Merge branch 'master' of https://github.com/Raveler/ffmpeg-cpp

Author: Raveler

.gitignore

@@ -18,7 +18,7 @@
 /source/ffmpeg-cpp/encode_audio/obj
 /source/ffmpeg-cpp/encode_video/obj
 /source/ffmpeg-cpp/decode_video/obj
-/source/ffmpeg-cpp/filter_video/obj
+/source/ffmpeg-cpp/filtering_video/obj
 /include
 
 /source/ffmpeg-cpp/remuxing/obj

README.md

@@ -1,2 +1,74 @@
 # ffmpeg-cpp
-A clean C++ wrapper around the ffmpeg libraries
+A clean C++ wrapper around the ffmpeg libraries. Makes the most commonly used functionality of FFmpeg easily available for any C++ projects with an easy-to-use interface. The full power of FFmpeg compacted in 10 lines of C++ code: if this sounds useful to you, read on!
+
+# Installation
+
+## Windows
+
+1. Clone the repository
+2. Download a build of FFmpeg from https://ffmpeg.zeranoe.com/builds/. The project was last tested with **4.1**. You will need both the dev version (for .h and .lib files) and the shared version (for .dll). Extract all of them into the ffmpeg directory in the repository. there are more instructions on how to extract them properly in the ffmpeg/readme.txt file.
+3. Open the Visual Studio solution in the source directory.
+4. Build everything.
+
+This will build a .lib file that you can use in your own C++ projects. It will also generate an include-folder in the repo root that you can add to your include filders in your own project.
+
+## Linux
+
+Currently, only a Windows environment with Visual Studio is supported. This is simply because I do not have experience with cmake and Linux-projects, since the project itself is fully platform-independent. If anyone is willing to help me out with configuring cmake, please get in touch!
+
+# Usage
+
+There are multiple demo projects included in the solution. Check out the demo-project for a thorough exploration of the features (demuxing, decoding, filtering, encoding, muxing) or one of the other examples for a simpler example to follow.
+
+To give you an idea, this code will load a video stream from a container, filter it, and write it back out to another container:
+
+```C++
+// Create a muxer that will output the video as MP4.
+Muxer* muxer = new Muxer("filtered_video.mp4");
+
+// Create a MPEG2 codec that will encode the raw data.
+VideoCodec* codec = new VideoCodec(AV_CODEC_ID_MPEG2VIDEO);
+
+// Create an encoder that will encode the raw audio data using the codec specified above.
+// Tie it to the muxer so it will be written to file.
+VideoEncoder* encoder = new VideoEncoder(codec, muxer);
+
+// Create a video filter and do some funny stuff with the video data.
+VideoFilter* filter = new VideoFilter("scale=640:150,transpose=cclock,vignette", encoder);
+
+// Load a container. Pick the best video stream container in the container
+// And send it to the filter.
+Demuxer* demuxer = new Demuxer("big_buck_bunny.mp4");
+demuxer->DecodeBestVideoStream(filter);
+
+// Prepare the output pipeline.
+// This will decode a small amount of frames so the pipeline can configure itself.
+demuxer->PreparePipeline();
+
+// Push all the remaining frames through.
+while (!demuxer->IsDone())
+{
+	demuxer->Step();
+}
+		
+// Save everything to disk by closing the muxer.
+muxer->Close();
+
+```
+
+# Why?
+
+I developed this project to be able to to integrate FFmpeg into our program without having to call the executable to do an operation. This is important because starting up an external executable tends to be blocked by antivirus software and can cause issues with users. It has been tested for the most common functionality, and some of the examples from https://github.com/FFmpeg/FFmpeg/tree/master/doc/examples are mirrored in the project as well.
+
+# Roadmap
+
+- Add Linux/Mac build support
+- Audio filtering
+- Adding proper unit tests
+- Testing with more codecs, containers
+
+# License
+
+This library is licensed under LGPL (https://en.wikipedia.org/wiki/GNU_Lesser_General_Public_License).
+
+Please note though that FFmpeg, which you will need to build this library, is not. Depending on how you build it, it is either LGPL or GPL. So once you use the LGPL-version of FFmpeg in your project, this library will be GPL too.

ffmpeg/readme.txt

@@ -3,6 +3,7 @@ In this folder, you need to put your ffmpeg binaries, library files and includes
 The structure should be as follows:
 /include contains all header files for the ffmpeg project
 /lib contains all .lib files
+/bin contains all .dll files
 
