diff --git a/ultragrid/src/audio/capture/coreaudio.c b/ultragrid/src/audio/capture/coreaudio.c
index 082475e5e..cd51ef9f5 100644
--- a/ultragrid/src/audio/capture/coreaudio.c
+++ b/ultragrid/src/audio/capture/coreaudio.c
@@ -51,11 +51,13 @@
 #ifdef HAVE_COREAUDIO
 
 #include "audio/audio.h"
+#include "audio/utils.h"
 #include "audio/capture/coreaudio.h" 
 #include "utils/ring_buffer.h"
 #include "debug.h"
 #include <stdlib.h>
 #include <AudioUnit/AudioUnit.h>
+#include <QuickTime/QuickTime.h>
 #include <pthread.h>
 
 #ifdef HAVE_SPEEX
@@ -141,6 +143,7 @@ static OSStatus InputProc(void *inRefCon,
                 UInt32 inNumberFrames,
                 AudioBufferList * ioData)
 {
+	UNUSED(ioData);
         struct state_ca_capture * s = (struct state_ca_capture *) inRefCon;
 
         OSStatus err =noErr;
@@ -181,7 +184,7 @@ static OSStatus InputProc(void *inRefCon,
                         pthread_cond_signal(&s->cv);
                 pthread_mutex_unlock(&s->lock);
         } else {
-                fprintf(stderr, "[CoreAudio] writing buffer caused error %i.\n", err);
+                fprintf(stderr, "[CoreAudio] writing buffer caused error %i.\n", (int) err);
         }
 
         return err;
@@ -190,7 +193,6 @@ static OSStatus InputProc(void *inRefCon,
 void audio_cap_ca_help(void)
 {
         OSErr ret;
-        AudioDeviceID device;
         AudioDeviceID *dev_ids;
         int dev_items;
         int i;
@@ -210,7 +212,7 @@ void audio_cap_ca_help(void)
                 
                 size = sizeof(name);
                 ret = AudioDeviceGetProperty(dev_ids[i], 0, 0, kAudioDevicePropertyDeviceName, &size, name);
-                fprintf(stderr,"\tcoreaudio:%d : %s\n", dev_ids[i], name);
+                fprintf(stderr,"\tcoreaudio:%d : %s\n", (int) dev_ids[i], name);
         }
         free(dev_ids);
 
@@ -371,7 +373,6 @@ void * audio_cap_ca_init(char *cfg)
 
         {
                 AudioStreamBasicDescription desc;
-                AURenderCallbackStruct  renderStruct;
 
                 size = sizeof(desc);
                 ret = AudioUnitGetProperty(s->auHALComponentInstance, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input,
@@ -465,7 +466,7 @@ struct audio_frame *audio_cap_ca_read(void *state)
 
 void audio_cap_ca_finish(void *state)
 {
-        struct state_ca_capture *s = (struct state_ca_capture *) state;
+        UNUSED(state);
 }
 
 void audio_cap_ca_done(void *state)
diff --git a/ultragrid/src/audio/playback/coreaudio.c b/ultragrid/src/audio/playback/coreaudio.c
index fcf43ecbc..44301fc11 100644
--- a/ultragrid/src/audio/playback/coreaudio.c
+++ b/ultragrid/src/audio/playback/coreaudio.c
@@ -84,6 +84,10 @@ static OSStatus theRenderProc(void *inRefCon,
                               UInt32 inBusNumber, UInt32 inNumFrames,
                               AudioBufferList *ioData)
 {
+        UNUSED(inActionFlags);
+        UNUSED(inTimeStamp);
+        UNUSED(inBusNumber);
+
         struct state_ca_playback * s = (struct state_ca_playback *) inRefCon;
         int write_bytes = inNumFrames * s->audio_packet_size;
         int ret;
@@ -169,7 +173,6 @@ error:
 void audio_play_ca_help(void)
 {
         OSErr ret;
-        AudioDeviceID device;
         AudioDeviceID *dev_ids;
         int dev_items;
         int i;
@@ -189,7 +192,7 @@ void audio_play_ca_help(void)
                 
