From a135868262f183eecd1957c0053da75cebb956bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Tue, 3 Nov 2015 10:58:35 +0200
Subject: [PATCH] oggdemux: Add GstAudioClippingMeta for Opus for accurate
 start/end clipping

https://bugzilla.gnome.org/show_bug.cgi?id=757153
---
 ext/ogg/Makefile.am    |  1 +
 ext/ogg/gstoggdemux.c  | 30 ++++++++++++++++++++++++++++++
 ext/ogg/gstoggstream.c |  1 +
 ext/ogg/gstoggstream.h |  1 +
 4 files changed, 33 insertions(+)

diff --git a/ext/ogg/Makefile.am b/ext/ogg/Makefile.am
index 1128141c29..05d9063a8c 100644
--- a/ext/ogg/Makefile.am
+++ b/ext/ogg/Makefile.am
@@ -30,6 +30,7 @@ libgstogg_la_LIBADD = \
 	$(top_builddir)/gst-libs/gst/riff/libgstriff-$(GST_API_VERSION).la \
 	$(top_builddir)/gst-libs/gst/tag/libgsttag-$(GST_API_VERSION).la \
 	$(top_builddir)/gst-libs/gst/pbutils/libgstpbutils-$(GST_API_VERSION).la \
+	$(top_builddir)/gst-libs/gst/audio/libgstaudio-$(GST_API_VERSION).la \
 	$(GST_BASE_LIBS) \
 	$(GST_LIBS) \
 	$(OGG_LIBS)
diff --git a/ext/ogg/gstoggdemux.c b/ext/ogg/gstoggdemux.c
index 165420c80e..05cd759770 100644
--- a/ext/ogg/gstoggdemux.c
+++ b/ext/ogg/gstoggdemux.c
@@ -41,6 +41,7 @@
 #include <string.h>
 #include <gst/gst-i18n-plugin.h>
 #include <gst/tag/tag.h>
+#include <gst/audio/audio.h>
 
 #include "gstoggdemux.h"
 
@@ -500,6 +501,7 @@ gst_ogg_demux_chain_peer (GstOggPad * pad, ogg_packet * packet,
   guint64 out_offset, out_offset_end;
   gboolean delta_unit = FALSE;
   gboolean is_header;
+  guint64 clip_start = 0, clip_end = 0;
 
   ret = cret = GST_FLOW_OK;
   GST_DEBUG_OBJECT (pad, "Chaining %d %d %" GST_TIME_FORMAT " %d %p",
@@ -723,9 +725,29 @@ gst_ogg_demux_chain_peer (GstOggPad * pad, ogg_packet * packet,
                 pad->prev_granule);
           else
             out_timestamp = 0;
+
+          if (pad->map.audio_clipping
+              && pad->current_granule < pad->prev_granule + duration) {
+            clip_end = pad->prev_granule + duration - pad->current_granule;
+          }
+          if (pad->map.audio_clipping
+              && pad->current_granule - duration < -pad->map.granule_offset) {
+            if (pad->current_granule >= -pad->map.granule_offset)
+              clip_start = -pad->map.granule_offset;
+            else
+              clip_start = pad->current_granule;
+          }
         } else {
           out_timestamp = gst_ogg_stream_granule_to_time (&pad->map,
               pad->current_granule - duration);
+
+          if (pad->map.audio_clipping
+              && pad->current_granule - duration < -pad->map.granule_offset) {
+            if (pad->current_granule >= -pad->map.granule_offset)
+              clip_start = -pad->map.granule_offset;
+            else
+              clip_start = pad->current_granule;
+          }
         }
         out_duration =
             gst_ogg_stream_granule_to_time (&pad->map,
@@ -751,6 +773,14 @@ gst_ogg_demux_chain_peer (GstOggPad * pad, ogg_packet * packet,
 
   buf = gst_buffer_new_and_alloc (packet->bytes - offset - trim);
 
+  if (pad->map.audio_clipping && (clip_start || clip_end)) {
+    GST_DEBUG_OBJECT (pad,
+        "Adding audio clipping %" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT,
+        clip_start, clip_end);
+    gst_buffer_add_audio_clipping_meta (buf, GST_FORMAT_DEFAULT, clip_start,
+        clip_end);
+  }
+
   /* set delta flag for OGM content */
   if (delta_unit)
     GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DELTA_UNIT);
diff --git a/ext/ogg/gstoggstream.c b/ext/ogg/gstoggstream.c
index 241c9fffb8..d22a377f9e 100644
--- a/ext/ogg/gstoggstream.c
+++ b/ext/ogg/gstoggstream.c
@@ -2000,6 +2000,7 @@ setup_opus_mapper (GstOggStream * pad, ogg_packet * packet)
   pad->granuleshift = 0;
   pad->n_header_packets = 2;
   pad->first_granpos = -1;
+  pad->audio_clipping = TRUE;
 
   /* pre-skip is in samples at 48000 Hz, which matches granule one for one */
   pad->granule_offset = -GST_READ_UINT16_LE (packet->packet + 10);
diff --git a/ext/ogg/gstoggstream.h b/ext/ogg/gstoggstream.h
index 26dc8e0610..d49527ff2e 100644
--- a/ext/ogg/gstoggstream.h
+++ b/ext/ogg/gstoggstream.h
@@ -70,6 +70,7 @@ struct _GstOggStream
   gint bitrate;
   guint64 total_time;
   gboolean is_sparse;
+  gboolean audio_clipping;
 
   GstCaps *caps;