FFmpeg/libavformat/aviobuf.c
Panagiotis Issaris a8c5ab2707 Move aviobuf.c comments to avio.h. By moving the aviobuf.c comments to avio.h,
these comments can be extracted by Doxygen by only accessing the installed
headers.

Originally committed as revision 8258 to svn://svn.ffmpeg.org/ffmpeg/trunk
2007-03-05 13:55:45 +00:00

756 lines
18 KiB
C

/*
* 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 "avformat.h"
#include "avio.h"
#include <stdarg.h>
#define IO_BUFFER_SIZE 32768
static void fill_buffer(ByteIOContext *s);
int init_put_byte(ByteIOContext *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),
offset_t (*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->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;
}
return 0;
}
static void flush_buffer(ByteIOContext *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 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;
offset_t 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 && !s->write_flag &&
offset1 >= 0 && offset1 < (s->buf_end - s->buffer) + (1<<16)){
while(s->pos < offset && !s->eof_reached)
fill_buffer(s);
s->buf_ptr = s->buf_end + offset - s->pos;
} else {
offset_t res = AVERROR(EPIPE);
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
if (s->write_flag) {
flush_buffer(s);
s->must_flush = 1;
} else
#endif /* defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK) */
{
s->buf_end = s->buffer;
}
s->buf_ptr = s->buffer;
if (!s->seek || (res = s->seek(s->opaque, offset, SEEK_SET)) < 0)
return res;
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);
}
offset_t url_fsize(ByteIOContext *s)
{
offset_t size;
if (!s->seek)
return AVERROR(EPIPE);
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;
}
int url_feof(ByteIOContext *s)
{
return s->eof_reached;
}
int url_ferror(ByteIOContext *s)
{
return s->error;
}
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_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_t val)
{
put_le32(s, (uint32_t)(val & 0xffffffff));
put_le32(s, (uint32_t)(val >> 32));
}
void put_be64(ByteIOContext *s, uint64_t val)
{
put_be32(s, (uint32_t)(val >> 32));
put_be32(s, (uint32_t)(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_le24(ByteIOContext *s, unsigned int val)
{
put_le16(s, val & 0xffff);
put_byte(s, val >> 16);
}
void put_be24(ByteIOContext *s, unsigned int val)
{
put_be16(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;
if(s->update_checksum){
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;
}
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;
if(len<0)
s->error= len;
} else {
s->pos += len;
s->buf_ptr = s->buffer;
s->buf_end = s->buffer + len;
}
}
unsigned long get_checksum(ByteIOContext *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(ByteIOContext *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 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 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) {
if(size > s->buffer_size && !s->update_checksum){
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;
}
}
return size1 - size;
}
int get_partial_buffer(ByteIOContext *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;
return len;
}
unsigned int get_le16(ByteIOContext *s)
{
unsigned int val;
val = get_byte(s);
val |= get_byte(s) << 8;
return val;
}
unsigned int get_le24(ByteIOContext *s)
{
unsigned int val;
val = get_le16(s);
val |= get_byte(s) << 16;
return val;
}
unsigned int get_le32(ByteIOContext *s)
{
unsigned int val;
val = get_le16(s);
val |= get_le16(s) << 16;
return val;
}
uint64_t get_le64(ByteIOContext *s)
{
uint64_t val;
val = (uint64_t)get_le32(s);
val |= (uint64_t)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_be24(ByteIOContext *s)
{
unsigned int val;
val = get_be16(s) << 8;
val |= get_byte(s);
return val;
}
unsigned int get_be32(ByteIOContext *s)
{
unsigned int val;
val = get_be16(s) << 16;
val |= get_be16(s);
return val;
}
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_t get_be64(ByteIOContext *s)
{
uint64_t val;
val = (uint64_t)get_be32(s) << 32;
val |= (uint64_t)get_be32(s);
return val;
}
/* link with avio functions */
#ifdef CONFIG_MUXERS
static int url_write_packet(void *opaque, uint8_t *buf, int buf_size)
{
URLContext *h = opaque;
return url_write(h, buf, buf_size);
}
#else
#define url_write_packet NULL
#endif //CONFIG_MUXERS
static int url_read_packet(void *opaque, uint8_t *buf, int buf_size)
{
URLContext *h = opaque;
return url_read(h, buf, buf_size);
}
static offset_t url_seek_packet(void *opaque, offset_t offset, int whence)
{
URLContext *h = opaque;
return url_seek(h, offset, whence);
//return 0;
}
int url_fdopen(ByteIOContext *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);
if (init_put_byte(s, buffer, buffer_size,
(h->flags & URL_WRONLY || h->flags & URL_RDWR), h,
url_read_packet, url_write_packet, url_seek_packet) < 0) {
av_free(buffer);
return AVERROR_IO;
}
s->is_streamed = h->is_streamed;
s->max_packet_size = max_packet_size;
return 0;
}
int url_setbufsize(ByteIOContext *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;
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;
av_free(s->buffer);
memset(s, 0, sizeof(ByteIOContext));
return url_close(h);
}
URLContext *url_fileno(ByteIOContext *s)
{
return s->opaque;
}
#ifdef CONFIG_MUXERS
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;
}
#endif //CONFIG_MUXERS
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;
}
int url_fget_max_packet_size(ByteIOContext *s)
{
return s->max_packet_size;
}
/* 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 not set. */
#if defined(CONFIG_MUXERS) || defined(CONFIG_NETWORK)
/* buffer handling */
int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags)
{
return init_put_byte(s, buf, buf_size,
(flags & URL_WRONLY || flags & URL_RDWR),
NULL, NULL, NULL, NULL);
}
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_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;
int 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 -1234;
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 */
buf1[0] = (buf_size >> 24);
buf1[1] = (buf_size >> 16);
buf1[2] = (buf_size >> 8);
buf1[3] = (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 offset_t 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;
if(sizeof(DynBuffer) + io_buffer_size < io_buffer_size)
return -1;
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;
}
int url_open_dyn_buf(ByteIOContext *s)
{
return url_open_dyn_buf_internal(s, 0);
}
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);
}
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer)
{
DynBuffer *d = s->opaque;
int size;
put_flush_packet(s);
*pbuffer = d->buffer;
size = d->size;
av_free(d);
return size;
}
#endif /* CONFIG_MUXERS || CONFIG_NETWORK */