[FFmpeg-devel] [PATCH] memcpy-less expand

Michael Tison blackspike
Thu Sep 17 23:54:27 CEST 2009


Here's an attempt at the memcpy-less expand. I implemented a
get_video_buffer for the input pad that'll hand a correctly sized
buffer to the previous filter.

I tried to do it without changing the api too much but still changed
one line in avfilter.c so that when srcpic is copied it is copied into
a correctly sized buffer.

Thanks!

Michael
-------------- next part --------------
Index: allfilters.c
===================================================================
--- allfilters.c	(revision 5387)
+++ allfilters.c	(working copy)
@@ -36,6 +36,7 @@ void avfilter_register_all(void)
 
     REGISTER_FILTER(CROP,crop,vf);
     REGISTER_FILTER(DRAWBOX,drawbox,vf);
+    REGISTER_FILTER(EXPAND,expand,vf);
     REGISTER_FILTER(FIFO,fifo,vf);
     REGISTER_FILTER(FORMAT,format,vf);
     REGISTER_FILTER(FPS,fps,vf);
Index: vf_expand.c
===================================================================
--- vf_expand.c	(revision 0)
+++ vf_expand.c	(revision 0)
@@ -0,0 +1,216 @@
+/*
+ * Expand Video Filter
+ * Copyright (c) 2009 Michael Tison
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavcodec/imgconvert.h"
+#include "avfilter.h"
+
+typedef struct {
+    int w0, h0;       //< original width and height (w,h)
+    int dw, dh;       //< difference between original w,h and new w,h
+    int x, y;         //< top left corner of image in padding
+    int hsub, vsub;   //< chroma subsampling
+} ExpContext;
+
+static av_cold int init(AVFilterContext *c, const char *args, void *opaque) {
+    ExpContext *exp = c->priv;
+
+    exp->dh = 0;
+    exp->dw = 0;
+    exp->x  = -1;
+    exp->y  = -1;
+
+    if(args)
+        sscanf(args, "%d:%d:%d:%d", &exp->dw, &exp->dh, &exp->x, &exp->y);
+
+    return 0;
+}
+
+static int config_props_input(AVFilterLink *link) {
+    ExpContext *exp = link->dst->priv;
+
+    exp->h0 = link->h;
+    exp->w0 = link->w;
+    if(exp->x < 0)      exp->x = exp->dw / 2;
+    if(exp->y < 0)      exp->y = exp->dh / 2;
+
+    avcodec_get_chroma_sub_sample(link->format, &exp->hsub, &exp->vsub);
+    av_log(NULL, AV_LOG_INFO, "in %s"  
+           " and exp->h0=%d, exp->w0=%d\n", __FUNCTION__, exp->h0, exp->w0); 
+    return 0;
+}
+
+static void free_video_buffer(AVFilterPic *pic) {
+    av_free(pic->data[0]);
+    av_free(pic);
+}
+
+static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms) {
+    ExpContext *exp     = link->dst->priv;
+    AVFilterPic *pic    = av_mallocz(sizeof(AVFilterPic));
+    AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
+    int i, tempsize;
+    uint8_t *buf;
+
+    ref->pic = pic;
+    ref->w   = link->w;
+    ref->h   = link->h;
+
+    ref->perms = perms | AV_PERM_READ | AV_PERM_WRITE;
+
+    pic->refcount = 1;
+    pic->format   = link->format;
+    pic->free     = free_video_buffer;
+    ff_fill_linesize((AVPicture *)pic, pic->format, ref->w + exp->dw);
+
+    for (i=0; i<4;i++)
+        pic->linesize[i] = FFALIGN(pic->linesize[i], 16);
+
+    tempsize = ff_fill_pointer((AVPicture *)pic, NULL, pic->format, ref->h + exp->dh);
+    buf      = av_mallocz(tempsize);
+    ff_fill_pointer((AVPicture *)pic, buf, pic->format, ref->h + exp->dh);
+
+    memcpy(ref->data,     pic->data,        sizeof(pic->data));
+    memcpy(ref->linesize, pic->linesize,    sizeof(pic->linesize));
+
+    return ref;
+}
+
+static int query_formats(AVFilterContext *ctx) {
+    avfilter_set_common_formats(ctx,
+        avfilter_make_format_list(10,
+                PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P,
+                PIX_FMT_YUV411P,  PIX_FMT_YUV410P,
+                PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
+                PIX_FMT_YUV440P,  PIX_FMT_YUVJ440P));
+    return 0;
+}
+
+static int config_props_output(AVFilterLink *link) {
+    ExpContext *exp = link->src->priv;
+
+    link->w = link->src->inputs[0]->w + exp->dw;
+    link->h = link->src->inputs[0]->h + exp->dh;
+
+    return 0;
+}
+
+static void start_frame(AVFilterLink *link, AVFilterPicRef *picref) {
+    ExpContext *exp      = link->dst->priv;
+    AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
+    AVFilterPicRef *tmp_ref;
