Fixed the YUY2 shaders to support scaling. The new solution has cleaner shader code and texture upload uses a better format for OpenGL.
Signed-off-by: Bård Eirik Winther <bwint...@cisco.com> --- utils/qv4l2/capture-win-gl.cpp | 68 ++++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 33 deletions(-) diff --git a/utils/qv4l2/capture-win-gl.cpp b/utils/qv4l2/capture-win-gl.cpp index c499f1f..6071410 100644 --- a/utils/qv4l2/capture-win-gl.cpp +++ b/utils/qv4l2/capture-win-gl.cpp @@ -1,5 +1,5 @@ /* - * The YUY2 shader code was copied and simplified from face-responder. The code is under public domain: + * The YUY2 shader code is based on face-responder. The code is under public domain: * https://bitbucket.org/nateharward/face-responder/src/0c3b4b957039d9f4bf1da09b9471371942de2601/yuv42201_laplace.frag?at=master * * All other OpenGL code: @@ -446,47 +446,51 @@ QString CaptureWinGLEngine::shader_YUY2_invariant(__u32 format) { switch (format) { case V4L2_PIX_FMT_YUYV: - return QString("y = (luma_chroma.r - 0.0625) * 1.1643;" - "if (mod(xcoord, 2.0) == 0.0) {" - " u = luma_chroma.a;" - " v = texture2D(tex, vec2(pixelx + texl_w, pixely)).a;" + return QString("if (mod(xcoord, 2.0) == 0.0) {" + " luma_chroma = texture2D(tex, vec2(pixelx, pixely));" + " y = (luma_chroma.r - 0.0625) * 1.1643;" "} else {" - " v = luma_chroma.a;" - " u = texture2D(tex, vec2(pixelx - texl_w, pixely)).a;" + " luma_chroma = texture2D(tex, vec2(pixelx - texl_w, pixely));" + " y = (luma_chroma.b - 0.0625) * 1.1643;" "}" + "u = luma_chroma.g - 0.5;" + "v = luma_chroma.a - 0.5;" ); case V4L2_PIX_FMT_YVYU: - return QString("y = (luma_chroma.r - 0.0625) * 1.1643;" - "if (mod(xcoord, 2.0) == 0.0) {" - " v = luma_chroma.a;" - " u = texture2D(tex, vec2(pixelx + texl_w, pixely)).a;" + return QString("if (mod(xcoord, 2.0) == 0.0) {" + " luma_chroma = texture2D(tex, vec2(pixelx, pixely));" + " y = (luma_chroma.r - 0.0625) * 1.1643;" "} else {" - " u = luma_chroma.a;" - " v = texture2D(tex, vec2(pixelx - texl_w, pixely)).a;" + " luma_chroma = texture2D(tex, vec2(pixelx - texl_w, pixely));" + " y = (luma_chroma.b - 0.0625) * 1.1643;" "}" + "u = luma_chroma.a - 0.5;" + "v = luma_chroma.g - 0.5;" ); case V4L2_PIX_FMT_UYVY: - return QString("y = (luma_chroma.a - 0.0625) * 1.1643;" - "if (mod(xcoord, 2.0) == 0.0) {" - " u = luma_chroma.r;" - " v = texture2D(tex, vec2(pixelx + texl_w, pixely)).r;" + return QString("if (mod(xcoord, 2.0) == 0.0) {" + " luma_chroma = texture2D(tex, vec2(pixelx, pixely));" + " y = (luma_chroma.g - 0.0625) * 1.1643;" "} else {" - " v = luma_chroma.r;" - " u = texture2D(tex, vec2(pixelx - texl_w, pixely)).r;" + " luma_chroma = texture2D(tex, vec2(pixelx - texl_w, pixely));" + " y = (luma_chroma.a - 0.0625) * 1.1643;" "}" + "u = luma_chroma.r - 0.5;" + "v = luma_chroma.b - 0.5;" ); case V4L2_PIX_FMT_VYUY: - return QString("y = (luma_chroma.a - 0.0625) * 1.1643;" - "if (mod(xcoord, 2.0) == 0.0) {" - " v = luma_chroma.r;" - " u = texture2D(tex, vec2(pixelx + texl_w, pixely)).r;" + return QString("if (mod(xcoord, 2.0) == 0.0) {" + " luma_chroma = texture2D(tex, vec2(pixelx, pixely));" + " y = (luma_chroma.g - 0.0625) * 1.1643;" "} else {" - " u = luma_chroma.r;" - " v = texture2D(tex, vec2(pixelx - texl_w, pixely)).r;" + " luma_chroma = texture2D(tex, vec2(pixelx - texl_w, pixely));" + " y = (luma_chroma.a - 0.0625) * 1.1643;" "}" + "u = luma_chroma.b - 0.5;" + "v = luma_chroma.r - 0.5;" ); default: @@ -499,8 +503,8 @@ void CaptureWinGLEngine::shader_YUY2(__u32 format) m_screenTextureCount = 1; glGenTextures(m_screenTextureCount, m_screenTexture); configureTexture(0); - glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE_ALPHA, m_frameWidth, m_frameHeight, 0, - GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, NULL); + glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, m_frameWidth / 2, m_frameHeight, 0, + GL_RGBA, GL_UNSIGNED_BYTE, NULL); checkError("YUY2 shader"); QString codeHead = QString("uniform sampler2D tex;" @@ -509,17 +513,15 @@ void CaptureWinGLEngine::shader_YUY2(__u32 format) "void main()" "{" " float y, u, v;" + " vec4 luma_chroma;" " float pixelx = gl_TexCoord[0].x;" " float pixely = gl_TexCoord[0].y;" " float xcoord = floor(pixelx * tex_w);" - " vec4 luma_chroma = texture2D(tex, vec2(pixelx, pixely));" ); QString codeBody = shader_YUY2_invariant(format); - QString codeTail = QString(" u = u - 0.5;" - " v = v - 0.5;" - " float r = y + 1.5958 * v;" + QString codeTail = QString(" float r = y + 1.5958 * v;" " float g = y - 0.39173 * u - 0.81290 * v;" " float b = y + 2.017 * u;" " gl_FragColor = vec4(r, g, b, 1.0);" @@ -548,8 +550,8 @@ void CaptureWinGLEngine::render_YUY2() glBindTexture(GL_TEXTURE_2D, m_screenTexture[0]); GLint Y = m_glfunction.glGetUniformLocation(m_shaderProgram.programId(), "tex"); glUniform1i(Y, 0); - glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_frameWidth, m_frameHeight, - GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, m_frameData); + glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_frameWidth / 2, m_frameHeight, + GL_RGBA, GL_UNSIGNED_BYTE, m_frameData); checkError("YUY2 paint"); } #endif -- 1.8.4.rc1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
