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 !FF_API_URL_RESETBUF
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_nbyte(ByteIOContext *s, int b, int count)
119 int len = FFMIN(s->buf_end - s->buf_ptr, count);
120 memset(s->buf_ptr, b, len);
123 if (s->buf_ptr >= s->buf_end)
130 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
133 int len = FFMIN(s->buf_end - s->buf_ptr, size);
134 memcpy(s->buf_ptr, buf, len);
137 if (s->buf_ptr >= s->buf_end)
145 void put_flush_packet(ByteIOContext *s)
151 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence)
155 int force = whence & AVSEEK_FORCE;
156 whence &= ~AVSEEK_FORCE;
159 return AVERROR(EINVAL);
161 pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
163 if (whence != SEEK_CUR && whence != SEEK_SET)
164 return AVERROR(EINVAL);
166 if (whence == SEEK_CUR) {
167 offset1 = pos + (s->buf_ptr - s->buffer);
172 offset1 = offset - pos;
173 if (!s->must_flush &&
174 offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
175 /* can do the seek inside the buffer */
176 s->buf_ptr = s->buffer + offset1;
177 } else if ((s->is_streamed ||
178 offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
179 !s->write_flag && offset1 >= 0 &&
180 (whence != SEEK_END || force)) {
181 while(s->pos < offset && !s->eof_reached)
185 s->buf_ptr = s->buf_end + offset - s->pos;
189 #if CONFIG_MUXERS || CONFIG_NETWORK
194 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */
196 return AVERROR(EPIPE);
197 if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
200 s->buf_end = s->buffer;
201 s->buf_ptr = s->buffer;
208 int url_fskip(ByteIOContext *s, int64_t offset)
210 int64_t ret = url_fseek(s, offset, SEEK_CUR);
211 return ret < 0 ? ret : 0;
214 int64_t url_ftell(ByteIOContext *s)
216 return url_fseek(s, 0, SEEK_CUR);
219 int64_t url_fsize(ByteIOContext *s)
224 return AVERROR(EINVAL);
227 return AVERROR(ENOSYS);
228 size = s->seek(s->opaque, 0, AVSEEK_SIZE);
230 if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
233 s->seek(s->opaque, s->pos, SEEK_SET);
238 int url_feof(ByteIOContext *s)
242 return s->eof_reached;
245 int url_ferror(ByteIOContext *s)
252 void put_le32(ByteIOContext *s, unsigned int val)
255 put_byte(s, val >> 8);
256 put_byte(s, val >> 16);
257 put_byte(s, val >> 24);
260 void put_be32(ByteIOContext *s, unsigned int val)
262 put_byte(s, val >> 24);
263 put_byte(s, val >> 16);
264 put_byte(s, val >> 8);
268 void put_strz(ByteIOContext *s, const char *str)
271 put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
276 int ff_get_v_length(uint64_t val){
285 void ff_put_v(ByteIOContext *bc, uint64_t val){
286 int i= ff_get_v_length(val);
289 put_byte(bc, 128 | (val>>(7*i)));
291 put_byte(bc, val&127);
294 void put_le64(ByteIOContext *s, uint64_t val)
296 put_le32(s, (uint32_t)(val & 0xffffffff));
297 put_le32(s, (uint32_t)(val >> 32));
300 void put_be64(ByteIOContext *s, uint64_t val)
302 put_be32(s, (uint32_t)(val >> 32));
303 put_be32(s, (uint32_t)(val & 0xffffffff));
306 void put_le16(ByteIOContext *s, unsigned int val)
309 put_byte(s, val >> 8);
312 void put_be16(ByteIOContext *s, unsigned int val)
314 put_byte(s, val >> 8);
318 void put_le24(ByteIOContext *s, unsigned int val)
320 put_le16(s, val & 0xffff);
321 put_byte(s, val >> 16);
324 void put_be24(ByteIOContext *s, unsigned int val)
326 put_be16(s, val >> 8);
330 void put_tag(ByteIOContext *s, const char *tag)
339 static void fill_buffer(ByteIOContext *s)
341 uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_ptr : s->buffer;
342 int len= s->buffer_size - (dst - s->buffer);
343 int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
345 /* no need to do anything if EOF already reached */
349 if(s->update_checksum && dst == s->buffer){
350 if(s->buf_end > s->checksum_ptr)
351 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
352 s->checksum_ptr= s->buffer;
355 /* make buffer smaller in case it ended up large after probing */
356 if (s->buffer_size > max_buffer_size) {
357 url_setbufsize(s, max_buffer_size);
359 s->checksum_ptr = dst = s->buffer;
360 len = s->buffer_size;
364 len = s->read_packet(s->opaque, dst, len);
368 /* do not modify buffer if EOF reached so that a seek back can
369 be done without rereading data */
376 s->buf_end = dst + len;
380 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
383 return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
386 unsigned long get_checksum(ByteIOContext *s)
388 s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
389 s->update_checksum= NULL;
393 void init_checksum(ByteIOContext *s,
394 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
395 unsigned long checksum)
