C++11 tidying.
[dcpomatic.git] / src / lib / image.cc
index 158bce1d901aab1b7ff3de884ce8b090bb035805..8e6c5717b9064025a1adb03a619731a13835b347 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
 
 */
 
+
 /** @file src/image.cc
  *  @brief A class to describe a video image.
  */
 
-#include "image.h"
+
+#include "compose.hpp"
+#include "dcpomatic_socket.h"
 #include "exceptions.h"
-#include "timer.h"
+#include "image.h"
 #include "rect.h"
+#include "timer.h"
 #include "util.h"
-#include "dcpomatic_socket.h"
+#include "warnings.h"
 #include <dcp/rgb_xyz.h>
 #include <dcp/transfer_function.h>
+DCPOMATIC_DISABLE_WARNINGS
 extern "C" {
-#include <libswscale/swscale.h>
-#include <libavutil/pixfmt.h>
-#include <libavutil/pixdesc.h>
 #include <libavutil/frame.h>
+#include <libavutil/pixdesc.h>
+#include <libavutil/pixfmt.h>
+#include <libswscale/swscale.h>
 }
+DCPOMATIC_ENABLE_WARNINGS
+#include <png.h>
+#if HAVE_VALGRIND_MEMCHECK_H
+#include <valgrind/memcheck.h>
+#endif
 #include <iostream>
 
+
 #include "i18n.h"
 
-using std::string;
-using std::min;
-using std::max;
-using std::cout;
+
 using std::cerr;
+using std::cout;
 using std::list;
+using std::make_shared;
+using std::max;
+using std::min;
 using std::runtime_error;
-using boost::shared_ptr;
+using std::shared_ptr;
+using std::string;
 using dcp::Size;
 
+
+/** The memory alignment, in bytes, used for each row of an image if aligment is requested */
+#define ALIGNMENT 64
+
+/* U/V black value for 8-bit colour */
+static uint8_t const eight_bit_uv =    (1 << 7) - 1;
+/* U/V black value for 9-bit colour */
+static uint16_t const nine_bit_uv =    (1 << 8) - 1;
+/* U/V black value for 10-bit colour */
+static uint16_t const ten_bit_uv =     (1 << 9) - 1;
+/* U/V black value for 16-bit colour */
+static uint16_t const sixteen_bit_uv = (1 << 15) - 1;
+
+
 int
 Image::vertical_factor (int n) const
 {
@@ -57,12 +84,12 @@ Image::vertical_factor (int n) const
                return 1;
        }
 
-       AVPixFmtDescriptor const * d = av_pix_fmt_desc_get(_pixel_format);
+       auto d = av_pix_fmt_desc_get(_pixel_format);
        if (!d) {
                throw PixelFormatError ("line_factor()", _pixel_format);
        }
 
-       return pow (2.0f, d->log2_chroma_h);
+       return lrintf(powf(2.0f, d->log2_chroma_h));
 }
 
 int
@@ -72,12 +99,12 @@ Image::horizontal_factor (int n) const
                return 1;
        }
 
-       AVPixFmtDescriptor const * d = av_pix_fmt_desc_get(_pixel_format);
+       auto d = av_pix_fmt_desc_get(_pixel_format);
        if (!d) {
                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.
@@ -87,8 +114,8 @@ dcp::Size
 Image::sample_size (int n) const
 {
        return dcp::Size (
-               lrint (ceil (static_cast<double>(size().width) / horizontal_factor (n))),
-               lrint (ceil (static_cast<double>(size().height) / vertical_factor (n)))
+               lrint (ceil(static_cast<double>(size().width) / horizontal_factor(n))),
+               lrint (ceil(static_cast<double>(size().height) / vertical_factor(n)))
                );
 }
 
@@ -96,11 +123,15 @@ Image::sample_size (int n) const
 int
 Image::planes () const
 {
-       AVPixFmtDescriptor const * d = av_pix_fmt_desc_get(_pixel_format);
+       auto d = av_pix_fmt_desc_get(_pixel_format);
        if (!d) {
                throw PixelFormatError ("planes()", _pixel_format);
        }
 
+       if (_pixel_format == AV_PIX_FMT_PAL8) {
+               return 2;
+       }
+
        if ((d->flags & AV_PIX_FMT_FLAG_PLANAR) == 0) {
                return 1;
        }
@@ -108,19 +139,46 @@ Image::planes () const
        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.
  *  @param out_size Size of output frame; if this is larger than inter_size there will be black padding.
  *  @param yuv_to_rgb YUV to RGB transformation to use, if required.
+ *  @param video_range Video range of the image.
  *  @param out_format Output pixel format.
  *  @param out_aligned true to make the output image aligned.
+ *  @param out_video_range Video range to use for the output image.
  *  @param fast Try to be fast at the possible expense of quality; at present this means using
  *  fast bilinear rather than bicubic scaling.
  */
 shared_ptr<Image>
 Image::crop_scale_window (
-       Crop crop, dcp::Size inter_size, dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_format, bool out_aligned, bool fast
+       Crop crop,
+       dcp::Size inter_size,
+       dcp::Size out_size,
+       dcp::YUVToRGB yuv_to_rgb,
+       VideoRange video_range,
+       AVPixelFormat out_format,
+       VideoRange out_video_range,
+       bool out_aligned,
+       bool fast
        ) const
 {
        /* Empirical testing suggests that sws_scale() will crash if
@@ -131,36 +189,40 @@ Image::crop_scale_window (
        DCPOMATIC_ASSERT (out_size.width >= inter_size.width);
        DCPOMATIC_ASSERT (out_size.height >= inter_size.height);
 
