simplifies null vhook by using sws_getCachedContext()

Patch by Victor Paesa %wzrlpy A arsystel P com%
Original thread:
Date: Sep 15, 2006 6:21 PM
Subject: Re: [Ffmpeg-devel] [PATCH] enable libswscale

Originally committed as revision 6651 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 20 insertions, 41 deletions

diff --git a/vhook/null.c b/vhook/null.c
index c92d5ffa17..041e5abda9 100644
--- a/vhook/null.c
+++ b/vhook/null.c
@@ -34,11 +34,6 @@ typedef struct {
     // ... and later converts back frame from RGB to initial format
     struct SwsContext *fromRGB_convert_ctx;
 
-    enum PixelFormat sws_pix_fmt;   // Sws_Context is opaque, we need to save
-    int sws_width, sws_height;      // this to check if we can re-use contexts
-    // Contexts will be re-used 99% of time,
-    // I know of width/height changes only in DVB broadcasts
-
 } ContextInfo;
 
 void Release(void *ctx)
@@ -79,46 +74,19 @@ void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width,
         avpicture_fill(&picture1, buf, PIX_FMT_RGB24, width, height);
 
         // if we already got a SWS context, let's realloc if is not re-useable
-        if (ci->toRGB_convert_ctx != NULL) {
-            if ((ci->sws_pix_fmt != pix_fmt) ||
-                 (ci->sws_width != width) || (ci->sws_height != height)) {
-                sws_freeContext(ci->toRGB_convert_ctx);
-                ci->toRGB_convert_ctx = NULL;
-                sws_freeContext(ci->fromRGB_convert_ctx);
-                ci->fromRGB_convert_ctx = NULL;
-            }
-        }
+        ci->toRGB_convert_ctx = sws_getCachedContext(ci->toRGB_convert_ctx,
+                                    width, height, pix_fmt,
+                                    width, height, PIX_FMT_RGB24,
+                                    sws_flags, NULL, NULL, NULL);
         if (ci->toRGB_convert_ctx == NULL) {
-            ci->sws_pix_fmt = pix_fmt;
-            ci->sws_width = width;
-            ci->sws_height = height;
-            ci->toRGB_convert_ctx = sws_getContext(
-                                             ci->sws_width, ci->sws_height,
-                                             ci->sws_pix_fmt,
-                                             ci->sws_width, ci->sws_height,
-                                             PIX_FMT_RGB24,
-                                             sws_flags, NULL, NULL, NULL);
-            if (ci->toRGB_convert_ctx == NULL) {
-                av_log(NULL, AV_LOG_ERROR,
-                       "Cannot initialize the toRGB conversion context\n");
-                exit(1);
-            }
-            ci->fromRGB_convert_ctx = sws_getContext(
-                                             ci->sws_width, ci->sws_height,
-                                             PIX_FMT_RGB24,
-                                             ci->sws_width, ci->sws_height,
-                                             ci->sws_pix_fmt,
-                                             sws_flags, NULL, NULL, NULL);
-            if (ci->fromRGB_convert_ctx == NULL) {
-                av_log(NULL, AV_LOG_ERROR,
-                       "Cannot initialize the fromRGB conversion context\n");
-                exit(1);
-            }
+            av_log(NULL, AV_LOG_ERROR,
+                   "Cannot initialize the toRGB conversion context\n");
+            exit(1);
         }
 // img_convert parameters are          2 first destination, then 4 source
 // sws_scale   parameters are context, 4 first source,      then 2 destination
         sws_scale(ci->toRGB_convert_ctx,
-            picture->data, picture->linesize, 0, ci->sws_height,
+            picture->data, picture->linesize, 0, height,
             picture1.data, picture1.linesize);
 
         pict = &picture1;
@@ -127,8 +95,19 @@ void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width,
     /* Insert filter code here */
 
     if (pix_fmt != PIX_FMT_RGB24) {
+        ci->fromRGB_convert_ctx = sws_getCachedContext(ci->fromRGB_convert_ctx,
+                                        width, height, PIX_FMT_RGB24,
+                                        width, height, pix_fmt,
+                                        sws_flags, NULL, NULL, NULL);
+        if (ci->fromRGB_convert_ctx == NULL) {
+            av_log(NULL, AV_LOG_ERROR,
+                   "Cannot initialize the fromRGB conversion context\n");
+            exit(1);
+        }
+// img_convert parameters are          2 first destination, then 4 source
+// sws_scale   parameters are context, 4 first source,      then 2 destination
         sws_scale(ci->fromRGB_convert_ctx,
-            picture1.data, picture1.linesize, 0, ci->sws_height,
+            picture1.data, picture1.linesize, 0, height,
             picture->data, picture->linesize);
     }