added some C++ wrappers

CMakeLists.txt

@@ -11,6 +11,6 @@ link_directories(${FFMPEG_LIBRARY_DIRS})
 
 #message(FATAL_ERROR ${FFMPEG_LIBRARIES})
 
-set(SOURCE_FILES main.cpp)
+set(SOURCE_FILES main.cpp ffcpp/MediaFile.cpp ffcpp/MediaFile.h ffcpp/ffcpp.cpp ffcpp/ffcpp.h ffcpp/Stream.cpp ffcpp/Stream.h ffcpp/Codec.cpp ffcpp/Codec.h)
 add_executable(ffConv ${SOURCE_FILES})
 target_link_libraries(ffConv ${FFMPEG_LIBRARIES})

ffcpp/Codec.cpp

@@ -0,0 +1,72 @@
+#include "Codec.h"
+#include "ffcpp.h"
+#include <stdexcept>
+
+namespace ffcpp {
+
+	Codec::Codec(): _codecCtx(nullptr), _codec(nullptr) {
+
+	}
+
+	Codec::Codec(AVCodecContext *ctx, CodecType type): _codecCtx(ctx) {
+		if(type == CodecType::Encoder) {
+			_codec = avcodec_find_encoder(ctx->codec_id);
+		} else {
+			_codec = avcodec_find_decoder(ctx->codec_id);
+		}
+
+		if(!_codec) throw std::runtime_error("cannot find codec");
+
+		int res = avcodec_open2(_codecCtx, _codec, nullptr);
+		throwIfError(res, "cannot open codec");
+	}
+
+	Codec::Codec(AVCodecContext *ctx, AVCodec *codec) {
+		_codecCtx = ctx;
+		_codec = codec;
+
+		int res = avcodec_open2(_codecCtx, _codec, nullptr);
+		throwIfError(res, "cannot open codec");
+	}
+
+	Codec::~Codec() {
+		//avcodec_close(_codecCtx);
+	}
+
+	Codec::operator AVCodecContext*() const {
+		return _codecCtx;
+	}
+
+	int Codec::width() const {
+		return _codecCtx->width;
+	}
+
+	int Codec::height() const {
+		return _codecCtx->height;
+	}
+
+	AVRational Codec::timeBase() const {
+		return _codecCtx->time_base;
+	}
+
+	int Codec::capabilities() const {
+		return _codec->capabilities;
+	}
+
+	AVPixelFormat Codec::pixelFormat() const {
+		return _codecCtx->pix_fmt;
+	}
+
+	void Codec::setWidth(int width) {
+		_codecCtx->width = width;
+	}
+
+	void Codec::setHeight(int height) {
+		_codecCtx->height = height;
+	}
+
+	void Codec::setPixelFormat(AVPixelFormat pixelFormat) {
+		_codecCtx->pix_fmt = pixelFormat;
+	}
+
+}

ffcpp/Codec.h

@@ -0,0 +1,41 @@
+#ifndef FFCONV_CODEC_H
+#define FFCONV_CODEC_H
+
+extern "C" {
+	#include <libavformat/avformat.h>
+}
+
+namespace ffcpp {
+
+	enum class CodecType {
+		Encoder,
+		Decoder
+	};
+
+	class Codec {
+	private:
+		AVCodecContext* _codecCtx;
+		AVCodec* _codec;
+
+	public:
+		Codec();
+		Codec(AVCodecContext* ctx, CodecType type);
+		Codec(AVCodecContext* ctx, AVCodec* codec);
+		~Codec();
+
+		operator AVCodecContext*() const;
+
+		int width() const;
+		int height() const;
+		AVRational timeBase() const;
+		int capabilities() const;
+		AVPixelFormat pixelFormat() const;
+
+		void setWidth(int width);
+		void setHeight(int height);
+		void setPixelFormat(AVPixelFormat pixelFormat);
+	};
+
+}
+
+#endif //FFCONV_CODEC_H

