FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/rtpdec_h263_rfc2190.c
Date: 2026-09-28 17:50:41
Exec Total Coverage
Lines: 0 92 0.0%
Functions: 0 2 0.0%
Branches: 0 64 0.0%

Line Branch Exec Source
1 /*
2 * RTP H.263 Depacketizer, RFC 2190
3 * Copyright (c) 2012 Martin Storsjo
4 * Based on the GStreamer H.263 Depayloder:
5 * Copyright 2005 Wim Taymans
6 * Copyright 2007 Edward Hervey
7 * Copyright 2007 Nokia Corporation
8 * Copyright 2007 Collabora Ltd, Philippe Kalaf
9 * Copyright 2010 Mark Nauwelaerts
10 *
11 * This file is part of FFmpeg.
12 *
13 * FFmpeg is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Lesser General Public
15 * License as published by the Free Software Foundation; either
16 * version 2.1 of the License, or (at your option) any later version.
17 *
18 * FFmpeg is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * Lesser General Public License for more details.
22 *
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with FFmpeg; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 */
27
28 #include "avformat.h"
29 #include "avio_internal.h"
30 #include "rtpdec_formats.h"
31 #include "libavutil/attributes.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavcodec/get_bits.h"
34
35 struct PayloadContext {
36 AVIOContext *buf;
37 uint8_t endbyte;
38 int endbyte_bits;
39 uint32_t timestamp;
40 int newformat;
41 };
42
43 ✗ static void h263_close_context(PayloadContext *data)
44 {
45 ✗ ffio_free_dyn_buf(&data->buf);
46 ✗ }
47
48 ✗ static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
49 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
50 const uint8_t *buf, int len, uint16_t seq,
51 int flags)
52 {
53 /* Corresponding to header fields in the RFC */
54 int f, p, i, sbit, ebit, src, r;
55 int header_size, ret;
56
57 ✗ if (data->newformat)
58 ✗ return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, len,
59 seq, flags);
60
61 ✗ if (data->buf && data->timestamp != *timestamp) {
62 /* Dropping old buffered, unfinished data */
63 ✗ ffio_free_dyn_buf(&data->buf);
64 ✗ data->endbyte_bits = 0;
65 }
66
67 ✗ if (len < 4) {
68 ✗ av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet: %d\n", len);
69 ✗ return AVERROR_INVALIDDATA;
70 }
71
72 ✗ f = buf[0] & 0x80;
73 ✗ p = buf[0] & 0x40;
74 ✗ if (!f) {
75 /* Mode A */
76 ✗ header_size = 4;
77 ✗ i = buf[1] & 0x10;
78 ✗ r = ((buf[1] & 0x01) << 3) | ((buf[2] & 0xe0) >> 5);
79 ✗ } else if (!p) {
80 /* Mode B */
81 ✗ header_size = 8;
82 ✗ if (len < header_size) {
83 ✗ av_log(ctx, AV_LOG_ERROR,
84 "Too short H.263 RTP packet: %d bytes, %d header bytes\n",
85 len, header_size);
86 ✗ return AVERROR_INVALIDDATA;
87 }
88 ✗ r = buf[3] & 0x03;
89 ✗ i = buf[4] & 0x80;
90 } else {
91 /* Mode C */
92 ✗ header_size = 12;
93 ✗ if (len < header_size) {
94 ✗ av_log(ctx, AV_LOG_ERROR,
95 "Too short H.263 RTP packet: %d bytes, %d header bytes\n",
96 len, header_size);
97 ✗ return AVERROR_INVALIDDATA;
98 }
99 ✗ r = buf[3] & 0x03;
100 ✗ i = buf[4] & 0x80;
101 }
102 ✗ sbit = (buf[0] >> 3) & 0x7;
103 ✗ ebit = buf[0] & 0x7;
