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  • Contribute to documentation

    13 avril 2011

    Documentation is vital to the development of improved technical capabilities.
    MediaSPIP welcomes documentation by users as well as developers - including : critique of existing features and functions articles contributed by developers, administrators, content producers and editors screenshots to illustrate the above translations of existing documentation into other languages
    To contribute, register to the project users’ mailing (...)

  • Contribute to a better visual interface

    13 avril 2011

    MediaSPIP is based on a system of themes and templates. Templates define the placement of information on the page, and can be adapted to a wide range of uses. Themes define the overall graphic appearance of the site.
    Anyone can submit a new graphic theme or template and make it available to the MediaSPIP community.

  • Contribute to translation

    13 avril 2011

    You can help us to improve the language used in the software interface to make MediaSPIP more accessible and user-friendly. You can also translate the interface into any language that allows it to spread to new linguistic communities.
    To do this, we use the translation interface of SPIP where the all the language modules of MediaSPIP are available. Just subscribe to the mailing list and request further informantion on translation.
    MediaSPIP is currently available in French and English (...)

Sur d’autres sites (4547)

  • a lot of GREEN Color at YUV420p —> RGB in OpenGL 2.0 Shader on iOS

    25 octobre 2012, par 이형근

    I want to make a movie player for iOS using ffmpeg and OpenGL ES 2.0
    but I have some problem. Output RGB image has a lot of GREEN color.
    This is code and images

    • 480x320 width & height :
    • 512x512 Texture width & height

    I got a YUV420p row data from ffmpeg AVFrame.

        for (int i = 0, nDataLen = 0; i < 3; i++) {
    
        int nShift = (i == 0) ? 0 : 1;
    
        uint8_t *pYUVData = (uint8_t *)_frame->data[i];
    
        for (int j = 0; j < (mHeight >> nShift); j++) {
    
            memcpy(&pData->pOutBuffer[nDataLen], pYUVData, (mWidth >> nShift));
    
            pYUVData += _frame->linesize[i];
    
            nDataLen += (mWidth >> nShift);
    
        }
    
    }

    and prepare texture for Y, U & V channel.

    //: U Texture
    
    if (sampler1Texture) glDeleteTextures(1, &sampler1Texture);
    

    
    glActiveTexture(GL_TEXTURE1);
    
    glGenTextures(1, &sampler1Texture);
    
    glBindTexture(GL_TEXTURE_2D, sampler1Texture);
    

    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
    // This is necessary for non-power-of-two textures
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
    glEnable(GL_TEXTURE_2D);
    

    
    glTexImage2D(GL_TEXTURE_2D, 
    
                 0, 
    
                 GL_LUMINANCE, 
    
                 texW / 2, 
    
                 texH / 2, 
    
                 0, 
    
                 GL_LUMINANCE, 
    
                 GL_UNSIGNED_BYTE,
    
                 NULL);
    

    
    //: V Texture
    
    if (sampler2Texture) glDeleteTextures(1, &sampler2Texture);
    

    
    glActiveTexture(GL_TEXTURE2);
    
    glGenTextures(1, &sampler2Texture);
    
    glBindTexture(GL_TEXTURE_2D, sampler2Texture);
    

    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
    // This is necessary for non-power-of-two textures
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
    glEnable(GL_TEXTURE_2D);
    

    
    glTexImage2D(GL_TEXTURE_2D, 
    
                 0, 
    
                 GL_LUMINANCE, 
    
                 texW / 2, 
    
                 texH / 2, 
    
                 0, 
    
                 GL_LUMINANCE,
    
                 GL_UNSIGNED_BYTE,
    
                 NULL);
    

    
    //: Y Texture
    
    if (sampler0Texture) glDeleteTextures(1, &sampler0Texture);
    

    
    glActiveTexture(GL_TEXTURE0);
    
    glGenTextures(1, &sampler0Texture);
    
    glBindTexture(GL_TEXTURE_2D, sampler0Texture);
    

    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
    // This is necessary for non-power-of-two textures
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
    glEnable(GL_TEXTURE_2D);
    

    
    glTexImage2D(GL_TEXTURE_2D, 
    
                 0, 
    
                 GL_LUMINANCE, 
    
                 texW, 
    
                 texH, 
    
                 0, 
    
                 GL_LUMINANCE,
    
                 GL_UNSIGNED_BYTE, 
    
                 NULL);

    Rendering part is below.

    int _idxU = mFrameW * mFrameH;
    
int _idxV = _idxU + (_idxU / 4);
    

