libavformat/rtp_h264.c

   1 /*
   2  * RTP H264 Protocol (RFC3984)
   3  * Copyright (c) 2006 Ryan Martell.
   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 rtp_h264.c
  24  * @brief H.264 / RTP Code (RFC3984)
  25  * @author Ryan Martell <rdm4@martellventures.com>
  26  *
  27  * @note Notes:
  28  * Notes:
  29  * This currently supports packetization mode:
  30  * Single Nal Unit Mode (0), or
  31  * Non-Interleaved Mode (1).  It currently does not support
  32  * Interleaved Mode (2). (This requires implementing STAP-B, MTAP16, MTAP24, FU-B packet types)
  33  *
  34  * @note TODO:
  35  * 1) RTCP sender reports for udp streams are required..
  36  *
  37  */
  38
  39 #include "libavutil/base64.h"
  40 #include "libavutil/avstring.h"
  41 #include "libavcodec/bitstream.h"
  42 #include "avformat.h"
  43 #include "mpegts.h"
  44
  45 #include <unistd.h>
  46 #include "network.h"
  47 #include <assert.h>
  48
  49 #include "rtp_internal.h"
  50 #include "rtp_h264.h"
  51
  52 /**
  53     RTP/H264 specific private data.
  54 */
  55 struct PayloadContext {
  56     unsigned long cookie;       ///< sanity check, to make sure we get the pointer we're expecting.
  57
  58     //sdp setup parameters
  59     uint8_t profile_idc;        ///< from the sdp setup parameters.
  60     uint8_t profile_iop;        ///< from the sdp setup parameters.
  61     uint8_t level_idc;          ///< from the sdp setup parameters.
  62     int packetization_mode;     ///< from the sdp setup parameters.
  63 #ifdef DEBUG
  64     int packet_types_received[32];
  65 #endif
  66 };
  67
  68 #define MAGIC_COOKIE (0xdeadbeef)       ///< Cookie for the extradata; to verify we are what we think we are, and that we haven't been freed.
  69 #define DEAD_COOKIE (0xdeaddead)        ///< Cookie for the extradata; once it is freed.
  70
  71 /* ---------------- private code */
  72 static void sdp_parse_fmtp_config_h264(AVStream * stream,
  73                                        PayloadContext * h264_data,
  74                                        char *attr, char *value)
  75 {
  76     AVCodecContext *codec = stream->codec;
  77     assert(codec->codec_id == CODEC_ID_H264);
  78     assert(h264_data != NULL);
  79
  80     if (!strcmp(attr, "packetization-mode")) {
  81         av_log(NULL, AV_LOG_DEBUG, "H.264/RTP Packetization Mode: %d\n", atoi(value));
  82         h264_data->packetization_mode = atoi(value);
  83         /*
  84            Packetization Mode:
  85            0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
  86            1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
  87            2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A), and 29 (FU-B) are allowed.
  88          */
  89         if (h264_data->packetization_mode > 1)
  90             av_log(stream, AV_LOG_ERROR,
  91                    "H.264/RTP Interleaved RTP mode is not supported yet.");
  92     } else if (!strcmp(attr, "profile-level-id")) {
  93         if (strlen(value) == 6) {
  94             char buffer[3];
  95             // 6 characters=3 bytes, in hex.
  96             uint8_t profile_idc;
  97             uint8_t profile_iop;
  98             uint8_t level_idc;
  99
 100             buffer[0] = value[0]; buffer[1] = value[1]; buffer[2] = '\0';
 101             profile_idc = strtol(buffer, NULL, 16);
 102             buffer[0] = value[2]; buffer[1] = value[3];
 103             profile_iop = strtol(buffer, NULL, 16);
 104             buffer[0] = value[4]; buffer[1] = value[5];
 105             level_idc = strtol(buffer, NULL, 16);
 106
 107             // set the parameters...
 108             av_log(NULL, AV_LOG_DEBUG,
 109                    "H.264/RTP Profile IDC: %x Profile IOP: %x Level: %x\n",
 110                    profile_idc, profile_iop, level_idc);
 111             h264_data->profile_idc = profile_idc;
 112             h264_data->profile_iop = profile_iop;
 113             h264_data->level_idc = level_idc;
 114         }
 115     } else  if (!strcmp(attr, "sprop-parameter-sets")) {
 116         uint8_t start_sequence[]= { 0, 0, 1 };
 117         codec->extradata_size= 0;
 118         codec->extradata= NULL;
 119
 120         while (*value) {
 121             char base64packet[1024];
 122             uint8_t decoded_packet[1024];
 123             uint32_t packet_size;
 124             char *dst = base64packet;
 125
 126             while (*value && *value != ','
 127                    && (dst - base64packet) < sizeof(base64packet) - 1) {
 128                 *dst++ = *value++;
 129             }
 130             *dst++ = '\0';
 131
 132             if (*value == ',')
 133                 value++;
 134
 135             packet_size= av_base64_decode(decoded_packet, base64packet, sizeof(decoded_packet));
 136             if (packet_size) {
 137                 uint8_t *dest= av_malloc(packet_size+sizeof(start_sequence)+codec->extradata_size);
 138                 if(dest)
 139                 {
 140                     if(codec->extradata_size)
 141                     {
 142                         // av_realloc?
 143                         memcpy(dest, codec->extradata, codec->extradata_size);
 144                         av_free(codec->extradata);
 145                     }
 146
 147                     memcpy(dest+codec->extradata_size, start_sequence, sizeof(start_sequence));
 148                     memcpy(dest+codec->extradata_size+sizeof(start_sequence), decoded_packet, packet_size);
 149
 150                     codec->extradata= dest;
 151                     codec->extradata_size+= sizeof(start_sequence)+packet_size;
 152                 } else {
 153                     av_log(NULL, AV_LOG_ERROR, "H.264/RTP Unable to allocate memory for extradata!");
 154                 }
 155             }
 156         }
 157         av_log(NULL, AV_LOG_DEBUG, "H.264/RTP Extradata set to %p (size: %d)!", codec->extradata, codec->extradata_size);
 158     }
 159 }
 160
 161 // return 0 on packet, no more left, 1 on packet, 1 on partial packet...
 162 static int h264_handle_packet(PayloadContext *data,
 163                               AVStream *st,
 164                               AVPacket * pkt,
 165                               uint32_t * timestamp,
 166                               const uint8_t * buf,
 167                               int len, int flags)
 168 {
 169     uint8_t nal = buf[0];
 170     uint8_t type = (nal & 0x1f);
 171     int result= 0;
 172     uint8_t start_sequence[]= {0, 0, 1};
 173
 174 #ifdef DEBUG
 175     assert(data);
 176     assert(data->cookie == MAGIC_COOKIE);
 177 #endif
 178     assert(buf);
 179
 180     if (type >= 1 && type <= 23)
 181         type = 1;              // simplify the case. (these are all the nal types used internally by the h264 codec)
 182     switch (type) {
 183     case 0:                    // undefined;
 184         result= -1;
 185         break;
 186
 187     case 1:
 188         av_new_packet(pkt, len+sizeof(start_sequence));
 189         memcpy(pkt->data, start_sequence, sizeof(start_sequence));
 190         memcpy(pkt->data+sizeof(start_sequence), buf, len);
 191 #ifdef DEBUG
 192         data->packet_types_received[nal & 0x1f]++;
 193 #endif
 194         break;
 195
 196     case 24:                   // STAP-A (one packet, multiple nals)
 197         // consume the STAP-A NAL
 198         buf++;
 199         len--;
 200         // first we are going to figure out the total size....
 201         {
 202             int pass= 0;
 203             int total_length= 0;
 204             uint8_t *dst= NULL;
 205
 206             for(pass= 0; pass<2; pass++) {
 207                 const uint8_t *src= buf;
 208                 int src_len= len;
 209
 210                 do {
 211                     uint16_t nal_size = AV_RB16(src); // this going to be a problem if unaligned (can it be?)
 212
 213                     // consume the length of the aggregate...
 214                     src += 2;
 215                     src_len -= 2;
 216
 217                     if (nal_size <= src_len) {
 218                         if(pass==0) {
 219                             // counting...
 220                             total_length+= sizeof(start_sequence)+nal_size;
 221                         } else {
 222                             // copying
 223                             assert(dst);
 224                             memcpy(dst, start_sequence, sizeof(start_sequence));
 225                             dst+= sizeof(start_sequence);
 226                             memcpy(dst, src, nal_size);
 227 #ifdef DEBUG
 228                             data->packet_types_received[*src & 0x1f]++;
 229 #endif
 230                             dst+= nal_size;
 231                         }
 232                     } else {
 233                         av_log(NULL, AV_LOG_ERROR,
 234                                "nal size exceeds length: %d %d\n", nal_size, src_len);
 235                     }
 236
 237                     // eat what we handled...
 238                     src += nal_size;
 239                     src_len -= nal_size;
 240
 241                     if (src_len < 0)
 242                         av_log(NULL, AV_LOG_ERROR,
 243                                "Consumed more bytes than we got! (%d)\n", src_len);
 244                 } while (src_len > 2);      // because there could be rtp padding..
 245
 246                 if(pass==0) {
 247                     // now we know the total size of the packet (with the start sequences added)
 248                     av_new_packet(pkt, total_length);
 249                     dst= pkt->data;
 250                 } else {
 251                     assert(dst-pkt->data==total_length);
 252                 }
 253             }
 254         }
 255         break;
 256
 257     case 25:                   // STAP-B
 258     case 26:                   // MTAP-16
 259     case 27:                   // MTAP-24
 260     case 29:                   // FU-B
 261         av_log(NULL, AV_LOG_ERROR,
 262                "Unhandled type (%d) (See RFC for implementation details\n",
 263                type);
 264         result= -1;
 265         break;
 266
 267     case 28:                   // FU-A (fragmented nal)
 268         buf++;
 269         len--;                  // skip the fu_indicator
 270         {
 271             // these are the same as above, we just redo them here for clarity...
 272             uint8_t fu_indicator = nal;
 273             uint8_t fu_header = *buf;   // read the fu_header.
 274             uint8_t start_bit = fu_header >> 7;
 275 //            uint8_t end_bit = (fu_header & 0x40) >> 6;
 276             uint8_t nal_type = (fu_header & 0x1f);
 277             uint8_t reconstructed_nal;
 278
 279             // reconstruct this packet's true nal; only the data follows..
 280             reconstructed_nal = fu_indicator & (0xe0);  // the original nal forbidden bit and NRI are stored in this packet's nal;
 281             reconstructed_nal |= nal_type;
 282
 283             // skip the fu_header...
 284             buf++;
 285             len--;
 286
 287 #ifdef DEBUG
 288             if (start_bit)
 289                 data->packet_types_received[nal_type]++;
 290 #endif
 291             if(start_bit) {
 292                 // copy in the start sequence, and the reconstructed nal....
 293                 av_new_packet(pkt, sizeof(start_sequence)+sizeof(nal)+len);
 294                 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
 295                 pkt->data[sizeof(start_sequence)]= reconstructed_nal;
 296                 memcpy(pkt->data+sizeof(start_sequence)+sizeof(nal), buf, len);
 297             } else {
 298                 av_new_packet(pkt, len);
 299                 memcpy(pkt->data, buf, len);
 300             }
 301         }
 302         break;
 303
 304     case 30:                   // undefined
 305     case 31:                   // undefined
 306     default:
 307         av_log(NULL, AV_LOG_ERROR, "Undefined type (%d)", type);
 308         result= -1;
 309         break;
 310     }
 311
 312     return result;
 313 }
 314
 315 /* ---------------- public code */
 316 static PayloadContext *h264_new_extradata(void)
 317 {
 318     PayloadContext *data =
 319         av_mallocz(sizeof(PayloadContext) +
 320                    FF_INPUT_BUFFER_PADDING_SIZE);
 321
 322     if (data) {
 323         data->cookie = MAGIC_COOKIE;
 324     }
 325
 326     return data;
 327 }
 328
 329 static void h264_free_extradata(PayloadContext *data)
 330 {
 331 #ifdef DEBUG
 332     int ii;
 333
 334     for (ii = 0; ii < 32; ii++) {
 335         if (data->packet_types_received[ii])
 336             av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
 337                    data->packet_types_received[ii], ii);
 338     }
 339 #endif
 340
 341     assert(data);
 342     assert(data->cookie == MAGIC_COOKIE);
 343
 344     // avoid stale pointers (assert)
 345     data->cookie = DEAD_COOKIE;
 346
 347     // and clear out this...
 348     av_free(data);
 349 }
 350
 351 static int parse_h264_sdp_line(AVStream * stream, PayloadContext *h264_data,
 352                                const char *line)
 353 {
 354     AVCodecContext *codec = stream->codec;
 355     const char *p = line;
 356
 357     assert(h264_data->cookie == MAGIC_COOKIE);
 358
 359     if (av_strstart(p, "framesize:", &p)) {
 360         char buf1[50];
 361         char *dst = buf1;
 362
 363         // remove the protocol identifier..
 364         while (*p && *p == ' ') p++; // strip spaces.
 365         while (*p && *p != ' ') p++; // eat protocol identifier
 366         while (*p && *p == ' ') p++; // strip trailing spaces.
 367         while (*p && *p != '-' && (buf1 - dst) < sizeof(buf1) - 1) {
 368             *dst++ = *p++;
 369         }
 370         *dst = '\0';
 371
 372         // a='framesize:96 320-240'
 373         // set our parameters..
 374         codec->width = atoi(buf1);
 375         codec->height = atoi(p + 1); // skip the -
 376         codec->pix_fmt = PIX_FMT_YUV420P;
 377     } else if (av_strstart(p, "fmtp:", &p)) {
 378         char attr[256];
 379         char value[4096];
 380
 381         // remove the protocol identifier..
 382         while (*p && *p == ' ') p++; // strip spaces.
 383         while (*p && *p != ' ') p++; // eat protocol identifier
 384         while (*p && *p == ' ') p++; // strip trailing spaces.
 385
 386         /* loop on each attribute */
 387         while (rtsp_next_attr_and_value
 388                (&p, attr, sizeof(attr), value, sizeof(value))) {
 389             /* grab the codec extra_data from the config parameter of the fmtp line */
 390             sdp_parse_fmtp_config_h264(stream, h264_data, attr, value);
 391         }
 392     } else if (av_strstart(p, "cliprect:", &p)) {
 393         // could use this if we wanted.
 394     }
 395
 396     av_set_pts_info(stream, 33, 1, 90000);      // 33 should be right, because the pts is 64 bit? (done elsewhere; this is a one time thing)
 397
 398     return 0;                   // keep processing it the normal way...
 399 }
 400
 401 /**
 402 This is the structure for expanding on the dynamic rtp protocols (makes everything static. yay!)
 403 */
 404 RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
 405     "H264",
 406     CODEC_TYPE_VIDEO,
 407     CODEC_ID_H264,
 408     parse_h264_sdp_line,
 409     h264_new_extradata,
 410     h264_free_extradata,
 411     h264_handle_packet
 412 };