ffcpp/MediaFile.cpp

@@ -0,0 +1,107 @@
+#include "MediaFile.h"
+#include "ffcpp.h"
+#include <stdexcept>
+
+namespace ffcpp {
+
+	MediaFile::MediaFile(const std::string& src, Mode mode) {
+		_mode = mode;
+		if(mode == Mode::Read) {
+			int res = avformat_open_input(&_formatCtx, src.c_str(), nullptr, nullptr);
+			throwIfError(res, "cannot open input file");
+
+			res = avformat_find_stream_info(_formatCtx, nullptr);
+			throwIfError(res, "cannot find stream info");
+		} else if(mode == Mode::Write) {
+			int res = avformat_alloc_output_context2(&_formatCtx, nullptr, nullptr, src.c_str());
+			throwIfError(res, "cannot allocate format context");
+
+			if (!(_formatCtx->oformat->flags & AVFMT_NOFILE)) {
+				res = avio_open(&_formatCtx->pb, src.c_str(), AVIO_FLAG_WRITE);
+				throwIfError(res, "cannot init avio context");
+			}
+
+			if(_formatCtx->oformat->flags & AVFMT_GLOBALHEADER)
+				_formatCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
+
+			av_dump_format(_formatCtx, 0, src.c_str(), 1);
+		}
+	}
+
+	bool MediaFile::hasStream(AVMediaType type) const {
+		for(size_t i = 0; i < _formatCtx->nb_streams; ++i) {
+			if(_formatCtx->streams[i]->codec->codec_type == type) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	bool MediaFile::hasVideo() const {
+		return hasStream(AVMEDIA_TYPE_VIDEO);
+	}
+
+	bool MediaFile::hasAudio() const {
+		return hasStream(AVMEDIA_TYPE_AUDIO);
+	}
+
+	Stream MediaFile::getStream(AVMediaType type, size_t index) const {
+		for(size_t i = 0, curIndex = 0; i < _formatCtx->nb_streams; ++i) {
+			if(_formatCtx->streams[i]->codec->codec_type == type) {
+				if(curIndex == index) {
+					return Stream(_formatCtx->streams[i]);
+				} else {
+					curIndex++;
+				}
+			}
+		}
+
+		throw std::runtime_error("cannot find stream");
+	}
+
+	Stream MediaFile::videoStream(size_t index /* = 0 */) const {
+		return getStream(AVMEDIA_TYPE_VIDEO, index);
+	}
+
+	Stream MediaFile::audioStream(size_t index /* = 0 */) const {
+		return getStream(AVMEDIA_TYPE_AUDIO, index);
+	}
+
+	MediaFile::operator AVFormatContext*() const {
+		return _formatCtx;
+	}
+
+	MediaFile::~MediaFile() {
+		if(_mode == Mode::Write) {
+			avformat_free_context(_formatCtx);
+		} else {
+			avformat_close_input(&_formatCtx);
+		}
+	}
+
+	Stream MediaFile::addStream(AVCodecID codecID, int width, int height, AVPixelFormat pixelFormat) {
+		AVCodec* codec = avcodec_find_encoder(codecID);
+		if(!codec) throw std::runtime_error("cannot find codec");
+
+		AVStream* stream = avformat_new_stream(_formatCtx, codec);
+		if(!stream) throw  std::runtime_error("cannot create stream");
+
+		AVCodecContext* ctx = stream->codec;
+		ctx->width = width;
+		ctx->height = height;
+		ctx->pix_fmt = pixelFormat;
+
+		return Stream(stream, codec);
+	}
+
+	void MediaFile::writeHeader() {
+		int res = avformat_write_header(_formatCtx, nullptr);
+		throwIfError(res, "error writing header");
+	}
+
+	void MediaFile::writeTrailer() {
+		int res = av_write_trailer(_formatCtx);
+		throwIfError(res, "error writing trailer");
+	}
+}