                 size = sizeof(name);
                 ret = AudioDeviceGetProperty(dev_ids[i], 0, 0, kAudioDevicePropertyDeviceName, &size, name);
-                fprintf(stderr,"\tcoreaudio:%d : %s\n", dev_ids[i], name);
+                fprintf(stderr,"\tcoreaudio:%d : %s\n", (int) dev_ids[i], name);
         }
         free(dev_ids);
 
diff --git a/ultragrid/src/compat/platform_time.c b/ultragrid/src/compat/platform_time.c
index 58a30e41b..a195d48d8 100644
--- a/ultragrid/src/compat/platform_time.c
+++ b/ultragrid/src/compat/platform_time.c
@@ -58,6 +58,8 @@
 #include <mach/mach.h>
 
 int clock_gettime(int unused, struct timespec *ts) {
+	UNUSED(unused);
+
         clock_serv_t cclock;
         mach_timespec_t mts;
 
@@ -66,6 +68,8 @@ int clock_gettime(int unused, struct timespec *ts) {
         mach_port_deallocate(mach_task_self(), cclock);
         ts->tv_sec = mts.tv_sec;
         ts->tv_nsec = mts.tv_nsec;
+
+	return 0;
 }
 #endif
 
diff --git a/ultragrid/src/rtp/decoders.c b/ultragrid/src/rtp/decoders.c
index 3b84f47d1..39a024fc1 100644
--- a/ultragrid/src/rtp/decoders.c
+++ b/ultragrid/src/rtp/decoders.c
@@ -233,7 +233,7 @@ void decoder_destroy(struct state_decoder *decoder)
 static codec_t choose_codec_and_decoder(struct state_decoder * const decoder, struct video_desc desc,
                                 codec_t *in_codec, decoder_t *decode_line)
 {
-        codec_t out_codec;
+        codec_t out_codec = (codec_t) -1;
         *decode_line = NULL;
         *in_codec = desc.color_spec;
         
diff --git a/ultragrid/src/rtp/pbuf.c b/ultragrid/src/rtp/pbuf.c
index 955bc9c1f..9b8e6675f 100644
--- a/ultragrid/src/rtp/pbuf.c
+++ b/ultragrid/src/rtp/pbuf.c
@@ -382,6 +382,9 @@ audio_pbuf_decode(struct pbuf *playout_buf, struct timeval curr_time,
         
         while (curr != NULL) {
                 if (!curr->decoded && frame_complete(curr)) {   // FIXME: figure out then right frames ordering (if needed) - se pbuf_decode
+                        int total_channels = 0, bps,
+                                sample_rate;
+                        int channel;
                         
                         curr->decoded = 1;
                                 
@@ -391,13 +394,12 @@ audio_pbuf_decode(struct pbuf *playout_buf, struct timeval curr_time,
                                 audio_payload_hdr_t *hdr = 
                                         (audio_payload_hdr_t *) cdata->data->data;
                                         
-                                int total_channels, bps,
-                                        sample_rate;
-                                int channel;
-                                
+                                /* we receive last channel first (with m bit, last packet) */
+                                /* thus can be set only with m-bit packet */
                                 if(cdata->data->m) {
                                         total_channels = ((ntohl(hdr->substream_bufnum) >> 22) & 0x3ff) + 1;
                                 }
+                                assert(total_channels > 0);
 
                                 channel = (ntohl(hdr->substream_bufnum) >> 22) & 0x3ff;
                                 sample_rate = ntohl(hdr->quant_sample_rate) & 0x3fffff;
diff --git a/ultragrid/src/tile.c b/ultragrid/src/tile.c
index 3c3d7dbe3..a2a8afd11 100644
--- a/ultragrid/src/tile.c
+++ b/ultragrid/src/tile.c
@@ -63,7 +63,7 @@ void vf_split(struct video_frame *out, struct video_frame *src,
 {
         unsigned int               tile_idx, line_idx;
         struct tile        *cur_tiles;
-        unsigned int               tile_line;
+        unsigned int               tile_line = 0;
 
         out->color_spec = src->color_spec;
         out->fps = src->fps;
diff --git a/ultragrid/src/transmit.c b/ultragrid/src/transmit.c
index 7ecd3c216..ed1d50f9f 100644
--- a/ultragrid/src/transmit.c
+++ b/ultragrid/src/transmit.c
@@ -208,8 +208,8 @@ tx_send_base(struct tx *tx, struct tile *tile, struct rtp *rtp_session,
         long delta;
         uint32_t tmp;
         unsigned int fps, fpsd, fd, fi;
-        struct xor_session **xor;
-        int *xor_pkts;
+        struct xor_session **xor = NULL;
+        int *xor_pkts = NULL;
         int mult_pos[FEC_MAX_MULT];
         int mult_index = 0;
         int mult_first_sent = 0;
diff --git a/ultragrid/src/video_capture/decklink.cpp b/ultragrid/src/video_capture/decklink.cpp
index 0e455a113..7599c7cd7 100644
--- a/ultragrid/src/video_capture/decklink.cpp
+++ b/ultragrid/src/video_capture/decklink.cpp
@@ -722,7 +722,7 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                 result = deckLink->QueryInterface(IID_IDeckLinkInput, (void**)&deckLinkInput);
                                 if (result != S_OK)
                                 {
-                                        printf("Could not obtain the IDeckLinkInput interface - result = %08x\n", result);
+                                        printf("Could not obtain the IDeckLinkInput interface - result = %08x\n", (int) result);
                                         goto error;
                                 }
 
@@ -732,7 +732,7 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                 result = deckLinkInput->GetDisplayModeIterator(&displayModeIterator);
                                 if (result != S_OK)
                                 {
-                                        printf("Could not obtain the video input display mode iterator - result = %08x\n", result);
+                                        printf("Could not obtain the video input display mode iterator - result = %08x\n", (int) result);
                                         goto error;
                                 }
 
@@ -765,7 +765,7 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                         if (result != S_OK)
                                         {
                                                 printf("Could not query device attributes.\n");
-                                                printf("Could not enable video input: %08x\n", result);
+                                                printf("Could not enable video input: %08x\n", (int) result);
                                                 goto error;
                                         }
 
@@ -790,7 +790,7 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                         if (result != S_OK)
                                         {
                                                 printf("You have required invalid video mode and pixel format combination.\n");
-                                                printf("Could not enable video input: %08x\n", result);
+                                                printf("Could not enable video input: %08x\n", (int) result);
                                                 goto error;
                                         }
 
@@ -798,7 +798,7 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                         result = deckLinkInput->QueryInterface(IID_IDeckLinkConfiguration, (void**)&deckLinkConfiguration);
                                         if (result != S_OK)
                                         {
-                                                printf("Could not obtain the IDeckLinkConfiguration interface: %08x\n", result);
+                                                printf("Could not obtain the IDeckLinkConfiguration interface: %08x\n", (int) result);
                                                 goto error;
                                         }
 
@@ -849,12 +849,12 @@ vidcap_decklink_init(char *fmt, unsigned int flags)
                                         result = deckLinkInput->StartStreams();
                                         if (result != S_OK)
                                         {
-                                                printf("Could not start stream: %08x\n", result);
+                                                printf("Could not start stream: %08x\n", (int) result);
                                                 goto error;
                                         }
 
                                 }else{
-                                        printf("Could not : %08x\n", result);
+                                        printf("Could not : %08x\n", (int) result);
                                         goto error;
                                 }
 
@@ -945,7 +945,7 @@ vidcap_decklink_done(void *state)
 		result = s->state[i].deckLinkInput->StopStreams();
 		if (result != S_OK)
 		{
-			printf("Could not stop stream: %08x\n", result);
+			printf("Could not stop stream: %08x\n", (int) result);
 		}
 
 		if(s->state[i].deckLinkInput != NULL)
@@ -1168,7 +1168,7 @@ print_output_modes (IDeckLink* deckLink)
 	result = deckLink->QueryInterface(IID_IDeckLinkOutput, (void**)&deckLinkOutput);
 	if (result != S_OK)
 	{
-		fprintf(stderr, "Could not obtain the IDeckLinkOutput interface - result = %08x\n", result);
+		fprintf(stderr, "Could not obtain the IDeckLinkOutput interface - result = %08x\n", (int) result);
 		goto bail;
 	}
 	
