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ffmpeg/libavformat/aviobuf.c

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/*
* Buffered I/O for ffmpeg system
* Copyright (c) 2000,2001 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/crc.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio.h"
#include "avio_internal.h"
#include "internal.h"
#include <stdarg.h>
#define IO_BUFFER_SIZE 32768
/**
* Do seeks within this distance ahead of the current buffer by skipping
* data instead of calling the protocol seek function, for seekable
* protocols.
*/
#define SHORT_SEEK_THRESHOLD 4096
static void fill_buffer(AVIOContext *s);
#if !FF_API_URL_RESETBUF
static int url_resetbuf(AVIOContext *s, int flags);
#endif
int ffio_init_context(AVIOContext *s,
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
int64_t (*seek)(void *opaque, int64_t offset, int whence))
{
s->buffer = buffer;
s->buffer_size = buffer_size;
s->buf_ptr = buffer;
s->opaque = opaque;
url_resetbuf(s, write_flag ? URL_WRONLY : URL_RDONLY);
s->write_packet = write_packet;
s->read_packet = read_packet;
s->seek = seek;
s->pos = 0;
s->must_flush = 0;
s->eof_reached = 0;
s->error = 0;
s->is_streamed = 0;
s->max_packet_size = 0;
s->update_checksum= NULL;
if(!read_packet && !write_flag){
s->pos = buffer_size;
s->buf_end = s->buffer + buffer_size;
}
s->read_pause = NULL;
s->read_seek = NULL;
return 0;
}
#if FF_API_OLD_AVIO
int init_put_byte(AVIOContext *s,
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
int64_t (*seek)(void *opaque, int64_t offset, int whence))
{
return ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
read_packet, write_packet, seek);
}
AVIOContext *av_alloc_put_byte(
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
int64_t (*seek)(void *opaque, int64_t offset, int whence))
{
return avio_alloc_context(buffer, buffer_size, write_flag, opaque,
read_packet, write_packet, seek);
}
#endif
AVIOContext *avio_alloc_context(
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
int64_t (*seek)(void *opaque, int64_t offset, int whence))
{
AVIOContext *s = av_mallocz(sizeof(AVIOContext));
ffio_init_context(s, buffer, buffer_size, write_flag, opaque,
read_packet, write_packet, seek);
return s;
}
static void flush_buffer(AVIOContext *s)
{
if (s->buf_ptr > s->buffer) {
if (s->write_packet && !s->error){
int ret= s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
if(ret < 0){
s->error = ret;
}
}
if(s->update_checksum){
s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
s->checksum_ptr= s->buffer;
}
s->pos += s->buf_ptr - s->buffer;
}
s->buf_ptr = s->buffer;
}
void avio_w8(AVIOContext *s, int b)
{
*(s->buf_ptr)++ = b;
if (s->buf_ptr >= s->buf_end)
flush_buffer(s);
}
void ffio_fill(AVIOContext *s, int b, int count)
{
while (count > 0) {
int len = FFMIN(s->buf_end - s->buf_ptr, count);
memset(s->buf_ptr, b, len);
s->buf_ptr += len;
if (s->buf_ptr >= s->buf_end)
flush_buffer(s);
count -= len;
}
}
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
{
while (size > 0) {
int len = FFMIN(s->buf_end - s->buf_ptr, size);
memcpy(s->buf_ptr, buf, len);
s->buf_ptr += len;
if (s->buf_ptr >= s->buf_end)
flush_buffer(s);
buf += len;
size -= len;
}
}
void put_flush_packet(AVIOContext *s)
{
flush_buffer(s);
s->must_flush = 0;
}
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
{
int64_t offset1;
int64_t pos;
int force = whence & AVSEEK_FORCE;
whence &= ~AVSEEK_FORCE;
if(!s)
return AVERROR(EINVAL);
pos = s->pos - (s->write_flag ? 0 : (s->buf_end - s->buffer));
if (whence != SEEK_CUR && whence != SEEK_SET)
return AVERROR(EINVAL);
if (whence == SEEK_CUR) {
offset1 = pos + (s->buf_ptr - s->buffer);
if (offset == 0)
return offset1;
offset += offset1;
}
offset1 = offset - pos;
if (!s->must_flush &&
offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
/* can do the seek inside the buffer */
s->buf_ptr = s->buffer + offset1;
} else if ((s->is_streamed ||
offset1 <= s->buf_end + SHORT_SEEK_THRESHOLD - s->buffer) &&
!s->write_flag && offset1 >= 0 &&
(whence != SEEK_END || force)) {
while(s->pos < offset && !s->eof_reached)
fill_buffer(s);
if (s->eof_reached)
return AVERROR_EOF;
s->buf_ptr = s->buf_end + offset - s->pos;
} else {
int64_t res;
#if CONFIG_MUXERS || CONFIG_NETWORK
if (s->write_flag) {
flush_buffer(s);
s->must_flush = 1;
}
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */
if (!s->seek)
return AVERROR(EPIPE);
if ((res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
return res;
if (!s->write_flag)
s->buf_end = s->buffer;
s->buf_ptr = s->buffer;
s->pos = offset;
}
s->eof_reached = 0;
return offset;
}
#if FF_API_OLD_AVIO
int url_fskip(AVIOContext *s, int64_t offset)
{
int64_t ret = avio_seek(s, offset, SEEK_CUR);
return ret < 0 ? ret : 0;
}
int64_t url_ftell(AVIOContext *s)
{
return avio_seek(s, 0, SEEK_CUR);
}
#endif
int64_t avio_size(AVIOContext *s)
{
int64_t size;
if(!s)
return AVERROR(EINVAL);
if (!s->seek)
return AVERROR(ENOSYS);
size = s->seek(s->opaque, 0, AVSEEK_SIZE);
if(size<0){
if ((size = s->seek(s->opaque, -1, SEEK_END)) < 0)
return size;
size++;
s->seek(s->opaque, s->pos, SEEK_SET);
}
return size;
}
#if FF_API_OLD_AVIO
int url_feof(AVIOContext *s)
{
if(!s)
return 0;
return s->eof_reached;
}
int url_ferror(AVIOContext *s)
{
if(!s)
return 0;
return s->error;
}
#endif
void avio_wl32(AVIOContext *s, unsigned int val)
{
avio_w8(s, val);
avio_w8(s, val >> 8);
avio_w8(s, val >> 16);
avio_w8(s, val >> 24);
}
void avio_wb32(AVIOContext *s, unsigned int val)
{
avio_w8(s, val >> 24);
avio_w8(s, val >> 16);
avio_w8(s, val >> 8);
avio_w8(s, val);
}
#if FF_API_OLD_AVIO
void put_strz(AVIOContext *s, const char *str)
{
avio_put_str(s, str);
}
#define GET(name, type) \
type get_be ##name(AVIOContext *s) \
{\
return avio_rb ##name(s);\
}\
type get_le ##name(AVIOContext *s) \
{\
return avio_rl ##name(s);\
}
GET(16, unsigned int)
GET(24, unsigned int)
GET(32, unsigned int)
GET(64, uint64_t)
#undef GET
#define PUT(name, type ) \
void put_le ##name(AVIOContext *s, type val)\
{\
avio_wl ##name(s, val);\
}\
void put_be ##name(AVIOContext *s, type val)\
{\
avio_wb ##name(s, val);\
}
PUT(16, unsigned int)
PUT(24, unsigned int)
PUT(32, unsigned int)
PUT(64, uint64_t)
#undef PUT
int get_byte(AVIOContext *s)
{
return avio_r8(s);
}
int get_buffer(AVIOContext *s, unsigned char *buf, int size)
{
return avio_read(s, buf, size);
}
int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size)
{
return ffio_read_partial(s, buf, size);
}
void put_byte(AVIOContext *s, int val)
{
avio_w8(s, val);
}
void put_buffer(AVIOContext *s, const unsigned char *buf, int size)
{
avio_write(s, buf, size);
}
void put_nbyte(AVIOContext *s, int b, int count)
{
ffio_fill(s, b, count);
}
int url_fopen(AVIOContext **s, const char *filename, int flags)
{
return avio_open(s, filename, flags);
}
int url_fclose(AVIOContext *s)
{
return avio_close(s);
}
int64_t url_fseek(AVIOContext *s, int64_t offset, int whence)
{
return avio_seek(s, offset, whence);
}
int64_t url_fsize(AVIOContext *s)
{
return avio_size(s);
}
#endif
int avio_put_str(AVIOContext *s, const char *str)
{
int len = 1;
if (str) {
len += strlen(str);
avio_write(s, (const unsigned char *) str, len);
} else
avio_w8(s, 0);
return len;
}
int avio_put_str16le(AVIOContext *s, const char *str)
{
const uint8_t *q = str;
int ret = 0;
while (*q) {
uint32_t ch;
uint16_t tmp;
GET_UTF8(ch, *q++, break;)
PUT_UTF16(ch, tmp, avio_wl16(s, tmp);ret += 2;)
}
avio_wl16(s, 0);
ret += 2;
return ret;
}
int ff_get_v_length(uint64_t val){
int i=1;
while(val>>=7)
i++;
return i;
}
void ff_put_v(AVIOContext *bc, uint64_t val){
int i= ff_get_v_length(val);
while(--i>0)
avio_w8(bc, 128 | (val>>(7*i)));
avio_w8(bc, val&127);
}
void avio_wl64(AVIOContext *s, uint64_t val)
{
avio_wl32(s, (uint32_t)(val & 0xffffffff));
avio_wl32(s, (uint32_t)(val >> 32));
}
void avio_wb64(AVIOContext *s, uint64_t val)
{
avio_wb32(s, (uint32_t)(val >> 32));
avio_wb32(s, (uint32_t)(val & 0xffffffff));
}
void avio_wl16(AVIOContext *s, unsigned int val)
{
avio_w8(s, val);
avio_w8(s, val >> 8);
}
void avio_wb16(AVIOContext *s, unsigned int val)
{
avio_w8(s, val >> 8);
avio_w8(s, val);
}
void avio_wl24(AVIOContext *s, unsigned int val)
{
avio_wl16(s, val & 0xffff);
avio_w8(s, val >> 16);
}
void avio_wb24(AVIOContext *s, unsigned int val)
{
avio_wb16(s, val >> 8);
avio_w8(s, val);
}
#if FF_API_OLD_AVIO
void put_tag(AVIOContext *s, const char *tag)
{
while (*tag) {
avio_w8(s, *tag++);
}
}
#endif
/* Input stream */
static void fill_buffer(AVIOContext *s)
{
uint8_t *dst= !s->max_packet_size && s->buf_end - s->buffer < s->buffer_size ? s->buf_end : s->buffer;
int len= s->buffer_size - (dst - s->buffer);
int max_buffer_size = s->max_packet_size ? s->max_packet_size : IO_BUFFER_SIZE;
/* no need to do anything if EOF already reached */
if (s->eof_reached)
return;
if(s->update_checksum && dst == s->buffer){
if(s->buf_end > s->checksum_ptr)
s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
s->checksum_ptr= s->buffer;
}
/* make buffer smaller in case it ended up large after probing */
if (s->buffer_size > max_buffer_size) {
url_setbufsize(s, max_buffer_size);
s->checksum_ptr = dst = s->buffer;
len = s->buffer_size;
}
if(s->read_packet)
len = s->read_packet(s->opaque, dst, len);
else
len = 0;
if (len <= 0) {
/* do not modify buffer if EOF reached so that a seek back can
be done without rereading data */
s->eof_reached = 1;
if(len<0)
s->error= len;
} else {
s->pos += len;
s->buf_ptr = dst;
s->buf_end = dst + len;
}
}
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
unsigned int len)
{
return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
}
unsigned long get_checksum(AVIOContext *s)
{
s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_ptr - s->checksum_ptr);
s->update_checksum= NULL;
return s->checksum;
}
void init_checksum(AVIOContext *s,
unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
unsigned long checksum)
{
s->update_checksum= update_checksum;
if(s->update_checksum){
s->checksum= checksum;
s->checksum_ptr= s->buf_ptr;
}
}
/* XXX: put an inline version */
int avio_r8(AVIOContext *s)
{
if (s->buf_ptr >= s->buf_end)
fill_buffer(s);
if (s->buf_ptr < s->buf_end)
return *s->buf_ptr++;
return 0;
}
#if FF_API_OLD_AVIO
int url_fgetc(AVIOContext *s)
{
if (s->buf_ptr >= s->buf_end)
fill_buffer(s);
if (s->buf_ptr < s->buf_end)
return *s->buf_ptr++;
return URL_EOF;
}
#endif
int avio_read(AVIOContext *s, unsigned char *buf, int size)
{
int len, size1;
size1 = size;
while (size > 0) {
len = s->buf_end - s->buf_ptr;
if (len > size)
len = size;
if (len == 0) {
if(size > s->buffer_size && !s->update_checksum){
if(s->read_packet)
len = s->read_packet(s->opaque, buf, size);
if (len <= 0) {
/* do not modify buffer if EOF reached so that a seek back can
be done without rereading data */
s->eof_reached = 1;
if(len<0)
s->error= len;
break;
} else {
s->pos += len;
size -= len;
buf += len;
s->buf_ptr = s->buffer;
s->buf_end = s->buffer/* + len*/;
}
}else{
fill_buffer(s);
len = s->buf_end - s->buf_ptr;
if (len == 0)
break;
}
} else {
memcpy(buf, s->buf_ptr, len);
buf += len;
s->buf_ptr += len;
size -= len;
}
}
if (size1 == size) {
if (s->error) return s->error;
if (s->eof_reached) return AVERROR_EOF;
}
return size1 - size;
}
int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size)
{
int len;
if(size<0)
return -1;
len = s->buf_end - s->buf_ptr;
if (len == 0) {
fill_buffer(s);
len = s->buf_end - s->buf_ptr;
}
if (len > size)
len = size;
memcpy(buf, s->buf_ptr, len);
s->buf_ptr += len;
if (!len) {
if (s->error) return s->error;
if (s->eof_reached) return AVERROR_EOF;
}
return len;
}
unsigned int avio_rl16(AVIOContext *s)
{
unsigned int val;
val = avio_r8(s);
val |= avio_r8(s) << 8;
return val;
}
unsigned int avio_rl24(AVIOContext *s)
{
unsigned int val;
val = avio_rl16(s);
val |= avio_r8(s) << 16;
return val;
}
unsigned int avio_rl32(AVIOContext *s)
{
unsigned int val;
val = avio_rl16(s);
val |= avio_rl16(s) << 16;
return val;
}
uint64_t avio_rl64(AVIOContext *s)
{
uint64_t val;
val = (uint64_t)avio_rl32(s);
val |= (uint64_t)avio_rl32(s) << 32;
return val;
}
unsigned int avio_rb16(AVIOContext *s)
{
unsigned int val;
val = avio_r8(s) << 8;
val |= avio_r8(s);
return val;
}
unsigned int avio_rb24(AVIOContext *s)
{
unsigned int val;
val = avio_rb16(s) << 8;
val |= avio_r8(s);
return val;
}
unsigned int avio_rb32(AVIOContext *s)
{
unsigned int val;
val = avio_rb16(s) << 16;
val |= avio_rb16(s);
return val;
}
#if FF_API_OLD_AVIO
char *get_strz(AVIOContext *s, char *buf, int maxlen)
{
avio_get_str(s, INT_MAX, buf, maxlen);
return buf;
}
#endif
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
{
int i = 0;
char c;
do {
c = avio_r8(s);
if (c && i < maxlen-1)
buf[i++] = c;
} while (c != '\n' && c);
buf[i] = 0;
return i;
}
int avio_get_str(AVIOContext *s, int maxlen, char *buf, int buflen)
{
int i;
// reserve 1 byte for terminating 0
buflen = FFMIN(buflen - 1, maxlen);
for (i = 0; i < buflen; i++)
if (!(buf[i] = avio_r8(s)))
return i + 1;
if (buflen)
buf[i] = 0;
for (; i < maxlen; i++)
if (!avio_r8(s))
return i + 1;
return maxlen;
}
#define GET_STR16(type, read) \
int avio_get_str16 ##type(AVIOContext *pb, int maxlen, char *buf, int buflen)\
{\
char* q = buf;\
int ret = 0;\
while (ret + 1 < maxlen) {\
uint8_t tmp;\
uint32_t ch;\
GET_UTF16(ch, (ret += 2) <= maxlen ? read(pb) : 0, break;)\
if (!ch)\
break;\
PUT_UTF8(ch, tmp, if (q - buf < buflen - 1) *q++ = tmp;)\
}\
*q = 0;\
return ret;\
}\
GET_STR16(le, avio_rl16)
GET_STR16(be, avio_rb16)
#undef GET_STR16
uint64_t avio_rb64(AVIOContext *s)
{
uint64_t val;
val = (uint64_t)avio_rb32(s) << 32;
val |= (uint64_t)avio_rb32(s);
return val;
}
uint64_t ff_get_v(AVIOContext *bc){
uint64_t val = 0;
int tmp;
do{
tmp = avio_r8(bc);
val= (val<<7) + (tmp&127);
}while(tmp&128);
return val;
}
int url_fdopen(AVIOContext **s, URLContext *h)
{
uint8_t *buffer;
int buffer_size, max_packet_size;
max_packet_size = url_get_max_packet_size(h);
if (max_packet_size) {
buffer_size = max_packet_size; /* no need to bufferize more than one packet */
} else {
buffer_size = IO_BUFFER_SIZE;
}
buffer = av_malloc(buffer_size);
if (!buffer)
return AVERROR(ENOMEM);
*s = av_mallocz(sizeof(AVIOContext));
if(!*s) {
av_free(buffer);
return AVERROR(ENOMEM);
}
if (ffio_init_context(*s, buffer, buffer_size,
(h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
url_read, url_write, url_seek) < 0) {
av_free(buffer);
av_freep(s);
return AVERROR(EIO);
}
(*s)->is_streamed = h->is_streamed;
(*s)->max_packet_size = max_packet_size;
if(h->prot) {
(*s)->read_pause = (int (*)(void *, int))h->prot->url_read_pause;
(*s)->read_seek = (int64_t (*)(void *, int, int64_t, int))h->prot->url_read_seek;
}
return 0;
}
int url_setbufsize(AVIOContext *s, int buf_size)
{
uint8_t *buffer;
buffer = av_malloc(buf_size);
if (!buffer)
return AVERROR(ENOMEM);
av_free(s->buffer);
s->buffer = buffer;
s->buffer_size = buf_size;
s->buf_ptr = buffer;
url_resetbuf(s, s->write_flag ? URL_WRONLY : URL_RDONLY);
return 0;
}
#if FF_API_URL_RESETBUF
int url_resetbuf(AVIOContext *s, int flags)
#else
static int url_resetbuf(AVIOContext *s, int flags)
#endif
{
#if FF_API_URL_RESETBUF
if (flags & URL_RDWR)
return AVERROR(EINVAL);
#else
assert(flags == URL_WRONLY || flags == URL_RDONLY);
#endif
if (flags & URL_WRONLY) {
s->buf_end = s->buffer + s->buffer_size;
s->write_flag = 1;
} else {
s->buf_end = s->buffer;
s->write_flag = 0;
}
return 0;
}
int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size)
{
int64_t buffer_start;
int buffer_size;
int overlap, new_size, alloc_size;
if (s->write_flag)
return AVERROR(EINVAL);
buffer_size = s->buf_end - s->buffer;
/* the buffers must touch or overlap */
if ((buffer_start = s->pos - buffer_size) > buf_size)
return AVERROR(EINVAL);
overlap = buf_size - buffer_start;
new_size = buf_size + buffer_size - overlap;
alloc_size = FFMAX(s->buffer_size, new_size);
if (alloc_size > buf_size)
if (!(buf = av_realloc(buf, alloc_size)))
return AVERROR(ENOMEM);
if (new_size > buf_size) {
memcpy(buf + buf_size, s->buffer + overlap, buffer_size - overlap);
buf_size = new_size;
}
av_free(s->buffer);
s->buf_ptr = s->buffer = buf;
s->buffer_size = alloc_size;
s->pos = buf_size;
s->buf_end = s->buf_ptr + buf_size;
s->eof_reached = 0;
s->must_flush = 0;
return 0;
}
int avio_open(AVIOContext **s, const char *filename, int flags)
{
URLContext *h;
int err;
err = url_open(&h, filename, flags);
if (err < 0)
return err;
err = url_fdopen(s, h);
if (err < 0) {
url_close(h);
return err;
}
return 0;
}
int avio_close(AVIOContext *s)
{
URLContext *h = s->opaque;
av_free(s->buffer);
av_free(s);
return url_close(h);
}
URLContext *url_fileno(AVIOContext *s)
{
return s->opaque;
}
#if CONFIG_MUXERS
int url_fprintf(AVIOContext *s, const char *fmt, ...)
{
va_list ap;
char buf[4096];
int ret;
va_start(ap, fmt);
ret = vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
avio_write(s, buf, strlen(buf));
return ret;
}
#endif //CONFIG_MUXERS
#if FF_API_OLD_AVIO
char *url_fgets(AVIOContext *s, char *buf, int buf_size)
{
int c;
char *q;
c = avio_r8(s);
if (s->eof_reached)
return NULL;
q = buf;
for(;;) {
if (s->eof_reached || c == '\n')
break;
if ((q - buf) < buf_size - 1)
*q++ = c;
c = avio_r8(s);
}
if (buf_size > 0)
*q = '\0';
return buf;
}
int url_fget_max_packet_size(AVIOContext *s)
{
return s->max_packet_size;
}
#endif
int av_url_read_fpause(AVIOContext *s, int pause)
{
if (!s->read_pause)
return AVERROR(ENOSYS);
return s->read_pause(s->opaque, pause);
}
int64_t av_url_read_fseek(AVIOContext *s, int stream_index,
int64_t timestamp, int flags)
{
URLContext *h = s->opaque;
int64_t ret;
if (!s->read_seek)
return AVERROR(ENOSYS);
ret = s->read_seek(h, stream_index, timestamp, flags);
if(ret >= 0) {
int64_t pos;
s->buf_ptr = s->buf_end; // Flush buffer
pos = s->seek(h, 0, SEEK_CUR);
if (pos >= 0)
s->pos = pos;
else if (pos != AVERROR(ENOSYS))
ret = pos;
}
return ret;
}
/* url_open_dyn_buf and url_close_dyn_buf are used in rtp.c to send a response
* back to the server even if CONFIG_MUXERS is false. */
#if CONFIG_MUXERS || CONFIG_NETWORK
/* buffer handling */
int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags)
{
int ret;
*s = av_mallocz(sizeof(AVIOContext));
if(!*s)
return AVERROR(ENOMEM);
ret = ffio_init_context(*s, buf, buf_size,
(flags & URL_WRONLY || flags & URL_RDWR),
NULL, NULL, NULL, NULL);
if(ret != 0)
av_freep(s);
return ret;
}
int url_close_buf(AVIOContext *s)
{
put_flush_packet(s);
return s->buf_ptr - s->buffer;
}
/* output in a dynamic buffer */
typedef struct DynBuffer {
int pos, size, allocated_size;
uint8_t *buffer;
int io_buffer_size;
uint8_t io_buffer[1];
} DynBuffer;
static int dyn_buf_write(void *opaque, uint8_t *buf, int buf_size)
{
DynBuffer *d = opaque;
unsigned new_size, new_allocated_size;
/* reallocate buffer if needed */
new_size = d->pos + buf_size;
new_allocated_size = d->allocated_size;
if(new_size < d->pos || new_size > INT_MAX/2)
return -1;
while (new_size > new_allocated_size) {
if (!new_allocated_size)
new_allocated_size = new_size;
else
new_allocated_size += new_allocated_size / 2 + 1;
}
if (new_allocated_size > d->allocated_size) {
d->buffer = av_realloc(d->buffer, new_allocated_size);
if(d->buffer == NULL)
return AVERROR(ENOMEM);
d->allocated_size = new_allocated_size;
}
memcpy(d->buffer + d->pos, buf, buf_size);
d->pos = new_size;
if (d->pos > d->size)
d->size = d->pos;
return buf_size;
}
static int dyn_packet_buf_write(void *opaque, uint8_t *buf, int buf_size)
{
unsigned char buf1[4];
int ret;
/* packetized write: output the header */
AV_WB32(buf1, buf_size);
ret= dyn_buf_write(opaque, buf1, 4);
if(ret < 0)
return ret;
/* then the data */
return dyn_buf_write(opaque, buf, buf_size);
}
static int64_t dyn_buf_seek(void *opaque, int64_t offset, int whence)
{
DynBuffer *d = opaque;
if (whence == SEEK_CUR)
offset += d->pos;
else if (whence == SEEK_END)
offset += d->size;
if (offset < 0 || offset > 0x7fffffffLL)
return -1;
d->pos = offset;
return 0;
}
static int url_open_dyn_buf_internal(AVIOContext **s, int max_packet_size)
{
DynBuffer *d;
int ret;
unsigned io_buffer_size = max_packet_size ? max_packet_size : 1024;
if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
return -1;
d = av_mallocz(sizeof(DynBuffer) + io_buffer_size);
if (!d)
return AVERROR(ENOMEM);
*s = av_mallocz(sizeof(AVIOContext));
if(!*s) {
av_free(d);
return AVERROR(ENOMEM);
}
d->io_buffer_size = io_buffer_size;
ret = ffio_init_context(*s, d->io_buffer, io_buffer_size,
1, d, NULL,
max_packet_size ? dyn_packet_buf_write : dyn_buf_write,
max_packet_size ? NULL : dyn_buf_seek);
if (ret == 0) {
(*s)->max_packet_size = max_packet_size;
} else {
av_free(d);
av_freep(s);
}
return ret;
}
int url_open_dyn_buf(AVIOContext **s)
{
return url_open_dyn_buf_internal(s, 0);
}
int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size)
{
if (max_packet_size <= 0)
return -1;
return url_open_dyn_buf_internal(s, max_packet_size);
}
int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
{
DynBuffer *d = s->opaque;
int size;
static const char padbuf[FF_INPUT_BUFFER_PADDING_SIZE] = {0};
int padding = 0;
/* don't attempt to pad fixed-size packet buffers */
if (!s->max_packet_size) {
avio_write(s, padbuf, sizeof(padbuf));
padding = FF_INPUT_BUFFER_PADDING_SIZE;
}
put_flush_packet(s);
*pbuffer = d->buffer;
size = d->size;
av_free(d);
av_free(s);
return size - padding;
}
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */
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