ffcpp/MediaFile.h

@@ -0,0 +1,47 @@
+#ifndef FFCONV_MEDIAFILE_H
+#define FFCONV_MEDIAFILE_H
+
+#include "Stream.h"
+
+extern "C" {
+	#include <libavformat/avformat.h>
+}
+
+#include <string>
+
+namespace ffcpp {
+
+	enum class Mode {
+		Read,
+		Write
+	};
+
+	class MediaFile {
+	private:
+		AVFormatContext* _formatCtx;
+		Mode _mode;
+
+	public:
+		MediaFile(const std::string& src, Mode mode);
+
+		operator AVFormatContext*() const;
+
+		bool hasVideo() const;
+		bool hasAudio() const;
+		Stream videoStream(size_t index = 0) const;
+		Stream audioStream(size_t index = 0) const;
+		Stream addStream(AVCodecID codecID, int width, int height, AVPixelFormat pixelFormat);
+
+		void writeHeader();
+		void writeTrailer();
+
+		~MediaFile();
+
+	private:
+		bool hasStream(AVMediaType type) const;
+		Stream getStream(AVMediaType type, size_t index) const;
+	};
+
+}
+
+#endif //FFCONV_MEDIAFILE_H

ffcpp/Stream.cpp

@@ -0,0 +1,36 @@
+#include "Stream.h"
+#include <stdexcept>
+
+namespace ffcpp {
+
+	Stream::Stream() {
+		_stream = nullptr;
+	}
+
+	Stream::Stream(AVStream *stream) {
+		_stream = stream;
+		_codec = Codec(_stream->codec, CodecType::Decoder);
+	}
+
+	Stream::Stream(AVStream *stream, AVCodec* encoder) {
+		_stream = stream;
+		_codec = Codec(stream->codec, encoder);
+	}
+
+	Stream::operator AVStream*() const {
+		return _stream;
+	}
+
+	Codec Stream::codec() const {
+		return _codec;
+	}
+
+	AVRational Stream::timeBase() const {
+		return _stream->time_base;
+	}
+
+	void Stream::setTimeBase(AVRational timeBase) {
+		_stream->time_base = timeBase;
+	}
+
+}

ffcpp/Stream.h

@@ -0,0 +1,30 @@
+#ifndef FFCONV_STREAM_H
+#define FFCONV_STREAM_H
+
+#include "Codec.h"
+
+extern "C" {
+	#include <libavformat/avformat.h>
+}
+
+namespace ffcpp {
+
+	class Stream {
+	private:
+		AVStream* _stream;
+		Codec _codec;
+
+	public:
+		Stream();
+		Stream(AVStream* stream);
+		Stream(AVStream* stream, AVCodec* encoder);
+		operator AVStream*() const;
+		Codec codec() const;
+
+		AVRational timeBase() const;
+		void setTimeBase(AVRational timeBase);
+	};
+
+}
+
+#endif //FFCONV_STREAM_H

ffcpp/ffcpp.cpp

@@ -0,0 +1,22 @@
+#include "ffcpp.h"
+#include <stdexcept>
+
+extern "C" {
+	#include <libavformat/avformat.h>
+}
+
+namespace ffcpp {
+
+	void init() {
+		av_register_all();
+	}
+
+	void throwIfError(int result, const std::string& description) {
+		if(result < 0) {
+			char errStr[260];
+			av_strerror(result, errStr, 260);
+			throw std::runtime_error(description + ": " + errStr);
+		}
+	}
+
+}

ffcpp/ffcpp.h

@@ -0,0 +1,13 @@
+#ifndef FFCONV_FFCPP_H
+#define FFCONV_FFCPP_H
+
+#include <string>
+
+namespace ffcpp {
+
+	void init();
+	void throwIfError(int result, const std::string& description);
+
+}
+
+#endif //FFCONV_FFCPP_H

main.cpp

@@ -1,4 +1,8 @@
 #include <iostream>
+#include "ffcpp/ffcpp.h"
+#include "ffcpp/MediaFile.h"
+#include "ffcpp/Stream.h"
+#include "ffcpp/Codec.h"
 
 extern "C" {
 	#include <libavformat/avformat.h>
@@ -12,69 +16,23 @@ void checkResult(int res, const char* msg) {
 	}
 }
 
+namespace ff = ffcpp;
+
 int main(int argc, char** argv) {
-	AVFormatContext* inFmtCtx = nullptr;
-	AVFormatContext* outFmtCtx = nullptr;
+	ff::init();
+	ff::MediaFile input(argv[1], ff::Mode::Read);
+	ff::MediaFile output(argv[2], ff::Mode::Write);
 
-	av_register_all();
-	int res = avformat_open_input(&inFmtCtx, argv[1], nullptr, nullptr);
-	checkResult(res, "cannot open input");
-
-	res = avformat_find_stream_info(inFmtCtx, nullptr);
-	checkResult(res, "cannot find stream info");
-
-	res = avformat_alloc_output_context2(&outFmtCtx, nullptr, nullptr, argv[2]);
-	checkResult(res, "cannot allocate output context");
-
-	AVStream *videoStream = nullptr, *audioStream = nullptr;
-	for(int i = 0; i < inFmtCtx->nb_streams; ++i) {
-		AVStream* stream = inFmtCtx->streams[i];
-		if(stream->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
-			std::cout << "found video stream " << avcodec_get_name(stream->codec->codec_id) << std::endl;
-			videoStream = stream;
-		} else if(stream->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
-			std::cout << "found audio stream " << avcodec_get_name(stream->codec->codec_id) << std::endl;
-			audioStream = stream;
-		}
+	ff::Stream vStream;
+	if(input.hasVideo()) {
+		vStream = input.videoStream();
 	}
 
-	AVCodecContext* codecCtx = videoStream->codec;
-	AVCodec* codec = avcodec_find_decoder(codecCtx->codec_id);
-	if(!codec) std::cout << "cannot find decoder" << std::endl;
-
-	res = avcodec_open2(codecCtx, codec, nullptr);
-	checkResult(res, "cannot open codec for decoding");
-
-	// coder
-	AVCodec* dstVCodec = avcodec_find_encoder(AV_CODEC_ID_H264);
-	if(!dstVCodec) std::cout << "cannot find encoder" << std::endl;
-
-	AVStream* outVideoStream = avformat_new_stream(outFmtCtx, dstVCodec);
-	if(!outVideoStream) std::cout << "cannot create output video stream" << std::endl;
-
-	if (!(outFmtCtx->oformat->flags & AVFMT_NOFILE)) {
-		res = avio_open(&outFmtCtx->pb, argv[2], AVIO_FLAG_WRITE);
-		checkResult(res, "cannot open output file");
-	}
-
-	av_dump_format(outFmtCtx, 0, argv[2], 1);
-
-	AVCodecContext* dstVCodecCtx = outVideoStream->codec;
-	dstVCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
-	dstVCodecCtx->width = codecCtx->width;
-	dstVCodecCtx->height = codecCtx->height;
-	//dstVCodecCtx->time_base = codecCtx->time_base;
-	outVideoStream->time_base = codecCtx->time_base;
-	outFmtCtx->duration = inFmtCtx->duration;
-
-	if(outFmtCtx->oformat->flags & AVFMT_GLOBALHEADER)
-		dstVCodecCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
-
-	res = avcodec_open2(dstVCodecCtx, dstVCodec, nullptr);
-	checkResult(res, "cannot open codec for encoding");
-
-	res = avformat_write_header(outFmtCtx, nullptr);
-	checkResult(res, "error writing header to output file");
+	ff::Codec vDecoder = vStream.codec();
+	ff::Stream outVStream = output.addStream(AV_CODEC_ID_H264, vDecoder.width(), vDecoder.height(), AV_PIX_FMT_YUV420P);
+	outVStream.setTimeBase(vDecoder.timeBase());
+	ff::Codec vEncoder = outVStream.codec();
+	output.writeHeader();
 
