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https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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[441/906] sobel: convolve only luma
Rework Sobel a little bit again making it work as the old one: 1. desaturate input texture 2. calculate horizontal convolution for x gradient and vertical convolution for y gradient at the same time (halves the number of needed texture lookups) 3. store results in a single texture (red and green channel) 4. calculate remaining convolution (same as above switching vertical and horizontal) 5. calculate length of gradient using red and green as x and y components. Optimize wherever possible, store kernels as constants in the shaders, remove unneeded uniforms. Restore invert property carefully avoiding using IF. Still not sure if "full color" convolution will be needed, glfiltersobel is to be intended as a demo filter and xray, the only effect which uses sobel only needs edge intensity. Dropping it for now.
This commit is contained in:
Filippo Argiolas
Matthew Waters
parent
49df4dca3c
commit
5fd66383ab
4 changed files with 112 additions and 135 deletions
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@ -308,60 +308,79 @@ const gchar *sobel_fragment_source =
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" gl_FragColor = vec4(vec3(g), 1.0);"
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"}";
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const gchar *sobel_gradient_length_fragment_source =
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"#extension GL_ARB_texture_rectangle : enable\n"
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"uniform sampler2DRect gx;"
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"uniform sampler2DRect gy;"
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"void main () {"
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" vec4 dx = texture2DRect (gx, gl_TexCoord[0].st);"
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" vec4 dy = texture2DRect (gy, gl_TexCoord[0].st);"
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" dx = (dx - 0.5);"
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" dy = (dy - 0.5);"
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" gl_FragColor = vec4(sqrt(dx*dx + dy*dy));"
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"}";
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/* horizontal convolution 3x3 */
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const gchar *hconv3_fragment_source =
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const gchar *sep_sobel_length_fragment_source =
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"#extension GL_ARB_texture_rectangle : enable\n"
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"uniform sampler2DRect tex;"
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"uniform bool invert;"
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"void main () {"
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" vec4 g = texture2DRect (tex, gl_TexCoord[0].st);"
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/* restore black background with grey edges */
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" g -= vec4(0.5, 0.5, 0.0, 0.0);"
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" float len = length (g);"
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/* little trick to avoid IF operator */
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/* TODO: test if a standalone inverting pass is worth */
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" gl_FragColor = abs(int(invert) - vec4(vec3(len), 1.0));"
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"}";
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const gchar *desaturate_fragment_source =
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"#extension GL_ARB_texture_rectangle : enable\n"
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"uniform sampler2DRect tex;"
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"void main () {"
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" vec4 color = texture2DRect (tex, gl_TexCoord[0].st);"
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" float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));"
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" gl_FragColor = vec4(vec3(luma), color.a);"
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"}";
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const gchar *sep_sobel_hconv3_fragment_source =
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"#extension GL_ARB_texture_rectangle : enable\n"
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"uniform sampler2DRect tex;"
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"uniform float kernel[3];"
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"uniform float offset;"
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"void main () {"
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" vec2 texturecoord[3];"
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" float s = gl_TexCoord[0].s;"
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" float t = gl_TexCoord[0].t;"
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" texturecoord[0] = vec2(s-1.0, t);"
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" texturecoord[1] = vec2(s, t);"
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" texturecoord[2] = vec2(s+1.0, t);"
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" texturecoord[1] = gl_TexCoord[0].st;"
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" texturecoord[0] = texturecoord[1] - vec2(1.0, 0.0);"
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" texturecoord[2] = texturecoord[1] + vec2(1.0, 0.0);"
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" float grad_kern[3];"
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" grad_kern[0] = 1.0;"
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" grad_kern[1] = 0.0;"
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" grad_kern[2] = -1.0;"
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" float blur_kern[3];"
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" blur_kern[0] = 0.25;"
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" blur_kern[1] = 0.5;"
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" blur_kern[2] = 0.25;"
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" int i;"
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" vec4 sum = vec4 (0.0);"
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" for (i = 0; i < 3; i++) { "
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" vec4 neighbor = texture2DRect(tex, texturecoord[i]); "
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" sum += neighbor * kernel[i];"
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" sum.r = neighbor.r * blur_kern[i] + sum.r;"
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" sum.g = neighbor.g * grad_kern[i] + sum.g;"
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" }"
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" gl_FragColor = sum + offset;"
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" gl_FragColor = sum + vec4(0.0, 0.5, 0.0, 0.0);"
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"}";
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/* vertical convolution 3x3 */
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const gchar *vconv3_fragment_source =
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const gchar *sep_sobel_vconv3_fragment_source =
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"#extension GL_ARB_texture_rectangle : enable\n"
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"uniform sampler2DRect tex;"
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"uniform float kernel[3];"
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"uniform float offset;"
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"void main () {"
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" vec2 texturecoord[3];"
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" float s = gl_TexCoord[0].s;"
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" float t = gl_TexCoord[0].t;"
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" texturecoord[0] = vec2(s, t-1.0);"
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" texturecoord[1] = vec2(s, t);"
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" texturecoord[2] = vec2(s, t+1.0);"
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" texturecoord[1] = gl_TexCoord[0].st;"
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" texturecoord[0] = texturecoord[1] - vec2(0.0, 1.0);"
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" texturecoord[2] = texturecoord[1] + vec2(0.0, 1.0);"
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" float grad_kern[3];"
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" grad_kern[0] = 1.0;"
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" grad_kern[1] = 0.0;"
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" grad_kern[2] = -1.0;"
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" float blur_kern[3];"
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" blur_kern[0] = 0.25;"
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" blur_kern[1] = 0.5;"
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" blur_kern[2] = 0.25;"
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" int i;"
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" vec4 sum = vec4 (0.0);"
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" for (i = 0; i < 3; i++) { "
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" vec4 neighbor = texture2DRect(tex, texturecoord[i]);"
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" sum += neighbor * kernel[i]; "
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" vec4 neighbor = texture2DRect(tex, texturecoord[i]); "
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" sum.r = neighbor.r * grad_kern[i] + sum.r;"
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" sum.g = neighbor.g * blur_kern[i] + sum.g;"
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" }"
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" gl_FragColor = sum + offset;"
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" gl_FragColor = sum + vec4(0.5, 0.0, 0.0, 0.0);"
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"}";
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/* horizontal convolution 9x9 */
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@ -33,9 +33,10 @@ extern const gchar *bulge_fragment_source;
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extern const gchar *square_fragment_source;
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extern const gchar *luma_threshold_fragment_source;
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extern const gchar *sobel_fragment_source;
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extern const gchar *sobel_gradient_length_fragment_source;
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extern const gchar *hconv3_fragment_source;
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extern const gchar *vconv3_fragment_source;
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extern const gchar *sep_sobel_length_fragment_source;
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extern const gchar *desaturate_fragment_source;
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extern const gchar *sep_sobel_hconv3_fragment_source;
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extern const gchar *sep_sobel_vconv3_fragment_source;
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extern const gchar *hconv9_fragment_source;
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extern const gchar *vconv9_fragment_source;
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extern const gchar *sum_fragment_source;
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@ -65,24 +65,15 @@ static void gst_gl_filtersobel_draw_texture (GstGLFilterSobel * filtersobel,
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static void gst_gl_filtersobel_init_shader (GstGLFilter * filter);
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static gboolean gst_gl_filtersobel_filter (GstGLFilter * filter,
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GstGLBuffer * inbuf, GstGLBuffer * outbuf);
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static void gst_gl_filtersobel_step_one (gint width, gint height, guint texture,
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gpointer stuff);
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static void gst_gl_filtersobel_step_two (gint width, gint height, guint texture,
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gpointer stuff);
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static void gst_gl_filtersobel_step_three (gint width, gint height,
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guint texture, gpointer stuff);
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static void gst_gl_filtersobel_step_four (gint width, gint height,
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guint texture, gpointer stuff);
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static void gst_gl_filtersobel_step_five (gint width, gint height,
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guint texture, gpointer stuff);
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static gfloat grad_kern[3] = {
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1.0, 0.0, -1.0,
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};
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static gfloat blur_kern[3] = {
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1.0 / 4.0, 2.0 / 4.0, 1.0 / 4.0,
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};
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static void gst_gl_filtersobel_desaturate (gint width, gint height,
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guint texture, gpointer stuff);
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static void gst_gl_filtersobel_hconv (gint width, gint height, guint texture,
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gpointer stuff);
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static void gst_gl_filtersobel_vconv (gint width, gint height, guint texture,
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gpointer stuff);
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static void gst_gl_filtersobel_length (gint width, gint height, guint texture,
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gpointer stuff);
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static void
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gst_gl_filtersobel_init_resources (GstGLFilter * filter)
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@ -90,7 +81,7 @@ gst_gl_filtersobel_init_resources (GstGLFilter * filter)
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
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int i;
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for (i = 0; i < 5; i++) {
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for (i = 0; i < 2; i++) {
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glGenTextures (1, &filtersobel->midtexture[i]);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, filtersobel->midtexture[i]);
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glTexImage2D (GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA8,
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@ -112,7 +103,7 @@ gst_gl_filtersobel_reset_resources (GstGLFilter * filter)
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
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int i;
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for (i = 0; i < 5; i++) {
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for (i = 0; i < 2; i++) {
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glDeleteTextures (1, &filtersobel->midtexture[i]);
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}
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}
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@ -160,7 +151,7 @@ gst_gl_filtersobel_init (GstGLFilterSobel * filtersobel,
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filtersobel->hconv = NULL;
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filtersobel->vconv = NULL;
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filtersobel->invert = FALSE;
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for (i = 0; i < 5; i++) {
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for (i = 0; i < 2; i++) {
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filtersobel->midtexture[i] = 0;
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}
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}
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@ -171,6 +162,7 @@ gst_gl_filter_filtersobel_reset (GstGLFilter * filter)
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
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//blocking call, wait the opengl thread has destroyed the shader
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gst_gl_display_del_shader (filter->display, filtersobel->desat);
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gst_gl_display_del_shader (filter->display, filtersobel->hconv);
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gst_gl_display_del_shader (filter->display, filtersobel->vconv);
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gst_gl_display_del_shader (filter->display, filtersobel->len);
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@ -214,12 +206,14 @@ gst_gl_filtersobel_init_shader (GstGLFilter * filter)
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
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//blocking call, wait the opengl thread has compiled the shader
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gst_gl_display_gen_shader (filter->display, 0, hconv3_fragment_source,
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&filtersobel->hconv);
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gst_gl_display_gen_shader (filter->display, 0, vconv3_fragment_source,
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&filtersobel->vconv);
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gst_gl_display_gen_shader (filter->display, 0, desaturate_fragment_source,
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&filtersobel->desat);
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gst_gl_display_gen_shader (filter->display, 0,
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sobel_gradient_length_fragment_source, &filtersobel->len);
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sep_sobel_hconv3_fragment_source, &filtersobel->hconv);
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gst_gl_display_gen_shader (filter->display, 0,
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sep_sobel_vconv3_fragment_source, &filtersobel->vconv);
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gst_gl_display_gen_shader (filter->display, 0,
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sep_sobel_length_fragment_source, &filtersobel->len);
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}
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static void
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@ -252,21 +246,39 @@ gst_gl_filtersobel_filter (GstGLFilter * filter, GstGLBuffer * inbuf,
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
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gst_gl_filter_render_to_target (filter, inbuf->texture,
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filtersobel->midtexture[0], gst_gl_filtersobel_step_one, filtersobel);
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filtersobel->midtexture[0], gst_gl_filtersobel_desaturate, filtersobel);
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gst_gl_filter_render_to_target (filter, filtersobel->midtexture[0],
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filtersobel->midtexture[1], gst_gl_filtersobel_step_two, filtersobel);
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gst_gl_filter_render_to_target (filter, inbuf->texture,
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filtersobel->midtexture[2], gst_gl_filtersobel_step_three, filtersobel);
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gst_gl_filter_render_to_target (filter, filtersobel->midtexture[2],
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filtersobel->midtexture[3], gst_gl_filtersobel_step_four, filtersobel);
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gst_gl_filter_render_to_target (filter, filtersobel->midtexture[3],
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outbuf->texture, gst_gl_filtersobel_step_five, filtersobel);
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filtersobel->midtexture[1], gst_gl_filtersobel_hconv, filtersobel);
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gst_gl_filter_render_to_target (filter, filtersobel->midtexture[1],
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filtersobel->midtexture[0], gst_gl_filtersobel_vconv, filtersobel);
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gst_gl_filter_render_to_target (filter, filtersobel->midtexture[0],
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outbuf->texture, gst_gl_filtersobel_length, filtersobel);
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return TRUE;
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}
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static void
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gst_gl_filtersobel_step_one (gint width, gint height, guint texture,
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gst_gl_filtersobel_desaturate (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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glMatrixMode (GL_PROJECTION);
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glLoadIdentity ();
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gst_gl_shader_use (filtersobel->desat);
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glActiveTexture (GL_TEXTURE1);
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glEnable (GL_TEXTURE_RECTANGLE_ARB);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->desat, "tex", 1);
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gst_gl_filtersobel_draw_texture (filtersobel, texture);
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}
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static void
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gst_gl_filtersobel_hconv (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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@ -282,14 +294,12 @@ gst_gl_filtersobel_step_one (gint width, gint height, guint texture,
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->hconv, "tex", 1);
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gst_gl_shader_set_uniform_1fv (filtersobel->hconv, "kernel", 3, blur_kern);
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gst_gl_shader_set_uniform_1f (filtersobel->hconv, "offset", 0.0);
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gst_gl_filtersobel_draw_texture (filtersobel, texture);
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}
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static void
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gst_gl_filtersobel_step_two (gint width, gint height, guint texture,
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gst_gl_filtersobel_vconv (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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@ -305,60 +315,12 @@ gst_gl_filtersobel_step_two (gint width, gint height, guint texture,
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->vconv, "tex", 1);
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gst_gl_shader_set_uniform_1fv (filtersobel->vconv, "kernel", 3, grad_kern);
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gst_gl_shader_set_uniform_1f (filtersobel->vconv, "offset", 0.5);
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gst_gl_filtersobel_draw_texture (filtersobel, texture);
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}
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static void
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gst_gl_filtersobel_step_three (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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glMatrixMode (GL_PROJECTION);
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glLoadIdentity ();
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gst_gl_shader_use (filtersobel->vconv);
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glActiveTexture (GL_TEXTURE1);
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glEnable (GL_TEXTURE_RECTANGLE_ARB);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->vconv, "tex", 1);
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gst_gl_shader_set_uniform_1fv (filtersobel->vconv, "kernel", 3, blur_kern);
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gst_gl_shader_set_uniform_1f (filtersobel->vconv, "offset", 0.0);
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gst_gl_filtersobel_draw_texture (filtersobel, texture);
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}
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static void
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gst_gl_filtersobel_step_four (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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glMatrixMode (GL_PROJECTION);
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glLoadIdentity ();
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gst_gl_shader_use (filtersobel->hconv);
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glActiveTexture (GL_TEXTURE1);
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glEnable (GL_TEXTURE_RECTANGLE_ARB);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->hconv, "tex", 1);
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gst_gl_shader_set_uniform_1fv (filtersobel->hconv, "kernel", 3, grad_kern);
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gst_gl_shader_set_uniform_1f (filtersobel->vconv, "offset", 0.5);
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gst_gl_filtersobel_draw_texture (filtersobel, texture);
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}
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static void
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gst_gl_filtersobel_step_five (gint width, gint height, guint texture,
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gst_gl_filtersobel_length (gint width, gint height, guint texture,
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gpointer stuff)
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{
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GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
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@ -370,18 +332,12 @@ gst_gl_filtersobel_step_five (gint width, gint height, guint texture,
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glActiveTexture (GL_TEXTURE1);
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glEnable (GL_TEXTURE_RECTANGLE_ARB);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, filtersobel->midtexture[1]);
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glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
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glDisable (GL_TEXTURE_RECTANGLE_ARB);
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gst_gl_shader_set_uniform_1i (filtersobel->len, "gx", 1);
|
||||
|
||||
glActiveTexture (GL_TEXTURE2);
|
||||
glEnable (GL_TEXTURE_RECTANGLE_ARB);
|
||||
glBindTexture (GL_TEXTURE_RECTANGLE_ARB, filtersobel->midtexture[3]);
|
||||
glDisable (GL_TEXTURE_RECTANGLE_ARB);
|
||||
|
||||
gst_gl_shader_set_uniform_1i (filtersobel->len, "gy", 2);
|
||||
|
||||
gst_gl_shader_set_uniform_1i (filtersobel->len, "tex", 1);
|
||||
gst_gl_shader_set_uniform_1i (filtersobel->len, "invert",
|
||||
filtersobel->invert);
|
||||
|
||||
gst_gl_filtersobel_draw_texture (filtersobel, texture);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -39,6 +39,7 @@ struct _GstGLFilterSobel
|
|||
GstGLShader *hconv;
|
||||
GstGLShader *vconv;
|
||||
GstGLShader *len;
|
||||
GstGLShader *desat;
|
||||
|
||||
GLuint midtexture[5];
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue