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 libavformat/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/get_bits.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 "rtpdec.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(codec, AV_LOG_DEBUG, "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(codec, AV_LOG_ERROR,
  91                    "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(codec, AV_LOG_DEBUG,
 109                    "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(codec, AV_LOG_ERROR, "Unable to allocate memory for extradata!");
 154                 }
 155             }
 156         }
 157         av_log(codec, AV_LOG_DEBUG, "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(AVFormatContext *ctx,
 163                               PayloadContext *data,
 164                               AVStream *st,
 165                               AVPacket * pkt,
 166                               uint32_t * timestamp,
 167                               const uint8_t * buf,
 168                               int len, int flags)
 169 {
 170     uint8_t nal = buf[0];
 171     uint8_t type = (nal & 0x1f);
 172     int result= 0;
 173     uint8_t start_sequence[]= {0, 0, 1};
 174
 175 #ifdef DEBUG
 176     assert(data);
 177     assert(data->cookie == MAGIC_COOKIE);
 178 #endif
 179     assert(buf);
 180
 181     if (type >= 1 && type <= 23)
 182         type = 1;              // simplify the case. (these are all the nal types used internally by the h264 codec)
 183     switch (type) {
 184     case 0:                    // undefined;
 185         result= -1;
 186         break;
 187
 188     case 1:
 189         av_new_packet(pkt, len+sizeof(start_sequence));
 190         memcpy(pkt->data, start_sequence, sizeof(start_sequence));
 191         memcpy(pkt->data+sizeof(start_sequence), buf, len);
 192 #ifdef DEBUG
 193         data->packet_types_received[nal & 0x1f]++;
 194 #endif
 195         break;
 196
 197     case 24:                   // STAP-A (one packet, multiple nals)
 198         // consume the STAP-A NAL
 199         buf++;
 200         len--;
 201         // first we are going to figure out the total size....
 202         {
 203             int pass= 0;
 204             int total_length= 0;
 205             uint8_t *dst= NULL;
 206
 207             for(pass= 0; pass<2; pass++) {
 208                 const uint8_t *src= buf;
 209                 int src_len= len;
 210
 211                 do {
 212                     uint16_t nal_size = AV_RB16(src); // this going to be a problem if unaligned (can it be?)
 213
 214                     // consume the length of the aggregate...
 215                     src += 2;
 216                     src_len -= 2;
 217
 218                     if (nal_size <= src_len) {
 219                         if(pass==0) {
 220                             // counting...
 221                             total_length+= sizeof(start_sequence)+nal_size;
 222                         } else {
 223                             // copying
 224                             assert(dst);
 225                             memcpy(dst, start_sequence, sizeof(start_sequence));
 226                             dst+= sizeof(start_sequence);
 227                             memcpy(dst, src, nal_size);
 228 #ifdef DEBUG
 229                             data->packet_types_received[*src & 0x1f]++;
 230 #endif
 231                             dst+= nal_size;
 232                         }
 233                     } else {
 234                         av_log(ctx, AV_LOG_ERROR,
 235                                "nal size exceeds length: %d %d\n", nal_size, src_len);
 236                     }
 237
 238                     // eat what we handled...
 239                     src += nal_size;
 240                     src_len -= nal_size;
 241
 242                     if (src_len < 0)
 243                         av_log(ctx, AV_LOG_ERROR,
 244                                "Consumed more bytes than we got! (%d)\n", src_len);
 245                 } while (src_len > 2);      // because there could be rtp padding..
 246
 247                 if(pass==0) {
 248                     // now we know the total size of the packet (with the start sequences added)
 249                     av_new_packet(pkt, total_length);
 250                     dst= pkt->data;
 251                 } else {
 252                     assert(dst-pkt->data==total_length);
 253                 }
 254             }
 255         }
 256         break;
 257
 258     case 25:                   // STAP-B
 259     case 26:                   // MTAP-16
 260     case 27:                   // MTAP-24
 261     case 29:                   // FU-B
 262         av_log(ctx, AV_LOG_ERROR,
 263                "Unhandled type (%d) (See RFC for implementation details\n",
 264                type);
 265         result= -1;
 266         break;
 267
 268     case 28:                   // FU-A (fragmented nal)
 269         buf++;
 270         len--;                  // skip the fu_indicator
 271         {
 272             // these are the same as above, we just redo them here for clarity...
 273             uint8_t fu_indicator = nal;
 274             uint8_t fu_header = *buf;   // read the fu_header.
 275             uint8_t start_bit = fu_header >> 7;
 276 //            uint8_t end_bit = (fu_header & 0x40) >> 6;
 277             uint8_t nal_type = (fu_header & 0x1f);
 278             uint8_t reconstructed_nal;
 279
 280             // reconstruct this packet's true nal; only the data follows..
