diff --git a/formats/format_g719.c b/formats/format_g719.c
index aace0edc73..903fbcde98 100644
--- a/formats/format_g719.c
+++ b/formats/format_g719.c
@@ -82,11 +82,20 @@ static int g719seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 	sample_offset = SAMPLES_TO_BYTES(sample_offset);
 
-	cur = ftello(fs->f);
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	fseeko(fs->f, 0, SEEK_END);
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	max = ftello(fs->f);
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
 	if (whence == SEEK_SET)
 		offset = sample_offset;
@@ -106,7 +115,18 @@ static int g719seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int g719trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	return ftruncate(fd, cur);
 }
 
 static off_t g719tell(struct ast_filestream *fs)
diff --git a/formats/format_g723.c b/formats/format_g723.c
index 7eba741475..b3e87367e3 100644
--- a/formats/format_g723.c
+++ b/formats/format_g723.c
@@ -118,10 +118,19 @@ static int g723_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int g723_trunc(struct ast_filestream *fs)
 {
-	/* Truncate file to current length */
-	if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for g723 filestream %p: %s\n", fs, strerror(errno));
 		return -1;
-	return 0;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g723 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t g723_tell(struct ast_filestream *fs)
diff --git a/formats/format_g729.c b/formats/format_g729.c
index 042977728c..477883f179 100644
--- a/formats/format_g729.c
+++ b/formats/format_g729.c
@@ -113,10 +113,19 @@ static int g729_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int g729_trunc(struct ast_filestream *fs)
 {
-	/* Truncate file to current length */
-	if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for g729 filestream %p: %s\n", fs, strerror(errno));
 		return -1;
-	return 0;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g729 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t g729_tell(struct ast_filestream *fs)
diff --git a/formats/format_gsm.c b/formats/format_gsm.c
index 03419c2f61..4cf6579a60 100644
--- a/formats/format_gsm.c
+++ b/formats/format_gsm.c
@@ -108,20 +108,33 @@ static int gsm_write(struct ast_filestream *fs, struct ast_frame *f)
 
 static int gsm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-	off_t offset=0,min,cur,max,distance;
-	
-	min = 0;
-	cur = ftello(fs->f);
-	fseeko(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);
+	off_t offset = 0, min = 0, cur, max, distance;
+
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
 	/* have to fudge to frame here, so not fully to sample */
-	distance = (sample_offset/GSM_SAMPLES) * GSM_FRAME_SIZE;
-	if(whence == SEEK_SET)
+	distance = (sample_offset / GSM_SAMPLES) * GSM_FRAME_SIZE;
+	if (whence == SEEK_SET) {
 		offset = distance;
-	else if(whence == SEEK_CUR || whence == SEEK_FORCECUR)
+	} else if (whence == SEEK_CUR || whence == SEEK_FORCECUR) {
 		offset = distance + cur;
-	else if(whence == SEEK_END)
+	} else if (whence == SEEK_END) {
 		offset = max - distance;
+	}
+
 	/* Always protect against seeking past the begining. */
 	offset = (offset < min)?min:offset;
 	if (whence != SEEK_FORCECUR) {
@@ -140,13 +153,31 @@ static int gsm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int gsm_trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for gsm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in gsm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t gsm_tell(struct ast_filestream *fs)
 {
 	off_t offset = ftello(fs->f);
-	return (offset/GSM_FRAME_SIZE)*GSM_SAMPLES;
+
+	if (offset < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine offset for gsm filestream %p: %s\n", fs, strerror(errno));
+		return 0;
+	}
+
+	return (offset / GSM_FRAME_SIZE) * GSM_SAMPLES;
 }
 
