7ca15f0243395e71491674b89a97677e0561fabf
[libav.git] / libavformat / rtpdec_asf.c
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 "rtp.h"
32 #include "rtpdec_asf.h"
33 #include "rtsp.h"
34 #include "asf.h"
35
36 /**
37 * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
38 * contain any padding. Unfortunately, the header min/max_pktsize are not
39 * updated (thus making min_pktsize invalid). Here, we "fix" these faulty
40 * min_pktsize values in the ASF file header.
41 * @return 0 on success, <0 on failure (currently -1).
42 */
43 static int rtp_asf_fix_header(uint8_t *buf, int len)
44 {
45 uint8_t *p = buf, *end = buf + len;
46
47 if (len < sizeof(ff_asf_guid) * 2 + 22 ||
48 memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
49 return -1;
50 }
51 p += sizeof(ff_asf_guid) + 14;
52 do {
53 uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
54 if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
55 if (chunksize > end - p)
56 return -1;
57 p += chunksize;
58 continue;
59 }
60
61 /* skip most of the file header, to min_pktsize */
62 p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
63 if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) {
64 /* and set that to zero */
65 AV_WL32(p, 0);
66 return 0;
67 }
68 break;
69 } while (end - p >= sizeof(ff_asf_guid) + 8);
70
71 return -1;
72 }
73
74 /**
75 * The following code is basically a buffered ByteIOContext,
76 * with the added benefit of returning -EAGAIN (instead of 0)
77 * on packet boundaries, such that the ASF demuxer can return
78 * safely and resume business at the next packet.
79 */
80 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
81 {
82 return AVERROR(EAGAIN);
83 }
84
85 static void init_packetizer(ByteIOContext *pb, uint8_t *buf, int len)
86 {
87 init_put_byte(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
88
89 /* this "fills" the buffer with its current content */
90 pb->pos = len;
91 pb->buf_end = buf + len;
92 }
93
94 void ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
95 {
96 if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
97 ByteIOContext pb;
98 RTSPState *rt = s->priv_data;
99 int len = strlen(p) * 6 / 8;
100 char *buf = av_mallocz(len);
101 av_base64_decode(buf, p, len);
102
103 if (rtp_asf_fix_header(buf, len) < 0)
104 av_log(s, AV_LOG_ERROR,
105 "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
106 init_packetizer(&pb, buf, len);
107 if (rt->asf_ctx) {
108 av_close_input_stream(rt->asf_ctx);
109 rt->asf_ctx = NULL;
110 }
111 av_open_input_stream(&rt->asf_ctx, &pb, "", &asf_demuxer, NULL);
112 rt->asf_pb_pos = url_ftell(&pb);
113 av_free(buf);
114 rt->asf_ctx->pb = NULL;
115 }
116 }
117
118 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
119 PayloadContext *asf, const char *line)
120 {
121 if (av_strstart(line, "stream:", &line)) {
122 RTSPState *rt = s->priv_data;
123
124 s->streams[stream_index]->id = strtol(line, NULL, 10);
125
126 if (rt->asf_ctx) {
127 int i;
128
129 for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
130 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
131 *s->streams[stream_index]->codec =
132 *rt->asf_ctx->streams[i]->codec;
133 rt->asf_ctx->streams[i]->codec->extradata_size = 0;
134 rt->asf_ctx->streams[i]->codec->extradata = NULL;
135 av_set_pts_info(s->streams[stream_index], 32, 1, 1000);
136 }
137 }
138 }
139 }
140
141 return 0;
142 }
143
144 struct PayloadContext {
145 ByteIOContext *pktbuf, pb;
146 char *buf;
147 };
148
149 /**
150 * @return 0 when a packet was written into /p pkt, and no more data is left;
151 * 1 when a packet was written into /p pkt, and more packets might be left;
152 * <0 when not enough data was provided to return a full packet, or on error.
153 */
154 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
155 AVStream *st, AVPacket *pkt,
156 uint32_t *timestamp,
157 const uint8_t *buf, int len, int flags)
158 {
159 ByteIOContext *pb = &asf->pb;
160 int res, mflags, len_off;
161 RTSPState *rt = s->priv_data;
162
163 if (!rt->asf_ctx)
164 return -1;
165
166 if (len > 0) {
167 int off, out_len;
168
169 if (len < 4)
170 return -1;
171
172 init_put_byte(pb, buf, len, 0, NULL, NULL, NULL, NULL);
173 mflags = get_byte(pb);
174 if (mflags & 0x80)
175 flags |= RTP_FLAG_KEY;
176 len_off = get_be24(pb);
177 if (mflags & 0x20) /**< relative timestamp */
178 url_fskip(pb, 4);
179 if (mflags & 0x10) /**< has duration */
180 url_fskip(pb, 4);
181 if (mflags & 0x8) /**< has location ID */
182 url_fskip(pb, 4);
183 off = url_ftell(pb);
184
185 av_freep(&asf->buf);
186 if (!(mflags & 0x40)) {
187 /**
188 * If 0x40 is not set, the len_off field specifies an offset of this
189 * packet's payload data in the complete (reassembled) ASF packet.
190 * This is used to spread one ASF packet over multiple RTP packets.
191 */
192 if (asf->pktbuf && len_off != url_ftell(asf->pktbuf)) {
193 uint8_t *p;
194 url_close_dyn_buf(asf->pktbuf, &p);
195 asf->pktbuf = NULL;
196 av_free(p);
197 }
198 if (!len_off && !asf->pktbuf &&
199 (res = url_open_dyn_buf(&asf->pktbuf)) < 0)
200 return res;
201 if (!asf->pktbuf)
202 return AVERROR(EIO);
203
204 put_buffer(asf->pktbuf, buf + off, len - off);
205 if (!(flags & RTP_FLAG_MARKER))
206 return -1;
207 out_len = url_close_dyn_buf(asf->pktbuf, &asf->buf);
208 asf->pktbuf = NULL;
209 } else {
210 /**
211 * If 0x40 is set, the len_off field specifies the length of the
212 * next ASF packet that can be read from this payload data alone.
213 * This is commonly the same as the payload size, but could be
214 * less in case of packet splitting (i.e. multiple ASF packets in
215 * one RTP packet).
216 */
217 if (len_off != len) {
218 av_log_missing_feature(s,
219 "RTSP-MS packet splitting", 1);
220 return -1;
221 }
222 asf->buf = av_malloc(len - off);
223 out_len = len - off;
224 memcpy(asf->buf, buf + off, len - off);
225 }
226
227 init_packetizer(pb, asf->buf, out_len);
228 pb->pos += rt->asf_pb_pos;
229 pb->eof_reached = 0;
230 rt->asf_ctx->pb = pb;
231 }
232
233 for (;;) {
234 int i;
235
236 res = av_read_packet(rt->asf_ctx, pkt);
237 rt->asf_pb_pos = url_ftell(pb);
238 if (res != 0)
239 break;
240 for (i = 0; i < s->nb_streams; i++) {
241 if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
242 pkt->stream_index = i;
243 return 1; // FIXME: return 0 if last packet
244 }
245 }
246 av_free_packet(pkt);
247 }
248
249 return res == 1 ? -1 : res;
250 }
251
252 static PayloadContext *asfrtp_new_context(void)
253 {
254 return av_mallocz(sizeof(PayloadContext));
255 }
256
257 static void asfrtp_free_context(PayloadContext *asf)
258 {
259 if (asf->pktbuf) {
260 uint8_t *p = NULL;
261 url_close_dyn_buf(asf->pktbuf, &p);
262 asf->pktbuf = NULL;
263 av_free(p);
264 }
265 av_freep(&asf->buf);
266 av_free(asf);
267 }
268
269 #define RTP_ASF_HANDLER(n, s, t) \
270 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
271 .enc_name = s, \
272 .codec_type = t, \
273 .codec_id = CODEC_ID_NONE, \
274 .parse_sdp_a_line = asfrtp_parse_sdp_line, \
275 .open = asfrtp_new_context, \
276 .close = asfrtp_free_context, \
277 .parse_packet = asfrtp_parse_packet, \
278 };
279
280 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO);
281 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO);