mirror of
https://github.com/cookiengineer/audacity
synced 2025-11-04 08:04:06 +01:00
259 lines
7.7 KiB
C
259 lines
7.7 KiB
C
/*
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* TwoLAME: an optimized MPEG Audio Layer Two encoder
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*
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* Copyright (C) 2001-2004 Michael Cheng
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* Copyright (C) 2004-2006 The TwoLAME Project
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* $Id$
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <math.h>
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#include <assert.h>
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#include "twolame.h"
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#include "common.h"
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#include "util.h"
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// Return string containg version number
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// of this library
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const char *get_twolame_version(void)
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{
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const char *str = PACKAGE_VERSION;
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return str;
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}
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// Return string containg version number
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// of this library
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const char *get_twolame_url(void)
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{
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const char *str = "http://www.twolame.org";
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return str;
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}
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/* 1: MPEG-1, 0: MPEG-2 LSF, 1995-07-11 shn */
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static const int bitrate_table[2][15] = {
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{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160},
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{0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384}
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};
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//
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// Returns a name string for MPEG version enumeration
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//
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const char *twolame_mpeg_version_name(int version)
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{
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static const char *version_name[3] = { "MPEG-2 LSF", "MPEG-1", "Illegal Version" };
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if (version == 0)
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return (version_name[0]);
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if (version == 1)
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return (version_name[1]);
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return (version_name[2]);
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}
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// Returns the index associated with a bitrate for
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// the specified version of MPEG.
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//
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// Returns -1 for invalid bitrates
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//
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int twolame_get_bitrate_index(int bitrate, TWOLAME_MPEG_version version)
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{
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int index = 0;
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int found = 0;
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// MFC sanity check.
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if (version != 0 && version != 1) {
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fprintf(stderr, "twolame_get_bitrate_index: invalid version index %i\n", version);
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return -1;
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}
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while (!found && index < 15) {
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if (bitrate_table[version][index] == bitrate)
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found = 1;
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else
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++index;
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}
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if (found)
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return (index);
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else {
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fprintf(stderr,
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"twolame_get_bitrate_index: %d is not a legal bitrate for version '%s'\n",
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bitrate, twolame_mpeg_version_name(version));
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return -1;
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}
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}
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// convert samp frq in Hz to index
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// legal rates 16000, 22050, 24000, 32000, 44100, 48000
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// -1 is returned for invalid samplerates
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int twolame_get_samplerate_index(long sample_rate)
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{
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switch (sample_rate) {
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case 44100L:
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return 0;
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case 48000L:
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return 1;
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case 32000L:
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return 2;
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case 22050L:
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return 0;
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case 24000L:
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return 1;
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case 16000L:
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return 2;
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}
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// Invalid choice of samplerate
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fprintf(stderr, "twolame_get_samplerate_index: %ld is not a legal sample rate\n", sample_rate);
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return -1;
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}
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// Return the MPEG Version to use for the specified samplerate
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// -1 is returned for invalid samplerates
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int twolame_get_version_for_samplerate(long sample_rate)
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{
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switch (sample_rate) {
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case 48000L:
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return TWOLAME_MPEG1;
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case 44100L:
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return TWOLAME_MPEG1;
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case 32000L:
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return TWOLAME_MPEG1;
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case 24000L:
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return TWOLAME_MPEG2;
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case 22050L:
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return TWOLAME_MPEG2;
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case 16000L:
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return TWOLAME_MPEG2;
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}
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// Invalid choice of samplerate
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fprintf(stderr, "twolame_get_version_for_samplerate: %ld is not a legal sample rate\n",
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sample_rate);
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return -1;
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}
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// Get the number of bytes per frame, for current settings
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int twolame_get_framelength(twolame_options * glopts)
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{
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int bytes = 144 * (glopts->bitrate * 1000) / glopts->samplerate_out;
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if (glopts->padding)
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bytes++;
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return bytes;
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}
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// Print the library version and
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// encoder parameter settings to STDERR
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void twolame_print_config(twolame_options * glopts)
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{
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FILE *fd = stderr;
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// Are we being silent ?
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if (glopts->verbosity <= 0)
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return;
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// Are we being brief ?
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if (glopts->verbosity == 1) {
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fprintf(fd, "LibTwoLame version %s (%s)\n", get_twolame_version(), get_twolame_url());
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fprintf(fd, "Encoding as %dHz, ", twolame_get_out_samplerate(glopts));
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fprintf(fd, "%d kbps, ", twolame_get_bitrate(glopts));
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if (twolame_get_VBR(glopts))
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fprintf(fd, "VBR, ");
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else
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fprintf(fd, "CBR, ");
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fprintf(fd, "%s Layer II\n", twolame_get_version_name(glopts));
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} else {
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fprintf(fd, "---------------------------------------------------------\n");
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fprintf(fd, "LibTwoLame %s (%s)\n", get_twolame_version(), get_twolame_url());
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fprintf(fd, "Input : %d Hz, %d channels\n",
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twolame_get_in_samplerate(glopts), twolame_get_num_channels(glopts));
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fprintf(fd, "Output: %d Hz, %s\n",
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twolame_get_out_samplerate(glopts), twolame_get_mode_name(glopts));
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fprintf(fd, "%d kbps ", twolame_get_bitrate(glopts));
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if (twolame_get_VBR(glopts))
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fprintf(fd, "VBR ");
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else
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fprintf(fd, "CBR ");
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fprintf(fd, "%s Layer II ", twolame_get_version_name(glopts));
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fprintf(fd, "psycho model=%d \n", twolame_get_psymodel(glopts));
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fprintf(fd, "[De-emph:%s Copyright:%s Original:%s]\n",
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((twolame_get_emphasis(glopts)) ? "On " : "Off"),
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((twolame_get_copyright(glopts)) ? "Yes" : "No "),
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((twolame_get_original(glopts)) ? "Yes" : "No "));
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fprintf(fd, "[Padding:%s CRC:%s Energy:%s ]\n",
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((twolame_get_padding(glopts)) ? "Normal" : "Off "),
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((twolame_get_error_protection(glopts)) ? "On " : "Off"),
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((twolame_get_energy_levels(glopts)) ? "On " : "Off"));
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if (glopts->verbosity >= 3) {
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if (twolame_get_VBR(glopts)) {
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fprintf(fd, " - VBR Enabled. Using MNR boost of %f\n",
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twolame_get_VBR_level(glopts));
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fprintf(fd, " - VBR bitrate index limits [%i -> %i]\n", glopts->lower_index,
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glopts->upper_index);
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}
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fprintf(fd, " - ATH adjustment %f\n", twolame_get_ATH_level(glopts));
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if (twolame_get_num_ancillary_bits(glopts))
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fprintf(fd, " - Reserving %i ancillary bits\n",
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twolame_get_num_ancillary_bits(glopts));
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if (twolame_get_scale(glopts) != 1.0f)
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fprintf(fd, " - Scaling audio by %f\n", twolame_get_scale(glopts));
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if (twolame_get_scale_left(glopts) != 1.0f)
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fprintf(fd, " - Scaling left channel by %f\n", twolame_get_scale_left(glopts));
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if (twolame_get_scale_right(glopts) != 1.0f)
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fprintf(fd, " - Scaling right channel by %f\n", twolame_get_scale_right(glopts));
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// if (glopts->num_channels_in == 2 && glopts->num_channels_out == 1 ) {
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// fprintf(fd, " - Downmixing from stereo to mono.\n");
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// } else if (glopts->num_channels_in == 1 && glopts->num_channels_out == 2 ) {
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// fprintf(fd, " - Upmixing from mono to stereo.\n");
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// }
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}
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fprintf(fd, "---------------------------------------------------------\n");
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}
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}
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// vim:ts=4:sw=4:nowrap:
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