tomato/toxav/audio.c
Green Sky fe6c5391a2 Squashed 'external/toxcore/c-toxcore/' changes from 671b1f92332..03e9fbf3703
03e9fbf3703 fix: Use Opus in the CBR mode

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 03e9fbf3703e430d21138c4f69e9ac7dbefb7564
2024-09-22 12:48:22 +02:00

512 lines
16 KiB
C

/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2016-2018 The TokTok team.
* Copyright © 2013-2015 Tox project.
*/
#include "audio.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "rtp.h"
#include "../toxcore/ccompat.h"
#include "../toxcore/logger.h"
#include "../toxcore/mono_time.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(const Logger *log, struct JitterBuffer *q, struct RTPMessage *m);
static struct RTPMessage *jbuf_read(struct JitterBuffer *q, int32_t *success);
static OpusEncoder *create_audio_encoder(const Logger *log, uint32_t bit_rate, uint32_t sampling_rate,
uint8_t channel_count);
static bool reconfigure_audio_encoder(const Logger *log, OpusEncoder **e, uint32_t new_br, uint32_t new_sr,
uint8_t new_ch, uint32_t *old_br, uint32_t *old_sr, uint8_t *old_ch);
static bool reconfigure_audio_decoder(ACSession *ac, uint32_t sampling_rate, uint8_t channels);
ACSession *ac_new(Mono_Time *mono_time, const Logger *log, ToxAV *av, uint32_t friend_number,
toxav_audio_receive_frame_cb *cb, void *cb_data)
{
ACSession *ac = (ACSession *)calloc(1, sizeof(ACSession));
if (ac == nullptr) {
LOGGER_WARNING(log, "Allocation failed! Application might misbehave!");
return nullptr;
}
if (create_recursive_mutex(ac->queue_mutex) != 0) {
LOGGER_WARNING(log, "Failed to create recursive mutex!");
free(ac);
return nullptr;
}
int status;
ac->decoder = opus_decoder_create(AUDIO_DECODER_START_SAMPLE_RATE, AUDIO_DECODER_START_CHANNEL_COUNT, &status);
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while starting audio decoder: %s", opus_strerror(status));
goto BASE_CLEANUP;
}
ac->j_buf = jbuf_new(AUDIO_JITTERBUFFER_COUNT);
if (ac->j_buf == nullptr) {
LOGGER_WARNING(log, "Jitter buffer creaton failed!");
opus_decoder_destroy(ac->decoder);
goto BASE_CLEANUP;
}
ac->mono_time = mono_time;
ac->log = log;
/* Initialize encoders with default values */
ac->encoder = create_audio_encoder(log, AUDIO_START_BITRATE, AUDIO_START_SAMPLE_RATE, AUDIO_START_CHANNEL_COUNT);
if (ac->encoder == nullptr) {
goto DECODER_CLEANUP;
}
ac->le_bit_rate = AUDIO_START_BITRATE;
ac->le_sample_rate = AUDIO_START_SAMPLE_RATE;
ac->le_channel_count = AUDIO_START_CHANNEL_COUNT;
ac->ld_channel_count = AUDIO_DECODER_START_CHANNEL_COUNT;
ac->ld_sample_rate = AUDIO_DECODER_START_SAMPLE_RATE;
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 = AUDIO_MAX_FRAME_DURATION_MS;
ac->lp_sampling_rate = AUDIO_DECODER_START_SAMPLE_RATE;
ac->lp_channel_count = AUDIO_DECODER_START_CHANNEL_COUNT;
ac->av = av;
ac->friend_number = friend_number;
ac->acb = cb;
ac->acb_user_data = cb_data;
return ac;
DECODER_CLEANUP:
opus_decoder_destroy(ac->decoder);
jbuf_free((struct JitterBuffer *)ac->j_buf);
BASE_CLEANUP:
pthread_mutex_destroy(ac->queue_mutex);
free(ac);
return nullptr;
}
void ac_kill(ACSession *ac)
{
if (ac == nullptr) {
return;
}
opus_encoder_destroy(ac->encoder);
opus_decoder_destroy(ac->decoder);
jbuf_free((struct JitterBuffer *)ac->j_buf);
pthread_mutex_destroy(ac->queue_mutex);
LOGGER_DEBUG(ac->log, "Terminated audio handler: %p", (void *)ac);
free(ac);
}
void ac_iterate(ACSession *ac)
{
if (ac == nullptr) {
return;
}
/* TODO: fix this and jitter buffering */
/* Enough space for the maximum frame size (120 ms 48 KHz stereo audio) */
int16_t *temp_audio_buffer = (int16_t *)malloc(AUDIO_MAX_BUFFER_SIZE_PCM16 * AUDIO_MAX_CHANNEL_COUNT * sizeof(int16_t));
if (temp_audio_buffer == nullptr) {
LOGGER_ERROR(ac->log, "Failed to allocate memory for audio buffer");
return;
}
pthread_mutex_lock(ac->queue_mutex);
struct JitterBuffer *const j_buf = (struct JitterBuffer *)ac->j_buf;
int rc = 0;
for (struct RTPMessage *msg = jbuf_read(j_buf, &rc); msg != nullptr || rc == 2; msg = jbuf_read(j_buf, &rc)) {
pthread_mutex_unlock(ac->queue_mutex);
if (rc == 2) {
LOGGER_DEBUG(ac->log, "OPUS correction");
const int fs = (ac->lp_sampling_rate * ac->lp_frame_duration) / 1000;
rc = opus_decode(ac->decoder, nullptr, 0, temp_audio_buffer, fs, 1);
} else {
assert(msg->len > 4);
/* Pick up sampling rate from packet */
memcpy(&ac->lp_sampling_rate, msg->data, 4);
ac->lp_sampling_rate = net_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(ac->log, "Failed to reconfigure decoder!");
free(msg);
pthread_mutex_lock(ac->queue_mutex);
continue;
}
/*
* frame_size = opus_decode(dec, packet, len, decoded, max_size, 0);
* where
* packet is the byte array containing the compressed data
* len is the exact number of bytes contained in the packet
* decoded is the decoded audio data in opus_int16 (or float for opus_decode_float())
* max_size is the max duration of the frame in samples (per channel) that can fit
* into the decoded_frame array
*/
rc = opus_decode(ac->decoder, msg->data + 4, msg->len - 4, temp_audio_buffer, 5760, 0);
free(msg);
}
if (rc < 0) {
LOGGER_WARNING(ac->log, "Decoding error: %s", opus_strerror(rc));
} else if (ac->acb != nullptr) {
ac->lp_frame_duration = (rc * 1000) / ac->lp_sampling_rate;
ac->acb(ac->av, ac->friend_number, temp_audio_buffer, rc, ac->lp_channel_count,
ac->lp_sampling_rate, ac->acb_user_data);
}
free(temp_audio_buffer);
return;
}
pthread_mutex_unlock(ac->queue_mutex);
free(temp_audio_buffer);
}
int ac_queue_message(Mono_Time *mono_time, void *cs, struct RTPMessage *msg)
{
ACSession *ac = (ACSession *)cs;
if (ac == nullptr || msg == nullptr) {
free(msg);
return -1;
}
if ((msg->header.pt & 0x7f) == (RTP_TYPE_AUDIO + 2) % 128) {
LOGGER_WARNING(ac->log, "Got dummy!");
free(msg);
return 0;
}
if ((msg->header.pt & 0x7f) != RTP_TYPE_AUDIO % 128) {
LOGGER_WARNING(ac->log, "Invalid payload type!");
free(msg);
return -1;
}
pthread_mutex_lock(ac->queue_mutex);
const int rc = jbuf_write(ac->log, (struct JitterBuffer *)ac->j_buf, msg);
pthread_mutex_unlock(ac->queue_mutex);
if (rc == -1) {
LOGGER_WARNING(ac->log, "Could not queue the message!");
free(msg);
return -1;
}
return 0;
}
int ac_reconfigure_encoder(ACSession *ac, uint32_t bit_rate, uint32_t sampling_rate, uint8_t channels)
{
if (ac == nullptr || !reconfigure_audio_encoder(
ac->log, &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 = (struct JitterBuffer *)calloc(1, sizeof(struct JitterBuffer));
if (q == nullptr) {
return nullptr;
}
q->queue = (struct RTPMessage **)calloc(size, sizeof(struct RTPMessage *));
if (q->queue == nullptr) {
free(q);
return nullptr;
}
q->size = size;
q->capacity = capacity;
return q;
}
static void jbuf_clear(struct JitterBuffer *q)
{
while (q->bottom != q->top) {
free(q->queue[q->bottom % q->size]);
q->queue[q->bottom % q->size] = nullptr;
++q->bottom;
}
}
static void jbuf_free(struct JitterBuffer *q)
{
if (q == nullptr) {
return;
}
jbuf_clear(q);
free(q->queue);
free(q);
}
static int jbuf_write(const Logger *log, struct JitterBuffer *q, struct RTPMessage *m)
{
const uint16_t sequnum = m->header.sequnum;
const unsigned int num = sequnum % q->size;
if ((uint32_t)(sequnum - q->bottom) > q->size) {
LOGGER_DEBUG(log, "Clearing filled jitter buffer: %p", (void *)q);
jbuf_clear(q);
q->bottom = sequnum - q->capacity;
q->queue[num] = m;
q->top = sequnum + 1;
return 0;
}
if (q->queue[num] != nullptr) {
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 nullptr;
}
const unsigned int num = q->bottom % q->size;
if (q->queue[num] != nullptr) {
struct RTPMessage *ret = q->queue[num];
q->queue[num] = nullptr;
++q->bottom;
*success = 1;
return ret;
}
if ((uint32_t)(q->top - q->bottom) > q->capacity) {
++q->bottom;
*success = 2;
return nullptr;
}
*success = 0;
return nullptr;
}
static OpusEncoder *create_audio_encoder(const Logger *log, uint32_t bit_rate, uint32_t sampling_rate,
uint8_t channel_count)
{
int status = OPUS_OK;
/*
* OPUS_APPLICATION_VOIP Process signal for improved speech intelligibility
* OPUS_APPLICATION_AUDIO Favor faithfulness to the original input
* OPUS_APPLICATION_RESTRICTED_LOWDELAY Configure the minimum possible coding delay
*/
OpusEncoder *rc = opus_encoder_create(sampling_rate, channel_count, OPUS_APPLICATION_VOIP, &status);
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while starting audio encoder: %s", opus_strerror(status));
return nullptr;
}
/*
* Rates from 500 to 512000 bits per second are meaningful as well as the special
* values OPUS_BITRATE_AUTO and OPUS_BITRATE_MAX. The value OPUS_BITRATE_MAX can
* be used to cause the codec to use as much rate as it can, which is useful for
* controlling the rate by adjusting the output buffer size.
*
* Parameters:
* `[in]` `x` `opus_int32`: bitrate in bits per second.
*/
status = opus_encoder_ctl(rc, OPUS_SET_BITRATE(bit_rate));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while setting encoder ctl: %s", opus_strerror(status));
goto FAILURE;
}
/*
* The libopus library defaults to VBR, which is unsafe in any VoIP environment
* (see for example doi:10.1109/SP.2011.34). Switching to CBR very slightly
* decreases audio quality at lower bitrates.
*
* Parameters:
* `[in]` `x` `opus_int32`: Whether to use VBR mode, 1 (VBR) is default
*/
status = opus_encoder_ctl(rc, OPUS_SET_VBR(0));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while setting encoder ctl: %s", opus_strerror(status));
goto FAILURE;
}
/*
* Configures the encoder's use of inband forward error correction.
* Note:
* This is only applicable to the LPC layer
* Parameters:
* `[in]` `x` `int`: FEC flag, 0 (disabled) is default
*/
/* Enable in-band forward error correction in codec */
status = opus_encoder_ctl(rc, OPUS_SET_INBAND_FEC(1));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while setting encoder ctl: %s", opus_strerror(status));
goto FAILURE;
}
/*
* Configures the encoder's expected packet loss percentage.
* Higher values with trigger progressively more loss resistant behavior in
* the encoder at the expense of quality at a given bitrate in the lossless case,
* but greater quality under loss.
* Parameters:
* `[in]` `x` `int`: Loss percentage in the range 0-100, inclusive.
*/
/* 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(AUDIO_OPUS_PACKET_LOSS_PERC));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while setting encoder ctl: %s", opus_strerror(status));
goto FAILURE;
}
/*
* Configures the encoder's computational complexity.
*
* The supported range is 0-10 inclusive with 10 representing the highest complexity.
* The default value is 10.
*
* Parameters:
* `[in]` `x` `int`: 0-10, inclusive
*/
/* Set algorithm to the highest complexity, maximizing compression */
status = opus_encoder_ctl(rc, OPUS_SET_COMPLEXITY(AUDIO_OPUS_COMPLEXITY));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "Error while setting encoder ctl: %s", opus_strerror(status));
goto FAILURE;
}
return rc;
FAILURE:
opus_encoder_destroy(rc);
return nullptr;
}
static bool reconfigure_audio_encoder(const Logger *log, OpusEncoder **e, uint32_t new_br, uint32_t new_sr,
uint8_t new_ch, uint32_t *old_br, uint32_t *old_sr, uint8_t *old_ch)
{
/* Values are checked in toxav.c */
if (*old_sr != new_sr || *old_ch != new_ch) {
OpusEncoder *new_encoder = create_audio_encoder(log, new_br, new_sr, new_ch);
if (new_encoder == nullptr) {
return false;
}
opus_encoder_destroy(*e);
*e = new_encoder;
} else if (*old_br == new_br) {
return true; /* Nothing changed */
}
const int status = opus_encoder_ctl(*e, OPUS_SET_BITRATE(new_br));
if (status != OPUS_OK) {
LOGGER_ERROR(log, "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(log, "Reconfigured audio encoder br: %d sr: %d cc:%d", new_br, new_sr, new_ch);
return true;
}
static bool reconfigure_audio_decoder(ACSession *ac, uint32_t sampling_rate, uint8_t channels)
{
if (sampling_rate != ac->ld_sample_rate || channels != ac->ld_channel_count) {
if (current_time_monotonic(ac->mono_time) - ac->ldrts < 500) {
return false;
}
int status;
OpusDecoder *new_dec = opus_decoder_create(sampling_rate, channels, &status);
if (status != OPUS_OK) {
LOGGER_ERROR(ac->log, "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(ac->mono_time);
opus_decoder_destroy(ac->decoder);
ac->decoder = new_dec;
LOGGER_DEBUG(ac->log, "Reconfigured audio decoder sr: %d cc: %d", sampling_rate, channels);
}
return true;
}