2 * RTP H264 Protocol (RFC3984)
3 * Copyright (c) 2006 Ryan Martell
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * @brief H.264 / RTP Code (RFC3984)
25 * @author Ryan Martell <rdm4@martellventures.com>
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,
36 #include "libavutil/base64.h"
37 #include "libavutil/avstring.h"
38 #include "libavcodec/get_bits.h"
47 #include "rtpdec_formats.h"
49 struct PayloadContext {
50 // sdp setup parameters
54 int packetization_mode;
56 int packet_types_received[32];
60 static int sdp_parse_fmtp_config_h264(AVStream * stream,
61 PayloadContext * h264_data,
62 char *attr, char *value)
64 AVCodecContext *codec = stream->codec;
65 assert(codec->codec_id == CODEC_ID_H264);
66 assert(h264_data != NULL);
68 if (!strcmp(attr, "packetization-mode")) {
69 av_log(codec, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value));
70 h264_data->packetization_mode = atoi(value);
73 * 0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
74 * 1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
75 * 2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A),
76 * and 29 (FU-B) are allowed.
78 if (h264_data->packetization_mode > 1)
79 av_log(codec, AV_LOG_ERROR,
80 "Interleaved RTP mode is not supported yet.");
81 } else if (!strcmp(attr, "profile-level-id")) {
82 if (strlen(value) == 6) {
84 // 6 characters=3 bytes, in hex.
89 buffer[0] = value[0]; buffer[1] = value[1]; buffer[2] = '\0';
90 profile_idc = strtol(buffer, NULL, 16);
91 buffer[0] = value[2]; buffer[1] = value[3];
92 profile_iop = strtol(buffer, NULL, 16);
93 buffer[0] = value[4]; buffer[1] = value[5];
94 level_idc = strtol(buffer, NULL, 16);
96 av_log(codec, AV_LOG_DEBUG,
97 "RTP Profile IDC: %x Profile IOP: %x Level: %x\n",
98 profile_idc, profile_iop, level_idc);
99 h264_data->profile_idc = profile_idc;
100 h264_data->profile_iop = profile_iop;
101 h264_data->level_idc = level_idc;
103 } else if (!strcmp(attr, "sprop-parameter-sets")) {
104 uint8_t start_sequence[] = { 0, 0, 0, 1 };
105 codec->extradata_size= 0;
106 codec->extradata= NULL;
109 char base64packet[1024];
110 uint8_t decoded_packet[1024];
112 char *dst = base64packet;
114 while (*value && *value != ','
115 && (dst - base64packet) < sizeof(base64packet) - 1) {
123 packet_size= av_base64_decode(decoded_packet, base64packet, sizeof(decoded_packet));
124 if (packet_size > 0) {
125 uint8_t *dest = av_malloc(packet_size + sizeof(start_sequence) +
126 codec->extradata_size +
127 FF_INPUT_BUFFER_PADDING_SIZE);
130 if(codec->extradata_size)
132 memcpy(dest, codec->extradata, codec->extradata_size);
133 av_free(codec->extradata);
136 memcpy(dest+codec->extradata_size, start_sequence, sizeof(start_sequence));
137 memcpy(dest+codec->extradata_size+sizeof(start_sequence), decoded_packet, packet_size);
138 memset(dest+codec->extradata_size+sizeof(start_sequence)+
139 packet_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
141 codec->extradata= dest;
142 codec->extradata_size+= sizeof(start_sequence)+packet_size;
144 av_log(codec, AV_LOG_ERROR, "Unable to allocate memory for extradata!");
145 return AVERROR(ENOMEM);
149 av_log(codec, AV_LOG_DEBUG, "Extradata set to %p (size: %d)!", codec->extradata, codec->extradata_size);
154 // return 0 on packet, no more left, 1 on packet, 1 on partial packet
155 static int h264_handle_packet(AVFormatContext *ctx,
156 PayloadContext *data,
159 uint32_t * timestamp,
166 uint8_t start_sequence[] = { 0, 0, 0, 1 };
169 av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
170 return AVERROR_INVALIDDATA;
178 /* Simplify the case (these are all the nal types used internally by
179 * the h264 codec). */
180 if (type >= 1 && type <= 23)
183 case 0: // undefined, but pass them through
185 av_new_packet(pkt, len+sizeof(start_sequence));
186 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
187 memcpy(pkt->data+sizeof(start_sequence), buf, len);
189 data->packet_types_received[nal & 0x1f]++;
193 case 24: // STAP-A (one packet, multiple nals)
194 // consume the STAP-A NAL
197 // first we are going to figure out the total size
203 for(pass= 0; pass<2; pass++) {
204 const uint8_t *src= buf;
207 while (src_len > 2) {
208 uint16_t nal_size = AV_RB16(src);
210 // consume the length of the aggregate
214 if (nal_size <= src_len) {
217 total_length+= sizeof(start_sequence)+nal_size;
221 memcpy(dst, start_sequence, sizeof(start_sequence));
222 dst+= sizeof(start_sequence);
223 memcpy(dst, src, nal_size);
225 data->packet_types_received[*src & 0x1f]++;
230 av_log(ctx, AV_LOG_ERROR,
231 "nal size exceeds length: %d %d\n", nal_size, src_len);
234 // eat what we handled
239 av_log(ctx, AV_LOG_ERROR,
240 "Consumed more bytes than we got! (%d)\n", src_len);
244 /* now we know the total size of the packet (with the
245 * start sequences added) */
246 av_new_packet(pkt, total_length);
249 assert(dst-pkt->data==total_length);
259 av_log(ctx, AV_LOG_ERROR,
260 "Unhandled type (%d) (See RFC for implementation details\n",
262 result = AVERROR(ENOSYS);
265 case 28: // FU-A (fragmented nal)
267 len--; // skip the fu_indicator
269 // these are the same as above, we just redo them here for clarity
270 uint8_t fu_indicator = nal;
271 uint8_t fu_header = *buf;
272 uint8_t start_bit = fu_header >> 7;
273 uint8_t av_unused end_bit = (fu_header & 0x40) >> 6;
274 uint8_t nal_type = (fu_header & 0x1f);
275 uint8_t reconstructed_nal;
277 // Reconstruct this packet's true nal; only the data follows.
278 /* The original nal forbidden bit and NRI are stored in this
280 reconstructed_nal = fu_indicator & (0xe0);
281 reconstructed_nal |= nal_type;
283 // skip the fu_header
289 data->packet_types_received[nal_type]++;
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);
298 av_new_packet(pkt, len);
299 memcpy(pkt->data, buf, len);
302 av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H264 RTP packet\n");
303 result = AVERROR_INVALIDDATA;
307 case 30: // undefined
308 case 31: // undefined
310 av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)", type);
311 result = AVERROR_INVALIDDATA;
315 pkt->stream_index = st->index;
320 static PayloadContext *h264_new_context(void)
322 return av_mallocz(sizeof(PayloadContext) + FF_INPUT_BUFFER_PADDING_SIZE);
325 static void h264_free_context(PayloadContext *data)
330 for (ii = 0; ii < 32; ii++) {
331 if (data->packet_types_received[ii])
332 av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
333 data->packet_types_received[ii], ii);
340 static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
341 PayloadContext *h264_data, const char *line)
344 AVCodecContext *codec;
345 const char *p = line;
350 stream = s->streams[st_index];
351 codec = stream->codec;
353 if (av_strstart(p, "framesize:", &p)) {
357 // remove the protocol identifier
358 while (*p && *p == ' ') p++; // strip spaces.
359 while (*p && *p != ' ') p++; // eat protocol identifier
360 while (*p && *p == ' ') p++; // strip trailing spaces.
361 while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1) {
366 // a='framesize:96 320-240'
367 // set our parameters
368 codec->width = atoi(buf1);
369 codec->height = atoi(p + 1); // skip the -
370 codec->pix_fmt = PIX_FMT_YUV420P;
371 } else if (av_strstart(p, "fmtp:", &p)) {
372 return ff_parse_fmtp(stream, h264_data, p, sdp_parse_fmtp_config_h264);
373 } else if (av_strstart(p, "cliprect:", &p)) {
374 // could use this if we wanted.
380 RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
382 .codec_type = AVMEDIA_TYPE_VIDEO,
383 .codec_id = CODEC_ID_H264,
384 .parse_sdp_a_line = parse_h264_sdp_line,
385 .alloc = h264_new_context,
386 .free = h264_free_context,
387 .parse_packet = h264_handle_packet