mpg123: cleaned up comments, formatting, and logging lines

also replaced mpg123decoder->handle != NULL checks with asserts

https://bugzilla.gnome.org/show_bug.cgi?id=686595

ext/mpg123/gstmpg123audiodec.c

@@ -28,8 +28,7 @@
 GST_DEBUG_CATEGORY_STATIC (mpg123_debug);
 #define GST_CAT_DEFAULT mpg123_debug
 
-/*
+/* Omitted sample formats that mpg123 supports (or at least can support):
- * Omitted sample formats that mpg123 supports (or at least can support):
  *  - 8bit integer signed
  *  - 8bit integer unsigned
  *  - a-law
@@ -46,10 +45,10 @@ GST_DEBUG_CATEGORY_STATIC (mpg123_debug);
  * no way how to find out which one of them is actually used.
  *
  * However, in all known installations, "real" equals 32bit float, so that's
- * what is used.
+ * what is used. */
- */
 
-static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+static GstStaticPadTemplate static_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS ("audio/mpeg, "
@@ -66,9 +65,9 @@ static GstFlowReturn gst_mpg123_audio_dec_push_decoded_bytes (GstMpg123AudioDec
     * mpg123_decoder, unsigned char const *decoded_bytes,
     size_t const num_decoded_bytes);
 static GstFlowReturn gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec,
-    GstBuffer * buffer);
+    GstBuffer * input_buffer);
 static gboolean gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec,
-    GstCaps * incoming_caps);
+    GstCaps * input_caps);
 static void gst_mpg123_audio_dec_flush (GstAudioDecoder * dec, gboolean hard);
 
 G_DEFINE_TYPE (GstMpg123AudioDec, gst_mpg123_audio_dec, GST_TYPE_AUDIO_DECODER);
@@ -79,7 +78,7 @@ gst_mpg123_audio_dec_class_init (GstMpg123AudioDecClass * klass)
   GObjectClass *object_class;
   GstAudioDecoderClass *base_class;
   GstElementClass *element_class;
-  GstPadTemplate *src_template;
+  GstPadTemplate *src_template, *sink_template;
   int error;
 
   GST_DEBUG_CATEGORY_INIT (mpg123_debug, "mpg123", 0, "mpg123 mp3 decoder");
@@ -96,15 +95,14 @@ gst_mpg123_audio_dec_class_init (GstMpg123AudioDecClass * klass)
       "Decodes mp3 streams using the mpg123 library",
       "Carlos Rafael Giani <dv@pseudoterminal.org>");
 
-  /*
+  /* Not using static pad template for srccaps, since the comma-separated list
-     Not using static pad template for srccaps, since the comma-separated list of formats needs to be
+   * of formats needs to be created depending on whatever mpg123 supports */
-     created depending on whatever mpg123 supports
-   */
   {
     const int *format_list;
     const long *rates_list;
     size_t num, i;
     GString *s;
+    GstCaps *src_template_caps;
 
     s = g_string_new ("audio/x-raw, ");
 
@@ -157,14 +155,16 @@ gst_mpg123_audio_dec_class_init (GstMpg123AudioDecClass * klass)
     g_string_append (s, "channels = (int) [ 1, 2 ], ");
     g_string_append (s, "layout = (string) interleaved");
 
+    src_template_caps = gst_caps_from_string (s->str);
     src_template = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
-        gst_caps_from_string (s->str));
+        src_template_caps);
 
     g_string_free (s, TRUE);
   }
 
-  gst_element_class_add_pad_template (element_class,
+  sink_template = gst_static_pad_template_get (&static_sink_template);
-      gst_static_pad_template_get (&sink_template));
+
+  gst_element_class_add_pad_template (element_class, sink_template);
   gst_element_class_add_pad_template (element_class, src_template);
 
   base_class->start = GST_DEBUG_FUNCPTR (gst_mpg123_audio_dec_start);
@@ -179,7 +179,7 @@ gst_mpg123_audio_dec_class_init (GstMpg123AudioDecClass * klass)
     GST_ERROR ("Could not initialize mpg123 library: %s",
         mpg123_plain_strerror (error));
   else
-    GST_TRACE ("mpg123 library initialized");
+    GST_INFO ("mpg123 library initialized");
 }
 
