Autres/audacity
1
0
Fork 0
mirror of https://github.com/cookiengineer/audacity synced 2025-10-31 22:23:54 +01:00
Code Issues Releases Wiki Activity
Files
b3539ed2b84e2c678f9e645c55150d6fee0c2ea8
audacity/lib-src/twolame/libtwolame/twolame.c
Paul Licameli 548f221890 lib-src/twolame/libtwolame: eliminate warnings... 
... cast enum to int before testing for negative value which is not in the
enumeration but signifies "undefined"
2018-11-15 11:23:18 -05:00

935 lines
31 KiB
C
Raw Blame History

/*
* TwoLAME: an optimized MPEG Audio Layer Two encoder
*
* Copyright (C) 2001-2004 Michael Cheng
* Copyright (C) 2004-2006 The TwoLAME Project
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id$
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <limits.h>
#include "twolame.h"
#include "common.h"
#include "bitbuffer.h"
#include "mem.h"
#include "crc.h"
#include "dab.h"
#include "psycho_n1.h"
#include "psycho_0.h"
#include "psycho_1.h"
#include "psycho_2.h"
#include "psycho_3.h"
#include "psycho_4.h"
#include "availbits.h"
#include "subband.h"
#include "encode.h"
#include "energy.h"
#include "util.h"
#include "bitbuffer_inline.h"
/*
twolame_init
Create a set of encoding options and return a pointer to this structure
Returns NULL if unsuccessful (can't allocate memory)
Otherwise returns pointer to memory block
*/
twolame_options *twolame_init(void)
{
twolame_options *newoptions = NULL;
newoptions = (twolame_options *) TWOLAME_MALLOC(sizeof(twolame_options));
if (newoptions == NULL) {
return NULL;
}
newoptions->version = -1;
newoptions->num_channels_in = 0;
newoptions->num_channels_out = 0;
newoptions->samplerate_in = 0;
newoptions->samplerate_out = 0;
newoptions->mode = TWOLAME_AUTO_MODE; // Choose a proper mode later
newoptions->psymodel = 3;
newoptions->bitrate = -1; // Default bitrate is set in init_params
newoptions->vbr = FALSE;
newoptions->vbrlevel = 5.0;
newoptions->athlevel = 0.0;
newoptions->quickmode = FALSE;
newoptions->quickcount = 10;
newoptions->emphasis = TWOLAME_EMPHASIS_N;
newoptions->private_bit = 0;
newoptions->copyright = FALSE;
newoptions->original = TRUE;
newoptions->error_protection = FALSE;
newoptions->padding = TWOLAME_PAD_NO;
newoptions->do_dab = FALSE;
newoptions->dab_crc_len = 2;
newoptions->dab_xpad_len = 0;
newoptions->verbosity = 2;
newoptions->vbr_upper_index = 0;
newoptions->scale = 1.0; // scaling disabled
newoptions->scale_left = 1.0; // scaling disabled
newoptions->scale_right = 1.0; // scaling disabled
newoptions->do_energy_levels = FALSE;
newoptions->num_ancillary_bits = -1;
newoptions->vbr_frame_count = 0; // only used for debugging
newoptions->tablenum = 0;
newoptions->twolame_init = 0;
newoptions->subband = NULL;
newoptions->j_sample = NULL;
newoptions->sb_sample = NULL;
newoptions->psycount = 0;
newoptions->p0mem = NULL;
newoptions->p1mem = NULL;
newoptions->p2mem = NULL;
newoptions->p3mem = NULL;
newoptions->p4mem = NULL;
memset(newoptions->vbrstats, 0, sizeof(newoptions->vbrstats));
return (newoptions);
}
// Returns 0 if successful
// Returns -1 if unsuccessful
static int init_header_info(twolame_options * glopts)
{
frame_header *header = &glopts->header;
/* use the options to create header info structure */
header->lay = 2;
header->error_protection = glopts->error_protection;
header->version = glopts->version;
// Convert the sampling frequency to the required index
header->samplerate_idx = twolame_get_samplerate_index(glopts->samplerate_out);
if (header->samplerate_idx < 0) {
fprintf(stderr, "Not a valid samplerate: %i\n", glopts->samplerate_out);
return -1;
}
// Convert the bitrate to the an index
header->bitrate_index = twolame_get_bitrate_index(glopts->bitrate, header->version);
if (header->bitrate_index < 0) {
fprintf(stderr, "Not a valid bitrate (%i) for MPEG version '%s'\n", glopts->bitrate,
twolame_mpeg_version_name(glopts->version));
return -1;
}
// Convert the max VBR bitrate to the an index
glopts->vbr_upper_index = twolame_get_bitrate_index(glopts->vbr_max_bitrate, header->version);
if (glopts->vbr_upper_index < 0) {
fprintf(stderr, "Not a valid max VBR bitrate for this version: %i\n",
glopts->vbr_max_bitrate);
return -1;
}
// Copy accross the other settings
header->padding = glopts->padding;
header->private_bit = glopts->private_bit;
header->mode = glopts->mode;
header->mode_ext = 0;
header->copyright = glopts->copyright;
header->original = glopts->original;
header->emphasis = glopts->emphasis;
return 0;
}
/**
* This function should actually *check* the parameters to see if they
* make sense.
*/
int twolame_init_params(twolame_options * glopts)
{
if (glopts->twolame_init) {
fprintf(stderr, "Already called twolame_init_params() once.\n");
return 1;
}
// Check the number of channels
if (glopts->num_channels_in != 1 && glopts->num_channels_in != 2) {
fprintf(stderr,
"twolame_init_params(): must specify number of input channels using twolame_set_num_channels().\n");
return -1;
}
// If not output samplerate has been set, then set it to the input sample rate
if (glopts->samplerate_out < 1) {
glopts->samplerate_out = glopts->samplerate_in;
}
// If the MPEG version has not been set, then choose automatically
if ((int)glopts->version == -1) {
// Get the MPEG version for the chosen samplerate
glopts->version = twolame_get_version_for_samplerate(glopts->samplerate_out);
if ((int)glopts->version < 0) {
fprintf(stderr, "twolame_init_params(): invalid samplerate: %i\n",
glopts->samplerate_out);
return -1;
} else if (glopts->verbosity >= 3) {
fprintf(stderr, "Chosen version '%s' for samplerate of %d Hz.\n",
twolame_mpeg_version_name(glopts->version), glopts->samplerate_out);
}
}
// Choose mode (if none chosen)
if (glopts->mode == TWOLAME_AUTO_MODE) {
if (glopts->num_channels_in == 2)
glopts->mode = TWOLAME_STEREO;
else
glopts->mode = TWOLAME_MONO;
if (glopts->verbosity >= 3) {
fprintf(stderr, "Chosen mode to be '%s' because of %d input channels.\n",
twolame_get_mode_name(glopts), glopts->num_channels_in);
}
}
// Choose the bitrate (if none chosen)
if (glopts->bitrate <= 0) {
if (glopts->mode == TWOLAME_MONO) {
switch (glopts->samplerate_out) {
case 48000:
glopts->bitrate = 96;
break; // (LAME=64)
case 44100:
glopts->bitrate = 96;
break; // (LAME=64)
case 32000:
glopts->bitrate = 80;
break; // (LAME=48)
case 24000:
glopts->bitrate = 48;
break; // (LAME=32)
case 22050:
glopts->bitrate = 48;
break; // (LAME=32)
case 16000:
glopts->bitrate = 32;
break; // (LAME=24)
}
} else {
switch (glopts->samplerate_out) {
case 48000:
glopts->bitrate = 192;
break; // (LAME=128)
case 44100:
glopts->bitrate = 192;
break; // (LAME=128)
case 32000:
glopts->bitrate = 160;
break; // (LAME=96)
case 24000:
glopts->bitrate = 96;
break; // (LAME=64)
case 22050:
glopts->bitrate = 96;
break; // (LAME=64)
case 16000:
glopts->bitrate = 64;
break; // (LAME=48)
}
}
if (glopts->verbosity >= 3) {
fprintf(stderr, "Chosen bitrate of %dkbps for samplerate of %d Hz.\n",
glopts->bitrate, glopts->samplerate_out);
}
}
/* Can't do DAB and energylevel extensions at the same time Because both of them think they're
the only ones inserting information into the ancillary section of the frame */
if (glopts->do_dab && glopts->do_energy_levels) {
fprintf(stderr, "Error: Can't do DAB and Energy Levels at the same time\n");
return -1;
}
/* Set the number of ancillary bits automatically, if none set */
if (glopts->num_ancillary_bits < 0) {
if (glopts->do_energy_levels) {
glopts->num_ancillary_bits = get_required_energy_bits(glopts);
} else {
glopts->num_ancillary_bits = 0;
}
}
/* Check that if we're doing energy levels, that there's enough space to put the information */
if (glopts->do_energy_levels) {
int required = get_required_energy_bits(glopts);
if (glopts->num_ancillary_bits < required) {
fprintf(stderr, "Warning: Too few ancillary bits to store energy levels: %i<%i\n",
glopts->num_ancillary_bits, required);
return -1;
}
}
/*
* MFC Feb 2003: in VBR mode, joint
* stereo doesn't make any sense at
* the moment, as there are no noisy
* subbands according to
* bits_for_nonoise in vbr mode
*/
if (glopts->vbr && glopts->mode == TWOLAME_JOINT_STEREO) {
fprintf(stderr, "Warning: Can't do Joint Stereo with VBR, switching to normal stereo.\n");
// force stereo mode
twolame_set_mode(glopts, TWOLAME_STEREO);
}
/* Can't do padding and VBR at same time */
if (glopts->vbr && glopts->padding == TRUE) {
fprintf(stderr, "Error: Can't do padding and VBR at same time\n");
return -1;
}
// Set the Number of output channels
glopts->num_channels_out = (glopts->mode == TWOLAME_MONO) ? 1 : 2;
// build mpeg header from parameters
if (init_header_info(glopts) < 0) {
return -1;
}
// Select table number and sblimit
if (encode_init(glopts) < 0) {
return -1;
}
// initialise bitrate allocation
if (init_bit_allocation(glopts) < 0) {
return -1;
}
// Check input samplerate is same as output samplerate
if (glopts->samplerate_out != glopts->samplerate_in) {
fprintf(stderr,
"twolame_init_params(): sorry, twolame doesn't support resampling (yet).\n");
return -1;
}
// Initialise interal variables
glopts->samples_in_buffer = 0;
glopts->psycount = 0;
// Allocate memory to larger buffers
glopts->subband = (subband_t *) TWOLAME_MALLOC(sizeof(subband_t));
glopts->j_sample = (jsb_sample_t *) TWOLAME_MALLOC(sizeof(jsb_sample_t));
glopts->sb_sample = (sb_sample_t *) TWOLAME_MALLOC(sizeof(sb_sample_t));
// clear buffers
memset((char *) glopts->buffer, 0, sizeof(glopts->buffer));
memset((char *) glopts->bit_alloc, 0, sizeof(glopts->bit_alloc));
memset((char *) glopts->scfsi, 0, sizeof(glopts->scfsi));
memset((char *) glopts->scalar, 0, sizeof(glopts->scalar));
memset((char *) glopts->j_scale, 0, sizeof(glopts->j_scale));
memset((char *) glopts->smrdef, 0, sizeof(glopts->smrdef));
memset((char *) glopts->smr, 0, sizeof(glopts->smr));
memset((char *) glopts->max_sc, 0, sizeof(glopts->max_sc));
// Initialise subband windowfilter
if (init_subband(&glopts->smem) < 0) {
return -1;
}
// All initalised now :)
glopts->twolame_init++;
return (0);
}
/* Scale the samples in the frame sample buffer
