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OpenCV VideoWriter using ffmpeg with "Could not open codec 'libx264'" Error
19 avril, par user2262504I am new to OpenCV, and I want write Mat images into video using VideoWriter on Ubuntu 12.04. But when constructing VideoWriter, errors came out.
It seems that OpenCV invoke ffmpeg API using default parameters and ffmpeg invoke x264 using its default parameters. Then these setting is broken for libx264. Thus the "Could not open codec 'libx264'" error.
Anyone has ideas to solve this problem?
More specifically:
- anyone knows where and how OpenCV invoke ffmpeg API?
- how to change ffmpeg default settings using code, hopefull, can be easily embeded into OpenCV?
- will changes of default in ffmpeg be carried to libx264?
Errors:
1. Uising CV_FOURCC('H', '2', '6', '4') [libx264 @ 0x255de40] broken ffmpeg default settings detected [libx264 @ 0x255de40] use an encoding preset (e.g. -vpre medium) [libx264 @ 0x255de40] preset usage: -vpre-vpre [libx264 @ 0x255de40] speed presets are listed in x264 --help [libx264 @ 0x255de40] profile is optional; x264 defaults to high Could not open codec 'libx264': Unspecified error 2. Using FOURCC = -1 to invoke user customized codec OpenCV Error: Unsupported format or combination of formats (Gstreamer Opencv backend doesn't support this codec acutally.) in CvVideoWriter_GStreamer::open, file /home/XXX/Downloads/opencv-2.4.8/modules/highgui/src/cap_gstreamer.cpp, line 505 terminate called after throwing an instance of 'cv::Exception' what(): /home/XXX/Downloads/opencv-2.4.8/modules/highgui/src/cap_gstreamer.cpp: 505: error: (-210) Gstreamer Opencv backend doesn't support this codec acutally. in function CvVideoWriter_GStreamer::open Codes:
int main(int argc, char *argv[]) { VideoWriter outputVideo; bool fourcc_on = true; //switch on / off different error if (fourcc_on) outputVideo.open("outVideo.avi", CV_FOURCC('H', '2', '6', '4'), 25, Size(100, 100), true); else outputVideo.open("outVideo.avi", -1, 25, Size(100, 100), true); if (!outputVideo.isOpened()) { cout << "Could not open the output video for write" << endl; return -1; } return 0; }OpenCV Configuration:
-- Detected version of GNU GCC: 46 (406) -- Found OpenEXR: /usr/lib/libIlmImf.so -- Looking for linux/videodev.h -- Looking for linux/videodev.h - not found -- Looking for linux/videodev2.h -- Looking for linux/videodev2.h - found -- Looking for sys/videoio.h -- Looking for sys/videoio.h - not found -- Looking for libavformat/avformat.h -- Looking for libavformat/avformat.h - found -- Looking for ffmpeg/avformat.h -- Looking for ffmpeg/avformat.h - not found -- Could NOT find JNI (missing: JAVA_INCLUDE_PATH JAVA_INCLUDE_PATH2 JAVA_AWT_INCLUDE_PATH) -- -- General configuration for OpenCV 2.4.8 ===================================== -- Version control: unknown -- -- Platform: -- Host: Linux 3.8.0-38-generic x86_64 -- CMake: 2.8.7 -- CMake generator: Unix Makefiles -- CMake build tool: /usr/bin/make -- Configuration: RELEASE -- -- C/C++: -- Built as dynamic libs?: YES -- C++ Compiler: /usr/bin/c++ (ver 4.6) -- C++ flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -O3 -DNDEBUG -DNDEBUG -- C++ flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -g -O0 -DDEBUG -D_DEBUG -- C Compiler: /usr/bin/gcc -- C flags (Release): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -O3 -DNDEBUG -DNDEBUG -- C flags (Debug): -fsigned-char -W -Wall -Werror=return-type -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -msse3 -ffunction-sections -g -O0 -DDEBUG -D_DEBUG -- Linker flags (Release): -- Linker flags (Debug): -- Precompiled headers: YES -- -- OpenCV modules: -- To be built: core flann imgproc highgui features2d calib3d ml video legacy objdetect photo gpu ocl nonfree contrib python stitching superres ts videostab -- Disabled: world -- Disabled by dependency: - -- Unavailable: androidcamera dynamicuda java -- -- GUI: -- QT: NO -- GTK+ 2.x: YES (ver 2.24.10) -- GThread : YES (ver 2.32.4) -- GtkGlExt: NO -- OpenGL support: NO -- -- Media I/O: -- ZLib: /usr/lib/x86_64-linux-gnu/libz.so (ver 1.2.3.4) -- JPEG: /usr/lib/x86_64-linux-gnu/libjpeg.so (ver ) -- PNG: /usr/lib/x86_64-linux-gnu/libpng.so (ver 1.2.46) -- TIFF: /usr/lib/x86_64-linux-gnu/libtiff.so (ver 42 - 3.9.5) -- JPEG 2000: /usr/lib/x86_64-linux-gnu/libjasper.so (ver 1.900.1) -- OpenEXR: /usr/lib/libImath.so /usr/lib/libIlmImf.so /usr/lib/libIex.so /usr/lib/libHalf.so /usr/lib/libIlmThread.so (ver 1.6.1) -- -- Video I/O: -- DC1394 1.x: NO -- DC1394 2.x: YES (ver 2.2.0) -- FFMPEG: YES -- codec: YES (ver 55.58.105) -- format: YES (ver 55.37.101) -- util: YES (ver 52.78.100) -- swscale: YES (ver 2.6.100) -- gentoo-style: YES -- GStreamer: -- base: YES (ver 0.10.36) -- app: YES (ver 0.10.36) -- video: YES (ver 0.10.36) -- OpenNI: NO -- OpenNI PrimeSensor Modules: NO -- PvAPI: NO -- GigEVisionSDK: NO -- UniCap: NO -- UniCap ucil: NO -- V4L/V4L2: Using libv4l (ver 1.0.1) -- XIMEA: NO -- Xine: NO -- -- Other third-party libraries: -- Use IPP: NO -- Use Eigen: NO -- Use TBB: NO -- Use OpenMP: NO -- Use GCD NO -- Use Concurrency NO -- Use C=: NO -- Use Cuda: NO -- Use OpenCL: YES -- -- OpenCL: -- Version: dynamic -- Include path: /home/shixudongleo/Downloads/opencv-2.4.8/3rdparty/include/opencl/1.2 -- Use AMD FFT: NO -- Use AMD BLAS: NO -- -- Python: -- Interpreter: /usr/bin/python (ver 2.7.3) -- Libraries: /usr/lib/libpython2.7.so -- numpy: /usr/lib/python2.7/dist-packages/numpy/core/include (ver 1.6.1) -- packages path: lib/python2.7/dist-packages -- -- Java: -- ant: NO -- JNI: NO -- Java tests: NO -- -- Documentation: -- Build Documentation: NO -- Sphinx: NO -- PdfLaTeX compiler: /usr/bin/pdflatex -- -- Tests and samples: -- Tests: YES -- Performance tests: YES -- C/C++ Examples: NO -- -- Install path: /usr/local -- -- cvconfig.h is in: /home/shixudongleo/Downloads/opencv-2.4.8/build -- ----------------------------------------------------------------- -- -- Configuring done -- Generating done -- Build files have been written to: /home/XXX/Downloads/opencv-2.4.8/buildFFMPEG
ffmpeg is enable to support OpenCV and libx264 is enabled when compiling ffmpeg. By using ffmpeg command line, libx264 is running normally.
