ext/openexr/gstopenexrdec.cpp - mtk-gst-plugins-bad - Git at Google

 /*
  * Copyright (C) 2013 Sebastian Dröge <sebastian@centricular.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public
  * License along with this library; if not, write to the
  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include "gstopenexrdec.h"

 #include <gst/base/base.h>
 #include <string.h>

 #include <ImfRgbaFile.h>
 #include <ImfIO.h>
 using namespace Imf;
 using namespace Imath;

 /* Memory stream reader */
 class MemIStream:public IStream
 {
 public:
   MemIStream (const char *file_name, const guint8 * data,
       gsize size):IStream (file_name), data (data), offset (0), size (size)
   {
   }

   virtual bool read (char c[], int n);
   virtual Int64 tellg ();
   virtual void seekg (Int64 pos);
   virtual void clear ();

 private:
   const guint8 *data;
   gsize offset, size;
 };

 bool MemIStream::read (char c[], int n)
 {
   if (offset + n > size)
     throw
     Iex::InputExc ("Unexpected end of file");

   memcpy (c, data + offset, n);
   offset += n;

   return (offset == size);
 }

 Int64 MemIStream::tellg ()
 {
   return offset;
 }

 void
 MemIStream::seekg (Int64 pos)
 {
   offset = pos;
   if (offset > size)
     offset = size;
 }

 void
 MemIStream::clear ()
 {

 }

 GST_DEBUG_CATEGORY_STATIC (gst_openexr_dec_debug);
 #define GST_CAT_DEFAULT gst_openexr_dec_debug

 static gboolean gst_openexr_dec_start (GstVideoDecoder * decoder);
 static gboolean gst_openexr_dec_stop (GstVideoDecoder * decoder);
 static GstFlowReturn gst_openexr_dec_parse (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos);
 static gboolean gst_openexr_dec_set_format (GstVideoDecoder * decoder,
     GstVideoCodecState * state);
 static GstFlowReturn gst_openexr_dec_handle_frame (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame);
 static gboolean gst_openexr_dec_decide_allocation (GstVideoDecoder * decoder,
     GstQuery * query);

 static GstStaticPadTemplate gst_openexr_dec_sink_template =
 GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS ("image/x-exr")
     );

 static GstStaticPadTemplate gst_openexr_dec_src_template =
 GST_STATIC_PAD_TEMPLATE ("src",
     GST_PAD_SRC,
     GST_PAD_ALWAYS,
     GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("ARGB64"))
     );

 #define parent_class gst_openexr_dec_parent_class
 G_DEFINE_TYPE (GstOpenEXRDec, gst_openexr_dec, GST_TYPE_VIDEO_DECODER);

 static void
 gst_openexr_dec_class_init (GstOpenEXRDecClass * klass)
 {
   GstElementClass *element_class;
   GstVideoDecoderClass *video_decoder_class;

   element_class = (GstElementClass *) klass;
   video_decoder_class = (GstVideoDecoderClass *) klass;

   gst_element_class_add_static_pad_template (element_class, &gst_openexr_dec_src_template);
   gst_element_class_add_static_pad_template (element_class, &gst_openexr_dec_sink_template);

   gst_element_class_set_static_metadata (element_class,
       "OpenEXR decoder",
       "Codec/Decoder/Video",
       "Decode EXR streams", "Sebastian Dröge <sebastian@centricular.com>");

   video_decoder_class->start = GST_DEBUG_FUNCPTR (gst_openexr_dec_start);
   video_decoder_class->stop = GST_DEBUG_FUNCPTR (gst_openexr_dec_stop);
   video_decoder_class->parse = GST_DEBUG_FUNCPTR (gst_openexr_dec_parse);
   video_decoder_class->set_format =
       GST_DEBUG_FUNCPTR (gst_openexr_dec_set_format);
   video_decoder_class->handle_frame =
       GST_DEBUG_FUNCPTR (gst_openexr_dec_handle_frame);
   video_decoder_class->decide_allocation = gst_openexr_dec_decide_allocation;

   GST_DEBUG_CATEGORY_INIT (gst_openexr_dec_debug, "openexrdec", 0,
       "OpenEXR Decoder");
 }

 static void
 gst_openexr_dec_init (GstOpenEXRDec * self)
 {
   GstVideoDecoder *decoder = (GstVideoDecoder *) self;

   gst_video_decoder_set_packetized (decoder, FALSE);
   gst_video_decoder_set_use_default_pad_acceptcaps (GST_VIDEO_DECODER_CAST
       (self), TRUE);
   GST_PAD_SET_ACCEPT_TEMPLATE (GST_VIDEO_DECODER_SINK_PAD (self));
 }

 static gboolean
 gst_openexr_dec_start (GstVideoDecoder * decoder)
 {
   GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);

   GST_DEBUG_OBJECT (self, "Starting");

   return TRUE;
 }

 static gboolean
 gst_openexr_dec_stop (GstVideoDecoder * video_decoder)
 {
   GstOpenEXRDec *self = GST_OPENEXR_DEC (video_decoder);

   GST_DEBUG_OBJECT (self, "Stopping");

   if (self->output_state) {
     gst_video_codec_state_unref (self->output_state);
     self->output_state = NULL;
   }

   if (self->input_state) {
     gst_video_codec_state_unref (self->input_state);
     self->input_state = NULL;
   }

   GST_DEBUG_OBJECT (self, "Stopped");

   return TRUE;
 }

 static GstFlowReturn
 gst_openexr_dec_parse (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
 {
   guint8 data[8];
   gsize size, parsed_size;
   guint32 magic, flags;
   gssize offset;

   size = gst_adapter_available (adapter);

   parsed_size = gst_video_decoder_get_pending_frame_size (decoder);

   GST_DEBUG_OBJECT (decoder, "Parsing OpenEXR image data %" G_GSIZE_FORMAT,
       size);

   if (parsed_size == 0 && size < 8)
     goto need_more_data;

   /* If we did not parse anything yet, check if the frame starts with the header */
   if (parsed_size == 0) {
     gst_adapter_copy (adapter, data, 0, 8);

     magic = GST_READ_UINT32_LE (data);
     flags = GST_READ_UINT32_LE (data + 4);
     if (magic != 0x01312f76 || ((flags & 0xff) != 1 && (flags & 0xff) != 2) || ((flags & 0x200) && (flags & 0x1800))) {
       offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 0, size, NULL);
       if (offset == -1) {
         gst_adapter_flush (adapter, size - 4);
         goto need_more_data;
       }

       /* come back into this function after flushing some data */
       gst_adapter_flush (adapter, offset);
       goto need_more_data;
     }
   } else {
   }

   /* valid header, now let's try to find the next one unless we're EOS */
   if (!at_eos) {
     gboolean found = FALSE;

     while (!found) {
       offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 8, size - 8 - 4, NULL);
       if (offset == -1) {
         gst_video_decoder_add_to_frame (decoder, size - 7);
         goto need_more_data;
       }

       gst_adapter_copy (adapter, data, offset, 8);
       magic = GST_READ_UINT32_LE (data);
       flags = GST_READ_UINT32_LE (data + 4);
       if (magic == 0x01312f76 && ((flags & 0xff) == 1 || (flags & 0xff) == 2) && (!(flags & 0x200) || !(flags & 0x1800)))
         found = TRUE;
     }
     size = offset;
   }

   GST_DEBUG_OBJECT (decoder, "Have complete image of size %" G_GSSIZE_FORMAT, size + parsed_size);

   gst_video_decoder_add_to_frame (decoder, size);

   return gst_video_decoder_have_frame (decoder);

 need_more_data:
   GST_DEBUG_OBJECT (decoder, "Need more data");
   return GST_VIDEO_DECODER_FLOW_NEED_DATA;
 }

 static gboolean
 gst_openexr_dec_set_format (GstVideoDecoder * decoder,
     GstVideoCodecState * state)
 {
   GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);

   GST_DEBUG_OBJECT (self, "Setting format: %" GST_PTR_FORMAT, state->caps);

   if (self->input_state)
     gst_video_codec_state_unref (self->input_state);
   self->input_state = gst_video_codec_state_ref (state);

   return TRUE;
 }

 static GstFlowReturn
 gst_openexr_dec_negotiate (GstOpenEXRDec * self, RgbaInputFile * file)
 {
   GstVideoFormat format;
   gint width, height;
   gfloat par;

