1 files changed, 96 insertions, 0 deletions
diff --git a/examples/ivf_parser.cc b/examples/ivf_parser.cc
new file mode 100644
index 0000000..f8adb14
--- /dev/null
+++ b/examples/ivf_parser.cc
@@ -0,0 +1,96 @@
+// Copyright 2019 The libgav1 Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "examples/ivf_parser.h"
+
+#include <cstdio>
+#include <cstring>
+
+#include "examples/file_reader_constants.h"
+#include "examples/logging.h"
+
+namespace libgav1 {
+namespace {
+
+size_t ReadLittleEndian16(const uint8_t* const buffer) {
+  size_t value = buffer[1] << 8;
+  value |= buffer[0];
+  return value;
+}
+
+size_t ReadLittleEndian32(const uint8_t* const buffer) {
+  size_t value = buffer[3] << 24;
+  value |= buffer[2] << 16;
+  value |= buffer[1] << 8;
+  value |= buffer[0];
+  return value;
+}
+
+}  // namespace
+
+bool ParseIvfFileHeader(const uint8_t* const header_buffer,
+                        IvfFileHeader* const ivf_file_header) {
+  if (header_buffer == nullptr || ivf_file_header == nullptr) return false;
+
+  if (memcmp(kIvfSignature, header_buffer, 4) != 0) {
+    return false;
+  }
+
+  // Verify header version and length.
+  const size_t ivf_header_version = ReadLittleEndian16(&header_buffer[4]);
+  if (ivf_header_version != kIvfHeaderVersion) {
+    LIBGAV1_EXAMPLES_LOG_ERROR("Unexpected IVF version");
+  }
+
+  const size_t ivf_header_size = ReadLittleEndian16(&header_buffer[6]);
+  if (ivf_header_size != kIvfFileHeaderSize) {
+    LIBGAV1_EXAMPLES_LOG_ERROR("Invalid IVF file header size");
+    return false;
+  }
+
+  if (memcmp(kAv1FourCcLower, &header_buffer[8], 4) != 0 &&
+      memcmp(kAv1FourCcUpper, &header_buffer[8], 4) != 0) {
+    LIBGAV1_EXAMPLES_LOG_ERROR("Unsupported codec 4CC");
+    return false;
+  }
+
+  ivf_file_header->width = ReadLittleEndian16(&header_buffer[12]);
+  ivf_file_header->height = ReadLittleEndian16(&header_buffer[14]);
+  ivf_file_header->frame_rate_numerator =
+      ReadLittleEndian32(&header_buffer[16]);
+  ivf_file_header->frame_rate_denominator =
+      ReadLittleEndian32(&header_buffer[20]);
+
+  return true;
+}
+
+bool ParseIvfFrameHeader(const uint8_t* const header_buffer,
+                         IvfFrameHeader* const ivf_frame_header) {
+  if (header_buffer == nullptr || ivf_frame_header == nullptr) return false;
+
+  ivf_frame_header->frame_size = ReadLittleEndian32(header_buffer);
+  if (ivf_frame_header->frame_size > kMaxTemporalUnitSize) {
+    LIBGAV1_EXAMPLES_LOG_ERROR("Temporal Unit size exceeds maximum");
+    return false;
+  }
+
+  ivf_frame_header->timestamp = ReadLittleEndian32(&header_buffer[4]);
+  const uint64_t timestamp_hi =
+      static_cast<uint64_t>(ReadLittleEndian32(&header_buffer[8])) << 32;
+  ivf_frame_header->timestamp |= timestamp_hi;
+
+  return true;
+}
+
+}  // namespace libgav1