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rtpdec_qdm2.c
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1 /*
2  * QDesign Music 2 (QDM2) payload for RTP
3  * Copyright (c) 2010 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 RTP support for the QDM2 payload (todo: wiki)
25  * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26  */
27 
28 #include <string.h>
29 #include "libavutil/avassert.h"
30 #include "libavutil/intreadwrite.h"
31 #include "libavcodec/avcodec.h"
32 #include "internal.h"
33 #include "rtp.h"
34 #include "rtpdec.h"
35 #include "rtpdec_formats.h"
36 
37 struct PayloadContext {
38  /** values read from the config header, used as packet headers */
39  //@{
40  int block_type; ///< superblock type, value 2 .. 8
41  int block_size; ///< from extradata, used as pkt length
42  int subpkts_per_block; ///< max. nr. of subpackets to add per output buffer
43  //@}
44 
45  /** Temporary storage for superblock restoring, per packet ID (0x80 total) */
46  //@{
47  uint16_t len[0x80]; ///< how much the temporary buffer is filled
48  uint8_t buf[0x80][0x800]; ///< the temporary storage buffer
49 
50  unsigned int cache; ///< number of data packets that we have cached right now
51  unsigned int n_pkts; ///< number of RTP packets received since last packet output / config
52  uint32_t timestamp; ///< timestamp of next-to-be-returned packet
53  //@}
54 };
55 
56 /**
57  * Parse configuration (basically the codec-specific extradata) from
58  * an RTP config subpacket (starts with 0xff).
59  *
60  * Layout of the config subpacket (in bytes):
61  * 1: 0xFF <- config ID
62  * then an array {
63  * 1: size <- of the current item
64  * 1: item type <- 0 .. 4
65  * size-2: data <- data depends on the item type
66  * }
67  *
68  * Item 0 implies the end of the config subpacket, and has no data.
69  * Item 1 implies a stream configuration without extradata.
70  * Item 2 max. nr. of subpackets per superblock
71  * Item 3 superblock type for the stream
72  * Item 4 implies a stream configuration with extradata (size >= 0x1c).
73  *
74  * @return <0 on error, otherwise the number of bytes parsed from the
75  * input buffer.
76  */
78  const uint8_t *buf, const uint8_t *end)
79 {
80  const uint8_t *p = buf;
81 
82  while (end - p >= 2) {
83  unsigned int item_len = p[0], config_item = p[1];
84 
85  if (item_len < 2 || end - p < item_len || config_item > 4)
86  return AVERROR_INVALIDDATA;
87 
88  switch (config_item) {
89  case 0: /* end of config block */
90  return p - buf + item_len;
91  case 1: /* stream without extradata */
92  /* FIXME: set default qdm->block_size */
93  break;
94  case 2: /**< subpackets per block */
95  if (item_len < 3)
96  return AVERROR_INVALIDDATA;
97  qdm->subpkts_per_block = p[2];
98  break;
99  case 3: /* superblock type */
100  if (item_len < 4)
101  return AVERROR_INVALIDDATA;
102  qdm->block_type = AV_RB16(p + 2);
103  break;
104  case 4: /* stream with extradata */
105  if (item_len < 30)
106  return AVERROR_INVALIDDATA;
107  av_freep(&st->codecpar->extradata);
108  if (ff_alloc_extradata(st->codecpar, 26 + item_len)) {
109  return AVERROR(ENOMEM);
110  }
111  AV_WB32(st->codecpar->extradata, 12);
112  memcpy(st->codecpar->extradata + 4, "frma", 4);
113  memcpy(st->codecpar->extradata + 8, "QDM2", 4);
114  AV_WB32(st->codecpar->extradata + 12, 6 + item_len);
115  memcpy(st->codecpar->extradata + 16, "QDCA", 4);
116  memcpy(st->codecpar->extradata + 20, p + 2, item_len - 2);
117  AV_WB32(st->codecpar->extradata + 18 + item_len, 8);
118  AV_WB32(st->codecpar->extradata + 22 + item_len, 0);
119 
120  qdm->block_size = AV_RB32(p + 26);
121  break;
122  }
123 
124  p += item_len;
125  }
126 
127  return AVERROR(EAGAIN); /* not enough data */
128 }
129 
130 /**
131  * Parse a single subpacket. We store this subpacket in an intermediate
132  * buffer (position depends on the ID (byte[0]). When called, at least
133  * 4 bytes are available for reading (see qdm2_parse_packet()).