-       /* Here's an image of out_size.  Below we may write to it starting at an offset so we get some padding.
-          Hence we want to write in the following pattern:
-
-          block start   write start                                  line end
-          |..(padding)..|<------line-size------------->|..(padding)..|
-          |..(padding)..|<------line-size------------->|..(padding)..|
-          |..(padding)..|<------line-size------------->|..(padding)..|
+       auto out = make_shared<Image>(out_format, out_size, out_aligned);
+       out->make_black ();
 
-          where line-size is of the smaller (inter_size) image and the full padded line length is that of
-          out_size.  To get things to work we have to tell FFmpeg that the stride is that of out_size.
-          However some parts of FFmpeg (notably rgb48Toxyz12 in swscale.c) process data for the full
-          specified *stride*.  This does not matter until we get to the last line:
+       auto in_desc = av_pix_fmt_desc_get (_pixel_format);
+       if (!in_desc) {
+               throw PixelFormatError ("crop_scale_window()", _pixel_format);
+       }
 
-          block start   write start                                  line end
-          |..(padding)..|<------line-size------------->|XXXwrittenXXX|
-          |XXXwrittenXXX|<------line-size------------->|XXXwrittenXXX|
-          |XXXwrittenXXX|<------line-size------------->|XXXwrittenXXXXXXwrittenXXX
-                                                                      ^^^^ out of bounds
+       /* Round down so that we crop only the number of pixels that is straightforward
+        * considering any subsampling.
+        */
+       Crop corrected_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)
+               );
 
-          To get around this, we ask Image to overallocate its buffers by the overrun.
-       */
+       /* Also check that we aren't cropping more image than there actually is */
+       if ((corrected_crop.left + corrected_crop.right) >= (size().width - 4)) {
+               corrected_crop.left = 0;
+               corrected_crop.right = size().width - 4;
+       }
 
-       shared_ptr<Image> out (new Image (out_format, out_size, out_aligned, (out_size.width - inter_size.width) / 2));
-       out->make_black ();
+       if ((corrected_crop.top + corrected_crop.bottom) >= (size().height - 4)) {
+               corrected_crop.top = 0;
+               corrected_crop.bottom = size().height - 4;
+       }
 
        /* Size of the image after any crop */
-       dcp::Size const cropped_size = crop.apply (size ());
+       auto const cropped_size = corrected_crop.apply (size());
 
        /* Scale context for a scale from cropped_size to inter_size */
-       struct SwsContext* scale_context = sws_getContext (
+       auto scale_context = sws_getContext (
                        cropped_size.width, cropped_size.height, pixel_format(),
                        inter_size.width, inter_size.height, out_format,
                        fast ? SWS_FAST_BILINEAR : SWS_BICUBIC, 0, 0, 0
@@ -170,42 +232,52 @@ Image::crop_scale_window (
                throw runtime_error (N_("Could not allocate SwsContext"));
        }
 
-       DCPOMATIC_ASSERT (yuv_to_rgb < dcp::YUV_TO_RGB_COUNT);
-       int const lut[dcp::YUV_TO_RGB_COUNT] = {
+       DCPOMATIC_ASSERT (yuv_to_rgb < dcp::YUVToRGB::COUNT);
+       int const lut[static_cast<int>(dcp::YUVToRGB::COUNT)] = {
                SWS_CS_ITU601,
                SWS_CS_ITU709
        };
 
+       /* The 3rd parameter here is:
+          0 -> source range MPEG (i.e. "video", 16-235)
+          1 -> source range JPEG (i.e. "full", 0-255)
+          And the 5th:
+          0 -> destination range MPEG (i.e. "video", 16-235)
+          1 -> destination range JPEG (i.e. "full", 0-255)
+
+          But remember: sws_setColorspaceDetails ignores these
+          parameters unless the both source and destination images
+          are isYUV or isGray.  (If either is not, it uses video range).
+       */
        sws_setColorspaceDetails (
                scale_context,
-               sws_getCoefficients (lut[yuv_to_rgb]), 0,
-               sws_getCoefficients (lut[yuv_to_rgb]), 0,
+               sws_getCoefficients (lut[static_cast<int>(yuv_to_rgb)]), video_range == VideoRange::VIDEO ? 0 : 1,
+               sws_getCoefficients (lut[static_cast<int>(yuv_to_rgb)]), out_video_range == VideoRange::VIDEO ? 0 : 1,
                0, 1 << 16, 1 << 16
                );
 
