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rtpdec_hevc.c
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1 /*
2  * RTP parser for HEVC/H.265 payload format (draft version 6)
3  * Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>
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 #include "libavutil/avassert.h"
24 #include "libavutil/avstring.h"
25 #include "libavutil/base64.h"
26 #include "libavcodec/get_bits.h"
27 
28 #include "avformat.h"
29 #include "rtpdec.h"
30 #include "rtpdec_formats.h"
31 
32 #define RTP_HEVC_PAYLOAD_HEADER_SIZE 2
33 #define RTP_HEVC_FU_HEADER_SIZE 1
34 #define RTP_HEVC_DONL_FIELD_SIZE 2
35 #define RTP_HEVC_DOND_FIELD_SIZE 1
36 #define RTP_HEVC_AP_NALU_LENGTH_FIELD_SIZE 2
37 #define HEVC_SPECIFIED_NAL_UNIT_TYPES 48
38 
39 /* SDP out-of-band signaling data */
40 struct PayloadContext {
41  int using_donl_field;
42  int profile_id;
43  uint8_t *sps, *pps, *vps, *sei;
44  int sps_size, pps_size, vps_size, sei_size;
45 };
46 
47 static const uint8_t start_sequence[] = { 0x00, 0x00, 0x00, 0x01 };
48 
49 static av_cold int hevc_sdp_parse_fmtp_config(AVFormatContext *s,
50  AVStream *stream,
51  PayloadContext *hevc_data,
52  const char *attr, const char *value)
53 {
54  /* profile-space: 0-3 */
55  /* profile-id: 0-31 */
56  if (!strcmp(attr, "profile-id")) {
57  hevc_data->profile_id = atoi(value);
58  av_dlog(s, "SDP: found profile-id: %d\n", hevc_data->profile_id);
59  }
60 
61  /* tier-flag: 0-1 */
62  /* level-id: 0-255 */
63  /* interop-constraints: [base16] */
64  /* profile-compatibility-indicator: [base16] */
65  /* sprop-sub-layer-id: 0-6, defines highest possible value for TID, default: 6 */
66  /* recv-sub-layer-id: 0-6 */
67  /* max-recv-level-id: 0-255 */
68  /* tx-mode: MSM,SSM */
69  /* sprop-vps: [base64] */
70  /* sprop-sps: [base64] */
71  /* sprop-pps: [base64] */
72  /* sprop-sei: [base64] */
73  if (!strcmp(attr, "sprop-vps") || !strcmp(attr, "sprop-sps") ||
74  !strcmp(attr, "sprop-pps") || !strcmp(attr, "sprop-sei")) {
75  uint8_t **data_ptr = NULL;
76  int *size_ptr = NULL;
77  if (!strcmp(attr, "sprop-vps")) {
78  data_ptr = &hevc_data->vps;
79  size_ptr = &hevc_data->vps_size;
80  } else if (!strcmp(attr, "sprop-sps")) {
81  data_ptr = &hevc_data->sps;
82  size_ptr = &hevc_data->sps_size;
83  } else if (!strcmp(attr, "sprop-pps")) {
84  data_ptr = &hevc_data->pps;
85  size_ptr = &hevc_data->pps_size;
86  } else if (!strcmp(attr, "sprop-sei")) {
87  data_ptr = &hevc_data->sei;
88  size_ptr = &hevc_data->sei_size;
89  } else
90  av_assert0(0);
91 
92  ff_h264_parse_sprop_parameter_sets(s, data_ptr,
93  size_ptr, value);
94  }
95 
96  /* max-lsr, max-lps, max-cpb, max-dpb, max-br, max-tr, max-tc */
97  /* max-fps */
98 
99  /* sprop-max-don-diff: 0-32767
100 
101  When the RTP stream depends on one or more other RTP
102  streams (in this case tx-mode MUST be equal to "MSM" and
103  MSM is in use), this parameter MUST be present and the
104  value MUST be greater than 0.
