FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/rtpdec_asf.c
Date: 2022-12-05 03:11:11
Exec Total Coverage
Lines: 0 144 0.0%
Functions: 0 7 0.0%
Branches: 0 82 0.0%

Line Branch Exec Source
1 /*
2 * Microsoft RTP/ASF support.
3 * Copyright (c) 2008 Ronald S. Bultje
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * @brief Microsoft RTP/ASF support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26 */
27
28 #include "libavutil/base64.h"
29 #include "libavutil/avstring.h"
30 #include "libavutil/intreadwrite.h"
31 #include "rtpdec_formats.h"
32 #include "rtsp.h"
33 #include "asf.h"
34 #include "avio_internal.h"
35 #include "demux.h"
36 #include "internal.h"
37
38 /**
39 * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
40 * contain any padding. Unfortunately, the header min/max_pktsize are not
41 * updated (thus making min_pktsize invalid). Here, we "fix" these faulty
42 * min_pktsize values in the ASF file header.
43 * @return 0 on success, <0 on failure (currently -1).
44 */
45 static int rtp_asf_fix_header(uint8_t *buf, int len)
46 {
47 uint8_t *p = buf, *end = buf + len;
48
49 if (len < sizeof(ff_asf_guid) * 2 + 22 ||
50 memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
51 return -1;
52 }
53 p += sizeof(ff_asf_guid) + 14;
54 do {
55 uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
56 int skip = 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
57 if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
58 if (chunksize > end - p)
59 return -1;
60 p += chunksize;
61 continue;
62 }
63
64 if (end - p < 8 + skip)
65 break;
66 /* skip most of the file header, to min_pktsize */
67 p += skip;
68 if (AV_RL32(p) == AV_RL32(p + 4)) {
69 /* and set that to zero */
70 AV_WL32(p, 0);
71 return 0;
72 }
73 break;
74 } while (end - p >= sizeof(ff_asf_guid) + 8);
75
76 return -1;
77 }
78
79 /**
80 * The following code is basically a buffered AVIOContext,
81 * with the added benefit of returning -EAGAIN (instead of 0)
82 * on packet boundaries, such that the ASF demuxer can return
83 * safely and resume business at the next packet.
84 */
85 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
86 {
87 return AVERROR(EAGAIN);
88 }
89
90 static void init_packetizer(FFIOContext *pb, uint8_t *buf, int len)
91 {
92 ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
93
94 /* this "fills" the buffer with its current content */
95 pb->pub.pos = len;
96 pb->pub.buf_end = buf + len;
97 }
98
99 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
100 {
101 int ret = 0;
102 if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
103 FFIOContext pb;
104 RTSPState *rt = s->priv_data;
105 AVDictionary *opts = NULL;
106 int len = strlen(p) * 6 / 8;
107 char *buf = av_mallocz(len);
108 const AVInputFormat *iformat;
109
110 if (!buf)
111 return AVERROR(ENOMEM);
112 av_base64_decode(buf, p, len);
113
114 if (rtp_asf_fix_header(buf, len) < 0)
115 av_log(s, AV_LOG_ERROR,
116 "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
117 init_packetizer(&pb, buf, len);
118 if (rt->asf_ctx) {
119 avformat_close_input(&rt->asf_ctx);
120 }
121
122 if (!(iformat = av_find_input_format("asf")))
123 return AVERROR_DEMUXER_NOT_FOUND;
124
125 rt->asf_ctx = avformat_alloc_context();
126 if (!rt->asf_ctx) {
127 av_free(buf);
128 return AVERROR(ENOMEM);
129 }
130 rt->asf_ctx->pb = &pb.pub;
131 av_dict_set(&opts, "no_resync_search", "1", 0);
132
133 if ((ret = ff_copy_whiteblacklists(rt->asf_ctx, s)) < 0) {
134 av_dict_free(&opts);
135 return ret;
136 }
137
138 ret = avformat_open_input(&rt->asf_ctx, "", iformat, &opts);
139 av_dict_free(&opts);
140 if (ret < 0) {
141 av_free(pb.pub.buffer);
142 return ret;
143 }
144 av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
145 rt->asf_pb_pos = avio_tell(&pb.pub);
146 av_free(pb.pub.buffer);
147 rt->asf_ctx->pb = NULL;
148 }
149 return ret;
150 }
151
152 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
153 PayloadContext *asf, const char *line)
154 {
155 if (stream_index < 0)
156 return 0;
157 if (av_strstart(line, "stream:", &line)) {
158 RTSPState *rt = s->priv_data;
159
160 s->streams[stream_index]->id = strtol(line, NULL, 10);
161
162 if (rt->asf_ctx) {
163 int i;
164
165 for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
166 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
167 avcodec_parameters_copy(s->streams[stream_index]->codecpar,
168 rt->asf_ctx->streams[i]->codecpar);
169 ffstream(s->streams[stream_index])->need_parsing =
170 ffstream(rt->asf_ctx->streams[i])->need_parsing;
171 avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
172 }
173 }
174 }
175 }
176
177 return 0;
178 }
179
180 struct PayloadContext {
181 FFIOContext pb;
182 AVIOContext *pktbuf;
183 uint8_t *buf;
184 };
185
186 /**
187 * @return 0 when a packet was written into /p pkt, and no more data is left;
188 * 1 when a packet was written into /p pkt, and more packets might be left;
189 * <0 when not enough data was provided to return a full packet, or on error.
