using boost::shared_ptr;
using dcp::Size;
+
+/** The memory alignment, in bytes, used for each row of an image if aligment is requested */
+#define ALIGNMENT 64
+
+
int
Image::vertical_factor (int n) const
{
throw PixelFormatError ("line_factor()", _pixel_format);
}
- return pow (2.0f, d->log2_chroma_h);
+ return lrintf(powf(2.0f, d->log2_chroma_h));
}
int
throw PixelFormatError ("sample_size()", _pixel_format);
}
- return pow (2.0f, d->log2_chroma_w);
+ return lrintf(powf(2.0f, d->log2_chroma_w));
}
/** @param n Component index.
return d->nb_components;
}
+
+static
+int
+round_width_for_subsampling (int p, AVPixFmtDescriptor const * desc)
+{
+ return p & ~ ((1 << desc->log2_chroma_w) - 1);
+}
+
+
+static
+int
+round_height_for_subsampling (int p, AVPixFmtDescriptor const * desc)
+{
+ return p & ~ ((1 << desc->log2_chroma_h) - 1);
+}
+
+
/** Crop this image, scale it to `inter_size' and then place it in a black frame of `out_size'.
* @param crop Amount to crop by.
* @param inter_size Size to scale the cropped image to.
shared_ptr<Image> out (new Image(out_format, out_size, out_aligned));
out->make_black ();
+ AVPixFmtDescriptor const * in_desc = av_pix_fmt_desc_get (_pixel_format);
+ if (!in_desc) {
+ throw PixelFormatError ("crop_scale_window()", _pixel_format);
+ }
+
+ /* Round down so that we crop only the number of pixels that is straightforward
+ * considering any subsampling.
+ */
+ Crop rounded_crop(
+ round_width_for_subsampling(crop.left, in_desc),
+ round_width_for_subsampling(crop.right, in_desc),
+ round_height_for_subsampling(crop.top, in_desc),
+ round_height_for_subsampling(crop.bottom, in_desc)
+ );
+
/* Size of the image after any crop */
- dcp::Size const cropped_size = crop.apply (size ());
+ dcp::Size const cropped_size = rounded_crop.apply (size());
/* Scale context for a scale from cropped_size to inter_size */
struct SwsContext* scale_context = sws_getContext (
0, 1 << 16, 1 << 16
);
- AVPixFmtDescriptor const * in_desc = av_pix_fmt_desc_get (_pixel_format);
- if (!in_desc) {
- throw PixelFormatError ("crop_scale_window()", _pixel_format);
- }
-
/* Prepare input data pointers with crop */
uint8_t* scale_in_data[planes()];
for (int c = 0; c < planes(); ++c) {
- /* To work out the crop in bytes, start by multiplying
- the crop by the (average) bytes per pixel. Then
- round down so that we don't crop a subsampled pixel until
- we've cropped all of its Y-channel pixels.
- */
- int const x = lrintf (bytes_per_pixel(c) * crop.left) & ~ ((int) in_desc->log2_chroma_w);
- scale_in_data[c] = data()[c] + x + stride()[c] * (crop.top / vertical_factor(c));
+ int const x = lrintf(bytes_per_pixel(c) * rounded_crop.left);
+ scale_in_data[c] = data()[c] + x + stride()[c] * (rounded_crop.top / vertical_factor(c));
}
- /* Corner of the image within out_size */
- Position<int> const corner ((out_size.width - inter_size.width) / 2, (out_size.height - inter_size.height) / 2);
-
AVPixFmtDescriptor const * out_desc = av_pix_fmt_desc_get (out_format);
if (!out_desc) {
throw PixelFormatError ("crop_scale_window()", out_format);
}
+ /* Corner of the image within out_size */
+ Position<int> const corner (
+ round_width_for_subsampling((out_size.width - inter_size.width) / 2, out_desc),
+ round_height_for_subsampling((out_size.height - inter_size.height) / 2, out_desc)
+ );
+
uint8_t* scale_out_data[out->planes()];
for (int c = 0; c < out->planes(); ++c) {
- /* See the note in the crop loop above */
- int const x = lrintf (out->bytes_per_pixel(c) * corner.x) & ~ ((int) out_desc->log2_chroma_w);
+ int const x = lrintf(out->bytes_per_pixel(c) * corner.x);
scale_out_data[c] = out->data()[c] + x + out->stride()[c] * (corner.y / out->vertical_factor(c));
}
sws_freeContext (scale_context);
- if (crop != Crop() && cropped_size == inter_size && _pixel_format == out_format) {
+ if (rounded_crop != Crop() && cropped_size == inter_size) {
/* We are cropping without any scaling or pixel format conversion, so FFmpeg may have left some
data behind in our image. Clear it out. It may get to the point where we should just stop
trying to be clever with cropping.
*
* @param p Pixel format.
* @param s Size in pixels.
- * @param aligned true to make each row of this image aligned to a 32-byte boundary.
+ * @param aligned true to make each row of this image aligned to a ALIGNMENT-byte boundary.
*/
Image::Image (AVPixelFormat p, dcp::Size s, bool aligned)
: _size (s)
for (int i = 0; i < planes(); ++i) {
_line_size[i] = ceil (_size.width * bytes_per_pixel(i));
- _stride[i] = stride_round_up (i, _line_size, _aligned ? 32 : 1);
+ _stride[i] = stride_round_up (i, _line_size, _aligned ? ALIGNMENT : 1);
/* The assembler function ff_rgb24ToY_avx (in libswscale/x86/input.asm)
uses a 16-byte fetch to read three bytes (R/G/B) of image data.
Further to the above, valgrind is now telling me that ff_rgb24ToY_ssse3
over-reads by more then _avx. I can't follow the code to work out how much,
- so I'll just over-allocate by 32 bytes and have done with it. Empirical
+ so I'll just over-allocate by ALIGNMENT bytes and have done with it. Empirical
testing suggests that it works.
In addition to these concerns, we may read/write as much as a whole extra line
|XXXwrittenXXX|<------line-size------------->|XXXwrittenXXXXXXwrittenXXX
^^^^ out of bounds
*/
- _data[i] = (uint8_t *) wrapped_av_malloc (_stride[i] * (sample_size(i).height + 1) + 32);
+ _data[i] = (uint8_t *) wrapped_av_malloc (_stride[i] * (sample_size(i).height + 1) + ALIGNMENT);
#if HAVE_VALGRIND_MEMCHECK_H
/* The data between the end of the line size and the stride is undefined but processed by
libswscale, causing lots of valgrind errors. Mark it all defined to quell these errors.
*/
- VALGRIND_MAKE_MEM_DEFINED (_data[i], _stride[i] * (sample_size(i).height + 1) + 32);
+ VALGRIND_MAKE_MEM_DEFINED (_data[i], _stride[i] * (sample_size(i).height + 1) + ALIGNMENT);
#endif
}
}
projects / dcpomatic.git / blobdiff