Imported Debian version 2.5.2~trusty
[deb_ffmpeg.git] / ffmpeg / libavformat / rtmppkt.c
... / ...
CommitLineData
1/*
2 * RTMP input format
3 * Copyright (c) 2009 Konstantin Shishkov
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 "libavcodec/bytestream.h"
23#include "libavutil/avstring.h"
24#include "libavutil/intfloat.h"
25#include "avformat.h"
26
27#include "rtmppkt.h"
28#include "flv.h"
29#include "url.h"
30
31void ff_amf_write_bool(uint8_t **dst, int val)
32{
33 bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
34 bytestream_put_byte(dst, val);
35}
36
37void ff_amf_write_number(uint8_t **dst, double val)
38{
39 bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
40 bytestream_put_be64(dst, av_double2int(val));
41}
42
43void ff_amf_write_string(uint8_t **dst, const char *str)
44{
45 bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
46 bytestream_put_be16(dst, strlen(str));
47 bytestream_put_buffer(dst, str, strlen(str));
48}
49
50void ff_amf_write_string2(uint8_t **dst, const char *str1, const char *str2)
51{
52 int len1 = 0, len2 = 0;
53 if (str1)
54 len1 = strlen(str1);
55 if (str2)
56 len2 = strlen(str2);
57 bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
58 bytestream_put_be16(dst, len1 + len2);
59 bytestream_put_buffer(dst, str1, len1);
60 bytestream_put_buffer(dst, str2, len2);
61}
62
63void ff_amf_write_null(uint8_t **dst)
64{
65 bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
66}
67
68void ff_amf_write_object_start(uint8_t **dst)
69{
70 bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
71}
72
73void ff_amf_write_field_name(uint8_t **dst, const char *str)
74{
75 bytestream_put_be16(dst, strlen(str));
76 bytestream_put_buffer(dst, str, strlen(str));
77}
78
79void ff_amf_write_object_end(uint8_t **dst)
80{
81 /* first two bytes are field name length = 0,
82 * AMF object should end with it and end marker
83 */
84 bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
85}
86
87int ff_amf_read_bool(GetByteContext *bc, int *val)
88{
89 if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_BOOL)
90 return AVERROR_INVALIDDATA;
91 *val = bytestream2_get_byte(bc);
92 return 0;
93}
94
95int ff_amf_read_number(GetByteContext *bc, double *val)
96{
97 uint64_t read;
98 if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NUMBER)
99 return AVERROR_INVALIDDATA;
100 read = bytestream2_get_be64(bc);
101 *val = av_int2double(read);
102 return 0;
103}
104
105int ff_amf_get_string(GetByteContext *bc, uint8_t *str,
106 int strsize, int *length)
107{
108 int stringlen = 0;
109 int readsize;
110 stringlen = bytestream2_get_be16(bc);
111 if (stringlen + 1 > strsize)
112 return AVERROR(EINVAL);
113 readsize = bytestream2_get_buffer(bc, str, stringlen);
114 if (readsize != stringlen) {
115 av_log(NULL, AV_LOG_WARNING,
116 "Unable to read as many bytes as AMF string signaled\n");
117 }
118 str[readsize] = '\0';
119 *length = FFMIN(stringlen, readsize);
120 return 0;
121}
122
123int ff_amf_read_string(GetByteContext *bc, uint8_t *str,
124 int strsize, int *length)
125{
126 if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_STRING)
127 return AVERROR_INVALIDDATA;
128 return ff_amf_get_string(bc, str, strsize, length);
129}
130
131int ff_amf_read_null(GetByteContext *bc)
132{
133 if (bytestream2_get_byte(bc) != AMF_DATA_TYPE_NULL)
134 return AVERROR_INVALIDDATA;
135 return 0;
136}
137
138int ff_rtmp_check_alloc_array(RTMPPacket **prev_pkt, int *nb_prev_pkt,
139 int channel)
140{
141 int nb_alloc;
142 RTMPPacket *ptr;
143 if (channel < *nb_prev_pkt)
144 return 0;
145
146 nb_alloc = channel + 16;
147 // This can't use the av_reallocp family of functions, since we
148 // would need to free each element in the array before the array
149 // itself is freed.