   /* TODO: Use displayWindow here and also support output of ARGB_F16 */
   format = GST_VIDEO_FORMAT_ARGB64;
   Box2i dw = file->dataWindow ();
   width = dw.max.x - dw.min.x + 1;
   height = dw.max.y - dw.min.y + 1;
   par = file->pixelAspectRatio ();

   if (!self->output_state ||
       self->output_state->info.finfo->format != format ||
       self->output_state->info.width != width ||
       self->output_state->info.height != height) {
     if (self->output_state)
       gst_video_codec_state_unref (self->output_state);
     self->output_state =
         gst_video_decoder_set_output_state (GST_VIDEO_DECODER (self), format,
         width, height, self->input_state);

     GST_DEBUG_OBJECT (self, "Have image of size %dx%d (par %f)", width, height, par);
     gst_util_double_to_fraction (par, &self->output_state->info.par_n, &self->output_state->info.par_d);

     if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (self)))
       return GST_FLOW_NOT_NEGOTIATED;
   }

   return GST_FLOW_OK;
 }

 static GstFlowReturn
 gst_openexr_dec_handle_frame (GstVideoDecoder * decoder,
     GstVideoCodecFrame * frame)
 {
   GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);
   GstFlowReturn ret = GST_FLOW_OK;
   gint64 deadline;
   GstMapInfo map;
   GstVideoFrame vframe;

   GST_DEBUG_OBJECT (self, "Handling frame");

   deadline = gst_video_decoder_get_max_decode_time (decoder, frame);
   if (deadline < 0) {
     GST_LOG_OBJECT (self, "Dropping too late frame: deadline %" G_GINT64_FORMAT,
         deadline);
     ret = gst_video_decoder_drop_frame (decoder, frame);
     return ret;
   }

   if (!gst_buffer_map (frame->input_buffer, &map, GST_MAP_READ)) {
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, FAILED,
         ("Failed to map input buffer"), (NULL));
     return GST_FLOW_ERROR;
   }

   /* Now read the file and catch any exceptions */
   MemIStream *istr;
   RgbaInputFile *file;
   try {
     istr =
         new
         MemIStream (gst_pad_get_stream_id (GST_VIDEO_DECODER_SINK_PAD
             (decoder)), map.data, map.size);
   }
   catch (Iex::BaseExc& e) {
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, FAILED,
         ("Failed to create input stream"), (NULL));
     return GST_FLOW_ERROR;
   }
   try {
     file = new RgbaInputFile (*istr);
   }
   catch (Iex::BaseExc& e) {
     delete istr;
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, FAILED,
         ("Failed to read OpenEXR stream"), (NULL));
     return GST_FLOW_ERROR;
   }

   ret = gst_openexr_dec_negotiate (self, file);
   if (ret != GST_FLOW_OK) {
     delete file;
     delete istr;
     gst_buffer_unmap (frame->input_buffer, &map);
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, NEGOTIATION,
         ("Failed to negotiate"), (NULL));
     return ret;
   }

   ret = gst_video_decoder_allocate_output_frame (decoder, frame);
   if (ret != GST_FLOW_OK) {
     delete file;
     delete istr;
     gst_buffer_unmap (frame->input_buffer, &map);
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, FAILED,
         ("Failed to allocate output buffer"), (NULL));
     return ret;
   }

   if (!gst_video_frame_map (&vframe, &self->output_state->info,
           frame->output_buffer, GST_MAP_WRITE)) {
     delete file;
     delete istr;
     gst_buffer_unmap (frame->input_buffer, &map);
     gst_video_codec_frame_unref (frame);

     GST_ELEMENT_ERROR (self, CORE, FAILED,
         ("Failed to map output buffer"), (NULL));
     return GST_FLOW_ERROR;
   }

   /* Decode the file */
   Box2i dw = file->dataWindow ();
   int width = dw.max.x - dw.min.x + 1;
   int height = dw.max.y - dw.min.y + 1;
   Rgba *fb = new Rgba[width * height];

   try {
     file->setFrameBuffer (fb - dw.min.x - dw.min.y * width, 1, width);
     file->readPixels (dw.min.y, dw.max.y);
   } catch (Iex::BaseExc& e) {
     delete[](fb);
     delete file;
     delete istr;
     gst_buffer_unmap (frame->input_buffer, &map);
     gst_video_frame_unmap (&vframe);

     GST_ELEMENT_ERROR (self, CORE, FAILED, ("Failed to read pixels"), (NULL));
     return GST_FLOW_ERROR;
   }

   /* And convert from ARGB64_F16 to ARGB64 */
   gint i, j;
   guint16 *dest = (guint16 *) GST_VIDEO_FRAME_PLANE_DATA (&vframe, 0);
   guint dstride = GST_VIDEO_FRAME_PLANE_STRIDE (&vframe, 0);
   Rgba *ptr = fb;

   /* TODO: Use displayWindow here and also support output of ARGB_F16
    * and add a conversion filter element that can change exposure and
    * other things */
   for (i = 0; i < height; i++) {
     for (j = 0; j < width; j++) {
       dest[4 * j + 0] = CLAMP (((float) ptr->a) * 65536, 0, 65535);
       dest[4 * j + 1] = CLAMP (((float) ptr->r) * 65536, 0, 65535);
       dest[4 * j + 2] = CLAMP (((float) ptr->g) * 65536, 0, 65535);
       dest[4 * j + 3] = CLAMP (((float) ptr->b) * 65536, 0, 65535);
       ptr++;
     }
     dest += dstride / 2;
   }

   delete[](fb);
   delete file;
   delete istr;
   gst_buffer_unmap (frame->input_buffer, &map);
   gst_video_frame_unmap (&vframe);

   ret = gst_video_decoder_finish_frame (decoder, frame);

   return ret;
 }

 static gboolean
 gst_openexr_dec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
 {
   GstBufferPool *pool;
   GstStructure *config;

   if (!GST_VIDEO_DECODER_CLASS (parent_class)->decide_allocation (decoder,
           query))
     return FALSE;

   g_assert (gst_query_get_n_allocation_pools (query) > 0);
   gst_query_parse_nth_allocation_pool (query, 0, &pool, NULL, NULL, NULL);
   g_assert (pool != NULL);

   config = gst_buffer_pool_get_config (pool);
   if (gst_query_find_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL)) {
     gst_buffer_pool_config_add_option (config,
         GST_BUFFER_POOL_OPTION_VIDEO_META);
   }
   gst_buffer_pool_set_config (pool, config);
   gst_object_unref (pool);

   return TRUE;
 }
	/*
	* Copyright (C) 2013 Sebastian Dröge <sebastian@centricular.com>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public
	* License along with this library; if not, write to the
	* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include "gstopenexrdec.h"

	#include <gst/base/base.h>
	#include <string.h>

	#include <ImfRgbaFile.h>
	#include <ImfIO.h>
	using namespace Imf;
	using namespace Imath;

	/* Memory stream reader */
	class MemIStream:public IStream
	{
	public:
	MemIStream (const char file_name, const guint8 data,
	gsize size):IStream (file_name), data (data), offset (0), size (size)
	{
	}

	virtual bool read (char c[], int n);
	virtual Int64 tellg ();
	virtual void seekg (Int64 pos);
	virtual void clear ();

	private:
	const guint8 *data;
	gsize offset, size;
	};

	bool MemIStream::read (char c[], int n)
	{
	if (offset + n > size)
	throw
	Iex::InputExc ("Unexpected end of file");

	memcpy (c, data + offset, n);
	offset += n;

	return (offset == size);
	}

	Int64 MemIStream::tellg ()
	{
	return offset;
	}

	void
	MemIStream::seekg (Int64 pos)
	{
	offset = pos;
	if (offset > size)
	offset = size;
	}

	void
	MemIStream::clear ()
	{

	}

	GST_DEBUG_CATEGORY_STATIC (gst_openexr_dec_debug);
	#define GST_CAT_DEFAULT gst_openexr_dec_debug

	static gboolean gst_openexr_dec_start (GstVideoDecoder * decoder);
	static gboolean gst_openexr_dec_stop (GstVideoDecoder * decoder);
	static GstFlowReturn gst_openexr_dec_parse (GstVideoDecoder * decoder,
	GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos);
	static gboolean gst_openexr_dec_set_format (GstVideoDecoder * decoder,
	GstVideoCodecState * state);
	static GstFlowReturn gst_openexr_dec_handle_frame (GstVideoDecoder * decoder,
	GstVideoCodecFrame * frame);
	static gboolean gst_openexr_dec_decide_allocation (GstVideoDecoder * decoder,
	GstQuery * query);

	static GstStaticPadTemplate gst_openexr_dec_sink_template =
	GST_STATIC_PAD_TEMPLATE ("sink",
	GST_PAD_SINK,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS ("image/x-exr")
	);

	static GstStaticPadTemplate gst_openexr_dec_src_template =
	GST_STATIC_PAD_TEMPLATE ("src",
	GST_PAD_SRC,
	GST_PAD_ALWAYS,
	GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("ARGB64"))
	);

