feat: Add streaming handlers for live TV proxying and VOD HLS transcoding using FFmpeg.

windows/flutter/ephemeral/cpp_client_wrapper/byte_buffer_streams.h

@@ -0,0 +1,102 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_
+
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <iostream>
+#include <vector>
+
+#include "include/flutter/byte_streams.h"
+
+namespace flutter {
+
+// Implementation of ByteStreamReader base on a byte array.
+class ByteBufferStreamReader : public ByteStreamReader {
+ public:
+  // Createa a reader reading from |bytes|, which must have a length of |size|.
+  // |bytes| must remain valid for the lifetime of this object.
+  explicit ByteBufferStreamReader(const uint8_t* bytes, size_t size)
+      : bytes_(bytes), size_(size) {}
+
+  virtual ~ByteBufferStreamReader() = default;
+
+  // |ByteStreamReader|
+  uint8_t ReadByte() override {
+    if (location_ >= size_) {
+      std::cerr << "Invalid read in StandardCodecByteStreamReader" << std::endl;
+      return 0;
+    }
+    return bytes_[location_++];
+  }
+
+  // |ByteStreamReader|
+  void ReadBytes(uint8_t* buffer, size_t length) override {
+    if (location_ + length > size_) {
+      std::cerr << "Invalid read in StandardCodecByteStreamReader" << std::endl;
+      return;
+    }
+    std::memcpy(buffer, &bytes_[location_], length);
+    location_ += length;
+  }
+
+  // |ByteStreamReader|
+  void ReadAlignment(uint8_t alignment) override {
+    uint8_t mod = location_ % alignment;
+    if (mod) {
+      location_ += alignment - mod;
+    }
+  }
+
+ private:
+  // The buffer to read from.
+  const uint8_t* bytes_;
+  // The total size of the buffer.
+  size_t size_;
+  // The current read location.
+  size_t location_ = 0;
+};
+
+// Implementation of ByteStreamWriter based on a byte array.
+class ByteBufferStreamWriter : public ByteStreamWriter {
+ public:
+  // Creates a writer that writes into |buffer|.
+  // |buffer| must remain valid for the lifetime of this object.
+  explicit ByteBufferStreamWriter(std::vector<uint8_t>* buffer)
+      : bytes_(buffer) {
+    assert(buffer);
+  }
+
+  virtual ~ByteBufferStreamWriter() = default;
+
+  // |ByteStreamWriter|
+  void WriteByte(uint8_t byte) { bytes_->push_back(byte); }
+
+  // |ByteStreamWriter|
+  void WriteBytes(const uint8_t* bytes, size_t length) {
+    assert(length > 0);
+    bytes_->insert(bytes_->end(), bytes, bytes + length);
+  }
+
+  // |ByteStreamWriter|
+  void WriteAlignment(uint8_t alignment) {
+    uint8_t mod = bytes_->size() % alignment;
+    if (mod) {
+      for (int i = 0; i < alignment - mod; ++i) {
+        WriteByte(0);
+      }
+    }
+  }
+
+ private:
+  // The buffer to write to.
+  std::vector<uint8_t>* bytes_;
+};
+
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CLIENT_WRAPPER_BYTE_BUFFER_STREAMS_H_