134  *
135  * Layout of a single subpacket (RTP packets commonly contain multiple
136  * such subpackets) - length in bytes:
137  * 1: ordering ID <- 0 .. 0x7F
138  * 1: subpacket type <- 0 .. 0x7F; value & 0x80 means subpacket length = 2 bytes, else 1 byte
139  * 1/2: subpacket length <- length of the data following the flags/length fields
140  * if (subpacket type & 0x7F) == 0x7F
141  * 1: subpacket type, higher bits
142  * size: subpacket data
143  *
144  * The subpackets come in randomly, and should be encapsulated into 1
145  * or more superblocks (containing qdm->subpkts_per_block subpackets
146  * each) per RTP packet, in order of ascending "ordering ID", see
147  * qdm2_restore_block().
148  *
149  * @return <0 on error, otherwise the number of bytes parsed from the
150  * input buffer.
151  */
153  const uint8_t *buf, const uint8_t *end)
154 {
155  const uint8_t *p = buf;
156  unsigned int id, len, type, to_copy;
157 
158  /* parse header so we know the size of the header/data */
159  id = *p++;
160  type = *p++;
161  if (type & 0x80) {
162  len = AV_RB16(p);
163  p += 2;
164  type &= 0x7F;
165  } else
166  len = *p++;
167 
168  if (end - p < len + (type == 0x7F) || id >= 0x80)
169  return AVERROR_INVALIDDATA;
170  if (type == 0x7F)
171  type |= *p++ << 8;
172 
173  /* copy data into a temporary buffer */
174  to_copy = FFMIN(len + (p - &buf[1]), 0x800 - qdm->len[id]);
175  memcpy(&qdm->buf[id][qdm->len[id]], buf + 1, to_copy);
176  qdm->len[id] += to_copy;
177 
178  return p + len - buf;
179 }
180 
181 /**
182  * Add a superblock header around a set of subpackets.
183  *
184  * @return <0 on error, else 0.
185  */
187 {
188  int to_copy, n, res, include_csum;
189  uint8_t *p, *csum_pos = NULL;
190 
191  /* create packet to hold subpkts into a superblock */
192  av_assert0(qdm->cache > 0);
193  for (n = 0; n < 0x80; n++)
194  if (qdm->len[n] > 0)
195  break;
196  av_assert0(n < 0x80);
197 
198  if ((res = av_new_packet(pkt, qdm->block_size)) < 0)
199  return res;
200  memset(pkt->data, 0, pkt->size);
201  pkt->stream_index = st->index;
202  p = pkt->data;
203 
204  /* superblock header */
205  if (qdm->len[n] > 0xff) {
206  *p++ = qdm->block_type | 0x80;
207  AV_WB16(p, qdm->len[n]);
208  p += 2;
209  } else {
210  *p++ = qdm->block_type;
211  *p++ = qdm->len[n];
212  }
213  if ((include_csum = (qdm->block_type == 2 || qdm->block_type == 4))) {
214  csum_pos = p;
215  p += 2;
216  }
217 
218  /* subpacket data */
219  to_copy = FFMIN(qdm->len[n], pkt->size - (p - pkt->data));
220  memcpy(p, qdm->buf[n], to_copy);
221  qdm->len[n] = 0;
222 
223  /* checksum header */
224  if (include_csum) {
225  unsigned int total = 0;
226  uint8_t *q;
227 
228  for (q = pkt->data; q < &pkt->data[qdm->block_size]; q++)
229  total += *q;
230  AV_WB16(csum_pos, (uint16_t) total);
231  }
232 
233  return 0;
234 }
235 
236 /** return 0 on packet, no more left, 1 on packet, -1 on partial packet... */
238  AVStream *st, AVPacket *pkt,
239  uint32_t *timestamp,
240  const uint8_t *buf, int len, uint16_t seq,
241  int flags)
242 {
243  int res = AVERROR_INVALIDDATA, n;
244  const uint8_t *end = buf + len, *p = buf;
245 
246  if (len > 0) {
247  if (len < 2)
248  return AVERROR_INVALIDDATA;
249 
250  /* configuration block */
251  if (*p == 0xff) {
252  if (qdm->n_pkts > 0) {
254  "Out of sequence config - dropping queue\n");
255  qdm->n_pkts = 0;
256  memset(qdm->len, 0, sizeof(qdm->len));
257  }
258 
259  if ((res = qdm2_parse_config(qdm, st, ++p, end)) < 0)
260  return res;
261  p += res;
262 
263  /* We set codec_id to AV_CODEC_ID_NONE initially to
264  * delay decoder initialization since extradata is
265  * carried within the RTP stream, not SDP. Here,
266  * by setting codec_id to AV_CODEC_ID_QDM2, we are signalling
267  * to the decoder that it is OK to initialize. */
269  }
270  if (st->codecpar->codec_id == AV_CODEC_ID_NONE)
271  return AVERROR(EAGAIN);
272 
273  /* subpackets */
274  while (end - p >= 4) {