using the user specified values
and downmix/upmix according to the number of input/output channels
*/
static void scale_and_mix_samples(twolame_options * glopts)
{
int num_samples = glopts->samples_in_buffer;
int i;
// apply scaling to both channels
if (glopts->scale != 0 && glopts->scale != 1.0) {
for (i = 0; i < num_samples; ++i) {
glopts->buffer[0][i] *= glopts->scale;
if (glopts->num_channels_in == 2)
glopts->buffer[1][i] *= glopts->scale;
}
}
// apply scaling to channel 0 (left)
if (glopts->scale_left != 0 && glopts->scale_left != 1.0) {
for (i = 0; i < num_samples; ++i) {
glopts->buffer[0][i] *= glopts->scale_left;
}
}
// apply scaling to channel 1 (right)
if (glopts->scale_right != 0 && glopts->scale_right != 1.0) {
for (i = 0; i < num_samples; ++i) {
glopts->buffer[1][i] *= glopts->scale_right;
}
}
// Downmix to Mono if 2 channels in and 1 channel out
if (glopts->num_channels_in == 2 && glopts->num_channels_out == 1) {
for (i = 0; i < num_samples; ++i) {
glopts->buffer[0][i] = ((long) glopts->buffer[0][i] + glopts->buffer[1][i]) / 2;
glopts->buffer[1][i] = 0;
}
}
// Upmix to Stereo if 2 channels out and 1 channel in
if (glopts->num_channels_in == 1 && glopts->num_channels_out == 2) {
for (i = 0; i < num_samples; ++i) {
glopts->buffer[1][i] = glopts->buffer[0][i];
}
}
}
/*
Encode a single frame of audio from 1152 samples
Audio samples are taken from glopts->buffer
Encoded bit stream is placed in to parameter bs
(not intended for use outside the library)
Returns the size of the frame
or -1 if there is an error
*/
static int encode_frame(twolame_options * glopts, bit_stream * bs)
{
int nch = glopts->num_channels_out;
int sb, ch, adb, i;
unsigned long frameBits, initial_bits;
short sam[2][1056];
if (!glopts->twolame_init) {
fprintf(stderr, "Please call twolame_init_params() before starting encoding.\n");
return -1;
}
// Scale and mix the input buffer
scale_and_mix_samples(glopts);
// Clear the saved audio buffer
memset((char *) sam, 0, sizeof(sam));
// Number of bits to calculate CRC on
glopts->num_crc_bits = 0;
// Store the number of bits initially in the bit buffer
initial_bits = buffer_sstell(bs);
adb = available_bits(glopts);
/* allow the user to reserve some space at the end of the frame This will however leave fewer
bits for the audio. Need to do a sanity check here to see that there are *some* bits left. */
if (glopts->num_ancillary_bits > 0.6 * adb) {
/* Trying to reserve more than 60% of the frame. 0.6 is arbitrary. but since most
applications probably only want to reserve a few bytes, this seems fine. Typical frame
size is about 800bytes */
fprintf(stderr,
"You're trying to reserve more than 60%% of the mpeg frame for ancillary data\n");
fprintf(stderr, "This is probably an error. But I'll keep going anyway...\n");
}
adb -= glopts->num_ancillary_bits;
/* MFC 26 July 2003 Doing DAB became a bit harder in the reorganisation of the code. Now there
is no guarantee that there is more than one frame in the bitbuffer. But DAB requires that
the CRC for the *current* frame be written at the end of the *previous* frame. Workaround:
Users (Nicholas?) wanting to implement DAB will have to do some work in the frontend. First:
Reserve some bits for yourself (options->num_ancillary_bits) Second: Put the encoder into
"single frame mode" i.e. only read 1152 samples per channel.
(frontendoptions->singleFrameMode) Third: When you receive each mp2 frame back from the
library, you'll have to insert the options->dabCrc[i] values into the end of the frame
yourself. (DAB crc calc is done below) The frontend will have to keep the previous frame in
memory. As of 26July all that needs to be done is for the frontend to buffer one frame in
memory, such that the CRC for the next frame can be written in at the end of it. */
{
int gr, bl, ch;
/* New polyphase filter Combines windowing and filtering. Ricardo Feb'03 */
for (gr = 0; gr < 3; gr++)
for (bl = 0; bl < 12; bl++)
for (ch = 0; ch < nch; ch++)
window_filter_subband(&glopts->smem,
&glopts->buffer[ch][gr * 12 * 32 + 32 * bl], ch,
&(*glopts->sb_sample)[ch][gr][bl][0]);
}
scalefactor_calc(*glopts->sb_sample, glopts->scalar, nch, glopts->sblimit);
find_sf_max(glopts, glopts->scalar, glopts->max_sc);
if (glopts->mode == TWOLAME_JOINT_STEREO) {
// this way we calculate more mono than we need but it is cheap
combine_lr(*glopts->sb_sample, *glopts->j_sample, glopts->sblimit);
scalefactor_calc(glopts->j_sample, &glopts->j_scale, 1, glopts->sblimit);
}
if ((glopts->quickmode == TRUE) && (++glopts->psycount % glopts->quickcount != 0)) {
/* We're using quick mode, so we're only calculating the model every 'quickcount' frames.
Otherwise, just copy the old ones across */
for (ch = 0; ch < nch; ch++) {
for (sb = 0; sb < SBLIMIT; sb++) {
glopts->smr[ch][sb] = glopts->smrdef[ch][sb];
}
}
} else {
// calculate the psymodel
switch (glopts->psymodel) {
case -1:
psycho_n1(glopts, glopts->smr, nch);
break;
case 0: // Psy Model A
psycho_0(glopts, glopts->smr, glopts->scalar);
break;
case 1:
psycho_1(glopts, glopts->buffer, glopts->max_sc, glopts->smr);
break;
case 2:
psycho_2(glopts, glopts->buffer, sam, glopts->smr);
break;
case 3:
// Modified psy model 1
psycho_3(glopts, glopts->buffer, glopts->max_sc, glopts->smr);
break;
case 4:
// Modified psy model 2
psycho_4(glopts, glopts->buffer, sam, glopts->smr);
break;
default:
fprintf(stderr, "Invalid psy model specification: %i\n", glopts->psymodel);
return -1;
break;
}
if (glopts->quickmode == TRUE) {
// copy the smr values and reuse them later
for (ch = 0; ch < nch; ch++) {
for (sb = 0; sb < SBLIMIT; sb++)
glopts->smrdef[ch][sb] = glopts->smr[ch][sb];
}
}
}
sf_transmission_pattern(glopts, glopts->scalar, glopts->scfsi);
main_bit_allocation(glopts, glopts->smr, glopts->scfsi, glopts->bit_alloc, &adb);
write_header(glopts, bs);
// Leave space for 2 bytes of CRC to be filled in later
if (glopts->error_protection)
buffer_putbits(bs, 0, 16);
write_bit_alloc(glopts, glopts->bit_alloc, bs);
write_scalefactors(glopts, glopts->bit_alloc, glopts->scfsi, glopts->scalar, bs);
subband_quantization(glopts, glopts->scalar, *glopts->sb_sample, glopts->j_scale,
*glopts->j_sample, glopts->bit_alloc, *glopts->subband);
write_samples(glopts, *glopts->subband, glopts->bit_alloc, bs);
// If not all the bits were used, write out a stack of zeros
for (i = 0; i < adb; i++)
buffer_put1bit(bs, 0);
/* MFC July 03 FIXME Write an extra byte for 16/24/32/48 input when padding is on. Something
must be going astray with the frame size calcs. This fudge works fine for the moment */
if ((glopts->header.samplerate_idx != 0) && (glopts->padding)) // i.e. not a 44.1 or 22kHz
// input file
buffer_putbits(bs, 0, 8);
if (glopts->do_dab) {
// Do the CRC calc for DAB stuff if required.
// It will be up to the frontend to insert it into the end of the
// previous frame.
for (i = glopts->dab_crc_len - 1; i >= 0; i--) {
dab_crc_calc(glopts, glopts->bit_alloc, glopts->scfsi, glopts->scalar,
&glopts->dab_crc[i], i);
}
}
// Allocate space for the reserved ancillary bits
for (i = 0; i < glopts->num_ancillary_bits; i++)
buffer_put1bit(bs, 0);
// Calulate the number of bits in this frame
frameBits = buffer_sstell(bs) - initial_bits;
if (frameBits % 8) { /* a program failure */
fprintf(stderr, "Sent %ld bits = %ld slots plus %ld\n", frameBits, frameBits / 8,
frameBits % 8);
fprintf(stderr, "If you are reading this, the program is broken\n");
fprintf(stderr, "email %s with the command line arguments and other info\n",
PACKAGE_BUGREPORT);
return -1;
}
// Store the energy levels at the end of the frame
if (glopts->do_energy_levels)
do_energy_levels(glopts, bs);
// MEANX: Recompute checksum from bitstream
if (glopts->error_protection) {
unsigned char *frame_ptr = bs->buf + (initial_bits >> 3);
crc_writeheader(frame_ptr, glopts->num_crc_bits);
}
// fprintf(stderr,"Frame size: %li\n\n",frameBits/8);
return frameBits / 8;
}
/*
glopts
leftpcm - holds left channel (or mono channel)
rightpcm - d'uh
num_samples - the number of samples in each channel
mp2buffer - a pointer to the place where we want the mpeg data to be written
mp2buffer_size - how much space the user allocated for this buffer
mp2fill_size - how much mpeg data the library has put into the mp2buffer
*/
int twolame_encode_buffer(twolame_options * glopts,
const short int leftpcm[],
const short int rightpcm[],
int num_samples, unsigned char *mp2buffer, int mp2buffer_size)
{
int mp2_size = 0;
bit_stream *mybs;
int i;
if (num_samples == 0)
return 0;
// now would be a great time to validate the size of the buffer.
// samples/1152 * sizeof(frame) < mp2buffer_size
mybs = buffer_init(mp2buffer, mp2buffer_size);
// Use up all the samples in in_buffer
while (num_samples) {
// fill up glopts->buffer with as much as we can
int samples_to_copy = TWOLAME_SAMPLES_PER_FRAME - glopts->samples_in_buffer;
if (num_samples < samples_to_copy)
samples_to_copy = num_samples;
/* Copy across samples */
for (i = 0; i < samples_to_copy; i++) {
glopts->buffer[0][glopts->samples_in_buffer + i] = *leftpcm++;
if (glopts->num_channels_in == 2)
glopts->buffer[1][glopts->samples_in_buffer + i] = *rightpcm++;
}
/* Update sample counts */
glopts->samples_in_buffer += samples_to_copy;
num_samples -= samples_to_copy;
// is there enough to encode a whole frame ?
if (glopts->samples_in_buffer >= TWOLAME_SAMPLES_PER_FRAME) {
int bytes = encode_frame(glopts, mybs);
if (bytes <= 0) {
buffer_deinit(&mybs);
return bytes;
}
mp2_size += bytes;
glopts->samples_in_buffer -= TWOLAME_SAMPLES_PER_FRAME;
}
}
// free up the bit stream buffer structure
buffer_deinit(&mybs);
return (mp2_size);
}
int twolame_encode_buffer_interleaved(twolame_options * glopts,
const short int pcm[],
int num_samples, unsigned char *mp2buffer, int mp2buffer_size)
{
int mp2_size = 0;
bit_stream *mybs;
int i;
if (num_samples == 0)
return 0;
// now would be a great time to validate the size of the buffer.
// samples/1152 * sizeof(frame) < mp2buffer_size
mybs = buffer_init(mp2buffer, mp2buffer_size);
// Use up all the samples in in_buffer
while (num_samples) {
// fill up glopts->buffer with as much as we can
int samples_to_copy = TWOLAME_SAMPLES_PER_FRAME - glopts->samples_in_buffer;
if (num_samples < samples_to_copy)
samples_to_copy = num_samples;
/* Copy across samples */
for (i = 0; i < samples_to_copy; i++) {
glopts->buffer[0][glopts->samples_in_buffer + i] = *pcm++;
if (glopts->num_channels_in == 2)
glopts->buffer[1][glopts->samples_in_buffer + i] = *pcm++;
}
/* Update sample counts */
glopts->samples_in_buffer += samples_to_copy;
num_samples -= samples_to_copy;
// is there enough to encode a whole frame ?
if (glopts->samples_in_buffer >= TWOLAME_SAMPLES_PER_FRAME) {
int bytes = encode_frame(glopts, mybs);
if (bytes <= 0) {
buffer_deinit(&mybs);
return bytes;
}
mp2_size += bytes;
glopts->samples_in_buffer -= TWOLAME_SAMPLES_PER_FRAME;
}
}
// free up the bit stream buffer structure
buffer_deinit(&mybs);
return (mp2_size);
}
static void float32_to_short(const float in[], short out[], int num_samples, int stride)
{
int n;
for (n = 0; n < num_samples; n++) {
int tmp = lrintf(in[n * stride] * 32768.0f);
if (tmp > SHRT_MAX) {
out[n] = SHRT_MAX;
} else if (tmp < SHRT_MIN) {
out[n] = SHRT_MIN;
} else {
out[n] = (short) tmp;
}
}
}
/*
glopts
leftpcm - holds left channel (or mono channel)
rightpcm - d'uh
num_samples - the number of samples in each channel
mp2buffer - a pointer to the place where we want the mpeg data to be written
mp2buffer_size - how much space the user allocated for this buffer
mp2fill_size - how much mpeg data the library has put into the mp2buffer
*/
int twolame_encode_buffer_float32(twolame_options * glopts,
const float leftpcm[],
const float rightpcm[],
int num_samples, unsigned char *mp2buffer, int mp2buffer_size)
{
int mp2_size = 0;
bit_stream *mybs;
if (num_samples == 0)
return 0;
// now would be a great time to validate the size of the buffer.
// samples/1152 * sizeof(frame) < mp2buffer_size
mybs = buffer_init(mp2buffer, mp2buffer_size);
// Use up all the samples in in_buffer
while (num_samples) {
// fill up glopts->buffer with as much as we can
int samples_to_copy = TWOLAME_SAMPLES_PER_FRAME - glopts->samples_in_buffer;
if (num_samples < samples_to_copy)
samples_to_copy = num_samples;
/* Copy across samples */
float32_to_short(leftpcm, &glopts->buffer[0][glopts->samples_in_buffer], samples_to_copy,
1);
if (glopts->num_channels_in == 2)
float32_to_short(rightpcm, &glopts->buffer[1][glopts->samples_in_buffer],
samples_to_copy, 1);
leftpcm += samples_to_copy;
rightpcm += samples_to_copy;
/* Update sample counts */
glopts->samples_in_buffer += samples_to_copy;
num_samples -= samples_to_copy;
// is there enough to encode a whole frame ?