@@ -1176,7 +1176,7 @@ print_output_modes (IDeckLink* deckLink)
 	result = deckLinkOutput->GetDisplayModeIterator(&displayModeIterator);
 	if (result != S_OK)
 	{
-		fprintf(stderr, "Could not obtain the video output display mode iterator - result = %08x\n", result);
+		fprintf(stderr, "Could not obtain the video output display mode iterator - result = %08x\n", (int) result);
 		goto bail;
 	}
 	
diff --git a/ultragrid/src/video_capture/quicktime.c b/ultragrid/src/video_capture/quicktime.c
index 9815b6232..1d3cb5d0e 100644
--- a/ultragrid/src/video_capture/quicktime.c
+++ b/ultragrid/src/video_capture/quicktime.c
@@ -256,7 +256,7 @@ static OSErr MinimalSGSettingsDialog(SeqGrabComponent seqGrab,
 }
 
 static void 
-nprintf(unsigned char *str)
+nprintf(char *str)
 {
         char tmp[((int)str[0]) + 1];
 
@@ -266,7 +266,7 @@ nprintf(unsigned char *str)
 }
 
 static void 
-shrink(unsigned char *str)
+shrink(char *str)
 {
         int i, j;
         j=1;
@@ -285,12 +285,12 @@ shrink(unsigned char *str)
         str[0] = j-1;
 }
 
-static unsigned char * 
-shrink2(unsigned char *str)
+static char * 
+shrink2(char *str)
 {
         int i, j;
         int len = strlen((char*)str);
-        str = (unsigned char*)strdup((char*)str);
+        str = strdup((char*)str);
         j=0;
         for(i=0; i < len; i++) {
            while((str[i] == '\t' ||
@@ -312,13 +312,13 @@ shrink2(unsigned char *str)
  * Blackmagic 2 HD 1080
  * ....
  */ 
-static unsigned char * 
-delCardIndicesCard(unsigned char *str)
+static char * 
+delCardIndicesCard(char *str)
 {
-        if(strncmp(str, "Blackmagic", strlen("Blackmagic")) == 0) {
+        if(strncmp((char *) str, "Blackmagic", strlen("Blackmagic")) == 0) {
                 if(isdigit(str[strlen("Blackmagic") + 1])) { // Eg. Blackmagic X ...
                         int len = 
-                                strlen(str + strlen("Blackmagic") + 2);
+                                strlen((char *) str + strlen("Blackmagic") + 2);
                         memmove(str + strlen("Blackmagic"),
                                 str + strlen("Blackmagic") + 2,
                                 len);
@@ -332,14 +332,14 @@ delCardIndicesCard(unsigned char *str)
  * ... and to its modes:
  * eg.: Blackmagic HD 1080i 50 - 8 Bit (2)
  */
-static unsigned char * 
-delCardIndicesMode(unsigned char *str)
+static char * 
+delCardIndicesMode(char *str)
 {
-        if(strncmp(str, "Blackmagic", strlen("Blackmagic")) == 0) {
-                if(str[strlen(str) - 1 - 2] == '('
-                                && isdigit(str[strlen(str) - 1 - 1])
-                                && str[strlen(str) - 1] == ')') {
-                        str[strlen(str) - 4] = '\0'; // Eg.: Blackmagic ... (x)
+        if(strncmp((char *) str, "Blackmagic", strlen("Blackmagic")) == 0) {
+                if(str[strlen((char *)str) - 1 - 2] == '('
+                                && isdigit(str[strlen((char *) str) - 1 - 1])
+                                && str[strlen((char *) str) - 1] == ')') {
+                        str[strlen((char *) str) - 4] = '\0'; // Eg.: Blackmagic ... (x)
                 }
         }
         return str;
@@ -431,7 +431,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                                 SGDeviceName *deviceEntry =
                                     &(*deviceList)->entry[i];
                                 fprintf(stdout, " Device %d: ", i);
-                                nprintf(deviceEntry->name);
+                                nprintf((char *) deviceEntry->name);
                                 if (deviceEntry->flags &
                                     sgDeviceNameFlagDeviceUnavailable) {
                                         fprintf(stdout,
@@ -451,7 +451,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                                              j++) {
                                                 fprintf(stdout, "\t");
                                                 fprintf(stdout, "- %d. ", j);
-                                                nprintf((unsigned char*)&(*inputList)->entry
+                                                nprintf((char *) &(*inputList)->entry
                                                              [j].name);
                                                 if ((i ==
                                                      (*deviceList)->selectedIndex)
@@ -469,7 +469,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                         for (i = 0; i < list->count; i++) {
                                 int fcc = list->list[i].cType;
                                 printf("\t%d) ", i);
-                                nprintf(list->list[i].typeName);
+                                nprintf((char *) list->list[i].typeName);
                                 printf(" - FCC (%c%c%c%c)",
                                        fcc >> 24,
                                        (fcc >> 16) & 0xff,
@@ -489,7 +489,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                                 SGDeviceName *deviceEntry =
                                     &(*deviceList)->entry[i];
                                 fprintf(stdout, " Device %d: ", i);
-                                nprintf(deviceEntry->name);
+                                nprintf((char *) deviceEntry->name);
                                 if (deviceEntry->flags &
                                     sgDeviceNameFlagDeviceUnavailable) {
                                         fprintf(stdout,
@@ -509,7 +509,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                                              j++) {
                                                 fprintf(stdout, "\t");
                                                 fprintf(stdout, "- %d. ", j);
-                                                nprintf((unsigned char*)&(*inputList)->entry
+                                                nprintf((char*)&(*inputList)->entry
                                                              [j].name);
                                                 if ((i ==
                                                      (*deviceList)->selectedIndex)
@@ -599,7 +599,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
 
                 SGDeviceName *deviceEntry = &(*deviceList)->entry[s->major];
                 printf("Quicktime: Setting device: ");
-                nprintf(deviceEntry->name);
+                nprintf((char *) deviceEntry->name);
                 printf("\n");
                 if (SGSetChannelDevice(s->video_channel, deviceEntry->name) !=
                     noErr) {
@@ -610,7 +610,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                 /* Select input */
                 inputList = deviceEntry->inputs;
                 printf("Quicktime: Setting input: ");
-                nprintf((unsigned char *)(&(*inputList)->entry[s->minor].name));
+                nprintf((char *)(&(*inputList)->entry[s->minor].name));
                 printf("\n");
                 if (SGSetChannelDeviceInput(s->video_channel, s->minor) !=
                     noErr) {
@@ -629,8 +629,8 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
         s->tile->height = s->bounds.bottom =
             gActiveVideoRect.bottom - gActiveVideoRect.top;
 
-        unsigned char *deviceName;
-        unsigned char *inputName;
+        char *deviceName;
+        char *inputName;
         short  inputNumber;
         TimeScale scale;
 
@@ -643,15 +643,15 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
         SGDeviceName *deviceEntry = &(*deviceList)->entry[(*deviceList)->selectedIndex];
         inputList = deviceEntry->inputs;
 
-        deviceName = deviceEntry->name;
-        inputName = (unsigned char*)&(*inputList)->entry[inputNumber].name;
+        deviceName = (char *) deviceEntry->name;
+        inputName = (char*)&(*inputList)->entry[inputNumber].name;
 
         shrink(delCardIndicesCard(deviceName));
-        shrink(delCardIndicesCard(inputName));
+        shrink(delCardIndicesMode(inputName));
 
         for(i=0; quicktime_modes[i].device != NULL; i++) {
-                unsigned char *device = shrink2(quicktime_modes[i].device);
-                unsigned char *input = shrink2(quicktime_modes[i].input);
+                char *device = shrink2(quicktime_modes[i].device);
+                char *input = shrink2(quicktime_modes[i].input);
 
                 if((strncmp((char*)device, (char*)&deviceName[1], deviceName[0])) == 0 &&
                    (strncmp((char*)input, (char*)&inputName[1], inputName[0])) == 0) {
@@ -697,7 +697,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
         }
 
         /* Set selected fmt->codec and get pixel format of that codec */
-        int pixfmt;
+        int pixfmt = -1;
         if (s->frame->color_spec != 0xffffffff) {
                 CodecNameSpecListPtr list;
                 GetCodecNameList(&list, 1);
@@ -719,6 +719,10 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                         }
                 }
         }
+        if(pixfmt == -1) {
+                fprintf(stderr, "[QuickTime] Unknown pixelformat!\n");
+                goto error;
+        }
 
         for (i = 0; codec_info[i].name != NULL; i++) {
                 if ((unsigned)pixfmt == codec_info[i].fcc) {
@@ -732,7 +736,6 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                pixfmt >> 24, (pixfmt >> 16) & 0xff, (pixfmt >> 8) & 0xff,
                (pixfmt) & 0xff);
 
-        int h_align = s->c_info->h_align;
         s->tile->data_len = vc_get_linesize(s->tile->width, s->frame->color_spec) * s->tile->height;
         s->vbuffer[0] = malloc(s->tile->data_len);
         s->vbuffer[1] = malloc(s->tile->data_len);
@@ -753,7 +756,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                 }
                 SGDeviceName *deviceEntry = &(*deviceList)->entry[s->audio_major];
                 printf("Quicktime: Setting audio device: ");
-                nprintf(deviceEntry->name);
+                nprintf((char *) deviceEntry->name);
                 printf("\n");
                 if (SGSetChannelDevice(s->audio_channel, deviceEntry->name) !=
                     noErr) {
@@ -765,7 +768,7 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                 /* Select input */
                 inputList = deviceEntry->inputs;
                 printf("Quicktime: Setting audio input: ");
-                nprintf((unsigned char *)(&(*inputList)->entry[s->audio_minor].name));
+                nprintf((char *)(&(*inputList)->entry[s->audio_minor].name));
                 printf("\n");
                 if (SGSetChannelDeviceInput(s->audio_channel, s->audio_minor) !=
                     noErr) {
@@ -773,8 +776,12 @@ static int qt_open_grabber(struct qt_grabber_state *s, char *fmt)
                         s->grab_audio = FALSE;
                         goto AFTER_AUDIO;
                 }
-                ret = SGGetSoundInputParameters(s->audio_channel, &s->audio.bps,
-                                &s->audio.ch_count, &compression);
+                short bps, ch_count;
+                ret = SGGetSoundInputParameters(s->audio_channel, &bps,
+                                &ch_count, &compression);
+                s->audio.bps = bps;
+                s->audio.ch_count = ch_count;
+
                 if(ret != noErr) {
                         fprintf(stderr, "Quicktime: failed to get audio properties");
                         s->grab_audio = FALSE;
@@ -828,6 +835,7 @@ AFTER_AUDIO:
         SGGetChannelTimeScale(s->video_channel, &scale);
         s->frame->fps = scale / 100.0;
 
+error:
         return 1;
 }
 
diff --git a/ultragrid/src/video_display/gl.c b/ultragrid/src/video_display/gl.c
index 848f09ba9..97daae41d 100644
--- a/ultragrid/src/video_display/gl.c
+++ b/ultragrid/src/video_display/gl.c
@@ -222,6 +222,10 @@ void glut_key_callback(unsigned char key, int x, int y);
 void glut_close_callback(void);
 void glut_resize_window(struct state_gl *s);
 