 	AVFrame* frame = nullptr;
     int gotPicture = 0, gotPacket = 0, decodedFrames = 1;
@@ -83,15 +41,15 @@ int main(int argc, char** argv) {
 		AVPacket packet;
 		packet.data = nullptr;
 		packet.size = 0;
-		res = av_read_frame(inFmtCtx, &packet);
+		int res = av_read_frame(input, &packet);
 		if(res < 0) break;
 
 		frame = av_frame_alloc();
 		if(!frame) break;
 
-		AVMediaType packetType = inFmtCtx->streams[packet.stream_index]->codec->codec_type;
+		AVMediaType packetType = ((AVFormatContext*)input)->streams[packet.stream_index]->codec->codec_type;
 		if(packetType == AVMEDIA_TYPE_VIDEO) {
-			res = avcodec_decode_video2(codecCtx, frame, &gotPicture, &packet);
+			res = avcodec_decode_video2(vDecoder, frame, &gotPicture, &packet);
 			if(res < 0) {
 				av_frame_free(&frame);
 				break;
@@ -108,7 +66,7 @@ int main(int argc, char** argv) {
 				av_init_packet(&encPacket);
 				encPacket.stream_index = 0;
 
-				res = avcodec_encode_video2(dstVCodecCtx, &encPacket, frame, &gotPacket);
+				res = avcodec_encode_video2(vEncoder, &encPacket, frame, &gotPacket);
 				av_frame_free(&frame);
 				if(res < 0) break;
 				if(!gotPacket) continue;
@@ -127,9 +85,9 @@ int main(int argc, char** argv) {
 				oldPts = encPacket.pts;
 				oldDts = encPacket.dts;
 
-				av_packet_rescale_ts(&encPacket, videoStream->time_base, outVideoStream->time_base);
+				av_packet_rescale_ts(&encPacket, vStream.timeBase(), outVStream.timeBase());
 
-				res = av_interleaved_write_frame(outFmtCtx, &encPacket);
+				res = av_interleaved_write_frame(output, &encPacket);
 				checkResult(res, "cannot write frame to output file");
 				if(res < 0) break;
 			}
@@ -139,7 +97,7 @@ int main(int argc, char** argv) {
 	}
 
     // flush encoder
-    if(dstVCodecCtx->codec->capabilities & AV_CODEC_CAP_DELAY) {
+    if(vEncoder.capabilities() & AV_CODEC_CAP_DELAY) {
         std::cout << "flushing encoder" << std::endl;
         int gotFrame = 0;
         while (1) {
@@ -148,15 +106,15 @@ int main(int argc, char** argv) {
             encPacket.size = 0;
             av_init_packet(&encPacket);
             encPacket.stream_index = 0;
-            res = avcodec_encode_video2(dstVCodecCtx, &encPacket, nullptr, &gotFrame);
+            int res = avcodec_encode_video2(vEncoder, &encPacket, nullptr, &gotFrame);
             if (res < 0) {
 	            std::cout << "avcodec_encode_video2 failed" << std::endl;
 	            break;
             }
             if (gotFrame) {
                 //std::cout << "extra frame" << std::endl;
-	            av_packet_rescale_ts(&encPacket, videoStream->time_base, outVideoStream->time_base);
-                res = av_interleaved_write_frame(outFmtCtx, &encPacket);
+	            av_packet_rescale_ts(&encPacket, vStream.timeBase(), outVStream.timeBase());
+                res = av_interleaved_write_frame(output, &encPacket);
 	            checkResult(res, "[flush encoder] cannot write frame to output file");
             } else {
 	            break;
@@ -164,19 +122,7 @@ int main(int argc, char** argv) {
         }
     }
 
-    res = av_write_trailer(outFmtCtx);
-    checkResult(res, "error writing trailer to output file");
-
-	if(codecCtx)
-		avcodec_close(codecCtx);
-
-	if(dstVCodecCtx)
-		avcodec_close(dstVCodecCtx);
-
-	if(inFmtCtx)
-		avformat_close_input(&inFmtCtx);
-
-	avformat_free_context(outFmtCtx);
+	output.writeTrailer();
 
 	return 0;
 }