You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

259 lines
6.3 KiB

/*
* export_mp2.c
*
* Copyright (C) Simone Karin Lehmann, June 2004, based on export_ac3 by Daniel Pittman
* Copyright (C) Daniel Pittman, 2003, based on export_ogg.c which was:
* Copyright (C) Tilmann Bitterberg, July 2002
*
* 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.
*
*/
/* Usage:
This module processes audio streams only. There are no compile time depencies.
At run time, sox and ffmpeg must be present.
This module lets you encode audio to MPEG 1 Layer 2 audio aka mp2. It uses the
ffmpeg encoder and therefor it's very fast. Just do
-y <video_module>,mp2
Additionaly this module can change the speed of the audio stream by a factor the
user can specify. You need sox do do this. Use the module the follwing way
-y <video_module>,mp2=speed=N
where N is an unsigned float. N < 1.0 will slow down audio (meaning playing time will
increase) whereas N > 1.0 will speed up audio (meaning playing time will decrease)
The pitch of the audio is not corrected. E.g. to speed up audio by 25/23.976 (this
is used to convert NTSC film material to PAL) use
-y <video_module>,mp2=speed=1.0427093
*/
#define MOD_NAME "export_mp2.so"
#define MOD_VERSION "v0.2.1 (2004-08-06)"
#define MOD_CODEC "(audio) MPEG 1/2"
#include "transcode.h"
#include "libtc/optstr.h"
#include <stdio.h>
#include <unistd.h>
static int verbose_flag=TC_QUIET;
static int capability_flag=TC_CAP_PCM;
#define MOD_PRE mp2
#include "export_def.h"
static FILE *pFile = NULL;
static double speed = 0.0;
static inline int p_write (char *buf, size_t len)
{
size_t n = 0;
size_t r = 0;
int fd = fileno (pFile);
while (r < len)
{
if ((n = write (fd, buf + r, len - r)) < 0)
return n;
r += n;
}
return r;
}
/* ------------------------------------------------------------
*
* open codec
*
* ------------------------------------------------------------*/
MOD_open
{
int result, srate;
/* check for ffmpeg */
if (tc_test_program("ffmpeg") != 0) return (TC_EXPORT_ERROR);
if (param->flag == TC_AUDIO) {
char buf [PATH_MAX];
char out_fname [PATH_MAX];
char *ptr = buf;
strlcpy(out_fname, vob->audio_out_file, sizeof(out_fname));
if (strcmp(vob->audio_out_file, vob->video_out_file) == 0)
strlcat(out_fname, ".mpa", sizeof(out_fname));
if (vob->mp3bitrate == 0) {
tc_log_warn (MOD_NAME, "Audio bitrate 0 is not valid, cannot cope.");
return(TC_EXPORT_ERROR);
}
srate = (vob->mp3frequency != 0) ? vob->mp3frequency : vob->a_rate;
// need sox for speed changing?
if (speed > 0.0) {
/* check for sox */
if (tc_test_program("sox") != 0) return (TC_EXPORT_ERROR);
result = tc_snprintf(buf, PATH_MAX,
"sox %s -s -c %d -r %d -t raw - -r %d -t wav - speed %.10f | ",
vob->dm_bits == 16 ? "-w" : "-b",
vob->dm_chan,
vob->a_rate,
vob->a_rate,
speed);
if (result < 0)
return(TC_EXPORT_ERROR);
ptr = buf + strlen(buf);
}
result = tc_snprintf (ptr, PATH_MAX - strlen(buf),
"ffmpeg -y -f s%d%s -ac %d -ar %d -i - -ab %dk -ar %d -f mp2 %s%s",
vob->dm_bits,
((vob->dm_bits > 8) ? "le" : ""),
vob->dm_chan,
vob->a_rate,
vob->mp3bitrate,
srate,
out_fname,
vob->verbose > 1 ? "" : " >/dev/null 2>&1");
if (result < 0)
return(TC_EXPORT_ERROR);
if (verbose > 0)
tc_log_info (MOD_NAME, "%s", buf);
if ((pFile = popen (buf, "w")) == NULL)
return(TC_EXPORT_ERROR);
return(0);
}
if (param->flag == TC_VIDEO)
return(0);
// invalid flag
return(TC_EXPORT_ERROR);
}
/* ------------------------------------------------------------
*
* init codec
*
* ------------------------------------------------------------*/
MOD_init
{
if(param->flag == TC_AUDIO)
{
if (vob->ex_a_string) {
optstr_get(vob->ex_a_string, "speed", "%lf", &speed);
}
return(0);
}
if (param->flag == TC_VIDEO)
return(0);
// invalid flag
return(TC_EXPORT_ERROR);
}
/* ------------------------------------------------------------
*
* encode and export
*
* ------------------------------------------------------------*/
MOD_encode
{
if(param->flag == TC_AUDIO)
{
if (p_write (param->buffer, param->size) != param->size)
{
tc_log_perror(MOD_NAME, "write audio frame");
return(TC_EXPORT_ERROR);
}
return (0);
}
if (param->flag == TC_VIDEO)
return(0);
// invalid flag
return(TC_EXPORT_ERROR);
}
/* ------------------------------------------------------------
*
* stop codec
*
* ------------------------------------------------------------*/
MOD_stop
{
if (param->flag == TC_VIDEO)
return (0);
if (param->flag == TC_AUDIO)
return (0);
return(TC_EXPORT_ERROR);
}
/* ------------------------------------------------------------
*
* close codec
*
* ------------------------------------------------------------*/
MOD_close
{
if (param->flag == TC_VIDEO)
return (0);
if (param->flag == TC_AUDIO)
{
if (pFile)
pclose (pFile);
pFile = NULL;
return(0);
}
return (TC_EXPORT_ERROR);
}
/* vim: sw=4
*/