-       AVPixFmtDescriptor const * desc = av_pix_fmt_desc_get (_pixel_format);
-       if (!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) 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) * corrected_crop.left);
+               scale_in_data[c] = data()[c] + x + stride()[c] * (corrected_crop.top / vertical_factor(c));
+       }
+
+       auto 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 ((out_size.width - inter_size.width) / 2, (out_size.height - inter_size.height) / 2);
+       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) {
-               scale_out_data[c] = out->data()[c] + lrintf (out->bytes_per_pixel(c) * corner.x) + out->stride()[c] * (corner.y / out->vertical_factor(c));
+               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_scale (
@@ -217,6 +289,23 @@ Image::crop_scale_window (
 
        sws_freeContext (scale_context);
 
+       if (corrected_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.
+               */
+               out->make_part_black (corner.x + cropped_size.width, out_size.width - cropped_size.width);
+       }
+
+       if (
+               video_range == VideoRange::VIDEO &&
+               out_video_range == VideoRange::FULL &&
+               av_pix_fmt_desc_get(_pixel_format)->flags & AV_PIX_FMT_FLAG_RGB
+          ) {
+               /* libswscale will not convert video range for RGB sources, so we have to do it ourselves */
+               out->video_range_to_full_range ();
+       }
+
        return out;
 }
 
@@ -241,24 +330,34 @@ Image::scale (dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_fo
        */
        DCPOMATIC_ASSERT (aligned ());
 
-       shared_ptr<Image> scaled (new Image (out_format, out_size, out_aligned));
-
-       struct SwsContext* scale_context = sws_getContext (
+       auto scaled = make_shared<Image>(out_format, out_size, out_aligned);
+       auto scale_context = sws_getContext (
                size().width, size().height, pixel_format(),
                out_size.width, out_size.height, out_format,
                (fast ? SWS_FAST_BILINEAR : SWS_BICUBIC) | SWS_ACCURATE_RND, 0, 0, 0
                );
 
-       DCPOMATIC_ASSERT (yuv_to_rgb < dcp::YUV_TO_RGB_COUNT);
-       int const lut[dcp::YUV_TO_RGB_COUNT] = {
+       DCPOMATIC_ASSERT (yuv_to_rgb < dcp::YUVToRGB::COUNT);
+       int const lut[static_cast<int>(dcp::YUVToRGB::COUNT)] = {
                SWS_CS_ITU601,
                SWS_CS_ITU709
        };
 
+       /* The 3rd parameter here is:
+          0 -> source range MPEG (i.e. "video", 16-235)
+          1 -> source range JPEG (i.e. "full", 0-255)
+          And the 5th:
+          0 -> destination range MPEG (i.e. "video", 16-235)
+          1 -> destination range JPEG (i.e. "full", 0-255)
+
+          But remember: sws_setColorspaceDetails ignores these
+          parameters unless the corresponding image isYUV or isGray.
+          (If it's neither, it uses video range).
+       */
        sws_setColorspaceDetails (
                scale_context,
-               sws_getCoefficients (lut[yuv_to_rgb]), 0,
-               sws_getCoefficients (lut[yuv_to_rgb]), 0,
+               sws_getCoefficients (lut[static_cast<int>(yuv_to_rgb)]), 0,
+               sws_getCoefficients (lut[static_cast<int>(yuv_to_rgb)]), 0,
                0, 1 << 16, 1 << 16
                );
 
@@ -280,7 +379,7 @@ Image::yuv_16_black (uint16_t v, bool alpha)
 {
        memset (data()[0], 0, sample_size(0).height * stride()[0]);
        for (int i = 1; i < 3; ++i) {
-               int16_t* p = reinterpret_cast<int16_t*> (data()[i]);
+               auto p = reinterpret_cast<int16_t*> (data()[i]);
                int const lines = sample_size(i).height;
                for (int y = 0; y < lines; ++y) {
                        /* We divide by 2 here because we are writing 2 bytes at a time */
@@ -303,17 +402,78 @@ Image::swap_16 (uint16_t v)
 }
 
 void
-Image::make_black ()
+Image::make_part_black (int const start, int const width)
 {
-       /* U/V black value for 8-bit colour */
-       static uint8_t const eight_bit_uv =     (1 << 7) - 1;
-       /* U/V black value for 9-bit colour */
-       static uint16_t const nine_bit_uv =     (1 << 8) - 1;
-       /* U/V black value for 10-bit colour */
-       static uint16_t const ten_bit_uv =      (1 << 9) - 1;
-       /* U/V black value for 16-bit colour */
-       static uint16_t const sixteen_bit_uv =  (1 << 15) - 1;
+       auto y_part = [&]() {
+               int const bpp = bytes_per_pixel(0);
+               int const h = sample_size(0).height;
+               int const s = stride()[0];
+               auto p = data()[0];
+               for (int y = 0; y < h; ++y) {
+                       memset (p + start * bpp, 0, width * bpp);
+                       p += s;
+               }
+       };
 
