Line data Source code
1 : /*
2 : * H.263i decoder
3 : *
4 : * This file is part of FFmpeg.
5 : *
6 : * FFmpeg 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 : * FFmpeg 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 FFmpeg; if not, write to the Free Software
18 : * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 : */
20 :
21 : #include "mpegutils.h"
22 : #include "mpegvideo.h"
23 : #include "h263.h"
24 : #include "mpegvideodata.h"
25 :
26 : /* don't understand why they choose a different header ! */
27 0 : int ff_intel_h263_decode_picture_header(MpegEncContext *s)
28 : {
29 : int format;
30 :
31 0 : if (get_bits_left(&s->gb) == 64) { /* special dummy frames */
32 0 : return FRAME_SKIPPED;
33 : }
34 :
35 : /* picture header */
36 0 : if (get_bits_long(&s->gb, 22) != 0x20) {
37 0 : av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
38 0 : return -1;
39 : }
40 0 : s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
41 :
42 0 : if (check_marker(s->avctx, &s->gb, "after picture_number") != 1) {
43 0 : return -1; /* marker */
44 : }
45 0 : if (get_bits1(&s->gb) != 0) {
46 0 : av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
47 0 : return -1; /* H.263 id */
48 : }
49 0 : skip_bits1(&s->gb); /* split screen off */
50 0 : skip_bits1(&s->gb); /* camera off */
51 0 : skip_bits1(&s->gb); /* freeze picture release off */
52 :
53 0 : format = get_bits(&s->gb, 3);
54 0 : if (format == 0 || format == 6) {
55 0 : av_log(s->avctx, AV_LOG_ERROR, "Intel H.263 free format not supported\n");
56 0 : return -1;
57 : }
58 0 : s->h263_plus = 0;
59 :
60 0 : s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
61 :
62 0 : s->h263_long_vectors = get_bits1(&s->gb);
63 :
64 0 : if (get_bits1(&s->gb) != 0) {
65 0 : av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n");
66 0 : return -1; /* SAC: off */
67 : }
68 0 : s->obmc= get_bits1(&s->gb);
69 0 : s->unrestricted_mv = s->obmc || s->h263_long_vectors;
70 0 : s->pb_frame = get_bits1(&s->gb);
71 :
72 0 : if (format < 6) {
73 0 : s->width = ff_h263_format[format][0];
74 0 : s->height = ff_h263_format[format][1];
75 0 : s->avctx->sample_aspect_ratio.num = 12;
76 0 : s->avctx->sample_aspect_ratio.den = 11;
77 : } else {
78 0 : format = get_bits(&s->gb, 3);
79 0 : if(format == 0 || format == 7){
80 0 : av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H.263 format\n");
81 0 : return -1;
82 : }
83 0 : if(get_bits(&s->gb, 2))
84 0 : av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
85 0 : s->loop_filter = get_bits1(&s->gb) * !s->avctx->lowres;
86 0 : if(get_bits1(&s->gb))
87 0 : av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
88 0 : if(get_bits1(&s->gb))
89 0 : s->pb_frame = 2;
90 0 : if(get_bits(&s->gb, 5))
91 0 : av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
92 0 : if(get_bits(&s->gb, 5) != 1)
93 0 : av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
94 : }
95 0 : if(format == 6){
96 0 : int ar = get_bits(&s->gb, 4);
97 0 : skip_bits(&s->gb, 9); // display width
98 0 : check_marker(s->avctx, &s->gb, "in dimensions");
99 0 : skip_bits(&s->gb, 9); // display height
100 0 : if(ar == 15){
101 0 : s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width
102 0 : s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height
103 : } else {
104 0 : s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[ar];
105 : }
106 0 : if (s->avctx->sample_aspect_ratio.num == 0)
107 0 : av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n");
108 : }
109 :
110 0 : s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
111 0 : skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
112 :
113 0 : if(s->pb_frame){
114 0 : skip_bits(&s->gb, 3); //temporal reference for B-frame
115 0 : skip_bits(&s->gb, 2); //dbquant
116 : }
117 :
118 : /* PEI */
119 0 : if (skip_1stop_8data_bits(&s->gb) < 0)
120 0 : return AVERROR_INVALIDDATA;
121 0 : s->f_code = 1;
122 :
123 0 : s->y_dc_scale_table=
124 0 : s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
125 :
126 0 : ff_h263_show_pict_info(s);
127 :
128 0 : return 0;
129 : }
130 :
131 : AVCodec ff_h263i_decoder = {
132 : .name = "h263i",
133 : .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
134 : .type = AVMEDIA_TYPE_VIDEO,
135 : .id = AV_CODEC_ID_H263I,
136 : .priv_data_size = sizeof(MpegEncContext),
137 : .init = ff_h263_decode_init,
138 : .close = ff_h263_decode_end,
139 : .decode = ff_h263_decode_frame,
140 : .capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
141 : .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
142 : .pix_fmts = (const enum AVPixelFormat[]) {
143 : AV_PIX_FMT_YUV420P,
144 : AV_PIX_FMT_NONE
145 : },
146 : };
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