 281             reconstructed_nal = fu_indicator & (0xe0);  // the original nal forbidden bit and NRI are stored in this packet's nal;
 282             reconstructed_nal |= nal_type;
 283
 284             // skip the fu_header...
 285             buf++;
 286             len--;
 287
 288 #ifdef DEBUG
 289             if (start_bit)
 290                 data->packet_types_received[nal_type]++;
 291 #endif
 292             if(start_bit) {
 293                 // copy in the start sequence, and the reconstructed nal....
 294                 av_new_packet(pkt, sizeof(start_sequence)+sizeof(nal)+len);
 295                 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
 296                 pkt->data[sizeof(start_sequence)]= reconstructed_nal;
 297                 memcpy(pkt->data+sizeof(start_sequence)+sizeof(nal), buf, len);
 298             } else {
 299                 av_new_packet(pkt, len);
 300                 memcpy(pkt->data, buf, len);
 301             }
 302         }
 303         break;
 304
 305     case 30:                   // undefined
 306     case 31:                   // undefined
 307     default:
 308         av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)", type);
 309         result= -1;
 310         break;
 311     }
 312
 313     pkt->stream_index = st->index;
 314
 315     return result;
 316 }
 317
 318 /* ---------------- public code */
 319 static PayloadContext *h264_new_context(void)
 320 {
 321     PayloadContext *data =
 322         av_mallocz(sizeof(PayloadContext) +
 323                    FF_INPUT_BUFFER_PADDING_SIZE);
 324
 325     if (data) {
 326         data->cookie = MAGIC_COOKIE;
 327     }
 328
 329     return data;
 330 }
 331
 332 static void h264_free_context(PayloadContext *data)
 333 {
 334 #ifdef DEBUG
 335     int ii;
 336
 337     for (ii = 0; ii < 32; ii++) {
 338         if (data->packet_types_received[ii])
 339             av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
 340                    data->packet_types_received[ii], ii);
 341     }
 342 #endif
 343
 344     assert(data);
 345     assert(data->cookie == MAGIC_COOKIE);
 346
 347     // avoid stale pointers (assert)
 348     data->cookie = DEAD_COOKIE;
 349
 350     // and clear out this...
 351     av_free(data);
 352 }
 353
 354 static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
 355                                PayloadContext *h264_data, const char *line)
 356 {
 357     AVStream *stream = s->streams[st_index];
 358     AVCodecContext *codec = stream->codec;
 359     const char *p = line;
 360
 361     assert(h264_data->cookie == MAGIC_COOKIE);
 362
 363     if (av_strstart(p, "framesize:", &p)) {
 364         char buf1[50];
 365         char *dst = buf1;
 366
 367         // remove the protocol identifier..
 368         while (*p && *p == ' ') p++; // strip spaces.
 369         while (*p && *p != ' ') p++; // eat protocol identifier
 370         while (*p && *p == ' ') p++; // strip trailing spaces.
 371         while (*p && *p != '-' && (buf1 - dst) < sizeof(buf1) - 1) {
 372             *dst++ = *p++;
 373         }
 374         *dst = '\0';
 375
 376         // a='framesize:96 320-240'
 377         // set our parameters..
 378         codec->width = atoi(buf1);
 379         codec->height = atoi(p + 1); // skip the -
 380         codec->pix_fmt = PIX_FMT_YUV420P;
 381     } else if (av_strstart(p, "fmtp:", &p)) {
 382         char attr[256];
 383         char value[4096];
 384
 385         // remove the protocol identifier..
 386         while (*p && *p == ' ') p++; // strip spaces.
 387         while (*p && *p != ' ') p++; // eat protocol identifier
 388         while (*p && *p == ' ') p++; // strip trailing spaces.
 389
 390         /* loop on each attribute */
 391         while (rtsp_next_attr_and_value
 392                (&p, attr, sizeof(attr), value, sizeof(value))) {
 393             /* grab the codec extra_data from the config parameter of the fmtp line */
 394             sdp_parse_fmtp_config_h264(stream, h264_data, attr, value);
 395         }
 396     } else if (av_strstart(p, "cliprect:", &p)) {
 397         // could use this if we wanted.
 398     }
 399
 400     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)
 401
 402     return 0;                   // keep processing it the normal way...
 403 }
 404
 405 /**
 406 This is the structure for expanding on the dynamic rtp protocols (makes everything static. yay!)
 407 */
 408 RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
 409     .enc_name         = "H264",
 410     .codec_type       = CODEC_TYPE_VIDEO,
 411     .codec_id         = CODEC_ID_H264,
 412     .parse_sdp_a_line = parse_h264_sdp_line,
 413     .open             = h264_new_context,
 414     .close            = h264_free_context,
 415     .parse_packet     = h264_handle_packet
 416 };