Try to clarify the difference between line size and stride.

5 files changed, 61 insertions, 28 deletions

diff --git a/src/lib/ab_transcoder.cc b/src/lib/ab_transcoder.cc
index a32d82c54..54153ec76 100644
--- a/src/lib/ab_transcoder.cc
+++ b/src/lib/ab_transcoder.cc
@@ -80,14 +80,15 @@ ABTranscoder::process_video (shared_ptr<Image> yuv, int frame, shared_ptr<Subtit
 		for (int i = 0; i < yuv->components(); ++i) {
 			int const line_size = yuv->line_size()[i];
 			int const half_line_size = line_size / 2;
+			int const stride = yuv->stride()[i];
 
 			uint8_t* p = _image->data()[i];
 			uint8_t* q = yuv->data()[i];
 			
 			for (int j = 0; j < yuv->lines (i); ++j) {
 				memcpy (p + half_line_size, q + half_line_size, half_line_size);
-				p += line_size;
-				q += line_size;
+				p += stride;
+				q += stride;
 			}
 		}
 			
diff --git a/src/lib/dcp_video_frame.cc b/src/lib/dcp_video_frame.cc
index 3e5c4b3aa..04735269c 100644
--- a/src/lib/dcp_video_frame.cc
+++ b/src/lib/dcp_video_frame.cc
@@ -188,7 +188,7 @@ DCPVideoFrame::encode_locally ()
 
 	int jn = 0;
 	for (int y = 0; y < _out_size.height; ++y) {
-		uint8_t* p = prepared->data()[0] + y * prepared->line_size()[0];
+		uint8_t* p = prepared->data()[0] + y * prepared->stride()[0];
 		for (int x = 0; x < _out_size.width; ++x) {
 
 			/* In gamma LUT (converting 8-bit input to 12-bit) */
@@ -332,7 +332,7 @@ DCPVideoFrame::encode_remotely (ServerDescription const * serv)
 	socket.write ((uint8_t *) s.str().c_str(), s.str().length() + 1, 30);
 
 	for (int i = 0; i < _input->components(); ++i) {
-		socket.write (_input->data()[i], _input->line_size()[i] * _input->lines(i), 30);
+		socket.write (_input->data()[i], _input->stride()[i] * _input->lines(i), 30);
 	}
 
 	char buffer[32];
diff --git a/src/lib/image.cc b/src/lib/image.cc
index c8849303c..2c0338b53 100644
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -98,9 +98,9 @@ Image::scale (Size out_size, Scaler const * scaler) const
 
 	sws_scale (
 		scale_context,
-		data(), line_size(),
+		data(), stride(),
 		0, size().height,
-		scaled->data (), scaled->line_size ()
+		scaled->data(), scaled->stride()
 		);
 
 	sws_freeContext (scale_context);
@@ -131,9 +131,9 @@ Image::scale_and_convert_to_rgb (Size out_size, int padding, Scaler const * scal
 	/* Scale and convert to RGB from whatever its currently in (which may be RGB) */
 	sws_scale (
 		scale_context,
-		data(), line_size(),
+		data(), stride(),
 		0, size().height,
-		rgb->data (), rgb->line_size ()
+		rgb->data(), rgb->stride()
 		);
 
 	/* Put the image in the right place in a black frame if are padding; this is
@@ -151,8 +151,8 @@ Image::scale_and_convert_to_rgb (Size out_size, int padding, Scaler const * scal
 		uint8_t* q = rgb->data()[0];
 		for (int j = 0; j < rgb->lines(0); ++j) {
 			memcpy (p, q, rgb->line_size()[0]);
-			p += padded_rgb->line_size()[0];
-			q += rgb->line_size()[0];
+			p += padded_rgb->stride()[0];
+			q += rgb->stride()[0];
 		}
 
 		rgb = padded_rgb;
@@ -176,8 +176,8 @@ Image::post_process (string pp) const
 	pp_context* context = pp_get_context (size().width, size().height, PP_FORMAT_420 | PP_CPU_CAPS_MMX2);
 
 	pp_postprocess (
-		(const uint8_t **) data(), line_size(),
-		out->data(), out->line_size(),
+		(const uint8_t **) data(), stride(),
+		out->data(), out->stride(),
 		size().width, size().height,
 		0, 0, mode, context, 0
 		);
@@ -193,13 +193,13 @@ Image::make_black ()
 {
 	switch (_pixel_format) {
 	case PIX_FMT_YUV420P:
-		memset (data()[0], 0, lines(0) * line_size()[0]);
-		memset (data()[1], 0x80, lines(1) * line_size()[1]);
-		memset (data()[2], 0x80, lines(2) * line_size()[2]);
+		memset (data()[0], 0, lines(0) * stride()[0]);
+		memset (data()[1], 0x80, lines(1) * stride()[1]);
+		memset (data()[2], 0x80, lines(2) * stride()[2]);
 		break;
 
 	case PIX_FMT_RGB24:		
-		memset (data()[0], 0, lines(0) * line_size()[0]);
+		memset (data()[0], 0, lines(0) * stride()[0]);
 		break;
 
 	default:
@@ -230,8 +230,8 @@ Image::alpha_blend (shared_ptr<Image> other, Position position)
 	}
 
