abf1f39279690b0d7e1f376c5af3ae3287c9686c
[libav.git] / libavformat / rtpdec_h264.c
1 /*
2 * RTP H264 Protocol (RFC3984)
3 * Copyright (c) 2006 Ryan Martell
4 *
5 * This file is part of Libav.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
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,
33 * FU-B packet types)
34 */
35
36 #include "libavutil/attributes.h"
37 #include "libavutil/base64.h"
38 #include "libavutil/avstring.h"
39 #include "libavcodec/get_bits.h"
40 #include "avformat.h"
41
42 #include "network.h"
43 #include <assert.h>
44
45 #include "rtpdec.h"
46 #include "rtpdec_formats.h"
47
48 struct PayloadContext {
49 // sdp setup parameters
50 uint8_t profile_idc;
51 uint8_t profile_iop;
52 uint8_t level_idc;
53 int packetization_mode;
54 #ifdef DEBUG
55 int packet_types_received[32];
56 #endif
57 };
58
59 #ifdef DEBUG
60 #define COUNT_NAL_TYPE(data, nal) data->packet_types_received[(nal) & 0x1f]++
61 #else
62 #define COUNT_NAL_TYPE(data, nal) do { } while (0)
63 #endif
64
65 static const uint8_t start_sequence[] = { 0, 0, 0, 1 };
66
67 static int sdp_parse_fmtp_config_h264(AVFormatContext *s,
68 AVStream *stream,
69 PayloadContext *h264_data,
70 char *attr, char *value)
71 {
72 AVCodecContext *codec = stream->codec;
73 assert(codec->codec_id == AV_CODEC_ID_H264);
74 assert(h264_data != NULL);
75
76 if (!strcmp(attr, "packetization-mode")) {
77 av_log(s, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value));
78 h264_data->packetization_mode = atoi(value);
79 /*
80 * Packetization Mode:
81 * 0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
82 * 1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
83 * 2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A),
84 * and 29 (FU-B) are allowed.
85 */
86 if (h264_data->packetization_mode > 1)
87 av_log(s, AV_LOG_ERROR,
88 "Interleaved RTP mode is not supported yet.\n");
89 } else if (!strcmp(attr, "profile-level-id")) {
90 if (strlen(value) == 6) {
91 char buffer[3];
92 // 6 characters=3 bytes, in hex.
93 uint8_t profile_idc;
94 uint8_t profile_iop;
95 uint8_t level_idc;
96
97 buffer[0] = value[0];
98 buffer[1] = value[1];
99 buffer[2] = '\0';
100 profile_idc = strtol(buffer, NULL, 16);
101 buffer[0] = value[2];
102 buffer[1] = value[3];
103 profile_iop = strtol(buffer, NULL, 16);
104 buffer[0] = value[4];
105 buffer[1] = value[5];
106 level_idc = strtol(buffer, NULL, 16);
107
108 av_log(s, 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 codec->extradata_size = 0;
117 av_freep(&codec->extradata);
118
119 while (*value) {
120 char base64packet[1024];
121 uint8_t decoded_packet[1024];
122 int packet_size;
123 char *dst = base64packet;
124
125 while (*value && *value != ','
126 && (dst - base64packet) < sizeof(base64packet) - 1) {
127 *dst++ = *value++;
128 }
129 *dst++ = '\0';
130
131 if (*value == ',')
132 value++;
133
134 packet_size = av_base64_decode(decoded_packet, base64packet,
135 sizeof(decoded_packet));
136 if (packet_size > 0) {
137 uint8_t *dest = av_malloc(packet_size + sizeof(start_sequence) +
138 codec->extradata_size +
139 FF_INPUT_BUFFER_PADDING_SIZE);
140 if (!dest) {
141 av_log(s, AV_LOG_ERROR,
142 "Unable to allocate memory for extradata!\n");
143 return AVERROR(ENOMEM);
144 }
145 if (codec->extradata_size) {
146 memcpy(dest, codec->extradata, codec->extradata_size);
147 av_free(codec->extradata);
148 }
149
150 memcpy(dest + codec->extradata_size, start_sequence,
151 sizeof(start_sequence));
152 memcpy(dest + codec->extradata_size + sizeof(start_sequence),
153 decoded_packet, packet_size);
