winamp/Src/Plugins/Input/in_avi/win32_avi_reader.cpp

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2024-09-24 12:54:57 +00:00
#include "win32_avi_reader.h"
#include <strsafe.h>
const int _BUFFER_SIZE_ = 16384;
AVIReaderWin32::AVIReaderWin32()
{
hFile = 0;
_ring_buffer.reserve( _BUFFER_SIZE_ );
end_of_file = false;
position.QuadPart = 0;
local_filename = 0;
}
AVIReaderWin32::~AVIReaderWin32()
{
free( local_filename );
}
void AVIReaderWin32::Close()
{
if ( hFile && hFile != INVALID_HANDLE_VALUE )
{
//CancelIo(hFile);
CloseHandle( hFile );
}
}
uint64_t AVIReaderWin32::GetContentLength()
{
LARGE_INTEGER position;
position.QuadPart = 0;
position.LowPart = GetFileSize( hFile, (LPDWORD)&position.HighPart );
if ( position.LowPart == INVALID_FILE_SIZE && GetLastError() != NO_ERROR )
return 0;
else
return position.QuadPart;
}
void AVIReaderWin32::GetFilename( wchar_t *fn, size_t len )
{
StringCchCopyW( fn, len, local_filename );
}
int AVIReaderWin32::Open( const wchar_t *filename )
{
free( local_filename );
local_filename = _wcsdup( filename );
hFile = CreateFile( filename, GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, 0 );
if ( hFile == INVALID_HANDLE_VALUE )
return nsavi::READ_NOT_FOUND;
return nsavi::READ_OK;
}
/* used by RingBuffer::fill() */
size_t AVIReaderWin32::Read( void *dest, size_t len )
{
// TODO: use overlapped I/O so can we wait on the read simultaneously with the killswitch and seek_event
DWORD bytes_read = 0;
if ( ReadFile( hFile, dest, (DWORD)len, &bytes_read, NULL ) && bytes_read != len )
end_of_file = true;
return bytes_read;
}
int AVIReaderWin32::Read( void *p_read_buffer, uint32_t read_length, uint32_t *bytes_read )
{
if ( end_of_file && _ring_buffer.empty() )
return nsavi::READ_EOF;
size_t total_bytes_read = 0;
while ( read_length && !( end_of_file && _ring_buffer.empty() ) )
{
// read what we can from the buffer
size_t bytes_read = _ring_buffer.read( p_read_buffer, read_length );
p_read_buffer = (uint8_t *)p_read_buffer + bytes_read;
read_length -= (uint32_t)bytes_read;
total_bytes_read += bytes_read;
position.QuadPart += bytes_read;
if ( read_length > _BUFFER_SIZE_ )
{
// read directly from the file if we have a large read
bytes_read = Read( p_read_buffer, read_length );
p_read_buffer = (uint8_t *)p_read_buffer + bytes_read;
read_length -= (uint32_t)bytes_read;
total_bytes_read += bytes_read;
position.QuadPart += bytes_read;
}
else
{
// refill buffer if necessary
_ring_buffer.fill( this, _BUFFER_SIZE_ );
}
}
*bytes_read = (uint32_t)total_bytes_read;
return nsavi::READ_OK;
}
int AVIReaderWin32::Peek( void *read_buffer, uint32_t read_length, uint32_t *bytes_read )
{
if ( end_of_file && _ring_buffer.empty() )
return nsavi::READ_EOF;
// refill buffer if necessary
if ( _ring_buffer.size() < read_length )
_ring_buffer.fill( this, _BUFFER_SIZE_ );
*bytes_read = (uint32_t)_ring_buffer.peek( read_buffer, read_length );
return nsavi::READ_OK;
}
static LONGLONG Seek64( HANDLE hf, __int64 distance, DWORD MoveMethod )
{
LARGE_INTEGER li;
li.QuadPart = distance;
li.LowPart = SetFilePointer( hf, li.LowPart, &li.HighPart, MoveMethod );
if ( li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR )
{
li.QuadPart = -1;
}
return li.QuadPart;
}
int AVIReaderWin32::Seek( uint64_t new_position )
{
_ring_buffer.clear();
position.QuadPart = Seek64( hFile, new_position, SEEK_SET );
end_of_file = ( position.QuadPart != new_position );
return nsavi::READ_OK;
}
uint64_t AVIReaderWin32::Tell()
{
return position.QuadPart;
}
int AVIReaderWin32::Skip( uint32_t skip_bytes )
{
if ( end_of_file && _ring_buffer.empty() )
return nsavi::READ_EOF;
if ( skip_bytes < _ring_buffer.size() )
{
_ring_buffer.advance( skip_bytes );
position.QuadPart += skip_bytes;
return nsavi::READ_OK;
}
else
{
return Seek( position.QuadPart + skip_bytes );
}
}
void AVIReaderWin32::OverlappedHint( uint32_t read_length )
{
if ( read_length > _ring_buffer.size() )
_ring_buffer.fill( this, _BUFFER_SIZE_ );
}