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/*
* a52_decore.c
*
* Copyright (C) Thomas Oestreich - June 2001
* changes by Joerg Sauer <js-mail@gmx.net> for liba52-0.7.3
*
* This file is part of transcode, a video stream processing tool
*
* transcode 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, or (at your option)
* any later version.
*
* transcode 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include "transcode.h"
#include "tcinfo.h"
#include "libtc/libtc.h"
#include <limits.h>
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#else
# ifdef OS_DARWIN
# include "libdldarwin/dlfcn.h"
# endif
#endif
#include <a52dec/a52.h>
#include <a52dec/mm_accel.h>
#include "magic.h"
#define FRAME_SIZE 3840
#define HEADER_LEN 8
#define A52_BLOCKS 6
static inline int16_t convert (int32_t i)
{
if (i > 0x43c07fff)
return 32767;
else if (i < 0x43bf8000)
return -32768;
else
return i - 0x43c00000;
}
static void float2s16_2 (float * _f, int16_t * s16)
{
int i;
int32_t * f = (int32_t *) _f;
//interleave l/r channels
for (i = 0; i < 256; i++) {
s16[2*i] = convert (f[i]);
s16[2*i+1] = convert (f[i+256]);
}
}
static void float2s16 (float * _f, int16_t * s16)
{
int i;
int32_t * f = (int32_t *) _f;
for (i = 0; i < 256*A52_BLOCKS; i++) s16[i] = convert (f[i]);
}
static unsigned char buf[FRAME_SIZE];
int a52_decore(decode_t *decode); /* avoid a missing-prototype warning */
int a52_decore(decode_t *decode) {
int i, s=0, pcm_size, frame_size;
int k, n, bytes_read, bytes_wrote, sample_rate, bit_rate, flags;
unsigned short sync_word = 0;
int pass_through = decode->format==TC_CODEC_RAW?1:0;
a52_state_t *state;
sample_t level=1, bias=384;
sample_t *samples;
int chans = -1;
int16_t pcm_buf[256 * A52_BLOCKS];
uint32_t accel = MM_ACCEL_DJBFFT;
#ifdef HAVE_ASM_MMX
if (ac_cpuinfo() & AC_MMX)
accel |= MM_ACCEL_X86_MMX;
#endif
#ifdef HAVE_ASM_3DNOW
if (ac_cpuinfo() & AC_3DNOW)
accel |= MM_ACCEL_X86_3DNOW;
#endif
state = a52_init(accel);
n=0;
for (;;) {
// check for next AC3 sync bytes
k=0;
memset(buf, 0, HEADER_LEN);
s=0;
sync_word = 0;
bytes_read = 0;
bytes_wrote = 0;
for (;;) {
if (tc_pread(decode->fd_in, &buf[s], 1) !=1) {
//ac3 sync frame scan failed
return(-1);
}
sync_word = (sync_word << 8) + (unsigned char) buf[s];
s = (s+1)%2;
++k;
if(sync_word == 0x0b77) break;
if(k>(1<<20)) {
tc_log_error(__FILE__, "no AC3 sync frame found within 1024 kB of stream");
return(-1);
}
}
// found, read rest of frame header
buf[0] = (sync_word >> 8) & 0xff;
buf[1] = (sync_word) & 0xff;
bytes_read=tc_pread(decode->fd_in, &buf[2], HEADER_LEN-2);
if(bytes_read< HEADER_LEN-2) {
if(decode->verbose & TC_DEBUG)
tc_log_msg(__FILE__, "read error (%d/%d)", bytes_read, HEADER_LEN-2);
return(-1);
}
// FIXME:
// save header
// ac_memcpy(header, &buf[2], 5);
// valid AC3 frame?
frame_size = a52_syncinfo(buf, &flags, &sample_rate, &bit_rate);
if(frame_size==0 || frame_size>= FRAME_SIZE) {
tc_log_msg(__FILE__, "frame size = %d (%d %d)", frame_size, sample_rate, bit_rate);
goto skip_frame;
}
// read the rest of the frame
if((bytes_read=tc_pread(decode->fd_in, &buf[HEADER_LEN], frame_size-HEADER_LEN)) < frame_size-HEADER_LEN) {
if(decode->verbose & TC_DEBUG)
tc_log_msg(__FILE__, "read error (%d/%d)", bytes_read, frame_size-HEADER_LEN);
return(-1);
}
// decoder start
flags = (decode->a52_mode & TC_A52_DOLBY_OFF) ? A52_STEREO:A52_DOLBY;
flags = (decode->a52_mode & TC_A52_DEMUX) ? (A52_3F2R | A52_LFE) : flags;
a52_frame(state, buf, &flags, &level, bias);
if(decode->a52_mode & TC_A52_DRC_OFF) a52_dynrng (state, NULL, NULL);
flags &= A52_CHANNEL_MASK | A52_LFE;
if (flags & A52_LFE)
chans = 6;
else if (flags & 1) /* center channel */
chans = 5;
else switch (flags) {
case A52_2F2R:
chans = 4;
break;
case A52_CHANNEL:
case A52_STEREO:
case A52_DOLBY:
chans = 2;
break;
default:
return 1;
}
// decode frame
if (!pass_through) {
for(i=0; i<A52_BLOCKS; ++i) {
a52_block(state);
// output pcm data
samples = a52_samples(state);
pcm_size = 256 * sizeof (int16_t)*chans;
//tc_log_msg(__FILE__, "write (%d) bytes", pcm_size);
(decode->a52_mode & TC_A52_DEMUX) ? float2s16((float *)samples, (int16_t *)&pcm_buf) : float2s16_2((float *)samples, (int16_t *)&pcm_buf);
if((bytes_wrote=tc_pwrite(decode->fd_out, (char*) pcm_buf, pcm_size)) < pcm_size) {
if(decode->verbose & TC_DEBUG)
tc_log_error(__FILE__, "write error (%d/%d)", bytes_wrote, pcm_size);
return(-1);
}
} //end pcm data output
} else {
// pass through
for(i=0; i<A52_BLOCKS; ++i) {
a52_block(state);
// output pcm data
samples = a52_samples(state);
pcm_size = 256 * sizeof (int16_t)*chans;
//tc_log_msg(__FILE__, "write (%d) bytes", pcm_size);
(decode->a52_mode & TC_A52_DEMUX) ? float2s16((float *)samples, (int16_t *)&pcm_buf) : float2s16_2((float *)samples, (int16_t *)&pcm_buf);
} //end pcm data output
if((bytes_wrote=tc_pwrite(decode->fd_out, buf, bytes_read+HEADER_LEN)) < bytes_read+HEADER_LEN) {
if(decode->verbose & TC_DEBUG)
tc_log_error(__FILE__, "write error (%d/%d)", bytes_wrote, bytes_read+HEADER_LEN);
return(-1);
}
}
skip_frame:
continue;
} //end frame processing
// should not get here
return 0;
}
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