104 ✗ src = (buf[1] & 0xe0) >> 5;
105 ✗ if (!(buf[0] & 0xf8)) { /* Reserved bits in RFC 2429/4629 are zero */
106 ✗ if ((src == 0 || src >= 6) && r) {
107 /* Invalid src for this format, and bits that should be zero
108 * according to RFC 2190 aren't zero. */
109 ✗ av_log(ctx, AV_LOG_WARNING,
110 "Interpreting H.263 RTP data as RFC 2429/4629 even though "
111 "signalled with a static payload type.\n");
112 ✗ data->newformat = 1;
113 ✗ return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf,
114 len, seq, flags);
115 }
116 }
117
118 ✗ buf += header_size;
119 ✗ len -= header_size;
120
121 ✗ if (!len) {
122 ✗ av_log(ctx, AV_LOG_ERROR, "H.263 RTP packet without payload\n");
123 ✗ return AVERROR_INVALIDDATA;
124 }
125
126 ✗ if (!data->buf) {
127 /* Check the picture start code, only start buffering a new frame
128 * if this is correct */
129 ✗ if (len > 4 && AV_RB32(buf) >> 10 == 0x20) {
130 ✗ ret = avio_open_dyn_buf(&data->buf);
131 ✗ if (ret < 0)
132 ✗ return ret;
133 ✗ data->timestamp = *timestamp;
134 } else {
135 /* Frame not started yet, skipping */
136 ✗ return AVERROR(EAGAIN);
137 }
138 }
139
140 ✗ if (data->endbyte_bits || sbit) {
141 ✗ if (data->endbyte_bits == sbit) {
142 ✗ data->endbyte |= buf[0] & (0xff >> sbit);
143 ✗ data->endbyte_bits = 0;
144 ✗ buf++;
145 ✗ len--;
146 ✗ avio_w8(data->buf, data->endbyte);
147 } else {
148 /* Start/end skip bits not matching - missed packets? */
149 GetBitContext gb;
150 ✗ ret = init_get_bits(&gb, buf, len*8 - ebit);
151 ✗ if (ret < 0)
152 ✗ return ret;
153 ✗ if (get_bits_left(&gb) < sbit + (data->endbyte_bits ? 8 - data->endbyte_bits : 0))
154 ✗ return AVERROR_INVALIDDATA;
155 ✗ skip_bits(&gb, sbit);
156 ✗ if (data->endbyte_bits) {
157 ✗ data->endbyte |= get_bits(&gb, 8 - data->endbyte_bits);
158 ✗ avio_w8(data->buf, data->endbyte);
159 }
160 ✗ while (get_bits_left(&gb) >= 8)
161 ✗ avio_w8(data->buf, get_bits(&gb, 8));
162 ✗ data->endbyte_bits = get_bits_left(&gb);
163 ✗ if (data->endbyte_bits)
164 ✗ data->endbyte = get_bits(&gb, data->endbyte_bits) <<
165 ✗ (8 - data->endbyte_bits);
166 ✗ ebit = 0;
167 ✗ len = 0;
168 }
169 }
170 ✗ if (ebit) {
171 ✗ if (len > 0)
172 ✗ avio_write(data->buf, buf, len - 1);
173 ✗ data->endbyte_bits = 8 - ebit;
174 ✗ data->endbyte = buf[len - 1] & (0xff << ebit);
175 } else {
176 ✗ avio_write(data->buf, buf, len);
177 }
178
179 ✗ if (!(flags & RTP_FLAG_MARKER))
180 ✗ return AVERROR(EAGAIN);
181
182 ✗ if (data->endbyte_bits)
183 ✗ avio_w8(data->buf, data->endbyte);
184 ✗ data->endbyte_bits = 0;
185
186 ✗ ret = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
187 ✗ if (ret < 0)
188 ✗ return ret;
189 ✗ if (!i)
190 ✗ pkt->flags |= AV_PKT_FLAG_KEY;
191
192 ✗ return 0;
193 }
194
195 const RTPDynamicProtocolHandler ff_h263_rfc2190_dynamic_handler = {
196 .codec_type = AVMEDIA_TYPE_VIDEO,
197 .codec_id = AV_CODEC_ID_H263,
198 .need_parsing = AVSTREAM_PARSE_FULL,
199 .parse_packet = h263_handle_packet,
200 .priv_data_size = sizeof(PayloadContext),
201 .close = h263_close_context,
202 .static_payload_id = 34,
203 };
204