Filter SDK/CInvertNeg - Revision history

Admin at 22:43, 13 January 2017

2017-01-13T22:43:53Z

Admin: /* Line by line breakdown */

2017-01-13T22:30:28Z

‎Line by line breakdown

Admin at 22:28, 13 January 2017

2017-01-13T22:28:07Z

Admin at 22:31, 12 January 2017

2017-01-12T22:31:26Z

Admin at 21:48, 12 January 2017

2017-01-12T21:48:35Z

Admin at 21:48, 12 January 2017

2017-01-12T21:48:01Z

Admin at 18:55, 29 December 2016

2016-12-29T18:55:10Z

Admin at 18:51, 29 December 2016

2016-12-29T18:51:14Z

Admin at 18:40, 29 December 2016

2016-12-29T18:40:17Z

Admin at 21:57, 28 December 2016

2016-12-28T21:57:39Z

@@ Line 205: / Line 205: @@
      return v;
-Finally we return. "v" is either an error or the new clip.
+Finally we return our new clip. We could also have returned an error instead (instead of returning an error right away).
   const char* AVSC_CC avisynth_c_plugin_init(AVS_ScriptEnvironment * env)

@@ Line 78: / Line 78: @@
 This header declares all the classes and miscellaneous constants that you might need when writing a plugin. All external plugins should #include it.
-External plugins do not link with avisynth.dll, so they can't directly access functions that are defined in the main Avisynth source code. Therefore, every important function in avisynth_c.h is either defined inline or declared as virtual (???). The virtual functions act as callbacks for external DLLs.
+External plugins do not link with avisynth.dll, so they can't directly access functions that are defined in the main Avisynth source code. Therefore, every important function in avisynth_c.h is either defined inline or (???).
   AVS_VideoFrame* AVSC_CC InvertNeg_get_frame(AVS_FilterInfo* fi, int n)

@@ Line 47: / Line 47: @@
      if (!avs_is_planar(&fi->vi) || !avs_is_yuv(&fi->vi)) {
-        v = avs_new_value_error("InvertNeg: planar YUV data only!");
+        return avs_new_value_error("InvertNeg: planar YUV data only!");
-    } else {
-       fi->get_frame = InvertNeg_get_frame;
-       v = avs_new_value_clip(new_clip);
+     }
      avs_release_clip(new_clip);
@@ Line 185: / Line 186: @@
      if (!avs_is_planar(&fi->vi) || !avs_is_yuv(&fi->vi)) {
-        v = avs_new_value_error("InvertNeg: planar YUV data only!");
+        return avs_new_value_error("InvertNeg: planar YUV data only!");
-     } else {
-Our filter will not work unless the video is stored as YUV planar. If this is not the case than an error is returned. This is done be setting the return value to an error condition.
+Our filter will not work unless the video is stored as YUV planar. If this is not the case than an error is returned.
-       fi->get_frame = InvertNeg_get_frame;
+    fi->get_frame = InvertNeg_get_frame;
-Here we are setting the get_frame callback. There are other callbacks but since "store_child" was set we do not have to worry about implementing all of them.
+Here we are setting the get_frame callback. There are other callbacks (like get_audio, set_cache_hints and get_parity), but since "store_child" was set to true we do not have to worry about implementing all of them. Just the ones we need.
-       v = avs_new_value_clip(new_clip);
+    v = avs_new_value_clip(new_clip);
-The return value is then set to the new clip returned by avs_new_c_filter. avs_new_value_clip converts the clip info an AVS_Value (???). It also creates a new reference to the clip.
+The return value is then set to the new clip returned by avs_new_c_filter. avs_new_value_clip stores the clip in an AVS_Value which will be returned by our Create_InvertNeg. It also creates a new reference to the clip.
      avs_release_clip(new_clip);

@@ Line 200: / Line 200: @@
      avs_release_clip(new_clip);
-We must now release the clip returned by avs_new_c_filter. In the case of an error the clip is no longer needed. Otherwise a new reference is created to the clip with avs_new_value_clip so we must release the orignal reference.
+We must now release the clip returned by avs_new_c_filter. In the case of an error the clip is no longer needed. Otherwise a new reference is created to the clip with avs_new_value_clip so we must release the original reference.
      return v;

← Older revision		Revision as of 21:48, 12 January 2017
Line 293:		Line 293:
	[http://www.kevina.org/avisynth_c/example.html Kevin's AviSynth C API Docs] is the documentation written for the deprecated avisynth_c.dll by Kevin Atkinson, in its original form.		[http://www.kevina.org/avisynth_c/example.html Kevin's AviSynth C API Docs] is the documentation written for the deprecated avisynth_c.dll by Kevin Atkinson, in its original form.

−	~~[[Category:FilterSDK]]~~
	[[Category:C API]]		[[Category:C API]]

← Older revision		Revision as of 21:48, 12 January 2017
Line 292:		Line 292:

	[http://www.kevina.org/avisynth_c/example.html Kevin's AviSynth C API Docs] is the documentation written for the deprecated avisynth_c.dll by Kevin Atkinson, in its original form.		[http://www.kevina.org/avisynth_c/example.html Kevin's AviSynth C API Docs] is the documentation written for the deprecated avisynth_c.dll by Kevin Atkinson, in its original form.
		+
		+	[[Category:FilterSDK]]
		+	[[Category:C API]]

@@ Line 182: / Line 182: @@
      AVS_Clip* new_clip = avs_new_c_filter(env, &fi, avs_array_elt(args, 0), 1);
-"avs_new_c_filter" creates a new filter. AVS_Clip is an abstract type representing a filter. In this case it will represent our new filter. "env" is the current script environment. "fi" will be set to point to our filter AVS_FilterInfo which is the concrete representation of a C filter. We will modify this structure later. "avs_array_elt(args, 0)" is accessing the first value of args, which is generally the parent clip. The last paramater, is a boolean value "store_child". It should generally always be set to true.
+"avs_new_c_filter" creates a new filter. AVS_Clip is an abstract type representing a filter. In this case it will represent our new filter. "env" is the current script environment. "fi" will be set to point to our filter AVS_FilterInfo which is the concrete representation of a C filter. We will modify this structure later. "avs_array_elt(args, 0)" is accessing the first value of args, which is generally the parent clip. The last parameter, is a boolean value "store_child". It should generally always be set to true.
      if (!avs_is_planar(&fi->vi) || !avs_is_yuv(&fi->vi)) {

@@ Line 163: / Line 163: @@
      return dst;
-Finally we return the dest video frame.
+GetFrame returns the newly-created frame.
   AVS_Value AVSC_CC Create_InvertNeg(AVS_ScriptEnvironment* env, AVS_Value args, void* user_data)

@@ Line 63: / Line 63: @@
+  }
-Compile this file into a DLL named InvertNeg.dll. See [[Filter_SDK/Compiling_instructions|compiling instructions]]. Now create an Avisynth script which looks something like this:
+Link to avisynth.lib and when using the MSVC++ compiler add the definition file. Compile this file into a DLL named InvertNeg.dll. See [[Filter_SDK/Compiling_instructions|compiling instructions]]. Now create an Avisynth script which looks something like this:
   LoadCPlugin("d:\path\InvertNeg.dll")