2 * Buffered I/O for ffmpeg system
3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/crc.h"
23 #include "libavutil/intreadwrite.h"
29 #define IO_BUFFER_SIZE 32768
32 * Do seeks within this distance ahead of the current buffer by skipping
33 * data instead of calling the protocol seek function, for seekable
36 #define SHORT_SEEK_THRESHOLD 4096
38 static void fill_buffer(ByteIOContext *s);
39 #if LIBAVFORMAT_VERSION_MAJOR >= 53
40 static int url_resetbuf(ByteIOContext *s, int flags);
43 int init_put_byte(ByteIOContext *s,
44 unsigned char *buffer,
48 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
49 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
50 int64_t (*seek)(void *opaque, int64_t offset, int whence))
53 s->buffer_size = buffer_size;
56 url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
57 s->write_packet = write_packet;
58 s->read_packet = read_packet;
65 s->max_packet_size = 0;
66 s->update_checksum= NULL;
67 if(!read_packet && !write_flag){
69 s->buf_end = s->buffer + buffer_size;
76 ByteIOContext *av_alloc_put_byte(
77 unsigned char *buffer,
81 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
82 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
83 int64_t (*seek)(void *opaque, int64_t offset, int whence))
85 ByteIOContext *s = av_mallocz(sizeof(ByteIOContext));
86 init_put_byte(s, buffer, buffer_size, write_flag, opaque,
87 read_packet, write_packet, seek);
91 static void flush_buffer(ByteIOContext *s)
93 if (s->buf_ptr > s->buffer) {
94 if (s->write_packet && !s->error){
95 int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
100 if(s->update_checksum){
101 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
102 s->checksum_ptr= s->buffer;
104 s->pos += s->buf_ptr - s->buffer;
106 s->buf_ptr = s->buffer;
109 void put_byte(ByteIOContext *s, int b)
112 if (s->buf_ptr >= s->buf_end)
116 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
119 int len = FFMIN(s->buf_end - s->buf_ptr, size);
120 memcpy(s->buf_ptr, buf, len);
123 if (s->buf_ptr >= s->buf_end)
131 void put_flush_packet(ByteIOContext *s)
137 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
141 int force = whence & AVSEEK_FORCE;
142 whence &= ~AVSEEK_FORCE;
145 return AVERROR(EINVAL);
147 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
149 if (whence != SEEK_CUR && whence != SEEK_SET)
150 return AVERROR(EINVAL);
152 if (whence == SEEK_CUR) {
153 offset1 = pos + (s->buf_ptr - s->buffer);
158 offset1 = offset - pos;
159 if (!s->must_flush &&
160 offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
161 /* can do the seek inside the buffer */
162 s->buf_ptr = s->buffer + offset1;
163 } else if ((s->is_streamed ||
164 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
165 !s->write_flag && offset1 >= 0 &&
166 (whence != SEEK_END || force)) {
167 while(s->pos < offset && !s->eof_reached)
171 s->buf_ptr = s->buf_end + offset - s->pos;
175 #if CONFIG_MUXERS || CONFIG_NETWORK
180 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
182 return AVERROR(EPIPE);
183 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
186 s->buf_end = s->buffer;
187 s->buf_ptr = s->buffer;
194 int url_fskip(ByteIOContext *s, int64_t offset)
196 int64_t ret = url_fseek(s, offset, SEEK_CUR);
197 return ret < 0 ? ret : 0;
200 int64_t url_ftell(ByteIOContext *s)
202 return url_fseek(s, 0, SEEK_CUR);
205 int64_t url_fsize(ByteIOContext *s)
210 return AVERROR(EINVAL);
213 return AVERROR(ENOSYS);
214 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
216 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
219 s->seek(s->opaque, s->pos, SEEK_SET);
224 int url_feof(ByteIOContext *s)
