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