 For Windows, you can get the necessary files from:
 https://www.ffmpeg.org/download.html

source/ffmpeg-cpp/demo/demo.vcxproj.user

@@ -1,13 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
-    <LocalDebuggerCommandArguments>"D:\WonderMedia\ffmpeg\samples\carphone_qcif.y4m" "D:\WonderMedia\ffmpeg\samples\DesiJourney.wav" "D:\WonderMedia\ffmpeg\samples\out.mp4"</LocalDebuggerCommandArguments>
-    <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
-    <LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
-  </PropertyGroup>
-  <PropertyGroup>
-    <ShowAllFiles>false</ShowAllFiles>
-  </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
@@ -16,6 +8,10 @@
     <LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
   </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
+    <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>
+  </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <LocalDebuggerWorkingDirectory>$(OutDir)</LocalDebuggerWorkingDirectory>
     <DebuggerFlavor>WindowsLocalDebugger</DebuggerFlavor>

source/ffmpeg-cpp/encode_video/encode_video.cpp

@@ -14,10 +14,12 @@ int main()
 		// Create a muxer that will output the video as MKV.
 		Muxer* muxer = new Muxer("output.mpg");
 
-		// Create a MP3 codec that will encode the raw data.
+		// Create a MPEG2 codec that will encode the raw data.
 		VideoCodec* codec = new VideoCodec("mpeg2video");
-		//codec->SetOption("preset", "default");
-		//VideoCodec* codec = new H264NVEncCodec();
+
+		// Set the global quality of the video encoding. This maps to the command line
+		// parameter -qscale and must be within range [0,31].
+		codec->SetQualityScale(0);
 
 		// Create an encoder that will encode the raw audio data as MP3.
 		// Tie it to the muxer so it will be written to the file.
@@ -41,16 +43,12 @@ int main()
 		// Save everything to disk by closing the muxer.
 		muxer->Close();
 	}
-	catch (const char* bla)
-	{
-
-	}
-	/*catch (FFmpegException e)
+	catch (FFmpegException e)
 	{
 		cerr << "Exception caught!" << endl;
 		cerr << e.what() << endl;
 		throw e;
-	}*/
+	}
 
 	cout << "Encoding complete!" << endl;
 	cout << "Press any key to continue..." << endl;

source/ffmpeg-cpp/ffmpeg-cpp/Codecs/VideoCodec.cpp

@@ -19,6 +19,13 @@ namespace ffmpegcpp
 	{
 	}
 
+	void VideoCodec::SetQualityScale(int qscale)
+	{
+
+		codecContext->flags |= AV_CODEC_FLAG_QSCALE;
+		codecContext->global_quality = FF_QP2LAMBDA * 0;
+	}
+
 	bool VideoCodec::IsPixelFormatSupported(AVPixelFormat format)
 	{
 		if (format == AV_PIX_FMT_NONE) return true; // let the codec deal with this
@@ -77,4 +84,37 @@ namespace ffmpegcpp
 		if (*p == AV_PIX_FMT_NONE) throw FFmpegException("Codec " + string(codecContext->codec->name) + " does not have a default pixel format, you have to specify one");
 		return *p;
 	}
+
+	AVRational VideoCodec::GetClosestSupportedFrameRate(AVRational originalFrameRate)
+	{
+		if (!codecContext->codec->supported_framerates)
+		{
+			// make up a frame rate - there is no supported frame rate
+			return originalFrameRate;
+		};
+
+		const AVRational *p = codecContext->codec->supported_framerates;
+		AVRational bestFrameRate;
+		bestFrameRate.num = 0;
+		bestFrameRate.den = 1;
+		double bestDiff = std::numeric_limits<double>::max();
+		double fVal = av_q2d(originalFrameRate);
+		while (p->num)
+		{
+			double pVal = av_q2d(*p);
+			double diff = abs(pVal - fVal);
+			if (diff < bestDiff)
+			{
+				bestDiff = diff;
+				bestFrameRate.num = p->num;
+				bestFrameRate.den = p->den;
+			}
+			p++;
+		}
+
+		// There were no valid frame rates in the list... this should never happen unless ffmpeg screws up.
+		if (bestFrameRate.num == 0) return originalFrameRate;
+
+		return bestFrameRate;
+	}
 }

source/ffmpeg-cpp/ffmpeg-cpp/Codecs/VideoCodec.h

@@ -16,10 +16,14 @@ namespace ffmpegcpp
 
 		OpenCodec* Open(int width, int height, AVRational* frameRate, AVPixelFormat format);
 
