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Diffstat (limited to 'src/libspeex/jitter.c')
| -rw-r--r-- | src/libspeex/jitter.c | 840 |
1 files changed, 840 insertions, 0 deletions
diff --git a/src/libspeex/jitter.c b/src/libspeex/jitter.c new file mode 100644 index 00000000..6a32e754 --- /dev/null +++ b/src/libspeex/jitter.c @@ -0,0 +1,840 @@ +/* Copyright (C) 2002 Jean-Marc Valin + File: speex_jitter.h + + Adaptive jitter buffer for Speex + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + - Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + - Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + - Neither the name of the Xiph.org Foundation nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR + CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +*/ + +/* +TODO: +- Add short-term estimate +- Defensive programming + + warn when last returned < last desired (begative buffering) + + warn if update_delay not called between get() and tick() or is called twice in a row +- Linked list structure for holding the packets instead of the current fixed-size array + + return memory to a pool + + allow pre-allocation of the pool + + optional max number of elements +- Statistics + + drift + + loss + + late + + jitter + + buffering delay +*/ +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + + +#include "arch.h" +#include <speex/speex.h> +#include <speex/speex_bits.h> +#include <speex/speex_jitter.h> +#include "os_support.h" + +#ifndef NULL +#define NULL 0 +#endif + +#define SPEEX_JITTER_MAX_BUFFER_SIZE 200 /**< Maximum number of packets in jitter buffer */ + +#define TSUB(a,b) ((spx_int32_t)((a)-(b))) + +#define GT32(a,b) (((spx_int32_t)((a)-(b)))>0) +#define GE32(a,b) (((spx_int32_t)((a)-(b)))>=0) +#define LT32(a,b) (((spx_int32_t)((a)-(b)))<0) +#define LE32(a,b) (((spx_int32_t)((a)-(b)))<=0) + +#define ROUND_DOWN(x, step) ((x)<0 ? ((x)-(step)+1)/(step)*(step) : (x)/(step)*(step)) + +#define MAX_TIMINGS 20 +#define MAX_BUFFERS 3 +#define TOP_DELAY 20 + +/** Buffer that keeps the time of arrival of the latest packets */ +struct TimingBuffer { + int filled; /**< Number of entries occupied in "timing" and "counts"*/ + int curr_count; /**< Number of packet timings we got (including those we discarded) */ + spx_int16_t timing[MAX_TIMINGS]; /**< Sorted list of all timings ("latest" packets first) */ + spx_int16_t counts[MAX_TIMINGS]; /**< Order the packets were put in (will be used for short-term estimate) */ +}; + +static void tb_init(struct TimingBuffer *tb) +{ + tb->filled = 0; + tb->curr_count = 0; +} + +/* Add the timing of a new packet to the TimingBuffer */ +static void tb_add(struct TimingBuffer *tb, spx_int16_t timing) +{ + int pos; + /* Discard packet that won't make it into the list because they're too early */ + if (tb->filled >= MAX_TIMINGS && timing >= tb->timing[tb->filled-1]) + { + tb->curr_count++; + return; + } + + /* Find where the timing info goes in the sorted list */ + pos = 0; + /* FIXME: Do bisection instead of linear search */ + while (pos<tb->filled && timing >= tb->timing[pos]) + { + pos++; + } + + speex_assert(pos <= tb->filled && pos < MAX_TIMINGS); + + /* Shift everything so we can perform the insertion */ + if (pos < tb->filled) + { + int move_size = tb->filled-pos; + if (tb->filled == MAX_TIMINGS) + move_size -= 1; + SPEEX_MOVE(&tb->timing[pos+1], &tb->timing[pos], move_size); + SPEEX_MOVE(&tb->counts[pos+1], &tb->counts[pos], move_size); + } + /* Insert */ + tb->timing[pos] = timing; + tb->counts[pos] = tb->curr_count; + + tb->curr_count++; + if (tb->filled<MAX_TIMINGS) + tb->filled++; +} + + + +/** Jitter buffer structure */ +struct JitterBuffer_ { + spx_uint32_t pointer_timestamp; /**< Timestamp of what we will *get* next */ + spx_uint32_t last_returned_timestamp; /**< Useful for getting the next packet with the same timestamp (for fragmented media) */ + spx_uint32_t next_stop; /**< Estimated time the next get() will be called */ + + spx_int32_t buffered; /**< Amount of data we think is still buffered by the application (timestamp units)*/ + + JitterBufferPacket packets[SPEEX_JITTER_MAX_BUFFER_SIZE]; /**< Packets stored in the buffer */ + spx_uint32_t arrival[SPEEX_JITTER_MAX_BUFFER_SIZE]; /**< Packet arrival time (0 means it was late, even though it's a valid timestamp) */ + + void (*destroy) (void *); /**< Callback for destroying a packet */ + + spx_int32_t delay_step; /**< Size of the steps when adjusting buffering (timestamp units) */ + spx_int32_t concealment_size; /**< Size of the packet loss concealment "units" */ + int reset_state; /**< True if state was just reset */ + int buffer_margin; /**< How many frames we want to keep in the buffer (lower bound) */ + int late_cutoff; /**< How late must a packet be for it not to be considered at all */ + int interp_requested; /**< An interpolation is requested by speex_jitter_update_delay() */ + int auto_adjust; /**< Whether to automatically adjust the delay at any time */ + + struct TimingBuffer _tb[MAX_BUFFERS]; /**< Don't use those directly */ + struct TimingBuffer *timeBuffers[MAX_BUFFERS]; /**< Storing arrival time of latest frames so we can compute some stats */ + int window_size; /**< Total window over which the late frames are counted */ + int subwindow_size; /**< Sub-window size for faster computation */ + int max_late_rate; /**< Absolute maximum amount of late packets tolerable (in percent) */ + int latency_tradeoff; /**< Latency equivalent of losing one percent of packets */ + int auto_tradeoff; /**< Latency equivalent of losing one percent of packets (automatic default) */ + + int lost_count; /**< Number of consecutive lost packets */ +}; + +/** Based on available data, this computes the optimal delay for the jitter buffer. + The optimised function is in timestamp units and is: + cost = delay + late_factor*[number of frames that would be late if we used that delay] + @param tb Array of buffers + @param late_factor Equivalent cost of a late frame (in timestamp units) + */ +static spx_int16_t compute_opt_delay(JitterBuffer *jitter) +{ + int i; + spx_int16_t opt=0; + spx_int32_t best_cost=0x7fffffff; + int late = 0; + int pos[MAX_BUFFERS]; + int tot_count; + float late_factor; + int penalty_taken = 0; + int best = 0; + int worst = 0; + spx_int32_t deltaT; + struct TimingBuffer *tb; + + tb = jitter->_tb; + + /* Number of packet timings we have received (including those we didn't keep) */ + tot_count = 0; + for (i=0;i<MAX_BUFFERS;i++) + tot_count += tb[i].curr_count; + if (tot_count==0) + return 0; + + /* Compute cost for one lost packet */ + if (jitter->latency_tradeoff != 0) + late_factor = jitter->latency_tradeoff * 100.0f / tot_count; + else + late_factor = jitter->auto_tradeoff * jitter->window_size/tot_count; + + /*fprintf(stderr, "late_factor = %f\n", late_factor);*/ + for (i=0;i<MAX_BUFFERS;i++) + pos[i] = 0; + + /* Pick the TOP_DELAY "latest" packets (doesn't need to actually be late + for the current settings) */ + for (i=0;i<TOP_DELAY;i++) + { + int j; + int next=-1; + int latest = 32767; + /* Pick latest amoung all sub-windows */ + for (j=0;j<MAX_BUFFERS;j++) + { + if (pos[j] < tb[j].filled && tb[j].timing[pos[j]] < latest) + { + next = j; + latest = tb[j].timing[pos[j]]; + } + } + if (next != -1) + { + spx_int32_t cost; + + if (i==0) + worst = latest; + best = latest; + latest = ROUND_DOWN(latest, jitter->delay_step); + pos[next]++; + + /* Actual cost function that tells us how bad using this delay would be */ + cost = -latest + late_factor*late; + /*fprintf(stderr, "cost %d = %d + %f * %d\n", cost, -latest, late_factor, late);*/ + if (cost < best_cost) + { + best_cost = cost; + opt = latest; + } + } else { + break; + } + + /* For the next timing we will consider, there will be one more late packet to count */ + late++; + /* Two-frame penalty if we're going to increase the amount of late frames (hysteresis) */ + if (latest >= 0 && !penalty_taken) + { + penalty_taken = 1; + late+=2; + } + } + + deltaT = best-worst; + /* This is a default "automatic latency tradeoff" when none is provided */ + jitter->auto_tradeoff = 1 + deltaT/TOP_DELAY; + /*fprintf(stderr, "auto_tradeoff = %d (%d %d %d)\n", jitter->auto_tradeoff, best, worst, i);*/ + + /* FIXME: Compute a short-term estimate too and combine with the long-term one */ + + /* Prevents reducing the buffer size when we haven't really had much data */ + if (tot_count < TOP_DELAY && opt > 0) + return 0; + return opt; +} + + +/** Initialise jitter buffer */ +JitterBuffer *jitter_buffer_init(int step_size) +{ + JitterBuffer *jitter = (JitterBuffer*)speex_alloc(sizeof(JitterBuffer)); + if (jitter) + { + int i; + spx_int32_t tmp; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + jitter->packets[i].data=NULL; + jitter->delay_step = step_size; + jitter->concealment_size = step_size; + /*FIXME: Should this be 0 or 1?*/ + jitter->buffer_margin = 0; + jitter->late_cutoff = 50; + jitter->destroy = NULL; + jitter->latency_tradeoff = 0; + jitter->auto_adjust = 1; + tmp = 4; + jitter_buffer_ctl(jitter, JITTER_BUFFER_SET_MAX_LATE_RATE, &tmp); + jitter_buffer_reset(jitter); + } + return jitter; +} + +/** Reset jitter buffer */ +void jitter_buffer_reset(JitterBuffer *jitter) +{ + int i; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data) + { + if (jitter->destroy) + jitter->destroy(jitter->packets[i].data); + else + speex_free(jitter->packets[i].data); + jitter->packets[i].data = NULL; + } + } + /* Timestamp is actually undefined at this point */ + jitter->pointer_timestamp = 0; + jitter->next_stop = 0; + jitter->reset_state = 1; + jitter->lost_count = 0; + jitter->buffered = 0; + jitter->auto_tradeoff = 32000; + + for (i=0;i<MAX_BUFFERS;i++) + { + tb_init(&jitter->_tb[i]); + jitter->timeBuffers[i] = &jitter->_tb[i]; + } + /*fprintf (stderr, "reset\n");*/ +} + +/** Destroy jitter buffer */ +void jitter_buffer_destroy(JitterBuffer *jitter) +{ + jitter_buffer_reset(jitter); + speex_free(jitter); +} + +/** Take the following timing into consideration for future calculations */ +static void update_timings(JitterBuffer *jitter, spx_int32_t timing) +{ + if (timing < -32767) + timing = -32767; + if (timing > 32767) + timing = 32767; + /* If the current sub-window is full, perform a rotation and discard oldest sub-widow */ + if (jitter->timeBuffers[0]->curr_count >= jitter->subwindow_size) + { + int i; + /*fprintf(stderr, "Rotate buffer\n");*/ + struct TimingBuffer *tmp = jitter->timeBuffers[MAX_BUFFERS-1]; + for (i=MAX_BUFFERS-1;i>=1;i--) + jitter->timeBuffers[i] = jitter->timeBuffers[i-1]; + jitter->timeBuffers[0] = tmp; + tb_init(jitter->timeBuffers[0]); + } + tb_add(jitter->timeBuffers[0], timing); +} + +/** Compensate all timings when we do an adjustment of the buffering */ +static void shift_timings(JitterBuffer *jitter, spx_int16_t amount) +{ + int i, j; + for (i=0;i<MAX_BUFFERS;i++) + { + for (j=0;j<jitter->timeBuffers[i]->filled;j++) + jitter->timeBuffers[i]->timing[j] += amount; + } +} + + +/** Put one packet into the jitter buffer */ +void jitter_buffer_put(JitterBuffer *jitter, const JitterBufferPacket *packet) +{ + int i,j; + int late; + /*fprintf (stderr, "put packet %d %d\n", timestamp, span);*/ + + /* Cleanup buffer (remove old packets that weren't played) */ + if (!jitter->reset_state) + { + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + /* Make sure we don't discard a "just-late" packet in case we want to play it next (if we interpolate). */ + if (jitter->packets[i].data && LE32(jitter->packets[i].timestamp + jitter->packets[i].span, jitter->pointer_timestamp)) + { + /*fprintf (stderr, "cleaned (not played)\n");*/ + if (jitter->destroy) + jitter->destroy(jitter->packets[i].data); + else + speex_free(jitter->packets[i].data); + jitter->packets[i].data = NULL; + } + } + } + + /*fprintf(stderr, "arrival: %d %d %d\n", packet->timestamp, jitter->next_stop, jitter->pointer_timestamp);*/ + /* Check if packet is late (could still be useful though) */ + if (!jitter->reset_state && LT32(packet->timestamp, jitter->next_stop)) + { + update_timings(jitter, ((spx_int32_t)packet->timestamp) - ((spx_int32_t)jitter->next_stop) - jitter->buffer_margin); + late = 1; + } else { + late = 0; + } + + /* Only insert the packet if it's not hopelessly late (i.e. totally useless) */ + if (jitter->reset_state || GE32(packet->timestamp+packet->span+jitter->delay_step, jitter->pointer_timestamp)) + { + + /*Find an empty slot in the buffer*/ + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data==NULL) + break; + } + + /*No place left in the buffer, need to make room for it by discarding the oldest packet */ + if (i==SPEEX_JITTER_MAX_BUFFER_SIZE) + { + int earliest=jitter->packets[0].timestamp; + i=0; + for (j=1;j<SPEEX_JITTER_MAX_BUFFER_SIZE;j++) + { + if (!jitter->packets[i].data || LT32(jitter->packets[j].timestamp,earliest)) + { + earliest = jitter->packets[j].timestamp; + i=j; + } + } + if (jitter->destroy) + jitter->destroy(jitter->packets[i].data); + else + speex_free(jitter->packets[i].data); + jitter->packets[i].data=NULL; + if (jitter->lost_count>20) + { + jitter_buffer_reset(jitter); + } + /*fprintf (stderr, "Buffer is full, discarding earliest frame %d (currently at %d)\n", timestamp, jitter->pointer_timestamp);*/ + } + + /* Copy packet in buffer */ + if (jitter->destroy) + { + jitter->packets[i].data = packet->data; + } else { + jitter->packets[i].data=(char*)speex_alloc(packet->len); + for (j=0;j<packet->len;j++) + jitter->packets[i].data[j]=packet->data[j]; + } + jitter->packets[i].timestamp=packet->timestamp; + jitter->packets[i].span=packet->span; + jitter->packets[i].len=packet->len; + jitter->packets[i].sequence=packet->sequence; + jitter->packets[i].user_data=packet->user_data; + if (jitter->reset_state || late) + jitter->arrival[i] = 0; + else + jitter->arrival[i] = jitter->next_stop; + } + + +} + +/** Get one packet from the jitter buffer */ +int jitter_buffer_get(JitterBuffer *jitter, JitterBufferPacket *packet, spx_int32_t desired_span, spx_int32_t *start_offset) +{ + int i; + unsigned int j; + int incomplete = 0; + spx_int16_t opt; + + if (start_offset != NULL) + *start_offset = 0; + + /* Syncing on the first call */ + if (jitter->reset_state) + { + int found = 0; + /* Find the oldest packet */ + spx_uint32_t oldest=0; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && (!found || LT32(jitter->packets[i].timestamp,oldest))) + { + oldest = jitter->packets[i].timestamp; + found = 1; + } + } + if (found) + { + jitter->reset_state=0; + jitter->pointer_timestamp = oldest; + jitter->next_stop = oldest; + } else { + packet->timestamp = 0; + packet->span = jitter->interp_requested; + return JITTER_BUFFER_MISSING; + } + } + + + jitter->last_returned_timestamp = jitter->pointer_timestamp; + + if (jitter->interp_requested != 0) + { + packet->timestamp = jitter->pointer_timestamp; + packet->span = jitter->interp_requested; + + /* Increment the pointer because it got decremented in the delay update */ + jitter->pointer_timestamp += jitter->interp_requested; + packet->len = 0; + /*fprintf (stderr, "Deferred interpolate\n");*/ + + jitter->interp_requested = 0; + + jitter->buffered = packet->span - desired_span; + + return JITTER_BUFFER_INSERTION; + } + + /* Searching for the packet that fits best */ + + /* Search the buffer for a packet with the right timestamp and spanning the whole current chunk */ + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && jitter->packets[i].timestamp==jitter->pointer_timestamp && GE32(jitter->packets[i].timestamp+jitter->packets[i].span,jitter->pointer_timestamp+desired_span)) + break; + } + + /* If no match, try for an "older" packet that still spans (fully) the current chunk */ + if (i==SPEEX_JITTER_MAX_BUFFER_SIZE) + { + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && LE32(jitter->packets[i].timestamp, jitter->pointer_timestamp) && GE32(jitter->packets[i].timestamp+jitter->packets[i].span,jitter->pointer_timestamp+desired_span)) + break; + } + } + + /* If still no match, try for an "older" packet that spans part of the current chunk */ + if (i==SPEEX_JITTER_MAX_BUFFER_SIZE) + { + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && LE32(jitter->packets[i].timestamp, jitter->pointer_timestamp) && GT32(jitter->packets[i].timestamp+jitter->packets[i].span,jitter->pointer_timestamp)) + break; + } + } + + /* If still no match, try for earliest packet possible */ + if (i==SPEEX_JITTER_MAX_BUFFER_SIZE) + { + int found = 0; + spx_uint32_t best_time=0; + int best_span=0; + int besti=0; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + /* check if packet starts within current chunk */ + if (jitter->packets[i].data && LT32(jitter->packets[i].timestamp,jitter->pointer_timestamp+desired_span) && GE32(jitter->packets[i].timestamp,jitter->pointer_timestamp)) + { + if (!found || LT32(jitter->packets[i].timestamp,best_time) || (jitter->packets[i].timestamp==best_time && GT32(jitter->packets[i].span,best_span))) + { + best_time = jitter->packets[i].timestamp; + best_span = jitter->packets[i].span; + besti = i; + found = 1; + } + } + } + if (found) + { + i=besti; + incomplete = 1; + /*fprintf (stderr, "incomplete: %d %d %d %d\n", jitter->packets[i].timestamp, jitter->pointer_timestamp, chunk_size, jitter->packets[i].span);*/ + } + } + + /* If we find something */ + if (i!=SPEEX_JITTER_MAX_BUFFER_SIZE) + { + spx_int32_t offset; + + /* We (obviously) haven't lost this packet */ + jitter->lost_count = 0; + + /* In this case, 0 isn't as a valid timestamp */ + if (jitter->arrival[i] != 0) + { + update_timings(jitter, ((spx_int32_t)jitter->packets[i].timestamp) - ((spx_int32_t)jitter->arrival[i]) - jitter->buffer_margin); + } + + + /* Copy packet */ + if (jitter->destroy) + { + packet->data = jitter->packets[i].data; + packet->len = jitter->packets[i].len; + } else { + if (jitter->packets[i].len > packet->len) + { + speex_warning_int("jitter_buffer_get(): packet too large to fit. Size is", jitter->packets[i].len); + } else { + packet->len = jitter->packets[i].len; + } + for (j=0;j<packet->len;j++) + packet->data[j] = jitter->packets[i].data[j]; + /* Remove packet */ + speex_free(jitter->packets[i].data); + } + jitter->packets[i].data = NULL; + /* Set timestamp and span (if requested) */ + offset = (spx_int32_t)jitter->packets[i].timestamp-(spx_int32_t)jitter->pointer_timestamp; + if (start_offset != NULL) + *start_offset = offset; + else if (offset != 0) + speex_warning_int("jitter_buffer_get() discarding non-zero start_offset", offset); + + packet->timestamp = jitter->packets[i].timestamp; + jitter->last_returned_timestamp = packet->timestamp; + + packet->span = jitter->packets[i].span; + packet->sequence = jitter->packets[i].sequence; + packet->user_data = jitter->packets[i].user_data; + /* Point to the end of the current packet */ + jitter->pointer_timestamp = jitter->packets[i].timestamp+jitter->packets[i].span; + + jitter->buffered = packet->span - desired_span; + + if (start_offset != NULL) + jitter->buffered += *start_offset; + + return JITTER_BUFFER_OK; + } + + + /* If we haven't found anything worth returning */ + + /*fprintf (stderr, "not found\n");*/ + jitter->lost_count++; + /*fprintf (stderr, "m");*/ + /*fprintf (stderr, "lost_count = %d\n", jitter->lost_count);*/ + + opt = compute_opt_delay(jitter); + + /* Should we force an increase in the buffer or just do normal interpolation? */ + if (opt < 0) + { + /* Need to increase buffering */ + + /* Shift histogram to compensate */ + shift_timings(jitter, -opt); + + packet->timestamp = jitter->pointer_timestamp; + packet->span = -opt; + /* Don't move the pointer_timestamp forward */ + packet->len = 0; + + jitter->buffered = packet->span - desired_span; + return JITTER_BUFFER_INSERTION; + /*jitter->pointer_timestamp -= jitter->delay_step;*/ + /*fprintf (stderr, "Forced to interpolate\n");*/ + } else { + /* Normal packet loss */ + packet->timestamp = jitter->pointer_timestamp; + + desired_span = ROUND_DOWN(desired_span, jitter->concealment_size); + packet->span = desired_span; + jitter->pointer_timestamp += desired_span; + packet->len = 0; + + jitter->buffered = packet->span - desired_span; + return JITTER_BUFFER_MISSING; + /*fprintf (stderr, "Normal loss\n");*/ + } + + +} + +int jitter_buffer_get_another(JitterBuffer *jitter, JitterBufferPacket *packet) +{ + int i, j; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && jitter->packets[i].timestamp==jitter->last_returned_timestamp) + break; + } + if (i!=SPEEX_JITTER_MAX_BUFFER_SIZE) + { + /* Copy packet */ + packet->len = jitter->packets[i].len; + if (jitter->destroy) + { + packet->data = jitter->packets[i].data; + } else { + for (j=0;j<packet->len;j++) + packet->data[j] = jitter->packets[i].data[j]; + /* Remove packet */ + speex_free(jitter->packets[i].data); + } + jitter->packets[i].data = NULL; + packet->timestamp = jitter->packets[i].timestamp; + packet->span = jitter->packets[i].span; + packet->sequence = jitter->packets[i].sequence; + packet->user_data = jitter->packets[i].user_data; + return JITTER_BUFFER_OK; + } else { + packet->data = NULL; + packet->len = 0; + packet->span = 0; + return JITTER_BUFFER_MISSING; + } +} + +/* Let the jitter buffer know it's the right time to adjust the buffering delay to the network conditions */ +static int _jitter_buffer_update_delay(JitterBuffer *jitter, JitterBufferPacket *packet, spx_int32_t *start_offset) +{ + spx_int16_t opt = compute_opt_delay(jitter); + /*fprintf(stderr, "opt adjustment is %d ", opt);*/ + + if (opt < 0) + { + shift_timings(jitter, -opt); + + jitter->pointer_timestamp += opt; + jitter->interp_requested = -opt; + /*fprintf (stderr, "Decision to interpolate %d samples\n", -opt);*/ + } else if (opt > 0) + { + shift_timings(jitter, -opt); + jitter->pointer_timestamp += opt; + /*fprintf (stderr, "Decision to drop %d samples\n", opt);*/ + } + + return opt; +} + +/* Let the jitter buffer know it's the right time to adjust the buffering delay to the network conditions */ +int jitter_buffer_update_delay(JitterBuffer *jitter, JitterBufferPacket *packet, spx_int32_t *start_offset) +{ + /* If the programmer calls jitter_buffer_update_delay() directly, + automatically disable auto-adjustment */ + jitter->auto_adjust = 0; + + return _jitter_buffer_update_delay(jitter, packet, start_offset); +} + +/** Get pointer timestamp of jitter buffer */ +int jitter_buffer_get_pointer_timestamp(JitterBuffer *jitter) +{ + return jitter->pointer_timestamp; +} + +void jitter_buffer_tick(JitterBuffer *jitter) +{ + /* Automatically-adjust the buffering delay if requested */ + if (jitter->auto_adjust) + _jitter_buffer_update_delay(jitter, NULL, NULL); + + if (jitter->buffered >= 0) + { + jitter->next_stop = jitter->pointer_timestamp - jitter->buffered; + } else { + jitter->next_stop = jitter->pointer_timestamp; + speex_warning_int("jitter buffer sees negative buffering, your code might be broken. Value is ", jitter->buffered); + } + jitter->buffered = 0; +} + +void jitter_buffer_remaining_span(JitterBuffer *jitter, spx_uint32_t rem) +{ + /* Automatically-adjust the buffering delay if requested */ + if (jitter->auto_adjust) + _jitter_buffer_update_delay(jitter, NULL, NULL); + + if (jitter->buffered < 0) + speex_warning_int("jitter buffer sees negative buffering, your code might be broken. Value is ", jitter->buffered); + jitter->next_stop = jitter->pointer_timestamp - rem; +} + + +/* Used like the ioctl function to control the jitter buffer parameters */ +int jitter_buffer_ctl(JitterBuffer *jitter, int request, void *ptr) +{ + int count, i; + switch(request) + { + case JITTER_BUFFER_SET_MARGIN: + jitter->buffer_margin = *(spx_int32_t*)ptr; + break; + case JITTER_BUFFER_GET_MARGIN: + *(spx_int32_t*)ptr = jitter->buffer_margin; + break; + case JITTER_BUFFER_GET_AVALIABLE_COUNT: + count = 0; + for (i=0;i<SPEEX_JITTER_MAX_BUFFER_SIZE;i++) + { + if (jitter->packets[i].data && LE32(jitter->pointer_timestamp, jitter->packets[i].timestamp)) + { + count++; + } + } + *(spx_int32_t*)ptr = count; + break; + case JITTER_BUFFER_SET_DESTROY_CALLBACK: + jitter->destroy = (void (*) (void *))ptr; + break; + case JITTER_BUFFER_GET_DESTROY_CALLBACK: + *(void (**) (void *))ptr = jitter->destroy; + break; + case JITTER_BUFFER_SET_DELAY_STEP: + jitter->delay_step = *(spx_int32_t*)ptr; + break; + case JITTER_BUFFER_GET_DELAY_STEP: + *(spx_int32_t*)ptr = jitter->delay_step; + break; + case JITTER_BUFFER_SET_CONCEALMENT_SIZE: + jitter->concealment_size = *(spx_int32_t*)ptr; + break; + case JITTER_BUFFER_GET_CONCEALMENT_SIZE: + *(spx_int32_t*)ptr = jitter->concealment_size; + break; + case JITTER_BUFFER_SET_MAX_LATE_RATE: + jitter->max_late_rate = *(spx_int32_t*)ptr; + jitter->window_size = 100*TOP_DELAY/jitter->max_late_rate; + jitter->subwindow_size = jitter->window_size/MAX_BUFFERS; + break; + case JITTER_BUFFER_GET_MAX_LATE_RATE: + *(spx_int32_t*)ptr = jitter->max_late_rate; + break; + case JITTER_BUFFER_SET_LATE_COST: + jitter->latency_tradeoff = *(spx_int32_t*)ptr; + break; + case JITTER_BUFFER_GET_LATE_COST: + *(spx_int32_t*)ptr = jitter->latency_tradeoff; + break; + default: + speex_warning_int("Unknown jitter_buffer_ctl request: ", request); + return -1; + } + return 0; +} + |