397 s->update_checksum= update_checksum;
398 if(s->update_checksum){
399 s->checksum= checksum;
400 s->checksum_ptr= s->buf_ptr;
404 /* XXX: put an inline version */
405 int get_byte(ByteIOContext *s)
407 if (s->buf_ptr >= s->buf_end)
409 if (s->buf_ptr < s->buf_end)
410 return *s->buf_ptr++;
414 int url_fgetc(ByteIOContext *s)
416 if (s->buf_ptr >= s->buf_end)
418 if (s->buf_ptr < s->buf_end)
419 return *s->buf_ptr++;
423 int get_buffer(ByteIOContext *s, unsigned char *buf, int size)
429 len = s->buf_end - s->buf_ptr;
433 if(size > s->buffer_size && !s->update_checksum){
435 len = s->read_packet(s->opaque, buf, size);
437 /* do not modify buffer if EOF reached so that a seek back can
438 be done without rereading data */
447 s->buf_ptr = s->buffer;
448 s->buf_end = s->buffer/* + len*/;
452 len = s->buf_end - s->buf_ptr;
457 memcpy(buf, s->buf_ptr, len);
464 if (url_ferror(s)) return url_ferror(s);
465 if (url_feof(s)) return AVERROR_EOF;
470 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size)
477 len = s->buf_end - s->buf_ptr;
480 len = s->buf_end - s->buf_ptr;
484 memcpy(buf, s->buf_ptr, len);
487 if (url_ferror(s)) return url_ferror(s);
488 if (url_feof(s)) return AVERROR_EOF;
493 unsigned int get_le16(ByteIOContext *s)
497 val |= get_byte(s) << 8;
501 unsigned int get_le24(ByteIOContext *s)
505 val |= get_byte(s) << 16;
509 unsigned int get_le32(ByteIOContext *s)
513 val |= get_le16(s) << 16;
517 uint64_t get_le64(ByteIOContext *s)
520 val = (uint64_t)get_le32(s);
521 val |= (uint64_t)get_le32(s) << 32;
525 unsigned int get_be16(ByteIOContext *s)
528 val = get_byte(s) << 8;
533 unsigned int get_be24(ByteIOContext *s)
536 val = get_be16(s) << 8;
540 unsigned int get_be32(ByteIOContext *s)
543 val = get_be16(s) << 16;
548 char *get_strz(ByteIOContext *s, char *buf, int maxlen)
553 while ((c = get_byte(s))) {
558 buf[i] = 0; /* Ensure null terminated, but may be truncated */
563 int ff_get_line(ByteIOContext *s, char *buf, int maxlen)
570 if (c && i < maxlen-1)
572 } while (c != '\n' && c);
578 uint64_t get_be64(ByteIOContext *s)
581 val = (uint64_t)get_be32(s) << 32;
582 val |= (uint64_t)get_be32(s);
586 uint64_t ff_get_v(ByteIOContext *bc){
592 val= (val<<7) + (tmp&127);
597 int url_fdopen(ByteIOContext **s, URLContext *h)
600 int buffer_size, max_packet_size;
602 max_packet_size = url_get_max_packet_size(h);
603 if (max_packet_size) {
604 buffer_size = max_packet_size; /* no need to bufferize more than one packet */
606 buffer_size = IO_BUFFER_SIZE;
608 buffer = av_malloc(buffer_size);
610 return AVERROR(ENOMEM);
612 *s = av_mallocz(sizeof(ByteIOContext));
615 return AVERROR(ENOMEM);
618 if (init_put_byte(*s, buffer, buffer_size,
619 (h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
620 url_read, url_write, url_seek) < 0) {
625 (*s)->is_streamed = h->is_streamed;
626 (*s)->max_packet_size = max_packet_size;
628 (*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
629 (*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
634 int url_setbufsize(ByteIOContext *s, int buf_size)
637 buffer = av_malloc(buf_size);
639 return AVERROR(ENOMEM);
643 s->buffer_size = buf_size;
645 url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
649 #if FF_API_URL_RESETBUF
650 int url_resetbuf(ByteIOContext *s, int flags)
652 static int url_resetbuf(ByteIOContext *s, int flags)
655 #if FF_API_URL_RESETBUF
656 if (flags & URL_RDWR)
657 return AVERROR(EINVAL);
659 assert(flags == URL_WRONLY || flags == URL_RDONLY);
662 if (flags & URL_WRONLY) {
663 s->buf_end = s->buffer + s->buffer_size;
666 s->buf_end = s->buffer;
672 int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size)
674 int64_t buffer_start;
676 int overlap, new_size, alloc_size;
679 return AVERROR(EINVAL);
681 buffer_size = s->buf_end - s->buffer;
683 /* the buffers must touch or overlap */
684 if ((buffer_start = s->pos - buffer_size) > buf_size)
685 return AVERROR(EINVAL);
687 overlap = buf_size - buffer_start;
688 new_size = buf_size + buffer_size - overlap;
690 alloc_size = FFMAX(s->buffer_size, new_size);
691 if (alloc_size > buf_size)
692 if (!(buf = av_realloc(buf, alloc_size)))
693 return AVERROR(ENOMEM);
695 if (new_size > buf_size) {
696 memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
701 s->buf_ptr = s->buffer = buf;
702 s->buffer_size = alloc_size;
704 s->buf_end = s->buf_ptr + buf_size;
711 int url_fopen(ByteIOContext **s, const char *filename, int flags)
716 err = url_open(&h, filename, flags);
719 err = url_fdopen(s, h);
727 int url_fclose(ByteIOContext *s)
729 URLContext *h = s->opaque;
736 URLContext *url_fileno(ByteIOContext *s)
742 int url_fprintf(ByteIOContext *s, const char *fmt, ...)
749 ret = vsnprintf(buf, sizeof(buf), fmt, ap);
751 put_buffer(s, buf, strlen(buf));
754 #endif //CONFIG_MUXERS
756 char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
766 if (c == EOF || c == '\n')
768 if ((q - buf) < buf_size - 1)
777 int url_fget_max_packet_size(ByteIOContext *s)
779 return s->max_packet_size;
782 int av_url_read_fpause(ByteIOContext *s, int pause)
785 return AVERROR(ENOSYS);
786 return s->read_pause(s->opaque, pause);
789 int64_t av_url_read_fseek(ByteIOContext *s, int stream_index,
790 int64_t timestamp, int flags)
792 URLContext *h = s->opaque;
795 return AVERROR(ENOSYS);
796 ret = s->read_seek(h, stream_index, timestamp, flags);
799 s->buf_ptr = s->buf_end; // Flush buffer
800 pos = s->seek(h, 0, SEEK_CUR);
803 else if (pos != AVERROR(ENOSYS))
809 /* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
810 * back to the server even if CONFIG_MUXERS is false. */
811 #if CONFIG_MUXERS || CONFIG_NETWORK
812 /* buffer handling */
813 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags)
816 *s = av_mallocz(sizeof(ByteIOContext));
818 return AVERROR(ENOMEM);
819 ret = init_put_byte(*s, buf, buf_size,
820 (flags & URL_WRONLY || flags & URL_RDWR),
821 NULL, NULL, NULL, NULL);
827 int url_close_buf(ByteIOContext *s)
830 return s->buf_ptr - s->buffer;
833 /* output in a dynamic buffer */
835 typedef struct DynBuffer {
836 int pos, size, allocated_size;
839 uint8_t io_buffer[1];
842 static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
844 DynBuffer *d = opaque;
845 unsigned new_size, new_allocated_size;
847 /* reallocate buffer if needed */
848 new_size = d->pos + buf_size;
849 new_allocated_size = d->allocated_size;
850 if(new_size < d->pos || new_size > INT_MAX/2)
852 while (new_size > new_allocated_size) {
853 if (!new_allocated_size)
854 new_allocated_size = new_size;
856 new_allocated_size += new_allocated_size / 2 + 1;
859 if (new_allocated_size > d->allocated_size) {
860 d->buffer = av_realloc(d->buffer, new_allocated_size);
861 if(d->buffer == NULL)
862 return AVERROR(ENOMEM);
863 d->allocated_size = new_allocated_size;
865 memcpy(d->buffer + d->pos, buf, buf_size);
867 if (d->pos > d->size)
872 static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
874 unsigned char buf1[4];
877 /* packetized write: output the header */
878 AV_WB32(buf1, buf_size);
879 ret= dyn_buf_write(opaque, buf1, 4);
884 return dyn_buf_write(opaque, buf, buf_size);
887 static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
889 DynBuffer *d = opaque;
891 if (whence == SEEK_CUR)
893 else if (whence == SEEK_END)
895 if (offset < 0 || offset > 0x7fffffffLL)
901 static int url_open_dyn_buf_internal(ByteIOContext **s, int max_packet_size)
905 unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
907 if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
909 d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
911 return AVERROR(ENOMEM);
912 *s = av_mallocz(sizeof(ByteIOContext));
915 return AVERROR(ENOMEM);
917 d->io_buffer_size = io_buffer_size;
918 ret = init_put_byte(*s, d->io_buffer, io_buffer_size,
920 max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
921 max_packet_size ? NULL : dyn_buf_seek);
923 (*s)->max_packet_size = max_packet_size;
931 int url_open_dyn_buf(ByteIOContext **s)
933 return url_open_dyn_buf_internal(s, 0);
936 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size)
938 if (max_packet_size <= 0)
940 return url_open_dyn_buf_internal(s, max_packet_size);
943 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
945 DynBuffer *d = s->opaque;
947 static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
950 /* don't attempt to pad fixed-size packet buffers */
951 if (!s->max_packet_size) {
952 put_buffer(s, padbuf, sizeof(padbuf));
953 padding = FF_INPUT_BUFFER_PADDING_SIZE;
958 *pbuffer = d->buffer;
962 return size - padding;
964 #endif /* CONFIG_MUXERS || CONFIG_NETWORK */