+		// This maps to the qscale parameter so should be in the range [0,31].
+		void SetQualityScale(int qscale);
+
 		bool IsPixelFormatSupported(AVPixelFormat format);
 		bool IsFrameRateSupported(AVRational* frameRate);
 
 		AVPixelFormat GetDefaultPixelFormat();
+		AVRational GetClosestSupportedFrameRate(AVRational frameRate);
 
 	};
 

source/ffmpeg-cpp/ffmpeg-cpp/Frame Sinks/VideoEncoder.cpp

@@ -71,11 +71,18 @@ namespace ffmpegcpp
 		// configure the parameters for the codec based on the frame and our preferences
 		int width = frame->width;
 		int height = frame->height;
+
+		// the format is either the provided format, or the default format if it is not supported
 		AVPixelFormat format = finalPixelFormat;
+		if (!closedCodec->IsPixelFormatSupported(format)) format = closedCodec->GetDefaultPixelFormat();
 		if (format == AV_PIX_FMT_NONE) format = closedCodec->GetDefaultPixelFormat();
+
+		// the frame rate is either the input frame rate, OR the default frame rate if the input frame rate
+		// is not supported, OR the explicitly chosen framerate.
 		AVRational frameRate;
 		frameRate.num = timeBase->den;
 		frameRate.den = timeBase->num;
+		if (!closedCodec->IsFrameRateSupported(&frameRate)) frameRate = closedCodec->GetClosestSupportedFrameRate(frameRate);
 		if (finalFrameRateSet) frameRate = finalFrameRate;
 
 		// open the codec

source/ffmpeg-cpp/ffmpeg-cpp/Muxing/AudioOutputStream.cpp

@@ -37,6 +37,26 @@ namespace ffmpegcpp
 		}
 
 		codecTimeBase = openCodec->GetContext()->time_base;
+
+		// Copy side_data from the codec context to the stream... this is 
+		// necessary for certain codecs such as mpeg2video!
+		if (openCodec->GetContext()->nb_coded_side_data)
+		{
+			int i;
+
+			for (i = 0; i < openCodec->GetContext()->nb_coded_side_data; i++)
+			{
+				const AVPacketSideData *sd_src = &openCodec->GetContext()->coded_side_data[i];
+				uint8_t *dst_data;
+
+				dst_data = av_stream_new_side_data(stream, sd_src->type, sd_src->size);
+				if (!dst_data)
+				{
+					throw FFmpegException("Failed to allocate memory for new side_data");
+				}
+				memcpy(dst_data, sd_src->data, sd_src->size);
+			}
+		}
 	}
 
 	void AudioOutputStream::WritePacket(AVPacket *pkt, OpenCodec* openCodec)

source/ffmpeg-cpp/ffmpeg-cpp/Muxing/Muxer.cpp

@@ -17,8 +17,8 @@ namespace ffmpegcpp
 		avformat_alloc_output_context2(&containerContext, NULL, NULL, fileName);
 		if (!containerContext)
 		{
-			printf("WARNING: Could not deduce output format from file extension: using MPEG. as default\n");
-			avformat_alloc_output_context2(&containerContext, NULL, "mpeg", fileName);
+			printf("WARNING: Could not deduce output format from file extension: using MP4. as default\n");
+			avformat_alloc_output_context2(&containerContext, NULL, "mp4", fileName);
 		}
 		if (!containerContext)
 		{
@@ -38,6 +38,12 @@ namespace ffmpegcpp
 	{
 		if (containerContext != nullptr)
 		{
+			// if some of the output streams weren't primed, we cannot finish this process
+			if (!IsPrimed())
+			{
+				throw FFmpegException("You cannot close a muxer when one of the streams wasn't primed. You need to make sure all streams are primed before closing the muxer.");
+			}
+
 			/* Write the trailer, if any. The trailer must be written before you
 			* close the CodecContexts open when you wrote the header; otherwise
 			* av_write_trailer() may try to use memory that was freed on