slinfactory.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Anthony Minessale II.
 *
 * Anthony Minessale <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief A machine to gather up arbitrary frames and convert them
 * to raw slinear on demand.
 *
 * \author Anthony Minessale <[email protected]>
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/frame.h"
#include "asterisk/format_cache.h"
#include "asterisk/slinfactory.h"
#include "asterisk/translate.h"
#include "asterisk/astobj2.h"

void ast_slinfactory_init(struct ast_slinfactory *sf)
{
 memset(sf, 0, sizeof(*sf));
 sf->offset = sf->hold;
 sf->output_format = ao2_bump(ast_format_slin);
}

int ast_slinfactory_init_with_format(struct ast_slinfactory *sf, struct ast_format *slin_out)
{
 memset(sf, 0, sizeof(*sf));
 sf->offset = sf->hold;
 if (!ast_format_cache_is_slinear(slin_out)) {
 return -1;
 }
 sf->output_format = ao2_bump(slin_out);

 return 0;
}

void ast_slinfactory_destroy(struct ast_slinfactory *sf)
{
 struct ast_frame *f;

 if (sf->trans) {
 ast_translator_free_path(sf->trans);
 sf->trans = NULL;
 }

 while ((f = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list))) {
 ast_frfree(f);
 }

 ao2_cleanup(sf->output_format);
 sf->output_format = NULL;
 ao2_cleanup(sf->format);
 sf->format = NULL;
}

int ast_slinfactory_feed(struct ast_slinfactory *sf, struct ast_frame *f)
{
 struct ast_frame *begin_frame = f, *duped_frame = NULL, *frame_ptr;
 unsigned int x = 0;

 /* In some cases, we can be passed a frame which has no data in it, but
 * which has a positive number of samples defined. Once such situation is
 * when a jitter buffer is in use and the jitter buffer interpolates a frame.
 * The frame it produces has data set to NULL, datalen set to 0, and samples
 * set to either 160 or 240.
 */
 if (!f->data.ptr) {
 return 0;
 }

 if (ast_format_cmp(f->subclass.format, sf->output_format) == AST_FORMAT_CMP_NOT_EQUAL) {
 if (sf->trans && (ast_format_cmp(f->subclass.format, sf->format) == AST_FORMAT_CMP_NOT_EQUAL)) {
 ast_translator_free_path(sf->trans);
 sf->trans = NULL;
 }

 if (!sf->trans) {
 if (!(sf->trans = ast_translator_build_path(sf->output_format, f->subclass.format))) {
 ast_log(LOG_WARNING, "Cannot build a path from %s (%u)to %s (%u)\n",
 ast_format_get_name(f->subclass.format),
 ast_format_get_codec_id(f->subclass.format),
 ast_format_get_name(sf->output_format),
 ast_format_get_codec_id(sf->output_format));
 return 0;
 }
 ao2_replace(sf->format, f->subclass.format);
 }

 if (!(begin_frame = ast_translate(sf->trans, f, 0))) {
 return 0;
 }

 if (!(duped_frame = ast_frisolate(begin_frame))) {
 return 0;
 }

 if (duped_frame != begin_frame) {
 ast_frfree(begin_frame);
 }
 } else {
 if (sf->trans) {
 ast_translator_free_path(sf->trans);
 sf->trans = NULL;
 }
 if (!(duped_frame = ast_frdup(f)))
 return 0;
 }

 AST_LIST_TRAVERSE(&sf->queue, frame_ptr, frame_list) {
 x++;
 }

 /* if the frame was translated, the translator may have returned multiple
 frames, so process each of them
 */
 for (begin_frame = duped_frame; begin_frame; begin_frame = AST_LIST_NEXT(begin_frame, frame_list)) {
 AST_LIST_INSERT_TAIL(&sf->queue, begin_frame, frame_list);
 sf->size += begin_frame->samples;
 }

 return x;
}

int ast_slinfactory_read(struct ast_slinfactory *sf, short *buf, size_t samples)
{
 struct ast_frame *frame_ptr;
 unsigned int sofar = 0, ineed, remain;
 short *frame_data, *offset = buf;

 while (sofar < samples) {
 ineed = samples - sofar;

 if (sf->holdlen) {
 if (sf->holdlen <= ineed) {
 memcpy(offset, sf->offset, sf->holdlen * sizeof(*offset));
 sofar += sf->holdlen;
 offset += sf->holdlen;
 sf->holdlen = 0;
 sf->offset = sf->hold;
 } else {
 remain = sf->holdlen - ineed;
 memcpy(offset, sf->offset, ineed * sizeof(*offset));
 sofar += ineed;
 sf->offset += ineed;
 sf->holdlen = remain;
 }
 continue;
 }

 if ((frame_ptr = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list))) {
 frame_data = frame_ptr->data.ptr;

 if (frame_ptr->samples <= ineed) {
 memcpy(offset, frame_data, frame_ptr->samples * sizeof(*offset));
 sofar += frame_ptr->samples;
 offset += frame_ptr->samples;
 } else {
 remain = frame_ptr->samples - ineed;
 memcpy(offset, frame_data, ineed * sizeof(*offset));
 sofar += ineed;
 frame_data += ineed;
 if (remain > (AST_SLINFACTORY_MAX_HOLD - sf->holdlen)) {
 remain = AST_SLINFACTORY_MAX_HOLD - sf->holdlen;
 }
 memcpy(sf->hold, frame_data, remain * sizeof(*offset));
 sf->holdlen = remain;
 }
 ast_frfree(frame_ptr);
 } else {
 break;
 }
 }

 sf->size -= sofar;
 return sofar;
}

unsigned int ast_slinfactory_available(const struct ast_slinfactory *sf)
{
 return sf->size;
}

void ast_slinfactory_flush(struct ast_slinfactory *sf)
{
 struct ast_frame *fr = NULL;

 if (sf->trans) {
 ast_translator_free_path(sf->trans);
 sf->trans = NULL;
 }

 while ((fr = AST_LIST_REMOVE_HEAD(&sf->queue, frame_list)))
 ast_frfree(fr);

 sf->size = sf->holdlen = 0;
 sf->offset = sf->hold;

 return;
}