From d94001b82005e3d58b915d1fb9224db76bbe82f8 Mon Sep 17 00:00:00 2001
From: Hyunjun Ko <zzoon@igalia.com>
Date: Wed, 6 Jul 2016 11:17:23 +0900
Subject: [PATCH] vaapiencode: implement flush() vmethod
MIME-Version: 1.0
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In order to handle correctly seek and other operations, vaapiencode should
flush all the remaining data from the encoder without pushing it downstream.

This patch implements the flush() vmethod, only after of pausing the
source pad task, and restarting it again after the flush stop.

https://bugzilla.gnome.org/show_bug.cgi?id=767176

Signed-off-by: Víctor Manuel Jáquez Leal <victorx.jaquez@intel.com>
---
 gst/vaapi/gstvaapiencode.c | 78 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/gst/vaapi/gstvaapiencode.c b/gst/vaapi/gstvaapiencode.c
index 9d79fd10af..9646f98435 100644
--- a/gst/vaapi/gstvaapiencode.c
+++ b/gst/vaapi/gstvaapiencode.c
@@ -338,6 +338,7 @@ gst_vaapiencode_buffer_loop (GstVaapiEncode * encode)
   if (ret == GST_FLOW_OK || ret == GST_VAAPI_ENCODE_FLOW_TIMEOUT)
     return;
 
+  GST_LOG_OBJECT (encode, "pausing task, reason %s", gst_flow_get_name (ret));
   gst_pad_pause_task (GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode));
 }
 
@@ -370,6 +371,26 @@ gst_vaapiencode_destroy (GstVaapiEncode * encode)
   return TRUE;
 }
 
+static void
+gst_vaapiencode_purge (GstVaapiEncode * encode)
+{
+  GstVaapiCodedBufferProxy *codedbuf_proxy = NULL;
+  GstVaapiEncoderStatus status;
+  GstVideoCodecFrame *out_frame;
+
+  do {
+    status = gst_vaapi_encoder_get_buffer_with_timeout (encode->encoder,
+        &codedbuf_proxy, 0);
+    if (status == GST_VAAPI_ENCODER_STATUS_SUCCESS) {
+      out_frame = gst_vaapi_coded_buffer_proxy_get_user_data (codedbuf_proxy);
+      if (out_frame)
+        gst_video_codec_frame_set_user_data (out_frame, NULL, NULL);
+
+      gst_vaapi_coded_buffer_proxy_unref (codedbuf_proxy);
+    }
+  } while (status == GST_VAAPI_ENCODER_STATUS_SUCCESS);
+}
+
 static gboolean
 ensure_encoder (GstVaapiEncode * encode)
 {
@@ -380,6 +401,9 @@ ensure_encoder (GstVaapiEncode * encode)
 
   g_return_val_if_fail (klass->alloc_encoder, FALSE);
 
+  if (encode->encoder)
+    return FALSE;
+
   encode->encoder = klass->alloc_encoder (encode,
       GST_VAAPI_PLUGIN_BASE_DISPLAY (encode));
   if (!encode->encoder)
@@ -592,6 +616,58 @@ gst_vaapiencode_propose_allocation (GstVideoEncoder * venc, GstQuery * query)
   return TRUE;
 }
 
+static gboolean
+gst_vaapiencode_sink_event (GstVideoEncoder * venc, GstEvent * event)
+{
+  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
+  GstPad *const srcpad = GST_VAAPI_PLUGIN_BASE_SRC_PAD (encode);
+  gboolean ret;
+
+  ret = GST_VIDEO_ENCODER_CLASS (gst_vaapiencode_parent_class)->sink_event
+      (venc, event);
+  if (!ret)
+    return FALSE;
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_FLUSH_START:
+      gst_pad_pause_task (srcpad);
+      break;
+    case GST_EVENT_FLUSH_STOP:
+      ret = gst_pad_start_task (srcpad,
+          (GstTaskFunction) gst_vaapiencode_buffer_loop, encode, NULL);
+      break;
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static gboolean
+gst_vaapiencode_flush (GstVideoEncoder * venc)
+{
+  GstVaapiEncode *const encode = GST_VAAPIENCODE_CAST (venc);
+  GstVaapiEncoderStatus status;
+
+  if (!encode->encoder)
+    return FALSE;
+
+  GST_LOG_OBJECT (encode, "flushing");
+
+  status = gst_vaapi_encoder_flush (encode->encoder);
+  if (status != GST_VAAPI_ENCODER_STATUS_SUCCESS)
+    return FALSE;
+  gst_vaapiencode_purge (encode);
+
+  gst_vaapi_encoder_replace (&encode->encoder, NULL);
+  if (!ensure_encoder (encode))
+    return FALSE;
+  if (!set_codec_state (encode, encode->input_state))
+    return FALSE;
+
+  return TRUE;
+}
+
 static void
 gst_vaapiencode_finalize (GObject * object)
 {
@@ -643,6 +719,8 @@ gst_vaapiencode_class_init (GstVaapiEncodeClass * klass)
   venc_class->getcaps = GST_DEBUG_FUNCPTR (gst_vaapiencode_get_caps);
   venc_class->propose_allocation =
       GST_DEBUG_FUNCPTR (gst_vaapiencode_propose_allocation);
+  venc_class->flush = GST_DEBUG_FUNCPTR (gst_vaapiencode_flush);
+  venc_class->sink_event = GST_DEBUG_FUNCPTR (gst_vaapiencode_sink_event);
 
   klass->get_property = gst_vaapiencode_default_get_property;
   klass->set_property = gst_vaapiencode_default_set_property;