Implement IOCtx.

CMakeLists.txt

@@ -31,6 +31,7 @@ ExternalProject_Add(
                                              --disable-ffmpeg --disable-ffprobe --disable-ffplay --prefix=${PROJECT_SOURCE_DIR}/lib/
     BUILD_COMMAND make -j
     INSTALL_COMMAND make install
+    UPDATE_COMMAND  ""
 )
 
 set(SRC ${ROOT}/src)

src/ioctx.cc

+#include "ioctx.h"
+
+namespace IOCtx {
+
+///////////////////////////////////////////////////////////////////////////////
+//                                   InCtx                                   //
+///////////////////////////////////////////////////////////////////////////////
+
+InCtx::InCtx(std::string path, CustomProto proto):
+    fmt(nullptr) {
+
+    // Build AVIOContex for custom proto
+    AVIOContext *customIO = nullptr;
+
+    fmt = Utils::makeInAVFormat(path, customIO);
+}
+
+void InCtx::readFrame(AVPacket *packet) {
+    if (av_read_frame(fmt.get(), packet) < 0)
+        throw IO_ERROR();
+}
+
+bool InCtx::isReady() noexcept {
+    return fmt.get() != nullptr;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+//                                   OutCtx                                  //
+///////////////////////////////////////////////////////////////////////////////
+
+OutCtx::OutCtx(std::string path, CustomProto proto):
+    fmt(nullptr) {
+
+}
+
+}

src/ioctx.h

+#include <string>
+#include <stdexcept>
+#include "utils.h"
+
+extern "C" {
+    #include <libavformat/avformat.h>
+}
+
+
+#ifndef IOCTX_H
+#define IOCTX_H
+
+namespace IOCtx {
+
+// Forward Declarations
+class InCtx;
+class OutCtx;
+
+// Extra support custom protos
+enum CustomProto {
+    SHARED_MEMORY
+};
+
+class END_OF_FILE: public std::runtime_error {
+public:
+    END_OF_FILE(): std::runtime_error("") {}
+};
+
+class IO_ERROR: public std::runtime_error {
+public:
+    IO_ERROR(): std::runtime_error("") {}
+};
+
+
+class InCtx {
+    // OutCtx require parameters of InCtx
+    // to initialize.
+    friend OutCtx;
+public:
+    InCtx(std::string path):
+        fmt(Utils::makeInAVFormat(path, nullptr)) {}
+    InCtx(std::string path, CustomProto proto);
+
+    void readFrame(AVPacket*);
+    bool isReady() noexcept;
+
+private:
+    Utils::AVFormatContextShared fmt;
+};
+
+
+class OutCtx {
+public:
+    OutCtx(std::string path):
+        fmt(Utils::makeOutAVFormat(path, nullptr)) {}
+    OutCtx(std::string path, CustomProto proto);
+
+    void writeFrame(AVPacket*);
+    bool isReady() noexcept;
+private:
+    Utils::AVFormatContextShared fmt;
+};
+
+}
+
+#endif /* IOCTX_H */

src/utils.cc

+#include "utils.h"
+
+namespace Utils {
+
+static AVFormatContext* AVFormatInputContextConstructor(
+    std::string path, AVIOContext *customIO) {
+
+    AVFormatContext *ctx = customIO == nullptr ? nullptr : avformat_alloc_context();
+    ctx->pb = customIO;
+
+    if (avformat_open_input(&ctx, path.c_str(), nullptr, nullptr) < 0) {
+        return nullptr;
+    }
+    if (avformat_find_stream_info(ctx, nullptr) < 0) {
+        avformat_close_input(&ctx);
+        return nullptr;
+    }
+
+    return ctx;
+}
+
+static void AVFormatInputContextDestructor(AVFormatContext *ctx) {
+    avformat_close_input(&ctx);
+}
+
+AVFormatContextShared makeInAVFormat(std::string path, AVIOContext *customIO) {
+    AVFormatContextShared ioCtx {
+        AVFormatInputContextConstructor(path, customIO),
+        AVFormatInputContextDestructor
+    };
+
+    return ioCtx;
+}
+
+static AVFormatContext* AVFormatOutputContextConstructor(
+    std::string path, AVIOContext *customIO) {
+
+    AVFormatContext *ctx = customIO == nullptr ? nullptr : avformat_alloc_context();
+    ctx->pb = customIO;
+
+    if (avformat_open_input(&ctx, path.c_str(), nullptr, nullptr) < 0) {
+        return nullptr;
+    }
+
+    return ctx;
+}
+
+static void AVFormatOutputContextDestructor(AVFormatContext *ctx) {
+    avformat_close_input(&ctx);
+}
+
+AVFormatContextShared makeOutAVFormat(std::string path, AVIOContext *customIO) {
+    AVFormatContextShared ioCtx {
+        AVFormatOutputContextConstructor(path, customIO),
+        AVFormatOutputContextDestructor
+    };
+
+    return ioCtx;
+}
+
+}

src/utils.h

+#include <string>
+#include <memory>
+
+extern "C" {
+    #include <libavformat/avformat.h>
+}
+
+#ifndef UTILS_H
+#define UTILS_H
+
+namespace Utils {
+
+using AVFormatContextShared = std::shared_ptr<AVFormatContext>;
+AVFormatContextShared makeInAVFormat(std::string, AVIOContext*);
+AVFormatContextShared makeOutAVFormat(std::string, AVIOContext*);
+
+/* To check that is video specified by path valid
+ *
+ * This function require that ffmpeg is installed on
+ * running envrionment */
+bool isVideoValid(std::string path);
+
+}
+
+#endif /* UTILS_H */

tests/ioctxTestCases.cc

+#include <gtest/gtest.h>
+#include <string>
+#include "ioctx.h"
+#include "utils.h"
+
+extern "C" {
+    #include <libavformat/avformat.h>
+}
+
+
+class IOCTX_With_Default_Proto_Fixture: public ::testing::Test {
+protected:
+    void SetUp() override {
+        oCtx = OutCtx(outFilePath, iCtx);
+    }
+
+    std::string inFilePath = "./resources/sample.mp4";
+    std::string outFilePath = "./resources/sample_out.mp4";
+
+    InCtx iCtx { inFilePath };
+    OutCtx oCtx;
+};
+
+class IOCTX_With_SharedMemory_Proto_Fixture: public ::testing::Test {
+protected:
+    void SetUp() override {
+
+    }
+
+    InCtx iCtx;
+    OutCtx oCtx;
+};
+
+TEST_F(IOCTX_With_Default_Proto_Fixture, Description) {
+    AVPacket packet;
+
+    iCtx.readFrame(&packet);
+    oCtx.writeFrame(&packet);
+
+    ASSERT_TRUE(Utils::isVideoValid(outFilePath));
+}