 static struct ast_format_def gsm_f = {
diff --git a/formats/format_h263.c b/formats/format_h263.c
index b00ae0fb30..ec08867d8b 100644
--- a/formats/format_h263.c
+++ b/formats/format_h263.c
@@ -146,10 +146,19 @@ static int h263_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int h263_trunc(struct ast_filestream *fs)
 {
-	/* Truncate file to current length */
-	if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for h263 filestream %p: %s\n", fs, strerror(errno));
 		return -1;
-	return 0;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in h263 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t h263_tell(struct ast_filestream *fs)
diff --git a/formats/format_h264.c b/formats/format_h264.c
index 155f469759..25ba54a77c 100644
--- a/formats/format_h264.c
+++ b/formats/format_h264.c
@@ -140,10 +140,19 @@ static int h264_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int h264_trunc(struct ast_filestream *fs)
 {
-	/* Truncate file to current length */
-	if (ftruncate(fileno(fs->f), ftell(fs->f)) < 0)
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for h264 filestream %p: %s\n", fs, strerror(errno));
 		return -1;
-	return 0;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in h264 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t h264_tell(struct ast_filestream *fs)
diff --git a/formats/format_ilbc.c b/formats/format_ilbc.c
index 7a08ca515c..e18c78ab1b 100644
--- a/formats/format_ilbc.c
+++ b/formats/format_ilbc.c
@@ -111,10 +111,19 @@ static int ilbc_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int ilbc_trunc(struct ast_filestream *fs)
 {
-	/* Truncate file to current length */
-	if (ftruncate(fileno(fs->f), ftello(fs->f)) < 0)
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for iLBC filestream %p: %s\n", fs, strerror(errno));
 		return -1;
-	return 0;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in iLBC filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t ilbc_tell(struct ast_filestream *fs)
diff --git a/formats/format_pcm.c b/formats/format_pcm.c
index 3bf27388c6..2a740ef5d0 100644
--- a/formats/format_pcm.c
+++ b/formats/format_pcm.c
@@ -105,9 +105,20 @@ static int pcm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 	off_t cur, max, offset = 0;
  	int ret = -1;	/* assume error */
 
-	cur = ftello(fs->f);
-	fseeko(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in pcm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of pcm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in pcm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
 	switch (whence) {
 	case SEEK_SET:
@@ -151,7 +162,18 @@ static int pcm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int pcm_trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int cur, fd;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for pcm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in pcm filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t pcm_tell(struct ast_filestream *fs)
@@ -374,7 +396,7 @@ static int au_rewrite(struct ast_filestream *s, const char *comment)
 /* XXX check this, probably incorrect */
 static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-	off_t min, max, cur;
+	off_t min = AU_HEADER_SIZE, max, cur;
 	long offset = 0, bytes;
 
 	if (fs->fmt->format.id == AST_FORMAT_G722)
@@ -382,10 +404,20 @@ static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 	else
 		bytes = sample_offset;
 
-	min = AU_HEADER_SIZE;
-	cur = ftello(fs->f);
-	fseek(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in au filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of au filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in au filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
 	if (whence == SEEK_SET)
 		offset = bytes + min;
@@ -406,8 +438,21 @@ static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int au_trunc(struct ast_filestream *fs)
 {
-	if (ftruncate(fileno(fs->f), ftell(fs->f)))
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for au filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in au filestream %p: %s\n", fs, strerror(errno));
 		return -1;
+	}
+	/* Truncate file to current length */
+	if (ftruncate(fd, cur)) {
+		return -1;
+	}
 	return update_header(fs->f);
 }
 
diff --git a/formats/format_siren14.c b/formats/format_siren14.c
index 1ce50fad4b..08c2cbfbf7 100644
--- a/formats/format_siren14.c
+++ b/formats/format_siren14.c
@@ -82,11 +82,20 @@ static int siren14seek(struct ast_filestream *fs, off_t sample_offset, int whenc
 
 	sample_offset = SAMPLES_TO_BYTES(sample_offset);
 
-	cur = ftello(fs->f);
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in siren14 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	fseeko(fs->f, 0, SEEK_END);
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of siren14 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	max = ftello(fs->f);
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in siren14 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
 	if (whence == SEEK_SET)
 		offset = sample_offset;
@@ -106,7 +115,19 @@ static int siren14seek(struct ast_filestream *fs, off_t sample_offset, int whenc
 
 static int siren14trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for siren14 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in siren14 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t siren14tell(struct ast_filestream *fs)
diff --git a/formats/format_siren7.c b/formats/format_siren7.c
index 2e5182d3c6..955323ed26 100644
--- a/formats/format_siren7.c
+++ b/formats/format_siren7.c
@@ -82,11 +82,20 @@ static int siren7seek(struct ast_filestream *fs, off_t sample_offset, int whence
 
 	sample_offset = SAMPLES_TO_BYTES(sample_offset);
 
-	cur = ftello(fs->f);
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in siren7 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	fseeko(fs->f, 0, SEEK_END);
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of siren7 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
-	max = ftello(fs->f);
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in siren7 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
 
 	if (whence == SEEK_SET)
 		offset = sample_offset;
@@ -106,7 +115,19 @@ static int siren7seek(struct ast_filestream *fs, off_t sample_offset, int whence
 
 static int siren7trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for siren7 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in siren7 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t siren7tell(struct ast_filestream *fs)
diff --git a/formats/format_sln.c b/formats/format_sln.c
index 1a73cdfbbf..b90f6b27a2 100644
--- a/formats/format_sln.c
+++ b/formats/format_sln.c
@@ -72,13 +72,25 @@ static int generic_write(struct ast_filestream *fs, struct ast_frame *f, enum as
 
 static int slinear_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-	off_t offset=0,min,cur,max;
+	off_t offset=0, min = 0, cur, max;
 
-	min = 0;
 	sample_offset <<= 1;
-	cur = ftello(fs->f);
-	fseeko(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);
+
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of sln filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in sln filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
 	if (whence == SEEK_SET)
 		offset = sample_offset;
 	else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
@@ -95,7 +107,19 @@ static int slinear_seek(struct ast_filestream *fs, off_t sample_offset, int when
 
 static int slinear_trunc(struct ast_filestream *fs)
 {
-	return ftruncate(fileno(fs->f), ftello(fs->f));
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for sln filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);
 }
 
 static off_t slinear_tell(struct ast_filestream *fs)
diff --git a/formats/format_vox.c b/formats/format_vox.c
index 7d34df99cb..bfa0d8e4ca 100644
--- a/formats/format_vox.c
+++ b/formats/format_vox.c
@@ -78,32 +78,54 @@ static int vox_write(struct ast_filestream *s, struct ast_frame *f)
 
 static int vox_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-     off_t offset=0,min,cur,max,distance;
-	
-     min = 0;
-     cur = ftello(fs->f);
-     fseeko(fs->f, 0, SEEK_END);
-	 max = ftello(fs->f);
-	 
-     /* have to fudge to frame here, so not fully to sample */
-     distance = sample_offset/2;
-     if(whence == SEEK_SET)
-	  offset = distance;
-     else if(whence == SEEK_CUR || whence == SEEK_FORCECUR)
-	  offset = distance + cur;
-     else if(whence == SEEK_END)
-	  offset = max - distance;
-     if (whence != SEEK_FORCECUR) {
-	  offset = (offset > max)?max:offset;
-	  offset = (offset < min)?min:offset;
-     }
-     return fseeko(fs->f, offset, SEEK_SET);
+	off_t offset = 0, min = 0, cur, max, distance;
+
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in g719 filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	/* have to fudge to frame here, so not fully to sample */
+	distance = sample_offset/2;
+	if (whence == SEEK_SET) {
+		offset = distance;
+	} else if (whence == SEEK_CUR || whence == SEEK_FORCECUR) {
+		offset = distance + cur;
+	} else if (whence == SEEK_END) {
+		offset = max - distance;
+	}
+	if (whence != SEEK_FORCECUR) {
+		offset = (offset > max)?max:offset;
+		offset = (offset < min)?min:offset;
+	}
+	return fseeko(fs->f, offset, SEEK_SET);
 }
 
