blob: 2c09fda10b7dc96041dfa54fa080b80476e9ac27
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/avassert.h" |
29 | #include "libavutil/base64.h" |
30 | #include "libavutil/avstring.h" |
31 | #include "libavutil/intreadwrite.h" |
32 | #include "rtp.h" |
33 | #include "rtpdec_formats.h" |
34 | #include "rtsp.h" |
35 | #include "asf.h" |
36 | #include "avio_internal.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(AVIOContext *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->pos = len; |
97 | pb->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 | AVIOContext pb = { 0 }; |
105 | RTSPState *rt = s->priv_data; |
106 | AVDictionary *opts = NULL; |
107 | int len = strlen(p) * 6 / 8; |
108 | char *buf = av_mallocz(len); |
109 | 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; |
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(buf); |
143 | return ret; |
144 | } |
145 | av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0); |
146 | rt->asf_pb_pos = avio_tell(&pb); |
147 | av_free(buf); |
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 | s->streams[stream_index]->need_parsing = |
171 | 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 | AVIOContext *pktbuf, pb; |
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 | AVIOContext *pb = &asf->pb; |
198 | int res, mflags, len_off; |
199 | RTSPState *rt = s->priv_data; |
200 | |
201 | if (!rt->asf_ctx) |
202 | return -1; |
203 | |
204 | if (len > 0) { |
205 | int off, out_len = 0; |
206 | |
207 | if (len < 4) |
208 | return -1; |
209 | |
210 | av_freep(&asf->buf); |
211 | |
212 | ffio_init_context(pb, (uint8_t *)buf, len, 0, NULL, NULL, NULL, NULL); |
213 | |
214 | while (avio_tell(pb) + 4 < len) { |
215 | int start_off = avio_tell(pb); |
216 | |
217 | mflags = avio_r8(pb); |
218 | len_off = avio_rb24(pb); |
219 | if (mflags & 0x20) /**< relative timestamp */ |
220 | avio_skip(pb, 4); |
221 | if (mflags & 0x10) /**< has duration */ |
222 | avio_skip(pb, 4); |
223 | if (mflags & 0x8) /**< has location ID */ |
224 | avio_skip(pb, 4); |
225 | off = avio_tell(pb); |
226 | |
227 | if (!(mflags & 0x40)) { |
228 | /** |
229 | * If 0x40 is not set, the len_off field specifies an offset |
230 | * of this packet's payload data in the complete (reassembled) |
231 | * ASF packet. This is used to spread one ASF packet over |
232 | * multiple RTP packets. |
233 | */ |
234 | if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) { |
235 | ffio_free_dyn_buf(&asf->pktbuf); |
236 | } |
237 | if (!len_off && !asf->pktbuf && |
238 | (res = avio_open_dyn_buf(&asf->pktbuf)) < 0) |
239 | return res; |
240 | if (!asf->pktbuf) |
241 | return AVERROR(EIO); |
242 | |
243 | avio_write(asf->pktbuf, buf + off, len - off); |
244 | avio_skip(pb, len - off); |
245 | if (!(flags & RTP_FLAG_MARKER)) |
246 | return -1; |
247 | out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf); |
248 | asf->pktbuf = NULL; |
249 | } else { |
250 | /** |
251 | * If 0x40 is set, the len_off field specifies the length of |
252 | * the next ASF packet that can be read from this payload |
253 | * data alone. This is commonly the same as the payload size, |
254 | * but could be less in case of packet splitting (i.e. |
255 | * multiple ASF packets in one RTP packet). |
256 | */ |
257 | |
258 | int cur_len = start_off + len_off - off; |
259 | int prev_len = out_len; |
260 | out_len += cur_len; |
261 | if (FFMIN(cur_len, len - off) < 0) |
262 | return -1; |
263 | if ((res = av_reallocp(&asf->buf, out_len)) < 0) |
264 | return res; |
265 | memcpy(asf->buf + prev_len, buf + off, |
266 | FFMIN(cur_len, len - off)); |
267 | avio_skip(pb, cur_len); |
268 | } |
269 | } |
270 | |
271 | init_packetizer(pb, asf->buf, out_len); |
272 | pb->pos += rt->asf_pb_pos; |
273 | pb->eof_reached = 0; |
274 | rt->asf_ctx->pb = pb; |
275 | } |
276 | |
277 | for (;;) { |
278 | int i; |
279 | |
280 | res = ff_read_packet(rt->asf_ctx, pkt); |
281 | rt->asf_pb_pos = avio_tell(pb); |
282 | if (res != 0) |
283 | break; |
284 | for (i = 0; i < s->nb_streams; i++) { |
285 | if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) { |
286 | pkt->stream_index = i; |
287 | return 1; // FIXME: return 0 if last packet |
288 | } |
289 | } |
290 | av_packet_unref(pkt); |
291 | } |
292 | |
293 | return res == 1 ? -1 : res; |
294 | } |
295 | |
296 | static void asfrtp_close_context(PayloadContext *asf) |
297 | { |
298 | ffio_free_dyn_buf(&asf->pktbuf); |
299 | av_freep(&asf->buf); |
300 | } |
301 | |
302 | #define RTP_ASF_HANDLER(n, s, t) \ |
303 | RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \ |
304 | .enc_name = s, \ |
305 | .codec_type = t, \ |
306 | .codec_id = AV_CODEC_ID_NONE, \ |
307 | .priv_data_size = sizeof(PayloadContext), \ |
308 | .parse_sdp_a_line = asfrtp_parse_sdp_line, \ |
309 | .close = asfrtp_close_context, \ |
310 | .parse_packet = asfrtp_parse_packet, \ |
311 | } |
312 | |
313 | RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO); |
314 | RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO); |
315 |