From f2b0b66e396ab604963d9d943b75ee006e0fa1c8 Mon Sep 17 00:00:00 2001
From: Guillaume Desmottes <guillaume.desmottes@collabora.co.uk>
Date: Thu, 6 Jul 2017 14:19:19 +0200
Subject: [PATCH] omxvideoenc/dec: declare latency on zynqultrascaleplus

The OMX specification doesn't provide any API to expose the latency
introduced by encoders and decoders. We implemented this as a custom
extension as declaring the latency is needed for live pipelines like
video conferencing.

https://bugzilla.gnome.org/show_bug.cgi?id=785125
---
 omx/gstomxvideodec.c | 33 +++++++++++++++++++++++++++++++++
 omx/gstomxvideoenc.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/omx/gstomxvideodec.c b/omx/gstomxvideodec.c
index 31be4df..70307ec 100644
--- a/omx/gstomxvideodec.c
+++ b/omx/gstomxvideodec.c
@@ -1987,6 +1987,35 @@ gst_omx_video_dec_negotiate (GstOMXVideoDec * self)
   return (err == OMX_ErrorNone);
 }
 
+#ifdef USE_OMX_TARGET_ZYNQ_USCALE_PLUS
+static void
+gst_omx_video_dec_set_latency (GstOMXVideoDec * self)
+{
+  GstClockTime latency;
+  OMX_ALG_PARAM_REPORTED_LATENCY param;
+  OMX_ERRORTYPE err;
+
+  GST_OMX_INIT_STRUCT (&param);
+  err =
+      gst_omx_component_get_parameter (self->dec,
+      (OMX_INDEXTYPE) OMX_ALG_IndexParamReportedLatency, &param);
+
+  if (err != OMX_ErrorNone) {
+    GST_WARNING_OBJECT (self, "Couldn't retrieve latency: %s (0x%08x)",
+        gst_omx_error_to_string (err), err);
+    return;
+  }
+
+  GST_DEBUG_OBJECT (self, "retrieved latency of %d ms",
+      (guint32) param.nLatency);
+
+  /* Convert to ns */
+  latency = param.nLatency * GST_MSECOND;
+
+  gst_video_encoder_set_latency (GST_VIDEO_ENCODER (self), latency, latency);
+}
+#endif
+
 static gboolean
 gst_omx_video_dec_disable (GstOMXVideoDec * self)
 {
@@ -2282,6 +2311,10 @@ gst_omx_video_dec_set_format (GstVideoDecoder * decoder,
   gst_buffer_replace (&self->codec_data, state->codec_data);
   self->input_state = gst_video_codec_state_ref (state);
 
+#ifdef USE_OMX_TARGET_ZYNQ_USCALE_PLUS
+  gst_omx_video_dec_set_latency (self);
+#endif
+
   self->downstream_flow_ret = GST_FLOW_OK;
   return TRUE;
 }
diff --git a/omx/gstomxvideoenc.c b/omx/gstomxvideoenc.c
index fb53c82..3172903 100644
--- a/omx/gstomxvideoenc.c
+++ b/omx/gstomxvideoenc.c
@@ -944,6 +944,35 @@ gst_omx_video_enc_stop (GstVideoEncoder * encoder)
   return TRUE;
 }
 
+#ifdef USE_OMX_TARGET_ZYNQ_USCALE_PLUS
+static void
+gst_omx_video_enc_set_latency (GstOMXVideoEnc * self)
+{
+  GstClockTime latency;
+  OMX_ALG_PARAM_REPORTED_LATENCY param;
+  OMX_ERRORTYPE err;
+
+  GST_OMX_INIT_STRUCT (&param);
+  err =
+      gst_omx_component_get_parameter (self->enc,
+      (OMX_INDEXTYPE) OMX_ALG_IndexParamReportedLatency, &param);
+
+  if (err != OMX_ErrorNone) {
+    GST_WARNING_OBJECT (self, "Couldn't retrieve latency: %s (0x%08x)",
+        gst_omx_error_to_string (err), err);
+    return;
+  }
+
+  GST_DEBUG_OBJECT (self, "retrieved latency of %d ms",
+      (guint32) param.nLatency);
+
+  /* Convert to ns */
+  latency = param.nLatency * GST_MSECOND;
+
+  gst_video_encoder_set_latency (GST_VIDEO_ENCODER (self), latency, latency);
+}
+#endif
+
 static gboolean
 gst_omx_video_enc_disable (GstOMXVideoEnc * self)
 {
@@ -1329,6 +1358,10 @@ gst_omx_video_enc_set_format (GstVideoEncoder * encoder,
     gst_video_codec_state_unref (self->input_state);
   self->input_state = gst_video_codec_state_ref (state);
 
+#ifdef USE_OMX_TARGET_ZYNQ_USCALE_PLUS
+  gst_omx_video_enc_set_latency (self);
+#endif
+
   self->downstream_flow_ret = GST_FLOW_OK;
   return TRUE;
 }
-- 
2.7.4