1 files changed, 439 insertions, 0 deletions

diff --git a/toxav/audio.c b/toxav/audio.c
new file mode 100644
index 00000000..ad543502
--- /dev/null
+++ b/toxav/audio.c
@@ -0,0 +1,439 @@
+/**  audio.c
+ *
+ *   Copyright (C) 2013-2015 Tox project All Rights Reserved.
+ *
+ *   This file is part of Tox.
+ *
+ *   Tox is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   Tox 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 Tox. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include <stdlib.h>
+
+#include "audio.h"
+#include "rtp.h"
+
+#include "../toxcore/logger.h"
+
+static struct JitterBuffer *jbuf_new(uint32_t capacity);
+static void jbuf_clear(struct JitterBuffer *q);
+static void jbuf_free(struct JitterBuffer *q);
+static int jbuf_write(struct JitterBuffer *q, struct RTPMessage *m);
+static struct RTPMessage *jbuf_read(struct JitterBuffer *q, int32_t *success);
+OpusEncoder *create_audio_encoder (int32_t bit_rate, int32_t sampling_rate, int32_t channel_count);
+bool reconfigure_audio_encoder(OpusEncoder **e, int32_t new_br, int32_t new_sr, uint8_t new_ch,
+                               int32_t *old_br, int32_t *old_sr, int32_t *old_ch);
+bool reconfigure_audio_decoder(ACSession *ac, int32_t sampling_rate, int8_t channels);
+
+
+
+ACSession *ac_new(ToxAV *av, uint32_t friend_number, toxav_audio_receive_frame_cb *cb, void *cb_data)
+{
+    ACSession *ac = calloc(sizeof(ACSession), 1);
+
+    if (!ac) {
+        LOGGER_WARNING("Allocation failed! Application might misbehave!");
+        return NULL;
+    }
+
+    if (create_recursive_mutex(ac->queue_mutex) != 0) {
+        LOGGER_WARNING("Failed to create recursive mutex!");
+        free(ac);
+        return NULL;
+    }
+
+    int status;
+    ac->decoder = opus_decoder_create(48000, 2, &status);
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while starting audio decoder: %s", opus_strerror(status));
+        goto BASE_CLEANUP;
+    }
+
+    if (!(ac->j_buf = jbuf_new(3))) {
+        LOGGER_WARNING("Jitter buffer creaton failed!");
+        opus_decoder_destroy(ac->decoder);
+        goto BASE_CLEANUP;
+    }
+
+    /* Initialize encoders with default values */
+    ac->encoder = create_audio_encoder(48000, 48000, 2);
+
+    if (ac->encoder == NULL)
+        goto DECODER_CLEANUP;
+
+    ac->le_bit_rate = 48000;
+    ac->le_sample_rate = 48000;
+    ac->le_channel_count = 2;
+
+    ac->ld_channel_count = 2;
+    ac->ld_sample_rate = 48000;
+    ac->ldrts = 0; /* Make it possible to reconfigure straight away */
+
+    /* These need to be set in order to properly
+     * do error correction with opus */
+    ac->lp_frame_duration = 120;
+    ac->lp_sampling_rate = 48000;
+    ac->lp_channel_count = 1;
+
+    ac->av = av;
+    ac->friend_number = friend_number;
+    ac->acb.first = cb;
+    ac->acb.second = cb_data;
+
+    return ac;
+
+DECODER_CLEANUP:
+    opus_decoder_destroy(ac->decoder);
+    jbuf_free(ac->j_buf);
+BASE_CLEANUP:
+    pthread_mutex_destroy(ac->queue_mutex);
+    free(ac);
+    return NULL;
+}
+void ac_kill(ACSession *ac)
+{
+    if (!ac)
+        return;
+
+    opus_encoder_destroy(ac->encoder);
+    opus_decoder_destroy(ac->decoder);
+    jbuf_free(ac->j_buf);
+
+    pthread_mutex_destroy(ac->queue_mutex);
+
+    LOGGER_DEBUG("Terminated audio handler: %p", ac);
+    free(ac);
+}
+void ac_iterate(ACSession *ac)
+{
+    if (!ac)
+        return;
+
+    /* TODO fix this and jitter buffering */
+
+    /* Enough space for the maximum frame size (120 ms 48 KHz stereo audio) */
+    int16_t tmp[5760 * 2];
+
+    struct RTPMessage *msg;
+    int rc = 0;
+
+    pthread_mutex_lock(ac->queue_mutex);
+
+    while ((msg = jbuf_read(ac->j_buf, &rc)) || rc == 2) {
+        pthread_mutex_unlock(ac->queue_mutex);
+
+        if (rc == 2) {
+            LOGGER_DEBUG("OPUS correction");
+            int fs = (ac->lp_sampling_rate * ac->lp_frame_duration) / 1000;
+            rc = opus_decode(ac->decoder, NULL, 0, tmp, fs, 1);
+        } else {
+            /* Get values from packet and decode. */
+            /* NOTE: This didn't work very well
+            rc = convert_bw_to_sampling_rate(opus_packet_get_bandwidth(msg->data));
+            if (rc != -1) {
+                cs->last_packet_sampling_rate = rc;
+            } else {
+                LOGGER_WARNING("Failed to load packet values!");
+                rtp_free_msg(msg);
+                continue;
+            }*/
+
+
+            /* Pick up sampling rate from packet */
+            memcpy(&ac->lp_sampling_rate, msg->data, 4);
+            ac->lp_sampling_rate = ntohl(ac->lp_sampling_rate);
+
+            ac->lp_channel_count = opus_packet_get_nb_channels(msg->data + 4);
+
+            /** NOTE: even though OPUS supports decoding mono frames with stereo decoder and vice versa,
+              * it didn't work quite well.
+              */
+            if (!reconfigure_audio_decoder(ac, ac->lp_sampling_rate, ac->lp_channel_count)) {
+                LOGGER_WARNING("Failed to reconfigure decoder!");
+                free(msg);
+                continue;
+            }
+
+            rc = opus_decode(ac->decoder, msg->data + 4, msg->len - 4, tmp, 5760, 0);
+            free(msg);
+        }
+
+        if (rc < 0) {
+            LOGGER_WARNING("Decoding error: %s", opus_strerror(rc));
+        } else if (ac->acb.first) {
+            ac->lp_frame_duration = (rc * 1000) / ac->lp_sampling_rate;
+
+            ac->acb.first(ac->av, ac->friend_number, tmp, rc, ac->lp_channel_count,
+                          ac->lp_sampling_rate, ac->acb.second);
+        }
+
+        return;
+    }
+
+    pthread_mutex_unlock(ac->queue_mutex);
+}
+int ac_queue_message(void *acp, struct RTPMessage *msg)
+{
+    if (!acp || !msg)
+        return -1;
+
+    if ((msg->header.pt & 0x7f) == (rtp_TypeAudio + 2) % 128) {
+        LOGGER_WARNING("Got dummy!");
+        free(msg);
+        return 0;
+    }
+
+    if ((msg->header.pt & 0x7f) != rtp_TypeAudio % 128) {
+        LOGGER_WARNING("Invalid payload type!");
+        free(msg);
+        return -1;
+    }
+
+    ACSession *ac = acp;
+
+    pthread_mutex_lock(ac->queue_mutex);
+    int rc = jbuf_write(ac->j_buf, msg);
+    pthread_mutex_unlock(ac->queue_mutex);
+
+    if (rc == -1) {
+        LOGGER_WARNING("Could not queue the message!");
+        free(msg);
+        return -1;
+    }
+
+    return 0;
+}
+int ac_reconfigure_encoder(ACSession *ac, int32_t bit_rate, int32_t sampling_rate, uint8_t channels)
+{
+    if (!ac || !reconfigure_audio_encoder(&ac->encoder, bit_rate,
+                                          sampling_rate, channels,
+                                          &ac->le_bit_rate,
+                                          &ac->le_sample_rate,
+                                          &ac->le_channel_count))
+        return -1;
+
+    return 0;
+}
+
+
+
+struct JitterBuffer {
+    struct RTPMessage **queue;
+    uint32_t size;
+    uint32_t capacity;
+    uint16_t bottom;
+    uint16_t top;
+};
+
+static struct JitterBuffer *jbuf_new(uint32_t capacity)
+{
+    unsigned int size = 1;
+
+    while (size <= (capacity * 4)) {
+        size *= 2;
+    }
+
+    struct JitterBuffer *q;
+
+    if (!(q = calloc(sizeof(struct JitterBuffer), 1))) return NULL;
+
+    if (!(q->queue = calloc(sizeof(struct RTPMessage *), size))) {
+        free(q);
+        return NULL;
+    }
+
+    q->size = size;
+    q->capacity = capacity;
+    return q;
+}
+static void jbuf_clear(struct JitterBuffer *q)
+{
+    for (; q->bottom != q->top; ++q->bottom) {
+        if (q->queue[q->bottom % q->size]) {
+            free(q->queue[q->bottom % q->size]);
+            q->queue[q->bottom % q->size] = NULL;
+        }
+    }
+}
+static void jbuf_free(struct JitterBuffer *q)
+{
+    if (!q) return;
+
+    jbuf_clear(q);
+    free(q->queue);
+    free(q);
+}
+static int jbuf_write(struct JitterBuffer *q, struct RTPMessage *m)
+{
+    uint16_t sequnum = m->header.sequnum;
+
+    unsigned int num = sequnum % q->size;
+
+    if ((uint32_t)(sequnum - q->bottom) > q->size) {
+        LOGGER_DEBUG("Clearing filled jitter buffer: %p", q);
+
+        jbuf_clear(q);
+        q->bottom = sequnum - q->capacity;
+        q->queue[num] = m;
+        q->top = sequnum + 1;
+        return 0;
+    }
+
+    if (q->queue[num])
+        return -1;
+
+    q->queue[num] = m;
+
+    if ((sequnum - q->bottom) >= (q->top - q->bottom))
+        q->top = sequnum + 1;
+
+    return 0;
+}
+static struct RTPMessage *jbuf_read(struct JitterBuffer *q, int32_t *success)
+{
+    if (q->top == q->bottom) {
+        *success = 0;
+        return NULL;
+    }
+
+    unsigned int num = q->bottom % q->size;
+
+    if (q->queue[num]) {
+        struct RTPMessage *ret = q->queue[num];
+        q->queue[num] = NULL;
+        ++q->bottom;
+        *success = 1;
+        return ret;
+    }
+
+    if ((uint32_t)(q->top - q->bottom) > q->capacity) {
+        ++q->bottom;
+        *success = 2;
+        return NULL;
+    }
+
+    *success = 0;
+    return NULL;
+}
+OpusEncoder *create_audio_encoder (int32_t bit_rate, int32_t sampling_rate, int32_t channel_count)
+{
+    int status = OPUS_OK;
+    OpusEncoder *rc = opus_encoder_create(sampling_rate, channel_count, OPUS_APPLICATION_VOIP, &status);
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while starting audio encoder: %s", opus_strerror(status));
+        return NULL;
+    }
+
+    status = opus_encoder_ctl(rc, OPUS_SET_BITRATE(bit_rate));
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while setting encoder ctl: %s", opus_strerror(status));
+        goto FAILURE;
+    }
+
+    /* Enable in-band forward error correction in codec */
+    status = opus_encoder_ctl(rc, OPUS_SET_INBAND_FEC(1));
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while setting encoder ctl: %s", opus_strerror(status));
+        goto FAILURE;
+    }
+
+    /* Make codec resistant to up to 10% packet loss
+     * NOTE This could also be adjusted on the fly, rather than hard-coded,
+     *      with feedback from the receiving client.
+     */
+    status = opus_encoder_ctl(rc, OPUS_SET_PACKET_LOSS_PERC(10));
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while setting encoder ctl: %s", opus_strerror(status));
+        goto FAILURE;
+    }
+
+    /* Set algorithm to the highest complexity, maximizing compression */
+    status = opus_encoder_ctl(rc, OPUS_SET_COMPLEXITY(10));
+
+    if (status != OPUS_OK) {
+        LOGGER_ERROR("Error while setting encoder ctl: %s", opus_strerror(status));
+        goto FAILURE;
+    }
+
+    return rc;
+
+FAILURE:
+    opus_encoder_destroy(rc);
+    return NULL;
+}
+bool reconfigure_audio_encoder(OpusEncoder **e, int32_t new_br, int32_t new_sr, uint8_t new_ch,
+                               int32_t *old_br, int32_t *old_sr, int32_t *old_ch)
+{
+    /* Values are checked in toxav.c */
+    if (*old_sr != new_sr || *old_ch != new_ch) {
+        OpusEncoder *new_encoder = create_audio_encoder(new_br, new_sr, new_ch);
+
+        if (new_encoder == NULL)
+            return false;
+
+        opus_encoder_destroy(*e);
+        *e = new_encoder;
+    } else if (*old_br == new_br)
+        return true; /* Nothing changed */
+    else {
+        int status = opus_encoder_ctl(*e, OPUS_SET_BITRATE(new_br));
+
+        if (status != OPUS_OK) {
+            LOGGER_ERROR("Error while setting encoder ctl: %s", opus_strerror(status));
+            return false;
+        }
+    }
+
+    *old_br = new_br;
+    *old_sr = new_sr;
+    *old_ch = new_ch;
+
+    LOGGER_DEBUG ("Reconfigured audio encoder br: %d sr: %d cc:%d", new_br, new_sr, new_ch);
+    return true;
+}
+bool reconfigure_audio_decoder(ACSession *ac, int32_t sampling_rate, int8_t channels)
+{
+    if (sampling_rate != ac->ld_sample_rate || channels != ac->ld_channel_count) {
+        if (current_time_monotonic() - ac->ldrts < 500)
+            return false;
+
+        int status;
+        OpusDecoder *new_dec = opus_decoder_create(sampling_rate, channels, &status);
+
+        if (status != OPUS_OK) {
+            LOGGER_ERROR("Error while starting audio decoder(%d %d): %s", sampling_rate, channels, opus_strerror(status));
+            return false;
+        }
+
+        ac->ld_sample_rate = sampling_rate;
+        ac->ld_channel_count = channels;
+        ac->ldrts = current_time_monotonic();
+
+        opus_decoder_destroy(ac->decoder);
+        ac->decoder = new_dec;
+
+        LOGGER_DEBUG("Reconfigured audio decoder sr: %d cc: %d", sampling_rate, channels);
+    }
+
+    return true;
+}