150 ptr = av_realloc_array(*prev_pkt, nb_alloc, sizeof(**prev_pkt));
151 if (!ptr)
152 return AVERROR(ENOMEM);
153 memset(ptr + *nb_prev_pkt, 0, (nb_alloc - *nb_prev_pkt) * sizeof(*ptr));
154 *prev_pkt = ptr;
155 *nb_prev_pkt = nb_alloc;
156 return 0;
157}
158
159int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
160 int chunk_size, RTMPPacket **prev_pkt, int *nb_prev_pkt)
161{
162 uint8_t hdr;
163
164 if (ffurl_read(h, &hdr, 1) != 1)
165 return AVERROR(EIO);
166
167 return ff_rtmp_packet_read_internal(h, p, chunk_size, prev_pkt,
168 nb_prev_pkt, hdr);
169}
170
171static int rtmp_packet_read_one_chunk(URLContext *h, RTMPPacket *p,
172 int chunk_size, RTMPPacket **prev_pkt_ptr,
173 int *nb_prev_pkt, uint8_t hdr)
174{
175
176 uint8_t buf[16];
177 int channel_id, timestamp, size;
178 uint32_t ts_field; // non-extended timestamp or delta field
179 uint32_t extra = 0;
180 enum RTMPPacketType type;
181 int written = 0;
182 int ret, toread;
183 RTMPPacket *prev_pkt;
184
185 written++;
186 channel_id = hdr & 0x3F;
187
188 if (channel_id < 2) { //special case for channel number >= 64
189 buf[1] = 0;
190 if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)
191 return AVERROR(EIO);
192 written += channel_id + 1;
193 channel_id = AV_RL16(buf) + 64;
194 }
195 if ((ret = ff_rtmp_check_alloc_array(prev_pkt_ptr, nb_prev_pkt,
196 channel_id)) < 0)
197 return ret;
198 prev_pkt = *prev_pkt_ptr;
199 size = prev_pkt[channel_id].size;
200 type = prev_pkt[channel_id].type;
201 extra = prev_pkt[channel_id].extra;
202
203 hdr >>= 6; // header size indicator
204 if (hdr == RTMP_PS_ONEBYTE) {
205 ts_field = prev_pkt[channel_id].ts_field;
206 } else {
207 if (ffurl_read_complete(h, buf, 3) != 3)
208 return AVERROR(EIO);
209 written += 3;
210 ts_field = AV_RB24(buf);
211 if (hdr != RTMP_PS_FOURBYTES) {
212 if (ffurl_read_complete(h, buf, 3) != 3)
213 return AVERROR(EIO);
214 written += 3;
215 size = AV_RB24(buf);
216 if (ffurl_read_complete(h, buf, 1) != 1)
217 return AVERROR(EIO);
218 written++;
219 type = buf[0];
220 if (hdr == RTMP_PS_TWELVEBYTES) {
221 if (ffurl_read_complete(h, buf, 4) != 4)
222 return AVERROR(EIO);
223 written += 4;
224 extra = AV_RL32(buf);
225 }
226 }
227 }
228 if (ts_field == 0xFFFFFF) {
229 if (ffurl_read_complete(h, buf, 4) != 4)
230 return AVERROR(EIO);
231 timestamp = AV_RB32(buf);
232 } else {
233 timestamp = ts_field;
234 }
235 if (hdr != RTMP_PS_TWELVEBYTES)
236 timestamp += prev_pkt[channel_id].timestamp;
237
238 if (!prev_pkt[channel_id].read) {
239 if ((ret = ff_rtmp_packet_create(p, channel_id, type, timestamp,
240 size)) < 0)
241 return ret;
242 p->read = written;
243 p->offset = 0;
244 prev_pkt[channel_id].ts_field = ts_field;
245 prev_pkt[channel_id].timestamp = timestamp;
246 } else {
247 // previous packet in this channel hasn't completed reading
248 RTMPPacket *prev = &prev_pkt[channel_id];
249 p->data = prev->data;
250 p->size = prev->size;
251 p->channel_id = prev->channel_id;
252 p->type = prev->type;
253 p->ts_field = prev->ts_field;
254 p->extra = prev->extra;
255 p->offset = prev->offset;
256 p->read = prev->read + written;
257 p->timestamp = prev->timestamp;
258 prev->data = NULL;
259 }
260 p->extra = extra;
261 // save history
262 prev_pkt[channel_id].channel_id = channel_id;
263 prev_pkt[channel_id].type = type;
264 prev_pkt[channel_id].size = size;
265 prev_pkt[channel_id].extra = extra;
266 size = size - p->offset;
267
268 toread = FFMIN(size, chunk_size);
269 if (ffurl_read_complete(h, p->data + p->offset, toread) != toread) {
270 ff_rtmp_packet_destroy(p);
271 return AVERROR(EIO);
