Newest 'libx264' Questions - Stack Overflow

http://stackoverflow.com/questions/tagged/libx264

Les articles publiés sur le site

  • OpenCV VideoWriter using ffmpeg with "Could not open codec 'libx264'" Error

    17 avril, par user2262504

    I 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:

    1. anyone knows where and how OpenCV invoke ffmpeg API?
    2. how to change ffmpeg default settings using code, hopefull, can be easily embeded into OpenCV?
    3. 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/build
    

    FFMPEG

    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

    6 avril, par userDtrm

    I'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://192.168.1.8:5001
    

    The ffplay command used to display the video feed is,

    ffplay -analyzeduration 1 -fflags -nobuffer -i udp://192.168.1.8:5001
    

    However, 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?
  • How to set correct parameters for x264 lib

    1er avril, par galuk

    I depacketize the H264 video fragments from an IP.RTP stream and save them to video.ivf file. After depacketizing i have only [SPS] ,[PPS] and [non-IDR slice]. I try to create IDR slice by using x264 lib. x264 lib creates IDR frame which consists of 0x000001[SPS nal type 7] 0x000001[PPS nal type 8] 0x0001[SE slice nal type 6] and 0x0001[I slice nal type 5]. How to set correct parameters for x264 lib if i have real SPS and PPS frames to get the same SPS and PPS frames

    i parse SPS and PPS but i don't know which parameters of x264_param_t param i should set. can someone give me some examples.

  • How to transcode short video using FFmpeg, libx264 codec, Swift, iOS app

    21 mars, par Dmitriy iOS

    The goal is to transcode a short video into .mov format using FFmpeg and libx264 codec. So far I have not been able to do this using third-party libraries. Using the command line, the video is perfectly transcoded, but I need it inside the application.

    If anyone has a solution I would be very grateful.

    The resulting video needs to have the following parameters, something like this:

    Picture 1 Picture 2 Picture 3

    For example:

    let command = ["ffmpeg", "-i", videoOutputURL.path, "-c:v", "libx264", "-c:a", "copy", convertedVideoUrl.path]
    let ffmpegCommand = ffmpeg(command)
    
  • ffmpeg Connection to tcp ://127.0.0.1:1935 refused on Windows 10

    6 mars, par Wissam Elias

    I am trying to re-stream an RTSP connection on the local network using this command:

    ffmpeg -loglevel debug -rtsp_transport tcp -i rtsp://192.168.1.13:1935 -codec copy -f rtsp rtsp://172.0.0.1:1935/live/stream
    

    but i am getting an error message:

    [tcp @ 0000020c99c4c1c0] Connection to tcp://127.0.0.1:1935 failed: Connection refused
    rtsp://127.0.0.1:1935/live/stream: Connection refused
    

    while the port is not used and I've tried to use 8554 also with the same result, and the firewall on my device is turned off.