    
// U data
    
glActiveTexture(GL_TEXTURE1);
    
glBindTexture(GL_TEXTURE_2D, sampler1Texture);
    
glUniform1i(sampler1Uniform, 1);
    

    
glTexSubImage2D(
    
                GL_TEXTURE_2D, 
    
                0, 
    
                0, 
    
                0, 
    
                mFrameW / 2,            // source width
    
                mFrameH / 2,            // source height
    
                GL_LUMINANCE,
    
                GL_UNSIGNED_BYTE, 
    
                &_frameData[_idxU]);
    

    
// V data
    
glActiveTexture(GL_TEXTURE2);
    
glBindTexture(GL_TEXTURE_2D, sampler2Texture);
    
glUniform1i(sampler2Texture, 2);
    

    
glTexSubImage2D(
    
                GL_TEXTURE_2D, 
    
                0, 
    
                0, 
    
                0, 
    
                mFrameW / 2,            // source width
    
                mFrameH / 2,            // source height
    
                GL_LUMINANCE,
    
                GL_UNSIGNED_BYTE,
    
                &_frameData[_idxV]);
    

    
// Y data
    
glActiveTexture(GL_TEXTURE0);
    
glBindTexture(GL_TEXTURE_2D, sampler0Texture);
    
glUniform1i(sampler0Uniform, 0);
    

    
glTexSubImage2D(
    
                GL_TEXTURE_2D, 
    
                0, 
    
                0, 
    
                0, 
    
                mFrameW,            // source width
    
                mFrameH,            // source height
    
                GL_LUMINANCE,
    
                GL_UNSIGNED_BYTE,
    
                _frameData);

    Vertex Shader & Fragment Shader is below.

    attribute vec4 Position;
    
attribute vec2 TexCoordIn;
    

    
varying vec2 TexCoordOut;
    
varying vec2 TexCoordOut_UV;
    

    
uniform mat4 Projection;
    
uniform mat4 Modelview;
    

    
void main()
    
{
    
    gl_Position = Projection * Modelview * Position;
    
    TexCoordOut = TexCoordIn;
    
}
    

    

    

    
uniform sampler2D sampler0; // Y Texture Sampler
    
uniform sampler2D sampler1; // U Texture Sampler
    
uniform sampler2D sampler2; // V Texture Sampler
    

    
varying highp vec2 TexCoordOut;
    

    
void main()
    
{
    
    highp float y = texture2D(sampler0, TexCoordOut).r;
    
    highp float u = texture2D(sampler2, TexCoordOut).r - 0.5;
    
    highp float v = texture2D(sampler1, TexCoordOut).r - 0.5;
    

    
    //y = 0.0;
    
    //u = 0.0;
    
    //v = 0.0;
    

    
    highp float r = y + 1.13983 * v;
    
    highp float g = y - 0.39465 * u - 0.58060 * v;
    
    highp float b = y + 2.03211 * u;
    

    
    gl_FragColor = vec4(r, g, b, 1.0);
    
}

    Y Texture (Grayscale) is correct but U & V has a lot of Green Color.
    So final RGB image (Y+U+V) has a lot of GREEN Color.
    What's the problem ?

    Please help.
    thanks.

  • libaomenc : Add support for tiles

    23 octobre 2018, par Mark Thompson
    libaomenc : Add support for tiles

    Adds an option to specify the number of tile rows and columns, then uses
    
a uniform tiling if possible and otherwise a fixed tiling with equal-sized
    
tiles to fill the frame.
    

    Also adds -tile-columns and -tile-rows options to make tilings with
    
power-of-two numbers of tiles, matching the behaviour of the libvpx/VP9
    
encoder.
    • [DH] libavcodec/libaomenc.c

  • exporting ogg videos from video slideshow (mp4) and audio (wav) using ffmpeg in python

    17 septembre 2018, par jtz

    I have tried to find a solution already, but just cannot make it work. I want to export an .ogg-video by combining a video slideshow (mp4) with an audio file (wav) by using ffmpeg in python. The audio is shorter than the video and should have an offset of 2000 milliseconds, so that it starts approximately in the middle of the video. The code that I tried is essentially this :

    subprocess.call(’ffmpeg.exe -itsoffset 0 -i slideshows/slideshow.mp4 -itsoffset 2000 -i sounds/audio.wav -codec:v libtheora -codec:a libvorbis output.ogg’, shell= True)

    FYI : I need to create a couple of different video formats from the video and audio input, so substituting the ogg with a different format is no option. I have already successfully created .mp4-video-files and .webm-video-files from the material, but need the .ogg in addition. Also, Power Point does not like any of the exported videos, maybe this might be relevant for finding the problem here (I also unsuccessfully tried to fix this issue).

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