Mercurial > hg > audiostuff
diff spandsp-0.0.3/spandsp-0.0.3/src/playout.c @ 5:f762bf195c4b
import spandsp-0.0.3
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 16:00:21 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/spandsp-0.0.3/spandsp-0.0.3/src/playout.c Fri Jun 25 16:00:21 2010 +0200 @@ -0,0 +1,367 @@ +/* + * SpanDSP - a series of DSP components for telephony + * + * playout.c + * + * Written by Steve Underwood <steveu@coppice.org> + * + * Copyright (C) 2005 Steve Underwood + * + * All rights reserved. + * + * This was kicked off from jitter buffering code + * Copyright (C) 2004, Horizon Wimba, Inc. + * Author Steve Kann <stevek@stevek.com> + * However, there isn't a lot of the original left, now. The original + * was licenced under the LGPL, so any remaining fragments are + * compatible with the GPL licence used here. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * $Id: playout.c,v 1.10 2006/10/24 13:45:26 steveu Exp $ + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <stdio.h> +#include <inttypes.h> +#include <stdlib.h> +#include <string.h> +#include <limits.h> + +#include "spandsp/telephony.h" +#include "spandsp/playout.h" + +static playout_frame_t *queue_get(playout_state_t *s, timestamp_t sender_stamp) +{ + playout_frame_t *frame; + + if ((frame = s->first_frame) == NULL) + return NULL; + + if (sender_stamp >= frame->sender_stamp) + { + /* Remove this frame from the queue */ + if (frame->later) + { + frame->later->earlier = NULL; + s->first_frame = frame->later; + } + else + { + /* The queue is now empty */ + s->first_frame = NULL; + s->last_frame = NULL; + } + return frame; + } + + return NULL; +} +/*- End of function --------------------------------------------------------*/ + +timestamp_t playout_next_due(playout_state_t *s) +{ + return s->last_speech_sender_stamp + s->last_speech_sender_len; +} +/*- End of function --------------------------------------------------------*/ + +timestamp_t playout_current_length(playout_state_t *s) +{ + return s->target_buffer_length; +} +/*- End of function --------------------------------------------------------*/ + +playout_frame_t *playout_get_unconditional(playout_state_t *s) +{ + playout_frame_t *frame; + + if ((frame = queue_get(s, 0x7FFFFFFF))) + { + /* Put it on the free list */ + frame->later = s->free_frames; + s->free_frames = frame; + + /* We return the frame pointer, even though it's on the free list. + The caller *must* copy the data before this frame has any chance + of being reused. */ + } + return frame; +} +/*- End of function --------------------------------------------------------*/ + +int playout_get(playout_state_t *s, playout_frame_t *frameout, timestamp_t now) +{ + playout_frame_t *frame; + + /* Make the last_speech_sender_stamp the current expected one. */ + s->last_speech_sender_stamp += s->last_speech_sender_len; + if ((frame = queue_get(s, s->last_speech_sender_stamp)) == NULL) + { + /* The required frame was not received (or at least not in time) */ + s->frames_missing++; + return PLAYOUT_FILLIN; + } + + if (s->dynamic && frame->type == PLAYOUT_TYPE_SPEECH) + { + /* Assess whether the buffer length is appropriate */ + if (!s->not_first) + { + /* Prime things the first time through */ + s->not_first = TRUE; + s->latest_expected = frame->receiver_stamp + s->min_length; + } + /* Leaky integrate the rate of occurance of frames received just in time and late */ + s->state_late += ((((frame->receiver_stamp > s->latest_expected) ? 0x10000000 : 0) - s->state_late) >> 8); + s->state_just_in_time += ((((frame->receiver_stamp > s->latest_expected - frame->sender_len) ? 0x10000000 : 0) - s->state_just_in_time) >> 8); + s->latest_expected += frame->sender_len; + + if (s->state_late > s->dropable_threshold) + { + if (s->since_last_step < 10) + { + if (s->target_buffer_length < s->max_length - 2) + { + /* The late bin is too big - increase buffering */ + s->target_buffer_length += 3*frame->sender_len; + s->latest_expected += 3*frame->sender_len; + s->state_just_in_time = s->dropable_threshold; + s->state_late = 0; + s->since_last_step = 0; + + s->last_speech_sender_stamp -= 3*s->last_speech_sender_len; + } + } + else + { + if (s->target_buffer_length < s->max_length) + { + /* The late bin is too big - increase buffering */ + s->target_buffer_length += frame->sender_len; + s->latest_expected += frame->sender_len; + s->state_just_in_time = s->dropable_threshold; + s->state_late = 0; + s->since_last_step = 0; + + s->last_speech_sender_stamp -= s->last_speech_sender_len; + } + } + } + else if (s->since_last_step > 500 && s->state_just_in_time < s->dropable_threshold) + { + if (s->target_buffer_length > s->min_length) + { + /* The just-in-time bin is pretty small - decrease buffering */ + s->target_buffer_length -= frame->sender_len; + s->latest_expected -= frame->sender_len; + s->state_just_in_time = s->dropable_threshold; + s->state_late = 0; + s->since_last_step = 0; + + s->last_speech_sender_stamp += s->last_speech_sender_len; + } + } + s->since_last_step++; + } + + /* If its not a speech frame, just return it. */ + if (frame->type != PLAYOUT_TYPE_SPEECH) + { + /* Rewind last_speech_sender_stamp, since this isn't speech */ + s->last_speech_sender_stamp -= s->last_speech_sender_len; + + *frameout = *frame; + /* Put it on the free list */ + frame->later = s->free_frames; + s->free_frames = frame; + + s->frames_out++; + return PLAYOUT_OK; + } + if (frame->sender_stamp < s->last_speech_sender_stamp) + { + /* This speech frame is late */ + *frameout = *frame; + /* Put it on the free list */ + frame->later = s->free_frames; + s->free_frames = frame; + + /* Rewind last_speech_sender_stamp, since we're just dumping */ + s->last_speech_sender_stamp -= s->last_speech_sender_len; + s->frames_out++; + s->frames_late++; + s->frames_missing--; + return PLAYOUT_DROP; + } + /* Keep track of frame sizes, to allow for variable sized frames */ + if (frame->sender_len > 0) + s->last_speech_sender_len = frame->sender_len; + + /* Normal case. Return the frame, and increment stuff */ + *frameout = *frame; + /* Put it on the free list */ + frame->later = s->free_frames; + s->free_frames = frame; + + s->frames_out++; + return PLAYOUT_OK; +} +/*- End of function --------------------------------------------------------*/ + +int playout_put(playout_state_t *s, void *data, int type, timestamp_t sender_len, timestamp_t sender_stamp, timestamp_t receiver_stamp) +{ + playout_frame_t *frame; + playout_frame_t *p; + + /* When a frame arrives we just queue it in order. We leave all the tricky stuff until frames + are read from the queue. */ + s->frames_in++; + + /* Acquire a frame */ + if ((frame = s->free_frames)) + { + s->free_frames = frame->later; + } + else + { + if ((frame = (playout_frame_t *) malloc(sizeof(playout_frame_t))) == NULL) + return PLAYOUT_ERROR; + } + + /* Fill out the frame */ + frame->data = data; + frame->type = type; + frame->sender_stamp = sender_stamp; + frame->sender_len = sender_len; + frame->receiver_stamp = receiver_stamp; + + /* Frames are kept in a list, sorted by the timestamp assigned by the sender. */ + if (s->last_frame == NULL) + { + /* The queue is empty. */ + frame->later = NULL; + frame->earlier = NULL; + s->first_frame = frame; + s->last_frame = frame; + } + else if (sender_stamp >= s->last_frame->sender_stamp) + { + /* Frame goes at the end of the queue. */ + frame->later = NULL; + frame->earlier = s->last_frame; + s->last_frame->later = frame; + s->last_frame = frame; + } + else + { + /* Frame is out of sequence. */ + s->frames_oos++; + + /* Find where it should go in the queue */ + p = s->last_frame; + while (sender_stamp < p->sender_stamp && p->earlier) + p = p->earlier; + + if (p->earlier) + { + /* It needs to go somewhere in the queue */ + frame->later = p->later; + frame->earlier = p; + p->later->earlier = frame; + p->later = frame; + } + else + { + /* It needs to go at the very beginning of the queue */ + frame->later = p; + frame->earlier = NULL; + p->earlier = frame; + s->first_frame = frame; + } + } + + if (s->start && type == PLAYOUT_TYPE_SPEECH) + { + s->last_speech_sender_stamp = sender_stamp - sender_len - s->min_length; + s->last_speech_sender_len = sender_len; + s->start = FALSE; + } + + return PLAYOUT_OK; +} +/*- End of function --------------------------------------------------------*/ + +void playout_restart(playout_state_t *s, int min_length, int max_length) +{ + playout_frame_t *frame; + playout_frame_t *next; + + /* Free all the frames on the free list */ + for (frame = s->free_frames; frame; frame = next) + { + next = frame->later; + free(frame); + } + + memset(s, 0, sizeof(*s)); + s->dynamic = (min_length < max_length); + s->min_length = min_length; + s->max_length = (max_length > min_length) ? max_length : min_length; + s->dropable_threshold = 1*0x10000000/100; + s->start = TRUE; + s->since_last_step = 0x7FFFFFFF; + /* Start with the minimum buffer length allowed, and work from there */ + s->actual_buffer_length = + s->target_buffer_length = (s->max_length - s->min_length)/2; +} +/*- End of function --------------------------------------------------------*/ + +playout_state_t *playout_new(int min_length, int max_length) +{ + playout_state_t *s; + + if ((s = (playout_state_t *) malloc(sizeof(playout_state_t))) == NULL) + return NULL; + memset(s, 0, sizeof(*s)); + playout_restart(s, min_length, max_length); + return s; +} +/*- End of function --------------------------------------------------------*/ + +void playout_free(playout_state_t *s) +{ + playout_frame_t *frame; + playout_frame_t *next; + + /* Free all the frames in the queue. In most cases these should have been + removed already, so their associated data could be freed. */ + for (frame = s->first_frame; frame; frame = next) + { + next = frame->later; + free(frame); + } + /* Free all the frames on the free list */ + for (frame = s->free_frames; frame; frame = next) + { + next = frame->later; + free(frame); + } + /* Finally, free ourselves! */ + free(s); +} +/*- End of function --------------------------------------------------------*/ +/*- End of file ------------------------------------------------------------*/