2 * Microsoft RTP/ASF support.
3 * Copyright (c) 2008 Ronald S. Bultje
5 * This file is part of FFmpeg.
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.
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.
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
24 * @brief Microsoft RTP/ASF support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
28 #include "libavutil/base64.h"
29 #include "libavutil/avstring.h"
30 #include "libavutil/intreadwrite.h"
32 #include "rtpdec_formats.h"
35 #include "avio_internal.h"
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).
45 static int rtp_asf_fix_header(uint8_t *buf, int len)
47 uint8_t *p = buf, *end = buf + len;
49 if (len < sizeof(ff_asf_guid) * 2 + 22 ||
50 memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
53 p += sizeof(ff_asf_guid) + 14;
55 uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
56 if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
57 if (chunksize > end - p)
63 /* skip most of the file header, to min_pktsize */
64 p += 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
65 if (p + 8 <= end && AV_RL32(p) == AV_RL32(p + 4)) {
66 /* and set that to zero */
71 } while (end - p >= sizeof(ff_asf_guid) + 8);
77 * The following code is basically a buffered AVIOContext,
78 * with the added benefit of returning -EAGAIN (instead of 0)
79 * on packet boundaries, such that the ASF demuxer can return
80 * safely and resume business at the next packet.
82 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
84 return AVERROR(EAGAIN);
87 static void init_packetizer(AVIOContext *pb, uint8_t *buf, int len)
89 ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);
91 /* this "fills" the buffer with its current content */
93 pb->buf_end = buf + len;
96 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
99 if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
101 RTSPState *rt = s->priv_data;
102 AVDictionary *opts = NULL;
103 int len = strlen(p) * 6 / 8;
104 char *buf = av_mallocz(len);
105 av_base64_decode(buf, p, len);
107 if (rtp_asf_fix_header(buf, len) < 0)
108 av_log(s, AV_LOG_ERROR,
109 "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
110 init_packetizer(&pb, buf, len);
112 avformat_close_input(&rt->asf_ctx);
114 if (!(rt->asf_ctx = avformat_alloc_context()))
115 return AVERROR(ENOMEM);
116 rt->asf_ctx->pb = &pb;
117 av_dict_set(&opts, "no_resync_search", "1", 0);
118 ret = avformat_open_input(&rt->asf_ctx, "", &ff_asf_demuxer, &opts);
122 av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
123 rt->asf_pb_pos = avio_tell(&pb);
125 rt->asf_ctx->pb = NULL;
130 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
131 PayloadContext *asf, const char *line)
133 if (stream_index < 0)
135 if (av_strstart(line, "stream:", &line)) {
136 RTSPState *rt = s->priv_data;
138 s->streams[stream_index]->id = strtol(line, NULL, 10);
143 for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
144 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
145 *s->streams[stream_index]->codec =
146 *rt->asf_ctx->streams[i]->codec;
147 rt->asf_ctx->streams[i]->codec->extradata_size = 0;
148 rt->asf_ctx->streams[i]->codec->extradata = NULL;
149 avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
158 struct PayloadContext {
159 AVIOContext *pktbuf, pb;
164 * @return 0 when a packet was written into /p pkt, and no more data is left;
165 * 1 when a packet was written into /p pkt, and more packets might be left;
166 * <0 when not enough data was provided to return a full packet, or on error.
168 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
169 AVStream *st, AVPacket *pkt,
171 const uint8_t *buf, int len, uint16_t seq,
174 AVIOContext *pb = &asf->pb;
175 int res, mflags, len_off;
176 RTSPState *rt = s->priv_data;
182 int off, out_len = 0;
189 ffio_init_context(pb, buf, len, 0, NULL, NULL, NULL, NULL);
191 while (avio_tell(pb) + 4 < len) {
192 int start_off = avio_tell(pb);
194 mflags = avio_r8(pb);
196 flags |= RTP_FLAG_KEY;
197 len_off = avio_rb24(pb);
198 if (mflags & 0x20) /**< relative timestamp */
200 if (mflags & 0x10) /**< has duration */
202 if (mflags & 0x8) /**< has location ID */
206 if (!(mflags & 0x40)) {
208 * If 0x40 is not set, the len_off field specifies an offset
209 * of this packet's payload data in the complete (reassembled)
210 * ASF packet. This is used to spread one ASF packet over
211 * multiple RTP packets.
213 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
215 avio_close_dyn_buf(asf->pktbuf, &p);
219 if (!len_off && !asf->pktbuf &&
220 (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
225 avio_write(asf->pktbuf, buf + off, len - off);
226 avio_skip(pb, len - off);
227 if (!(flags & RTP_FLAG_MARKER))
229 out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
233 * If 0x40 is set, the len_off field specifies the length of
234 * the next ASF packet that can be read from this payload
235 * data alone. This is commonly the same as the payload size,
236 * but could be less in case of packet splitting (i.e.
237 * multiple ASF packets in one RTP packet).
240 int cur_len = start_off + len_off - off;
241 int prev_len = out_len;
244 if (FFMIN(cur_len, len - off) < 0)
246 newmem = av_realloc(asf->buf, out_len);
250 memcpy(asf->buf + prev_len, buf + off,
251 FFMIN(cur_len, len - off));
252 avio_skip(pb, cur_len);
256 init_packetizer(pb, asf->buf, out_len);
257 pb->pos += rt->asf_pb_pos;
259 rt->asf_ctx->pb = pb;
265 res = ff_read_packet(rt->asf_ctx, pkt);
266 rt->asf_pb_pos = avio_tell(pb);
269 for (i = 0; i < s->nb_streams; i++) {
270 if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
271 pkt->stream_index = i;
272 return 1; // FIXME: return 0 if last packet
278 return res == 1 ? -1 : res;
281 static PayloadContext *asfrtp_new_context(void)
283 return av_mallocz(sizeof(PayloadContext));
286 static void asfrtp_free_context(PayloadContext *asf)
290 avio_close_dyn_buf(asf->pktbuf, &p);
298 #define RTP_ASF_HANDLER(n, s, t) \
299 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
302 .codec_id = AV_CODEC_ID_NONE, \
303 .parse_sdp_a_line = asfrtp_parse_sdp_line, \
304 .alloc = asfrtp_new_context, \
305 .free = asfrtp_free_context, \
306 .parse_packet = asfrtp_parse_packet, \
309 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO);
310 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO);