Use nullptr as NULL pointer constant instead of NULL or 0.

This changes only code, no string literals or comments.

9 files changed, 128 insertions, 125 deletions

diff --git a/toxav/BUILD.bazel b/toxav/BUILD.bazel
index 38bdaeba..e9649c36 100644
--- a/toxav/BUILD.bazel
+++ b/toxav/BUILD.bazel
@@ -15,6 +15,7 @@ cc_library(
     name = "ring_buffer",
     srcs = ["ring_buffer.c"],
     hdrs = ["ring_buffer.h"],
+    deps = ["//c-toxcore/toxcore:ccompat"],
 )
 
 cc_library(
diff --git a/toxav/audio.c b/toxav/audio.c
index f2453e8e..b97560fd 100644
--- a/toxav/audio.c
+++ b/toxav/audio.c
@@ -47,13 +47,13 @@ ACSession *ac_new(Logger *log, ToxAV *av, uint32_t friend_number, toxav_audio_re
 
     if (!ac) {
         LOGGER_WARNING(log, "Allocation failed! Application might misbehave!");
-        return NULL;
+        return nullptr;
     }
 
     if (create_recursive_mutex(ac->queue_mutex) != 0) {
         LOGGER_WARNING(log, "Failed to create recursive mutex!");
         free(ac);
-        return NULL;
+        return nullptr;
     }
 
     int status;
@@ -75,7 +75,7 @@ ACSession *ac_new(Logger *log, ToxAV *av, uint32_t friend_number, toxav_audio_re
     /* 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 == NULL) {
+    if (ac->encoder == nullptr) {
         goto DECODER_CLEANUP;
     }
 
@@ -106,7 +106,7 @@ DECODER_CLEANUP:
 BASE_CLEANUP:
     pthread_mutex_destroy(ac->queue_mutex);
     free(ac);
-    return NULL;
+    return nullptr;
 }
 
 void ac_kill(ACSession *ac)
@@ -147,7 +147,7 @@ void ac_iterate(ACSession *ac)
         if (rc == 2) {
             LOGGER_DEBUG(ac->log, "OPUS correction");
             int fs = (ac->lp_sampling_rate * ac->lp_frame_duration) / 1000;
-            rc = opus_decode(ac->decoder, NULL, 0, temp_audio_buffer, fs, 1);
+            rc = opus_decode(ac->decoder, nullptr, 0, temp_audio_buffer, fs, 1);
         } else {
             /* Get values from packet and decode. */
             /* NOTE: This didn't work very well */
@@ -275,14 +275,14 @@ static struct JitterBuffer *jbuf_new(uint32_t capacity)
     struct JitterBuffer *q = (struct JitterBuffer *)calloc(sizeof(struct JitterBuffer), 1);
 
     if (!q) {
-        return NULL;
+        return nullptr;
     }
 
     q->queue = (struct RTPMessage **)calloc(sizeof(struct RTPMessage *), size);
 
     if (!q->queue) {
         free(q);
-        return NULL;
+        return nullptr;
     }
 
     q->size = size;
@@ -294,7 +294,7 @@ 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;
+            q->queue[q->bottom % q->size] = nullptr;
         }
     }
 }
@@ -340,14 +340,14 @@ static struct RTPMessage *jbuf_read(struct JitterBuffer *q, int32_t *success)
 {
     if (q->top == q->bottom) {
         *success = 0;
-        return NULL;
+        return nullptr;
     }
 
     unsigned int num = q->bottom % q->size;
 
     if (q->queue[num]) {
         struct RTPMessage *ret = q->queue[num];
-        q->queue[num] = NULL;
+        q->queue[num] = nullptr;
         ++q->bottom;
         *success = 1;
         return ret;
@@ -356,11 +356,11 @@ static struct RTPMessage *jbuf_read(struct JitterBuffer *q, int32_t *success)
     if ((uint32_t)(q->top - q->bottom) > q->capacity) {
         ++q->bottom;
         *success = 2;
-        return NULL;
+        return nullptr;
     }
 
     *success = 0;
-    return NULL;
+    return nullptr;
 }
 OpusEncoder *create_audio_encoder(Logger *log, int32_t bit_rate, int32_t sampling_rate, int32_t channel_count)
 {
@@ -374,7 +374,7 @@ OpusEncoder *create_audio_encoder(Logger *log, int32_t bit_rate, int32_t samplin
 
     if (status != OPUS_OK) {
         LOGGER_ERROR(log, "Error while starting audio encoder: %s", opus_strerror(status));
-        return NULL;
+        return nullptr;
     }
 
 
@@ -452,7 +452,7 @@ OpusEncoder *create_audio_encoder(Logger *log, int32_t bit_rate, int32_t samplin
 
 FAILURE:
     opus_encoder_destroy(rc);
-    return NULL;
+    return nullptr;
 }
 
 bool reconfigure_audio_encoder(Logger *log, OpusEncoder **e, int32_t new_br, int32_t new_sr, uint8_t new_ch,
@@ -462,7 +462,7 @@ bool reconfigure_audio_encoder(Logger *log, OpusEncoder **e, int32_t new_br, int
     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 == NULL) {
+        if (new_encoder == nullptr) {
             return false;
         }
 
diff --git a/toxav/bwcontroller.c b/toxav/bwcontroller.c
index eeeab129..9d1ad9ce 100644
--- a/toxav/bwcontroller.c
+++ b/toxav/bwcontroller.c
@@ -97,7 +97,7 @@ void bwc_kill(BWController *bwc)
         return;
     }
 
-    m_callback_rtp_packet(bwc->m, bwc->friend_number, BWC_PACKET_ID, NULL, NULL);
+    m_callback_rtp_packet(bwc->m, bwc->friend_number, BWC_PACKET_ID, nullptr, nullptr);
 
     rb_kill(bwc->rcvpkt.rb);
     free(bwc);
diff --git a/toxav/groupav.c b/toxav/groupav.c
index 418a42aa..c19c1b3c 100644
--- a/toxav/groupav.c
+++ b/toxav/groupav.c
@@ -55,12 +55,12 @@ static Group_JitterBuffer *create_queue(unsigned int capacity)
     Group_JitterBuffer *q;
 
     if (!(q = (Group_JitterBuffer *)calloc(sizeof(Group_JitterBuffer), 1))) {
-        return NULL;
+        return nullptr;
     }
 
     if (!(q->queue = (Group_Audio_Packet **)calloc(sizeof(Group_Audio_Packet *), size))) {
         free(q);
-        return NULL;
+        return nullptr;
     }
 
     q->size = size;
@@ -73,7 +73,7 @@ static void clear_queue(Group_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;
+            q->queue[q->bottom % q->size] = nullptr;
         }
     }
 }
@@ -132,14 +132,14 @@ static Group_Audio_Packet *dequeue(Group_JitterBuffer *q, int *success)
 {
     if (q->top == q->bottom) {
         *success = 0;
-        return NULL;
+        return nullptr;
     }
 
     unsigned int num = q->bottom % q->size;
 
     if (q->queue[num]) {
         Group_Audio_Packet *ret = q->queue[num];
-        q->queue[num] = NULL;
+        q->queue[num] = nullptr;
         ++q->bottom;
         *success = 1;
         return ret;
@@ -148,11 +148,11 @@ static Group_Audio_Packet *dequeue(Group_JitterBuffer *q, int *success)
     if ((uint32_t)(q->top - q->bottom) > q->capacity) {
         ++q->bottom;
         *success = 2;
-        return NULL;
+        return nullptr;
     }
 
     *success = 0;
-    return NULL;
+    return nullptr;
 }
 
 typedef struct {
@@ -190,7 +190,7 @@ static int recreate_encoder(Group_AV *group_av)
 {
     if (group_av->audio_encoder) {
         opus_encoder_destroy(group_av->audio_encoder);
-        group_av->audio_encoder = NULL;
+        group_av->audio_encoder = nullptr;
     }
 
     int rc = OPUS_OK;
@@ -199,7 +199,7 @@ static int recreate_encoder(Group_AV *group_av)
 
     if (rc != OPUS_OK) {
         LOGGER_ERROR(group_av->log, "Error while starting audio encoder: %s", opus_strerror(rc));
-        group_av->audio_encoder = NULL;
+        group_av->audio_encoder = nullptr;
         return -1;
     }
 
@@ -208,7 +208,7 @@ static int recreate_encoder(Group_AV *group_av)
     if (rc != OPUS_OK) {
         LOGGER_ERROR(group_av->log, "Error while setting encoder ctl: %s", opus_strerror(rc));
         opus_encoder_destroy(group_av->audio_encoder);
-        group_av->audio_encoder = NULL;
+        group_av->audio_encoder = nullptr;
         return -1;
     }
 
@@ -217,7 +217,7 @@ static int recreate_encoder(Group_AV *group_av)
     if (rc != OPUS_OK) {
         LOGGER_ERROR(group_av->log, "Error while setting encoder ctl: %s", opus_strerror(rc));
         opus_encoder_destroy(group_av->audio_encoder);
-        group_av->audio_encoder = NULL;
+        group_av->audio_encoder = nullptr;
         return -1;
     }
 
@@ -229,13 +229,13 @@ static Group_AV *new_group_av(Logger *log, Group_Chats *g_c, void (*audio_callba
                               unsigned int, uint8_t, unsigned int, void *), void *userdata)
 {
     if (!g_c) {
-        return NULL;
+        return nullptr;
     }
 
     Group_AV *group_av = (Group_AV *)calloc(1, sizeof(Group_AV));
 
     if (!group_av) {
-        return NULL;
+        return nullptr;
     }
 
     group_av->log = log;
@@ -296,7 +296,7 @@ static int decode_audio_packet(Group_AV *group_av, Group_Peer_AV *peer_av, int g
         return -1;
     }
 
-    int16_t *out_audio = NULL;
+    int16_t *out_audio = nullptr;
     int out_audio_samples = 0;
 
     unsigned int sample_rate = 48000;
@@ -317,7 +317,7 @@ static int decode_audio_packet(Group_AV *group_av, Group_Peer_AV *peer_av, int g
         if (channels != peer_av->decoder_channels) {
             if (peer_av->audio_decoder) {
                 opus_decoder_destroy(peer_av->audio_decoder);
-                peer_av->audio_decoder = NULL;
+                peer_av->audio_decoder = nullptr;
             }
 
             int rc;
@@ -366,7 +366,7 @@ static int decode_audio_packet(Group_AV *group_av, Group_Peer_AV *peer_av, int g
             return -1;
         }
 
-        out_audio_samples = opus_decode(peer_av->audio_decoder, NULL, 0, out_audio, peer_av->last_packet_samples, 1);
+        out_audio_samples = opus_decode(peer_av->audio_decoder, nullptr, 0, out_audio, peer_av->last_packet_samples, 1);
 
         if (out_audio_samples <= 0) {
             free(out_audio);
@@ -436,7 +436,7 @@ static int groupchat_enable_av(Logger *log, Group_Chats *g_c, int groupnumber, v
 
     Group_AV *group_av = new_group_av(log, g_c, audio_callback, userdata);
 
-    if (group_av == NULL) {
+    if (group_av == nullptr) {
         return -1;
     }
 
diff --git a/toxav/msi.c b/toxav/msi.c
index 882dad04..94b7b537 100644
--- a/toxav/msi.c
+++ b/toxav/msi.c
@@ -104,21 +104,21 @@ void msi_register_callback(MSISession *session, msi_action_cb *callback, MSICall
 }
 MSISession *msi_new(Messenger *m)
 {
-    if (m == NULL) {
-        return NULL;
+    if (m == nullptr) {
+        return nullptr;
     }
 
     MSISession *retu = (MSISession *)calloc(sizeof(MSISession), 1);
 
-    if (retu == NULL) {
+    if (retu == nullptr) {
         LOGGER_ERROR(m->log, "Allocation failed! Program might misbehave!");
-        return NULL;
+        return nullptr;
     }
 
     if (create_recursive_mutex(retu->mutex) != 0) {
         LOGGER_ERROR(m->log, "Failed to init mutex! Program might misbehave");
         free(retu);
-        return NULL;
+        return nullptr;
     }
 
     retu->messenger = m;
@@ -133,12 +133,12 @@ MSISession *msi_new(Messenger *m)
 }
 int msi_kill(MSISession *session, Logger *log)
 {
-    if (session == NULL) {
+    if (session == nullptr) {
         LOGGER_ERROR(log, "Tried to terminate non-existing session");
         return -1;
     }
 
-    m_callback_msi_packet((struct Messenger *) session->messenger, NULL, NULL);
+    m_callback_msi_packet((struct Messenger *) session->messenger, nullptr, nullptr);
 
     if (pthread_mutex_trylock(session->mutex) != 0) {
         LOGGER_ERROR(session->messenger->log, "Failed to acquire lock on msi mutex");
@@ -179,7 +179,7 @@ int msi_invite(MSISession *session, MSICall **call, uint32_t friend_number, uint
         return -1;
     }
 
-    if (get_call(session, friend_number) != NULL) {
+    if (get_call(session, friend_number) != nullptr) {
         LOGGER_ERROR(session->messenger->log, "Already in a call");
         pthread_mutex_unlock(session->mutex);
         return -1;
@@ -187,7 +187,7 @@ int msi_invite(MSISession *session, MSICall **call, uint32_t friend_number, uint
 
     (*call) = new_call(session, friend_number);
 
-    if (*call == NULL) {
+    if (*call == nullptr) {
         pthread_mutex_unlock(session->mutex);
         return -1;
     }
@@ -506,8 +506,8 @@ static MSICall *get_call(MSISession *session, uint32_t friend_number)
 {
     assert(session);
 
-    if (session->calls == NULL || session->calls_tail < friend_number) {
-        return NULL;
+    if (session->calls == nullptr || session->calls_tail < friend_number) {
+        return nullptr;
     }
 
     return session->calls[friend_number];
@@ -518,28 +518,28 @@ MSICall *new_call(MSISession *session, uint32_t friend_number)
 
     MSICall *rc = (MSICall *)calloc(sizeof(MSICall), 1);
 
-    if (rc == NULL) {
-        return NULL;
+    if (rc == nullptr) {
+        return nullptr;
     }
 
     rc->session = session;
     rc->friend_number = friend_number;
 
-    if (session->calls == NULL) { /* Creating */
+    if (session->calls == nullptr) { /* Creating */
         session->calls = (MSICall **)calloc(sizeof(MSICall *), friend_number + 1);
 
-        if (session->calls == NULL) {
+        if (session->calls == nullptr) {
             free(rc);
-            return NULL;
+            return nullptr;
         }
 
         session->calls_tail = session->calls_head = friend_number;
     } else if (session->calls_tail < friend_number) { /* Appending */
         MSICall **tmp = (MSICall **)realloc(session->calls, sizeof(MSICall *) * (friend_number + 1));
 
-        if (tmp == NULL) {
+        if (tmp == nullptr) {
             free(rc);
-            return NULL;
+            return nullptr;
         }
 
         session->calls = tmp;
@@ -548,7 +548,7 @@ MSICall *new_call(MSISession *session, uint32_t friend_number)
         uint32_t i = session->calls_tail + 1;
 
         for (; i < friend_number; i ++) {
-            session->calls[i] = NULL;
+            session->calls[i] = nullptr;
         }
 
         rc->prev = session->calls[session->calls_tail];
@@ -567,7 +567,7 @@ MSICall *new_call(MSISession *session, uint32_t friend_number)
 void kill_call(MSICall *call)
 {
     /* Assume that session mutex is locked */
-    if (call == NULL) {
+    if (call == nullptr) {
         return;
     }
 
@@ -594,7 +594,7 @@ void kill_call(MSICall *call)
         goto CLEAR_CONTAINER;
     }
 
-    session->calls[call->friend_number] = NULL;
+    session->calls[call->friend_number] = nullptr;
     free(call);
     return;
 
@@ -602,7 +602,7 @@ CLEAR_CONTAINER:
     session->calls_head = session->calls_tail = 0;
     free(session->calls);
     free(call);
-    session->calls = NULL;
+    session->calls = nullptr;
 }
 void on_peer_status(Messenger *m, uint32_t friend_number, uint8_t status, void *data)
 {
@@ -616,7 +616,7 @@ void on_peer_status(Messenger *m, uint32_t friend_number, uint8_t status, void *
             pthread_mutex_lock(session->mutex);
             MSICall *call = get_call(session, friend_number);
 
-            if (call == NULL) {
+            if (call == nullptr) {
                 pthread_mutex_unlock(session->mutex);
                 return;
             }
@@ -810,7 +810,7 @@ void handle_msi_packet(Messenger *m, uint32_t friend_number, const uint8_t *data
     pthread_mutex_lock(session->mutex);
     MSICall *call = get_call(session, friend_number);
 
-    if (call == NULL) {
+    if (call == nullptr) {
         if (msg.request.value != requ_init) {
             send_error(m, friend_number, msi_EStrayMessage);
             pthread_mutex_unlock(session->mutex);
@@ -819,7 +819,7 @@ void handle_msi_packet(Messenger *m, uint32_t friend_number, const uint8_t *data
 
         call = new_call(session, friend_number);
 
-        if (call == NULL) {
+        if (call == nullptr) {
             send_error(m, friend_number, msi_ESystem);
             pthread_mutex_unlock(session->mutex);
             return;
diff --git a/toxav/ring_buffer.c b/toxav/ring_buffer.c
index c60c21f2..d3f013c6 100644
--- a/toxav/ring_buffer.c
+++ b/toxav/ring_buffer.c
@@ -21,6 +21,8 @@
  */
 #include "ring_buffer.h"
 
+#include "../toxcore/ccompat.h"
+
 #include <stdlib.h>
 
 struct RingBuffer {
@@ -46,7 +48,7 @@ bool rb_empty(const RingBuffer *b)
  */
 void *rb_write(RingBuffer *b, void *p)
 {
-    void *rc = NULL;
+    void *rc = nullptr;
 
     if ((b->end + 1) % b->size == b->start) { /* full */
         rc = b->data[b->start];
@@ -65,7 +67,7 @@ void *rb_write(RingBuffer *b, void *p)
 bool rb_read(RingBuffer *b, void **p)
 {
     if (b->end == b->start) { /* Empty */
-        *p = NULL;
+        *p = nullptr;
         return false;
     }
 
@@ -79,14 +81,14 @@ RingBuffer *rb_new(int size)
     RingBuffer *buf = (RingBuffer *)calloc(sizeof(RingBuffer), 1);
 
     if (!buf) {
-        return NULL;
+        return nullptr;
     }
 
     buf->size = size + 1; /* include empty elem */
 
     if (!(buf->data = (void **)calloc(buf->size, sizeof(void *)))) {
         free(buf);
-        return NULL;
+        return nullptr;
     }
 
     return buf;
diff --git a/toxav/rtp.c b/toxav/rtp.c
index 1e07516c..01d4258a 100644
--- a/toxav/rtp.c
+++ b/toxav/rtp.c
@@ -49,7 +49,7 @@ RTPSession *rtp_new(int payload_type, Messenger *m, uint32_t friendnumber,
 
     if (!retu) {
         LOGGER_WARNING(m->log, "Alloc failed! Program might misbehave!");
-        return NULL;
+        return nullptr;
     }
 
     retu->ssrc = random_u32();
@@ -67,7 +67,7 @@ RTPSession *rtp_new(int payload_type, Messenger *m, uint32_t friendnumber,
     if (-1 == rtp_allow_receiving(retu)) {
         LOGGER_WARNING(m->log, "Failed to start rtp receiving mode");
         free(retu);
-        return NULL;
+        return nullptr;
     }
 
     return retu;
@@ -85,7 +85,7 @@ void rtp_kill(RTPSession *session)
 }
 int rtp_allow_receiving(RTPSession *session)
 {
-    if (session == NULL) {
+    if (session == nullptr) {
         return -1;
     }
 
@@ -100,11 +100,11 @@ int rtp_allow_receiving(RTPSession *session)
 }
 int rtp_stop_receiving(RTPSession *session)
 {
-    if (session == NULL) {
+    if (session == nullptr) {
         return -1;
     }
 
-    m_callback_rtp_packet(session->m, session->friend_number, session->payload_type, NULL, NULL);
+    m_callback_rtp_packet(session->m, session->friend_number, session->payload_type, nullptr, nullptr);
 
     LOGGER_DEBUG(session->m->log, "Stopped receiving on session: %p", session);
     return 0;
@@ -286,7 +286,7 @@ int handle_rtp_packet(Messenger *m, uint32_t friendnumber, const uint8_t *data,
                 free(session->mp);
             }
 
-            session->mp = NULL;
+            session->mp = nullptr;
         }
 
         /* The message came in the allowed time;
@@ -341,7 +341,7 @@ int handle_rtp_packet(Messenger *m, uint32_t friendnumber, const uint8_t *data,
                     free(session->mp);
                 }
 
-                session->mp = NULL;
+                session->mp = nullptr;
             }
         } else {
             /* Second case */
@@ -368,7 +368,7 @@ int handle_rtp_packet(Messenger *m, uint32_t friendnumber, const uint8_t *data,
                 free(session->mp);
             }
 
-            session->mp = NULL;
+            session->mp = nullptr;
             goto NEW_MULTIPARTED;
         }
     } else {
diff --git a/toxav/toxav.c b/toxav/toxav.c
index c021747a..c48fc192 100644
--- a/toxav/toxav.c
+++ b/toxav/toxav.c
@@ -110,10 +110,10 @@ void call_kill_transmission(ToxAVCall *call);
 ToxAV *toxav_new(Tox *tox, TOXAV_ERR_NEW *error)
 {
     TOXAV_ERR_NEW rc = TOXAV_ERR_NEW_OK;
-    ToxAV *av = NULL;
+    ToxAV *av = nullptr;
     Messenger *m = (Messenger *)tox;
 
-    if (tox == NULL) {
+    if (tox == nullptr) {
         rc = TOXAV_ERR_NEW_NULL;
         goto END;
     }
@@ -125,7 +125,7 @@ ToxAV *toxav_new(Tox *tox, TOXAV_ERR_NEW *error)
 
     av = (ToxAV *)calloc(sizeof(ToxAV), 1);
 
-    if (av == NULL) {
+    if (av == nullptr) {
         LOGGER_WARNING(m->log, "Allocation failed!");
         rc = TOXAV_ERR_NEW_MALLOC;
         goto END;
@@ -140,7 +140,7 @@ ToxAV *toxav_new(Tox *tox, TOXAV_ERR_NEW *error)
     av->m = m;
     av->msi = msi_new(av->m);
 
-    if (av->msi == NULL) {
+    if (av->msi == nullptr) {
         pthread_mutex_destroy(av->mutex);
         rc = TOXAV_ERR_NEW_MALLOC;
         goto END;
@@ -164,14 +164,14 @@ END:
 
     if (rc != TOXAV_ERR_NEW_OK) {
         free(av);
-        av = NULL;
+        av = nullptr;
     }
 
     return av;
 }
 void toxav_kill(ToxAV *av)
 {
-    if (av == NULL) {
+    if (av == nullptr) {
         return;
     }
 
@@ -189,7 +189,7 @@ void toxav_kill(ToxAV *av)
 
         while (it) {
             call_kill_transmission(it);
-            it->msi_call = NULL; /* msi_kill() frees the call's msi_call handle; which causes #278 */
+            it->msi_call = nullptr; /* msi_kill() frees the call's msi_call handle; which causes #278 */
             it = call_remove(it); /* This will eventually free av->calls */
         }
     }
@@ -212,7 +212,7 @@ void toxav_iterate(ToxAV *av)
 {
     pthread_mutex_lock(av->mutex);
 
-    if (av->calls == NULL) {
+    if (av->calls == nullptr) {
         pthread_mutex_unlock(av->mutex);
         return;
     }
@@ -279,7 +279,7 @@ bool toxav_call(ToxAV *av, uint32_t friend_number, uint32_t audio_bit_rate, uint
 
     call = call_new(av, friend_number, &rc);
 
-    if (call == NULL) {
+    if (call == nullptr) {
         goto END;
     }
 
@@ -337,7 +337,7 @@ bool toxav_answer(ToxAV *av, uint32_t friend_number, uint32_t audio_bit_rate, ui
 
     call = call_get(av, friend_number);
 
-    if (call == NULL) {
+    if (call == nullptr) {
         rc = TOXAV_ERR_ANSWER_FRIEND_NOT_CALLING;
         goto END;
     }
@@ -388,7 +388,7 @@ bool toxav_call_control(ToxAV *av, uint32_t friend_number, TOXAV_CALL_CONTROL co
 
     call = call_get(av, friend_number);
 
-    if (call == NULL || (!call->active && control != TOXAV_CALL_CONTROL_CANCEL)) {
+    if (call == nullptr || (!call->active && control != TOXAV_CALL_CONTROL_CANCEL)) {
         rc = TOXAV_ERR_CALL_CONTROL_FRIEND_NOT_IN_CALL;
         goto END;
     }
@@ -443,7 +443,7 @@ bool toxav_call_control(ToxAV *av, uint32_t friend_number, TOXAV_CALL_CONTROL co
                 goto END;
             }
 
-            call->msi_call = NULL;
+            call->msi_call = nullptr;
             pthread_mutex_unlock(call->mutex);
 
             /* No mather the case, terminate the call */
@@ -545,7 +545,7 @@ bool toxav_audio_set_bit_rate(ToxAV *av, uint32_t friend_number, uint32_t audio_
     pthread_mutex_lock(av->mutex);
     call = call_get(av, friend_number);
 
-    if (call == NULL || !call->active || call->msi_call->state != msi_CallActive) {
+    if (call == nullptr || !call->active || call->msi_call->state != msi_CallActive) {
         pthread_mutex_unlock(av->mutex);
         rc = TOXAV_ERR_BIT_RATE_SET_FRIEND_NOT_IN_CALL;
         goto END;
@@ -617,7 +617,7 @@ bool toxav_video_set_bit_rate(ToxAV *av, uint32_t friend_number, uint32_t video_
     pthread_mutex_lock(av->mutex);
     call = call_get(av, friend_number);
 
-    if (call == NULL || !call->active || call->msi_call->state != msi_CallActive) {
+    if (call == nullptr || !call->active || call->msi_call->state != msi_CallActive) {
         pthread_mutex_unlock(av->mutex);
         rc = TOXAV_ERR_BIT_RATE_SET_FRIEND_NOT_IN_CALL;
         goto END;
@@ -702,7 +702,7 @@ bool toxav_audio_send_frame(ToxAV *av, uint32_t friend_number, const int16_t *pc
 
     call = call_get(av, friend_number);
 
-    if (call == NULL || !call->active || call->msi_call->state != msi_CallActive) {
+    if (call == nullptr || !call->active || call->msi_call->state != msi_CallActive) {
         pthread_mutex_unlock(av->mutex);
         rc = TOXAV_ERR_SEND_FRAME_FRIEND_NOT_IN_CALL;
         goto END;
@@ -719,7 +719,7 @@ bool toxav_audio_send_frame(ToxAV *av, uint32_t friend_number, const int16_t *pc
     pthread_mutex_lock(call->mutex_audio);
     pthread_mutex_unlock(av->mutex);
 
-    if (pcm == NULL) {
+    if (pcm == nullptr) {
         pthread_mutex_unlock(call->mutex_audio);
         rc = TOXAV_ERR_SEND_FRAME_NULL;
         goto END;
@@ -787,7 +787,7 @@ bool toxav_video_send_frame(ToxAV *av, uint32_t friend_number, uint16_t width, u
 
     call = call_get(av, friend_number);
 
-    if (call == NULL || !call->active || call->msi_call->state != msi_CallActive) {
+    if (call == nullptr || !call->active || call->msi_call->state != msi_CallActive) {
         pthread_mutex_unlock(av->mutex);
         rc = TOXAV_ERR_SEND_FRAME_FRIEND_NOT_IN_CALL;
         goto END;
@@ -804,7 +804,7 @@ bool toxav_video_send_frame(ToxAV *av, uint32_t friend_number, uint16_t width, u
     pthread_mutex_lock(call->mutex_video);
     pthread_mutex_unlock(av->mutex);
 
-    if (y == NULL || u == NULL || v == NULL) {
+    if (y == nullptr || u == nullptr || v == nullptr) {
         pthread_mutex_unlock(call->mutex_video);
         rc = TOXAV_ERR_SEND_FRAME_NULL;
         goto END;
@@ -844,7 +844,7 @@ bool toxav_video_send_frame(ToxAV *av, uint32_t friend_number, uint16_t width, u
     ++call->video.second->frame_counter;
 
     { /* Send frames */
-        vpx_codec_iter_t iter = NULL;
+        vpx_codec_iter_t iter = nullptr;
         const vpx_codec_cx_pkt_t *pkt;
 
         while ((pkt = vpx_codec_get_cx_data(call->video.second->encoder, &iter))) {
@@ -948,9 +948,9 @@ int callback_invite(void *toxav_inst, MSICall *call)
     ToxAV *toxav = (ToxAV *)toxav_inst;
     pthread_mutex_lock(toxav->mutex);
 
-    ToxAVCall *av_call = call_new(toxav, call->friend_number, NULL);
+    ToxAVCall *av_call = call_new(toxav, call->friend_number, nullptr);
 
-    if (av_call == NULL) {
+    if (av_call == nullptr) {
         LOGGER_WARNING(toxav->m->log, "Failed to initialize call...");
         pthread_mutex_unlock(toxav->mutex);
         return -1;
@@ -978,7 +978,7 @@ int callback_start(void *toxav_inst, MSICall *call)
 
     ToxAVCall *av_call = call_get(toxav, call->friend_number);
 
-    if (av_call == NULL) {
+    if (av_call == nullptr) {
         /* Should this ever happen? */
         pthread_mutex_unlock(toxav->mutex);
         return -1;
@@ -1083,7 +1083,7 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
 {
     /* Assumes mutex locked */
     TOXAV_ERR_CALL rc = TOXAV_ERR_CALL_OK;
-    ToxAVCall *call = NULL;
+    ToxAVCall *call = nullptr;
 
     if (m_friend_exists(av->m, friend_number) == 0) {
         rc = TOXAV_ERR_CALL_FRIEND_NOT_FOUND;
@@ -1095,7 +1095,7 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
         goto END;
     }
 
-    if (call_get(av, friend_number) != NULL) {
+    if (call_get(av, friend_number) != nullptr) {
         rc = TOXAV_ERR_CALL_FRIEND_ALREADY_IN_CALL;
         goto END;
     }
@@ -1103,7 +1103,7 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
 
     call = (ToxAVCall *)calloc(sizeof(ToxAVCall), 1);
 
-    if (call == NULL) {
+    if (call == nullptr) {
         rc = TOXAV_ERR_CALL_MALLOC;
         goto END;
     }
@@ -1111,12 +1111,12 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
     call->av = av;
     call->friend_number = friend_number;
 
-    if (av->calls == NULL) { /* Creating */
+    if (av->calls == nullptr) { /* Creating */
         av->calls = (ToxAVCall **)calloc(sizeof(ToxAVCall *), friend_number + 1);
 
-        if (av->calls == NULL) {
+        if (av->calls == nullptr) {
             free(call);
-            call = NULL;
+            call = nullptr;
             rc = TOXAV_ERR_CALL_MALLOC;
             goto END;
         }
@@ -1125,9 +1125,9 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
     } else if (av->calls_tail < friend_number) { /* Appending */
         ToxAVCall **tmp = (ToxAVCall **)realloc(av->calls, sizeof(ToxAVCall *) * (friend_number + 1));
 
-        if (tmp == NULL) {
+        if (tmp == nullptr) {
             free(call);
-            call = NULL;
+            call = nullptr;
             rc = TOXAV_ERR_CALL_MALLOC;
             goto END;
         }
@@ -1138,7 +1138,7 @@ ToxAVCall *call_new(ToxAV *av, uint32_t friend_number, TOXAV_ERR_CALL *error)
         uint32_t i = av->calls_tail + 1;
 
         for (; i < friend_number; i ++) {
-            av->calls[i] = NULL;
+            av->calls[i] = nullptr;
         }
 
         call->prev = av->calls[av->calls_tail];
@@ -1164,16 +1164,16 @@ END:
 ToxAVCall *call_get(ToxAV *av, uint32_t friend_number)
 {
     /* Assumes mutex locked */
-    if (av->calls == NULL || av->calls_tail < friend_number) {
-        return NULL;
+    if (av->calls == nullptr || av->calls_tail < friend_number) {
+        return nullptr;
     }
 
     return av->calls[friend_number];
 }
 ToxAVCall *call_remove(ToxAVCall *call)
 {
-    if (call == NULL) {
-        return NULL;
+    if (call == nullptr) {
+        return nullptr;
     }
 
     uint32_t friend_number = call->friend_number;
@@ -1186,7 +1186,7 @@ ToxAVCall *call_remove(ToxAVCall *call)
      * removed from the msi call.
      */
     if (call->msi_call) {
-        call->msi_call->av_call = NULL;
+        call->msi_call->av_call = nullptr;
     }
 
     free(call);
@@ -1207,21 +1207,21 @@ ToxAVCall *call_remove(ToxAVCall *call)
         goto CLEAR;
     }
 
-    av->calls[friend_number] = NULL;
+    av->calls[friend_number] = nullptr;
     return next;
 
 CLEAR:
     av->calls_head = av->calls_tail = 0;
     free(av->calls);
-    av->calls = NULL;
+    av->calls = nullptr;
 
-    return NULL;
+    return nullptr;
 }
 bool call_prepare_transmission(ToxAVCall *call)
 {
     /* Assumes mutex locked */
 
-    if (call == NULL) {
+    if (call == nullptr) {
         return false;
     }
 
@@ -1292,12 +1292,12 @@ FAILURE:
     bwc_kill(call->bwc);
     rtp_kill(call->audio.first);
     ac_kill(call->audio.second);
-    call->audio.first = NULL;
-    call->audio.second = NULL;
+    call->audio.first = nullptr;
+    call->audio.second = nullptr;
     rtp_kill(call->video.first);
     vc_kill(call->video.second);
-    call->video.first = NULL;
-    call->video.second = NULL;
+    call->video.first = nullptr;
+    call->video.second = nullptr;
     pthread_mutex_destroy(call->mutex);
 FAILURE_2:
     pthread_mutex_destroy(call->mutex_video);
@@ -1307,7 +1307,7 @@ FAILURE_3:
 }
 void call_kill_transmission(ToxAVCall *call)
 {
-    if (call == NULL || call->active == 0) {
+    if (call == nullptr || call->active == 0) {
         return;
     }
 
@@ -1324,13 +1324,13 @@ void call_kill_transmission(ToxAVCall *call)
 
     rtp_kill(call->audio.first);
     ac_kill(call->audio.second);
-    call->audio.first = NULL;
-    call->audio.second = NULL;
+    call->audio.first = nullptr;
+    call->audio.second = nullptr;
 
     rtp_kill(call->video.first);
     vc_kill(call->video.second);
-    call->video.first = NULL;
-    call->video.second = NULL;
+    call->video.first = nullptr;
+    call->video.second = nullptr;
 
     pthread_mutex_destroy(call->mutex_audio);
     pthread_mutex_destroy(call->mutex_video);
diff --git a/toxav/video.c b/toxav/video.c
index c84e89f7..eee542a2 100644
--- a/toxav/video.c
+++ b/toxav/video.c
@@ -43,20 +43,20 @@ VCSession *vc_new(Logger *log, ToxAV *av, uint32_t friend_number, toxav_video_re
 
     if (!vc) {
         LOGGER_WARNING(log, "Allocation failed! Application might misbehave!");
-        return NULL;
+        return nullptr;
     }
 
     if (create_recursive_mutex(vc->queue_mutex) != 0) {
         LOGGER_WARNING(log, "Failed to create recursive mutex!");
         free(vc);
-        return NULL;
+        return nullptr;
     }
 
     if (!(vc->vbuf_raw = rb_new(VIDEO_DECODE_BUFFER_SIZE))) {
         goto BASE_CLEANUP;
     }
 
-    rc = vpx_codec_dec_init(vc->decoder, VIDEO_CODEC_DECODER_INTERFACE, NULL, 0);
+    rc = vpx_codec_dec_init(vc->decoder, VIDEO_CODEC_DECODER_INTERFACE, nullptr, 0);
 
     if (rc != VPX_CODEC_OK) {
         LOGGER_ERROR(log, "Init video_decoder failed: %s", vpx_codec_err_to_string(rc));
@@ -118,7 +118,7 @@ BASE_CLEANUP:
     pthread_mutex_destroy(vc->queue_mutex);
     rb_kill((RingBuffer *)vc->vbuf_raw);
     free(vc);
-    return NULL;
+    return nullptr;
 }
 void vc_kill(VCSession *vc)
 {
@@ -157,13 +157,13 @@ void vc_iterate(VCSession *vc)
     if (rb_read((RingBuffer *)vc->vbuf_raw, (void **)&p)) {
         pthread_mutex_unlock(vc->queue_mutex);
 
-        rc = vpx_codec_decode(vc->decoder, p->data, p->len, NULL, MAX_DECODE_TIME_US);
+        rc = vpx_codec_decode(vc->decoder, p->data, p->len, nullptr, MAX_DECODE_TIME_US);
         free(p);
 
         if (rc != VPX_CODEC_OK) {
             LOGGER_ERROR(vc->log, "Error decoding video: %s", vpx_codec_err_to_string(rc));
         } else {
-            vpx_codec_iter_t iter = NULL;
+            vpx_codec_iter_t iter = nullptr;
             vpx_image_t *dest = vpx_codec_get_frame(vc->decoder, &iter);
 
             /* Play decoded images */