gst/mpegaudioparse/gstmpegaudioparse.*: Add initial support for reading VBRI headers as found in VBR files created by...

Original commit message from CVS:
* gst/mpegaudioparse/gstmpegaudioparse.c: (gst_mp3parse_reset),
(gst_mp3parse_emit_frame), (gst_mp3parse_handle_first_frame),
(mp3parse_total_bytes), (mp3parse_total_time):
* gst/mpegaudioparse/gstmpegaudioparse.h:
Add initial support for reading VBRI headers as found in VBR files
created by some Fraunhofer encoders. Currently we only read the
number of frames and bytes (and calculate duration, etc from this)
but there is also a seek table that we currently don't use.

ChangeLog

@@ -1,3 +1,14 @@
+2008-01-14  Sebastian Dröge  <slomo@circular-chaos.org>
+
+	* gst/mpegaudioparse/gstmpegaudioparse.c: (gst_mp3parse_reset),
+	(gst_mp3parse_emit_frame), (gst_mp3parse_handle_first_frame),
+	(mp3parse_total_bytes), (mp3parse_total_time):
+	* gst/mpegaudioparse/gstmpegaudioparse.h:
+	Add initial support for reading VBRI headers as found in VBR files
+	created by some Fraunhofer encoders. Currently we only read the
+	number of frames and bytes (and calculate duration, etc from this)
+	but there is also a seek table that we currently don't use.
+
 2008-01-14  Sebastian Dröge  <slomo@circular-chaos.org>
 
 	Patch by: Mark Nauwelaerts <manauw at syknet dot be>

gst/mpegaudioparse/gstmpegaudioparse.c

@@ -267,6 +267,17 @@ gst_mp3parse_reset (GstMPEGAudioParse * mp3parse)
 
   mp3parse->xing_flags = 0;
   mp3parse->xing_bitrate = 0;
+  mp3parse->xing_frames = 0;
+  mp3parse->xing_total_time = 0;
+  mp3parse->xing_bytes = 0;
+  mp3parse->xing_vbr_scale = 0;
+  memset (mp3parse->xing_seek_table, 0, 100);
+  memset (mp3parse->xing_seek_table_inverse, 0, 256);
+
+  mp3parse->vbri_bitrate = 0;
+  mp3parse->vbri_frames = 0;
+  mp3parse->vbri_total_time = 0;
+  mp3parse->vbri_bytes = 0;
 
   if (mp3parse->seek_table) {
     g_list_foreach (mp3parse->seek_table, (GFunc) g_free, NULL);
@@ -573,6 +584,8 @@ gst_mp3parse_emit_frame (GstMPEGAudioParse * mp3parse, guint size)
   /* Post a bitrate tag if we need to before pushing the buffer */
   if (mp3parse->xing_bitrate != 0)
     bitrate = mp3parse->xing_bitrate;
+  else if (mp3parse->vbri_bitrate != 0)
+    bitrate = mp3parse->vbri_bitrate;
   else
     bitrate = mp3parse->avg_bitrate;
 
@@ -647,8 +660,9 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
   gchar *codec;
   const guint32 xing_id = 0x58696e67;   /* 'Xing' in hex */
   const guint32 info_id = 0x496e666f;   /* 'Info' in hex - found in LAME CBR files */
-  const guint XING_HDR_MIN = 8;
+  const guint32 vbri_id = 0x56425249;   /* 'VBRI' in hex */
-  gint xing_offset;
+
+  gint offset;
 
   guint64 avail;
   guint32 read_id;
@@ -678,34 +692,34 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
   /* Check first frame for Xing info */
   if (mp3parse->version == 1) { /* MPEG-1 file */
     if (mp3parse->channels == 1)
-      xing_offset = 0x11;
+      offset = 0x11;
     else
-      xing_offset = 0x20;
+      offset = 0x20;
   } else {                      /* MPEG-2 header */
     if (mp3parse->channels == 1)
-      xing_offset = 0x09;
+      offset = 0x09;
     else
-      xing_offset = 0x11;
+      offset = 0x11;
   }
   /* Skip the 4 bytes of the MP3 header too */
-  xing_offset += 4;
+  offset += 4;
 
   /* Check if we have enough data to read the Xing header */
   avail = gst_adapter_available (mp3parse->adapter);
 
-  if (avail < xing_offset + XING_HDR_MIN)
+  if (avail < offset + 8)
     return;
 
-  data = gst_adapter_peek (mp3parse->adapter, xing_offset + XING_HDR_MIN);
+  data = gst_adapter_peek (mp3parse->adapter, offset + 8);
   if (data == NULL)
     return;
   /* The header starts at the provided offset */
-  data += xing_offset;
+  data += offset;
 
   read_id = GST_READ_UINT32_BE (data);
   if (read_id == xing_id || read_id == info_id) {
     guint32 xing_flags;
-    guint bytes_needed = xing_offset + XING_HDR_MIN;
+    guint bytes_needed = offset + 8;
     gint64 total_bytes;
     GstClockTime total_time;
 
@@ -730,7 +744,7 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
     GST_DEBUG_OBJECT (mp3parse, "Reading Xing header");
     mp3parse->xing_flags = xing_flags;
     data = gst_adapter_peek (mp3parse->adapter, bytes_needed);
-    data += xing_offset + XING_HDR_MIN;
+    data += offset + 8;
 
     if (xing_flags & XING_FRAMES_FLAG) {
       mp3parse->xing_frames = GST_READ_UINT32_BE (data);
@@ -832,10 +846,105 @@ gst_mp3parse_handle_first_frame (GstMPEGAudioParse * mp3parse)
       mp3parse->xing_vbr_scale = 0;
 
     GST_DEBUG_OBJECT (mp3parse, "Xing header reported %u frames, time %"
-        G_GUINT64_FORMAT ", vbr scale %u", mp3parse->xing_frames,
+        GST_TIME_FORMAT ", %u bytes, vbr scale %u", mp3parse->xing_frames,
-        mp3parse->xing_total_time, mp3parse->xing_vbr_scale);
+        GST_TIME_ARGS (mp3parse->xing_total_time), mp3parse->xing_bytes,
+        mp3parse->xing_vbr_scale);
+  } else if (read_id == vbri_id) {
+    gint64 total_bytes, total_frames;
+    GstClockTime total_time;
+
+    /* guint16 nseek_points; */
+
+    GST_DEBUG_OBJECT (mp3parse, "Found VBRI header marker 0x%x", vbri_id);
+    if (avail < offset + 26) {
+      GST_DEBUG_OBJECT (mp3parse,
+          "Not enough data to read VBRI header (need %d)", offset + 26);
+      return;
+    }
+
+    GST_DEBUG_OBJECT (mp3parse, "Reading VBRI header");
+    data = gst_adapter_peek (mp3parse->adapter, offset + 26);
+    data += offset + 4;
+
+    g_print ("0x%x %c\n", *(data - 1), *(data - 1));
+
+    if (GST_READ_UINT16_BE (data) != 0x0001) {
+      GST_DEBUG_OBJECT (mp3parse,
+          "Unsupported VBRI version 0x%x", GST_READ_UINT16_BE (data));
+      return;
+    }
+    data += 2;
+
+    /* Skip encoder delay */
+    data += 2;
+
+    /* Skip quality */
+    data += 2;
+
+    total_bytes = GST_READ_UINT32_BE (data);
+    if (total_bytes != 0)
+      mp3parse->vbri_bytes = total_bytes;
+    data += 4;
+
+    total_frames = GST_READ_UINT32_BE (data);
+    if (total_frames != 0) {
+      mp3parse->vbri_frames = total_frames;
+      mp3parse->vbri_total_time = gst_util_uint64_scale (GST_SECOND,
+          (guint64) (mp3parse->vbri_frames) * (mp3parse->spf), mp3parse->rate);
+    }
+    data += 4;
+
+    /* If we know the upstream size and duration, compute the 
+     * total bitrate, rounded up to the nearest kbit/sec */
+    if (mp3parse_total_time (mp3parse, &total_time) &&
+        mp3parse_total_bytes (mp3parse, &total_bytes)) {
+      mp3parse->vbri_bitrate = gst_util_uint64_scale (total_bytes,
+          8 * GST_SECOND, total_time);
+      mp3parse->vbri_bitrate += 500;
+      mp3parse->vbri_bitrate -= mp3parse->vbri_bitrate % 1000;
+    }
+
+    /* TODO: Parse seek table and use everywhere.
+     *       See http://groups.google.com/group/alt.music.mp3/browse_thread/thread/4036a2ad8f2ed55d/a528fc7afdf353f6?#a528fc7afdf353f6
+     */
+#if 0
+    nseek_points = GST_READ_UINT16_BE (data);
+    data += 2;
+
+    if (GST_READ_UINT32_BE (data) != 0x0102) {
+      GST_DEBUG_OBJECT (mp3parse, "Unsupported VBRI seek table");
+      return;
+    } else if (nseek_points > 0) {
+      guint stride;
+
+      data += 4;
+
+      stride = GST_READ_UINT16_BE (data);
+      if (stride == 0) {
+        GST_DEBUG_OBJECT (mp3parse, "Unsupported VBRI seek table");
+        return;
+      }
+
+      if (avail < offset + 26 + nseek_points * 2) {
+        GST_DEBUG_OBJECT (mp3parse,
+            "Not enough data to read VBRI seek table (need %d)",
+            offset + 26 + nseek_points * 2);
+        return;
+      }
+
+      data =
+          gst_adapter_peek (mp3parse->adapter, offset + 26 + nseek_points * 2);
+      data += offset + 26;
+
+
+    }
+#endif
+    GST_DEBUG_OBJECT (mp3parse, "VBRI header reported %u frames, time %"
+        GST_TIME_FORMAT ", bytes %u", mp3parse->vbri_frames,
+        GST_TIME_ARGS (mp3parse->vbri_total_time), mp3parse->vbri_bytes);
   } else {
-    GST_DEBUG_OBJECT (mp3parse, "Xing header not found in first frame");
+    GST_DEBUG_OBJECT (mp3parse,
+        "Xing, LAME or VBRI header not found in first frame");
   }
 }
 
@@ -1151,6 +1260,11 @@ mp3parse_total_bytes (GstMPEGAudioParse * mp3parse, gint64 * total)
     return TRUE;
   }
 
+  if (mp3parse->vbri_bytes != 0) {
+    *total = mp3parse->vbri_bytes;
+    return TRUE;
+  }
+
   return FALSE;
 }
 
@@ -1166,6 +1280,11 @@ mp3parse_total_time (GstMPEGAudioParse * mp3parse, GstClockTime * total)
     return TRUE;
   }
 
+  if (mp3parse->vbri_total_time != 0) {
+    *total = mp3parse->vbri_total_time;
+    return TRUE;
+  }
+
   /* Calculate time from the measured bitrate */
   if (!mp3parse_total_bytes (mp3parse, &total_bytes))
     return FALSE;

gst/mpegaudioparse/gstmpegaudioparse.h

@@ -103,6 +103,12 @@ struct _GstMPEGAudioParse {
   guint32 xing_vbr_scale;
   guint   xing_bitrate;
 
+  /* VBRI info */
+  guint32 vbri_frames;
+  GstClockTime vbri_total_time;
+  guint32 vbri_bytes;
+  guint vbri_bitrate;
+
   /* Accurate seeking */
   GList *seek_table;
   GMutex *pending_accurate_seeks_lock;