 
@@ -214,30 +214,34 @@ gst_mpg123_audio_dec_start (GstAudioDecoder * dec)
   mpg123_decoder->has_next_audioinfo = FALSE;
   mpg123_decoder->frame_offset = 0;
 
-  /*
+  /* Initially, the mpg123 handle comes with a set of default formats
-     Initially, the mpg123 handle comes with a set of default formats supported. This clears this set. 
+   * supported. This clears this set.  This is necessary, since only one
-     This is necessary, since only one format shall be supported (see set_format for more).
+   * format shall be supported (see set_format for more). */
-   */
   mpg123_format_none (mpg123_decoder->handle);
 
-  mpg123_param (mpg123_decoder->handle, MPG123_REMOVE_FLAGS, MPG123_GAPLESS, 0);        /* Built-in mpg123 support for gapless decoding is disabled for now, since it does not work well with seeking */
+  /* Built-in mpg123 support for gapless decoding is disabled for now,
-  mpg123_param (mpg123_decoder->handle, MPG123_ADD_FLAGS, MPG123_SEEKBUFFER, 0);        /* Tells mpg123 to use a small read-ahead buffer for better MPEG sync; essential for MP3 radio streams */
+   * since it does not work well with seeking */
-  mpg123_param (mpg123_decoder->handle, MPG123_RESYNC_LIMIT, -1, 0);    /* Sets the resync limit to the end of the stream (e.g. don't give up prematurely) */
+  mpg123_param (mpg123_decoder->handle, MPG123_REMOVE_FLAGS, MPG123_GAPLESS, 0);
+  /* Tells mpg123 to use a small read-ahead buffer for better MPEG sync;
+   * essential for MP3 radio streams */
+  mpg123_param (mpg123_decoder->handle, MPG123_ADD_FLAGS, MPG123_SEEKBUFFER, 0);
+  /* Sets the resync limit to the end of the stream (otherwise mpg123 may give
+   * up on decoding prematurely, especially with mp3 web radios) */
+  mpg123_param (mpg123_decoder->handle, MPG123_RESYNC_LIMIT, -1, 0);
 
   /* Open in feed mode (= encoded data is fed manually into the handle). */
   error = mpg123_open_feed (mpg123_decoder->handle);
 
   if (G_UNLIKELY (error != MPG123_OK)) {
-    GstElement *element = GST_ELEMENT (dec);
+    GST_ELEMENT_ERROR (dec, LIBRARY, INIT, (NULL),
-    GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
+        ("%s", mpg123_strerror (mpg123_decoder->handle)));
-        ("Error opening mpg123 feed: %s", mpg123_plain_strerror (error)));
     mpg123_close (mpg123_decoder->handle);
     mpg123_delete (mpg123_decoder->handle);
     mpg123_decoder->handle = NULL;
     return FALSE;
   }
 
-  GST_DEBUG_OBJECT (dec, "mpg123 decoder started");
+  GST_INFO_OBJECT (dec, "mpg123 decoder started");
 
   return TRUE;
 }
@@ -254,7 +258,7 @@ gst_mpg123_audio_dec_stop (GstAudioDecoder * dec)
     mpg123_decoder->handle = NULL;
   }
 
-  GST_DEBUG_OBJECT (dec, "mpg123 decoder stopped");
+  GST_INFO_OBJECT (dec, "mpg123 decoder stopped");
 
   return TRUE;
 }
@@ -265,39 +269,36 @@ gst_mpg123_audio_dec_push_decoded_bytes (GstMpg123AudioDec * mpg123_decoder,
     unsigned char const *decoded_bytes, size_t const num_decoded_bytes)
 {
   GstBuffer *output_buffer;
-  GstFlowReturn alloc_error;
   GstAudioDecoder *dec;
 
   output_buffer = NULL;
   dec = GST_AUDIO_DECODER (mpg123_decoder);
 
   if ((num_decoded_bytes == 0) || (decoded_bytes == NULL)) {
-    /* This occurs in the first few frames, which do not carry data; once MPG123_AUDIO_DEC_NEW_FORMAT is received, the empty frames stop occurring */
+    /* This occurs in the first few frames, which do not carry data; once
-    GST_TRACE_OBJECT (mpg123_decoder,
+     * MPG123_AUDIO_DEC_NEW_FORMAT is received, the empty frames stop occurring */
-        "Nothing was decoded -> no output buffer to push");
+    GST_DEBUG_OBJECT (mpg123_decoder,
+        "cannot decode yet, need more data -> no output buffer to push");
     return GST_FLOW_OK;
   }
 
   output_buffer = gst_buffer_new_allocate (NULL, num_decoded_bytes, NULL);
-  alloc_error = (output_buffer == NULL) ? GST_FLOW_ERROR : GST_FLOW_OK;
 
-  if (alloc_error != GST_FLOW_OK) {
+  if (output_buffer == NULL) {
-    /* This is necessary to advance playback in time, even when nothing was decoded. */
+    /* This is necessary to advance playback in time,
+     * even when nothing was decoded. */
     return gst_audio_decoder_finish_frame (dec, NULL, 1);
   } else {
     GstMapInfo info;
 
     if (gst_buffer_map (output_buffer, &info, GST_MAP_WRITE)) {
-      if (info.size != num_decoded_bytes)
-        GST_ERROR_OBJECT (mpg123_decoder,
-            "Mapped memory region has size %u instead of expected size %u",
-            info.size, num_decoded_bytes);
-      else
       memcpy (info.data, decoded_bytes, num_decoded_bytes);
-
       gst_buffer_unmap (output_buffer, &info);
-    } else
+    } else {
-      GST_ERROR_OBJECT (mpg123_decoder, "Could not map buffer");
+      GST_ERROR_OBJECT (mpg123_decoder, "gst_buffer_map() returned NULL");
+      gst_buffer_unref (output_buffer);
+      output_buffer = NULL;
+    }
 
     return gst_audio_decoder_finish_frame (dec, output_buffer, 1);
   }
@@ -305,78 +306,66 @@ gst_mpg123_audio_dec_push_decoded_bytes (GstMpg123AudioDec * mpg123_decoder,
 
 
 static GstFlowReturn
-gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec, GstBuffer * buffer)
+gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec,
+    GstBuffer * input_buffer)
 {
   GstMpg123AudioDec *mpg123_decoder;
   int decode_error;
   unsigned char *decoded_bytes;
   size_t num_decoded_bytes;
+  GstFlowReturn retval;
 
-  if (G_UNLIKELY (!buffer))
+  if (G_UNLIKELY (input_buffer == NULL))
     return GST_FLOW_OK;
 
   mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
 
-  if (G_UNLIKELY (mpg123_decoder->handle == NULL)) {
+  g_assert (mpg123_decoder->handle != NULL);
-    GstElement *element = GST_ELEMENT (dec);
-    GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
-        ("mpg123 handle is NULL"));
-    return GST_FLOW_ERROR;
-  }
 
   /* The actual decoding */
   {
-    unsigned char const *inmemory;
-    size_t inmemsize;
-    GstMemory *memory;
     GstMapInfo info;
 
-    memory = gst_buffer_get_all_memory (buffer);
+    /* feed input data */
-    if (memory == NULL)
+    if (gst_buffer_map (input_buffer, &info, GST_MAP_READ)) {
-      return GST_FLOW_ERROR;
+      mpg123_feed (mpg123_decoder->handle, info.data, info.size);
-
+      gst_buffer_unmap (input_buffer, &info);
-    if (!gst_memory_map (memory, &info, GST_MAP_READ)) {
+    } else {
-      gst_memory_unref (memory);
+      GST_ERROR_OBJECT (mpg123_decoder, "gst_memory_map() failed");
       return GST_FLOW_ERROR;
     }
 
-    inmemory = info.data;
+    /* Try to decode a frame */
-    inmemsize = info.size;
-
-    mpg123_feed (mpg123_decoder->handle, inmemory, inmemsize);
     decoded_bytes = NULL;
     num_decoded_bytes = 0;
     decode_error = mpg123_decode_frame (mpg123_decoder->handle,
         &mpg123_decoder->frame_offset, &decoded_bytes, &num_decoded_bytes);
-
-    gst_memory_unmap (memory, &info);
-    gst_memory_unref (memory);
   }
 
+  retval = GST_FLOW_OK;
+
   switch (decode_error) {
     case MPG123_NEW_FORMAT:
-      /*
+      /* As mentioned in gst_mpg123_audio_dec_set_format(), the next audioinfo
-         As mentioned in gst_mpg123_audio_dec_set_format(), the next audioinfo is not set immediately;
+       * is not set immediately; instead, the code waits for mpg123 to take
-         instead, the code waits for mpg123 to take note of the new format, and then sets the audioinfo
+       * note of the new format, and then sets the audioinfo. This fixes glitches
-         This fixes glitches with mp3s containing several format headers (for example, first half using 44.1kHz, second half 32 kHz)
+       * with mp3s containing several format headers (for example, first half
-       */
+       * using 44.1kHz, second half 32 kHz) */
 
-      GST_DEBUG_OBJECT (dec,
+      GST_LOG_OBJECT (dec,
           "mpg123 reported a new format -> setting next srccaps");
 
       gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
           num_decoded_bytes);
 
-      /*
+      /* If there is a next audioinfo, use it, then set has_next_audioinfo to
-         If there is a next audioinfo, use it, then set has_next_audioinfo to FALSE, to make sure
+       * FALSE, to make sure gst_audio_decoder_set_output_format() isn't called
-         gst_audio_decoder_set_output_format() isn't called again until set_format is called by the base class
+       * again until set_format is called by the base class */
-       */
       if (mpg123_decoder->has_next_audioinfo) {
         if (!gst_audio_decoder_set_output_format (dec,
                 &(mpg123_decoder->next_audioinfo))) {
-          GstElement *element = GST_ELEMENT (dec);
+          GST_WARNING_OBJECT (dec, "Unable to set output format");
-          GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
+          retval = GST_FLOW_NOT_NEGOTIATED;
-              ("Unable to set output format"));
         }
         mpg123_decoder->has_next_audioinfo = FALSE;
       }
@@ -385,60 +374,90 @@ gst_mpg123_audio_dec_handle_frame (GstAudioDecoder * dec, GstBuffer * buffer)
 
     case MPG123_NEED_MORE:
     case MPG123_OK:
-      return gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder,
+      retval = gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder,
           decoded_bytes, num_decoded_bytes);
+      break;
 
-      /* If this happens, then the upstream parser somehow missed the ending of the bitstream */
     case MPG123_DONE:
-      GST_DEBUG_OBJECT (dec, "mpg123 is done decoding");
+      /* If this happens, then the upstream parser somehow missed the ending
+       * of the bitstream */
+      GST_LOG_OBJECT (dec, "mpg123 is done decoding");
       gst_mpg123_audio_dec_push_decoded_bytes (mpg123_decoder, decoded_bytes,
           num_decoded_bytes);
-      return GST_FLOW_EOS;
+      retval = GST_FLOW_EOS;
+      break;
 
-      /* Anything else is considered an error */
     default:
     {
-      GstElement *element = GST_ELEMENT (dec);
+      /* Anything else is considered an error */
-      GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL), ("Decoding error: %s",
+      int errcode;
-              mpg123_plain_strerror (decode_error)));
+      switch (decode_error) {
-
+        case MPG123_ERR:
-      return GST_FLOW_ERROR;
+          errcode = mpg123_errcode (mpg123_decoder->handle);
+          break;
+        default:
+          errcode = decode_error;
+      }
+      switch (errcode) {
+        case MPG123_BAD_OUTFORMAT:{
+          GstCaps *input_caps =
+              gst_pad_get_current_caps (GST_AUDIO_DECODER_SINK_PAD (dec));
+          GST_ELEMENT_ERROR (dec, STREAM, FORMAT, (NULL),
+              ("Output sample format could not be used when trying to decode frame. "
+                  "This is typically caused when the input caps (often the sample "
+                  "rate) do not match the actual format of the audio data. "
+                  "Input caps: %" GST_PTR_FORMAT, input_caps)
+              );
+          gst_caps_unref (input_caps);
+          break;
+        }
+        default:{
+          char const *errmsg = mpg123_plain_strerror (errcode);
+          GST_ERROR_OBJECT (dec, "Reported error: %s", errmsg);
         }
       }
 
