FFmpeg
rtpdec_qt.c
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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 
42 static av_cold int qt_rtp_init(AVFormatContext *ctx, int st_index,
43  PayloadContext *qt)
44 {
45  qt->pkt = av_packet_alloc();
46  if (!qt->pkt)
47  return AVERROR(ENOMEM);
48 
49  return 0;
50 }
51 
53  AVStream *st, AVPacket *pkt,
54  uint32_t *timestamp, const uint8_t *buf,
55  int len, uint16_t seq, int flags)
56 {
57  FFIOContext pb0;
58  AVIOContext *const pb = &pb0.pub;
59  GetBitContext gb;
60  int packing_scheme, has_payload_desc, has_packet_info, alen,
61  has_marker_bit = flags & RTP_FLAG_MARKER,
62  keyframe, ret;
63 
64  if (qt->remaining) {
65  int num = qt->pkt->size / qt->bytes_per_frame;
66 
67  if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
68  return ret;
69  pkt->stream_index = st->index;
70  pkt->flags = qt->pkt->flags;
71  memcpy(pkt->data,
72  &qt->pkt->data[(num - qt->remaining) * qt->bytes_per_frame],
73  qt->bytes_per_frame);
74  if (--qt->remaining == 0) {
75  av_freep(&qt->pkt->data);
76  qt->pkt->size = 0;
77  }
78  return qt->remaining > 0;
79  }
80 
81  /**
82  * The RTP payload is described in:
83  * http://developer.apple.com/quicktime/icefloe/dispatch026.html
84  */
85  ret = init_get_bits(&gb, buf, len << 3);
86  if (ret < 0)
87  return ret;
88  ffio_init_context(&pb0, (uint8_t*)buf, len, 0, NULL, NULL, NULL, NULL);
89 
90  if (len < 4)
91  return AVERROR_INVALIDDATA;
92 
93  skip_bits(&gb, 4); // version
94  if ((packing_scheme = get_bits(&gb, 2)) == 0)
95  return AVERROR_INVALIDDATA;
96  keyframe = get_bits1(&gb);
97  has_payload_desc = get_bits1(&gb);
98  has_packet_info = get_bits1(&gb);
99  skip_bits(&gb, 23); // reserved:7, cache payload info:1, payload ID:15
100 
101  if (has_payload_desc) {
102  int data_len, pos, is_start, is_finish;
103  uint32_t tag;
104 
105  pos = get_bits_count(&gb) >> 3;
106  if (pos + 12 > len)
107  return AVERROR_INVALIDDATA;
108 
109  skip_bits(&gb, 2); // has non-I-frames:1, is sparse:1
110  is_start = get_bits1(&gb);
111  is_finish = get_bits1(&gb);
112  if (!is_start || !is_finish) {
113  avpriv_request_sample(s, "RTP-X-QT with payload description "
114  "split over several packets");
115  return AVERROR_PATCHWELCOME;
116  }
117  skip_bits(&gb, 12); // reserved
118  data_len = get_bits(&gb, 16);
119 
120  avio_seek(pb, pos + 4, SEEK_SET);
121  tag = avio_rl32(pb);
122  if ((st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
123  tag != MKTAG('v','i','d','e')) ||
125  tag != MKTAG('s','o','u','n')))
126  return AVERROR_INVALIDDATA;
127  avpriv_set_pts_info(st, 32, 1, avio_rb32(pb));
128 
129  if (pos + data_len > len)
130  return AVERROR_INVALIDDATA;
131  /* TLVs */
132  while (avio_tell(pb) + 4 < pos + data_len) {
133  int tlv_len = avio_rb16(pb);
134  tag = avio_rl16(pb);
135  if (avio_tell(pb) + tlv_len > pos + data_len)
136  return AVERROR_INVALIDDATA;
137 
138 #define MKTAG16(a,b) MKTAG(a,b,0,0)
139  switch (tag) {
140  case MKTAG16('s','d'): {
141  MOVStreamContext *msc;
142  void *priv_data = st->priv_data;
143  int nb_streams = s->nb_streams;
144  MOVContext *mc = av_mallocz(sizeof(*mc));
145  if (!mc)
146  return AVERROR(ENOMEM);
147  mc->fc = s;
148  st->priv_data = msc = av_mallocz(sizeof(MOVStreamContext));
149  if (!msc) {
150  av_free(mc);
151  st->priv_data = priv_data;
152  return AVERROR(ENOMEM);
153  }
154  /* ff_mov_read_stsd_entries updates stream s->nb_streams-1,
155  * so set it temporarily to indicate which stream to update. */
156  s->nb_streams = st->index + 1;
158  qt->bytes_per_frame = msc->bytes_per_frame;
159  av_free(msc);
160  av_free(mc);
