Build the audio description string using ffmpeg

src/spek-audio.c

@@ -19,6 +19,7 @@
 #include "spek-audio.h"
 
 void spek_audio_init () {
+	avcodec_init ();
 	av_register_all ();
 }
 
@@ -32,11 +33,13 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
 	if (av_open_input_file (&cx->format_context, file_name, NULL, 0, NULL) != 0) {
 		/* TODO
 		 */
+		printf ("cannot open\n");
 		return cx;
 	}
-	if (av_find_stream_info (cx->format_context)) {
+	if (av_find_stream_info (cx->format_context) < 0) {
 		/* TODO
 		 */
+		printf ("cannot find stream info\n");
 		return cx;
 	}
 	cx->audio_stream = -1;
@@ -49,24 +52,32 @@ SpekAudioContext * spek_audio_open (const char *file_name) {
 	if (cx->audio_stream == -1) {
 		/* TODO
 		 */
+		printf ("no audio streams\n");
 		return cx;
 	}
 	cx->codec_context = cx->format_context->streams[cx->audio_stream]->codec;
-	cx->bit_rate = cx->codec_context->bit_rate;
-	cx->sample_rate = cx->codec_context->sample_rate;
-	cx->channels = cx->codec_context->channels;
 	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");
 		return cx;
 	}
-
+	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;
+	cx->bits_per_sample = cx->codec_context->bits_per_raw_sample;
+	if (!cx->bits_per_sample) {
+		/* APE uses bpcs, FLAC uses bprs. */
+		cx->bits_per_sample = cx->codec_context->bits_per_coded_sample;
+	}
+	cx->channels = cx->codec_context->channels;
 	return cx;
 }
 
@@ -74,6 +85,9 @@ void spek_audio_close (SpekAudioContext *cx) {
 	if (cx->file_name != NULL) {
 		g_free (cx->file_name);
 	}
+	if (cx->codec_name != NULL) {
+		g_free (cx->codec_name);
+	}
 	if (cx->codec_context != NULL) {
 		avcodec_close (cx->codec_context);
 	}

src/spek-audio.h

@@ -32,8 +32,10 @@ typedef struct {
 	/* Exposed properties
 	 */
 	gchar *file_name;
+	gchar *codec_name;
 	gint bit_rate;
 	gint sample_rate;
+	gint bits_per_sample;
 	gint channels;
 } SpekAudioContext;
 

src/spek-pipeline.vala

@@ -19,10 +19,33 @@
 namespace Spek {
 	public class Pipeline {
 		private Audio.Context cx;
+		public string description { get; private set; }
 
 		public Pipeline (string file_name) {
-			cx = new Audio.Context (file_name);
 			// TODO: check for errors
+			cx = new Audio.Context (file_name);
+
+			// Build the description string.
+			string[] items = {};
+			if (cx.codec_name != null) {
+				items += cx.codec_name;
+			}
+			if (cx.bit_rate != 0) {
+				items += _("%d kbps").printf (cx.bit_rate / 1000);
+			}
+			if (cx.sample_rate != 0) {
+				items += _("%d Hz").printf (cx.sample_rate);
+			}
+			// Show bits per sample only if there is no bitrate.
+			if (cx.bits_per_sample != 0 && cx.bit_rate == 0) {
+				items += ngettext (
+					"%d bit", "%d bits", cx.bits_per_sample).printf (cx.bits_per_sample);
+			}
+			if (cx.channels != 0) {
+				items += ngettext ("%d channel", "%d channels", cx.channels).
+					printf (cx.channels);
+			}
+			description = items.length > 0 ? string.joinv (", ", items) : "";
 		}
 
 		public string file_name {

src/spek-spectrogram.vala

@@ -65,7 +65,7 @@ namespace Spek {
 
 			// TODO
 			var pipeline = new Pipeline (file_name);
-			print ("%s:\nbr=%i sr=%i ch=%i\n\n", pipeline.file_name, pipeline.bit_rate, pipeline.sample_rate, pipeline.channels);
+			print ("%s:\n%s\n", file_name, pipeline.description);
 
 			start ();
 		}

vapi/spek-audio.vapi

@@ -4,8 +4,10 @@ namespace Spek.Audio {
 	[CCode (free_function = "spek_audio_close")]
 	public class Context {
 		public string file_name;
+		public string codec_name;
 		public int bit_rate;
 		public int sample_rate;
+		public int bits_per_sample;
 		public int channels;
 
 		[CCode (cname = "spek_audio_open")]