+       switch (_pixel_format) {
+       case AV_PIX_FMT_RGB24:
+       case AV_PIX_FMT_ARGB:
+       case AV_PIX_FMT_RGBA:
+       case AV_PIX_FMT_ABGR:
+       case AV_PIX_FMT_BGRA:
+       case AV_PIX_FMT_RGB555LE:
+       case AV_PIX_FMT_RGB48LE:
+       case AV_PIX_FMT_RGB48BE:
+       case AV_PIX_FMT_XYZ12LE:
+       {
+               int const h = sample_size(0).height;
+               int const bpp = bytes_per_pixel(0);
+               int const s = stride()[0];
+               uint8_t* p = data()[0];
+               for (int y = 0; y < h; y++) {
+                       memset (p + start * bpp, 0, width * bpp);
+                       p += s;
+               }
+               break;
+       }
+       case AV_PIX_FMT_YUV420P:
+       {
+               y_part ();
+               for (int i = 1; i < 3; ++i) {
+                       auto p = data()[i];
+                       int const h = sample_size(i).height;
+                       for (int y = 0; y < h; ++y) {
+                               for (int x = start / 2; x < (start + width) / 2; ++x) {
+                                       p[x] = eight_bit_uv;
+                               }
+                               p += stride()[i];
+                       }
+               }
+               break;
+       }
+       case AV_PIX_FMT_YUV422P10LE:
+       {
+               y_part ();
+               for (int i = 1; i < 3; ++i) {
+                       auto p = reinterpret_cast<int16_t*>(data()[i]);
+                       int const h = sample_size(i).height;
+                       for (int y = 0; y < h; ++y) {
+                               for (int x = start / 2; x < (start + width) / 2; ++x) {
+                                       p[x] = ten_bit_uv;
+                               }
+                               p += stride()[i] / 2;
+                       }
+               }
+               break;
+       }
+       default:
+               throw PixelFormatError ("make_part_black()", _pixel_format);
+       }
+}
+
+void
+Image::make_black ()
+{
        switch (_pixel_format) {
        case AV_PIX_FMT_YUV420P:
        case AV_PIX_FMT_YUV422P:
@@ -429,7 +589,7 @@ Image::make_black ()
 void
 Image::make_transparent ()
 {
-       if (_pixel_format != AV_PIX_FMT_BGRA) {
+       if (_pixel_format != AV_PIX_FMT_BGRA && _pixel_format != AV_PIX_FMT_RGBA) {
                throw PixelFormatError ("make_transparent()", _pixel_format);
        }
 
@@ -439,8 +599,11 @@ Image::make_transparent ()
 void
 Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
 {
-       /* We're blending BGRA images; first byte is blue, second byte is green, third byte red, fourth byte alpha */
-       DCPOMATIC_ASSERT (other->pixel_format() == AV_PIX_FMT_BGRA);
+       /* We're blending RGBA or BGRA images */
+       DCPOMATIC_ASSERT (other->pixel_format() == AV_PIX_FMT_BGRA || other->pixel_format() == AV_PIX_FMT_RGBA);
+       int const blue = other->pixel_format() == AV_PIX_FMT_BGRA ? 0 : 2;
+       int const red = other->pixel_format() == AV_PIX_FMT_BGRA ? 2 : 0;
+
        int const other_bpp = 4;
 
        int start_tx = position.x;
@@ -469,9 +632,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                        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] = op[2] * alpha + tp[0] * (1 - alpha);
+                               tp[0] = op[red] * alpha + tp[0] * (1 - alpha);
                                tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-                               tp[2] = op[0] * alpha + tp[2] * (1 - alpha);
+                               tp[2] = op[blue] * alpha + tp[2] * (1 - alpha);
 
                                tp += this_bpp;
                                op += other_bpp;
@@ -487,9 +650,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                        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] = op[0] * alpha + tp[0] * (1 - alpha);
+                               tp[0] = op[blue] * alpha + tp[0] * (1 - alpha);
                                tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-                               tp[2] = op[2] * alpha + tp[2] * (1 - alpha);
+                               tp[2] = op[red] * alpha + tp[2] * (1 - alpha);
                                tp[3] = op[3] * alpha + tp[3] * (1 - alpha);
 
                                tp += this_bpp;
@@ -506,9 +669,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                        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] = op[2] * alpha + tp[0] * (1 - alpha);
+                               tp[0] = op[red] * alpha + tp[0] * (1 - alpha);
                                tp[1] = op[1] * alpha + tp[1] * (1 - alpha);
-                               tp[2] = op[0] * alpha + tp[2] * (1 - alpha);
+                               tp[2] = op[blue] * alpha + tp[2] * (1 - alpha);
                                tp[3] = op[3] * alpha + tp[3] * (1 - alpha);
 
                                tp += this_bpp;
@@ -526,9 +689,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                        for (int tx = start_tx, ox = start_ox; tx < size().width && ox < other->size().width; ++tx, ++ox) {
                                float const alpha = float (op[3]) / 255;
                                /* Blend high bytes */
-                               tp[1] = op[2] * alpha + tp[1] * (1 - alpha);
+                               tp[1] = op[red] * alpha + tp[1] * (1 - alpha);
                                tp[3] = op[1] * alpha + tp[3] * (1 - alpha);
-                               tp[5] = op[0] * alpha + tp[5] * (1 - alpha);
+                               tp[5] = op[blue] * alpha + tp[5] * (1 - alpha);
 
