qtmux: Calculate average bitrate for streams

Calculate and use average bitrate for streams when no
bitrate tag was received

gst/isomp4/atoms.c

@@ -2742,6 +2742,56 @@ atom_moov_chunks_add_offset (AtomMOOV * moov, guint32 offset)
   }
 }
 
+void
+atom_trak_update_bitrates (AtomTRAK * trak, guint32 avg_bitrate,
+    guint32 max_bitrate)
+{
+  AtomESDS *esds = NULL;
+  AtomSTSD *stsd;
+  GList *iter;
+  GList *extensioniter = NULL;
+
+  g_return_if_fail (trak != NULL);
+
+  if (avg_bitrate == 0 && max_bitrate == 0)
+    return;
+
+  stsd = &trak->mdia.minf.stbl.stsd;
+  for (iter = stsd->entries; iter; iter = g_list_next (iter)) {
+    SampleTableEntry *entry = iter->data;
+
+    switch (entry->kind) {
+      case AUDIO:{
+        SampleTableEntryMP4A *audioentry = (SampleTableEntryMP4A *) entry;
+        extensioniter = audioentry->extension_atoms;
+        break;
+      }
+      case VIDEO:{
+        SampleTableEntryMP4V *videoentry = (SampleTableEntryMP4V *) entry;
+        extensioniter = videoentry->extension_atoms;
+        break;
+      }
+      default:
+        break;
+    }
+  }
+
+  for (; extensioniter; extensioniter = g_list_next (extensioniter)) {
+    AtomInfo *atominfo = extensioniter->data;
+    if (atominfo->atom->type == FOURCC_esds) {
+      esds = (AtomESDS *) atominfo->atom;
+      break;
+    }
+  }
+
+  if (esds) {
+    if (avg_bitrate && esds->es.dec_conf_desc.avg_bitrate == 0)
+      esds->es.dec_conf_desc.avg_bitrate = avg_bitrate;
+    if (max_bitrate && esds->es.dec_conf_desc.max_bitrate == 0)
+      esds->es.dec_conf_desc.max_bitrate = max_bitrate;
+  }
+}
+
 /*
  * Meta tags functions
  */

gst/isomp4/atoms.h

@@ -906,6 +906,9 @@ void atom_trak_set_video_type (AtomTRAK * trak, AtomsContext * context,
                                VisualSampleEntry * entry, guint32 rate,
                                GList * ext_atoms_list);
 
+void atom_trak_update_bitrates (AtomTRAK * trak, guint32 avg_bitrate,
+                                guint32 max_bitrate);
+
 AtomInfo *   build_codec_data_extension  (guint32 fourcc, const GstBuffer * codec_data);
 AtomInfo *   build_mov_aac_extension     (AtomTRAK * trak, const GstBuffer * codec_data,
                                           guint32 avg_bitrate, guint32 max_bitrate);

gst/isomp4/gstqtmux.c

@@ -367,6 +367,8 @@ gst_qt_mux_pad_reset (GstQTPad * qtpad)
   qtpad->avg_bitrate = 0;
   qtpad->max_bitrate = 0;
   qtpad->ts_n_entries = 0;
+  qtpad->total_duration = 0;
+  qtpad->total_bytes = 0;
 
   qtpad->buf_head = 0;
   qtpad->buf_tail = 0;
@@ -1769,6 +1771,20 @@ gst_qt_mux_stop_file (GstQTMux * qtmux)
             qtpad->last_dts > first_ts)) {
       first_ts = qtpad->last_dts;
     }
+
+    /* update average bitrate of streams if needed */
+    {
+      guint32 avgbitrate = 0;
+      guint32 maxbitrate = qtpad->max_bitrate;
+
+      if (qtpad->avg_bitrate)
+        avgbitrate = qtpad->avg_bitrate;
+      else if (qtpad->total_duration > 0)
+        avgbitrate = (guint32) gst_util_uint64_scale_round (qtpad->total_bytes,
+            8 * GST_SECOND, qtpad->total_duration);
+
+      atom_trak_update_bitrates (qtpad->trak, avgbitrate, maxbitrate);
+    }
   }
 
   if (qtmux->fragment_sequence) {
@@ -2291,6 +2307,12 @@ again:
     duration = MAX (duration, ts);
   }
 
+  /* for computing the avg bitrate */
+  if (G_LIKELY (last_buf)) {
+    pad->total_bytes += GST_BUFFER_SIZE (last_buf);
+    pad->total_duration += duration;
+  }
+
   gst_buffer_replace (&pad->last_buf, buf);
 
   last_dts = gst_util_uint64_scale_round (pad->last_dts,

gst/isomp4/gstqtmux.h

@@ -97,6 +97,10 @@ struct _GstQTPad
   /* bitrates */
   guint32 avg_bitrate, max_bitrate;
 
+  /* for avg bitrate calculation */
+  guint64 total_bytes;
+  guint64 total_duration;
+
   GstBuffer *last_buf;
   /* dts of last_buf */
   GstClockTime last_dts;