From f591361d2fae5358f00a05a08a4437a933a450ef Mon Sep 17 00:00:00 2001
From: Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>
Date: Tue, 29 Mar 2011 10:41:54 +0200
Subject: [PATCH] basevideodecoder: invoke subclass start method at state
 change and use set_format

While this changes API slightly (e.g. actually uses set_format now), which is OK
for unstable API, it has following merits:
* symmetric w.r.t. stop at state change
* in line with other base class practice
* otherwise no subclass method at state change (global activation time)
Moreover, subclassese are either unaffected or trivially adjusted accordingly.
---
 ext/vp8/gstvp8dec.c                      | 14 ++++++++++++++
 gst-libs/gst/video/gstbasevideodecoder.c | 16 +++++++---------
 gst-libs/gst/video/gstbasevideodecoder.h |  5 +----
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/ext/vp8/gstvp8dec.c b/ext/vp8/gstvp8dec.c
index 83a06b3..9b24dbd 100644
--- a/ext/vp8/gstvp8dec.c
+++ b/ext/vp8/gstvp8dec.c
@@ -98,6 +98,8 @@ static void gst_vp8_dec_get_property (GObject * object, guint prop_id,
 
 static gboolean gst_vp8_dec_start (GstBaseVideoDecoder * decoder);
 static gboolean gst_vp8_dec_stop (GstBaseVideoDecoder * decoder);
+static gboolean gst_vp8_dec_set_format (GstBaseVideoDecoder * decoder,
+    GstVideoState * state);
 static gboolean gst_vp8_dec_reset (GstBaseVideoDecoder * decoder);
 static GstFlowReturn gst_vp8_dec_parse_data (GstBaseVideoDecoder * decoder,
     gboolean at_eos);
@@ -175,6 +177,7 @@ gst_vp8_dec_class_init (GstVP8DecClass * klass)
   base_video_decoder_class->start = gst_vp8_dec_start;
   base_video_decoder_class->stop = gst_vp8_dec_stop;
   base_video_decoder_class->reset = gst_vp8_dec_reset;
+  base_video_decoder_class->set_format = gst_vp8_dec_set_format;
   base_video_decoder_class->parse_data = gst_vp8_dec_parse_data;
   base_video_decoder_class->handle_frame = gst_vp8_dec_handle_frame;
 
@@ -275,6 +278,17 @@ gst_vp8_dec_stop (GstBaseVideoDecoder * base_video_decoder)
 }
 
 static gboolean
+gst_vp8_dec_set_format (GstBaseVideoDecoder * decoder, GstVideoState * state)
+{
+  GstVP8Dec *gst_vp8_dec = GST_VP8_DEC (decoder);
+
+  GST_DEBUG_OBJECT (gst_vp8_dec, "set_format");
+  gst_vp8_dec->decoder_inited = FALSE;
+
+  return TRUE;
+}
+
+static gboolean
 gst_vp8_dec_reset (GstBaseVideoDecoder * base_video_decoder)
 {
   GstVP8Dec *decoder;
diff --git a/gst-libs/gst/video/gstbasevideodecoder.c b/gst-libs/gst/video/gstbasevideodecoder.c
index 93ba0c5..945df4a 100644
--- a/gst-libs/gst/video/gstbasevideodecoder.c
+++ b/gst-libs/gst/video/gstbasevideodecoder.c
@@ -161,8 +161,9 @@ gst_base_video_decoder_sink_setcaps (GstPad * pad, GstCaps * caps)
     state->codec_data = gst_value_get_buffer (codec_data);
   }
 
-  if (base_video_decoder_class->start) {
-    ret = base_video_decoder_class->start (base_video_decoder);
+  if (base_video_decoder_class->set_format) {
+    ret = base_video_decoder_class->set_format (base_video_decoder,
+        &GST_BASE_VIDEO_CODEC (base_video_decoder)->state);
   }
 
   g_object_unref (base_video_decoder);
@@ -728,8 +729,6 @@ gst_base_video_decoder_reset (GstBaseVideoDecoder * base_video_decoder)
 
   GST_DEBUG_OBJECT (base_video_decoder, "reset");
 
-  base_video_decoder->started = FALSE;
-
   base_video_decoder->discont = TRUE;
   base_video_decoder->have_sync = FALSE;
 
@@ -818,11 +817,6 @@ gst_base_video_decoder_chain (GstPad * pad, GstBuffer * buf)
     gst_base_video_decoder_reset (base_video_decoder);
   }
 
-  if (!base_video_decoder->started) {
-    klass->start (base_video_decoder);
-    base_video_decoder->started = TRUE;
-  }
-
   if (base_video_decoder->current_frame == NULL) {
     base_video_decoder->current_frame =
         gst_base_video_decoder_new_frame (base_video_decoder);
@@ -917,6 +911,10 @@ gst_base_video_decoder_change_state (GstElement * element,
   base_video_decoder_class = GST_BASE_VIDEO_DECODER_GET_CLASS (element);
 
   switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_PAUSED:
+      if (base_video_decoder_class->start) {
+        base_video_decoder_class->start (base_video_decoder);
+      }
     default:
       break;
   }
diff --git a/gst-libs/gst/video/gstbasevideodecoder.h b/gst-libs/gst/video/gstbasevideodecoder.h
index a500646..d68d0ee 100644
--- a/gst-libs/gst/video/gstbasevideodecoder.h
+++ b/gst-libs/gst/video/gstbasevideodecoder.h
@@ -75,7 +75,6 @@ struct _GstBaseVideoDecoder
 
   gboolean have_sync;
   gboolean discont;
-  gboolean started;
 
   gboolean sink_clipping;
   gboolean do_byte_time;
@@ -117,9 +116,7 @@ struct _GstBaseVideoDecoderClass
 {
   GstBaseVideoCodecClass base_video_codec_class;
 
-  gboolean (*set_format) (GstBaseVideoDecoder *coder, GstVideoFormat,
-      int width, int height, int fps_n, int fps_d,
-      int par_n, int par_d);
+  gboolean (*set_format) (GstBaseVideoDecoder *coder, GstVideoState * state);
   gboolean (*start) (GstBaseVideoDecoder *coder);
   gboolean (*stop) (GstBaseVideoDecoder *coder);
   gboolean (*reset) (GstBaseVideoDecoder *coder);
-- 
2.7.4