FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/rtpdec_asf.c
Date: 2024-06-18 05:56:57
Exec Total Coverage
Lines: 0 146 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 "libavutil/mem.h"
32 #include "rtpdec_formats.h"
33 #include "rtsp.h"
34 #include "asf.h"
35 #include "avio_internal.h"
36 #include "demux.h"
37 #include "internal.h"
38
39 /**
40 * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
41 * contain any padding. Unfortunately, the header min/max_pktsize are not
42 * updated (thus making min_pktsize invalid). Here, we "fix" these faulty
43 * min_pktsize values in the ASF file header.
44 * @return 0 on success, <0 on failure (currently -1).
45 */
46 static int rtp_asf_fix_header(uint8_t *buf, int len)
47 {
48 uint8_t *p = buf, *end = buf + len;
49
50 if (len < sizeof(ff_asf_guid) * 2 + 22 ||
51 memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
52 return -1;
53 }
54 p += sizeof(ff_asf_guid) + 14;
55 do {
56 uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
57 int skip = 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
58 if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
59 if (chunksize > end - p)
60 return -1;
61 p += chunksize;
62 continue;
63 }
64
65 if (end - p < 8 + skip)
66 break;
67 /* skip most of the file header, to min_pktsize */
68 p += skip;
69 if (AV_RL32(p) == AV_RL32(p + 4)) {
70 /* and set that to zero */
71 AV_WL32(p, 0);
72 return 0;
73 }
74 break;
75 } while (end - p >= sizeof(ff_asf_guid) + 8);
76
77 return -1;
78 }
79
80 /**
81 * The following code is basically a buffered AVIOContext,
82 * with the added benefit of returning -EAGAIN (instead of 0)
83 * on packet boundaries, such that the ASF demuxer can return
84 * safely and resume business at the next packet.
85 */
86 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
87 {
88 return AVERROR(EAGAIN);
89 }
90
91 static void init_packetizer(FFIOContext *pb, uint8_t *buf, int len)
92 {
93 ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
94
95 /* this "fills" the buffer with its current content */
96 pb->pub.pos = len;
97 pb->pub.buf_end = buf + len;
98 }
99
100 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
101 {
102 int ret = 0;
103 if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
104 FFIOContext pb;
105 RTSPState *rt = s->priv_data;
106 AVDictionary *opts = NULL;
107 int len = strlen(p) * 6 / 8;
108 char *buf = av_mallocz(len);
109 const AVInputFormat *iformat;
110
111 if (!buf)
112 return AVERROR(ENOMEM);
113 av_base64_decode(buf, p, len);
114
115 if (rtp_asf_fix_header(buf, len) < 0)
116 av_log(s, AV_LOG_ERROR,
117 "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
118 init_packetizer(&pb, buf, len);
119 if (rt->asf_ctx) {
120 avformat_close_input(&rt->asf_ctx);
121 }
122
123 if (!(iformat = av_find_input_format("asf")))
124 return AVERROR_DEMUXER_NOT_FOUND;
125
126 rt->asf_ctx = avformat_alloc_context();
127 if (!rt->asf_ctx) {
128 av_free(buf);
129 return AVERROR(ENOMEM);
130 }
131 rt->asf_ctx->pb = &pb.pub;
132 av_dict_set(&opts, "no_resync_search", "1", 0);
133
134 if ((ret = ff_copy_whiteblacklists(rt->asf_ctx, s)) < 0) {
135 av_dict_free(&opts);
136 return ret;
137 }
138
139 ret = avformat_open_input(&rt->asf_ctx, "", iformat, &opts);
140 av_dict_free(&opts);
141 if (ret < 0) {
142 av_free(pb.pub.buffer);
143 return ret;
144 }
145 av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
146 rt->asf_pb_pos = avio_tell(&pb.pub);
147 av_free(pb.pub.buffer);
148 rt->asf_ctx->pb = NULL;
149 }
150 return ret;
151 }
152
153 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
154 PayloadContext *asf, const char *line)
155 {
156 if (stream_index < 0)
157 return 0;
158 if (av_strstart(line, "stream:", &line)) {
159 RTSPState *rt = s->priv_data;
160
161 s->streams[stream_index]->id = strtol(line, NULL, 10);
162
163 if (rt->asf_ctx) {
164 int i;
165
166 for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
167 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
168 avcodec_parameters_copy(s->streams[stream_index]->codecpar,
169 rt->asf_ctx->streams[i]->codecpar);
170 ffstream(s->streams[stream_index])->need_parsing =
171 ffstream(rt->asf_ctx->streams[i])->need_parsing;
172 avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
173 }
174 }
175 }
176 }
177
178 return 0;
179 }
180
181 struct PayloadContext {
182 FFIOContext pb;
183 AVIOContext *pktbuf;
184 uint8_t *buf;
185 };
186
187 /**
188 * @return 0 when a packet was written into /p pkt, and no more data is left;
189 * 1 when a packet was written into /p pkt, and more packets might be left;
190 * <0 when not enough data was provided to return a full packet, or on error.
191 */
192 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
193 AVStream *st, AVPacket *pkt,
194 uint32_t *timestamp,
195 const uint8_t *buf, int len, uint16_t seq,
196 int flags)
197 {
198 FFIOContext *const pb0 = &asf->pb;
199 AVIOContext *const pb = &pb0->pub;
200 int res, mflags, len_off;
201 RTSPState *rt = s->priv_data;
202
203 if (!rt->asf_ctx)
204 return -1;
205
206 if (len > 0) {
207 int off, out_len = 0;
208
209 if (len < 4)
210 return -1;
211
212 av_freep(&asf->buf);
213
214 ffio_init_read_context(pb0, buf, len);
215
216 while (avio_tell(pb) + 4 < len) {
217 int start_off = avio_tell(pb);
218
219 mflags = avio_r8(pb);
220 len_off = avio_rb24(pb);
221 if (mflags & 0x20) /**< relative timestamp */
222 avio_skip(pb, 4);
223 if (mflags & 0x10) /**< has duration */
224 avio_skip(pb, 4);
225 if (mflags & 0x8) /**< has location ID */
226 avio_skip(pb, 4);
227 off = avio_tell(pb);
228
229 if (!(mflags & 0x40)) {
230 /**
231 * If 0x40 is not set, the len_off field specifies an offset
232 * of this packet's payload data in the complete (reassembled)
233 * ASF packet. This is used to spread one ASF packet over
234 * multiple RTP packets.
235 */
236 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
237 ffio_free_dyn_buf(&asf->pktbuf);
238 }
239 if (!len_off && !asf->pktbuf &&
240 (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
241 return res;
242 if (!asf->pktbuf)
243 return AVERROR(EIO);
244
245 avio_write(asf->pktbuf, buf + off, len - off);
246 avio_skip(pb, len - off);
247 if (!(flags & RTP_FLAG_MARKER))
248 return -1;
249 out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
250 asf->pktbuf = NULL;
251 } else {
252 /**
253 * If 0x40 is set, the len_off field specifies the length of
254 * the next ASF packet that can be read from this payload
255 * data alone. This is commonly the same as the payload size,
256 * but could be less in case of packet splitting (i.e.
257 * multiple ASF packets in one RTP packet).
258 */
259
260 int cur_len = start_off + len_off - off;
261 int prev_len = out_len;
262 out_len += cur_len;
263 if (FFMIN(cur_len, len - off) < 0)
264 return -1;
265 if ((res = av_reallocp(&asf->buf, out_len)) < 0)
266 return res;
267 memcpy(asf->buf + prev_len, buf + off,
268 FFMIN(cur_len, len - off));
269 avio_skip(pb, cur_len);
270 }
271 }
272
273 init_packetizer(pb0, asf->buf, out_len);
274 pb->pos += rt->asf_pb_pos;
275 pb->eof_reached = 0;
276 rt->asf_ctx->pb = pb;
277 }
278
279 for (;;) {
280 int i;
281
282 res = ff_read_packet(rt->asf_ctx, pkt);
283 rt->asf_pb_pos = avio_tell(pb);
284 if (res != 0)
285 break;
286 for (i = 0; i < s->nb_streams; i++) {
287 if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
288 pkt->stream_index = i;
289 return 1; // FIXME: return 0 if last packet
290 }
291 }
292 av_packet_unref(pkt);
293 }
294
295 return res == 1 ? -1 : res;
296 }
297
298 static void asfrtp_close_context(PayloadContext *asf)
299 {
300 ffio_free_dyn_buf(&asf->pktbuf);
301 av_freep(&asf->buf);
302 }
303
304 #define RTP_ASF_HANDLER(n, s, t) \
305 const RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
306 .enc_name = s, \
307 .codec_type = t, \
308 .codec_id = AV_CODEC_ID_NONE, \
309 .priv_data_size = sizeof(PayloadContext), \
310 .parse_sdp_a_line = asfrtp_parse_sdp_line, \
311 .close = asfrtp_close_context, \
312 .parse_packet = asfrtp_parse_packet, \
313 }
314
315 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO);
316 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO);
317