272 }
273 size -= toread;
274 p->read += toread;
275 p->offset += toread;
276
277 if (size > 0) {
278 RTMPPacket *prev = &prev_pkt[channel_id];
279 prev->data = p->data;
280 prev->read = p->read;
281 prev->offset = p->offset;
282 p->data = NULL;
283 return AVERROR(EAGAIN);
284 }
285
286 prev_pkt[channel_id].read = 0; // read complete; reset if needed
287 return p->read;
288}
289
290int ff_rtmp_packet_read_internal(URLContext *h, RTMPPacket *p, int chunk_size,
291 RTMPPacket **prev_pkt, int *nb_prev_pkt,
292 uint8_t hdr)
293{
294 while (1) {
295 int ret = rtmp_packet_read_one_chunk(h, p, chunk_size, prev_pkt,
296 nb_prev_pkt, hdr);
297 if (ret > 0 || ret != AVERROR(EAGAIN))
298 return ret;
299
300 if (ffurl_read(h, &hdr, 1) != 1)
301 return AVERROR(EIO);
302 }
303}
304
305int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
306 int chunk_size, RTMPPacket **prev_pkt_ptr,
307 int *nb_prev_pkt)
308{
309 uint8_t pkt_hdr[16], *p = pkt_hdr;
310 int mode = RTMP_PS_TWELVEBYTES;
311 int off = 0;
312 int written = 0;
313 int ret;
314 RTMPPacket *prev_pkt;
315 int use_delta; // flag if using timestamp delta, not RTMP_PS_TWELVEBYTES
316 uint32_t timestamp; // full 32-bit timestamp or delta value
317
318 if ((ret = ff_rtmp_check_alloc_array(prev_pkt_ptr, nb_prev_pkt,
319 pkt->channel_id)) < 0)
320 return ret;
321 prev_pkt = *prev_pkt_ptr;
322
323 //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
324 use_delta = prev_pkt[pkt->channel_id].channel_id &&
325 pkt->extra == prev_pkt[pkt->channel_id].extra &&
326 pkt->timestamp >= prev_pkt[pkt->channel_id].timestamp;
327
328 timestamp = pkt->timestamp;
329 if (use_delta) {
330 timestamp -= prev_pkt[pkt->channel_id].timestamp;
331 }
332 if (timestamp >= 0xFFFFFF) {
333 pkt->ts_field = 0xFFFFFF;
334 } else {
335 pkt->ts_field = timestamp;
336 }
337
338 if (use_delta) {
339 if (pkt->type == prev_pkt[pkt->channel_id].type &&
340 pkt->size == prev_pkt[pkt->channel_id].size) {
341 mode = RTMP_PS_FOURBYTES;
342 if (pkt->ts_field == prev_pkt[pkt->channel_id].ts_field)
343 mode = RTMP_PS_ONEBYTE;
344 } else {
345 mode = RTMP_PS_EIGHTBYTES;
346 }
347 }
348
349 if (pkt->channel_id < 64) {
350 bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
351 } else if (pkt->channel_id < 64 + 256) {
352 bytestream_put_byte(&p, 0 | (mode << 6));
353 bytestream_put_byte(&p, pkt->channel_id - 64);
354 } else {
355 bytestream_put_byte(&p, 1 | (mode << 6));
356 bytestream_put_le16(&p, pkt->channel_id - 64);
357 }
358 if (mode != RTMP_PS_ONEBYTE) {
359 bytestream_put_be24(&p, pkt->ts_field);
360 if (mode != RTMP_PS_FOURBYTES) {
361 bytestream_put_be24(&p, pkt->size);
362 bytestream_put_byte(&p, pkt->type);
363 if (mode == RTMP_PS_TWELVEBYTES)
364 bytestream_put_le32(&p, pkt->extra);
365 }
366 }
367 if (pkt->ts_field == 0xFFFFFF)
368 bytestream_put_be32(&p, timestamp);
369 // save history
370 prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
371 prev_pkt[pkt->channel_id].type = pkt->type;
372 prev_pkt[pkt->channel_id].size = pkt->size;
373 prev_pkt[pkt->channel_id].timestamp = pkt->timestamp;
374 prev_pkt[pkt->channel_id].ts_field = pkt->ts_field;
375 prev_pkt[pkt->channel_id].extra = pkt->extra;
376
377 if ((ret = ffurl_write(h, pkt_hdr, p - pkt_hdr)) < 0)
378 return ret;
379 written = p - pkt_hdr + pkt->size;
380 while (off < pkt->size) {
381 int towrite = FFMIN(chunk_size, pkt->size - off);
382 if ((ret = ffurl_write(h, pkt->data + off, towrite)) < 0)
383 return ret;
384 off += towrite;
385 if (off < pkt->size) {
386 uint8_t marker = 0xC0 | pkt->channel_id;