190 */
191 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
192 AVStream *st, AVPacket *pkt,
193 uint32_t *timestamp,
194 const uint8_t *buf, int len, uint16_t seq,
195 int flags)
196 {
197 FFIOContext *const pb0 = &asf->pb;
198 AVIOContext *const pb = &pb0->pub;
199 int res, mflags, len_off;
200 RTSPState *rt = s->priv_data;
201
202 if (!rt->asf_ctx)
203 return -1;
204
205 if (len > 0) {
206 int off, out_len = 0;
207
208 if (len < 4)
209 return -1;
210
211 av_freep(&asf->buf);
212
213 ffio_init_context(pb0, (uint8_t *)buf, len, 0, NULL, NULL, NULL, NULL);
214
215 while (avio_tell(pb) + 4 < len) {
216 int start_off = avio_tell(pb);
217
218 mflags = avio_r8(pb);
219 len_off = avio_rb24(pb);
220 if (mflags & 0x20) /**< relative timestamp */
221 avio_skip(pb, 4);
222 if (mflags & 0x10) /**< has duration */
223 avio_skip(pb, 4);
224 if (mflags & 0x8) /**< has location ID */
225 avio_skip(pb, 4);
226 off = avio_tell(pb);
227
228 if (!(mflags & 0x40)) {
229 /**
230 * If 0x40 is not set, the len_off field specifies an offset
231 * of this packet's payload data in the complete (reassembled)
232 * ASF packet. This is used to spread one ASF packet over
233 * multiple RTP packets.
234 */
235 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
236 ffio_free_dyn_buf(&asf->pktbuf);
237 }
238 if (!len_off && !asf->pktbuf &&
239 (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
240 return res;
241 if (!asf->pktbuf)
242 return AVERROR(EIO);
243
244 avio_write(asf->pktbuf, buf + off, len - off);
245 avio_skip(pb, len - off);
246 if (!(flags & RTP_FLAG_MARKER))
247 return -1;
248 out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
249 asf->pktbuf = NULL;
250 } else {
251 /**
252 * If 0x40 is set, the len_off field specifies the length of
253 * the next ASF packet that can be read from this payload
254 * data alone. This is commonly the same as the payload size,
255 * but could be less in case of packet splitting (i.e.
256 * multiple ASF packets in one RTP packet).
257 */
258
259 int cur_len = start_off + len_off - off;
260 int prev_len = out_len;
261 out_len += cur_len;
262 if (FFMIN(cur_len, len - off) < 0)
263 return -1;
264 if ((res = av_reallocp(&asf->buf, out_len)) < 0)
265 return res;
266 memcpy(asf->buf + prev_len, buf + off,
267 FFMIN(cur_len, len - off));
268 avio_skip(pb, cur_len);
269 }
270 }
271
272 init_packetizer(pb0, asf->buf, out_len);
273 pb->pos += rt->asf_pb_pos;
274 pb->eof_reached = 0;
275 rt->asf_ctx->pb = pb;
276 }
277
278 for (;;) {
279 int i;
280
281 res = ff_read_packet(rt->asf_ctx, pkt);
282 rt->asf_pb_pos = avio_tell(pb);
283 if (res != 0)
284 break;
285 for (i = 0; i < s->nb_streams; i++) {
286 if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
287 pkt->stream_index = i;
288 return 1; // FIXME: return 0 if last packet
289 }
290 }
291 av_packet_unref(pkt);
292 }
293
294 return res == 1 ? -1 : res;
295 }
296
297 static void asfrtp_close_context(PayloadContext *asf)
298 {
299 ffio_free_dyn_buf(&asf->pktbuf);
300 av_freep(&asf->buf);
301 }
302
303 #define RTP_ASF_HANDLER(n, s, t) \
304 const RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
305 .enc_name = s, \
306 .codec_type = t, \
307 .codec_id = AV_CODEC_ID_NONE, \
308 .priv_data_size = sizeof(PayloadContext), \
309 .parse_sdp_a_line = asfrtp_parse_sdp_line, \
310 .close = asfrtp_close_context, \
311 .parse_packet = asfrtp_parse_packet, \
312 }
313
314 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO);
315 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO);
316