105  */
106  if (!strcmp(attr, "sprop-max-don-diff")) {
107  if (atoi(value) > 0)
108  hevc_data->using_donl_field = 1;
109  av_dlog(s, "Found sprop-max-don-diff in SDP, DON field usage is: %d\n",
110  hevc_data->using_donl_field);
111  }
112 
113  /* sprop-depack-buf-nalus: 0-32767 */
114  if (!strcmp(attr, "sprop-depack-buf-nalus")) {
115  if (atoi(value) > 0)
116  hevc_data->using_donl_field = 1;
117  av_dlog(s, "Found sprop-depack-buf-nalus in SDP, DON field usage is: %d\n",
118  hevc_data->using_donl_field);
119  }
120 
121  /* sprop-depack-buf-bytes: 0-4294967295 */
122  /* depack-buf-cap */
123  /* sprop-segmentation-id: 0-3 */
124  /* sprop-spatial-segmentation-idc: [base16] */
125  /* dec-parallel-ca: */
126  /* include-dph */
127 
128  return 0;
129 }
130 
131 static av_cold int hevc_parse_sdp_line(AVFormatContext *ctx, int st_index,
132  PayloadContext *hevc_data, const char *line)
133 {
134  AVStream *current_stream;
135  AVCodecContext *codec;
136  const char *sdp_line_ptr = line;
137 
138  if (st_index < 0)
139  return 0;
140 
141  current_stream = ctx->streams[st_index];
142  codec = current_stream->codec;
143 
144  if (av_strstart(sdp_line_ptr, "framesize:", &sdp_line_ptr)) {
145  ff_h264_parse_framesize(codec, sdp_line_ptr);
146  } else if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {
147  int ret = ff_parse_fmtp(ctx, current_stream, hevc_data, sdp_line_ptr,
148  hevc_sdp_parse_fmtp_config);
149  if (hevc_data->vps_size || hevc_data->sps_size ||
150  hevc_data->pps_size || hevc_data->sei_size) {
151  av_freep(&codec->extradata);
152  codec->extradata_size = hevc_data->vps_size + hevc_data->sps_size +
153  hevc_data->pps_size + hevc_data->sei_size;
154  codec->extradata = av_malloc(codec->extradata_size +
155  FF_INPUT_BUFFER_PADDING_SIZE);
156  if (!codec->extradata) {
157  ret = AVERROR(ENOMEM);
158  codec->extradata_size = 0;
159  } else {
160  int pos = 0;
161  memcpy(codec->extradata + pos, hevc_data->vps, hevc_data->vps_size);
162  pos += hevc_data->vps_size;
163  memcpy(codec->extradata + pos, hevc_data->sps, hevc_data->sps_size);
164  pos += hevc_data->sps_size;
165  memcpy(codec->extradata + pos, hevc_data->pps, hevc_data->pps_size);
166  pos += hevc_data->pps_size;
167  memcpy(codec->extradata + pos, hevc_data->sei, hevc_data->sei_size);
168  pos += hevc_data->sei_size;
169  memset(codec->extradata + pos, 0, FF_INPUT_BUFFER_PADDING_SIZE);
170  }
171 
172  av_freep(&hevc_data->vps);
173  av_freep(&hevc_data->sps);
174  av_freep(&hevc_data->pps);
175  av_freep(&hevc_data->sei);
176  hevc_data->vps_size = 0;
177  hevc_data->sps_size = 0;
178  hevc_data->pps_size = 0;
179  hevc_data->sei_size = 0;
180  }
181  return ret;
182  }
183 
184  return 0;
185 }
186 
187 static int hevc_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_hevc_ctx,
188  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
189  const uint8_t *buf, int len, uint16_t seq,
190  int flags)
191 {
192  const uint8_t *rtp_pl = buf;
193  int tid, lid, nal_type;
194  int first_fragment, last_fragment, fu_type;
195  uint8_t new_nal_header[2];
196  int res = 0;
197 
198  /* sanity check for size of input packet: 1 byte payload at least */
199  if (len < RTP_HEVC_PAYLOAD_HEADER_SIZE + 1) {
200  av_log(ctx, AV_LOG_ERROR, "Too short RTP/HEVC packet, got %d bytes\n", len);
201  return AVERROR_INVALIDDATA;
202  }
203 
204  /*
205  * decode the HEVC payload header according to section 4 of draft version 6:
206  *
207  * 0 1
208  * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
209  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
210  * |F| Type | LayerId | TID |
211  * +-------------+-----------------+
212  *
213  * Forbidden zero (F): 1 bit
214  * NAL unit type (Type): 6 bits
215  * NUH layer ID (LayerId): 6 bits
216  * NUH temporal ID plus 1 (TID): 3 bits
217  */
218  nal_type = (buf[0] >> 1) & 0x3f;
219  lid = ((buf[0] << 5) & 0x20) | ((buf[1] >> 3) & 0x1f);
220  tid = buf[1] & 0x07;
221 
222  /* sanity check for correct layer ID */
223  if (lid) {
224  /* future scalable or 3D video coding extensions */
225  avpriv_report_missing_feature(ctx, "Multi-layer HEVC coding\n");
226  return AVERROR_PATCHWELCOME;
227  }
228 
229  /* sanity check for correct temporal ID */
230  if (!tid) {
231  av_log(ctx, AV_LOG_ERROR, "Illegal temporal ID in RTP/HEVC packet\n");
232  return AVERROR_INVALIDDATA;
233  }
234 
235  /* sanity check for correct NAL unit type */
236  if (nal_type > 50) {
237  av_log(ctx, AV_LOG_ERROR, "Unsupported (HEVC) NAL type (%d)\n", nal_type);
238  return AVERROR_INVALIDDATA;
239  }
240 
241  switch (nal_type) {
242  /* video parameter set (VPS) */
243  case 32:
244  /* sequence parameter set (SPS) */
245  case 33:
246  /* picture parameter set (PPS) */
247  case 34:
248  /* supplemental enhancement information (SEI) */
249  case 39:
250  /* single NAL unit packet */
251  default:
252  /* sanity check for size of input packet: 1 byte payload at least */
253  if (len < 1) {
254  av_log(ctx, AV_LOG_ERROR,
255  "Too short RTP/HEVC packet, got %d bytes of NAL unit type %d\n",
256  len, nal_type);
257  return AVERROR_INVALIDDATA;
258  }
259 
260  /* create A/V packet */
261  if ((res = av_new_packet(pkt, sizeof(start_sequence) + len)) < 0)
262  return res;
263  /* A/V packet: copy start sequence */
264  memcpy(pkt->data, start_sequence, sizeof(start_sequence));
265  /* A/V packet: copy NAL unit data */
266  memcpy(pkt->data + sizeof(start_sequence), buf, len);
267 
268  break;
269  /* aggregated packet (AP) - with two or more NAL units */
270  case 48:
271  /* pass the HEVC payload header */
272  buf += RTP_HEVC_PAYLOAD_HEADER_SIZE;
273  len -= RTP_HEVC_PAYLOAD_HEADER_SIZE;
274 
275  /* pass the HEVC DONL field */
276  if (rtp_hevc_ctx->using_donl_field) {
277  buf += RTP_HEVC_DONL_FIELD_SIZE;
278  len -= RTP_HEVC_DONL_FIELD_SIZE;
279  }
280 
281  res = ff_h264_handle_aggregated_packet(ctx, rtp_hevc_ctx, pkt, buf, len,
282  rtp_hevc_ctx->using_donl_field ?
283  RTP_HEVC_DOND_FIELD_SIZE : 0,
284  NULL, 0);
285  if (res < 0)
286  return res;
287  break;
288  /* fragmentation unit (FU) */
289  case 49:
290  /* pass the HEVC payload header */
291  buf += RTP_HEVC_PAYLOAD_HEADER_SIZE;
292  len -= RTP_HEVC_PAYLOAD_HEADER_SIZE;
293 
294  /*
295  * decode the FU header
296  *
297  * 0 1 2 3 4 5 6 7
298  * +-+-+-+-+-+-+-+-+
299  * |S|E| FuType |
300  * +---------------+
301  *
302  * Start fragment (S): 1 bit
303  * End fragment (E): 1 bit
304  * FuType: 6 bits
305  */
306  first_fragment = buf[0] & 0x80;
307  last_fragment = buf[0] & 0x40;
308  fu_type = buf[0] & 0x3f;
309 
310  /* pass the HEVC FU header */
311  buf += RTP_HEVC_FU_HEADER_SIZE;
312  len -= RTP_HEVC_FU_HEADER_SIZE;
313 
314  /* pass the HEVC DONL field */
315  if (rtp_hevc_ctx->using_donl_field) {
316  buf += RTP_HEVC_DONL_FIELD_SIZE;
317  len -= RTP_HEVC_DONL_FIELD_SIZE;
318  }
319 
320  av_dlog(ctx, " FU type %d with %d bytes\n", fu_type, len);
321 
322  /* sanity check for size of input packet: 1 byte payload at least */
323  if (len <= 0) {
324  if (len < 0) {
325  av_log(ctx, AV_LOG_ERROR,
326  "Too short RTP/HEVC packet, got %d bytes of NAL unit type %d\n",
327  len, nal_type);
328  return AVERROR_INVALIDDATA;
329  } else {
330  return AVERROR(EAGAIN);
331  }
332  }
333 
334  if (first_fragment && last_fragment) {
335  av_log(ctx, AV_LOG_ERROR, "Illegal combination of S and E bit in RTP/HEVC packet\n");
336  return AVERROR_INVALIDDATA;
337  }
338 
339  new_nal_header[0] = (rtp_pl[0] & 0x81) | (fu_type << 1);
340  new_nal_header[1] = rtp_pl[1];
341 
342  res = ff_h264_handle_frag_packet(pkt, buf, len, first_fragment,
343  new_nal_header, sizeof(new_nal_header));
344 
345  break;
346  /* PACI packet */
347  case 50:
348  /* Temporal scalability control information (TSCI) */
349  avpriv_report_missing_feature(ctx, "PACI packets for RTP/HEVC\n");
350  res = AVERROR_PATCHWELCOME;
351  break;
352  }
353 
354  pkt->stream_index = st->index;
355 
356  return res;
357 }
358 
359 RTPDynamicProtocolHandler ff_hevc_dynamic_handler = {
360  .enc_name = "H265",
361  .codec_type = AVMEDIA_TYPE_VIDEO,
362  .codec_id = AV_CODEC_ID_HEVC,
363  .need_parsing = AVSTREAM_PARSE_FULL,
364  .priv_data_size = sizeof(PayloadContext),
365  .parse_sdp_a_line = hevc_parse_sdp_line,
366  .parse_packet = hevc_handle_packet,
367 };
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