evc: add decoder

libheif/CMakeLists.txt

@@ -89,6 +89,8 @@ set(libheif_sources
         codecs/avc_dec.cc
         codecs/evc_boxes.cc
         codecs/evc_boxes.h
+        codecs/evc_dec.h
+        codecs/evc_dec.cc
         image-items/mask_image.h
         image-items/mask_image.cc
         image-items/image_item.h

libheif/codecs/decoder.cc

@@ -39,7 +39,8 @@
 #include "jpeg_boxes.h"
 #include "jpeg2000_boxes.h"
 #include "codecs/uncompressed/unc_dec.h"
-
+#include "codecs/evc_dec.h"
+#include "evc_boxes.h"
 
 void DataExtent::set_from_image_item(std::shared_ptr<HeifFile> file, heif_item_id item)
 {
@@ -132,6 +133,10 @@ std::shared_ptr<Decoder> Decoder::alloc_for_infe_type(const HeifContext* ctx, he
       return std::make_shared<Decoder_uncompressed>(uncC,cmpd);
     }
 #endif
+    case fourcc("evc1"): {
+      auto evcC = ctx->get_heif_file()->get_property<Box_evcC>(id);
+      return std::make_shared<Decoder_EVC>(evcC);
+    }
     case fourcc("mski"): {
       return nullptr; // do we need a decoder for this?
     }

libheif/codecs/evc_boxes.cc

@@ -123,13 +123,13 @@ std::string Box_evcC::get_chroma_format_as_text() const
 {
   switch (m_configuration.chroma_format_idc)
   {
-  case 0:
+  case CHROMA_FORMAT_MONOCHROME:
     return std::string("Monochrome");
-  case 1:
+  case CHROMA_FORMAT_420:
     return std::string("4:2:0");
-  case 2:
+  case CHROMA_FORMAT_422:
     return std::string("4:2:2");
-  case 3:
+  case CHROMA_FORMAT_444:
     return std::string("4:4:4");
   default:
     return std::string("Invalid");
@@ -169,3 +169,16 @@ Error Box_evcC::write(StreamWriter& writer) const
 
   return Error::Ok;
 }
+
+void Box_evcC::get_header_nals(std::vector<uint8_t>& data) const
+{
+  for (const auto& array : m_nal_array) {
+    for (const auto& nalu : array.nal_units) {
+      data.push_back((nalu.size() >> 24) & 0xFF);
+      data.push_back((nalu.size() >> 16) & 0xFF);
+      data.push_back((nalu.size() >> 8) & 0xFF);
+      data.push_back((nalu.size() >> 0) & 0xFF);
+      data.insert(data.end(), nalu.begin(), nalu.end());
+    }
+  }
+}

libheif/codecs/evc_boxes.h

@@ -26,15 +26,17 @@
 #include <string>
 #include <vector>
 
-// #include "image-items/image_item.h"
-
-
 class Box_evcC : public Box {
 public:
   Box_evcC() { set_short_type(fourcc("evcC")); }
 
   bool is_essential() const override { return true; }
 
+  static const uint8_t CHROMA_FORMAT_MONOCHROME = 0;
+  static const uint8_t CHROMA_FORMAT_420 = 1;
+  static const uint8_t CHROMA_FORMAT_422 = 2;
+  static const uint8_t CHROMA_FORMAT_444 = 3;
+
   struct configuration {
     uint8_t configurationVersion = 1;
     uint8_t profile_idc;
@@ -63,6 +65,8 @@ class Box_evcC : public Box {
 
   Error write(StreamWriter &writer) const override;
 
+  void get_header_nals(std::vector<uint8_t>& data) const;
+
 protected:
   Error parse(BitstreamRange &range, const heif_security_limits* limits) override;
 

libheif/codecs/evc_dec.cc

@@ -0,0 +1,74 @@
+/*
+ * HEIF codec.
+ * Copyright (c) 2024 Dirk Farin <[email protected]>
+ *
+ * This file is part of libheif.
+ *
+ * libheif is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * libheif 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libheif.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "evc_dec.h"
+#include "evc_boxes.h"
+#include "error.h"
+#include "context.h"
+
+#include <string>
+
+
+Result<std::vector<uint8_t>> Decoder_EVC::read_bitstream_configuration_data() const
+{
+  std::vector<uint8_t> data;
+  m_evcC->get_header_nals(data);
+  return data;
+}
+
+
+int Decoder_EVC::get_luma_bits_per_pixel() const
+{
+  return m_evcC->get_configuration().bit_depth_luma;
+}
+
+
+int Decoder_EVC::get_chroma_bits_per_pixel() const
+{
+  return m_evcC->get_configuration().bit_depth_chroma;
+}
+
+
+Error Decoder_EVC::get_coded_image_colorspace(heif_colorspace* out_colorspace, heif_chroma* out_chroma) const
+{
+  switch (m_evcC->get_configuration().chroma_format_idc) {
+    case Box_evcC::CHROMA_FORMAT_MONOCHROME:
+      *out_chroma = heif_chroma_monochrome;
+      *out_colorspace = heif_colorspace_monochrome;
+      return Error::Ok;
+    case Box_evcC::CHROMA_FORMAT_420:
+      *out_chroma = heif_chroma_420;
+      *out_colorspace = heif_colorspace_YCbCr;
+      return Error::Ok;
+    case Box_evcC::CHROMA_FORMAT_422:
+      *out_chroma = heif_chroma_422;
+      *out_colorspace = heif_colorspace_YCbCr;
+      return Error::Ok;
+    case Box_evcC::CHROMA_FORMAT_444:
+      *out_chroma = heif_chroma_444;
+      *out_colorspace = heif_colorspace_YCbCr;
+      return Error::Ok;
+    default:
+      *out_chroma = heif_chroma_undefined;
+      *out_colorspace = heif_colorspace_undefined;
+      return Error{heif_error_Invalid_input, heif_suberror_Decompression_invalid_data, "unsupported (impossible?) EVC chroma value"};
+    }
+}
+

libheif/codecs/evc_dec.h

@@ -0,0 +1,53 @@
+/*
+ * HEIF codec.
+ * Copyright (c) 2024 Dirk Farin <[email protected]>
+ *
+ * This file is part of libheif.
+ *
+ * libheif is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * libheif 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libheif.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef HEIF_EVC_DEC_H
+#define HEIF_EVC_DEC_H
+
+#include "libheif/heif.h"
+#include "error.h"
+
+#include <memory>
+#include <vector>
+#include <codecs/decoder.h>
+
+class Box_evcC;
+
+
+class Decoder_EVC : public Decoder
+{
+public:
+  explicit Decoder_EVC(const std::shared_ptr<const Box_evcC>& evcC) : m_evcC(evcC) {}
+
+  heif_compression_format get_compression_format() const override { return heif_compression_EVC; }
+
+  int get_luma_bits_per_pixel() const override;
+
+  int get_chroma_bits_per_pixel() const override;
+
+  Error get_coded_image_colorspace(heif_colorspace*, heif_chroma*) const override;
+
+  Result<std::vector<uint8_t>> read_bitstream_configuration_data() const override;
+
+private:
+  const std::shared_ptr<const Box_evcC> m_evcC;
+};
+
+#endif