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 s
->streams
[stream_index
]->need_parsing
=
148 rt
->asf_ctx
->streams
[i
]->need_parsing
;
149 rt
->asf_ctx
->streams
[i
]->codec
->extradata_size
= 0;
150 rt
->asf_ctx
->streams
[i
]->codec
->extradata
= NULL
;
151 avpriv_set_pts_info(s
->streams
[stream_index
], 32, 1, 1000);
160 struct PayloadContext
{
161 AVIOContext
*pktbuf
, pb
;
166 * @return 0 when a packet was written into /p pkt, and no more data is left;
167 * 1 when a packet was written into /p pkt, and more packets might be left;
168 * <0 when not enough data was provided to return a full packet, or on error.
170 static int asfrtp_parse_packet(AVFormatContext
*s
, PayloadContext
*asf
,
171 AVStream
*st
, AVPacket
*pkt
,
173 const uint8_t *buf
, int len
, uint16_t seq
,
176 AVIOContext
*pb
= &asf
->pb
;
177 int res
, mflags
, len_off
;
178 RTSPState
*rt
= s
->priv_data
;
184 int off
, out_len
= 0;
191 ffio_init_context(pb
, (uint8_t *)buf
, len
, 0, NULL
, NULL
, NULL
, NULL
);
193 while (avio_tell(pb
) + 4 < len
) {
194 int start_off
= avio_tell(pb
);
196 mflags
= avio_r8(pb
);
198 flags
|= RTP_FLAG_KEY
;
199 len_off
= avio_rb24(pb
);
200 if (mflags
& 0x20) /**< relative timestamp */
202 if (mflags
& 0x10) /**< has duration */
204 if (mflags
& 0x8) /**< has location ID */
208 if (!(mflags
& 0x40)) {
210 * If 0x40 is not set, the len_off field specifies an offset
211 * of this packet's payload data in the complete (reassembled)
212 * ASF packet. This is used to spread one ASF packet over
213 * multiple RTP packets.
215 if (asf
->pktbuf
&& len_off
!= avio_tell(asf
->pktbuf
)) {
217 avio_close_dyn_buf(asf
->pktbuf
, &p
);
221 if (!len_off
&& !asf
->pktbuf
&&
222 (res
= avio_open_dyn_buf(&asf
->pktbuf
)) < 0)
227 avio_write(asf
->pktbuf
, buf
+ off
, len
- off
);
228 avio_skip(pb
, len
- off
);
229 if (!(flags
& RTP_FLAG_MARKER
))
231 out_len
= avio_close_dyn_buf(asf
->pktbuf
, &asf
->buf
);
235 * If 0x40 is set, the len_off field specifies the length of
236 * the next ASF packet that can be read from this payload
237 * data alone. This is commonly the same as the payload size,
238 * but could be less in case of packet splitting (i.e.
239 * multiple ASF packets in one RTP packet).
242 int cur_len
= start_off
+ len_off
- off
;
243 int prev_len
= out_len
;
245 if (FFMIN(cur_len
, len
- off
) < 0)
247 if ((res
= av_reallocp(&asf
->buf
, out_len
)) < 0)
249 memcpy(asf
->buf
+ prev_len
, buf
+ off
,
250 FFMIN(cur_len
, len
- off
));
251 avio_skip(pb
, cur_len
);
255 init_packetizer(pb
, asf
->buf
, out_len
);
256 pb
->pos
+= rt
->asf_pb_pos
;
258 rt
->asf_ctx
->pb
= pb
;
264 res
= ff_read_packet(rt
->asf_ctx
, pkt
);
265 rt
->asf_pb_pos
= avio_tell(pb
);
268 for (i
= 0; i
< s
->nb_streams
; i
++) {
269 if (s
->streams
[i
]->id
== rt
->asf_ctx
->streams
[pkt
->stream_index
]->id
) {
270 pkt
->stream_index
= i
;
271 return 1; // FIXME: return 0 if last packet
277 return res
== 1 ? -1 : res
;
280 static PayloadContext
*asfrtp_new_context(void)
282 return av_mallocz(sizeof(PayloadContext
));
285 static void asfrtp_free_context(PayloadContext
*asf
)
289 avio_close_dyn_buf(asf
->pktbuf
, &p
);
297 #define RTP_ASF_HANDLER(n, s, t) \
298 RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
301 .codec_id = AV_CODEC_ID_NONE, \
302 .parse_sdp_a_line = asfrtp_parse_sdp_line, \
303 .alloc = asfrtp_new_context, \
304 .free = asfrtp_free_context, \
305 .parse_packet = asfrtp_parse_packet, \
308 RTP_ASF_HANDLER(asf_pfv
, "x-asf-pf", AVMEDIA_TYPE_VIDEO
);
309 RTP_ASF_HANDLER(asf_pfa
, "x-asf-pf", AVMEDIA_TYPE_AUDIO
);