ref: d74c851febda06d0cc783adc8dded6c971b7d556
dir: /libcelt/header.c/
/* Copyright (c) 2007 CSIRO
Copyright (c) 2007-2009 Xiph.Org Foundation
Written by Jean-Marc Valin */
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "celt_header.h"
#include "os_support.h"
#include "modes.h"
static celt_uint32
_le_32 (celt_uint32 i)
{
celt_uint32 ret=i;
#if !defined(__LITTLE_ENDIAN__) && ( defined(WORDS_BIGENDIAN) || defined(__BIG_ENDIAN__) )
ret = (i>>24);
ret += (i>>8) & 0x0000ff00;
ret += (i<<8) & 0x00ff0000;
ret += (i<<24);
#endif
return ret;
}
int celt_header_init(CELTHeader *header, const CELTMode *m, int channels)
{
if (header==NULL)
return CELT_BAD_ARG;
CELT_COPY(header->codec_id, "CELT ", 8);
CELT_COPY(header->codec_version, "experimental ", 20);
celt_mode_info(m, CELT_GET_BITSTREAM_VERSION, &header->version_id);
header->header_size = 56;
header->sample_rate = m->Fs;
header->nb_channels = channels;
/*FIXME: This won't work for variable frame size */
header->frame_size = m->shortMdctSize*m->nbShortMdcts;
header->overlap = m->overlap;
header->bytes_per_packet = -1;
header->extra_headers = 0;
return CELT_OK;
}
int celt_header_to_packet(const CELTHeader *header, unsigned char *packet, celt_uint32 size)
{
celt_int32 * h;
if ((size < 56) || (header==NULL) || (packet==NULL))
return CELT_BAD_ARG; /* FAIL */
CELT_MEMSET(packet, 0, sizeof(*header));
/* FIXME: Do it in an alignment-safe manner */
/* Copy ident and version */
CELT_COPY(packet, (unsigned char*)header, 28);
/* Copy the int32 fields */
h = (celt_int32*)(packet+28);
*h++ = _le_32 (header->version_id);
*h++ = _le_32 (header->header_size);
*h++ = _le_32 (header->sample_rate);
*h++ = _le_32 (header->nb_channels);
*h++ = _le_32 (header->frame_size);
*h++ = _le_32 (header->overlap);
*h++ = _le_32 (header->bytes_per_packet);
*h = _le_32 (header->extra_headers);
return sizeof(*header);
}
int celt_header_from_packet(const unsigned char *packet, celt_uint32 size, CELTHeader *header)
{
celt_int32 * h;
if ((size < 56) || (header==NULL) || (packet==NULL))
return CELT_BAD_ARG; /* FAIL */
CELT_MEMSET((unsigned char*)header, 0, sizeof(*header));
/* FIXME: Do it in an alignment-safe manner */
/* Copy ident and version */
CELT_COPY((unsigned char*)header, packet, 28);
/* Copy the int32 fields */
h = (celt_int32*)(packet+28);
header->version_id = _le_32(*h++);
header->header_size = _le_32(*h++);
header->sample_rate = _le_32(*h++);
header->nb_channels = _le_32(*h++);
header->frame_size = _le_32(*h++);
header->overlap = _le_32(*h++);
header->bytes_per_packet = _le_32(*h++);
header->extra_headers = _le_32(*h);
return sizeof(*header);
}