1/*
2 * H.263i decoder
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "mpegvideo.h"
22#include "h263.h"
23
24/* don't understand why they choose a different header ! */
25int ff_intel_h263_decode_picture_header(MpegEncContext *s)
26{
27    int format;
28
29    /* picture header */
30    if (get_bits_long(&s->gb, 22) != 0x20) {
31        av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
32        return -1;
33    }
34    s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
35
36    if (get_bits1(&s->gb) != 1) {
37        av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
38        return -1;      /* marker */
39    }
40    if (get_bits1(&s->gb) != 0) {
41        av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
42        return -1;      /* h263 id */
43    }
44    skip_bits1(&s->gb);         /* split screen off */
45    skip_bits1(&s->gb);         /* camera  off */
46    skip_bits1(&s->gb);         /* freeze picture release off */
47
48    format = get_bits(&s->gb, 3);
49    if (format == 0 || format == 6) {
50        av_log(s->avctx, AV_LOG_ERROR, "Intel H263 free format not supported\n");
51        return -1;
52    }
53    s->h263_plus = 0;
54
55    s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
56
57    s->unrestricted_mv = get_bits1(&s->gb);
58    s->h263_long_vectors = s->unrestricted_mv;
59
60    if (get_bits1(&s->gb) != 0) {
61        av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n");
62        return -1;      /* SAC: off */
63    }
64    s->obmc= get_bits1(&s->gb);
65    s->pb_frame = get_bits1(&s->gb);
66
67    if (format < 6) {
68        s->width = ff_h263_format[format][0];
69        s->height = ff_h263_format[format][1];
70        s->avctx->sample_aspect_ratio.num = 12;
71        s->avctx->sample_aspect_ratio.den = 11;
72    } else {
73        format = get_bits(&s->gb, 3);
74        if(format == 0 || format == 7){
75            av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n");
76            return -1;
77        }
78        if(get_bits(&s->gb, 2))
79            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
80        s->loop_filter = get_bits1(&s->gb);
81        if(get_bits1(&s->gb))
82            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
83        if(get_bits1(&s->gb))
84            s->pb_frame = 2;
85        if(get_bits(&s->gb, 5))
86            av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
87        if(get_bits(&s->gb, 5) != 1)
88            av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
89    }
90    if(format == 6){
91        int ar = get_bits(&s->gb, 4);
92        skip_bits(&s->gb, 9); // display width
93        skip_bits1(&s->gb);
94        skip_bits(&s->gb, 9); // display height
95        if(ar == 15){
96            s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width
97            s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height
98        } else {
99            s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[ar];
100        }
101        if (s->avctx->sample_aspect_ratio.num == 0)
102            av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n");
103    }
104
105    s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
106    skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
107
108    if(s->pb_frame){
109        skip_bits(&s->gb, 3); //temporal reference for B-frame
110        skip_bits(&s->gb, 2); //dbquant
111    }
112
113    /* PEI */
114    while (get_bits1(&s->gb) != 0) {
115        skip_bits(&s->gb, 8);
116    }
117    s->f_code = 1;
118
119    s->y_dc_scale_table=
120    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
121
122    ff_h263_show_pict_info(s);
123
124    return 0;
125}
126
127AVCodec ff_h263i_decoder = {
128    .name           = "h263i",
129    .type           = AVMEDIA_TYPE_VIDEO,
130    .id             = CODEC_ID_H263I,
131    .priv_data_size = sizeof(MpegEncContext),
132    .init           = ff_h263_decode_init,
133    .close          = ff_h263_decode_end,
134    .decode         = ff_h263_decode_frame,
135    .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
136    .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
137    .pix_fmts= ff_pixfmt_list_420,
138};
139
140