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  AVIOContext pb;
58  GetBitContext gb;
59  int packing_scheme, has_payload_desc, has_packet_info, alen,
60  has_marker_bit = flags & RTP_FLAG_MARKER,
61  keyframe, ret;
62 
63  if (qt->remaining) {
64  int num = qt->pkt->size / qt->bytes_per_frame;
65 
66  if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
67  return ret;
68  pkt->stream_index = st->index;
69  pkt->flags = qt->pkt->flags;
70  memcpy(pkt->data,
71  &qt->pkt->data[(num - qt->remaining) * qt->bytes_per_frame],
72  qt->bytes_per_frame);
73  if (--qt->remaining == 0) {
74  av_freep(&qt->pkt->data);
75  qt->pkt->size = 0;
76  }
77  return qt->remaining > 0;
78  }
79 
80  /**
81  * The RTP payload is described in:
82  * http://developer.apple.com/quicktime/icefloe/dispatch026.html
83  */
84  init_get_bits(&gb, buf, len << 3);
85  ffio_init_context(&pb, (uint8_t*)buf, len, 0, NULL, NULL, NULL, NULL);
86 
87  if (len < 4)
88  return AVERROR_INVALIDDATA;
89 
90  skip_bits(&gb, 4); // version
91  if ((packing_scheme = get_bits(&gb, 2)) == 0)
92  return AVERROR_INVALIDDATA;
93  keyframe = get_bits1(&gb);
94  has_payload_desc = get_bits1(&gb);
95  has_packet_info = get_bits1(&gb);
96  skip_bits(&gb, 23); // reserved:7, cache payload info:1, payload ID:15
97 
98  if (has_payload_desc) {
99  int data_len, pos, is_start, is_finish;
100  uint32_t tag;
101 
102  pos = get_bits_count(&gb) >> 3;
103  if (pos + 12 > len)
104  return AVERROR_INVALIDDATA;
105 
106  skip_bits(&gb, 2); // has non-I-frames:1, is sparse:1
107  is_start = get_bits1(&gb);
108  is_finish = get_bits1(&gb);
109  if (!is_start || !is_finish) {
110  avpriv_request_sample(s, "RTP-X-QT with payload description "
111  "split over several packets");
112  return AVERROR_PATCHWELCOME;
113  }
114  skip_bits(&gb, 12); // reserved
115  data_len = get_bits(&gb, 16);
116 
117  avio_seek(&pb, pos + 4, SEEK_SET);
118  tag = avio_rl32(&pb);
119  if ((st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
120  tag != MKTAG('v','i','d','e')) ||
122  tag != MKTAG('s','o','u','n')))
123  return AVERROR_INVALIDDATA;
124  avpriv_set_pts_info(st, 32, 1, avio_rb32(&pb));
125 
126  if (pos + data_len > len)
127  return AVERROR_INVALIDDATA;
128  /* TLVs */
129  while (avio_tell(&pb) + 4 < pos + data_len) {
130  int tlv_len = avio_rb16(&pb);
131  tag = avio_rl16(&pb);
132  if (avio_tell(&pb) + tlv_len > pos + data_len)
133  return AVERROR_INVALIDDATA;
134 
135 #define MKTAG16(a,b) MKTAG(a,b,0,0)
136  switch (tag) {
137  case MKTAG16('s','d'): {
138  MOVStreamContext *msc;
139  void *priv_data = st->priv_data;
140  int nb_streams = s->nb_streams;
141  MOVContext *mc = av_mallocz(sizeof(*mc));
142  if (!mc)
143  return AVERROR(ENOMEM);
144  mc->fc = s;
145  st->priv_data = msc = av_mallocz(sizeof(MOVStreamContext));
146  if (!msc) {
147  av_free(mc);
148  st->priv_data = priv_data;
149  return AVERROR(ENOMEM);
150  }
151  /* ff_mov_read_stsd_entries updates stream s->nb_streams-1,
152  * so set it temporarily to indicate which stream to update. */
153  s->nb_streams = st->index + 1;
154  ff_mov_read_stsd_entries(mc, &pb, 1);
155  qt->bytes_per_frame = msc->bytes_per_frame;
156  av_free(msc);
157  av_free(mc);
158  st->priv_data = priv_data;
159  s->nb_streams = nb_streams;
160  break;
161  }
162  default:
163  avio_skip(&pb, tlv_len);
164  break;
165  }
166  }
167 
168  /* 32-bit alignment */
169  avio_skip(&pb, ((avio_tell(&pb) + 3) & ~3) - avio_tell(&pb));
170  } else
171  avio_seek(&pb, 4, SEEK_SET);
172 
173  if (has_packet_info) {
174  avpriv_request_sample(s, "RTP-X-QT with packet-specific info");
175  return AVERROR_PATCHWELCOME;
176  }
177 
178  alen = len - avio_tell(&pb);
179  if (alen <= 0)
180  return AVERROR_INVALIDDATA;
181 
182  switch (packing_scheme) {
183  case 3: /* one data packet spread over 1 or multiple RTP packets */
184  if (qt->pkt->size > 0 && qt->timestamp == *timestamp) {
185  int err;
186  if ((err = av_reallocp(&qt->pkt->data, qt->pkt->size + alen +
188  qt->pkt->size = 0;
189  return err;
190  }
191  } else {
192  av_freep(&qt->pkt->data);
193  av_packet_unref(qt->pkt);
195  if (!qt->pkt->data)
196  return AVERROR(ENOMEM);
197  qt->pkt->size = 0;
198  qt->timestamp = *timestamp;
199  }
200  memcpy(qt->pkt->data + qt->pkt->size, buf + avio_tell(&pb), alen);
201  qt->pkt->size += alen;
202  if (has_marker_bit) {
203  int ret = av_packet_from_data(pkt, qt->pkt->data, qt->pkt->size);
204  if (ret < 0)
205  return ret;
206 
207  qt->pkt->size = 0;
208  qt->pkt->data = NULL;
209  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
210  pkt->stream_index = st->index;
211  memset(pkt->data + pkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
212  return 0;
213  }
214  return AVERROR(EAGAIN);
215 
216  case 1: /* constant packet size, multiple packets per RTP packet */
217  if (qt->bytes_per_frame == 0 ||
218  alen % qt->bytes_per_frame != 0)
219  return AVERROR_INVALIDDATA; /* wrongly padded */