-  return GST_FLOW_OK;
+      retval = GST_FLOW_ERROR;
+    }
+  }
+
+  return retval;
 }
 
 
 static gboolean
-gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * incoming_caps)
+gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * input_caps)
 {
-/*
+/* Using the parsed information upstream, and the list of allowed caps
-	Using the parsed information upstream, and the list of allowed caps downstream, this code
+ * downstream, this code tries to find a suitable audio info. It is important
-	tries to find a suitable audio info. It is important to keep in mind that the rate and number of channels
+ * to keep in mind that the rate and number of channels should never deviate
-	should never deviate from the one the bitstream has, otherwise mpg123 has to mix channels and/or
+ * from the one the bitstream has, otherwise mpg123 has to mix channels and/or
-	resample (and as its docs say, its internal resampler is very crude). The sample format, however,
+ * resample (and as its docs say, its internal resampler is very crude). The
-	can be chosen freely, because the MPEG specs do not mandate any special format.
+ * sample format, however, can be chosen freely, because the MPEG specs do not
-	Therefore, rate and number of channels are taken from upstream (which parsed the MPEG frames, so
+ * mandate any special format. Therefore, rate and number of channels are taken
-	the incoming_caps contain exactly the rate and number of channels the bitstream actually has), while
+ * from upstream (which parsed the MPEG frames, so the input_caps contain
-	the sample format is chosen by trying out all caps that are allowed by downstream. This way, the output
+ * exactly the rate and number of channels the bitstream actually has), while
-	is adjusted to what the downstream prefers.
+ * the sample format is chosen by trying out all caps that are allowed by
-
+ * downstream. This way, the output is adjusted to what the downstream prefers.
-	Also, the new output audio info is not set immediately. Instead, it is considered the "next audioinfo".
+ *
-	The code waits for mpg123 to notice the new format (= when mpg123_decode_frame() returns MPG123_AUDIO_DEC_NEW_FORMAT),
+ * Also, the new output audio info is not set immediately. Instead, it is
-	and then sets the next audioinfo. Otherwise, the next audioinfo is set too soon, which may cause problems with
+ * considered the "next audioinfo". The code waits for mpg123 to notice the new
-	mp3s containing several format headers. One example would be an mp3 with the first 30 seconds using 44.1 kHz,
+ * format (= when mpg123_decode_frame() returns MPG123_AUDIO_DEC_NEW_FORMAT),
-	then the next 30 seconds using 32 kHz. Rare, but possible.
+ * and then sets the next audioinfo. Otherwise, the next audioinfo is set too
-
+ * soon, which may cause problems with mp3s containing several format headers.
-	STEPS:
+ * One example would be an mp3 with the first 30 seconds using 44.1 kHz, then
-
+ * the next 30 seconds using 32 kHz. Rare, but possible.
-	1. get rate and channels from incoming_caps
+ *
-	2. get allowed caps from src pad
+ * STEPS:
-	3. for each structure in allowed caps:
+ *
-	3.1. take format
+ * 1. get rate and channels from input_caps
-	3.2. if the combination of format with rate and channels is unsupported by mpg123, go to (3),
+ * 2. get allowed caps from src pad
-	     or exit with error if there are no more structures to try
+ * 3. for each structure in allowed caps:
-	3.3. create next audioinfo out of rate,channels,format, and exit
+ * 3.1. take format
+ * 3.2. if the combination of format with rate and channels is unsupported by
+ *      mpg123, go to (3), or exit with error if there are no more structures
+ *      to try
+ * 3.3. create next audioinfo out of rate,channels,format, and exit
  */
 
 
@@ -450,30 +469,26 @@ gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * incoming_caps)
 
   mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
 
-  if (G_UNLIKELY (mpg123_decoder->handle == NULL)) {
+  g_assert (mpg123_decoder->handle != NULL);
-    GstElement *element = GST_ELEMENT (dec);
-    GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
-        ("mpg123 handle is NULL"));
-    return FALSE;
-  }
 
   mpg123_decoder->has_next_audioinfo = FALSE;
 
-  /* Get rate and channels from incoming_caps */
+  /* Get rate and channels from input_caps */
   {
     GstStructure *structure;
     gboolean err = FALSE;
 
-    /* Only the first structure is used (multiple incoming structures don't make sense */
+    /* Only the first structure is used (multiple
-    structure = gst_caps_get_structure (incoming_caps, 0);
+     * input caps structures don't make sense */
+    structure = gst_caps_get_structure (input_caps, 0);
 
     if (!gst_structure_get_int (structure, "rate", &rate)) {
       err = TRUE;
-      GST_ERROR_OBJECT (dec, "Incoming caps do not have a rate value");
+      GST_ERROR_OBJECT (dec, "Input caps do not have a rate value");
     }
     if (!gst_structure_get_int (structure, "channels", &channels)) {
       err = TRUE;
-      GST_ERROR_OBJECT (dec, "Incoming caps do not have a channel value");
+      GST_ERROR_OBJECT (dec, "Input caps do not have a channel value");
     }
 
     if (err)
@@ -485,8 +500,6 @@ gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * incoming_caps)
     GstCaps *allowed_srccaps_unnorm =
         gst_pad_get_allowed_caps (GST_AUDIO_DECODER_SRC_PAD (dec));
     allowed_srccaps = gst_caps_normalize (allowed_srccaps_unnorm);
-    /* TODO: this causes errors with 1.0 - perhaps a bug? */
-    /*gst_caps_unref(allowed_srccaps_unnorm); */
   }
 
   /* Go through all allowed caps, pick the first one that matches */
@@ -549,7 +562,7 @@ gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * incoming_caps)
         GST_DEBUG_OBJECT (dec,
             "mpg123 cannot use caps %" GST_PTR_FORMAT
             " because mpg123_format() failed: %s", structure,
-            mpg123_plain_strerror (err));
+            mpg123_strerror (mpg123_decoder->handle));
         continue;
       }
     }
@@ -557,7 +570,7 @@ gst_mpg123_audio_dec_set_format (GstAudioDecoder * dec, GstCaps * incoming_caps)
     gst_audio_info_init (&(mpg123_decoder->next_audioinfo));
     gst_audio_info_set_format (&(mpg123_decoder->next_audioinfo), format, rate,
         channels, NULL);
-    GST_DEBUG_OBJECT (dec, "The next audio format is: %s, %u Hz, %u channels",
+    GST_LOG_OBJECT (dec, "The next audio format is: %s, %u Hz, %u channels",
         format_str, rate, channels);
     mpg123_decoder->has_next_audioinfo = TRUE;
 
@@ -580,25 +593,20 @@ gst_mpg123_audio_dec_flush (GstAudioDecoder * dec, gboolean hard)
 
   hard = hard;
 
-  GST_DEBUG_OBJECT (dec, "Flushing decoder");
+  GST_LOG_OBJECT (dec, "Flushing decoder");
 
   mpg123_decoder = GST_MPG123_AUDIO_DEC (dec);
 
-  if (G_UNLIKELY (mpg123_decoder->handle == NULL)) {
+  g_assert (mpg123_decoder->handle != NULL);
-    GstElement *element = GST_ELEMENT (dec);
-    GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
-        ("mpg123 handle is NULL"));
-    return;
-  }
 
   /* Flush by reopening the feed */
   mpg123_close (mpg123_decoder->handle);
   error = mpg123_open_feed (mpg123_decoder->handle);
 
   if (G_UNLIKELY (error != MPG123_OK)) {
-    GstElement *element = GST_ELEMENT (dec);
+    GST_ELEMENT_ERROR (dec, LIBRARY, INIT, (NULL),
-    GST_ELEMENT_ERROR (element, STREAM, DECODE, (NULL),
+        ("Error while reopening mpg123 feed: %s",
-        ("Error reopening mpg123 feed: %s", mpg123_plain_strerror (error)));
+            mpg123_plain_strerror (error)));
     mpg123_close (mpg123_decoder->handle);
     mpg123_delete (mpg123_decoder->handle);
     mpg123_decoder->handle = NULL;
@@ -606,10 +614,10 @@ gst_mpg123_audio_dec_flush (GstAudioDecoder * dec, gboolean hard)
 
   mpg123_decoder->has_next_audioinfo = FALSE;
 
-  /*
+  /* opening/closing feeds do not affect the format defined by the
-     opening/closing feeds do not affect the format defined by the mpg123_format() call that was made in gst_mpg123_audio_dec_set_format(),
+   * mpg123_format() call that was made in gst_mpg123_audio_dec_set_format(),
-     and since the up/downstream caps are not expected to change here, no mpg123_format() calls are done
+   * and since the up/downstream caps are not expected to change here, no
-   */
+   * mpg123_format() calls are done */
 }
 
 static gboolean