                                tp += this_bpp;
                                op += other_bpp;
@@ -538,7 +701,7 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
        }
        case AV_PIX_FMT_XYZ12LE:
        {
-               dcp::ColourConversion conv = dcp::ColourConversion::srgb_to_xyz();
+               auto conv = dcp::ColourConversion::srgb_to_xyz();
                double fast_matrix[9];
                dcp::combined_rgb_to_xyz (conv, fast_matrix);
                double const * lut_in = conv.in()->lut (8, false);
@@ -551,9 +714,9 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
                                float const alpha = float (op[3]) / 255;
 
                                /* Convert sRGB to XYZ; op is BGRA.  First, input gamma LUT */
-                               double const r = lut_in[op[2]];
+                               double const r = lut_in[op[red]];
                                double const g = lut_in[op[1]];
-                               double const b = lut_in[op[0]];
+                               double const b = lut_in[op[blue]];
 
                                /* RGB to XYZ, including Bradford transform and DCI companding */
                                double const x = max (0.0, min (65535.0, r * fast_matrix[0] + g * fast_matrix[1] + b * fast_matrix[2]));
@@ -573,7 +736,7 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
        }
        case AV_PIX_FMT_YUV420P:
        {
-               shared_ptr<Image> yuv = other->convert_pixel_format (dcp::YUV_TO_RGB_REC709, _pixel_format, false, false);
+               auto yuv = other->convert_pixel_format (dcp::YUVToRGB::REC709, _pixel_format, false, false);
                dcp::Size const ts = size();
                dcp::Size const os = yuv->size();
                for (int ty = start_ty, oy = start_oy; ty < ts.height && oy < os.height; ++ty, ++oy) {
@@ -608,7 +771,7 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
        }
        case AV_PIX_FMT_YUV420P10:
        {
-               shared_ptr<Image> yuv = other->convert_pixel_format (dcp::YUV_TO_RGB_REC709, _pixel_format, false, false);
+               auto yuv = other->convert_pixel_format (dcp::YUVToRGB::REC709, _pixel_format, false, false);
                dcp::Size const ts = size();
                dcp::Size const os = yuv->size();
                for (int ty = start_ty, oy = start_oy; ty < ts.height && oy < os.height; ++ty, ++oy) {
@@ -643,7 +806,7 @@ Image::alpha_blend (shared_ptr<const Image> other, Position<int> position)
        }
        case AV_PIX_FMT_YUV422P10LE:
        {
-               shared_ptr<Image> yuv = other->convert_pixel_format (dcp::YUV_TO_RGB_REC709, _pixel_format, false, false);
+               auto yuv = other->convert_pixel_format (dcp::YUVToRGB::REC709, _pixel_format, false, false);
                dcp::Size const ts = size();
                dcp::Size const os = yuv->size();
                for (int ty = start_ty, oy = start_oy; ty < ts.height && oy < os.height; ++ty, ++oy) {
@@ -723,7 +886,7 @@ Image::write_to_socket (shared_ptr<Socket> socket) const
 float
 Image::bytes_per_pixel (int c) const
 {
-       AVPixFmtDescriptor const * d = av_pix_fmt_desc_get(_pixel_format);
+       auto d = av_pix_fmt_desc_get(_pixel_format);
        if (!d) {
                throw PixelFormatError ("bytes_per_pixel()", _pixel_format);
        }
@@ -771,14 +934,12 @@ Image::bytes_per_pixel (int c) const
  *
  *  @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 extra_pixels Amount of extra "run-off" memory to allocate at the end of each plane in pixels.
+ *  @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, int extra_pixels)
+Image::Image (AVPixelFormat p, dcp::Size s, bool aligned)
        : _size (s)
        , _pixel_format (p)
        , _aligned (aligned)
-       , _extra_pixels (extra_pixels)
 {
        allocate ();
 }
@@ -797,7 +958,7 @@ Image::allocate ()
 
        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.
@@ -810,18 +971,47 @@ Image::allocate ()
 
                   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
+                  at the end of each plane in cases where we are messing with offsets in order to
+                  do pad or crop.  To solve this we over-allocate by an extra _stride[i] bytes.
+
+                  As an example: we may write to images starting at an offset so we get some padding.
+                  Hence we want to write in the following pattern:
+
+                  block start   write start                                  line end
+                  |..(padding)..|<------line-size------------->|..(padding)..|
+                  |..(padding)..|<------line-size------------->|..(padding)..|
+                  |..(padding)..|<------line-size------------->|..(padding)..|
+
+                  where line-size is of the smaller (inter_size) image and the full padded line length is that of
+                  out_size.  To get things to work we have to tell FFmpeg that the stride is that of out_size.
+                  However some parts of FFmpeg (notably rgb48Toxyz12 in swscale.c) process data for the full
+                  specified *stride*.  This does not matter until we get to the last line:
+
+                  block start   write start                                  line end
+                  |..(padding)..|<------line-size------------->|XXXwrittenXXX|
+                  |XXXwrittenXXX|<------line-size------------->|XXXwrittenXXX|
+                  |XXXwrittenXXX|<------line-size------------->|XXXwrittenXXXXXXwrittenXXX
+                                                                              ^^^^ out of bounds
+               */
+               _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.
                */
-               _data[i] = (uint8_t *) wrapped_av_malloc (_stride[i] * sample_size(i).height + _extra_pixels * bytes_per_pixel(i) + 32);
+               VALGRIND_MAKE_MEM_DEFINED (_data[i], _stride[i] * (sample_size(i).height + 1) + ALIGNMENT);
+#endif
        }
 }
 
