FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/intelh263dec.c
Date: 2025-06-01 09:29:47
Exec Total Coverage
Lines: 0 67 0.0%
Functions: 0 1 0.0%
Branches: 0 44 0.0%

Line Branch Exec Source
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 "codec_internal.h"
22 #include "h263.h"
23 #include "mpegvideo.h"
24 #include "mpegvideodec.h"
25 #include "h263data.h"
26 #include "h263dec.h"
27
28 /* don't understand why they choose a different header ! */
29 int ff_intel_h263_decode_picture_header(MpegEncContext *s)
30 {
31 int format;
32
33 if (get_bits_left(&s->gb) == 64) { /* special dummy frames */
34 return FRAME_SKIPPED;
35 }
36
37 /* picture header */
38 if (get_bits(&s->gb, 22) != 0x20) {
39 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
40 return -1;
41 }
42 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
43
44 if (check_marker(s->avctx, &s->gb, "after picture_number") != 1) {
45 return -1; /* marker */
46 }
47 if (get_bits1(&s->gb) != 0) {
48 av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
49 return -1; /* H.263 id */
50 }
51 skip_bits1(&s->gb); /* split screen off */
52 skip_bits1(&s->gb); /* camera off */
53 skip_bits1(&s->gb); /* freeze picture release off */
54
55 format = get_bits(&s->gb, 3);
56 if (format == 0 || format == 6) {
57 av_log(s->avctx, AV_LOG_ERROR, "Intel H.263 free format not supported\n");
58 return -1;
59 }
60
61 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
62
63 s->h263_long_vectors = get_bits1(&s->gb);
64
65 if (get_bits1(&s->gb) != 0) {
66 av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n");
67 return -1; /* SAC: off */
68 }
69 s->obmc= get_bits1(&s->gb);
70 s->pb_frame = get_bits1(&s->gb);
71
72 if (format < 6) {
73 s->width = ff_h263_format[format][0];
74 s->height = ff_h263_format[format][1];
75 s->avctx->sample_aspect_ratio.num = 12;
76 s->avctx->sample_aspect_ratio.den = 11;
77 } else {
78 format = get_bits(&s->gb, 3);
79 if(format == 0 || format == 7){
80 av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H.263 format\n");
81 return -1;
82 }
83 if(get_bits(&s->gb, 2))
84 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
85 s->loop_filter = get_bits1(&s->gb) * !s->avctx->lowres;
86 if(get_bits1(&s->gb))
87 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
88 if(get_bits1(&s->gb))
89 s->pb_frame = 2;
90 if(get_bits(&s->gb, 5))
91 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n");
92 if(get_bits(&s->gb, 5) != 1)
93 av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n");
94 }
95 if(format == 6){
96 int ar = get_bits(&s->gb, 4);
97 skip_bits(&s->gb, 9); // display width
98 check_marker(s->avctx, &s->gb, "in dimensions");
99 skip_bits(&s->gb, 9); // display height
100 if(ar == 15){
101 s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width
102 s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height
103 } else {
104 s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[ar];
105 }
106 if (s->avctx->sample_aspect_ratio.num == 0)
107 av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n");
108 }
109
110 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
111 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
112
113 if(s->pb_frame){
114 skip_bits(&s->gb, 3); //temporal reference for B-frame
115 skip_bits(&s->gb, 2); //dbquant
116 }
117
118 /* PEI */
119 if (skip_1stop_8data_bits(&s->gb) < 0)
120 return AVERROR_INVALIDDATA;
121
122 s->gob_index = H263_GOB_HEIGHT(s->height);
123
124 ff_h263_show_pict_info(s, 0);
125
126 return 0;
127 }
128
129 const FFCodec ff_h263i_decoder = {
130 .p.name = "h263i",
131 CODEC_LONG_NAME("Intel H.263"),
132 .p.type = AVMEDIA_TYPE_VIDEO,
133 .p.id = AV_CODEC_ID_H263I,
134 .priv_data_size = sizeof(MpegEncContext),
135 .init = ff_h263_decode_init,
136 FF_CODEC_DECODE_CB(ff_h263_decode_frame),
137 .close = ff_mpv_decode_close,
138 .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1,
139 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP |
140 FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
141 };
142