Untested code to optionally reduce resolution on extracting image frames.

diff --git a/src/picture_asset.cc b/src/picture_asset.cc
index 21da250a63d4bc7d428737c5c8638f1289304af8..4c66bd021f89d38106971c5df2b0ed5efbc3335c 100644 (file)
--- a/src/picture_asset.cc
+++ b/src/picture_asset.cc
@@ -149,8 +149,8 @@ PictureAsset::equals (shared_ptr<const Asset> other, EqualityOptions opt) const
                                }
                                
                                /* Decompress the images to bitmaps */
-                               opj_image_t* image_A = decompress_j2k (const_cast<uint8_t*> (buffer_A.RoData()), buffer_A.Size ());
-                               opj_image_t* image_B = decompress_j2k (const_cast<uint8_t*> (buffer_B.RoData()), buffer_B.Size ());
+                               opj_image_t* image_A = decompress_j2k (const_cast<uint8_t*> (buffer_A.RoData()), buffer_A.Size (), 0);
+                               opj_image_t* image_B = decompress_j2k (const_cast<uint8_t*> (buffer_B.RoData()), buffer_B.Size (), 0);
 
                                /* Compare them */
                                

diff --git a/src/picture_frame.cc b/src/picture_frame.cc
index 87502e5ea75f3ef4c8e37c57b5d997e01415df12..06788da561646a5ce38283ad97657acc12c5d78a 100644 (file)
--- a/src/picture_frame.cc
+++ b/src/picture_frame.cc
@@ -54,14 +54,19 @@ MonoPictureFrame::~MonoPictureFrame ()
        delete _buffer;
 }
 
-/** @return An ARGB representation of this frame.  This is ARGB in the
+/** @param reduce a factor by which to reduce the resolution
+ *  of the image, expressed as a power of two (pass 0 for no
+ *  reduction).
+ *
+ *  @return An ARGB representation of this frame.  This is ARGB in the
  *  Cairo sense, so that each pixel takes up 4 bytes; the first byte
  *  is blue, second green, third red and fourth alpha (always 255).
+ *
  */
 shared_ptr<ARGBFrame>
-MonoPictureFrame::argb_frame () const
+MonoPictureFrame::argb_frame (int reduce) const
 {
-       opj_image_t* xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->RoData()), _buffer->Size());
+       opj_image_t* xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->RoData()), _buffer->Size(), reduce);
        assert (xyz_frame->numcomps == 3);
        shared_ptr<ARGBFrame> f = xyz_to_rgb (xyz_frame);
        opj_image_destroy (xyz_frame);
@@ -92,23 +97,28 @@ StereoPictureFrame::~StereoPictureFrame ()
        delete _buffer;
 }
 
-/** @return An ARGB representation of one of the eyes (left or right)
+/** @param reduce a factor by which to reduce the resolution
+ *  of the image, expressed as a power of two (pass 0 for no
+ *  reduction).
+ *
+ *  @param eye Eye to return (EYE_LEFT or EYE_RIGHT).
+ *
+ *  @return An ARGB representation of one of the eyes (left or right)
  *  of this frame.  This is ARGB in the Cairo sense, so that each
  *  pixel takes up 4 bytes; the first byte is blue, second green,
  *  third red and fourth alpha (always 255).
  *
- *  @param eye Eye to return (EYE_LEFT or EYE_RIGHT).
  */
 shared_ptr<ARGBFrame>
-StereoPictureFrame::argb_frame (Eye eye) const
+StereoPictureFrame::argb_frame (Eye eye, int reduce) const
 {
        opj_image_t* xyz_frame = 0;
        switch (eye) {
        case LEFT:
-               xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->Left.RoData()), _buffer->Left.Size());
+               xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->Left.RoData()), _buffer->Left.Size(), reduce);
                break;
        case RIGHT:
-               xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->Right.RoData()), _buffer->Right.Size());
+               xyz_frame = decompress_j2k (const_cast<uint8_t*> (_buffer->Right.RoData()), _buffer->Right.Size(), reduce);
                break;
        }
        

diff --git a/src/picture_frame.h b/src/picture_frame.h
index d207333a88f68260d48d50a151d1b3b11563023a..07519455f608419efd5abf7a63e53c52d5c013a8 100644 (file)
--- a/src/picture_frame.h
+++ b/src/picture_frame.h
@@ -40,7 +40,7 @@ public:
        MonoPictureFrame (std::string mxf_path, int n);
        ~MonoPictureFrame ();
 
-       boost::shared_ptr<ARGBFrame> argb_frame () const;
+       boost::shared_ptr<ARGBFrame> argb_frame (int reduce = 0) const;
 
 private:
        ASDCP::JP2K::FrameBuffer* _buffer;
@@ -53,7 +53,7 @@ public:
        StereoPictureFrame (std::string mxf_path, int n);
        ~StereoPictureFrame ();
 
-       boost::shared_ptr<ARGBFrame> argb_frame (Eye eye) const;
+       boost::shared_ptr<ARGBFrame> argb_frame (Eye eye, int reduce = 0) const;
 
 private:
        ASDCP::JP2K::SFrameBuffer* _buffer;

diff --git a/src/util.cc b/src/util.cc
index 360974a6db5d0fabaa0fe281303be48b1c0d6f71..c171b2c7f8a6048b45f18fe10b45d5fdf601aa0a 100644 (file)
--- a/src/util.cc
+++ b/src/util.cc
@@ -159,11 +159,12 @@ libdcp::ends_with (string big, string little)
 }
 
 opj_image_t *
-libdcp::decompress_j2k (uint8_t* data, int64_t size)
+libdcp::decompress_j2k (uint8_t* data, int64_t size, int reduce)
 {
        opj_dinfo_t* decoder = opj_create_decompress (CODEC_J2K);
        opj_dparameters_t parameters;
        opj_set_default_decoder_parameters (&parameters);
+       parameters.cp_reduce = reduce;
        opj_setup_decoder (decoder, &parameters);
        opj_cio_t* cio = opj_cio_open ((opj_common_ptr) decoder, data, size);
        opj_image_t* image = opj_decode (decoder, cio);

diff --git a/src/util.h b/src/util.h
index 751152721b50ad7fd1a40b53c374e2cea0e1dc6f..af6a08d671b789025055e83ddb6aab03cd1768d6 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -48,7 +48,7 @@ extern std::string content_kind_to_string (ContentKind kind);
 extern ContentKind content_kind_from_string (std::string kind);
 extern bool ends_with (std::string big, std::string little);
 
-extern opj_image_t* decompress_j2k (uint8_t* data, int64_t size);
+extern opj_image_t* decompress_j2k (uint8_t* data, int64_t size, int reduce);
 extern boost::shared_ptr<ARGBFrame> xyz_to_rgb (opj_image_t* xyz_frame);
 
 }