// Returns the index associated with a bitrate for
// the specified version of MPEG.
//
// Returns -1 for invalid bitrates
//
int twolame_get_bitrate_index(int bitrate, TWOLAME_MPEG_version version)
{
int index = 0;
int found = 0;
// MFC sanity check.
if (version!=0 && version!=1) {
fprintf(stderr,"twolame_get_bitrate_index: invalid version index %i\n",version);
return -1;
}
while (!found && index < 15) {
if (bitrate_table[version][index] == bitrate)
found = 1;
else
++index;
}
if (found) return (index);
else {
fprintf (stderr,
"twolame_get_bitrate_index: %d is not a legal bitrate for version '%s'\n",
bitrate, twolame_mpeg_version_name(version));
return -1;
}
}
// 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
if (glopts->freeformat)
header->bitrate_index = 0;
else
{
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;
}
}
if (glopts->vbr && glopts->vbr_max_bitrate > 0)
{
/* user required vbr and a specified max bitrate */
/* convert max VBR bitrate to 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 = 0; /* when requested, padding will be evaluated later for this frame */
header->private_extension = glopts->private_extension;
header->mode = glopts->mode;
header->mode_ext = 0;
header->copyright = glopts->copyright;
header->original = glopts->original;
header->emphasis = glopts->emphasis;
return 0;
}
// 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(stdout,"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(stdout,"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(stdout,"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;
}
// Returns the index associated with a bitrate for
// the specified version of MPEG.
//
// Returns -1 for invalid bitrates
//
int twolame_get_bitrate_index(int bitrate, TWOLAME_MPEG_version version)
{
int index = 0;
// MFC sanity check.
if (version != 0 && version != 1) {
fprintf(stderr, "twolame_get_bitrate_index: invalid version index %i\n", version);
return -1;
}
while (++index < 15)
if (bitrate_table[version][index] == bitrate)
break;
if (index == 15) {
fprintf(stderr,
"twolame_get_bitrate_index: %d is not a legal bitrate for version '%s'\n",
bitrate, twolame_mpeg_version_name(version));
return -1;
}
return (index);
}
const char *twolame_get_version_name(twolame_options * glopts)
{
return twolame_mpeg_version_name(glopts->version);
}
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) {
if (glopts->num_channels_in == 0) {
/* this error is due to the caller frontend */
fprintf(stderr,
"twolame_init_params(): must specify number of input channels using twolame_set_num_channels().\n");
}
else {
/* this error is due to the user feeding a wrong file */
fprintf(stderr,
"Error: twolame cannot encode files with more than 2 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 (glopts->version == -1) {
// Get the MPEG version for the chosen samplerate
glopts->version = twolame_get_version_for_samplerate(glopts->samplerate_out);
if (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 && !glopts->vbr) {
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);
}
glopts->freeformat = FALSE; // no sense in requiring freeformat encoding without setting a bitrate
}
if (glopts->bitrate < 0 && glopts->vbr) {
/* set the minimum bitrate - 'init_bit_allocation' will fix it if needed */
glopts->bitrate = twolame_index_bitrate((int)glopts->version, 1);
}
/* Check for bitrate validity */
if (glopts->version == TWOLAME_MPEG1
&&
!glopts->freeformat
&&
!glopts->vbr) {
/* some limitation apply for MPEG1 when CBR and freeformat is not selected */
if (glopts->mode == TWOLAME_MONO) {
if (glopts->bitrate > 192) {
fprintf(stderr, "twolame_init_params(): %dkbps is an invalid bitrate for mono encoding.\n",
glopts->bitrate);
return -1;
}
}
else {
if (glopts->bitrate < 64 || glopts->bitrate == 80) {
fprintf(stderr, "twolame_init_params(): %dkbps is an invalid bitrate for 2ch encoding.\n",
glopts->bitrate);
return -1;
}
}
}
/* 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 = twolame_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 = twolame_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;
}
/* Simple patch for the `bit_stream buffer needs to be bigger' warning */
/* Fix FREEFORMAT_MAX_BITRATE definition when github issue #51 will be closed */
if (glopts->freeformat && glopts->bitrate > FREEFORMAT_MAX_BITRATE) {
fprintf(stderr, "twolame_init_params(): cannot encode freeformat stream at %d kbps\n", glopts->bitrate);
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;
}
// initialise bitrate allocation
if (twolame_init_bit_allocation(glopts) < 0) {
return -1;
}
// Select table number and sblimit
if (twolame_encode_init(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));
if (glopts->subband == NULL
||
glopts->j_sample == NULL
||
glopts->sb_sample == NULL)
{
TWOLAME_FREE(glopts->subband);
TWOLAME_FREE(glopts->j_sample);
TWOLAME_FREE(glopts->sb_sample);
return -1;
}
// 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 (twolame_init_subband(&glopts->smem) < 0) {
return -1;
}
// All initalised now :)
glopts->twolame_init++;
return (0);
}
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 != 1 && glopts->num_channels != 2) {
fprintf(stderr,"twolame_init_params(): must specify number of channels in input samples 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 (glopts->version == -1) {
// Get the MPEG version for the chosen samplerate
glopts->version = twolame_get_version_for_samplerate( glopts->samplerate_out );
if (glopts->version < 0) {
fprintf(stdout,"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 == 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);
}
}
// 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,"Can't do DAB and Energy Levels at the same time\n");
return -1;
}
/* Check that if we're doing energy levels, that there's enough space
to put the information */
if (glopts->do_energy_levels) {
if ((glopts->mode==TWOLAME_MONO)&&(glopts->num_ancillary_bits<16)) {
fprintf(stderr,"Too few ancillary bits: %i<16\n",glopts->num_ancillary_bits);
glopts->num_ancillary_bits = 16;
}
if ((glopts->mode!=TWOLAME_MONO)&&(glopts->num_ancillary_bits<40)) {
fprintf(stderr,"Too few ancillary bits: %i<40\n",glopts->num_ancillary_bits);
glopts->num_ancillary_bits = 40;
}
}
/*
* 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) {
// force stereo mode
twolame_set_mode(glopts, TWOLAME_STEREO);
}
/* don't use padding for VBR */
if (glopts->vbr) {
twolame_set_padding(glopts, FALSE);
}
//MFC FIX: Need to cross validate the number of ancillary_bits
// with the energylevel setting.
//
// energylevel:
// MFC FIX: This option must be mutually exclusive with the
// reservebits(-R) option *UNLESS * the number
// of explicitly reserved bits > 5 bytes.
// If energy information is required, see if we're in MONO mode in
// which case, we only need 16 bits of ancillary data
if (glopts->do_energy_levels) {
if (glopts->mode==TWOLAME_MONO) {
// only 2 bytes needed for energy level for mono channel
twolame_set_num_ancillary_bits(glopts, 16);
} else {
// 5 bytes for the stereo energy info
twolame_set_num_ancillary_bits(glopts, 40);
}
}
// build mpeg header from parameters
if (init_header_info( glopts )<0) {
return -1;
}
// load the alloc tables and do some other stuff
if (init_frame_info( 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;
glopts->crc = 0;
// Allocate memory to larger buffers
glopts->subband = (subband_t *) twolame_malloc (sizeof (subband_t), "subband");
glopts->j_sample = (jsb_sample_t *) twolame_malloc (sizeof (jsb_sample_t), "j_sample");
glopts->sb_sample = (sb_sample_t *) twolame_malloc (sizeof (sb_sample_t), "sb_sample");
// 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);
}