$ ffmpeg -i test.avi -vcodec libx264 test.mp4 ffmpeg -i test.avi -vcodec libx264 test.mp4 > ~/Downloads/ffmpeg_log.txt ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers built on Apr 24 2014 16:39:51 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-nonfree --enable-postproc --enable-version3 --enable-x11grab --enable-shared --enable-pic libavutil 52. 78.100 / 52. 78.100 libavcodec 55. 58.105 / 55. 58.105 libavformat 55. 37.101 / 55. 37.101 libavdevice 55. 13.100 / 55. 13.100 libavfilter 4. 4.100 / 4. 4.100 libswscale 2. 6.100 / 2. 6.100 libswresample 0. 18.100 / 0. 18.100 libpostproc 52. 3.100 / 52. 3.100 Input #0, avi, from 'test.avi': Duration: 00:00:03.73, start: 0.000000, bitrate: 1757 kb/s Stream #0:0: Video: msvideo1 (CRAM / 0x4D415243), rgb555le, 320x240, 1781 kb/s, 15 tbr, 15 tbn, 15 tbc Metadata: title : julius.avi Video #1 File 'test.mp4' already exists. Overwrite ? [y/N] y No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. [libx264 @ 0x25d08e0] using cpu capabilities: none! [libx264 @ 0x25d08e0] profile High 4:4:4 Predictive, level 1.2, 4:4:4 8-bit [libx264 @ 0x25d08e0] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=12 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=15 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'test.mp4': Metadata: encoder : Lavf55.37.101 Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv444p, 320x240, q=-1--1, 15360 tbn, 15 tbc Metadata: title : julius.avi Video #1 Stream mapping: Stream #0:0 -> #0:0 (msvideo1 -> libx264) Press [q] to stop, [?] for help frame= 56 fps=0.0 q=-1.0 Lsize= 321kB time=00:00:03.60 bitrate= 731.0kbits/s video:320kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.409949% [libx264 @ 0x25d08e0] frame I:3 Avg QP:15.36 size: 7975 [libx264 @ 0x25d08e0] frame P:38 Avg QP:26.05 size: 6230 [libx264 @ 0x25d08e0] frame B:15 Avg QP:28.25 size: 4418 [libx264 @ 0x25d08e0] consecutive B-frames: 46.4% 53.6% 0.0% 0.0% [libx264 @ 0x25d08e0] mb I I16..4: 1.4% 72.8% 25.8% [libx264 @ 0x25d08e0] mb P I16..4: 1.6% 5.7% 15.1% P16..4: 7.6% 6.3% 7.4% 0.0% 0.0% skip:56.3% [libx264 @ 0x25d08e0] mb B I16..4: 0.2% 1.0% 2.0% B16..8: 13.3% 7.8% 8.7% direct: 8.3% skip:58.8% L0:34.9% L1:36.6% BI:28.5% [libx264 @ 0x25d08e0] 8x8 transform intra:37.7% inter:2.3% [libx264 @ 0x25d08e0] coded y,u,v intra: 52.1% 42.1% 30.1% inter: 19.6% 9.2% 5.2% [libx264 @ 0x25d08e0] i16 v,h,dc,p: 56% 17% 24% 2% [libx264 @ 0x25d08e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 10% 16% 68% 1% 1% 1% 1% 1% 1% [libx264 @ 0x25d08e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19% 18% 28% 5% 6% 5% 7% 5% 6% [libx264 @ 0x25d08e0] Weighted P-Frames: Y:31.6% UV:21.1% [libx264 @ 0x25d08e0] ref P L0: 70.5% 9.0% 12.1% 6.5% 2.0% [libx264 @ 0x25d08e0] ref B L0: 91.3% 8.7% [libx264 @ 0x25d08e0] kb/s:700.56 -
very low latency streaminig with ffmpeg using a webcam
5 avril, par userDtrmI'm trying to configure ffmpeg to do a real-time video streaming using a webcam. The ffmpeg encoder command I use is as follows.
ffmpeg -f v4l2 -input_format yuyv422 -s 640x480 -i /dev/video0 -c:v libx264 -profile:v baseline -trellis 0 -subq 1 -level 32 -preset superfast -tune zerolatency -me_method epzs -crf 30 -threads 0 -bufsize 1 -refs 4 -coder 0 -b_strategy 0 -bf 0 -sc_threshold 0 -x264-params vbv-maxrate=2000:slice-max-size=1500:keyint=30:min-keyint=10: -pix_fmt yuv420p -an -f mpegts udp://192.168.1.8:5001The ffplay command used to display the video feed is,
ffplay -analyzeduration 1 -fflags -nobuffer -i udp://192.168.1.8:5001However, I'm experiencing a latency of 0.5 - 1.0s latency in the video stream. Is there a way to reduce this to a number less than 100ms. Also, when I replace the v4l2 camera capture with a screen capture using x11grab, the stream is almost real-time and I experience no noticeable delays. Moreover, changing the encoder from x264 to mpeg2 had no effect on the latency. In addition, the statistics from the ffmpeg shows that the encoder is performing at a 30fps rate, which I believe indicates that the encoding is real-time. This leaves me with only one reason for the experienced delay.
- Is there a significant delay in buffers when using v4l2 during video capturing in a webcam?
- I don't think the transmission delay is in effect in this case as I see no latencies when screen capture is used under the same conditions.
- Can this latency be further reduced?. Can someone think of a different encoder configuration to be used instead of the one that I've been using?
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Encoding problem with x264 and not divisible by 4 resolutions
23 février, par Valentin MaschenkoI'm encoding frames using H264 from BRGA to Yuv420p with high preset. It works fine with most resolutions, but images on 1366x768 are heavily distorted. So far, I've found that if width or height is not divisible by 4, there can be issues like this. Do you know how I can fix that?
Code:
stride = this.width * 4; encoder = new CodecContext(Codec.FindEncoderById(AVCodecID.H264)) { Width = this.width, Height = this.height, Framerate = new AVRational(1, framerate), TimeBase = new AVRational(1, framerate), PixelFormat = AVPixelFormat.Yuv420p, Profile = (int)FF_PROFILE.H264High, MaxBFrames = 0, GopSize = 10, }; encoder.Open(null, new MediaDictionary { ["crf"] = "22", ["tune"] = "zerolatency", ["preset"] = "veryfast", ["subme"] = "5" }); rgbFrame.Width = width; rgbFrame.Height = height; rgbFrame.Format = (int)AVPixelFormat.Bgra; unsafe { fixed (byte* ptr = frame) { rgbFrame.Data[0] = (nint)ptr; } } rgbFrame.Linesize[0] = stride; rgbFrame.Pts = pts++; yuvFrame.Width = width; yuvFrame.Height = height; yuvFrame.Format = (int)AVPixelFormat.Yuv420p; yuvFrame.EnsureBuffer(); yuvFrame.MakeWritable(); videoFrameConverter.ConvertFrame(rgbFrame, yuvFrame); yuvFrame.Pts = pts; var encodedFrames = encoder.EncodeFrame(yuvFrame, packetRef); var packet = encodedFrames.FirstOrDefault(); var data = packet?.Data.ToArray() ?? []; -
Per macroblock encoding in libx264
12 janvier, par Wei.MI know that in x264 encoding, the process is going on with the unit of macroblock. However, is that possible to set the parameters for each macroblocks? For example, if I want to let the QP of some specific area to be smaller than others. Is that possible? If I need to modify the functions and Apis in libx264, where should I begin?
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libx264 : which parameters can be changed on fly ?
12 janvier, par Dan TumaykinI know that it is possible to change some encoder parameters on fly, using x264_encoder_reconfig(). From this commit I can deduce that we can change ratecontrol parameters - but I was unable to find a clear list of parameters that may be changed.
Question: which parameters of x264 encoder can be changed on fly?
