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rtpdec_asf.c
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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 
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;
107  int len = strlen(p) * 6 / 8;
108  char *buf = av_mallocz(len);
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) {
121  }
122 
123  if (!(iformat = av_find_input_format("asf")))
125 
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 {
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  */
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 
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);
const ff_asf_guid ff_asf_header
Definition: asf.c:23
#define NULL
Definition: coverity.c:32
int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
Parse a Windows Media Server-specific SDP line.
Definition: rtpdec_asf.c:100
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:147
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1272
unsigned char * buf_end
End of the data, may be less than buffer+buffer_size if the read function returned less data than req...
Definition: avio.h:211
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4493
RTP/JPEG specific private data.
Definition: rdt.c:83
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:216
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
uint64_t_TMPL AV_RL64
Definition: bytestream.h:87
static AVPacket pkt
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1260
Format I/O context.
Definition: avformat.h:1325
static int rtp_asf_fix_header(uint8_t *buf, int len)
From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not contain any padding...
Definition: rtpdec_asf.c:46
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
enum AVStreamParseType need_parsing
Definition: avformat.h:1063
int id
Format-specific stream ID.
Definition: avformat.h:883
int ff_copy_whiteblacklists(AVFormatContext *dst, AVFormatContext *src)
Copies the whilelists from one context to the other.
Definition: utils.c:145
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1393
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:132
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:204
#define av_log(a,...)
Private data for the RTSP demuxer.
Definition: rtsp.h:218
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
Copy the contents of src to dst.
Definition: utils.c:4059
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1539
static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
Definition: rtpdec_asf.c:191
#define RTP_FLAG_MARKER
RTP marker bit was set for this packet.
Definition: rtpdec.h:93
static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
The following code is basically a buffered AVIOContext, with the added benefit of returning -EAGAIN (...
Definition: rtpdec_asf.c:86
#define AVERROR(e)
Definition: error.h:43
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values. ...
Definition: dict.c:202
Definition: graph2dot.c:48
simple assert() macros that are a bit more flexible than ISO C assert().
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:589
uint64_t asf_pb_pos
cache for position of the asf demuxer, since we load a new data packet in the bytecontext for each in...
Definition: rtsp.h:311
AVIOContext * pktbuf
Definition: rtpdec_asf.c:182
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1381
AVDictionary * opts
Definition: movenc.c:50
AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:164
AVFormatContext * asf_ctx
The following are used for RTP/ASF streams.
Definition: rtsp.h:307
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:744
#define FFMIN(a, b)
Definition: common.h:96
static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index, PayloadContext *asf, const char *line)
Definition: rtpdec_asf.c:153
static void init_packetizer(AVIOContext *pb, uint8_t *buf, int len)
Definition: rtpdec_asf.c:91
int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
Read a transport packet from a media file.
Definition: utils.c:734
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1300
uint8_t ff_asf_guid[16]
Definition: riff.h:89
Stream structure.
Definition: avformat.h:876
static AVInputFormat * iformat
Definition: ffprobe.c:231
const ff_asf_guid ff_asf_file_header
Definition: asf.c:27
AVIOContext * pb
I/O context.
Definition: avformat.h:1367
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:563
void * buf
Definition: avisynth_c.h:553
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:69
uint8_t * buf
the temporary storage buffer
Definition: rtpdec_asf.c:183
static void asfrtp_close_context(PayloadContext *asf)
Definition: rtpdec_asf.c:296
static int flags
Definition: cpu.c:47
#define AVERROR_DEMUXER_NOT_FOUND
Demuxer not found.
Definition: error.h:53
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
#define RTP_ASF_HANDLER(n, s, t)
Definition: rtpdec_asf.c:302
int ffio_init_context(AVIOContext *s, unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int(*read_packet)(void *opaque, uint8_t *buf, int buf_size), int(*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t(*seek)(void *opaque, int64_t offset, int whence))
Definition: aviobuf.c:81
int av_reallocp(void *ptr, size_t size)
Allocate or reallocate a block of memory.
Definition: mem.c:187
int64_t pos
position in the file of the current buffer
Definition: avio.h:220
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4103
#define av_free(p)
int eof_reached
true if eof reached
Definition: avio.h:222
int len
void * priv_data
Format private data.
Definition: avformat.h:1353
int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
Decode a base64-encoded string.
Definition: base64.c:79
int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:471
#define av_freep(p)
AVCodecParameters * codecpar
Definition: avformat.h:1228
int stream_index
Definition: avcodec.h:1590
AVIOContext pb
Definition: rtpdec_asf.c:182
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1565
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:252
#define AV_WL32(p, v)
Definition: intreadwrite.h:426