FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
rtpdec_qt.c
Go to the documentation of this file.
1 /*
2  * RTP/Quicktime support.
3  * Copyright (c) 2009 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 Quicktime-style RTP support
25  * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26  */
27 
28 #include "avformat.h"
29 #include "internal.h"
30 #include "avio_internal.h"
31 #include "rtp.h"
32 #include "rtpdec.h"
33 #include "isom.h"
34 #include "libavcodec/get_bits.h"
35 
36 struct PayloadContext {
39  uint32_t timestamp;
40 };
41 
43  AVStream *st, AVPacket *pkt,
44  uint32_t *timestamp, const uint8_t *buf,
45  int len, uint16_t seq, int flags)
46 {
47  AVIOContext pb;
48  GetBitContext gb;
49  int packing_scheme, has_payload_desc, has_packet_info, alen,
50  has_marker_bit = flags & RTP_FLAG_MARKER,
51  keyframe;
52 
53  if (qt->remaining) {
54  int num = qt->pkt.size / qt->bytes_per_frame;
55 
56  if (av_new_packet(pkt, qt->bytes_per_frame))
57  return AVERROR(ENOMEM);
58  pkt->stream_index = st->index;
59  pkt->flags = qt->pkt.flags;
60  memcpy(pkt->data,
61  &qt->pkt.data[(num - qt->remaining) * qt->bytes_per_frame],
62  qt->bytes_per_frame);
63  if (--qt->remaining == 0) {
64  av_freep(&qt->pkt.data);
65  qt->pkt.size = 0;
66  }
67  return qt->remaining > 0;
68  }
69 
70  /**
71  * The RTP payload is described in:
72  * http://developer.apple.com/quicktime/icefloe/dispatch026.html
73  */
74  init_get_bits(&gb, buf, len << 3);
75  ffio_init_context(&pb, (uint8_t*)buf, len, 0, NULL, NULL, NULL, NULL);
76 
77  if (len < 4)
78  return AVERROR_INVALIDDATA;
79 
80  skip_bits(&gb, 4); // version
81  if ((packing_scheme = get_bits(&gb, 2)) == 0)
82  return AVERROR_INVALIDDATA;
83  keyframe = get_bits1(&gb);
84  has_payload_desc = get_bits1(&gb);
85  has_packet_info = get_bits1(&gb);
86  skip_bits(&gb, 23); // reserved:7, cache payload info:1, payload ID:15
87 
88  if (has_payload_desc) {
89  int data_len, pos, is_start, is_finish;
90  uint32_t tag;
91 
92  pos = get_bits_count(&gb) >> 3;
93  if (pos + 12 > len)
94  return AVERROR_INVALIDDATA;
95 
96  skip_bits(&gb, 2); // has non-I frames:1, is sparse:1
97  is_start = get_bits1(&gb);
98  is_finish = get_bits1(&gb);
99  if (!is_start || !is_finish) {
100  avpriv_request_sample(s, "RTP-X-QT with payload description "
101  "split over several packets");
102  return AVERROR_PATCHWELCOME;
103  }
104  skip_bits(&gb, 12); // reserved
105  data_len = get_bits(&gb, 16);
106 
107  avio_seek(&pb, pos + 4, SEEK_SET);
108  tag = avio_rl32(&pb);
109  if ((st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
110  tag != MKTAG('v','i','d','e')) ||
112  tag != MKTAG('s','o','u','n')))
113  return AVERROR_INVALIDDATA;
114  avpriv_set_pts_info(st, 32, 1, avio_rb32(&pb));
115 
116  if (pos + data_len > len)
117  return AVERROR_INVALIDDATA;
118  /* TLVs */
119  while (avio_tell(&pb) + 4 < pos + data_len) {
120  int tlv_len = avio_rb16(&pb);
121  tag = avio_rl16(&pb);
122  if (avio_tell(&pb) + tlv_len > pos + data_len)
123  return AVERROR_INVALIDDATA;
124 
125 #define MKTAG16(a,b) MKTAG(a,b,0,0)
126  switch (tag) {
127  case MKTAG16('s','d'): {
128  MOVStreamContext *msc;
129  void *priv_data = st->priv_data;
130  int nb_streams = s->nb_streams;
131  MOVContext *mc = av_mallocz(sizeof(*mc));
132  if (!mc)
133  return AVERROR(ENOMEM);
134  mc->fc = s;
135  st->priv_data = msc = av_mallocz(sizeof(MOVStreamContext));
136  if (!msc) {
137  av_free(mc);
138  st->priv_data = priv_data;
139  return AVERROR(ENOMEM);