387 if ((ret = ffurl_write(h, &marker, 1)) < 0)
388 return ret;
389 written++;
390 }
391 }
392 return written;
393}
394
395int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
396 int timestamp, int size)
397{
398 if (size) {
399 pkt->data = av_realloc(NULL, size);
400 if (!pkt->data)
401 return AVERROR(ENOMEM);
402 }
403 pkt->size = size;
404 pkt->channel_id = channel_id;
405 pkt->type = type;
406 pkt->timestamp = timestamp;
407 pkt->extra = 0;
408 pkt->ts_field = 0;
409
410 return 0;
411}
412
413void ff_rtmp_packet_destroy(RTMPPacket *pkt)
414{
415 if (!pkt)
416 return;
417 av_freep(&pkt->data);
418 pkt->size = 0;
419}
420
421int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
422{
423 const uint8_t *base = data;
424 AMFDataType type;
425 unsigned nb = -1;
426 int parse_key = 1;
427
428 if (data >= data_end)
429 return -1;
430 switch ((type = *data++)) {
431 case AMF_DATA_TYPE_NUMBER: return 9;
432 case AMF_DATA_TYPE_BOOL: return 2;
433 case AMF_DATA_TYPE_STRING: return 3 + AV_RB16(data);
434 case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
435 case AMF_DATA_TYPE_NULL: return 1;
436 case AMF_DATA_TYPE_ARRAY:
437 parse_key = 0;
438 case AMF_DATA_TYPE_MIXEDARRAY:
439 nb = bytestream_get_be32(&data);
440 case AMF_DATA_TYPE_OBJECT:
441 while (nb-- > 0 || type != AMF_DATA_TYPE_ARRAY) {
442 int t;
443 if (parse_key) {
444 int size = bytestream_get_be16(&data);
445 if (!size) {
446 data++;
447 break;
448 }
449 if (size < 0 || size >= data_end - data)
450 return -1;
451 data += size;
452 }
453 t = ff_amf_tag_size(data, data_end);
454 if (t < 0 || t >= data_end - data)
455 return -1;
456 data += t;
457 }
458 return data - base;
459 case AMF_DATA_TYPE_OBJECT_END: return 1;
460 default: return -1;
461 }
462}
463
464int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
465 const uint8_t *name, uint8_t *dst, int dst_size)
466{
467 int namelen = strlen(name);
468 int len;
469
470 while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
471 len = ff_amf_tag_size(data, data_end);
472 if (len < 0)
473 len = data_end - data;
474 data += len;
475 }
476 if (data_end - data < 3)
477 return -1;
478 data++;
479 for (;;) {
480 int size = bytestream_get_be16(&data);
481 if (!size)
482 break;
483 if (size < 0 || size >= data_end - data)
484 return -1;
485 data += size;
486 if (size == namelen && !memcmp(data-size, name, namelen)) {
487 switch (*data++) {
488 case AMF_DATA_TYPE_NUMBER:
489 snprintf(dst, dst_size, "%g", av_int2double(AV_RB64(data)));
490 break;
491 case AMF_DATA_TYPE_BOOL:
492 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
493 break;
494 case AMF_DATA_TYPE_STRING:
495 len = bytestream_get_be16(&data);
496 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
497 break;
498 default:
499 return -1;
500 }
501 return 0;
502 }
503 len = ff_amf_tag_size(data, data_end);
504 if (len < 0 || len >= data_end - data)
505 return -1;
506 data += len;
507 }
508 return -1;
509}
510
511static const char* rtmp_packet_type(int type)
512{
513 switch (type) {
514 case RTMP_PT_CHUNK_SIZE: return "chunk size";
515 case RTMP_PT_BYTES_READ: return "bytes read";
516 case RTMP_PT_PING: return "ping";
517 case RTMP_PT_SERVER_BW: return "server bandwidth";
518 case RTMP_PT_CLIENT_BW: return "client bandwidth";
519 case RTMP_PT_AUDIO: return "audio packet";
520 case RTMP_PT_VIDEO: return "video packet";
521 case RTMP_PT_FLEX_STREAM: return "Flex shared stream";
522 case RTMP_PT_FLEX_OBJECT: return "Flex shared object";
523 case RTMP_PT_FLEX_MESSAGE: return "Flex shared message";
524 case RTMP_PT_NOTIFY: return "notification";
525 case RTMP_PT_SHARED_OBJ: return "shared object";
526 case RTMP_PT_INVOKE: return "invoke";
527 case RTMP_PT_METADATA: return "metadata";
528 default: return "unknown";
529 }
530}
531
532static void amf_tag_contents(void *ctx, const uint8_t *data,
533 const uint8_t *data_end)
534{
535 unsigned int size, nb = -1;
536 char buf[1024];
537 AMFDataType type;
538 int parse_key = 1;
539
540 if (data >= data_end)
541 return;
542 switch ((type = *data++)) {
543 case AMF_DATA_TYPE_NUMBER:
544 av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2double(AV_RB64(data)));
545 return;
546 case AMF_DATA_TYPE_BOOL:
547 av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
548 return;
549 case AMF_DATA_TYPE_STRING:
550 case AMF_DATA_TYPE_LONG_STRING:
551 if (type == AMF_DATA_TYPE_STRING) {
552 size = bytestream_get_be16(&data);
553 } else {
554 size = bytestream_get_be32(&data);
555 }
556 size = FFMIN(size, sizeof(buf) - 1);
557 memcpy(buf, data, size);
558 buf[size] = 0;
559 av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
560 return;
561 case AMF_DATA_TYPE_NULL:
562 av_log(ctx, AV_LOG_DEBUG, " NULL\n");
563 return;
564 case AMF_DATA_TYPE_ARRAY:
565 parse_key = 0;
566 case AMF_DATA_TYPE_MIXEDARRAY:
567 nb = bytestream_get_be32(&data);
568 case AMF_DATA_TYPE_OBJECT:
569 av_log(ctx, AV_LOG_DEBUG, " {\n");
570 while (nb-- > 0 || type != AMF_DATA_TYPE_ARRAY) {
571 int t;
572 if (parse_key) {
573 size = bytestream_get_be16(&data);
574 size = FFMIN(size, sizeof(buf) - 1);
575 if (!size) {
576 av_log(ctx, AV_LOG_DEBUG, " }\n");
577 data++;
578 break;
579 }
580 memcpy(buf, data, size);
581 buf[size] = 0;
582 if (size >= data_end - data)
583 return;
584 data += size;
585 av_log(ctx, AV_LOG_DEBUG, " %s: ", buf);
586 }
587 amf_tag_contents(ctx, data, data_end);
588 t = ff_amf_tag_size(data, data_end);
589 if (t < 0 || t >= data_end - data)
590 return;
591 data += t;
592 }
593 return;
594 case AMF_DATA_TYPE_OBJECT_END:
595 av_log(ctx, AV_LOG_DEBUG, " }\n");
596 return;
597 default:
598 return;
599 }
600}
601
602void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
603{
604 av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
605 rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->size);
606 if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
607 uint8_t *src = p->data, *src_end = p->data + p->size;
608 while (src < src_end) {
609 int sz;
610 amf_tag_contents(ctx, src, src_end);
611 sz = ff_amf_tag_size(src, src_end);
612 if (sz < 0)
613 break;
614 src += sz;
615 }
616 } else if (p->type == RTMP_PT_SERVER_BW){
617 av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
618 } else if (p->type == RTMP_PT_CLIENT_BW){
619 av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
620 } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
621 int i;
622 for (i = 0; i < p->size; i++)
623 av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
624 av_log(ctx, AV_LOG_DEBUG, "\n");
625 }
626}
627
628int ff_amf_match_string(const uint8_t *data, int size, const char *str)
629{
630 int len = strlen(str);
631 int amf_len, type;
632
633 if (size < 1)
634 return 0;
635
636 type = *data++;
637
638 if (type != AMF_DATA_TYPE_LONG_STRING &&
639 type != AMF_DATA_TYPE_STRING)
640 return 0;
641
642 if (type == AMF_DATA_TYPE_LONG_STRING) {
643 if ((size -= 4 + 1) < 0)
644 return 0;
645 amf_len = bytestream_get_be32(&data);
646 } else {
647 if ((size -= 2 + 1) < 0)
648 return 0;
649 amf_len = bytestream_get_be16(&data);
650 }
651
652 if (amf_len > size)
653 return 0;
654
655 if (amf_len != len)
656 return 0;
657
658 return !memcmp(data, str, len);
659}