Refactor FFmpegReader GetAVFrame (for AV1 & async decoding)

doc/INSTALL-WINDOWS.md

@@ -193,6 +193,7 @@ pacman -Syu
 ```
 pacman -S --needed base-devel mingw-w64-x86_64-toolchain
 pacman -S mingw64/mingw-w64-x86_64-ffmpeg
+pacman -S mingw64/mingw-w64-x86_64-qt5
 pacman -S mingw64/mingw-w64-x86_64-python3-pyqt5
 pacman -S mingw64/mingw-w64-x86_64-swig
 pacman -S mingw64/mingw-w64-x86_64-cmake
@@ -202,6 +203,11 @@ pacman -S mingw32/mingw-w64-i686-zeromq
 pacman -S mingw64/mingw-w64-x86_64-python3-pyzmq
 pacman -S mingw64/mingw-w64-x86_64-python3-cx_Freeze
 pacman -S mingw64/mingw-w64-x86_64-ninja
+pacman -S mingw64/mingw-w64-x86_64-catch
+pacman -S mingw-w64-x86_64-python3-pyopengl
+pacman -S mingw-w64-clang-x86_64-python-pyopengl-accelerate
+pacman -S mingw-w64-x86_64-python-pyopengl-accelerate
+pacman -S mingw-w64-x86_64-python-pywin32
 pacman -S git
 
 # Install ImageMagick if needed (OPTIONAL and NOT NEEDED)
@@ -213,6 +219,7 @@ pacman -S mingw64/mingw-w64-x86_64-imagemagick
 ```
 pacman -S --needed base-devel mingw32/mingw-w64-i686-toolchain
 pacman -S mingw32/mingw-w64-i686-ffmpeg
+pacman -S mingw32/mingw-w64-i686-qt5
 pacman -S mingw32/mingw-w64-i686-python3-pyqt5
 pacman -S mingw32/mingw-w64-i686-swig
 pacman -S mingw32/mingw-w64-i686-cmake
@@ -222,6 +229,10 @@ pacman -S mingw32/mingw-w64-i686-zeromq
 pacman -S mingw32/mingw-w64-i686-python3-pyzmq
 pacman -S mingw32/mingw-w64-i686-python3-cx_Freeze
 pacman -S mingw32/mingw-w64-i686-ninja
+pacman -S mingw32/mingw-w64-i686-catch
+pacman -S mingw-w64-i686-python-pyopengl
+pacman -S mingw-w64-i686-python-pyopengl-accelerate
+pacman -S mingw-w64-i686-python-pywin32
 pacman -S git
 
 # Install ImageMagick if needed (OPTIONAL and NOT NEEDED)
@@ -237,6 +248,8 @@ pip3 install tinys3
 pip3 install github3.py
 pip3 install requests
 pip3 install meson
+pip3 install PyOpenGL
+pip3 install PyOpenGL-accelerate
 ```  
 
 7) Download Unittest++ (https://github.com/unittest-cpp/unittest-cpp) into /MSYS2/[USER]/unittest-cpp-master/
@@ -251,12 +264,50 @@ mingw32-make install
 ``` 
 git clone https://gitlab.gnome.org/GNOME/babl.git
 cd babl
-meson build --prefix=C:/msys64/mingw32
+meson build --prefix=C:/msys64/mingw64    (or `--prefix=C:/msys64/mingw32` for a 32 bit build)
 cd build
 meson install
 ```
 
-9) ZMQ++ Header (This might not be needed anymore)
+9) Install opencv (used for AI and computer vision effects)
+
+Note: Had to edit 1 header file and add a missing typedef: `typedef unsigned int uint;`
+
+``` 
+git clone https://github.com/opencv/opencv
+cd opencv/
+git checkout '4.3.0'
+cd ..
+git clone https://github.com/opencv/opencv_contrib
+cd opencv_contrib/
+git checkout '4.3.0'
+cd ..
+cd opencv
+mkdir build
+cd build
+cmake -D CMAKE_BUILD_TYPE=RELEASE -D WITH_TBB=OFF -D WITH_QT=ON -D WITH_OPENGL=ON -D OPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules -D OPENCV_GENERATE_PKGCONFIG=ON -D BUILD_opencv_python2=OFF -D BUILD_opencv_python3=ON -G "MSYS Makefiles" .. 
+make -j4 -i    (-i ignores errors on MSYS2 which happens for some reason)
+make install -i
+```
+
+10) Install ReSVG (SVG rasterizing)
+
+``` 
+git clone https://github.com/RazrFalcon/resvg
+cd resvg/c-api
+QT_DIR="C:\\msys64\\mingw64\\" cargo build --verbose --release
+  **OR**
+QT_DIR="C:\\msys64\\mingw32\\" cargo build --verbose --release
+
+cd ../
+
+# copy all required files into the system directories
+cp target/release/resvg.dll /usr/lib/
+mkdir -p /usr/include/resvg/
+cp c-api/*.h /usr/include/resvg/
+```
+
+11) ZMQ++ Header (This might not be needed anymore)
   NOTE: Download and copy zmq.hpp into the /c/msys64/mingw64/include/ folder
 
 ## Manual Dependencies

src/FFmpegReader.cpp

@@ -74,7 +74,8 @@ FFmpegReader::FFmpegReader(const std::string &path, bool inspect_reader)
 		  seek_audio_frame_found(0), seek_video_frame_found(0),is_duration_known(false), largest_frame_processed(0),
 		  current_video_frame(0), packet(NULL), max_concurrent_frames(OPEN_MP_NUM_PROCESSORS), audio_pts(0),
 		  video_pts(0), pFormatCtx(NULL), videoStream(-1), audioStream(-1), pCodecCtx(NULL), aCodecCtx(NULL),
-		  pStream(NULL), aStream(NULL), pFrame(NULL), previous_packet_location{-1,0} {
+		  pStream(NULL), aStream(NULL), pFrame(NULL), previous_packet_location{-1,0},
+		  resend_packet(false) {
 
 	// Initialize FFMpeg, and register all formats and codecs
 	AV_REGISTER_ALL
@@ -213,6 +214,7 @@ void FFmpegReader::Open() {
 		pFormatCtx = NULL;
 		{
 			hw_de_on = (openshot::Settings::Instance()->HARDWARE_DECODER == 0 ? 0 : 1);
+			ZmqLogger::Instance()->AppendDebugMethod("Decode hardware acceleration settings", "hw_de_on", hw_de_on, "HARDWARE_DECODER", openshot::Settings::Instance()->HARDWARE_DECODER);
 		}
 
 		// Open video file
@@ -646,6 +648,7 @@ void FFmpegReader::Close() {
 
 		// Reset some variables
 		last_frame = 0;
+		resend_packet = false;
 		largest_frame_processed = 0;
 		seek_audio_frame_found = 0;
 		seek_video_frame_found = 0;
@@ -952,11 +955,13 @@ std::shared_ptr<Frame> FFmpegReader::ReadStream(int64_t requested_frame) {
 			break;
 		}
 
-		// Get the next packet
-		packet_error = GetNextPacket();
-		if (packet_error < 0 && !packet) {
-			// No more packets to be found
-			packet_status.packets_eof = true;
+		if (!resend_packet || !packet) {
+			// Get the next packet
+			packet_error = GetNextPacket();
+			if (packet_error < 0 && !packet) {
+				// No more packets to be found
+				packet_status.packets_eof = true;
+			}
 		}
 
 		// Debug output
@@ -977,7 +982,7 @@ std::shared_ptr<Frame> FFmpegReader::ReadStream(int64_t requested_frame) {
 
 		// Video packet
 		if ((info.has_video && packet && packet->stream_index == videoStream) ||
-			(info.has_video && !packet && packet_status.video_decoded < packet_status.video_read) ||
+			(info.has_video && packet_status.video_decoded < packet_status.video_read) ||
 			(info.has_video && !packet && !packet_status.video_eof)) {
 			// Process Video Packet
 			ProcessVideoPacket(requested_frame);
@@ -1104,96 +1109,137 @@ bool FFmpegReader::GetAVFrame() {
 	AVFrame *next_frame = AV_ALLOCATE_FRAME();
 
 #if IS_FFMPEG_3_2
-	int send_packet_err = avcodec_send_packet(pCodecCtx, packet);
+	int send_packet_err = 0;
+	int64_t send_packet_pts = 0;
+	if ((packet && packet->stream_index == videoStream && !resend_packet) || !packet) {
+		send_packet_err = avcodec_send_packet(pCodecCtx, packet);
+
+		if (packet && send_packet_err >= 0) {
+			send_packet_pts = GetPacketPTS();
+			resend_packet = false;
+			ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (send packet succeeded)",
+													 "send_packet_err", send_packet_err, "send_packet_pts",
+													 send_packet_pts);
+		}
+	}
 
 	#if USE_HW_ACCEL
 		// Get the format from the variables set in get_hw_dec_format
 		hw_de_av_pix_fmt = hw_de_av_pix_fmt_global;
 		hw_de_av_device_type = hw_de_av_device_type_global;
 	#endif // USE_HW_ACCEL
 		if (send_packet_err < 0 && send_packet_err != AVERROR_EOF) {
-			ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (Packet not sent)",
-											"send_packet_err", send_packet_err);
-		}
-		else {
-			int receive_frame_err = 0;
-			AVFrame *next_frame2;
-	#if USE_HW_ACCEL
-			if (hw_de_on && hw_de_supported) {
-				next_frame2 = AV_ALLOCATE_FRAME();
+			ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (send packet: Not sent [" + av_err2string(send_packet_err) + "])", "send_packet_err", send_packet_err, "send_packet_pts", send_packet_pts);
+			if (send_packet_err == AVERROR(EAGAIN)) {
+				resend_packet = true;
+				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (send packet: AVERROR(EAGAIN): user must read output with avcodec_receive_frame()", "send_packet_pts", send_packet_pts);
 			}
-			else
-	#endif // USE_HW_ACCEL
-			{
-				next_frame2 = next_frame;
+			if (send_packet_err == AVERROR(EINVAL)) {
+				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (send packet: AVERROR(EINVAL): codec not opened, it is an encoder, or requires flush", "send_packet_pts", send_packet_pts);
+			}
+			if (send_packet_err == AVERROR(ENOMEM)) {
+				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (send packet: AVERROR(ENOMEM): failed to add packet to internal queue, or legitimate decoding errors", "send_packet_pts", send_packet_pts);
 			}
-			pFrame = AV_ALLOCATE_FRAME();
-			while (receive_frame_err >= 0) {
-				receive_frame_err = avcodec_receive_frame(pCodecCtx, next_frame2);
+		}
+
+		// Always try and receive a packet, if not EOF.
+		// Even if the above avcodec_send_packet failed to send,
+		// we might still need to receive a packet.
+		int receive_frame_err = 0;
+		AVFrame *next_frame2;
+#if USE_HW_ACCEL
+		if (hw_de_on && hw_de_supported) {
+			next_frame2 = AV_ALLOCATE_FRAME();
+		}
+		else
+#endif // USE_HW_ACCEL
+		{
+			next_frame2 = next_frame;
+		}
+		pFrame = AV_ALLOCATE_FRAME();
+		while (receive_frame_err >= 0) {
+			receive_frame_err = avcodec_receive_frame(pCodecCtx, next_frame2);
+
+			if (receive_frame_err != 0) {
+				ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (receive frame: frame not ready yet from decoder [\" + av_err2string(receive_frame_err) + \"])", "receive_frame_err", receive_frame_err, "send_packet_pts", send_packet_pts);
 
 				if (receive_frame_err == AVERROR_EOF) {
-					ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (EOF detected from decoder)");
+					ZmqLogger::Instance()->AppendDebugMethod(
+							"FFmpegReader::GetAVFrame (receive frame: AVERROR_EOF: EOF detected from decoder, flushing buffers)", "send_packet_pts", send_packet_pts);
+					avcodec_flush_buffers(pCodecCtx);
 					packet_status.video_eof = true;
 				}
-				if (receive_frame_err == AVERROR(EINVAL) || receive_frame_err == AVERROR_EOF) {
-					ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (invalid frame received or EOF from decoder)");
+				if (receive_frame_err == AVERROR(EINVAL)) {
+					ZmqLogger::Instance()->AppendDebugMethod(
+							"FFmpegReader::GetAVFrame (receive frame: AVERROR(EINVAL): invalid frame received, flushing buffers)", "send_packet_pts", send_packet_pts);
 					avcodec_flush_buffers(pCodecCtx);
 				}
-				if (receive_frame_err != 0) {
-					ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (frame not ready yet from decoder)");
-					break;
+				if (receive_frame_err == AVERROR(EAGAIN)) {
+					ZmqLogger::Instance()->AppendDebugMethod(
+							"FFmpegReader::GetAVFrame (receive frame: AVERROR(EAGAIN): output is not available in this state - user must try to send new input)", "send_packet_pts", send_packet_pts);
 				}
-
-	#if USE_HW_ACCEL
-				if (hw_de_on && hw_de_supported) {
-					int err;
-					if (next_frame2->format == hw_de_av_pix_fmt) {
-						next_frame->format = AV_PIX_FMT_YUV420P;
-						if ((err = av_hwframe_transfer_data(next_frame,next_frame2,0)) < 0) {
-							ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (Failed to transfer data to output frame)");
-						}
-						if ((err = av_frame_copy_props(next_frame,next_frame2)) < 0) {
-							ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (Failed to copy props to output frame)");
-						}
-					}
-				}
-				else
-	#endif // USE_HW_ACCEL
-				{	// No hardware acceleration used -> no copy from GPU memory needed
-					next_frame = next_frame2;
-				}
-
-				// TODO also handle possible further frames
-				// Use only the first frame like avcodec_decode_video2
-				frameFinished = 1;
-				packet_status.video_decoded++;
-
-				av_image_alloc(pFrame->data, pFrame->linesize, info.width, info.height, (AVPixelFormat)(pStream->codecpar->format), 1);
-				av_image_copy(pFrame->data, pFrame->linesize, (const uint8_t**)next_frame->data, next_frame->linesize,
-											(AVPixelFormat)(pStream->codecpar->format), info.width, info.height);
-
-				// Get display PTS from video frame, often different than packet->pts.
-				// Sending packets to the decoder (i.e. packet->pts) is async,
-				// and retrieving packets from the decoder (frame->pts) is async. In most decoders
-				// sending and retrieving are separated by multiple calls to this method.
-				if (next_frame->pts != AV_NOPTS_VALUE) {
-					// This is the current decoded frame (and should be the pts used) for
-					// processing this data
-					video_pts = next_frame->pts;
-				} else if (next_frame->pkt_dts != AV_NOPTS_VALUE) {
-					// Some videos only set this timestamp (fallback)
-					video_pts = next_frame->pkt_dts;
+				if (receive_frame_err == AVERROR_INPUT_CHANGED) {
+					ZmqLogger::Instance()->AppendDebugMethod(
+							"FFmpegReader::GetAVFrame (receive frame: AVERROR_INPUT_CHANGED: current decoded frame has changed parameters with respect to first decoded frame)", "send_packet_pts", send_packet_pts);
 				}
 
-				// break out of loop after each successful image returned
+				// Break out of decoding loop
+				// Nothing ready for decoding yet
 				break;
 			}
-	#if USE_HW_ACCEL
+
+#if USE_HW_ACCEL
 			if (hw_de_on && hw_de_supported) {
-				AV_FREE_FRAME(&next_frame2);
+				int err;
+				if (next_frame2->format == hw_de_av_pix_fmt) {
+					next_frame->format = AV_PIX_FMT_YUV420P;
+					if ((err = av_hwframe_transfer_data(next_frame,next_frame2,0)) < 0) {
+						ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (Failed to transfer data to output frame)", "hw_de_on", hw_de_on);
+					}
+					if ((err = av_frame_copy_props(next_frame,next_frame2)) < 0) {
+						ZmqLogger::Instance()->AppendDebugMethod("FFmpegReader::GetAVFrame (Failed to copy props to output frame)", "hw_de_on", hw_de_on);
+					}
+				}
 			}
-	#endif // USE_HW_ACCEL
+			else
+#endif // USE_HW_ACCEL
+			{	// No hardware acceleration used -> no copy from GPU memory needed
+				next_frame = next_frame2;
+			}
+
+			// TODO also handle possible further frames
+			// Use only the first frame like avcodec_decode_video2
+			frameFinished = 1;
+			packet_status.video_decoded++;
+
+			av_image_alloc(pFrame->data, pFrame->linesize, info.width, info.height, (AVPixelFormat)(pStream->codecpar->format), 1);
+			av_image_copy(pFrame->data, pFrame->linesize, (const uint8_t**)next_frame->data, next_frame->linesize,
+										(AVPixelFormat)(pStream->codecpar->format), info.width, info.height);
+
+			// Get display PTS from video frame, often different than packet->pts.
+			// Sending packets to the decoder (i.e. packet->pts) is async,
+			// and retrieving packets from the decoder (frame->pts) is async. In most decoders
+			// sending and retrieving are separated by multiple calls to this method.
+			if (next_frame->pts != AV_NOPTS_VALUE) {
+				// This is the current decoded frame (and should be the pts used) for
+				// processing this data
+				video_pts = next_frame->pts;
+			} else if (next_frame->pkt_dts != AV_NOPTS_VALUE) {
+				// Some videos only set this timestamp (fallback)
+				video_pts = next_frame->pkt_dts;
+			}
+
+			ZmqLogger::Instance()->AppendDebugMethod(
+					"FFmpegReader::GetAVFrame (Successful frame received)", "video_pts", video_pts, "send_packet_pts", send_packet_pts);
+
+			// break out of loop after each successful image returned
+			break;
 		}
+#if USE_HW_ACCEL
+		if (hw_de_on && hw_de_supported) {
+			AV_FREE_FRAME(&next_frame2);
+		}
+	#endif // USE_HW_ACCEL
 #else
 		avcodec_decode_video2(pCodecCtx, next_frame, &frameFinished, packet);
 
@@ -1744,6 +1790,7 @@ void FFmpegReader::Seek(int64_t requested_frame) {
 	video_pts_seconds = NO_PTS_OFFSET;
 	audio_pts = 0.0;
 	audio_pts_seconds = NO_PTS_OFFSET;
+	resend_packet = false;
 	last_frame = 0;
 	current_video_frame = 0;
 	largest_frame_processed = 0;

src/FFmpegReader.h

@@ -153,6 +153,7 @@ namespace openshot {
 
 		int64_t audio_pts;
 		int64_t video_pts;
+		bool resend_packet;
 		double pts_offset_seconds;
 		double audio_pts_seconds;
 		double video_pts_seconds;