154 memset(dest + codec->extradata_size + sizeof(start_sequence) +
155 packet_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
156
157 codec->extradata = dest;
158 codec->extradata_size += sizeof(start_sequence) + packet_size;
159 }
160 }
161 av_log(s, AV_LOG_DEBUG, "Extradata set to %p (size: %d)!\n",
162 codec->extradata, codec->extradata_size);
163 }
164 return 0;
165 }
166
167 // return 0 on packet, no more left, 1 on packet, 1 on partial packet
168 static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
169 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
170 const uint8_t *buf, int len, uint16_t seq,
171 int flags)
172 {
173 uint8_t nal;
174 uint8_t type;
175 int result = 0;
176
177 if (!len) {
178 av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
179 return AVERROR_INVALIDDATA;
180 }
181 nal = buf[0];
182 type = nal & 0x1f;
183
184 assert(data);
185 assert(buf);
186
187 /* Simplify the case (these are all the nal types used internally by
188 * the h264 codec). */
189 if (type >= 1 && type <= 23)
190 type = 1;
191 switch (type) {
192 case 0: // undefined, but pass them through
193 case 1:
194 if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0)
195 return result;
196 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
197 memcpy(pkt->data + sizeof(start_sequence), buf, len);
198 COUNT_NAL_TYPE(data, nal);
199 break;
200
201 case 24: // STAP-A (one packet, multiple nals)
202 // consume the STAP-A NAL
203 buf++;
204 len--;
205 // first we are going to figure out the total size
206 {
207 int pass = 0;
208 int total_length = 0;
209 uint8_t *dst = NULL;
210
211 for (pass = 0; pass < 2; pass++) {
212 const uint8_t *src = buf;
213 int src_len = len;
214
215 while (src_len > 2) {
216 uint16_t nal_size = AV_RB16(src);
217
218 // consume the length of the aggregate
219 src += 2;
220 src_len -= 2;
221
222 if (nal_size <= src_len) {
223 if (pass == 0) {
224 // counting
225 total_length += sizeof(start_sequence) + nal_size;
226 } else {
227 // copying
228 assert(dst);
229 memcpy(dst, start_sequence, sizeof(start_sequence));
230 dst += sizeof(start_sequence);
231 memcpy(dst, src, nal_size);
232 COUNT_NAL_TYPE(data, *src);
233 dst += nal_size;
234 }
235 } else {
236 av_log(ctx, AV_LOG_ERROR,
237 "nal size exceeds length: %d %d\n", nal_size, src_len);
238 }
239
240 // eat what we handled
241 src += nal_size;
242 src_len -= nal_size;
243
244 if (src_len < 0)
245 av_log(ctx, AV_LOG_ERROR,
246 "Consumed more bytes than we got! (%d)\n", src_len);
247 }
248
249 if (pass == 0) {
250 /* now we know the total size of the packet (with the
251 * start sequences added) */
252 if ((result = av_new_packet(pkt, total_length)) < 0)
253 return result;
254 dst = pkt->data;
255 } else {
256 assert(dst - pkt->data == total_length);
257 }
258 }
259 }
260 break;
261
262 case 25: // STAP-B
263 case 26: // MTAP-16
264 case 27: // MTAP-24
265 case 29: // FU-B
266 av_log(ctx, AV_LOG_ERROR,
267 "Unhandled type (%d) (See RFC for implementation details\n",
268 type);
269 result = AVERROR(ENOSYS);
270 break;
271
272 case 28: // FU-A (fragmented nal)
273 buf++;
274 len--; // skip the fu_indicator
275 if (len > 1) {
276 // these are the same as above, we just redo them here for clarity
277 uint8_t fu_indicator = nal;
278 uint8_t fu_header = *buf;
279 uint8_t start_bit = fu_header >> 7;
280 uint8_t av_unused end_bit = (fu_header & 0x40) >> 6;
281 uint8_t nal_type = fu_header & 0x1f;
282 uint8_t reconstructed_nal;
283
284 // Reconstruct this packet's true nal; only the data follows.
