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ffmpeg/libav/aviobuf.c

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/*
* Buffered I/O for ffmpeg system
* Copyright (c) 2000,2001 Gerard Lantau
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "avformat.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->packet_size = 1;
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, 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->eof_reached = 0;
s->seek(s->opaque, offset, SEEK_SET);
s->pos = offset;
}
}
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);
}
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, char *tag)
{
while (*tag) {
put_byte(s, *tag++);
}
}
/* Input stream */
static void fill_buffer(ByteIOContext *s)
{
int len;
len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
s->pos += len;
s->buf_ptr = s->buffer;
s->buf_end = s->buffer + len;
if (len == 0) {
s->eof_reached = 1;
}
}
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;
}
}
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;
}
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;
buffer_size = (IO_BUFFER_SIZE / h->packet_size) * h->packet_size;
buffer = 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) {
free(buffer);
return -EIO;
}
s->is_streamed = h->is_streamed;
s->packet_size = h->packet_size;
return 0;
}
/* XXX: must be called before any I/O */
int url_setbufsize(ByteIOContext *s, int buf_size)
{
UINT8 *buffer;
buffer = malloc(buf_size);
if (!buffer)
return -ENOMEM;
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;
}
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;
free(s->buffer);
memset(s, 0, sizeof(ByteIOContext));
return url_close(h);
}
URLContext *url_fileno(ByteIOContext *s)
{
return s->opaque;
}
/* 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)
{
return s->buf_ptr - s->buffer;
}
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