Translate between signed linear and LPC10 (Linear Predictor Code) More...

#include "asterisk.h"
#include "asterisk/translate.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/utils.h"
#include "asterisk/linkedlists.h"
#include "lpc10/lpc10.h"
#include "asterisk/slin.h"
#include "ex_lpc10.h"

Include dependency graph for codec_lpc10.c:

Go to the source code of this file.

Data Structures
struct	lpc10_coder_pvt

Macros
#define	BUFFER_SAMPLES 8000

#define	LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8

Functions
static void	__reg_module (void)

static void	__unreg_module (void)

struct ast_module *	AST_MODULE_SELF_SYM (void)

static void	build_bits (unsigned char c, INT32 bits)

static void	extract_bits (INT32 bits, unsigned char c)

static int	lintolpc10_framein (struct ast_trans_pvt pvt, struct ast_frame f)

static struct ast_frame *	lintolpc10_frameout (struct ast_trans_pvt *pvt)

static int	load_module (void)

static int	lpc10_dec_new (struct ast_trans_pvt *pvt)

static void	lpc10_destroy (struct ast_trans_pvt *arg)

static int	lpc10_enc_new (struct ast_trans_pvt *pvt)

static int	lpc10tolin_framein (struct ast_trans_pvt pvt, struct ast_frame f)

static int	unload_module (void)

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "LPC10 2.4kbps Coder/Decoder" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, }

static const struct ast_module_info *	ast_module_info = &__mod_info

static struct ast_translator	lintolpc10

static struct ast_translator	lpc10tolin

Detailed Description

Translate between signed linear and LPC10 (Linear Predictor Code)

Definition in file codec_lpc10.c.

Macro Definition Documentation

◆ BUFFER_SAMPLES

#define BUFFER_SAMPLES 8000

Definition at line 55 of file codec_lpc10.c.

◆ LPC10_BYTES_IN_COMPRESSED_FRAME

#define LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8

Definition at line 53 of file codec_lpc10.c.

Function Documentation

◆ __reg_module()

static void __reg_module ( void )

static

Definition at line 285 of file codec_lpc10.c.

◆ __unreg_module()

static void __unreg_module ( void )

static

Definition at line 285 of file codec_lpc10.c.

◆ AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM ( void )

Definition at line 285 of file codec_lpc10.c.

◆ build_bits()

static void build_bits	(	unsigned char *	c,
		INT32 *	bits
	)

static

Definition at line 95 of file codec_lpc10.c.

{
    unsigned char mask=0x80;
    int x;
    *c = 0;
    for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
        if (bits[x])
            *c |= mask;
        mask = mask >> 1;
        if ((x % 8)==7) {
            c++;
            *c = 0;
            mask = 0x80;
        }
    }
}

References c, and LPC10_BITS_IN_COMPRESSED_FRAME.

Referenced by lintolpc10_frameout().

◆ extract_bits()

static void extract_bits	(	INT32 *	bits,
		unsigned char *	c
	)

static

Definition at line 81 of file codec_lpc10.c.

{
    int x;
    for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
        if (*c & (0x80 >> (x & 7)))
            bits[x] = 1;
        else
            bits[x] = 0;
        if ((x & 7) == 7)
            c++;
    }
}

References c, and LPC10_BITS_IN_COMPRESSED_FRAME.

Referenced by lpc10tolin_framein().

◆ lintolpc10_framein()

static int lintolpc10_framein	(	struct ast_trans_pvt *	pvt,
		struct ast_frame *	f
	)

static

Definition at line 145 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *tmp = pvt->pvt;
 
    /* Just add the frames to our stream */
    if (pvt->samples + f->samples > BUFFER_SAMPLES) {
        ast_log(LOG_WARNING, "Out of buffer space\n");
        return -1;
    }
    memcpy(tmp->buf + pvt->samples, f->data.ptr, f->datalen);
    pvt->samples += f->samples;
    return 0;
}

References ast_log, lpc10_coder_pvt::buf, BUFFER_SAMPLES, ast_frame::data, ast_frame::datalen, LOG_WARNING, ast_frame::ptr, ast_trans_pvt::pvt, ast_frame::samples, and ast_trans_pvt::samples.

◆ lintolpc10_frameout()

static struct ast_frame * lintolpc10_frameout ( struct ast_trans_pvt * pvt )

static

Definition at line 159 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *tmp = pvt->pvt;
    struct ast_frame *result = NULL;
    struct ast_frame *last = NULL;
    int samples = 0; /* output samples */
 
    while (pvt->samples >= LPC10_SAMPLES_PER_FRAME) {
        struct ast_frame *current;
        float tmpbuf[LPC10_SAMPLES_PER_FRAME];
        INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX what ??? */
        int x;
 
        /* Encode a frame of data */
        for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++)
            tmpbuf[x] = (float)tmp->buf[x + samples] / 32768.0;
        lpc10_encode(tmpbuf, bits, tmp->lpc10.enc);
        build_bits(pvt->outbuf.uc, bits);
 
        samples += LPC10_SAMPLES_PER_FRAME;
        pvt->samples -= LPC10_SAMPLES_PER_FRAME;
        /* Use one of the two left over bits to record if this is a 22 or 23 ms frame...
           important for IAX use */
        tmp->longer = 1 - tmp->longer;
 
        current = ast_trans_frameout(pvt, LPC10_BYTES_IN_COMPRESSED_FRAME, LPC10_SAMPLES_PER_FRAME);
        if (!current) {
            continue;
        } else if (last) {
            AST_LIST_NEXT(last, frame_list) = current;
        } else {
            result = current;
        }
        last = current;
    }
 
    /* Move the data at the end of the buffer to the front */
    if (samples) {
        memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
    }
 
    return result;
}

References AST_LIST_NEXT, ast_trans_frameout(), lpc10_coder_pvt::buf, build_bits(), current, lpc10_coder_pvt::enc, last, lpc10_coder_pvt::longer, lpc10_coder_pvt::lpc10, LPC10_BITS_IN_COMPRESSED_FRAME, LPC10_BYTES_IN_COMPRESSED_FRAME, lpc10_encode(), LPC10_SAMPLES_PER_FRAME, NULL, ast_trans_pvt::outbuf, ast_trans_pvt::pvt, result, ast_frame::samples, ast_trans_pvt::samples, and ast_trans_pvt::uc.

◆ load_module()

static int load_module ( void )

static

Definition at line 266 of file codec_lpc10.c.

{
    int res;
 
    res = ast_register_translator(&lpc10tolin);
    res |= ast_register_translator(&lintolpc10);
 
    if (res) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}

References AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, ast_register_translator, lintolpc10, lpc10tolin, and unload_module().

◆ lpc10_dec_new()

static int lpc10_dec_new ( struct ast_trans_pvt * pvt )

static

Definition at line 74 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *tmp = pvt->pvt;
 
    return (tmp->lpc10.dec = create_lpc10_decoder_state()) ? 0 : -1;
}

References create_lpc10_decoder_state(), lpc10_coder_pvt::dec, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

◆ lpc10_destroy()

static void lpc10_destroy ( struct ast_trans_pvt * arg )

static

Definition at line 204 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *pvt = arg->pvt;
    /* Enc and DEC are both just allocated, so they can be freed */
    ast_free(pvt->lpc10.enc);
}

References ast_free, lpc10_coder_pvt::enc, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

◆ lpc10_enc_new()

static int lpc10_enc_new ( struct ast_trans_pvt * pvt )

static

Definition at line 67 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *tmp = pvt->pvt;
 
    return (tmp->lpc10.enc = create_lpc10_encoder_state()) ? 0 : -1;
}

References create_lpc10_encoder_state(), lpc10_coder_pvt::enc, lpc10_coder_pvt::lpc10, and ast_trans_pvt::pvt.

◆ lpc10tolin_framein()

static int lpc10tolin_framein	(	struct ast_trans_pvt *	pvt,
		struct ast_frame *	f
	)

static

Definition at line 112 of file codec_lpc10.c.

{
    struct lpc10_coder_pvt *tmp = pvt->pvt;
    int16_t *dst = pvt->outbuf.i16;
    int len = 0;
 
    while (len + LPC10_BYTES_IN_COMPRESSED_FRAME <= f->datalen) {
        int x;
        float tmpbuf[LPC10_SAMPLES_PER_FRAME];
        INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX see note */
        if (pvt->samples + LPC10_SAMPLES_PER_FRAME > BUFFER_SAMPLES) {
            ast_log(LOG_WARNING, "Out of buffer space\n");
            return -1;
        }
        extract_bits(bits, f->data.ptr + len);
        if (lpc10_decode(bits, tmpbuf, tmp->lpc10.dec)) {
            ast_log(LOG_WARNING, "Invalid lpc10 data\n");
            return -1;
        }
        for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++) {
            /* Convert to a short between -1.0 and 1.0 */
            dst[pvt->samples + x] = (int16_t)(32768.0 * tmpbuf[x]);
        }
 
        pvt->samples += LPC10_SAMPLES_PER_FRAME;
        pvt->datalen += 2*LPC10_SAMPLES_PER_FRAME;
        len += LPC10_BYTES_IN_COMPRESSED_FRAME;
    }
    if (len != f->datalen)
        printf("Decoded %d, expected %d\n", len, f->datalen);
    return 0;
}

References ast_log, BUFFER_SAMPLES, ast_frame::data, ast_frame::datalen, ast_trans_pvt::datalen, lpc10_coder_pvt::dec, extract_bits(), ast_trans_pvt::i16, len(), LOG_WARNING, lpc10_coder_pvt::lpc10, LPC10_BITS_IN_COMPRESSED_FRAME, LPC10_BYTES_IN_COMPRESSED_FRAME, lpc10_decode(), LPC10_SAMPLES_PER_FRAME, ast_trans_pvt::outbuf, ast_frame::ptr, ast_trans_pvt::pvt, and ast_trans_pvt::samples.

◆ unload_module()

static int unload_module ( void )

static

Definition at line 256 of file codec_lpc10.c.

{
    int res;
 
    res = ast_unregister_translator(&lintolpc10);
    res |= ast_unregister_translator(&lpc10tolin);
 
    return res;
}

References ast_unregister_translator(), lintolpc10, and lpc10tolin.

Referenced by load_module().

Variable Documentation

◆ __mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "LPC10 2.4kbps Coder/Decoder" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, }

static

Definition at line 285 of file codec_lpc10.c.

◆ ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 285 of file codec_lpc10.c.

◆ lintolpc10

struct ast_translator lintolpc10

static

Definition at line 233 of file codec_lpc10.c.

                                          {
    .name = "lintolpc10",
    .src_codec = {
        .name = "slin",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .dst_codec = {
        .name = "lpc10",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .format = "lpc10",
    .newpvt = lpc10_enc_new,
    .framein = lintolpc10_framein,
    .frameout = lintolpc10_frameout,
    .destroy = lpc10_destroy,
    .sample = slin8_sample,
    .desc_size = sizeof(struct lpc10_coder_pvt),
    .buffer_samples = BUFFER_SAMPLES,
    .buf_size = LPC10_BYTES_IN_COMPRESSED_FRAME * (1 + BUFFER_SAMPLES / LPC10_SAMPLES_PER_FRAME),
};

Referenced by load_module(), and unload_module().

◆ lpc10tolin

struct ast_translator lpc10tolin

static

Definition at line 211 of file codec_lpc10.c.

                                          {
    .name = "lpc10tolin",
    .src_codec = {
        .name = "lpc10",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .dst_codec = {
        .name = "slin",
        .type = AST_MEDIA_TYPE_AUDIO,
        .sample_rate = 8000,
    },
    .format = "slin",
    .newpvt = lpc10_dec_new,
    .framein = lpc10tolin_framein,
    .destroy = lpc10_destroy,
    .sample = lpc10_sample,
    .desc_size = sizeof(struct lpc10_coder_pvt),
    .buffer_samples = BUFFER_SAMPLES,
    .buf_size = BUFFER_SAMPLES * 2,
};

Referenced by load_module(), and unload_module().

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ BUFFER_SAMPLES

◆ LPC10_BYTES_IN_COMPRESSED_FRAME

Function Documentation

◆ __reg_module()

◆ __unreg_module()

◆ AST_MODULE_SELF_SYM()

◆ build_bits()

◆ extract_bits()

◆ lintolpc10_framein()

◆ lintolpc10_frameout()

◆ load_module()

◆ lpc10_dec_new()

◆ lpc10_destroy()

◆ lpc10_enc_new()

◆ lpc10tolin_framein()

◆ unload_module()

Variable Documentation

◆ __mod_info

◆ ast_module_info

◆ lintolpc10

◆ lpc10tolin