285 /* The original nal forbidden bit and NRI are stored in this
286 * packet's nal. */
287 reconstructed_nal = fu_indicator & 0xe0;
288 reconstructed_nal |= nal_type;
289
290 // skip the fu_header
291 buf++;
292 len--;
293
294 if (start_bit)
295 COUNT_NAL_TYPE(data, nal_type);
296 if (start_bit) {
297 /* copy in the start sequence, and the reconstructed nal */
298 if ((result = av_new_packet(pkt, sizeof(start_sequence) + sizeof(nal) + len)) < 0)
299 return result;
300 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
301 pkt->data[sizeof(start_sequence)] = reconstructed_nal;
302 memcpy(pkt->data + sizeof(start_sequence) + sizeof(nal), buf, len);
303 } else {
304 if ((result = av_new_packet(pkt, len)) < 0)
305 return result;
306 memcpy(pkt->data, buf, len);
307 }
308 } else {
309 av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H264 RTP packet\n");
310 result = AVERROR_INVALIDDATA;
311 }
312 break;
313
314 case 30: // undefined
315 case 31: // undefined
316 default:
317 av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)\n", type);
318 result = AVERROR_INVALIDDATA;
319 break;
320 }
321
322 pkt->stream_index = st->index;
323
324 return result;
325 }
326
327 static PayloadContext *h264_new_context(void)
328 {
329 return av_mallocz(sizeof(PayloadContext) + FF_INPUT_BUFFER_PADDING_SIZE);
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 av_free(data);
345 }
346
347 static av_cold int h264_init(AVFormatContext *s, int st_index,
348 PayloadContext *data)
349 {
350 if (st_index < 0)
351 return 0;
352 s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
353 return 0;
354 }
355
356 static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
357 PayloadContext *h264_data, const char *line)
358 {
359 AVStream *stream;
360 AVCodecContext *codec;
361 const char *p = line;
362
363 if (st_index < 0)
364 return 0;
365
366 stream = s->streams[st_index];
367 codec = stream->codec;
368
369 if (av_strstart(p, "framesize:", &p)) {
370 char buf1[50];
371 char *dst = buf1;
372
373 // remove the protocol identifier
374 while (*p && *p == ' ')
375 p++; // strip spaces.
376 while (*p && *p != ' ')
377 p++; // eat protocol identifier
378 while (*p && *p == ' ')
379 p++; // strip trailing spaces.
380 while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1)
381 *dst++ = *p++;
382 *dst = '\0';
383
384 // a='framesize:96 320-240'
385 // set our parameters
386 codec->width = atoi(buf1);
387 codec->height = atoi(p + 1); // skip the -
388 } else if (av_strstart(p, "fmtp:", &p)) {
389 return ff_parse_fmtp(s, stream, h264_data, p, sdp_parse_fmtp_config_h264);
390 } else if (av_strstart(p, "cliprect:", &p)) {
391 // could use this if we wanted.
392 }
393
394 return 0;
395 }
396
397 RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
398 .enc_name = "H264",
399 .codec_type = AVMEDIA_TYPE_VIDEO,
400 .codec_id = AV_CODEC_ID_H264,
401 .init = h264_init,
402 .parse_sdp_a_line = parse_h264_sdp_line,
403 .alloc = h264_new_context,
404 .free = h264_free_context,
405 .parse_packet = h264_handle_packet
406 };