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  1. /*
  2. * Buffered I/O for ffmpeg system
  3. * Copyright (c) 2000,2001 Fabrice Bellard
  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. #include "libavutil/crc.h"
  22. #include "libavutil/intreadwrite.h"
  23. #include "avformat.h"
  24. #include "avio.h"
  25. #include <stdarg.h>
  26. #define IO_BUFFER_SIZE 32768
  27. static void fill_buffer(ByteIOContext *s);
  28. int init_put_byte(ByteIOContext *s,
  29. unsigned char *buffer,
  30. int buffer_size,
  31. int write_flag,
  32. void *opaque,
  33. int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
  34. int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
  35. int64_t (*seek)(void *opaque, int64_t offset, int whence))
  36. {
  37. s->buffer = buffer;
  38. s->buffer_size = buffer_size;
  39. s->buf_ptr = buffer;
  40. s->opaque = opaque;
  41. url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
  42. s->write_packet = write_packet;
  43. s->read_packet = read_packet;
  44. s->seek = seek;
  45. s->pos = 0;
  46. s->must_flush = 0;
  47. s->eof_reached = 0;
  48. s->error = 0;
  49. s->is_streamed = 0;
  50. s->max_packet_size = 0;
  51. s->update_checksum= NULL;
  52. if(!read_packet && !write_flag){
  53. s->pos = buffer_size;
  54. s->buf_end = s->buffer + buffer_size;
  55. }
  56. s->read_pause = NULL;
  57. s->read_seek = NULL;
  58. return 0;
  59. }
  60. ByteIOContext *av_alloc_put_byte(
  61. unsigned char *buffer,
  62. int buffer_size,
  63. int write_flag,
  64. void *opaque,
  65. int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
  66. int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
  67. int64_t (*seek)(void *opaque, int64_t offset, int whence))
  68. {
  69. ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
  70. init_put_byte(s, buffer, buffer_size, write_flag, opaque,
  71. read_packet, write_packet, seek);
  72. return s;
  73. }
  74. static void flush_buffer(ByteIOContext *s)
  75. {
  76. if (s->buf_ptr > s->buffer) {
  77. if (s->write_packet && !s->error){
  78. int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
  79. if(ret < 0){
  80. s->error = ret;
  81. }
  82. }
  83. if(s->update_checksum){
  84. s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
  85. s->checksum_ptr= s->buffer;
  86. }
  87. s->pos += s->buf_ptr - s->buffer;
  88. }
  89. s->buf_ptr = s->buffer;
  90. }
  91. void put_byte(ByteIOContext *s, int b)
  92. {
  93. *(s->buf_ptr)++ = b;
  94. if (s->buf_ptr >= s->buf_end)
  95. flush_buffer(s);
  96. }
  97. void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
  98. {
  99. while (size > 0) {
  100. int len = FFMIN(s->buf_end - s->buf_ptr, size);
  101. memcpy(s->buf_ptr, buf, len);
  102. s->buf_ptr += len;
  103. if (s->buf_ptr >= s->buf_end)
  104. flush_buffer(s);
  105. buf += len;
  106. size -= len;
  107. }
  108. }
  109. void put_flush_packet(ByteIOContext *s)
  110. {
  111. flush_buffer(s);
  112. s->must_flush = 0;
  113. }
  114. int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
  115. {
  116. int64_t offset1;
  117. int64_t pos;
  118. if(!s)
  119. return AVERROR(EINVAL);
  120. pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
  121. if (whence != SEEK_CUR && whence != SEEK_SET)
  122. return AVERROR(EINVAL);
  123. if (whence == SEEK_CUR) {
  124. offset1 = pos + (s->buf_ptr - s->buffer);
  125. if (offset == 0)
  126. return offset1;
  127. offset += offset1;
  128. }
  129. offset1 = offset - pos;
  130. if (!s->must_flush &&
  131. offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
  132. /* can do the seek inside the buffer */
  133. s->buf_ptr = s->buffer + offset1;
  134. } else if(s->is_streamed && !s->write_flag &&
  135. offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
  136. while(s->pos < offset && !s->eof_reached)
  137. fill_buffer(s);
  138. if (s->eof_reached)
  139. return AVERROR(EPIPE);
  140. s->buf_ptr = s->buf_end + offset - s->pos;
  141. } else {
  142. int64_t res = AVERROR(EPIPE);
  143. #if CONFIG_MUXERS || CONFIG_NETWORK
  144. if (s->write_flag) {
  145. flush_buffer(s);
  146. s->must_flush = 1;
  147. }
  148. #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
  149. if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
  150. return res;
  151. if (!s->write_flag)
  152. s->buf_end = s->buffer;
  153. s->buf_ptr = s->buffer;
  154. s->pos = offset;
  155. }
  156. s->eof_reached = 0;
  157. return offset;
  158. }
  159. void url_fskip(ByteIOContext *s, int64_t offset)
  160. {
  161. url_fseek(s, offset, SEEK_CUR);
  162. }
  163. int64_t url_ftell(ByteIOContext *s)
  164. {
  165. return url_fseek(s, 0, SEEK_CUR);
  166. }
  167. int64_t url_fsize(ByteIOContext *s)
  168. {
  169. int64_t size;
  170. if(!s)
  171. return AVERROR(EINVAL);
  172. if (!s->seek)
  173. return AVERROR(EPIPE);
  174. size = s->seek(s->opaque, 0, AVSEEK_SIZE);
  175. if(size<0){
  176. if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
  177. return size;
  178. size++;
  179. s->seek(s->opaque, s->pos, SEEK_SET);
  180. }
  181. return size;
  182. }
  183. int url_feof(ByteIOContext *s)
  184. {
  185. if(!s)
  186. return 0;
  187. return s->eof_reached;
  188. }
  189. int url_ferror(ByteIOContext *s)
  190. {
  191. if(!s)
  192. return 0;
  193. return s->error;
  194. }
  195. void put_le32(ByteIOContext *s, unsigned int val)
  196. {
  197. put_byte(s, val);
  198. put_byte(s, val >> 8);
  199. put_byte(s, val >> 16);
  200. put_byte(s, val >> 24);
  201. }
  202. void put_be32(ByteIOContext *s, unsigned int val)
  203. {
  204. put_byte(s, val >> 24);
  205. put_byte(s, val >> 16);
  206. put_byte(s, val >> 8);
  207. put_byte(s, val);
  208. }
  209. void put_strz(ByteIOContext *s, const char *str)
  210. {
  211. if (str)
  212. put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
  213. else
  214. put_byte(s, 0);
  215. }
  216. void put_le64(ByteIOContext *s, uint64_t val)
  217. {
  218. put_le32(s, (uint32_t)(val & 0xffffffff));
  219. put_le32(s, (uint32_t)(val >> 32));
  220. }
  221. void put_be64(ByteIOContext *s, uint64_t val)
  222. {
  223. put_be32(s, (uint32_t)(val >> 32));
  224. put_be32(s, (uint32_t)(val & 0xffffffff));
  225. }
  226. void put_le16(ByteIOContext *s, unsigned int val)
  227. {
  228. put_byte(s, val);
  229. put_byte(s, val >> 8);
  230. }
  231. void put_be16(ByteIOContext *s, unsigned int val)
  232. {
  233. put_byte(s, val >> 8);
  234. put_byte(s, val);
  235. }
  236. void put_le24(ByteIOContext *s, unsigned int val)
  237. {
  238. put_le16(s, val & 0xffff);
  239. put_byte(s, val >> 16);
  240. }
  241. void put_be24(ByteIOContext *s, unsigned int val)
  242. {
  243. put_be16(s, val >> 8);
  244. put_byte(s, val);
  245. }
  246. void put_tag(ByteIOContext *s, const char *tag)
  247. {
  248. while (*tag) {
  249. put_byte(s, *tag++);
  250. }
  251. }
  252. /* Input stream */
  253. static void fill_buffer(ByteIOContext *s)
  254. {
  255. uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
  256. int len= s->buffer_size - (dst - s->buffer);
  257. assert(s->buf_ptr == s->buf_end);
  258. /* no need to do anything if EOF already reached */
  259. if (s->eof_reached)
  260. return;
  261. if(s->update_checksum && dst == s->buffer){
  262. if(s->buf_end > s->checksum_ptr)
  263. s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
  264. s->checksum_ptr= s->buffer;
  265. }
  266. if(s->read_packet)
  267. len = s->read_packet(s->opaque, dst, len);
  268. else
  269. len = 0;
  270. if (len <= 0) {
  271. /* do not modify buffer if EOF reached so that a seek back can
  272. be done without rereading data */
  273. s->eof_reached = 1;
  274. if(len<0)
  275. s->error= len;
  276. } else {
  277. s->pos += len;
  278. s->buf_ptr = dst;
  279. s->buf_end = dst + len;
  280. }
  281. }
  282. unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
  283. unsigned int len)
  284. {
  285. return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
  286. }
  287. unsigned long get_checksum(ByteIOContext *s)
  288. {
  289. s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
  290. s->update_checksum= NULL;
  291. return s->checksum;
  292. }
  293. void init_checksum(ByteIOContext *s,
  294. unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
  295. unsigned long checksum)
  296. {
  297. s->update_checksum= update_checksum;
  298. if(s->update_checksum){
  299. s->checksum= checksum;
  300. s->checksum_ptr= s->buf_ptr;
  301. }
  302. }
  303. /* XXX: put an inline version */
  304. int get_byte(ByteIOContext *s)
  305. {
  306. if (s->buf_ptr < s->buf_end) {
  307. return *s->buf_ptr++;
  308. } else {
  309. fill_buffer(s);
  310. if (s->buf_ptr < s->buf_end)
  311. return *s->buf_ptr++;
  312. else
  313. return 0;
  314. }
  315. }
  316. int url_fgetc(ByteIOContext *s)
  317. {
  318. if (s->buf_ptr < s->buf_end) {
  319. return *s->buf_ptr++;
  320. } else {
  321. fill_buffer(s);
  322. if (s->buf_ptr < s->buf_end)
  323. return *s->buf_ptr++;
  324. else
  325. return URL_EOF;
  326. }
  327. }
  328. int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
  329. {
  330. int len, size1;
  331. size1 = size;
  332. while (size > 0) {
  333. len = s->buf_end - s->buf_ptr;
  334. if (len > size)
  335. len = size;
  336. if (len == 0) {
  337. if(size > s->buffer_size && !s->update_checksum){
  338. if(s->read_packet)
  339. len = s->read_packet(s->opaque, buf, size);
  340. if (len <= 0) {
  341. /* do not modify buffer if EOF reached so that a seek back can
  342. be done without rereading data */
  343. s->eof_reached = 1;
  344. if(len<0)
  345. s->error= len;
  346. break;
  347. } else {
  348. s->pos += len;
  349. size -= len;
  350. buf += len;
  351. s->buf_ptr = s->buffer;
  352. s->buf_end = s->buffer/* + len*/;
  353. }
  354. }else{
  355. fill_buffer(s);
  356. len = s->buf_end - s->buf_ptr;
  357. if (len == 0)
  358. break;
  359. }
  360. } else {
  361. memcpy(buf, s->buf_ptr, len);
  362. buf += len;
  363. s->buf_ptr += len;
  364. size -= len;
  365. }
  366. }
  367. if (size1 == size) {
  368. if (url_ferror(s)) return url_ferror(s);
  369. if (url_feof(s)) return AVERROR_EOF;
  370. }
  371. return size1 - size;
  372. }
  373. int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
  374. {
  375. int len;
  376. if(size<0)
  377. return -1;
  378. len = s->buf_end - s->buf_ptr;
  379. if (len == 0) {
  380. fill_buffer(s);
  381. len = s->buf_end - s->buf_ptr;
  382. }
  383. if (len > size)
  384. len = size;
  385. memcpy(buf, s->buf_ptr, len);
  386. s->buf_ptr += len;
  387. if (!len) {
  388. if (url_ferror(s)) return url_ferror(s);
  389. if (url_feof(s)) return AVERROR_EOF;
  390. }
  391. return len;
  392. }
  393. unsigned int get_le16(ByteIOContext *s)
  394. {
  395. unsigned int val;
  396. val = get_byte(s);
  397. val |= get_byte(s) << 8;
  398. return val;
  399. }
  400. unsigned int get_le24(ByteIOContext *s)
  401. {
  402. unsigned int val;
  403. val = get_le16(s);
  404. val |= get_byte(s) << 16;
  405. return val;
  406. }
  407. unsigned int get_le32(ByteIOContext *s)
  408. {
  409. unsigned int val;
  410. val = get_le16(s);
  411. val |= get_le16(s) << 16;
  412. return val;
  413. }
  414. uint64_t get_le64(ByteIOContext *s)
  415. {
  416. uint64_t val;
  417. val = (uint64_t)get_le32(s);
  418. val |= (uint64_t)get_le32(s) << 32;
  419. return val;
  420. }
  421. unsigned int get_be16(ByteIOContext *s)
  422. {
  423. unsigned int val;
  424. val = get_byte(s) << 8;
  425. val |= get_byte(s);
  426. return val;
  427. }
  428. unsigned int get_be24(ByteIOContext *s)
  429. {
  430. unsigned int val;
  431. val = get_be16(s) << 8;
  432. val |= get_byte(s);
  433. return val;
  434. }
  435. unsigned int get_be32(ByteIOContext *s)
  436. {
  437. unsigned int val;
  438. val = get_be16(s) << 16;
  439. val |= get_be16(s);
  440. return val;
  441. }
  442. char *get_strz(ByteIOContext *s, char *buf, int maxlen)
  443. {
  444. int i = 0;
  445. char c;
  446. while ((c = get_byte(s))) {
  447. if (i < maxlen-1)
  448. buf[i++] = c;
  449. }
  450. buf[i] = 0; /* Ensure null terminated, but may be truncated */
  451. return buf;
  452. }
  453. uint64_t get_be64(ByteIOContext *s)
  454. {
  455. uint64_t val;
  456. val = (uint64_t)get_be32(s) << 32;
  457. val |= (uint64_t)get_be32(s);
  458. return val;
  459. }
  460. uint64_t ff_get_v(ByteIOContext *bc){
  461. uint64_t val = 0;
  462. int tmp;
  463. do{
  464. tmp = get_byte(bc);
  465. val= (val<<7) + (tmp&127);
  466. }while(tmp&128);
  467. return val;
  468. }
  469. int url_fdopen(ByteIOContext **s, URLContext *h)
  470. {
  471. uint8_t *buffer;
  472. int buffer_size, max_packet_size;
  473. max_packet_size = url_get_max_packet_size(h);
  474. if (max_packet_size) {
  475. buffer_size = max_packet_size; /* no need to bufferize more than one packet */
  476. } else {
  477. buffer_size = IO_BUFFER_SIZE;
  478. }
  479. buffer = av_malloc(buffer_size);
  480. if (!buffer)
  481. return AVERROR(ENOMEM);
  482. *s = av_mallocz(sizeof(ByteIOContext));
  483. if(!*s) {
  484. av_free(buffer);
  485. return AVERROR(ENOMEM);
  486. }
  487. if (init_put_byte(*s, buffer, buffer_size,
  488. (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
  489. url_read, url_write, url_seek) < 0) {
  490. av_free(buffer);
  491. av_freep(s);
  492. return AVERROR(EIO);
  493. }
  494. (*s)->is_streamed = h->is_streamed;
  495. (*s)->max_packet_size = max_packet_size;
  496. if(h->prot) {
  497. (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
  498. (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
  499. }
  500. return 0;
  501. }
  502. int url_setbufsize(ByteIOContext *s, int buf_size)
  503. {
  504. uint8_t *buffer;
  505. buffer = av_malloc(buf_size);
  506. if (!buffer)
  507. return AVERROR(ENOMEM);
  508. av_free(s->buffer);
  509. s->buffer = buffer;
  510. s->buffer_size = buf_size;
  511. s->buf_ptr = buffer;
  512. url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
  513. return 0;
  514. }
  515. int url_resetbuf(ByteIOContext *s, int flags)
  516. {
  517. URLContext *h = s->opaque;
  518. if ((flags & URL_RDWR) || (h && h->flags != flags && !h->flags & URL_RDWR))
  519. return AVERROR(EINVAL);
  520. if (flags & URL_WRONLY) {
  521. s->buf_end = s->buffer + s->buffer_size;
  522. s->write_flag = 1;
  523. } else {
  524. s->buf_end = s->buffer;
  525. s->write_flag = 0;
  526. }
  527. return 0;
  528. }
  529. int url_fopen(ByteIOContext **s, const char *filename, int flags)
  530. {
  531. URLContext *h;
  532. int err;
  533. err = url_open(&h, filename, flags);
  534. if (err < 0)
  535. return err;
  536. err = url_fdopen(s, h);
  537. if (err < 0) {
  538. url_close(h);
  539. return err;
  540. }
  541. return 0;
  542. }
  543. int url_fclose(ByteIOContext *s)
  544. {
  545. URLContext *h = s->opaque;
  546. av_free(s->buffer);
  547. av_free(s);
  548. return url_close(h);
  549. }
  550. URLContext *url_fileno(ByteIOContext *s)
  551. {
  552. return s->opaque;
  553. }
  554. #if CONFIG_MUXERS
  555. int url_fprintf(ByteIOContext *s, const char *fmt, ...)
  556. {
  557. va_list ap;
  558. char buf[4096];
  559. int ret;
  560. va_start(ap, fmt);
  561. ret = vsnprintf(buf, sizeof(buf), fmt, ap);
  562. va_end(ap);
  563. put_buffer(s, buf, strlen(buf));
  564. return ret;
  565. }
  566. #endif //CONFIG_MUXERS
  567. char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
  568. {
  569. int c;
  570. char *q;
  571. c = url_fgetc(s);
  572. if (c == EOF)
  573. return NULL;
  574. q = buf;
  575. for(;;) {
  576. if (c == EOF || c == '\n')
  577. break;
  578. if ((q - buf) < buf_size - 1)
  579. *q++ = c;
  580. c = url_fgetc(s);
  581. }
  582. if (buf_size > 0)
  583. *q = '\0';
  584. return buf;
  585. }
  586. int url_fget_max_packet_size(ByteIOContext *s)
  587. {
  588. return s->max_packet_size;
  589. }
  590. int av_url_read_fpause(ByteIOContext *s, int pause)
  591. {
  592. if (!s->read_pause)
  593. return AVERROR(ENOSYS);
  594. return s->read_pause(s->opaque, pause);
  595. }
  596. int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
  597. int64_t timestamp, int flags)
  598. {
  599. URLContext *h = s->opaque;
  600. int64_t ret;
  601. if (!s->read_seek)
  602. return AVERROR(ENOSYS);
  603. ret = s->read_seek(h, stream_index, timestamp, flags);
  604. if(ret >= 0) {
  605. s->buf_ptr = s->buf_end; // Flush buffer
  606. s->pos = s->seek(h, 0, SEEK_CUR);
  607. }
  608. return ret;
  609. }
  610. /* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
  611. * back to the server even if CONFIG_MUXERS is false. */
  612. #if CONFIG_MUXERS || CONFIG_NETWORK
  613. /* buffer handling */
  614. int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
  615. {
  616. int ret;
  617. *s = av_mallocz(sizeof(ByteIOContext));
  618. if(!*s)
  619. return AVERROR(ENOMEM);
  620. ret = init_put_byte(*s, buf, buf_size,
  621. (flags & URL_WRONLY || flags & URL_RDWR),
  622. NULL, NULL, NULL, NULL);
  623. if(ret != 0)
  624. av_freep(s);
  625. return ret;
  626. }
  627. int url_close_buf(ByteIOContext *s)
  628. {
  629. put_flush_packet(s);
  630. return s->buf_ptr - s->buffer;
  631. }
  632. /* output in a dynamic buffer */
  633. typedef struct DynBuffer {
  634. int pos, size, allocated_size;
  635. uint8_t *buffer;
  636. int io_buffer_size;
  637. uint8_t io_buffer[1];
  638. } DynBuffer;
  639. static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
  640. {
  641. DynBuffer *d = opaque;
  642. unsigned new_size, new_allocated_size;
  643. /* reallocate buffer if needed */
  644. new_size = d->pos + buf_size;
  645. new_allocated_size = d->allocated_size;
  646. if(new_size < d->pos || new_size > INT_MAX/2)
  647. return -1;
  648. while (new_size > new_allocated_size) {
  649. if (!new_allocated_size)
  650. new_allocated_size = new_size;
  651. else
  652. new_allocated_size += new_allocated_size / 2 + 1;
  653. }
  654. if (new_allocated_size > d->allocated_size) {
  655. d->buffer = av_realloc(d->buffer, new_allocated_size);
  656. if(d->buffer == NULL)
  657. return AVERROR(ENOMEM);
  658. d->allocated_size = new_allocated_size;
  659. }
  660. memcpy(d->buffer + d->pos, buf, buf_size);
  661. d->pos = new_size;
  662. if (d->pos > d->size)
  663. d->size = d->pos;
  664. return buf_size;
  665. }
  666. static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
  667. {
  668. unsigned char buf1[4];
  669. int ret;
  670. /* packetized write: output the header */
  671. AV_WB32(buf1, buf_size);
  672. ret= dyn_buf_write(opaque, buf1, 4);
  673. if(ret < 0)
  674. return ret;
  675. /* then the data */
  676. return dyn_buf_write(opaque, buf, buf_size);
  677. }
  678. static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
  679. {
  680. DynBuffer *d = opaque;
  681. if (whence == SEEK_CUR)
  682. offset += d->pos;
  683. else if (whence == SEEK_END)
  684. offset += d->size;
  685. if (offset < 0 || offset > 0x7fffffffLL)
  686. return -1;
  687. d->pos = offset;
  688. return 0;
  689. }
  690. static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
  691. {
  692. DynBuffer *d;
  693. int ret;
  694. unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
  695. if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
  696. return -1;
  697. d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
  698. if (!d)
  699. return AVERROR(ENOMEM);
  700. *s = av_mallocz(sizeof(ByteIOContext));
  701. if(!*s) {
  702. av_free(d);
  703. return AVERROR(ENOMEM);
  704. }
  705. d->io_buffer_size = io_buffer_size;
  706. ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
  707. 1, d, NULL,
  708. max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
  709. max_packet_size ? NULL : dyn_buf_seek);
  710. if (ret == 0) {
  711. (*s)->max_packet_size = max_packet_size;
  712. } else {
  713. av_free(d);
  714. av_freep(s);
  715. }
  716. return ret;
  717. }
  718. int url_open_dyn_buf(ByteIOContext **s)
  719. {
  720. return url_open_dyn_buf_internal(s, 0);
  721. }
  722. int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
  723. {
  724. if (max_packet_size <= 0)
  725. return -1;
  726. return url_open_dyn_buf_internal(s, max_packet_size);
  727. }
  728. int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
  729. {
  730. DynBuffer *d = s->opaque;
  731. int size;
  732. put_flush_packet(s);
  733. *pbuffer = d->buffer;
  734. size = d->size;
  735. av_free(d);
  736. av_free(s);
  737. return size;
  738. }
  739. #endif /* CONFIG_MUXERS || CONFIG_NETWORK */