161  st->priv_data = priv_data;
162  s->nb_streams = nb_streams;
163  break;
164  }
165  default:
166  avio_skip(pb, tlv_len);
167  break;
168  }
169  }
170 
171  /* 32-bit alignment */
172  avio_skip(pb, ((avio_tell(pb) + 3) & ~3) - avio_tell(pb));
173  } else
174  avio_seek(pb, 4, SEEK_SET);
175 
176  if (has_packet_info) {
177  avpriv_request_sample(s, "RTP-X-QT with packet-specific info");
178  return AVERROR_PATCHWELCOME;
179  }
180 
181  alen = len - avio_tell(pb);
182  if (alen <= 0)
183  return AVERROR_INVALIDDATA;
184 
185  switch (packing_scheme) {
186  case 3: /* one data packet spread over 1 or multiple RTP packets */
187  if (qt->pkt->size > 0 && qt->timestamp == *timestamp) {
188  int err;
189  if ((err = av_reallocp(&qt->pkt->data, qt->pkt->size + alen +
191  qt->pkt->size = 0;
192  return err;
193  }
194  } else {
195  av_freep(&qt->pkt->data);
196  av_packet_unref(qt->pkt);
198  if (!qt->pkt->data)
199  return AVERROR(ENOMEM);
200  qt->pkt->size = 0;
201  qt->timestamp = *timestamp;
202  }
203  memcpy(qt->pkt->data + qt->pkt->size, buf + avio_tell(pb), alen);
204  qt->pkt->size += alen;
205  if (has_marker_bit) {
206  int ret = av_packet_from_data(pkt, qt->pkt->data, qt->pkt->size);
207  if (ret < 0)
208  return ret;
209 
210  qt->pkt->size = 0;
211  qt->pkt->data = NULL;
212  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
213  pkt->stream_index = st->index;
214  memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
215  return 0;
216  }
217  return AVERROR(EAGAIN);
218 
219  case 1: /* constant packet size, multiple packets per RTP packet */
220  if (qt->bytes_per_frame == 0 ||
221  alen % qt->bytes_per_frame != 0)
222  return AVERROR_INVALIDDATA; /* wrongly padded */
223  qt->remaining = (alen / qt->bytes_per_frame) - 1;
224  if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
225  return ret;
226  memcpy(pkt->data, buf + avio_tell(pb), qt->bytes_per_frame);
227  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
228  pkt->stream_index = st->index;
229  if (qt->remaining > 0) {
230  av_freep(&qt->pkt->data);
231  qt->pkt->data = av_realloc(NULL, qt->remaining * qt->bytes_per_frame);
232  if (!qt->pkt->data) {
234  return AVERROR(ENOMEM);
235  }
236  qt->pkt->size = qt->remaining * qt->bytes_per_frame;
237  memcpy(qt->pkt->data,
238  buf + avio_tell(pb) + qt->bytes_per_frame,
239  qt->remaining * qt->bytes_per_frame);
240  qt->pkt->flags = pkt->flags;
241  return 1;
242  }
243  return 0;
244 
245  default: /* unimplemented */
246  avpriv_request_sample(NULL, "RTP-X-QT with packing scheme 2");
247  return AVERROR_PATCHWELCOME;
248  }
249 }
250 
251 static void qt_rtp_close(PayloadContext *qt)
252 {
253  av_freep(&qt->pkt->data);
254  av_packet_free(&qt->pkt);
255 }
256 
257 #define RTP_QT_HANDLER(m, n, s, t) \
258 const RTPDynamicProtocolHandler ff_ ## m ## _rtp_ ## n ## _handler = { \
259  .enc_name = s, \
260  .codec_type = t, \
261  .codec_id = AV_CODEC_ID_NONE, \
262  .priv_data_size = sizeof(PayloadContext), \
263  .init = qt_rtp_init, \
264  .close = qt_rtp_close, \
265  .parse_packet = qt_rtp_parse_packet, \
266 }
267 
268 RTP_QT_HANDLER(qt, vid, "X-QT", AVMEDIA_TYPE_VIDEO);
270 RTP_QT_HANDLER(quicktime, vid, "X-QUICKTIME", AVMEDIA_TYPE_VIDEO);
271 RTP_QT_HANDLER(quicktime, aud, "X-QUICKTIME", AVMEDIA_TYPE_AUDIO);
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:422
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:58
AVStream::priv_data
void * priv_data
Definition: avformat.h:964
MOVStreamContext
Definition: isom.h:166
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:219
RTP_FLAG_MARKER
#define RTP_FLAG_MARKER
RTP marker bit was set for this packet.
Definition: rtpdec.h:94
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFIOContext
Definition: avio_internal.h:29
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:429
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:649
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:73
PayloadContext::timestamp
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
skip_bits
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:467
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:763
GetBitContext
Definition: get_bits.h:61
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:510
MOVContext
Definition: isom.h:265
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:745
qt_rtp_init
static av_cold int qt_rtp_init(AVFormatContext *ctx, int st_index, PayloadContext *qt)
Definition: rtpdec_qt.c:42
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:792
pkt
AVPacket * pkt
Definition: movenc.c:59
av_cold
#define av_cold
Definition: attributes.h:90
s
#define s(width, name)
Definition: cbs_vp9.c:256
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:97
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
PayloadContext::bytes_per_frame
int bytes_per_frame
Definition: rtpdec_qt.c:38
ctx
AVFormatContext * ctx
Definition: movenc.c:48
get_bits.h
nb_streams
static int nb_streams
Definition: ffprobe.c:308
AVFormatContext
Format I/O context.
Definition: avformat.h:1216
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
av_realloc
void * av_realloc(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory.
Definition: mem.c:153
isom.h
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
rtpdec.h
aud
static int FUNC() aud(CodedBitstreamContext *ctx, RWContext *rw, H264RawAUD *current)
Definition: cbs_h264_syntax_template.c:842
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:761
av_packet_from_data
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:171
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
AVPacket::size
int size
Definition: packet.h:375
FFIOContext::pub
AVIOContext pub
Definition: avio_internal.h:30
av_reallocp
int av_reallocp(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory through a pointer to a pointer.
Definition: mem.c:186
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:380
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:62
rtp.h
PayloadContext::pkt
AVPacket * pkt
Definition: rtpdec_qt.c:37
RTP_QT_HANDLER
#define RTP_QT_HANDLER(m, n, s, t)
Definition: rtpdec_qt.c:257
MOVStreamContext::bytes_per_frame
unsigned int bytes_per_frame
Definition: isom.h:204
avio_internal.h
ffio_init_context
void ffio_init_context(FFIOContext *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
av_mallocz
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:264
len
int len
Definition: vorbis_enc_data.h:426
tag
uint32_t tag
Definition: movenc.c:1647
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:948
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:262
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:777
qt_rtp_close
static void qt_rtp_close(PayloadContext *qt)
Definition: rtpdec_qt.c:251
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: defs.h:40
AVStream::index
int index
stream index in AVFormatContext
Definition: avformat.h:956
PayloadContext::remaining
int remaining
Definition: rtpdec_qt.c:38
AVPacket::stream_index
int stream_index
Definition: packet.h:376
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:349
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:36
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
MKTAG16
#define MKTAG16(a, b)
AVPacket
This structure stores compressed data.
Definition: packet.h:351
ff_mov_read_stsd_entries
int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries)
Definition: mov.c:2547
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
qt_rtp_parse_packet
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:52
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
PayloadContext
RTP/JPEG specific private data.
Definition: rdt.c:83
mc
#define mc
Definition: vf_colormatrix.c:102