diff --git a/po/POTFILES.in b/po/POTFILES.in
index 0b642a9..c63a6c6 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -1,3 +1,7 @@
 [encoding: UTF-8]
 data/spek.desktop.in.in
 src/spek.vala
+src/spek-audio.c
+src/spek-pipeline.vala
+src/spek-spectrogram.vala
+src/spek-window.vala
diff --git a/po/POTFILES.skip b/po/POTFILES.skip
index 5667bbd..4419fb0 100644
--- a/po/POTFILES.skip
+++ b/po/POTFILES.skip
@@ -1,4 +1,5 @@
 data/spek.desktop.in
 src/spek.c
+src/spek-pipeline.c
 src/spek-spectrogram.c
 src/spek-window.c
diff --git a/src/spek-audio.c b/src/spek-audio.c
index 2c9856d..87eca09 100644
--- a/src/spek-audio.c
+++ b/src/spek-audio.c
@@ -16,6 +16,8 @@
  * along with Spek.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <glib/gi18n.h>
+
 #include "spek-audio.h"
 
 void spek_audio_init () {
@@ -31,16 +33,15 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
 	cx->file_name = g_strdup (file_name);
 
 	if (av_open_input_file (&cx->format_context, file_name, NULL, 0, NULL) != 0) {
-		/* TODO
-		 */
-		printf ("cannot open\n");
+		cx->error = _("Cannot open input file");
 		return cx;
 	}
 	if (av_find_stream_info (cx->format_context) < 0) {
-		/* TODO
-		 */
-		printf ("cannot find stream info\n");
-		return cx;
+		/* 24-bit APE returns an error but parses the stream info just fine */
+		if (cx->format_context->nb_streams <= 0) {
+			cx->error = _("Cannot find stream info");
+			return cx;
+		}
 	}
 	cx->audio_stream = -1;
 	for (i = 0; i < cx->format_context->nb_streams; i++) {
@@ -50,25 +51,16 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
 		}
 	}
 	if (cx->audio_stream == -1) {
-		/* TODO
-		 */
-		printf ("no audio streams\n");
+		cx->error = _("The file contains no audio streams");
 		return cx;
 	}
 	cx->codec_context = cx->format_context->streams[cx->audio_stream]->codec;
 	cx->codec = avcodec_find_decoder (cx->codec_context->codec_id);
 	if (cx->codec == NULL) {
-		/* TODO
-		 */
-		printf ("cannot find decoder\n");
-		return cx;
-	}
-	if (avcodec_open (cx->codec_context, cx->codec) < 0) {
-		/* TODO
-		 */
-		printf ("cannot open decoder\n");
+		cx->error = _("Cannot find decoder");
 		return cx;
 	}
+	/* We can already fill in the stream info even if the codec won't be able to open it */
 	cx->codec_name = g_strdup (cx->codec->long_name);
 	cx->bit_rate = cx->codec_context->bit_rate;
 	cx->sample_rate = cx->codec_context->sample_rate;
@@ -78,6 +70,10 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
 		cx->bits_per_sample = cx->codec_context->bits_per_coded_sample;
 	}
 	cx->channels = cx->codec_context->channels;
+	if (avcodec_open (cx->codec_context, cx->codec) < 0) {
+		cx->error = _("Cannot open decoder");
+		return cx;
+	}
 	return cx;
 }
 
diff --git a/src/spek-audio.h b/src/spek-audio.h
index 16336bb..87ca376 100644
--- a/src/spek-audio.h
+++ b/src/spek-audio.h
@@ -33,6 +33,7 @@ typedef struct {
 	 */
 	gchar *file_name;
 	gchar *codec_name;
+	gchar *error;
 	gint bit_rate;
 	gint sample_rate;
 	gint bits_per_sample;
diff --git a/src/spek-pipeline.vala b/src/spek-pipeline.vala
index ca45383..24474d3 100644
--- a/src/spek-pipeline.vala
+++ b/src/spek-pipeline.vala
@@ -22,7 +22,6 @@ namespace Spek {
 		public string description { get; private set; }
 
 		public Pipeline (string file_name) {
-			// TODO: check for errors
 			cx = new Audio.Context (file_name);
 
 			// Build the description string.
@@ -46,6 +45,11 @@ namespace Spek {
 					printf (cx.channels);
 			}
 			description = items.length > 0 ? string.joinv (", ", items) : "";
+
+			if (cx.error != null) {
+				// TRANSLATORS: first %s is the error message, second %s is stream description.
+				description = _("%s: %s").printf (cx.error, description);
+			}
 		}
 
 		public string file_name {
diff --git a/vapi/spek-audio.vapi b/vapi/spek-audio.vapi
index c8eb74b..0de813a 100644
--- a/vapi/spek-audio.vapi
+++ b/vapi/spek-audio.vapi
@@ -5,6 +5,7 @@ namespace Spek.Audio {
 	public class Context {
 		public string file_name;
 		public string codec_name;
+		public string error;
 		public int bit_rate;
 		public int sample_rate;
 		public int bits_per_sample;