228 return s->eof_reached;
231 int url_ferror(ByteIOContext *s)
238 void put_le32(ByteIOContext *s, unsigned int val)
241 put_byte(s, val >> 8);
242 put_byte(s, val >> 16);
243 put_byte(s, val >> 24);
246 void put_be32(ByteIOContext *s, unsigned int val)
248 put_byte(s, val >> 24);
249 put_byte(s, val >> 16);
250 put_byte(s, val >> 8);
254 void put_strz(ByteIOContext *s, const char *str)
257 put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
262 int ff_get_v_length(uint64_t val){
271 void ff_put_v(ByteIOContext *bc, uint64_t val){
272 int i= ff_get_v_length(val);
275 put_byte(bc, 128 | (val>>(7*i)));
277 put_byte(bc, val&127);
280 void put_le64(ByteIOContext *s, uint64_t val)
282 put_le32(s, (uint32_t)(val & 0xffffffff));
283 put_le32(s, (uint32_t)(val >> 32));
286 void put_be64(ByteIOContext *s, uint64_t val)
288 put_be32(s, (uint32_t)(val >> 32));
289 put_be32(s, (uint32_t)(val & 0xffffffff));
292 void put_le16(ByteIOContext *s, unsigned int val)
295 put_byte(s, val >> 8);
298 void put_be16(ByteIOContext *s, unsigned int val)
300 put_byte(s, val >> 8);
304 void put_le24(ByteIOContext *s, unsigned int val)
306 put_le16(s, val & 0xffff);
307 put_byte(s, val >> 16);
310 void put_be24(ByteIOContext *s, unsigned int val)
312 put_be16(s, val >> 8);
316 void put_tag(ByteIOContext *s, const char *tag)
325 static void fill_buffer(ByteIOContext *s)
327 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
328 int len= s->buffer_size - (dst - s->buffer);
329 int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
331 /* no need to do anything if EOF already reached */
335 if(s->update_checksum && dst == s->buffer){
336 if(s->buf_end > s->checksum_ptr)
337 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
338 s->checksum_ptr= s->buffer;
341 /* make buffer smaller in case it ended up large after probing */
342 if (s->buffer_size > max_buffer_size) {
343 url_setbufsize(s, max_buffer_size);
345 s->checksum_ptr = dst = s->buffer;
346 len = s->buffer_size;
350 len = s->read_packet(s->opaque, dst, len);
354 /* do not modify buffer if EOF reached so that a seek back can
355 be done without rereading data */
362 s->buf_end = dst + len;
366 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
369 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
372 unsigned long get_checksum(ByteIOContext *s)
374 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
375 s->update_checksum= NULL;
379 void init_checksum(ByteIOContext *s,
380 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
381 unsigned long checksum)
383 s->update_checksum= update_checksum;
384 if(s->update_checksum){
385 s->checksum= checksum;
386 s->checksum_ptr= s->buf_ptr;
390 /* XXX: put an inline version */
391 int get_byte(ByteIOContext *s)
393 if (s->buf_ptr < s->buf_end) {
394 return *s->buf_ptr++;
397 if (s->buf_ptr < s->buf_end)
398 return *s->buf_ptr++;
404 int url_fgetc(ByteIOContext *s)
406 if (s->buf_ptr < s->buf_end) {
407 return *s->buf_ptr++;
410 if (s->buf_ptr < s->buf_end)
411 return *s->buf_ptr++;
417 int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
423 len = s->buf_end - s->buf_ptr;
427 if(size > s->buffer_size && !s->update_checksum){
429 len = s->read_packet(s->opaque, buf, size);
431 /* do not modify buffer if EOF reached so that a seek back can
432 be done without rereading data */
441 s->buf_ptr = s->buffer;
442 s->buf_end = s->buffer/* + len*/;
446 len = s->buf_end - s->buf_ptr;
451 memcpy(buf, s->buf_ptr, len);
458 if (url_ferror(s)) return url_ferror(s);
459 if (url_feof(s)) return AVERROR_EOF;
464 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
471 len = s->buf_end - s->buf_ptr;
474 len = s->buf_end - s->buf_ptr;
478 memcpy(buf, s->buf_ptr, len);
481 if (url_ferror(s)) return url_ferror(s);
482 if (url_feof(s)) return AVERROR_EOF;
487 unsigned int get_le16(ByteIOContext *s)
491 val |= get_byte(s) << 8;
495 unsigned int get_le24(ByteIOContext *s)
499 val |= get_byte(s) << 16;
503 unsigned int get_le32(ByteIOContext *s)
507 val |= get_le16(s) << 16;
511 uint64_t get_le64(ByteIOContext *s)
514 val = (uint64_t)get_le32(s);
515 val |= (uint64_t)get_le32(s) << 32;
519 unsigned int get_be16(ByteIOContext *s)
522 val = get_byte(s) << 8;
527 unsigned int get_be24(ByteIOContext *s)
530 val = get_be16(s) << 8;
534 unsigned int get_be32(ByteIOContext *s)
537 val = get_be16(s) << 16;
542 char *get_strz(ByteIOContext *s, char *buf, int maxlen)
547 while ((c = get_byte(s))) {
552 buf[i] = 0; /* Ensure null terminated, but may be truncated */
557 uint64_t get_be64(ByteIOContext *s)
560 val = (uint64_t)get_be32(s) << 32;
561 val |= (uint64_t)get_be32(s);
565 uint64_t ff_get_v(ByteIOContext *bc){
571 val= (val<<7) + (tmp&127);
576 int url_fdopen(ByteIOContext **s, URLContext *h)
579 int buffer_size, max_packet_size;
581 max_packet_size = url_get_max_packet_size(h);
582 if (max_packet_size) {
583 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
585 buffer_size = IO_BUFFER_SIZE;
587 buffer = av_malloc(buffer_size);
589 return AVERROR(ENOMEM);
591 *s = av_mallocz(sizeof(ByteIOContext));
594 return AVERROR(ENOMEM);
597 if (init_put_byte(*s, buffer, buffer_size,
598 (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
599 url_read, url_write, url_seek) < 0) {
604 (*s)->is_streamed = h->is_streamed;
605 (*s)->max_packet_size = max_packet_size;
607 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
608 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
613 int url_setbufsize(ByteIOContext *s, int buf_size)
616 buffer = av_malloc(buf_size);
618 return AVERROR(ENOMEM);
622 s->buffer_size = buf_size;
624 url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
628 #if LIBAVFORMAT_VERSION_MAJOR < 53
629 int url_resetbuf(ByteIOContext *s, int flags)
631 static int url_resetbuf(ByteIOContext *s, int flags)
634 #if LIBAVFORMAT_VERSION_MAJOR < 53
635 if (flags & URL_RDWR)
636 return AVERROR(EINVAL);
638 assert(flags == URL_WRONLY || flags == URL_RDONLY);
641 if (flags & URL_WRONLY) {
642 s->buf_end = s->buffer + s->buffer_size;
645 s->buf_end = s->buffer;
651 int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
653 int64_t buffer_start;
655 int overlap, new_size;
658 return AVERROR(EINVAL);
660 buffer_size = s->buf_end - s->buffer;
662 /* the buffers must touch or overlap */
663 if ((buffer_start = s->pos - buffer_size) > buf_size)
664 return AVERROR(EINVAL);
666 overlap = buf_size - buffer_start;
667 new_size = buf_size + buffer_size - overlap;
669 if (new_size > buf_size) {
670 if (!(buf = av_realloc(buf, new_size)))
671 return AVERROR(ENOMEM);
673 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
678 s->buf_ptr = s->buffer = buf;
679 s->pos = s->buffer_size = buf_size;
680 s->buf_end = s->buf_ptr + buf_size;
687 int url_fopen(ByteIOContext **s, const char *filename, int flags)
692 err = url_open(&h, filename, flags);
695 err = url_fdopen(s, h);
703 int url_fclose(ByteIOContext *s)
705 URLContext *h = s->opaque;
712 URLContext *url_fileno(ByteIOContext *s)
718 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
725 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
727 put_buffer(s, buf, strlen(buf));
730 #endif //CONFIG_MUXERS
732 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
742 if (c == EOF || c == '\n')
744 if ((q - buf) < buf_size - 1)
753 int url_fget_max_packet_size(ByteIOContext *s)
755 return s->max_packet_size;
758 int av_url_read_fpause(ByteIOContext *s, int pause)
761 return AVERROR(ENOSYS);
762 return s->read_pause(s->opaque, pause);
765 int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
766 int64_t timestamp, int flags)
768 URLContext *h = s->opaque;
771 return AVERROR(ENOSYS);
772 ret = s->read_seek(h, stream_index, timestamp, flags);
775 s->buf_ptr = s->buf_end; // Flush buffer
776 pos = s->seek(h, 0, SEEK_CUR);
779 else if (pos != AVERROR(ENOSYS))
785 /* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
786 * back to the server even if CONFIG_MUXERS is false. */
787 #if CONFIG_MUXERS || CONFIG_NETWORK
788 /* buffer handling */
789 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
792 *s = av_mallocz(sizeof(ByteIOContext));
794 return AVERROR(ENOMEM);
795 ret = init_put_byte(*s, buf, buf_size,
796 (flags & URL_WRONLY || flags & URL_RDWR),
797 NULL, NULL, NULL, NULL);
803 int url_close_buf(ByteIOContext *s)
806 return s->buf_ptr - s->buffer;
809 /* output in a dynamic buffer */
811 typedef struct DynBuffer {
812 int pos, size, allocated_size;
815 uint8_t io_buffer[1];
818 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
820 DynBuffer *d = opaque;
821 unsigned new_size, new_allocated_size;
823 /* reallocate buffer if needed */
824 new_size = d->pos + buf_size;
825 new_allocated_size = d->allocated_size;
826 if(new_size < d->pos || new_size > INT_MAX/2)
828 while (new_size > new_allocated_size) {
829 if (!new_allocated_size)
830 new_allocated_size = new_size;
832 new_allocated_size += new_allocated_size / 2 + 1;
835 if (new_allocated_size > d->allocated_size) {
836 d->buffer = av_realloc(d->buffer, new_allocated_size);
837 if(d->buffer == NULL)
838 return AVERROR(ENOMEM);
839 d->allocated_size = new_allocated_size;
841 memcpy(d->buffer + d->pos, buf, buf_size);
843 if (d->pos > d->size)
848 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
850 unsigned char buf1[4];
853 /* packetized write: output the header */
854 AV_WB32(buf1, buf_size);
855 ret= dyn_buf_write(opaque, buf1, 4);
860 return dyn_buf_write(opaque, buf, buf_size);
863 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
865 DynBuffer *d = opaque;
867 if (whence == SEEK_CUR)
869 else if (whence == SEEK_END)
871 if (offset < 0 || offset > 0x7fffffffLL)
877 static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
881 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
883 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
885 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
887 return AVERROR(ENOMEM);
888 *s = av_mallocz(sizeof(ByteIOContext));
891 return AVERROR(ENOMEM);
893 d->io_buffer_size = io_buffer_size;
894 ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
896 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
897 max_packet_size ? NULL : dyn_buf_seek);
899 (*s)->max_packet_size = max_packet_size;
907 int url_open_dyn_buf(ByteIOContext **s)
909 return url_open_dyn_buf_internal(s, 0);
912 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
914 if (max_packet_size <= 0)
916 return url_open_dyn_buf_internal(s, max_packet_size);
919 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
921 DynBuffer *d = s->opaque;
923 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
926 /* don't attempt to pad fixed-size packet buffers */
927 if (!s->max_packet_size) {
928 put_buffer(s, padbuf, sizeof(padbuf));
929 padding = FF_INPUT_BUFFER_PADDING_SIZE;
934 *pbuffer = d->buffer;
938 return size - padding;
940 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */