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/*
* import_ac3.c
*
* Copyright (C) Thomas Oestreich - June 2001
*
* 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.
*
*/
#define MOD_NAME "import_ac3.so"
#define MOD_VERSION "v0.3.2 (2002-02-15)"
#define MOD_CODEC "(audio) AC3"
#include "transcode.h"
static int verbose_flag = TC_QUIET;
static int capability_flag = TC_CAP_PCM | TC_CAP_AC3;
#define MOD_PRE ac3
#include "import_def.h"
#include "ac3scan.h"
char import_cmd_buf[TC_BUF_MAX];
static FILE *fd;
static int codec, syncf=0;
static int pseudo_frame_size=0, real_frame_size=0, effective_frame_size=0;
static int ac3_bytes_to_go=0;
/* ------------------------------------------------------------
*
* open stream
*
* ------------------------------------------------------------*/
MOD_open
{
long sret;
// audio only
if(param->flag != TC_AUDIO) return(TC_IMPORT_ERROR);
codec = vob->im_a_codec;
syncf = vob->sync;
switch(codec) {
case CODEC_AC3:
// produce a clean sequence of AC3 frames
sret = tc_snprintf(import_cmd_buf, TC_BUF_MAX,
"tcextract -a %d -i \"%s\" -x ac3 -d %d |"
" tcextract -t raw -x ac3 -d %d",
vob->a_track, vob->audio_in_file, vob->verbose, vob->verbose);
if (sret < 0)
return(TC_IMPORT_ERROR);
if(verbose_flag) tc_log_info(MOD_NAME, "AC3->AC3");
break;
case CODEC_PCM:
if(vob->a_codec_flag==CODEC_AC3) {
sret = tc_snprintf(import_cmd_buf, TC_BUF_MAX,
"tcextract -a %d -i \"%s\" -x ac3 -d %d |"
" tcdecode -x ac3 -d %d -s %f,%f,%f -A %d",
vob->a_track, vob->audio_in_file, vob->verbose,
vob->verbose, vob->ac3_gain[0], vob->ac3_gain[1],
vob->ac3_gain[2], vob->a52_mode);
if (sret < 0)
return(TC_IMPORT_ERROR);
if(verbose_flag) tc_log_info(MOD_NAME, "AC3->PCM");
}
break;
default:
tc_log_warn(MOD_NAME, "invalid import codec request 0x%x", codec);
return(TC_IMPORT_ERROR);
}
// print out
if(verbose_flag)
tc_log_info(MOD_NAME, "%s", import_cmd_buf);
// set to NULL if we handle read
param->fd = NULL;
// popen
if((fd = popen(import_cmd_buf, "r"))== NULL) {
tc_log_perror(MOD_NAME, "popen pcm stream");
return(TC_IMPORT_ERROR);
}
return(TC_IMPORT_OK);
}
/* ------------------------------------------------------------
*
* decode stream
*
* ------------------------------------------------------------*/
MOD_decode
{
int ac_bytes=0, ac_off=0;
int num_frames;
// audio only
if(param->flag != TC_AUDIO) return(TC_IMPORT_ERROR);
switch(codec) {
case CODEC_AC3:
// determine frame size at the very beginning of the stream
if (pseudo_frame_size == 0) {
if (ac3scan(fd, param->buffer, param->size, &ac_off, &ac_bytes,
&pseudo_frame_size, &real_frame_size, verbose) != 0)
return(TC_IMPORT_ERROR);
} else {
ac_off = 0;
ac_bytes = pseudo_frame_size;
}
// switch to entire frames:
// bytes_to_go is the difference between requested bytes and
// delivered bytes
//
// pseudo_frame_size = average bytes per audio frame
// real_frame_size = real AC3 frame size in bytes
num_frames = (ac_bytes + ac3_bytes_to_go) / real_frame_size;
effective_frame_size = num_frames * real_frame_size;
ac3_bytes_to_go = ac_bytes + ac3_bytes_to_go - effective_frame_size;
// return effective_frame_size as physical size of audio data
param->size = effective_frame_size;
if (verbose_flag & TC_STATS)
tc_log_info(MOD_NAME, "pseudo=%d, real=%d, frames=%d, effective=%d",
ac_bytes, real_frame_size, num_frames,
effective_frame_size);
// adjust
ac_bytes=effective_frame_size;
if(syncf>0) {
//dump an ac3 frame, instead of a pcm frame
ac_bytes = real_frame_size-ac_off;
param->size = real_frame_size;
--syncf;
}
break;
case CODEC_PCM:
//default:
ac_off = 0;
ac_bytes = param->size;
break;
default:
tc_log_warn(MOD_NAME, "invalid import codec request 0x%x", codec);
return(TC_IMPORT_ERROR);
}
if (fread(param->buffer+ac_off, ac_bytes-ac_off, 1, fd) !=1)
return(TC_IMPORT_ERROR);
return(TC_IMPORT_OK);
}
/* ------------------------------------------------------------
*
* close stream
*
* ------------------------------------------------------------*/
MOD_close
{
if(param->fd != NULL) pclose(param->fd);
return(TC_IMPORT_OK);
}
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