 Image::Image (Image const & other)
-       : _size (other._size)
+       : std::enable_shared_from_this<Image>(other)
+       , _size (other._size)
        , _pixel_format (other._pixel_format)
        , _aligned (other._aligned)
-       , _extra_pixels (other._extra_pixels)
 {
        allocate ();
 
@@ -837,12 +1027,13 @@ Image::Image (Image const & other)
        }
 }
 
-Image::Image (AVFrame* frame)
+Image::Image (AVFrame const * frame)
        : _size (frame->width, frame->height)
-       , _pixel_format (static_cast<AVPixelFormat> (frame->format))
+       , _pixel_format (static_cast<AVPixelFormat>(frame->format))
        , _aligned (true)
-       , _extra_pixels (0)
 {
+       DCPOMATIC_ASSERT (_pixel_format != AV_PIX_FMT_NONE);
+
        allocate ();
 
        for (int i = 0; i < planes(); ++i) {
@@ -862,7 +1053,6 @@ Image::Image (shared_ptr<const Image> other, bool aligned)
        : _size (other->_size)
        , _pixel_format (other->_pixel_format)
        , _aligned (aligned)
-       , _extra_pixels (other->_extra_pixels)
 {
        allocate ();
 
@@ -904,10 +1094,8 @@ Image::swap (Image & other)
        }
 
        std::swap (_aligned, other._aligned);
-       std::swap (_extra_pixels, other._extra_pixels);
 }
 
-/** Destroy a Image */
 Image::~Image ()
 {
        for (int i = 0; i < planes(); ++i) {
@@ -949,11 +1137,12 @@ Image::aligned () const
        return _aligned;
 }
 
+
 PositionImage
 merge (list<PositionImage> images)
 {
        if (images.empty ()) {
-               return PositionImage ();
+               return {};
        }
 
        if (images.size() == 1) {
@@ -961,19 +1150,20 @@ merge (list<PositionImage> images)
        }
 
        dcpomatic::Rect<int> all (images.front().position, images.front().image->size().width, images.front().image->size().height);
-       for (list<PositionImage>::const_iterator i = images.begin(); i != images.end(); ++i) {
-               all.extend (dcpomatic::Rect<int> (i->position, i->image->size().width, i->image->size().height));
+       for (auto const& i: images) {
+               all.extend (dcpomatic::Rect<int>(i.position, i.image->size().width, i.image->size().height));
        }
 
-       shared_ptr<Image> merged (new Image (images.front().image->pixel_format (), dcp::Size (all.width, all.height), true));
+       auto merged = make_shared<Image>(images.front().image->pixel_format(), dcp::Size(all.width, all.height), true);
        merged->make_transparent ();
-       for (list<PositionImage>::const_iterator i = images.begin(); i != images.end(); ++i) {
-               merged->alpha_blend (i->image, i->position - all.position());
+       for (auto const& i: images) {
+               merged->alpha_blend (i.image, i.position - all.position());
        }
 
        return PositionImage (merged, all.position ());
 }
 
+
 bool
 operator== (Image const & a, Image const & b)
 {
@@ -1008,49 +1198,61 @@ operator== (Image const & a, Image const & b)
 void
 Image::fade (float f)
 {
+       /* U/V black value for 8-bit colour */
+       static int const eight_bit_uv =    (1 << 7) - 1;
+       /* U/V black value for 10-bit colour */
+       static uint16_t const ten_bit_uv = (1 << 9) - 1;
+
        switch (_pixel_format) {
        case AV_PIX_FMT_YUV420P:
-       case AV_PIX_FMT_YUV422P:
-       case AV_PIX_FMT_YUV444P:
-       case AV_PIX_FMT_YUV411P:
-       case AV_PIX_FMT_YUVJ420P:
-       case AV_PIX_FMT_YUVJ422P:
-       case AV_PIX_FMT_YUVJ444P:
-       case AV_PIX_FMT_RGB24:
-       case AV_PIX_FMT_ARGB:
-       case AV_PIX_FMT_RGBA:
-       case AV_PIX_FMT_ABGR:
-       case AV_PIX_FMT_BGRA:
-       case AV_PIX_FMT_RGB555LE:
-               /* 8-bit */
-               for (int c = 0; c < 3; ++c) {
+       {
+               /* Y */
+               uint8_t* p = data()[0];
+               int const lines = sample_size(0).height;
+               for (int y = 0; y < lines; ++y) {
+                       uint8_t* q = p;
+                       for (int x = 0; x < line_size()[0]; ++x) {
+                               *q = int(float(*q) * f);
+                               ++q;
+                       }
+                       p += stride()[0];
+               }
+
+               /* U, V */
+               for (int c = 1; c < 3; ++c) {
                        uint8_t* p = data()[c];
                        int const lines = sample_size(c).height;
                        for (int y = 0; y < lines; ++y) {
                                uint8_t* q = p;
                                for (int x = 0; x < line_size()[c]; ++x) {
-                                       *q = int (float (*q) * f);
+                                       *q = eight_bit_uv + int((int(*q) - eight_bit_uv) * f);
                                        ++q;
                                }
                                p += stride()[c];
                        }
                }
+
                break;
+       }
+
+       case AV_PIX_FMT_RGB24:
+       {
+               /* 8-bit */
+               uint8_t* p = data()[0];
+               int const lines = sample_size(0).height;
+               for (int y = 0; y < lines; ++y) {
+                       uint8_t* q = p;
+                       for (int x = 0; x < line_size()[0]; ++x) {
+                               *q = int (float (*q) * f);
+                               ++q;
+                       }
+                       p += stride()[0];
+               }
+               break;
+       }
 
-       case AV_PIX_FMT_YUV422P9LE:
-       case AV_PIX_FMT_YUV444P9LE:
-       case AV_PIX_FMT_YUV422P10LE:
-       case AV_PIX_FMT_YUV444P10LE:
-       case AV_PIX_FMT_YUV422P16LE:
-       case AV_PIX_FMT_YUV444P16LE:
-       case AV_PIX_FMT_YUVA420P9LE:
-       case AV_PIX_FMT_YUVA422P9LE:
-       case AV_PIX_FMT_YUVA444P9LE:
-       case AV_PIX_FMT_YUVA420P10LE:
-       case AV_PIX_FMT_YUVA422P10LE:
-       case AV_PIX_FMT_YUVA444P10LE:
-       case AV_PIX_FMT_RGB48LE:
        case AV_PIX_FMT_XYZ12LE:
+       case AV_PIX_FMT_RGB48LE:
                /* 16-bit little-endian */
                for (int c = 0; c < 3; ++c) {
                        int const stride_pixels = stride()[c] / 2;
@@ -1068,22 +1270,26 @@ Image::fade (float f)
                }
                break;
 
-       case AV_PIX_FMT_YUV422P9BE:
-       case AV_PIX_FMT_YUV444P9BE:
-       case AV_PIX_FMT_YUV444P10BE:
-       case AV_PIX_FMT_YUV422P10BE:
-       case AV_PIX_FMT_YUVA420P9BE:
-       case AV_PIX_FMT_YUVA422P9BE:
-       case AV_PIX_FMT_YUVA444P9BE:
-       case AV_PIX_FMT_YUVA420P10BE:
-       case AV_PIX_FMT_YUVA422P10BE:
-       case AV_PIX_FMT_YUVA444P10BE:
-       case AV_PIX_FMT_YUVA420P16BE:
-       case AV_PIX_FMT_YUVA422P16BE:
-       case AV_PIX_FMT_YUVA444P16BE:
-       case AV_PIX_FMT_RGB48BE:
-               /* 16-bit big-endian */
-               for (int c = 0; c < 3; ++c) {
+       case AV_PIX_FMT_YUV422P10LE:
+       {
+               /* Y */
+               {
+                       int const stride_pixels = stride()[0] / 2;
+                       int const line_size_pixels = line_size()[0] / 2;
+                       uint16_t* p = reinterpret_cast<uint16_t*> (data()[0]);
+                       int const lines = sample_size(0).height;
+                       for (int y = 0; y < lines; ++y) {
+                               uint16_t* q = p;
+                               for (int x = 0; x < line_size_pixels; ++x) {
+                                       *q = int(float(*q) * f);
+                                       ++q;
+                               }
+                               p += stride_pixels;
+                       }
+               }
+
+               /* U, V */
+               for (int c = 1; c < 3; ++c) {
                        int const stride_pixels = stride()[c] / 2;
                        int const line_size_pixels = line_size()[c] / 2;
                        uint16_t* p = reinterpret_cast<uint16_t*> (data()[c]);
@@ -1091,7 +1297,7 @@ Image::fade (float f)
                        for (int y = 0; y < lines; ++y) {
                                uint16_t* q = p;
                                for (int x = 0; x < line_size_pixels; ++x) {
-                                       *q = swap_16 (int (float (swap_16 (*q)) * f));
+                                       *q = ten_bit_uv + int((int(*q) - ten_bit_uv) * f);
                                        ++q;
                                }
                                p += stride_pixels;
@@ -1099,18 +1305,6 @@ Image::fade (float f)
                }
                break;
 
-       case AV_PIX_FMT_UYVY422:
-       {
-               int const Y = sample_size(0).height;
-               int const X = line_size()[0];
-               uint8_t* p = data()[0];
-               for (int y = 0; y < Y; ++y) {
-                       for (int x = 0; x < X; ++x) {
-                               *p = int (float (*p) * f);
-                               ++p;
-                       }
-               }
-               break;
        }
 
        default:
@@ -1118,14 +1312,14 @@ Image::fade (float f)
        }
 }
 
-shared_ptr<Image>
-Image::ensure_aligned (shared_ptr<Image> image)
+shared_ptr<const Image>
+Image::ensure_aligned (shared_ptr<const Image> image)
 {
        if (image->aligned()) {
                return image;
        }
 
-       return shared_ptr<Image> (new Image (image, true));
+       return make_shared<Image>(image, true);
 }
 
 size_t
@@ -1137,3 +1331,159 @@ Image::memory_used () const
        }
        return m;
 }
+
+class Memory
+{
+public:
+       Memory ()
+               : data(0)
+               , size(0)
+       {}
+
+       ~Memory ()
+       {
+               free (data);
+       }
+
+       uint8_t* data;
+       size_t size;
+};
+
+static void
+png_write_data (png_structp png_ptr, png_bytep data, png_size_t length)
+{
+       auto mem = reinterpret_cast<Memory*>(png_get_io_ptr(png_ptr));
+       size_t size = mem->size + length;
+
+       if (mem->data) {
+               mem->data = reinterpret_cast<uint8_t*>(realloc(mem->data, size));
+       } else {
+               mem->data = reinterpret_cast<uint8_t*>(malloc(size));
+       }
+
+       if (!mem->data) {
+               throw EncodeError (N_("could not allocate memory for PNG"));
+       }
+
+       memcpy (mem->data + mem->size, data, length);
+       mem->size += length;
+}
+
+static void
+png_flush (png_structp)
+{
+
+}
+
+static void
+png_error_fn (png_structp png_ptr, char const * message)
+{
+       reinterpret_cast<Image*>(png_get_error_ptr(png_ptr))->png_error (message);
+}
+
+void
+Image::png_error (char const * message)
+{
+       throw EncodeError (String::compose ("Error during PNG write: %1", message));
+}
+
+dcp::ArrayData
+Image::as_png () const
+{
+       DCPOMATIC_ASSERT (bytes_per_pixel(0) == 4);
+       DCPOMATIC_ASSERT (planes() == 1);
+       if (pixel_format() != AV_PIX_FMT_RGBA) {
+               return convert_pixel_format(dcp::YUVToRGB::REC709, AV_PIX_FMT_RGBA, true, false)->as_png();
+       }
+
+       /* error handling? */
+       png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, reinterpret_cast<void*>(const_cast<Image*>(this)), png_error_fn, 0);
+       if (!png_ptr) {
+               throw EncodeError (N_("could not create PNG write struct"));
+       }
+
+       Memory state;
+
+       png_set_write_fn (png_ptr, &state, png_write_data, png_flush);
+
+       png_infop info_ptr = png_create_info_struct(png_ptr);
+       if (!info_ptr) {
+               png_destroy_write_struct (&png_ptr, &info_ptr);
+               throw EncodeError (N_("could not create PNG info struct"));
+       }
+
+       png_set_IHDR (png_ptr, info_ptr, size().width, size().height, 8, PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+       png_byte ** row_pointers = reinterpret_cast<png_byte **>(png_malloc(png_ptr, size().height * sizeof(png_byte *)));
+       for (int i = 0; i < size().height; ++i) {
+               row_pointers[i] = (png_byte *) (data()[0] + i * stride()[0]);
+       }
+
+       png_write_info (png_ptr, info_ptr);
+       png_write_image (png_ptr, row_pointers);
+       png_write_end (png_ptr, info_ptr);
+
+       png_destroy_write_struct (&png_ptr, &info_ptr);
+       png_free (png_ptr, row_pointers);
+
+       return dcp::ArrayData (state.data, state.size);
+}
+
+
+void
+Image::video_range_to_full_range ()
+{
+       switch (_pixel_format) {
+       case AV_PIX_FMT_RGB24:
+       {
+               float const factor = 256.0 / 219.0;
+               uint8_t* p = data()[0];
+               int const lines = sample_size(0).height;
+               for (int y = 0; y < lines; ++y) {
+                       uint8_t* q = p;
+                       for (int x = 0; x < line_size()[0]; ++x) {
+                               *q = clamp(lrintf((*q - 16) * factor), 0L, 255L);
+                               ++q;
+                       }
+                       p += stride()[0];
+               }
+               break;
+       }
+       case AV_PIX_FMT_RGB48LE:
+       {
+               float const factor = 65536.0 / 56064.0;
+               uint16_t* p = reinterpret_cast<uint16_t*>(data()[0]);
+               int const lines = sample_size(0).height;
+               for (int y = 0; y < lines; ++y) {
+                       uint16_t* q = p;
+                       int const line_size_pixels = line_size()[0] / 2;
+                       for (int x = 0; x < line_size_pixels; ++x) {
+                               *q = clamp(lrintf((*q - 4096) * factor), 0L, 65535L);
+                               ++q;
+                       }
+                       p += stride()[0] / 2;
+               }
+               break;
+       }
+       case AV_PIX_FMT_GBRP12LE:
+       {
+               float const factor = 4096.0 / 3504.0;
+               for (int c = 0; c < 3; ++c) {
+                       uint16_t* p = reinterpret_cast<uint16_t*>(data()[c]);
+                       int const lines = sample_size(c).height;
+                       for (int y = 0; y < lines; ++y) {
+                               uint16_t* q = p;
+                               int const line_size_pixels = line_size()[c] / 2;
+                               for (int x = 0; x < line_size_pixels; ++x) {
+                                       *q = clamp(lrintf((*q - 256) * factor), 0L, 4095L);
+                                       ++q;
+                               }
+                       }
+               }
+               break;
+       }
+       default:
+               throw PixelFormatError ("video_range_to_full_range()", _pixel_format);
+       }
+}
+