	#define parent_class gst_openexr_dec_parent_class
	G_DEFINE_TYPE (GstOpenEXRDec, gst_openexr_dec, GST_TYPE_VIDEO_DECODER);

	static void
	gst_openexr_dec_class_init (GstOpenEXRDecClass * klass)
	{
	GstElementClass *element_class;
	GstVideoDecoderClass *video_decoder_class;

	element_class = (GstElementClass *) klass;
	video_decoder_class = (GstVideoDecoderClass *) klass;

	gst_element_class_add_static_pad_template (element_class, &gst_openexr_dec_src_template);
	gst_element_class_add_static_pad_template (element_class, &gst_openexr_dec_sink_template);

	gst_element_class_set_static_metadata (element_class,
	"OpenEXR decoder",
	"Codec/Decoder/Video",
	"Decode EXR streams", "Sebastian Dröge <sebastian@centricular.com>");

	video_decoder_class->start = GST_DEBUG_FUNCPTR (gst_openexr_dec_start);
	video_decoder_class->stop = GST_DEBUG_FUNCPTR (gst_openexr_dec_stop);
	video_decoder_class->parse = GST_DEBUG_FUNCPTR (gst_openexr_dec_parse);
	video_decoder_class->set_format =
	GST_DEBUG_FUNCPTR (gst_openexr_dec_set_format);
	video_decoder_class->handle_frame =
	GST_DEBUG_FUNCPTR (gst_openexr_dec_handle_frame);
	video_decoder_class->decide_allocation = gst_openexr_dec_decide_allocation;

	GST_DEBUG_CATEGORY_INIT (gst_openexr_dec_debug, "openexrdec", 0,
	"OpenEXR Decoder");
	}

	static void
	gst_openexr_dec_init (GstOpenEXRDec * self)
	{
	GstVideoDecoder decoder = (GstVideoDecoder ) self;

	gst_video_decoder_set_packetized (decoder, FALSE);
	gst_video_decoder_set_use_default_pad_acceptcaps (GST_VIDEO_DECODER_CAST
	(self), TRUE);
	GST_PAD_SET_ACCEPT_TEMPLATE (GST_VIDEO_DECODER_SINK_PAD (self));
	}

	static gboolean
	gst_openexr_dec_start (GstVideoDecoder * decoder)
	{
	GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);

	GST_DEBUG_OBJECT (self, "Starting");

	return TRUE;
	}

	static gboolean
	gst_openexr_dec_stop (GstVideoDecoder * video_decoder)
	{
	GstOpenEXRDec *self = GST_OPENEXR_DEC (video_decoder);

	GST_DEBUG_OBJECT (self, "Stopping");

	if (self->output_state) {
	gst_video_codec_state_unref (self->output_state);
	self->output_state = NULL;
	}

	if (self->input_state) {
	gst_video_codec_state_unref (self->input_state);
	self->input_state = NULL;
	}

	GST_DEBUG_OBJECT (self, "Stopped");

	return TRUE;
	}

	static GstFlowReturn
	gst_openexr_dec_parse (GstVideoDecoder * decoder,
	GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
	{
	guint8 data[8];
	gsize size, parsed_size;
	guint32 magic, flags;
	gssize offset;

	size = gst_adapter_available (adapter);

	parsed_size = gst_video_decoder_get_pending_frame_size (decoder);

	GST_DEBUG_OBJECT (decoder, "Parsing OpenEXR image data %" G_GSIZE_FORMAT,
	size);

	if (parsed_size == 0 && size < 8)
	goto need_more_data;

	/* If we did not parse anything yet, check if the frame starts with the header */
	if (parsed_size == 0) {
	gst_adapter_copy (adapter, data, 0, 8);

	magic = GST_READ_UINT32_LE (data);
	flags = GST_READ_UINT32_LE (data + 4);
	if (magic != 0x01312f76 \|\| ((flags & 0xff) != 1 && (flags & 0xff) != 2) \|\| ((flags & 0x200) && (flags & 0x1800))) {
	offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 0, size, NULL);
	if (offset == -1) {
	gst_adapter_flush (adapter, size - 4);
	goto need_more_data;
	}