 	for (int ty = start_ty, oy = start_oy; ty < size().height && oy < other->size().height; ++ty, ++oy) {
-		uint8_t* tp = data()[0] + ty * line_size()[0] + position.x * 3;
-		uint8_t* op = other->data()[0] + oy * other->line_size()[0];
+		uint8_t* tp = data()[0] + ty * stride()[0] + position.x * 3;
+		uint8_t* op = other->data()[0] + oy * other->stride()[0];
 		for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
 			float const alpha = float (op[3]) / 255;
 			tp[0] = (tp[0] * (1 - alpha)) + op[0] * alpha;
@@ -257,25 +257,28 @@ SimpleImage::SimpleImage (PixelFormat p, Size s)
 	_data[0] = _data[1] = _data[2] = _data[3] = 0;
 	_line_size = (int *) av_malloc (4);
 	_line_size[0] = _line_size[1] = _line_size[2] = _line_size[3] = 0;
+	_stride = (int *) av_malloc (4);
+	_stride[0] = _stride[1] = _stride[2] = _stride[3] = 0;
 
 	switch (p) {
 	case PIX_FMT_RGB24:
-		_line_size[0] = round_up (s.width * 3, 32);
+		_line_size[0] = s.width * 3;
 		break;
 	case PIX_FMT_RGBA:
-		_line_size[0] = round_up (s.width * 4, 32);
+		_line_size[0] = s.width * 4;
 		break;
 	case PIX_FMT_YUV420P:
-		_line_size[0] = round_up (s.width, 32);
-		_line_size[1] = round_up (s.width / 2, 32);
-		_line_size[2] = round_up (s.width / 2, 32);
+		_line_size[0] = s.width;
+		_line_size[1] = s.width / 2;
+		_line_size[2] = s.width / 2;
 		break;
 	default:
 		assert (false);
 	}
-	
+
 	for (int i = 0; i < components(); ++i) {
-		_data[i] = (uint8_t *) av_malloc (_line_size[i] * lines (i));
+		_stride[i] = round_up (_line_size[i], 32);
+		_data[i] = (uint8_t *) av_malloc (_stride[i] * lines (i));
 	}
 }
 
@@ -288,6 +291,7 @@ SimpleImage::~SimpleImage ()
 
 	av_free (_data);
 	av_free (_line_size);
+	av_free (_stride);
 }
 
 uint8_t **
@@ -302,6 +306,12 @@ SimpleImage::line_size () const
 	return _line_size;
 }
 
+int *
+SimpleImage::stride () const
+{
+	return _stride;
+}
+
 Size
 SimpleImage::size () const
 {
@@ -333,6 +343,13 @@ FilterBufferImage::line_size () const
 	return _buffer->linesize;
 }
 
+int *
+FilterBufferImage::stride () const
+{
+	/* XXX? */
+	return _buffer->linesize;
+}
+
 Size
 FilterBufferImage::size () const
 {
@@ -377,6 +394,13 @@ RGBFrameImage::line_size () const
 	return _frame->linesize;
 }
 
+int *
+RGBFrameImage::stride () const
+{
+	/* XXX? */
+	return line_size ();
+}
+
 Size
 RGBFrameImage::size () const
 {
diff --git a/src/lib/image.h b/src/lib/image.h
index ea35fa0b9..3e16d43bf 100644
--- a/src/lib/image.h
+++ b/src/lib/image.h
@@ -57,9 +57,12 @@ public:
 	/** @return Array of pointers to arrays of the component data */
 	virtual uint8_t ** data () const = 0;
 
-	/** @return Array of sizes of each line, in pixels */
+	/** @return Array of sizes of the data in each line, in bytes (without any alignment padding bytes) */
 	virtual int * line_size () const = 0;
 
+	/** @return Array of strides for each line (including any alignment padding bytes) */
+	virtual int * stride () const = 0;
+
 	/** @return Size of the image, in pixels */
 	virtual Size size () const = 0;
 
@@ -91,6 +94,7 @@ public:
 
 	uint8_t ** data () const;
 	int * line_size () const;
+	int * stride () const;
 	Size size () const;
 
 private:
@@ -108,12 +112,15 @@ public:
 
 	uint8_t ** data () const;
 	int * line_size () const;
+	int * stride () const;
 	Size size () const;
 	
 private:
 	Size _size; ///< size in pixels
 	uint8_t** _data; ///< array of pointers to components
-	int* _line_size; ///< array of widths of each line, in bytes
+	int* _line_size; ///< array of sizes of the data in each line, in pixels (without any alignment padding bytes)
+	int* _stride; ///< array of strides for each line (including any alignment padding bytes)
+
 };
 
 /** @class RGBFrameImage
@@ -127,6 +134,7 @@ public:
 
 	uint8_t ** data () const;
 	int * line_size () const;
+	int * stride () const;
 	Size size () const;
 	AVFrame * frame () const {
 		return _frame;
diff --git a/src/lib/server.cc b/src/lib/server.cc
index 26b2be7c7..659418b8f 100644
--- a/src/lib/server.cc
+++ b/src/lib/server.cc
@@ -119,7 +119,7 @@ Server::process (shared_ptr<Socket> socket)
 	shared_ptr<Image> image (new SimpleImage (pixel_format, in_size));
 	
 	for (int i = 0; i < image->components(); ++i) {
-		socket->read_definite_and_consume (image->data()[i], image->line_size()[i] * image->lines(i), 30);
+		socket->read_definite_and_consume (image->data()[i], image->stride()[i] * image->lines(i), 30);
 	}
 
 	/* XXX: subtitle */