+#ifdef HAVE_MACOSX
+void NSApplicationLoad(void);
+#endif
+
 /**
  * Show help
  * @since 23-03-2010, xsedmik
diff --git a/ultragrid/src/video_display/quicktime.c b/ultragrid/src/video_display/quicktime.c
index b93799e5d..ea26f713b 100644
--- a/ultragrid/src/video_display/quicktime.c
+++ b/ultragrid/src/video_display/quicktime.c
@@ -246,7 +246,7 @@ void display_quicktime_reconfigure_audio(void *state, int quant_samples, int cha
                 int sample_rate);
 
 static void
-nprintf(unsigned char *str)
+nprintf(char *str)
 {
         char tmp[((int)str[0]) + 1];
 
@@ -320,7 +320,7 @@ static void reconf_common(struct state_quicktime *s)
                                                NULL,
                                                srcCopy,
                                                NULL,
-                                               (CodecFlags) NULL,
+                                               (CodecFlags) 0,
                                                codecNormalQuality, bestSpeedCodec);
                 if (ret != noErr)
                         fprintf(stderr, "Failed DecompressSequenceBeginS\n");
@@ -354,7 +354,7 @@ void display_quicktime_run(void *arg)
                                                         * the decompressor does not call the completion 
                                                         * function. 
                                                         */
-                                                       0, &ignore, -1,       
+                                                       0, &ignore, (void *) -1,       
                                                           NULL);
                         if (ret != noErr) {
                                 fprintf(stderr,
@@ -557,7 +557,7 @@ void *display_quicktime_init(char *fmt, unsigned int flags)
         struct state_quicktime *s;
         int ret;
         int i;
-        char *codec_name;
+        char *codec_name = NULL;
 
         /* Parse fmt input */
         s = (struct state_quicktime *)calloc(1, sizeof(struct state_quicktime));
@@ -788,7 +788,7 @@ void display_quicktime_audio_init(struct state_quicktime *s)
         ret = GetComponentInfo(audioComponent, 0, componentNameHandle, NULL, NULL);
         if (ret != noErr) goto audio_error;
         HLock(componentNameHandle);
-        s->audio_name = CFStringCreateWithPascalString(NULL, *componentNameHandle,
+        s->audio_name = CFStringCreateWithPascalString(NULL, (ConstStr255Param) *componentNameHandle,
                         kCFStringEncodingMacRoman);
         HUnlock(componentNameHandle);
         DisposeHandle(componentNameHandle);
@@ -892,7 +892,7 @@ int display_quicktime_reconfigure(void *state, struct video_desc desc)
         struct state_quicktime *s = (struct state_quicktime *) state;
         int i;
         int ret;
-        const char *codec_name;
+        const char *codec_name = NULL;
 
         for (i = 0; codec_info[i].name != NULL; i++) {
                 if (codec_info[i].codec == desc.color_spec) {
@@ -900,6 +900,7 @@ int display_quicktime_reconfigure(void *state, struct video_desc desc)
                         codec_name = s->cinfo->name;
                 }
         }
+	assert(codec_name != NULL);
         if(desc.color_spec == UYVY || desc.color_spec == DVS8) /* just aliases for 2vuy,
                                             * but would confuse QT */
                 codec_name = "2vuy";
@@ -1129,6 +1130,10 @@ static OSStatus theRenderProc(void *inRefCon,
                               UInt32 inBusNumber, UInt32 inNumFrames,
                               AudioBufferList *ioData)
 {
+	UNUSED(inActionFlags);
+	UNUSED(inTimeStamp);
+	UNUSED(inBusNumber);
+
         struct state_quicktime * s = (struct state_quicktime *) inRefCon;
         int write_bytes = inNumFrames * s->audio_packet_size;
         int bytes_in_buffer = s->audio_end - s->audio_start;
diff --git a/ultragrid/src/video_display/quicktime.h b/ultragrid/src/video_display/quicktime.h
index d48d04360..c1c5762ef 100644
--- a/ultragrid/src/video_display/quicktime.h
+++ b/ultragrid/src/video_display/quicktime.h
@@ -52,8 +52,8 @@
         struct audio_frame;
 
         typedef struct {
-                unsigned char   *device;
-        unsigned char   *input;
+        char   *device;
+        char   *input;
         unsigned int    width;
         unsigned int    height;
         double          fps;