	/* come back into this function after flushing some data */
	gst_adapter_flush (adapter, offset);
	goto need_more_data;
	}
	} else {
	}

	/* valid header, now let's try to find the next one unless we're EOS */
	if (!at_eos) {
	gboolean found = FALSE;

	while (!found) {
	offset = gst_adapter_masked_scan_uint32_peek (adapter, 0xffffffff, 0x762f3101, 8, size - 8 - 4, NULL);
	if (offset == -1) {
	gst_video_decoder_add_to_frame (decoder, size - 7);
	goto need_more_data;
	}

	gst_adapter_copy (adapter, data, offset, 8);
	magic = GST_READ_UINT32_LE (data);
	flags = GST_READ_UINT32_LE (data + 4);
	if (magic == 0x01312f76 && ((flags & 0xff) == 1 \|\| (flags & 0xff) == 2) && (!(flags & 0x200) \|\| !(flags & 0x1800)))
	found = TRUE;
	}
	size = offset;
	}

	GST_DEBUG_OBJECT (decoder, "Have complete image of size %" G_GSSIZE_FORMAT, size + parsed_size);

	gst_video_decoder_add_to_frame (decoder, size);

	return gst_video_decoder_have_frame (decoder);

	need_more_data:
	GST_DEBUG_OBJECT (decoder, "Need more data");
	return GST_VIDEO_DECODER_FLOW_NEED_DATA;
	}

	static gboolean
	gst_openexr_dec_set_format (GstVideoDecoder * decoder,
	GstVideoCodecState * state)
	{
	GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);

	GST_DEBUG_OBJECT (self, "Setting format: %" GST_PTR_FORMAT, state->caps);

	if (self->input_state)
	gst_video_codec_state_unref (self->input_state);
	self->input_state = gst_video_codec_state_ref (state);

	return TRUE;
	}

	static GstFlowReturn
	gst_openexr_dec_negotiate (GstOpenEXRDec * self, RgbaInputFile * file)
	{
	GstVideoFormat format;
	gint width, height;
	gfloat par;

	/* TODO: Use displayWindow here and also support output of ARGB_F16 */
	format = GST_VIDEO_FORMAT_ARGB64;
	Box2i dw = file->dataWindow ();
	width = dw.max.x - dw.min.x + 1;
	height = dw.max.y - dw.min.y + 1;
	par = file->pixelAspectRatio ();

	if (!self->output_state \|\|
	self->output_state->info.finfo->format != format \|\|
	self->output_state->info.width != width \|\|
	self->output_state->info.height != height) {
	if (self->output_state)
	gst_video_codec_state_unref (self->output_state);
	self->output_state =
	gst_video_decoder_set_output_state (GST_VIDEO_DECODER (self), format,
	width, height, self->input_state);

	GST_DEBUG_OBJECT (self, "Have image of size %dx%d (par %f)", width, height, par);
	gst_util_double_to_fraction (par, &self->output_state->info.par_n, &self->output_state->info.par_d);

	if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (self)))
	return GST_FLOW_NOT_NEGOTIATED;
	}

	return GST_FLOW_OK;
	}

	static GstFlowReturn
	gst_openexr_dec_handle_frame (GstVideoDecoder * decoder,
	GstVideoCodecFrame * frame)
	{
	GstOpenEXRDec *self = GST_OPENEXR_DEC (decoder);
	GstFlowReturn ret = GST_FLOW_OK;
	gint64 deadline;
	GstMapInfo map;
	GstVideoFrame vframe;

	GST_DEBUG_OBJECT (self, "Handling frame");

	deadline = gst_video_decoder_get_max_decode_time (decoder, frame);
	if (deadline < 0) {
	GST_LOG_OBJECT (self, "Dropping too late frame: deadline %" G_GINT64_FORMAT,
	deadline);
	ret = gst_video_decoder_drop_frame (decoder, frame);
	return ret;
	}

	if (!gst_buffer_map (frame->input_buffer, &map, GST_MAP_READ)) {
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, FAILED,
	("Failed to map input buffer"), (NULL));
	return GST_FLOW_ERROR;
	}

