我是OpenCV的新手，我想在Ubuntu 12.04上使用VideoWriter将Mat图像写入视频。但在构建VideoWriter时，出现了错误。
似乎OpenCV使用默认参数调用ffmpeg API，而ffmpeg使用其默认参数调用x264。然后，libx264的这些设置被破坏。因此出现"无法打开编解码器'libx264'"错误。
有人有办法解决这个问题吗？
更具体地说：
- 有人知道OpenCV在哪里以及如何调用ffmpeg API吗
- 如何使用代码更改ffmpeg的默认设置，hopefull，可以很容易地嵌入到OpenCV中
- ffmpeg中默认值的更改会被传递到libx264吗
错误：
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 <speed> -vpre <profile>
[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
代码：
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配置：
-- 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支持OpenCV，编译ffmpeg时启用libx264。通过使用ffmpeg命令行，libx264可以正常运行。
$ 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
您尝试过更改fourcc参数吗？
VideoWriter outp;
outp.open("aboutput.wmv",CV_FOURCC('M','P','4','2'),10,Size(160,160),false);
这适用于我的Ubuntu 14.04