (that's why the table is different)
|
|
|
|
// 0 1 1s
|
|
|
|
// * * 0*
|
2016-04-10 11:44:20 +02:00
|
|
|
int check = bitstream_peek(&s->bc, 2);
|
2013-04-04 15:33:55 +03:00
|
|
|
i = 0;
|
|
|
|
if (check & 0x2) {
|
2016-04-10 11:44:20 +02:00
|
|
|
bitstream_skip(&s->bc, 2);
|
2013-04-04 15:33:55 +03:00
|
|
|
block[0] = (check & 0x1) ? -1 : 1;
|
|
|
|
i = 1;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
i = 0;
|
|
|
|
}
|
|
|
|
if (!coded) {
|
|
|
|
s->block_last_index[n] = i - 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
for (;;) {
|
2016-04-10 11:44:20 +02:00
|
|
|
code = bitstream_read_vlc(&s->bc, rl->vlc.table, TCOEFF_VLC_BITS, 2);
|
2013-04-04 15:33:55 +03:00
|
|
|
if (code < 0) {
|
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
|
|
|
|
s->mb_x, s->mb_y);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
if (code == rl->n) {
|
|
|
|
/* escape */
|
|
|
|
/* The remaining combinations of (run, level) are encoded with a
|
|
|
|
* 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
|
|
|
|
* level. */
|
2016-04-10 11:44:20 +02:00
|
|
|
run = bitstream_read(&s->bc, 6);
|
|
|
|
level = bitstream_read_signed(&s->bc, 8);
|
2013-04-04 15:33:55 +03:00
|
|
|
} else if (code == 0) {
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
run = rl->table_run[code];
|
|
|
|
level = rl->table_level[code];
|
2016-04-10 11:44:20 +02:00
|
|
|
if (bitstream_read_bit(&s->bc))
|
2013-04-04 15:33:55 +03:00
|
|
|
level = -level;
|
|
|
|
}
|
|
|
|
i += run;
|
|
|
|
if (i >= 64) {
|
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
|
|
|
|
s->mb_x, s->mb_y);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
j = scan_table[i];
|
|
|
|
block[j] = level;
|
|
|
|
i++;
|
|
|
|
}
|
|
|
|
s->block_last_index[n] = i - 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
static int h261_decode_mb(H261Context *h)
|
|
|
|
{
|
|
|
|
MpegEncContext *const s = &h->s;
|
2007-05-21 15:51:29 +03:00
|
|
|
int i, cbp, xy;
|
|
|
|
|
|
|
|
cbp = 63;
|
|
|
|
// Read mba
|
2013-04-04 15:31:58 +03:00
|
|
|
do {
|
2016-04-10 11:44:20 +02:00
|
|
|
h->mba_diff = bitstream_read_vlc(&s->bc, h261_mba_vlc.table,
|
|
|
|
H261_MBA_VLC_BITS, 2);
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
/* Check for slice end */
|
|
|
|
/* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
|
2013-04-04 15:31:58 +03:00
|
|
|
if (h->mba_diff == MBA_STARTCODE) { // start code
|
2007-05-21 15:51:29 +03:00
|
|
|
h->gob_start_code_skipped = 1;
|
|
|
|
return SLICE_END;
|
|
|
|
}
|
2013-04-04 15:31:58 +03:00
|
|
|
} while (h->mba_diff == MBA_STUFFING); // stuffing
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
if (h->mba_diff < 0) {
|
2016-04-10 11:44:20 +02:00
|
|
|
if (bitstream_bits_left(&s->bc) <= 7)
|
2007-05-21 15:51:29 +03:00
|
|
|
return SLICE_END;
|
|
|
|
|
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
|
|
|
|
return SLICE_ERROR;
|
|
|
|
}
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
h->mba_diff += 1;
|
2007-05-21 15:51:29 +03:00
|
|
|
h->current_mba += h->mba_diff;
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
if (h->current_mba > MBA_STUFFING)
|
2007-05-21 15:51:29 +03:00
|
|
|
return SLICE_ERROR;
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11);
|
|
|
|
s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11);
|
|
|
|
xy = s->mb_x + s->mb_y * s->mb_stride;
|
2007-05-21 15:51:29 +03:00
|
|
|
ff_init_block_index(s);
|
|
|
|
ff_update_block_index(s);
|
|
|
|
|
|
|
|
// Read mtype
|
2016-04-10 11:44:20 +02:00
|
|
|
h->mtype = bitstream_read_vlc(&s->bc, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2);
|
2013-08-14 17:57:21 +03:00
|
|
|
if (h->mtype < 0 || h->mtype >= FF_ARRAY_ELEMS(ff_h261_mtype_map)) {
|
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index %d\n",
|
|
|
|
h->mtype);
|
|
|
|
return SLICE_ERROR;
|
|
|
|
}
|
2013-04-04 15:56:01 +03:00
|
|
|
h->mtype = ff_h261_mtype_map[h->mtype];
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
// Read mquant
|
2013-04-04 15:31:58 +03:00
|
|
|
if (IS_QUANT(h->mtype))
|
2016-04-10 11:44:20 +02:00
|
|
|
ff_set_qscale(s, bitstream_read(&s->bc, 5));
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
s->mb_intra = IS_INTRA4x4(h->mtype);
|
|
|
|
|
|
|
|
// Read mv
|
2013-04-04 15:31:58 +03:00
|
|
|
if (IS_16X16(h->mtype)) {
|
|
|
|
/* Motion vector data is included for all MC macroblocks. MVD is
|
|
|
|
* obtained from the macroblock vector by subtracting the vector
|
|
|
|
* of the preceding macroblock. For this calculation the vector
|
|
|
|
* of the preceding macroblock is regarded as zero in the
|
|
|
|
* following three situations:
|
|
|
|
* 1) evaluating MVD for macroblocks 1, 12 and 23;
|
|
|
|
* 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
|
|
|
|
* 3) MTYPE of the previous macroblock was not MC. */
|
|
|
|
if ((h->current_mba == 1) || (h->current_mba == 12) ||
|
|
|
|
(h->current_mba == 23) || (h->mba_diff != 1)) {
|
2007-05-21 15:51:29 +03:00
|
|
|
h->current_mv_x = 0;
|
|
|
|
h->current_mv_y = 0;
|
|
|
|
}
|
|
|
|
|
2016-04-10 11:44:20 +02:00
|
|
|
h->current_mv_x = decode_mv_component(&s->bc, h->current_mv_x);
|
|
|
|
h->current_mv_y = decode_mv_component(&s->bc, h->current_mv_y);
|
2013-04-04 15:31:58 +03:00
|
|
|
} else {
|
2007-05-21 15:51:29 +03:00
|
|
|
h->current_mv_x = 0;
|
|
|
|
h->current_mv_y = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Read cbp
|
2013-04-04 15:31:58 +03:00
|
|
|
if (HAS_CBP(h->mtype))
|
2016-04-10 11:44:20 +02:00
|
|
|
cbp = bitstream_read_vlc(&s->bc, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
if (s->mb_intra) {
|
2012-11-21 23:34:46 +03:00
|
|
|
s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
|
2007-05-21 15:51:29 +03:00
|
|
|
goto intra;
|
|
|
|
}
|
|
|
|
|
|
|
|
//set motion vectors
|
2013-04-04 15:31:58 +03:00
|
|
|
s->mv_dir = MV_DIR_FORWARD;
|
|
|
|
s->mv_type = MV_TYPE_16X16;
|
2012-11-21 23:34:46 +03:00
|
|
|
s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
|
2013-04-04 15:31:58 +03:00
|
|
|
s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation
|
|
|
|
s->mv[0][0][1] = h->current_mv_y * 2;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
intra:
|
|
|
|
/* decode each block */
|
2013-04-04 15:31:58 +03:00
|
|
|
if (s->mb_intra || HAS_CBP(h->mtype)) {
|
2014-01-14 12:33:47 +03:00
|
|
|
s->bdsp.clear_blocks(s->block[0]);
|
2007-05-21 15:51:29 +03:00
|
|
|
for (i = 0; i < 6; i++) {
|
2013-04-04 15:31:58 +03:00
|
|
|
if (h261_decode_block(h, s->block[i], i, cbp & 32) < 0)
|
2007-05-21 15:51:29 +03:00
|
|
|
return SLICE_ERROR;
|
2013-04-04 15:31:58 +03:00
|
|
|
cbp += cbp;
|
2007-05-21 15:51:29 +03:00
|
|
|
}
|
2013-04-04 15:31:58 +03:00
|
|
|
} else {
|
2007-05-21 15:51:29 +03:00
|
|
|
for (i = 0; i < 6; i++)
|
2013-04-04 15:31:58 +03:00
|
|
|
s->block_last_index[i] = -1;
|
2007-05-21 15:51:29 +03:00
|
|
|
}
|
|
|
|
|
2014-08-10 18:25:12 +03:00
|
|
|
ff_mpv_decode_mb(s, s->block);
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
return SLICE_OK;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
2011-12-07 15:03:53 +03:00
|
|
|
* Decode the H.261 picture header.
|
2007-05-21 15:51:29 +03:00
|
|
|
* @return <0 if no startcode found
|
|
|
|
*/
|
2013-04-04 15:31:58 +03:00
|
|
|
static int h261_decode_picture_header(H261Context *h)
|
|
|
|
{
|
|
|
|
MpegEncContext *const s = &h->s;
|
2007-05-21 15:51:29 +03:00
|
|
|
int format, i;
|
2013-04-04 15:31:58 +03:00
|
|
|
uint32_t startcode = 0;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2016-04-10 11:44:20 +02:00
|
|
|
for (i = bitstream_bits_left(&s->bc); i > 24; i -= 1) {
|
|
|
|
startcode = ((startcode << 1) | bitstream_read(&s->bc, 1)) & 0x000FFFFF;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
if (startcode == 0x10)
|
2007-05-21 15:51:29 +03:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
if (startcode != 0x10) {
|
2007-05-21 15:51:29 +03:00
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* temporal reference */
|
2016-04-10 11:44:20 +02:00
|
|
|
i = bitstream_read(&s->bc, 5); /* picture timestamp */
|
2013-04-04 15:31:58 +03:00
|
|
|
if (i < (s->picture_number & 31))
|
2007-05-21 15:51:29 +03:00
|
|
|
i += 32;
|
2013-04-04 15:31:58 +03:00
|
|
|
s->picture_number = (s->picture_number & ~31) + i;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2014-04-04 13:47:44 +03:00
|
|
|
s->avctx->framerate = (AVRational) { 30000, 1001 };
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
/* PTYPE starts here */
|
2016-04-10 11:44:20 +02:00
|
|
|
bitstream_skip(&s->bc, 1); /* split screen off */
|
|
|
|
bitstream_skip(&s->bc, 1); /* camera off */
|
|
|
|
bitstream_skip(&s->bc, 1); /* freeze picture release off */
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2016-04-10 11:44:20 +02:00
|
|
|
format = bitstream_read_bit(&s->bc);
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
// only 2 formats possible
|
|
|
|
if (format == 0) { // QCIF
|
|
|
|
s->width = 176;
|
|
|
|
s->height = 144;
|
|
|
|
s->mb_width = 11;
|
2007-05-21 15:51:29 +03:00
|
|
|
s->mb_height = 9;
|
2013-04-04 15:31:58 +03:00
|
|
|
} else { // CIF
|
|
|
|
s->width = 352;
|
|
|
|
s->height = 288;
|
|
|
|
s->mb_width = 22;
|
2007-05-21 15:51:29 +03:00
|
|
|
s->mb_height = 18;
|
|
|
|
}
|
|
|
|
|
|
|
|
s->mb_num = s->mb_width * s->mb_height;
|
|
|
|
|
2016-04-10 11:44:20 +02:00
|
|
|
bitstream_skip(&s->bc, 1); /* still image mode off */
|
|
|
|
bitstream_skip(&s->bc, 1); /* Reserved */
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
/* PEI */
|
2016-04-10 11:44:20 +02:00
|
|
|
while (bitstream_read_bit(&s->bc) != 0)
|
|
|
|
bitstream_skip(&s->bc, 8);
|
2007-05-21 15:51:29 +03:00
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
/* H.261 has no I-frames, but if we pass AV_PICTURE_TYPE_I for the first
|
|
|
|
* frame, the codec crashes if it does not contain all I-blocks
|
|
|
|
* (e.g. when a packet is lost). */
|
2011-04-29 19:53:57 +03:00
|
|
|
s->pict_type = AV_PICTURE_TYPE_P;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
h->gob_number = 0;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
static int h261_decode_gob(H261Context *h)
|
|
|
|
{
|
|
|
|
MpegEncContext *const s = &h->s;
|
2007-05-21 15:51:29 +03:00
|
|
|
|
|
|
|
ff_set_qscale(s, s->qscale);
|
|
|
|
|
|
|
|
/* decode mb's */
|
2013-04-04 15:31:58 +03:00
|
|
|
while (h->current_mba <= MBA_STUFFING) {
|
2007-05-21 15:51:29 +03:00
|
|
|
int ret;
|
|
|
|
/* DCT & quantize */
|
2013-04-04 15:31:58 +03:00
|
|
|
ret = h261_decode_mb(h);
|
|
|
|
if (ret < 0) {
|
|
|
|
if (ret == SLICE_END) {
|
2007-05-21 15:51:29 +03:00
|
|
|
h261_decode_mb_skipped(h, h->current_mba, 33);
|
|
|
|
return 0;
|
|
|
|
}
|
2013-04-04 15:31:58 +03:00
|
|
|
av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n",
|
|
|
|
s->mb_x + s->mb_y * s->mb_stride);
|
2007-05-21 15:51:29 +03:00
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2013-04-04 15:31:58 +03:00
|
|
|
h261_decode_mb_skipped(h,
|
|
|
|
h->current_mba - h->mba_diff,
|
|
|
|
h->current_mba - 1);
|
2007-05-21 15:51:29 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
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* returns the number of bytes consumed for building the current frame
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*/
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2013-04-04 15:31:58 +03:00
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static int get_consumed_bytes(MpegEncContext *s, int buf_size)
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{
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2016-04-10 11:44:20 +02:00
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int pos = bitstream_tell(&s->bc) >> 3;
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2013-04-04 15:31:58 +03:00
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if (pos == 0)
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pos = 1; // avoid infinite loops (i doubt that is needed but ...)
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if (pos + 10 > buf_size)
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pos = buf_size; // oops ;)
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2007-05-21 15:51:29 +03:00
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return pos;
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}
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2013-04-04 15:31:58 +03:00
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static int h261_decode_frame(AVCodecContext *avctx, void *data,
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int *got_frame, AVPacket *avpkt)
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2007-05-21 15:51:29 +03:00
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{
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2009-04-07 18:59:50 +03:00
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const uint8_t *buf = avpkt->data;
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2013-04-04 15:31:58 +03:00
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int buf_size = avpkt->size;
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H261Context *h = avctx->priv_data;
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MpegEncContext *s = &h->s;
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2007-05-21 15:51:29 +03:00
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int ret;
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AVFrame *pict = data;
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2015-03-16 10:57:36 +02:00
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ff_dlog(avctx, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
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ff_dlog(avctx, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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h->gob_start_code_skipped = 0;
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2007-05-21 15:51:29 +03:00
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retry:
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2016-04-10 11:44:20 +02:00
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bitstream_init8(&s->bc, buf, buf_size);
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2007-05-21 15:51:29 +03:00
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2014-08-08 18:55:48 +03:00
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if (!s->context_initialized)
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2016-04-27 19:45:23 +02:00
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// we need the IDCT permutation for reading a custom matrix
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2014-08-08 18:11:20 +03:00
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ff_mpv_idct_init(s);
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2007-05-21 15:51:29 +03:00
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ret = h261_decode_picture_header(h);
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/* skip if the header was thrashed */
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2013-04-04 15:31:58 +03:00
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if (ret < 0) {
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2007-05-21 15:51:29 +03:00
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av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
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return -1;
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}
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2013-04-04 15:31:58 +03:00
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if (s->width != avctx->coded_width || s->height != avctx->coded_height) {
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ParseContext pc = s->parse_context; // FIXME move this demuxing hack to libavformat
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s->parse_context.buffer = 0;
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2014-08-10 18:25:12 +03:00
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ff_mpv_common_end(s);
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2013-04-04 15:31:58 +03:00
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s->parse_context = pc;
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2007-05-21 15:51:29 +03:00
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}
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2014-08-08 18:55:48 +03:00
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2014-08-15 03:50:41 +03:00
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if (!s->context_initialized) {
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2014-08-10 18:25:12 +03:00
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if ((ret = ff_mpv_common_init(s)) < 0)
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2014-08-08 18:55:48 +03:00
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return ret;
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2013-10-27 12:02:26 +03:00
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ret = ff_set_dimensions(avctx, s->width, s->height);
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if (ret < 0)
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return ret;
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2007-05-21 15:51:29 +03:00
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goto retry;
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}
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2011-04-02 12:56:21 +03:00
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// for skipping the frame
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2014-03-31 20:46:29 +03:00
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s->current_picture.f->pict_type = s->pict_type;
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s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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if ((avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type == AV_PICTURE_TYPE_B) ||
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(avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) ||
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avctx->skip_frame >= AVDISCARD_ALL)
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2007-05-21 15:51:29 +03:00
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return get_consumed_bytes(s, buf_size);
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2014-08-10 18:25:12 +03:00
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if (ff_mpv_frame_start(s, avctx) < 0)
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2007-05-21 15:51:29 +03:00
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return -1;
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2013-02-02 22:42:07 +03:00
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ff_mpeg_er_frame_start(s);
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2007-05-21 15:51:29 +03:00
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/* decode each macroblock */
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2013-04-04 15:31:58 +03:00
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s->mb_x = 0;
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s->mb_y = 0;
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2007-05-21 15:51:29 +03:00
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2013-04-04 15:31:58 +03:00
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while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) {
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2013-04-20 22:51:11 +03:00
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if (h261_resync(h) < 0)
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2007-05-21 15:51:29 +03:00
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break;
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h261_decode_gob(h);
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}
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2014-08-10 18:25:12 +03:00
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ff_mpv_frame_end(s);
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2007-05-21 15:51:29 +03:00
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2014-03-31 20:46:29 +03:00
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assert(s->current_picture.f->pict_type == s->current_picture_ptr->f->pict_type);
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assert(s->current_picture.f->pict_type == s->pict_type);
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2012-02-28 00:08:41 +03:00
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2014-03-31 20:46:29 +03:00
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if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
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2012-11-21 23:34:46 +03:00
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return ret;
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ff_print_debug_info(s, s->current_picture_ptr);
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2007-05-21 15:51:29 +03:00
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2012-11-13 21:35:22 +03:00
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*got_frame = 1;
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2007-05-21 15:51:29 +03:00
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return get_consumed_bytes(s, buf_size);
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}
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2008-03-21 05:11:20 +02:00
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static av_cold int h261_decode_end(AVCodecContext *avctx)
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2007-05-21 15:51:29 +03:00
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{
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2013-04-04 15:31:58 +03:00
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H261Context *h = avctx->priv_data;
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2007-05-21 15:51:29 +03:00
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MpegEncContext *s = &h->s;
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2014-08-10 18:25:12 +03:00
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ff_mpv_common_end(s);
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2007-05-21 15:51:29 +03:00
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return 0;
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}
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2011-01-25 23:40:11 +02:00
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AVCodec ff_h261_decoder = {
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2011-07-17 13:54:31 +03:00
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.name = "h261",
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2013-10-03 23:57:53 +03:00
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.long_name = NULL_IF_CONFIG_SMALL("H.261"),
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2011-07-17 13:54:31 +03:00
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.type = AVMEDIA_TYPE_VIDEO,
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2012-08-05 12:11:04 +03:00
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.id = AV_CODEC_ID_H261,
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2011-07-17 13:54:31 +03:00
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.priv_data_size = sizeof(H261Context),
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.init = h261_decode_init,
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.close = h261_decode_end,
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.decode = h261_decode_frame,
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2015-07-07 02:41:27 +02:00
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.capabilities = AV_CODEC_CAP_DR1,
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2007-05-21 15:51:29 +03:00
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};
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