if (glopts->samples_in_buffer >= TWOLAME_SAMPLES_PER_FRAME) {
int bytes = encode_frame(glopts, mybs);
if (bytes <= 0) {
buffer_deinit(&mybs);
return bytes;
}
mp2_size += bytes;
glopts->samples_in_buffer -= TWOLAME_SAMPLES_PER_FRAME;
}
}
// free up the bit stream buffer structure
buffer_deinit(&mybs);
return (mp2_size);
}
int twolame_encode_buffer_float32_interleaved(twolame_options * glopts,
const float pcm[],
int num_samples,
unsigned char *mp2buffer, int mp2buffer_size)
{
int mp2_size = 0;
bit_stream *mybs;
if (num_samples == 0)
return 0;
// now would be a great time to validate the size of the buffer.
// samples/1152 * sizeof(frame) < mp2buffer_size
mybs = buffer_init(mp2buffer, mp2buffer_size);
// Use up all the samples in in_buffer
while (num_samples) {
// fill up glopts->buffer with as much as we can
int samples_to_copy = TWOLAME_SAMPLES_PER_FRAME - glopts->samples_in_buffer;
if (num_samples < samples_to_copy)
samples_to_copy = num_samples;
/* Copy across samples */
float32_to_short(pcm, &glopts->buffer[0][glopts->samples_in_buffer], samples_to_copy,
glopts->num_channels_in);
if (glopts->num_channels_in == 2)
float32_to_short(pcm + 1, &glopts->buffer[1][glopts->samples_in_buffer],
samples_to_copy, glopts->num_channels_in);
pcm += (samples_to_copy * glopts->num_channels_in);
/* Update sample counts */
glopts->samples_in_buffer += samples_to_copy;
num_samples -= samples_to_copy;
// is there enough to encode a whole frame ?
if (glopts->samples_in_buffer >= TWOLAME_SAMPLES_PER_FRAME) {
int bytes = encode_frame(glopts, mybs);
if (bytes <= 0) {
buffer_deinit(&mybs);
return bytes;
}
mp2_size += bytes;
glopts->samples_in_buffer -= TWOLAME_SAMPLES_PER_FRAME;
}
}
// free up the bit stream buffer structure
buffer_deinit(&mybs);
return (mp2_size);
}
int twolame_encode_flush(twolame_options * glopts, unsigned char *mp2buffer, int mp2buffer_size)
{
bit_stream *mybs = NULL;
int mp2_size = 0;
int i;
if (glopts->samples_in_buffer == 0) {
// No samples left over
return 0;
}
// Create bit stream structure
mybs = buffer_init(mp2buffer, mp2buffer_size);
// Pad out the PCM buffers with 0 and encode the frame
for (i = glopts->samples_in_buffer; i < TWOLAME_SAMPLES_PER_FRAME; i++) {
glopts->buffer[0][i] = glopts->buffer[1][i] = 0;
}
// Encode the frame
mp2_size = encode_frame(glopts, mybs);
glopts->samples_in_buffer = 0;
// free up the bit stream buffer structure
buffer_deinit(&mybs);
return mp2_size;
}
void twolame_close(twolame_options ** glopts)
{
twolame_options *opts = NULL;
// Check input pointers aren't NULL
if (glopts == NULL)
return;
opts = *glopts;
if (opts == NULL)
return;
// free mem
psycho_4_deinit(&opts->p4mem);
psycho_3_deinit(&opts->p3mem);
psycho_2_deinit(&opts->p2mem);
psycho_1_deinit(&opts->p1mem);
psycho_0_deinit(&opts->p0mem);
TWOLAME_FREE(opts->subband);
TWOLAME_FREE(opts->j_sample);
TWOLAME_FREE(opts->sb_sample);
// Free the memory and zero the pointer
TWOLAME_FREE(opts);
}
// vim:ts=4:sw=4:nowrap:
Reference in New Issue View Git Blame Copy Permalink