	/* Now read the file and catch any exceptions */
	MemIStream *istr;
	RgbaInputFile *file;
	try {
	istr =
	new
	MemIStream (gst_pad_get_stream_id (GST_VIDEO_DECODER_SINK_PAD
	(decoder)), map.data, map.size);
	}
	catch (Iex::BaseExc& e) {
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, FAILED,
	("Failed to create input stream"), (NULL));
	return GST_FLOW_ERROR;
	}
	try {
	file = new RgbaInputFile (*istr);
	}
	catch (Iex::BaseExc& e) {
	delete istr;
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, FAILED,
	("Failed to read OpenEXR stream"), (NULL));
	return GST_FLOW_ERROR;
	}

	ret = gst_openexr_dec_negotiate (self, file);
	if (ret != GST_FLOW_OK) {
	delete file;
	delete istr;
	gst_buffer_unmap (frame->input_buffer, &map);
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, NEGOTIATION,
	("Failed to negotiate"), (NULL));
	return ret;
	}

	ret = gst_video_decoder_allocate_output_frame (decoder, frame);
	if (ret != GST_FLOW_OK) {
	delete file;
	delete istr;
	gst_buffer_unmap (frame->input_buffer, &map);
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, FAILED,
	("Failed to allocate output buffer"), (NULL));
	return ret;
	}

	if (!gst_video_frame_map (&vframe, &self->output_state->info,
	frame->output_buffer, GST_MAP_WRITE)) {
	delete file;
	delete istr;
	gst_buffer_unmap (frame->input_buffer, &map);
	gst_video_codec_frame_unref (frame);

	GST_ELEMENT_ERROR (self, CORE, FAILED,
	("Failed to map output buffer"), (NULL));
	return GST_FLOW_ERROR;
	}

	/* Decode the file */
	Box2i dw = file->dataWindow ();
	int width = dw.max.x - dw.min.x + 1;
	int height = dw.max.y - dw.min.y + 1;
	Rgba fb = new Rgba[width height];

	try {
	file->setFrameBuffer (fb - dw.min.x - dw.min.y * width, 1, width);
	file->readPixels (dw.min.y, dw.max.y);
	} catch (Iex::BaseExc& e) {
	delete[](fb);
	delete file;
	delete istr;
	gst_buffer_unmap (frame->input_buffer, &map);
	gst_video_frame_unmap (&vframe);

	GST_ELEMENT_ERROR (self, CORE, FAILED, ("Failed to read pixels"), (NULL));
	return GST_FLOW_ERROR;
	}

	/* And convert from ARGB64_F16 to ARGB64 */
	gint i, j;
	guint16 dest = (guint16 ) GST_VIDEO_FRAME_PLANE_DATA (&vframe, 0);
	guint dstride = GST_VIDEO_FRAME_PLANE_STRIDE (&vframe, 0);
	Rgba *ptr = fb;

	/* TODO: Use displayWindow here and also support output of ARGB_F16
	* and add a conversion filter element that can change exposure and
	* other things */
	for (i = 0; i < height; i++) {
	for (j = 0; j < width; j++) {
	dest[4 * j + 0] = CLAMP (((float) ptr->a) * 65536, 0, 65535);
	dest[4 * j + 1] = CLAMP (((float) ptr->r) * 65536, 0, 65535);
	dest[4 * j + 2] = CLAMP (((float) ptr->g) * 65536, 0, 65535);
	dest[4 * j + 3] = CLAMP (((float) ptr->b) * 65536, 0, 65535);
	ptr++;
	}
	dest += dstride / 2;
	}

	delete[](fb);
	delete file;
	delete istr;
	gst_buffer_unmap (frame->input_buffer, &map);
	gst_video_frame_unmap (&vframe);

	ret = gst_video_decoder_finish_frame (decoder, frame);

	return ret;
	}

	static gboolean
	gst_openexr_dec_decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
	{
	GstBufferPool *pool;
	GstStructure *config;

	if (!GST_VIDEO_DECODER_CLASS (parent_class)->decide_allocation (decoder,
	query))
	return FALSE;

	g_assert (gst_query_get_n_allocation_pools (query) > 0);
	gst_query_parse_nth_allocation_pool (query, 0, &pool, NULL, NULL, NULL);
	g_assert (pool != NULL);

	config = gst_buffer_pool_get_config (pool);
	if (gst_query_find_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL)) {
	gst_buffer_pool_config_add_option (config,
	GST_BUFFER_POOL_OPTION_VIDEO_META);
	}
	gst_buffer_pool_set_config (pool, config);
	gst_object_unref (pool);

	return TRUE;
	}