asqz's profile - activity

Hi,

I know that opencv use ffmpeg to encode/decode vidoe, and I am interested in studying it for personal reuse. The problem is that I read the sources in the directory /opencv/opencv/modules/highgui/src (all the file with ffmpeg in the name) but haven't been able to locate the function which encode decode data. Can you help me finding it ?

Any help would be appreciate. Thanks.

Hi,

I have a pointer to encoded image or video data. I want to know if there is a way (a function ?) which took a data pointer, a codec type that decode it so that I can display it.

Any help would be appreciate. Thanks.

I found the solution and described it here.

Thanks for all your answers, but I am not using CMake. Here is the makefile I created :

########LIBRAIRIES

LIBS_ffmpeg = -lm -lz -lpthread -lavformat -lavcodec -lavutil

LIBS_opencv = -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_video -lopencv_objdetect

LIBS_autres = -lpthread -ldl -lm

LIBS = $(LIBS_autres) $(LIBS_ffmpeg) $(LIBS_opencv)

########CONSTANTES

CXXFLAGS = -O2 -g -Wall -fmessage-length=0 -D__STDC_CONSTANT_MACROS OBJS = test.o FluxVideo.o TARGET = test

########REGLES

$(TARGET): $(OBJS) $(CXX) -o $(TARGET) $(OBJS) $(LIBS)

%.o: %.cpp $(CXX) -o $@ -c $< $(CXXFLAGS) $(LIBS)

all: $(TARGET)

clean: rm -f $(OBJS) $(TARGET)

The problem is that the makefile I am using is incorrect. You can find a correct makefile at this address : http://answers.opencv.org/question/14611/example-of-makefile/

Hi,

I want to create a program which display a RTSP stream. For some reason I don't want to use the cvCaptureFromFile function. I have a AVFormatContext structure (which is a FFMpeg structure containing video and audio stream) and I want to use it in a new OpenCV function I want to use the ffmpeg programming library, not the ffmpeg commands.

Thanks

PS : thanks StevenPuttemans for your answer but no this topics are not relevant because they are about OpenCV's functions which use ffmpeg, not using ffmpeg and OpenCV in the Same program. I can't answer you with a new post because my answers are blocked.

Hi, I want to display a rtsp stream and display it in a window. But this lines :

avformat_network_init();

CvCapture *camera = cvCaptureFromFile("rtsp://192.168.253.14/video/input3/encoder1/transmitter3");

trigger the following error message :

[mpeg4 @ 0x2102ea0] hmm, seems the headers are not complete, trying to guess time_increment_bits [mpeg4 @ 0x2102ea0] my guess is 5 bits ;) [mpeg4 @ 0x2102ea0] hmm, seems the headers are not complete, trying to guess time_increment_bits [mpeg4 @ 0x2102ea0] my guess is 5 bits ;) [mpeg4 @ 0x2102ea0] looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag [mpeg4 @ 0x2102ea0] [IMGUTILS @ 0x7fff64efb200] Picture size 0x0 is invalid [mpeg4 @ 0x2102ea0] get_buffer() failed (-1 0 (nil)) [mpeg4 @ 0x2102ea0] [IMGUTILS @ 0x7fff64efb200] Picture size 0x0 is invalid [the same repeted many time...]

[mpeg4 @ 0x2102ea0] get_buffer() failed (-1 0 (nil)) [rtsp @ 0x20fefa0] Estimating duration from bitrate, this may be inaccurate

This are only warning because the the stream display the right images, but i want my code to be clean. Moroever the window doesn't notice my key press. Can you help me fix this problem please.

Hi,

I am trying to create a makefile for a program which use openCV, but I can't create one. One thing that could help me is an example of a makefile you are using which you know work, so that I could take as a reference for writing my own makefile. Could you publish one please ? I am using ubuntu 12.04

Hi, I am trying to compile my program, using this makefile :

CXXFLAGS += pkg-config opencv --cflags

LDFLAGS += pkg-config opencv --libs

TARGET = test

$(TARGET): $(OBJS) $(CXX) -o $(TARGET) $(LDFLAGS) $(OBJS)

%.o: %.cpp $(CXX) -o $@ -c $< $(CXXFLAGS) $(LIBS)

all: $(TARGET)

The source code is test.cpp :

#include <cv.h> #include <highgui.h>

int main(void) { cv::Mat image; }

It trigger the following error message :

g++ -o test.o -c test.cpp -O2 -g -Wall -fmessage-length=0 pkg-config opencv --cflags g++ -o test pkg-config opencv --libs test.o test.o: In function cv::Mat::release()': /usr/include/opencv2/core/mat.hpp:382: undefined reference tocv::Mat::deallocate()' test.o: In function ~Mat': /usr/include/opencv2/core/mat.hpp:297: undefined reference tocv::fastFree(void)' collect2: ld returned 1 exit status make: ** [test] Error 1

Can you help me solve this problem please ?