 static int vox_trunc(struct ast_filestream *fs)
 {
-     return ftruncate(fileno(fs->f), ftello(fs->f));
-}
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for vox filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in vox filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	return ftruncate(fd, cur);}
 
 static off_t vox_tell(struct ast_filestream *fs)
 {
diff --git a/formats/format_wav.c b/formats/format_wav.c
index 78b3a7fa11..df09db353a 100644
--- a/formats/format_wav.c
+++ b/formats/format_wav.c
@@ -42,6 +42,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #define	WAV_BUF_SIZE	320
 
+#define WAV_HEADER_SIZE 44
+
 struct wav_desc {	/* format-specific parameters */
 	int hz;
 	int bytes;
@@ -452,13 +454,25 @@ static int wav_write(struct ast_filestream *fs, struct ast_frame *f)
 
 static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-	off_t min, max, cur, offset = 0, samples;
+	off_t min = WAV_HEADER_SIZE, max, cur, offset = 0, samples;
 
 	samples = sample_offset * 2; /* SLINEAR is 16 bits mono, so sample_offset * 2 = bytes */
-	min = 44; /* wav header is 44 bytes */
-	cur = ftello(fs->f);
-	fseeko(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);
+
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in wav filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of wav filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in wav filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
 	if (whence == SEEK_SET)
 		offset = samples + min;
 	else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
@@ -475,8 +489,21 @@ static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int wav_trunc(struct ast_filestream *fs)
 {
-	if (ftruncate(fileno(fs->f), ftello(fs->f)))
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for wav filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in wav filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	/* Truncate file to current length */
+	if (ftruncate(fd, cur)) {
 		return -1;
+	}
 	return update_header(fs->f);
 }
 
diff --git a/formats/format_wav_gsm.c b/formats/format_wav_gsm.c
index 35d4339f96..bbf3339bc0 100644
--- a/formats/format_wav_gsm.c
+++ b/formats/format_wav_gsm.c
@@ -475,13 +475,25 @@ static int wav_write(struct ast_filestream *s, struct ast_frame *f)
 
 static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 {
-	off_t offset=0, distance, max;
+	off_t offset = 0, min = MSGSM_DATA_OFFSET, distance, max, cur;
 	struct wavg_desc *s = (struct wavg_desc *)fs->_private;
 
-	off_t min = MSGSM_DATA_OFFSET;
-	off_t cur = ftello(fs->f);
-	fseek(fs->f, 0, SEEK_END);
-	max = ftello(fs->f);	/* XXX ideally, should round correctly */
+	if ((cur = ftello(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in WAV filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	if (fseeko(fs->f, 0, SEEK_END) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to seek to end of WAV filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
+	/* XXX ideally, should round correctly */
+	if ((max = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine max position in WAV filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+
 	/* Compute the distance in bytes, rounded to the block size */
 	distance = (sample_offset/MSGSM_SAMPLES) * MSGSM_FRAME_SIZE;
 	if (whence == SEEK_SET)
@@ -511,8 +523,21 @@ static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 
 static int wav_trunc(struct ast_filestream *fs)
 {
-	if (ftruncate(fileno(fs->f), ftello(fs->f)))
+	int fd;
+	off_t cur;
+
+	if ((fd = fileno(fs->f)) < 0) {
+		ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for WAV filestream %p: %s\n", fs, strerror(errno));
+		return -1;
+	}
+	if ((cur = ftello(fs->f) < 0)) {
+		ast_log(AST_LOG_WARNING, "Unable to determine current position in WAV filestream %p: %s\n", fs, strerror(errno));
 		return -1;
+	}
+	/* Truncate file to current length */
+	if (ftruncate(fd, cur)) {
+		return -1;
+	}
 	return update_header(fs->f);
 }