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FFmpeg/libavformat/aviobuf.c
Fabrice Bellard abac617591 renamed libav to libavformat 
Originally committed as revision 1276 to svn://svn.ffmpeg.org/ffmpeg/trunk
2002-11-25 19:07:40 +00:00

688 lines
16 KiB
C
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/*
* Buffered I/O for ffmpeg system
* Copyright (c) 2000,2001 Fabrice Bellard
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avformat.h"
#include <stdarg.h>
#define IO_BUFFER_SIZE 32768
int init_put_byte(ByteIOContext *s,
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, UINT8 *buf, int buf_size),
void (*write_packet)(void *opaque, UINT8 *buf, int buf_size),
int (*seek)(void *opaque, offset_t offset, int whence))
{
s->buffer = buffer;
s->buffer_size = buffer_size;
s->buf_ptr = buffer;
s->write_flag = write_flag;
if (!s->write_flag)
s->buf_end = buffer;
else
s->buf_end = buffer + buffer_size;
s->opaque = opaque;
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->is_streamed = 0;
s->max_packet_size = 0;
return 0;
}
static void flush_buffer(ByteIOContext *s)
{
if (s->buf_ptr > s->buffer) {
if (s->write_packet)
s->write_packet(s->opaque, s->buffer, s->buf_ptr - s->buffer);
s->pos += s->buf_ptr - s->buffer;
}
s->buf_ptr = s->buffer;
}
void put_byte(ByteIOContext *s, int b)
{
*(s->buf_ptr)++ = b;
if (s->buf_ptr >= s->buf_end)
flush_buffer(s);
}
void put_buffer(ByteIOContext *s, const unsigned char *buf, int size)
{
int len;
while (size > 0) {
len = (s->buf_end - s->buf_ptr);
if (len > size)
len = 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(ByteIOContext *s)
{
flush_buffer(s);
s->must_flush = 0;
}
offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence)
{
offset_t offset1;
if (whence != SEEK_CUR && whence != SEEK_SET)
return -EINVAL;
if (s->write_flag) {
if (whence == SEEK_CUR) {
offset1 = s->pos + (s->buf_ptr - s->buffer);
if (offset == 0)
return offset1;
offset += offset1;
}
offset1 = offset - s->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->seek)
return -EPIPE;
flush_buffer(s);
s->must_flush = 1;
s->buf_ptr = s->buffer;
s->seek(s->opaque, offset, SEEK_SET);
s->pos = offset;
}
} else {
if (whence == SEEK_CUR) {
offset1 = s->pos - (s->buf_end - s->buffer) + (s->buf_ptr - s->buffer);
if (offset == 0)
return offset1;
offset += offset1;
}
offset1 = offset - (s->pos - (s->buf_end - s->buffer));
if (offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {
/* can do the seek inside the buffer */
s->buf_ptr = s->buffer + offset1;
} else {
if (!s->seek)
return -EPIPE;
s->buf_ptr = s->buffer;
s->buf_end = s->buffer;
s->seek(s->opaque, offset, SEEK_SET);
s->pos = offset;
}
s->eof_reached = 0;
}
return offset;
}
void url_fskip(ByteIOContext *s, offset_t offset)
{
url_fseek(s, offset, SEEK_CUR);
}
offset_t url_ftell(ByteIOContext *s)
{
return url_fseek(s, 0, SEEK_CUR);
}
int url_feof(ByteIOContext *s)
{
return s->eof_reached;
}
void put_le32(ByteIOContext *s, unsigned int val)
{
put_byte(s, val);
put_byte(s, val >> 8);
put_byte(s, val >> 16);
put_byte(s, val >> 24);
}
void put_be32(ByteIOContext *s, unsigned int val)
{
put_byte(s, val >> 24);
put_byte(s, val >> 16);
put_byte(s, val >> 8);
put_byte(s, val);
}
/* IEEE format is assumed */
void put_be64_double(ByteIOContext *s, double val)
{
union {
double d;
UINT64 ull;
} u;
u.d = val;
put_be64(s, u.ull);
}
void put_strz(ByteIOContext *s, const char *str)
{
if (str)
put_buffer(s, (const unsigned char *) str, strlen(str) + 1);
else
put_byte(s, 0);
}
void put_le64(ByteIOContext *s, UINT64 val)
{
put_le32(s, (UINT32)(val & 0xffffffff));
put_le32(s, (UINT32)(val >> 32));
}
void put_be64(ByteIOContext *s, UINT64 val)
{
put_be32(s, (UINT32)(val >> 32));
put_be32(s, (UINT32)(val & 0xffffffff));
}
void put_le16(ByteIOContext *s, unsigned int val)
{
put_byte(s, val);
put_byte(s, val >> 8);
}
void put_be16(ByteIOContext *s, unsigned int val)
{
put_byte(s, val >> 8);
put_byte(s, val);
}
void put_tag(ByteIOContext *s, const char *tag)
{
while (*tag) {
put_byte(s, *tag++);
}
}
/* Input stream */
static void fill_buffer(ByteIOContext *s)
{
int len;
/* no need to do anything if EOF already reached */
if (s->eof_reached)
return;
