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/*****************************************************************
* gmerlin-avdecoder - a general purpose multimedia decoding library
*
* Copyright (c) 2001 - 2012 Members of the Gmerlin project
* gmerlin-general@lists.sourceforge.net
* http://gmerlin.sourceforge.net
*
* 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, see <http://www.gnu.org/licenses/>.
* *****************************************************************/
#include <string.h>
#include <avdec_private.h>
#include <stdio.h>
#include <xing.h>
#include <mpa_header.h>
#define GET_INT32BE(b) \
(i = (b[0] << 24) | (b[1] << 16) | b[2] << 8 | b[3], b += 4, i)
int bgav_xing_header_probe(unsigned char *buf)
{
bgav_mpa_header_t h;
uint8_t * ptr;
memset(&h, 0, sizeof(h));
if(!bgav_mpa_header_decode(&h, buf))
return 0;
ptr = buf + 4 + (h.has_crc * 2) + h.side_info_size;
if(!memcmp(ptr, "Xing", 4))
return 1;
return 0;
}
int bgav_mp3_info_header_probe(unsigned char *buf)
{
bgav_mpa_header_t h;
uint8_t * ptr;
memset(&h, 0, sizeof(h));
if(!bgav_mpa_header_decode(&h, buf))
return 0;
ptr = buf + 4 + (h.has_crc * 2) + h.side_info_size;
if(!memcmp(ptr, "Info", 4))
return 1;
return 0;
}
int bgav_xing_header_read(bgav_xing_header_t * xing, unsigned char *buf)
{
int i;
bgav_mpa_header_t h;
memset(xing, 0, sizeof(*xing));
memset(&h, 0, sizeof(h));
if(!bgav_mpa_header_decode(&h, buf))
return 0;
buf += 4 + (h.has_crc * 2) + h.side_info_size;
if (strncmp((char*)buf, "Xing", 4))
return 0;
buf += 4;
xing->flags = GET_INT32BE(buf);
if (xing->flags & FRAMES_FLAG)
xing->frames = GET_INT32BE(buf);
if (xing->frames < 1)
xing->frames = 1;
if (xing->flags & BYTES_FLAG)
xing->bytes = GET_INT32BE(buf);
if (xing->flags & TOC_FLAG)
{
for (i = 0; i < 100; i++)
xing->toc[i] = buf[i];
buf += 100;
}
return 1;
}
#define CLAMP(i, min, max) i<min?min:(i>max?max:i)
#define MIN(i1,i2) i1<i2?i1:i2
int64_t bgav_xing_get_seek_position(bgav_xing_header_t * xing, float percent)
{
/* interpolate in TOC to get file seek point in bytes */
int a, seekpoint;
float fa, fb, fx;
percent = CLAMP(percent, 0.0, 100.0);
a = MIN(percent, 99);
fa = xing->toc[a];
if (a < 99)
fb = xing->toc[a + 1];
else
fb = 256;
fx = fa + (fb - fa) * (percent - a);
seekpoint = (1.0f / 256.0f) * fx * xing->bytes;
return seekpoint;
}
void bgav_xing_header_dump(bgav_xing_header_t * xing)
{
int i, j;
bgav_dprintf( "Xing header:\n");
bgav_dprintf( "Flags: %08x, ", xing->flags);
if(xing->flags & FRAMES_FLAG)
bgav_dprintf( "FRAMES_FLAG ");
if(xing->flags & BYTES_FLAG)
bgav_dprintf( "BYTES_FLAG ");
if(xing->flags & TOC_FLAG)
bgav_dprintf( "TOC_FLAG ");
if(xing->flags & VBR_SCALE_FLAG)
bgav_dprintf( "VBR_SCALE_FLAG ");
bgav_dprintf( "\nFrames: %u\n", xing->frames);
bgav_dprintf( "Bytes: %u\n", xing->bytes);
bgav_dprintf( "TOC:\n");
for(i = 0; i < 10; i++)
{
for(j = 0; j < 10; j++)
{
bgav_dprintf( "%02x ", xing->toc[i*10+j]);
}
bgav_dprintf( "\n");
}
}
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