275  if ((res = qdm2_parse_subpacket(qdm, st, p, end)) < 0)
276  return res;
277  p += res;
278  }
279 
280  qdm->timestamp = *timestamp;
281  if (++qdm->n_pkts < qdm->subpkts_per_block)
282  return AVERROR(EAGAIN);
283  qdm->cache = 0;
284  for (n = 0; n < 0x80; n++)
285  if (qdm->len[n] > 0)
286  qdm->cache++;
287  }
288 
289  /* output the subpackets into freshly created superblock structures */
290  if (!qdm->cache || (res = qdm2_restore_block(qdm, st, pkt)) < 0)
291  return res;
292  if (--qdm->cache == 0)
293  qdm->n_pkts = 0;
294 
295  *timestamp = qdm->timestamp;
296  qdm->timestamp = RTP_NOTS_VALUE;
297 
298  return (qdm->cache > 0) ? 1 : 0;
299 }
300 
302  .enc_name = "X-QDM",
303  .codec_type = AVMEDIA_TYPE_AUDIO,
304  .codec_id = AV_CODEC_ID_NONE,
305  .priv_data_size = sizeof(PayloadContext),
307 };
#define NULL
Definition: coverity.c:32
int block_size
from extradata, used as pkt length
Definition: rtpdec_qdm2.c:41
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
enum AVCodecID id
Definition: mxfenc.c:104
unsigned int n_pkts
number of RTP packets received since last packet output / config
Definition: rtpdec_qdm2.c:51
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
RTP/JPEG specific private data.
Definition: rdt.c:83
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
int index
stream index in AVFormatContext
Definition: avformat.h:879
int size
Definition: avcodec.h:1591
static AVPacket pkt
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1327
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
uint8_t * data
Definition: avcodec.h:1590
static int qdm2_parse_subpacket(PayloadContext *qdm, AVStream *st, const uint8_t *buf, const uint8_t *end)
Parse a single subpacket.
Definition: rtpdec_qdm2.c:152
int subpkts_per_block
max. nr. of subpackets to add per output buffer
Definition: rtpdec_qdm2.c:42
#define AV_WB16(p, v)
Definition: intreadwrite.h:405
#define av_log(a,...)
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
static int qdm2_parse_packet(AVFormatContext *s, PayloadContext *qdm, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
return 0 on packet, no more left, 1 on packet, -1 on partial packet...
Definition: rtpdec_qdm2.c:237
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
static int qdm2_parse_config(PayloadContext *qdm, AVStream *st, const uint8_t *buf, const uint8_t *end)
Parse configuration (basically the codec-specific extradata) from an RTP config subpacket (starts wit...
Definition: rtpdec_qdm2.c:77
#define AVERROR(e)
Definition: error.h:43
int block_type
values read from the config header, used as packet headers
Definition: rtpdec_qdm2.c:40
simple assert() macros that are a bit more flexible than ISO C assert().
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3122
#define FFMIN(a, b)
Definition: common.h:96
unsigned int cache
number of data packets that we have cached right now
Definition: rtpdec_qdm2.c:50
int n
Definition: avisynth_c.h:684
Stream structure.
Definition: avformat.h:878
Libavcodec external API header.
static int qdm2_restore_block(PayloadContext *qdm, AVStream *st, AVPacket *pkt)
Add a superblock header around a set of subpackets.
Definition: rtpdec_qdm2.c:186
void * buf
Definition: avisynth_c.h:690
GLint GLenum type
Definition: opengl_enc.c:105
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
uint8_t * buf
the temporary storage buffer
Definition: rtpdec_asf.c:183
RTPDynamicProtocolHandler ff_qdm2_dynamic_handler
Definition: rtpdec_qdm2.c:301
const char * enc_name
Definition: rtpdec.h:116
static int flags
Definition: cpu.c:47
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
Parse a packet, add all split parts to parse_queue.
Definition: utils.c:1336
int len
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3967
#define RTP_NOTS_VALUE
Definition: rtpdec.h:40
#define av_freep(p)
AVCodecParameters * codecpar
Definition: avformat.h:1230
int stream_index
Definition: avcodec.h:1592
This structure stores compressed data.
Definition: avcodec.h:1567