len = s->read_packet(s->opaque, s->buffer, s->buffer_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;
} else {
s->pos += len;
s->buf_ptr = s->buffer;
s->buf_end = s->buffer + len;
}
}
/* NOTE: return 0 if EOF, so you cannot use it if EOF handling is
necessary */
/* XXX: put an inline version */
int get_byte(ByteIOContext *s)
{
if (s->buf_ptr < s->buf_end) {
return *s->buf_ptr++;
} else {
fill_buffer(s);
if (s->buf_ptr < s->buf_end)
return *s->buf_ptr++;
else
return 0;
}
}
/* NOTE: return URL_EOF (-1) if EOF */
int url_fgetc(ByteIOContext *s)
{
if (s->buf_ptr < s->buf_end) {
return *s->buf_ptr++;
} else {
fill_buffer(s);
if (s->buf_ptr < s->buf_end)
return *s->buf_ptr++;
else
return URL_EOF;
}
}
int get_buffer(ByteIOContext *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) {
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;
}
}
return size1 - size;
}
unsigned int get_le16(ByteIOContext *s)
{
unsigned int val;
val = get_byte(s);
val |= get_byte(s) << 8;
return val;
}
unsigned int get_le32(ByteIOContext *s)
{
unsigned int val;
val = get_byte(s);
val |= get_byte(s) << 8;
val |= get_byte(s) << 16;
val |= get_byte(s) << 24;
return val;
}
UINT64 get_le64(ByteIOContext *s)
{
UINT64 val;
val = (UINT64)get_le32(s);
val |= (UINT64)get_le32(s) << 32;
return val;
}
unsigned int get_be16(ByteIOContext *s)
{
unsigned int val;
val = get_byte(s) << 8;
val |= get_byte(s);
return val;
}
unsigned int get_be32(ByteIOContext *s)
{
unsigned int val;
val = get_byte(s) << 24;
val |= get_byte(s) << 16;
val |= get_byte(s) << 8;
val |= get_byte(s);
return val;
}
double get_be64_double(ByteIOContext *s)
{
union {
double d;
UINT64 ull;
} u;
u.ull = get_be64(s);
return u.d;
}
char *get_strz(ByteIOContext *s, char *buf, int maxlen)
{
int i = 0;
char c;
while ((c = get_byte(s))) {
if (i < maxlen-1)
buf[i++] = c;
}
buf[i] = 0; /* Ensure null terminated, but may be truncated */
return buf;
}
UINT64 get_be64(ByteIOContext *s)
{
UINT64 val;
val = (UINT64)get_be32(s) << 32;
val |= (UINT64)get_be32(s);
return val;
}
/* link with avio functions */
void url_write_packet(void *opaque, UINT8 *buf, int buf_size)
{
URLContext *h = opaque;
url_write(h, buf, buf_size);
}
int url_read_packet(void *opaque, UINT8 *buf, int buf_size)
{
URLContext *h = opaque;
return url_read(h, buf, buf_size);
}
int url_seek_packet(void *opaque, INT64 offset, int whence)
{
URLContext *h = opaque;
url_seek(h, offset, whence);
return 0;
}
int url_fdopen(ByteIOContext *s, URLContext *h)
{
UINT8 *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 -ENOMEM;
if (init_put_byte(s, buffer, buffer_size,
(h->flags & URL_WRONLY) != 0, h,
url_read_packet, url_write_packet, url_seek_packet) < 0) {
av_free(buffer);
return -EIO;
}
s->is_streamed = h->is_streamed;
s->max_packet_size = max_packet_size;
return 0;
}
/* XXX: must be called before any I/O */
int url_setbufsize(ByteIOContext *s, int buf_size)
{
UINT8 *buffer;
buffer = av_malloc(buf_size);
if (!buffer)
return -ENOMEM;
av_free(s->buffer);
s->buffer = buffer;
s->buffer_size = buf_size;
s->buf_ptr = buffer;
if (!s->write_flag)
s->buf_end = buffer;
else
s->buf_end = buffer + buf_size;
return 0;
}
/* NOTE: when opened as read/write, the buffers are only used for
reading */
int url_fopen(ByteIOContext *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 url_fclose(ByteIOContext *s)
{
URLContext *h = s->opaque;
av_free(s->buffer);
memset(s, 0, sizeof(ByteIOContext));
return url_close(h);
}
URLContext *url_fileno(ByteIOContext *s)
{
return s->opaque;
}
/* XXX: currently size is limited */
int url_fprintf(ByteIOContext *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);
put_buffer(s, buf, strlen(buf));
return ret;
}
/* note: unlike fgets, the EOL character is not returned and a whole
line is parsed. return NULL if first char read was EOF */
char *url_fgets(ByteIOContext *s, char *buf, int buf_size)
{
int c;
char *q;
c = url_fgetc(s);
if (c == EOF)
return NULL;
q = buf;
for(;;) {
if (c == EOF || c == '\n')
break;
if ((q - buf) < buf_size - 1)
*q++ = c;
c = url_fgetc(s);
}
if (buf_size > 0)
*q = '\0';
return buf;
}
/*
* Return the maximum packet size associated to packetized buffered file
* handle. If the file is not packetized (stream like http or file on
* disk), then 0 is returned.
*
* @param h buffered file handle
* @return maximum packet size in bytes
*/
int url_fget_max_packet_size(ByteIOContext *s)
{
return s->max_packet_size;
}
/* buffer handling */
int url_open_buf(ByteIOContext *s, UINT8 *buf, int buf_size, int flags)
{
return init_put_byte(s, buf, buf_size,
(flags & URL_WRONLY) != 0, NULL, NULL, NULL, NULL);
}
/* return the written or read size */
int url_close_buf(ByteIOContext *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 *buffer;
int io_buffer_size;
UINT8 io_buffer[1];
} DynBuffer;
static void dyn_buf_write(void *opaque, UINT8 *buf, int buf_size)
{
DynBuffer *d = opaque;
int new_size, new_allocated_size;
UINT8 *new_buffer;
/* reallocate buffer if needed */
new_size = d->pos + buf_size;
new_allocated_size = d->allocated_size;
while (new_size > new_allocated_size) {
if (!new_allocated_size)
new_allocated_size = new_size;
else
new_allocated_size = (new_allocated_size * 3) / 2 + 1;
}
if (new_allocated_size > d->allocated_size) {
new_buffer = av_malloc(new_allocated_size);
if (!new_buffer)
return;
memcpy(new_buffer, d->buffer, d->size);
av_free(d->buffer);
d->buffer = new_buffer;
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;
}
static void dyn_packet_buf_write(void *opaque, UINT8 *buf, int buf_size)
{
unsigned char buf1[4];
/* packetized write: output the header */
buf1[0] = (buf_size >> 24);
buf1[1] = (buf_size >> 16);
buf1[2] = (buf_size >> 8);
buf1[3] = (buf_size);
dyn_buf_write(opaque, buf1, 4);
/* then the data */
dyn_buf_write(opaque, buf, buf_size);
}
static int dyn_buf_seek(void *opaque, offset_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(ByteIOContext *s, int max_packet_size)
{
DynBuffer *d;
int io_buffer_size, ret;
if (max_packet_size)
io_buffer_size = max_packet_size;
else
io_buffer_size = 1024;
d = av_malloc(sizeof(DynBuffer) + io_buffer_size);
if (!d)
return -1;
d->io_buffer_size = io_buffer_size;
d->buffer = NULL;
d->pos = 0;
d->size = 0;
d->allocated_size = 0;
ret = init_put_byte(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;
}
return ret;
}
/*
* Open a write only memory stream.
*
* @param s new IO context
* @return zero if no error.
*/
int url_open_dyn_buf(ByteIOContext *s)
{
return url_open_dyn_buf_internal(s, 0);
}
/*
* Open a write only packetized memory stream with a maximum packet
* size of 'max_packet_size'. The stream is stored in a memory buffer
* with a big endian 4 byte header giving the packet size in bytes.
*
* @param s new IO context
* @param max_packet_size maximum packet size (must be > 0)
* @return zero if no error.
*/
int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size)
{
if (max_packet_size <= 0)
return -1;
return url_open_dyn_buf_internal(s, max_packet_size);
}
/*
* Return the written size and a pointer to the buffer. The buffer
* must be freed with av_free().
* @param s IO context
* @param pointer to a byte buffer
* @return the length of the byte buffer
*/
int url_close_dyn_buf(ByteIOContext *s, UINT8 **pbuffer)
{
DynBuffer *d = s->opaque;
int size;
put_flush_packet(s);
*pbuffer = d->buffer;
size = d->size;
av_free(d);
return size;
}
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