220  qt->remaining = (alen / qt->bytes_per_frame) - 1;
221  if ((ret = av_new_packet(pkt, qt->bytes_per_frame)) < 0)
222  return ret;
223  memcpy(pkt->data, buf + avio_tell(&pb), qt->bytes_per_frame);
224  pkt->flags = keyframe ? AV_PKT_FLAG_KEY : 0;
225  pkt->stream_index = st->index;
226  if (qt->remaining > 0) {
227  av_freep(&qt->pkt->data);
228  qt->pkt->data = av_realloc(NULL, qt->remaining * qt->bytes_per_frame);
229  if (!qt->pkt->data) {
231  return AVERROR(ENOMEM);
232  }
233  qt->pkt->size = qt->remaining * qt->bytes_per_frame;
234  memcpy(qt->pkt->data,
235  buf + avio_tell(&pb) + qt->bytes_per_frame,
236  qt->remaining * qt->bytes_per_frame);
237  qt->pkt->flags = pkt->flags;
238  return 1;
239  }
240  return 0;
241 
242  default: /* unimplemented */
243  avpriv_request_sample(NULL, "RTP-X-QT with packing scheme 2");
244  return AVERROR_PATCHWELCOME;
245  }
246 }
247 
248 static void qt_rtp_close(PayloadContext *qt)
249 {
250  av_freep(&qt->pkt->data);
251  av_packet_free(&qt->pkt);
252 }
253 
254 #define RTP_QT_HANDLER(m, n, s, t) \
255 const RTPDynamicProtocolHandler ff_ ## m ## _rtp_ ## n ## _handler = { \
256  .enc_name = s, \
257  .codec_type = t, \
258  .codec_id = AV_CODEC_ID_NONE, \
259  .priv_data_size = sizeof(PayloadContext), \
260  .init = qt_rtp_init, \
261  .close = qt_rtp_close, \
262  .parse_packet = qt_rtp_parse_packet, \
263 }
264 
265 RTP_QT_HANDLER(qt, vid, "X-QT", AVMEDIA_TYPE_VIDEO);
267 RTP_QT_HANDLER(quicktime, vid, "X-QUICKTIME", AVMEDIA_TYPE_VIDEO);
268 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:403
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:56
AVStream::priv_data
void * priv_data
Definition: avformat.h:841
MKTAG
#define MKTAG(a, b, c, d)
Definition: common.h:478
MOVStreamContext
Definition: isom.h:158
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:93
AVPacket::data
uint8_t * data
Definition: packet.h:365
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:396
init_get_bits
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
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:70
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
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:557
MOVContext
Definition: isom.h:246
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:717
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:764
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:257
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:94
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:288
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
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:759
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:733
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:161
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
ffio_init_context
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:78
AVPacket::size
int size
Definition: packet.h:366
avpriv_set_pts_info
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:4799
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:167
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:371
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:59
rtp.h
PayloadContext::pkt
AVPacket * pkt
Definition: rtpdec_qt.c:37
av_realloc
void * av_realloc(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory.
Definition: mem.c:134
RTP_QT_HANDLER
#define RTP_QT_HANDLER(m, n, s, t)
Definition: rtpdec_qt.c:254
MOVStreamContext::bytes_per_frame
unsigned int bytes_per_frame
Definition: isom.h:196
avio_internal.h
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:243
len
int len
Definition: vorbis_enc_data.h:426
tag
uint32_t tag
Definition: movenc.c:1594
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:832
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:243
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:749
qt_rtp_close
static void qt_rtp_close(PayloadContext *qt)
Definition: rtpdec_qt.c:248
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
AV_INPUT_BUFFER_PADDING_SIZE
#define AV_INPUT_BUFFER_PADDING_SIZE
Definition: avcodec.h:192
AVStream::index
int index
stream index in AVFormatContext
Definition: avformat.h:833
PayloadContext::remaining
int remaining
Definition: rtpdec_qt.c:38
AVPacket::stream_index
int stream_index
Definition: packet.h:367
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:327
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:39
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
MKTAG16
#define MKTAG16(a, b)
AVPacket
This structure stores compressed data.
Definition: packet.h:342
ff_mov_read_stsd_entries
int ff_mov_read_stsd_entries(MOVContext *c, AVIOContext *pb, int entries)
Definition: mov.c:2466
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
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:59
PayloadContext
RTP/JPEG specific private data.
Definition: rdt.c:83
mc
#define mc
Definition: vf_colormatrix.c:102