From a861023c28159c363d49dce4f79a92debdc4241e Mon Sep 17 00:00:00 2001
From: "Simon A. Eugster" <simon.eu@gmail.com>
Date: Sat, 11 Feb 2012 16:08:38 +0100
Subject: [PATCH] Audio alignment: Attempts to get familiar with mlt

---
 CMakeLists.txt              |   1 +
 testingArea/CMakeLists.txt  |  15 ++++++
 testingArea/audioOffset.cpp | 100 ++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 testingArea/CMakeLists.txt
 create mode 100644 testingArea/audioOffset.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 45aeff18..d2a161b4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -88,6 +88,7 @@ add_subdirectory(renderer)
 add_subdirectory(src)
 add_subdirectory(thumbnailer)
 add_subdirectory(titles)
+add_subdirectory(testingArea)
 
 macro_display_feature_log()
 
diff --git a/testingArea/CMakeLists.txt b/testingArea/CMakeLists.txt
new file mode 100644
index 00000000..1b863b16
--- /dev/null
+++ b/testingArea/CMakeLists.txt
@@ -0,0 +1,15 @@
+
+message(STATUS "Building experimental executables")
+
+include_directories(
+  ${LIBMLT_INCLUDE_DIR}
+  ${LIBMLTPLUS_INCLUDE_DIR}
+)
+include(${QT_USE_FILE})
+
+add_executable(audioOffset audioOffset.cpp)
+target_link_libraries(audioOffset 
+  ${QT_LIBRARIES}
+  ${LIBMLT_LIBRARY}
+  ${LIBMLTPLUS_LIBRARY}
+)
diff --git a/testingArea/audioOffset.cpp b/testingArea/audioOffset.cpp
new file mode 100644
index 00000000..6e9a0b55
--- /dev/null
+++ b/testingArea/audioOffset.cpp
@@ -0,0 +1,100 @@
+
+#include <QFile>
+#include <mlt++/Mlt.h>
+#include <iostream>
+#include <cstdlib>
+
+int main(int argc, char *argv[])
+{
+    char *fileMain;
+    char *fileSub;
+    if (argc > 2) {
+        fileMain = argv[1];
+        fileSub = argv[2];
+    } else {
+        std::cout << "Usage: " << argv[0] << " <main audio file> <second audio file>" << std::endl;
+        return 0;
+    }
+    std::cout << "Trying to align (1)\n\t" << fileSub << "\nto fit on (2)\n\t" << fileMain
+              << "\n, result will indicate by how much (1) has to be moved." << std::endl;
+
+
+    // Initialize MLT
+    Mlt::Factory::init(NULL);
+
+    // Load an arbitrary profile
+    Mlt::Profile prof("hdv_1080_25p");
+
+
+    std::cout << "MLT initialized, profile loaded. Loading clips ..." << std::endl;
+
+
+    Mlt::Producer producer(prof, fileMain);
+    if (!producer.is_valid()) {
+        std::cout << fileMain << " is invalid." << std::endl;
+        return 2;
+    }
+    std::cout << "Successfully loaded producer " << fileMain << std::endl;
+    std::cout << "Some data: " << std::endl
+              << "Length: " << producer.get_length() << std::endl
+              << "fps: " << producer.get_fps() << std::endl;
+
+    int nSamples = 50;
+    Mlt::Frame *frame = producer.get_frame();
+    float *data = frame->get_audio(mlt_audio_float, 24000, 1, nSamples);
+
+    for (int i = 0; i < nSamples; i++) {
+        std::cout << " " << data[i];
+    }
+    std::cout << std::endl;
+
+/*
+    producer.set("video_index", "-1");
+
+    if (KdenliveSettings::normaliseaudiothumbs()) {
+        Mlt::Filter m_convert(prof, "volume");
+        m_convert.set("gain", "normalise");
+        producer.attach(m_convert);
+    }
+
+    int last_val = 0;
+    int val = 0;
+    double framesPerSecond = mlt_producer_get_fps(producer.get_producer());
+    Mlt::Frame *mlt_frame;
+
+    for (int z = (int) frame; z < (int)(frame + lengthInFrames) && producer.is_valid() &&  !m_abortAudioThumb; z++) {
+        val = (int)((z - frame) / (frame + lengthInFrames) * 100.0);
+        if (last_val != val && val > 1) {
+            setThumbsProgress(i18n("Creating audio thumbnail for %1", url.fileName()), val);
+            last_val = val;
+        }
+        producer.seek(z);
+        mlt_frame = producer.get_frame();
+        if (mlt_frame && mlt_frame->is_valid()) {
+            int samples = mlt_sample_calculator(framesPerSecond, frequency, mlt_frame_get_position(mlt_frame->get_frame()));
+            qint16* pcm = static_cast<qint16*>(mlt_frame->get_audio(audioFormat, frequency, channels, samples));
+            for (int c = 0; c < channels; c++) {
+                QByteArray audioArray;
+                audioArray.resize(arrayWidth);
+                for (int i = 0; i < audioArray.size(); i++) {
+                    audioArray[i] = ((*(pcm + c + i * samples / audioArray.size())) >> 9) + 127 / 2 ;
+                }
+                f.write(audioArray);
+                storeIn[z][c] = audioArray;
+            }
+        } else {
+            f.write(QByteArray(arrayWidth, '\x00'));
+        }
+        delete mlt_frame;
+    }
+    f.close();
+    setThumbsProgress(i18n("Creating audio thumbnail for %1", url.fileName()), -1);
+    if (m_abortAudioThumb) {
+        f.remove();
+    } else {
+        clip->updateAudioThumbnail(storeIn);
+    }*/
+
+    return 0;
+
+}
-- 
2.39.2