140  }
141  /* ff_mov_read_stsd_entries updates stream s->nb_streams-1,
142  * so set it temporarily to indicate which stream to update. */
143  s->nb_streams = st->index + 1;
144  ff_mov_read_stsd_entries(mc, &pb, 1);
145  qt->bytes_per_frame = msc->bytes_per_frame;
146  av_free(msc);
147  av_free(mc);
148  st->priv_data = priv_data;
149  s->nb_streams = nb_streams;
150  break;
151  }
152  default:
153  avio_skip(&pb, tlv_len);
154  break;
155  }
156  }
157 
158  /* 32-bit alignment */
159  avio_skip(&pb, ((avio_tell(&pb) + 3) & ~3) - avio_tell(&pb));
160  } else
161  avio_seek(&pb, 4, SEEK_SET);
162 
163  if (has_packet_info) {
164  avpriv_request_sample(s, "RTP-X-QT with packet-specific info");
165  return AVERROR_PATCHWELCOME;
166  }
167 
168  alen = len - avio_tell(&pb);
169  if (alen <= 0)
170  return AVERROR_INVALIDDATA;
171 
172  switch (packing_scheme) {
173  case 3: /* one data packet spread over 1 or multiple RTP packets */
174  if (qt->pkt.size > 0 && qt->timestamp == *timestamp) {
175  int err;
176  if ((err = av_reallocp(&qt->pkt.data, qt->pkt.size + alen +
178  qt->pkt.size = 0;
179  return err;
180  }
181  } else {
182  av_freep(&qt->pkt.data);
183  av_init_packet(&qt->pkt);
185  if (!qt->pkt.data)
186  return AVERROR(ENOMEM);
187  qt->pkt.size = 0;
188  qt->timestamp = *timestamp;
189  }
190  memcpy(qt->pkt.data + qt->pkt.size, buf + avio_tell(&pb), alen);
191  qt->pkt.size += alen;
192  if (has_marker_bit) {
193  int ret = av_packet_from_data(pkt, qt->pkt.data, qt->pkt.size);
194  if (ret < 0)
195  return ret;
196 
197  qt->pkt.size = 0;
198  qt->pkt.data = NULL;
199  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
200  pkt->stream_index = st->index;
201  memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
202  return 0;
203  }
204  return AVERROR(EAGAIN);
205 
206  case 1: /* constant packet size, multiple packets per RTP packet */
207  if (qt->bytes_per_frame == 0 ||
208  alen % qt->bytes_per_frame != 0)
209  return AVERROR_INVALIDDATA; /* wrongly padded */
210  qt->remaining = (alen / qt->bytes_per_frame) - 1;
211  if (av_new_packet(pkt, qt->bytes_per_frame))
212  return AVERROR(ENOMEM);
213  memcpy(pkt->data, buf + avio_tell(&pb), qt->bytes_per_frame);
214  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
215  pkt->stream_index = st->index;
216  if (qt->remaining > 0) {
217  av_freep(&qt->pkt.data);
218  qt->pkt.data = av_realloc(NULL, qt->remaining * qt->bytes_per_frame);
219  if (!qt->pkt.data) {
220  av_packet_unref(pkt);
221  return AVERROR(ENOMEM);
222  }
223  qt->pkt.size = qt->remaining * qt->bytes_per_frame;
224  memcpy(qt->pkt.data,
225  buf + avio_tell(&pb) + qt->bytes_per_frame,
226  qt->remaining * qt->bytes_per_frame);
227  qt->pkt.flags = pkt->flags;
228  return 1;
229  }
230  return 0;
231 
232  default: /* unimplemented */
233  avpriv_request_sample(NULL, "RTP-X-QT with packing scheme 2");
234  return AVERROR_PATCHWELCOME;
235  }
236 }
237 
238 static void qt_rtp_close(PayloadContext *qt)
239 {
240  av_freep(&qt->pkt.data);
241 }
242 
243 #define RTP_QT_HANDLER(m, n, s, t) \
244 RTPDynamicProtocolHandler ff_ ## m ## _rtp_ ## n ## _handler = { \
245  .enc_name = s, \
246  .codec_type = t, \
247  .codec_id = AV_CODEC_ID_NONE, \
248  .priv_data_size = sizeof(PayloadContext), \
249  .close = qt_rtp_close, \
250  .parse_packet = qt_rtp_parse_packet, \
251 }
252 
253 RTP_QT_HANDLER(qt, vid, "X-QT", AVMEDIA_TYPE_VIDEO);
254 RTP_QT_HANDLER(qt, aud, "X-QT", AVMEDIA_TYPE_AUDIO);
255 RTP_QT_HANDLER(quicktime, vid, "X-QUICKTIME", AVMEDIA_TYPE_VIDEO);
256 RTP_QT_HANDLER(quicktime, aud, "X-QUICKTIME", AVMEDIA_TYPE_AUDIO);
AVPacket pkt
Definition: rtpdec_qt.c:37
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:260
int bytes_per_frame
Definition: rtpdec_qt.c:38
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:4404
RTP/JPEG specific private data.
Definition: rdt.c:83
static int qt_rtp_parse_packet(AVFormatContext *s, PayloadContext *qt, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
Definition: rtpdec_qt.c:42
int index
stream index in AVFormatContext
Definition: avformat.h:877
int size
Definition: avcodec.h:1578
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:213
void * priv_data
Definition: avformat.h:891
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:287
static AVPacket pkt
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:688
#define MKTAG16(a, b)
Format I/O context.
Definition: avformat.h:1319
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t
static int nb_streams
Definition: ffprobe.c:253
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:703
int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size)
Initialize a reference-counted packet from av_malloc()ed data.
Definition: avpacket.c:137
uint8_t * data
Definition: avcodec.h:1577
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:212
uint32_t tag
Definition: movenc.c:1353
bitstream reader API header.
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:447
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1609
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
#define RTP_FLAG_MARKER
RTP marker bit was set for this packet.
Definition: rtpdec.h:93
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:672
#define AVERROR(e)
Definition: error.h:43
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3911
AVFormatContext * fc
Definition: isom.h:189
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1583
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1375
static void qt_rtp_close(PayloadContext *qt)
Definition: rtpdec_qt.c:238
#define RTP_QT_HANDLER(m, n, s, t)
Definition: rtpdec_qt.c:243
#define mc
Stream structure.
Definition: avformat.h:876
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:549
void * buf
Definition: avisynth_c.h:553
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:312
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:305
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:418
int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries)
Definition: mov.c:2193
static int flags
Definition: cpu.c:47
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:656
Main libavformat public API header.
unsigned int bytes_per_frame
Definition: isom.h:147
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
void * av_realloc(void *ptr, size_t size)
Allocate or reallocate a block of memory.
Definition: mem.c:145
int av_reallocp(void *ptr, size_t size)
Allocate or reallocate a block of memory.
Definition: mem.c:187
void av_init_packet(AVPacket *pkt)
Initialize optional fields of a packet with default values.
Definition: avpacket.c:33
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:728
#define av_free(p)
int len
#define av_freep(p)
AVCodecParameters * codecpar
Definition: avformat.h:1006
int stream_index
Definition: avcodec.h:1579
#define MKTAG(a, b, c, d)
Definition: common.h:342
This structure stores compressed data.
Definition: avcodec.h:1554
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