+    int i;
+
+    ref2->w = exp->w0 + exp->dw;
+    ref2->h = exp->h0 + exp->dh;
+
+    ff_fill_linesize((AVPicture*)ref2->pic, ref2->pic->format,  ref2->w);
+    for (i=0; i<4;i++)
+        ref2->pic->linesize[i] = FFALIGN(ref2->pic->linesize[i], 16);
+    ff_fill_pointer((AVPicture*)ref2->pic,  ref2->pic->data[0], ref2->pic->format, ref2->h);
+
+    memcpy(ref2->linesize, ref2->pic->linesize, sizeof(ref2->pic->linesize));
+    memcpy(ref2->data,     ref2->pic->data,     sizeof(ref2->pic->data));
+
+    avfilter_start_frame(link->dst->outputs[0], ref2);
+}
+
+static inline int in_region(int in_x, int in_y, int hsub, int vsub, ExpContext *exp) {
+    if(in_x >> hsub >= exp->x >> hsub
+       && in_x >> hsub < (exp->x + exp->w0) >> hsub
+       && in_y >> vsub > exp->y >> vsub
+       && in_y >> vsub < (exp->y + exp->h0) >> vsub) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+static void draw_expanded_pic(AVFilterPicRef *pic, ExpContext *exp) {
+    uint8_t *row;
+    int i, j, plane, vsub, hsub, max_h, max_w, c;
+    int xoff, yoff;   //< (x,y)offset
+   
+    xoff = exp->x;
+    yoff = exp->y;    
+
+    for(i=0; i<4; i++) 
+        pic->data[i] = pic->pic->data[i];
+    for(i=0; i<4; i++)
+        pic->linesize[i] = pic->pic->linesize[i];
+
+    for(plane = 0; plane < 3; plane++) {
+        c    = (plane == 0) ? 0 : 128;
+        hsub = (plane == 0) ? 0 : exp->hsub;
+        vsub = (plane == 0) ? 0 : exp->vsub;
+        max_h = exp->h0 + exp->dh - 1;
+        max_w = exp->w0 + exp->dw;
+
+        row = pic->data[plane] + (max_h >> vsub)*pic->linesize[plane]; 
+        for(j = max_h >> vsub; j >= 0; j--) {
+            for(i = max_w >> hsub; i >= 0; i--) {
+                if(in_region(i<<hsub, j<<vsub, hsub, vsub, exp)) 
+                    row[i] = *(pic->data[plane] + i + j*pic->linesize[plane] 
+                               - (xoff >> hsub) - (yoff >> vsub)*pic->linesize[plane]);
+                else 
+                    row[i] = c;
+            }
+            
+            row -= pic->linesize[plane];
+        }
+    }
+}
+
+static void end_frame(AVFilterLink *link) {
+    ExpContext *exp = link->dst->priv;
+    AVFilterLink *output = link->dst->outputs[0];
+    AVFilterPicRef *pic = link->cur_pic;
+
+    draw_expanded_pic(pic, exp);
+
+    avfilter_draw_slice(output, 0, pic->h);
+    avfilter_end_frame(output);
+    avfilter_unref_pic(link->cur_pic);
+    link->cur_pic = NULL;
+}
+
+AVFilter avfilter_vf_expand =
+{
+    .name      = "expand",
+    .priv_size = sizeof(ExpContext),
+    .query_formats = query_formats,
+    .init      = init,
+    .inputs    = (AVFilterPad[]) {{ .name            = "default",
+                                    .type            = CODEC_TYPE_VIDEO,
+                                    .start_frame     = start_frame,
+                                    .get_video_buffer= get_video_buffer,
+                                    .end_frame       = end_frame,
+                                    .config_props    = config_props_input,
+                                    .min_perms       = AV_PERM_READ |
+                                                       AV_PERM_WRITE,
+                                    .rej_perms       = AV_PERM_WRITE |  // Force the previous filter to ask for a new buffer...
+                                                       AV_PERM_REUSE |
+                                                       AV_PERM_REUSE2},
+                                  { .name = NULL}},
+    .outputs   = (AVFilterPad[]) {{ .name            = "default",
+                                    .config_props    = config_props_output,
+                                    .type            = CODEC_TYPE_VIDEO, },
+                                  { .name = NULL}},
+};
Index: Makefile
===================================================================
--- Makefile	(revision 5387)
+++ Makefile	(working copy)
@@ -16,6 +16,7 @@ OBJS = allfilters.o \
 
 OBJS-$(CONFIG_CROP_FILTER)       += vf_crop.o
 OBJS-$(CONFIG_DRAWBOX_FILTER)    += vf_drawbox.o
+OBJS-$(CONFIG_EXPAND_FILTER)     += vf_expand.o
 OBJS-$(CONFIG_FPS_FILTER)        += vf_fps.o
 OBJS-$(CONFIG_HFLIP_FILTER)      += vf_hflip.o
 OBJS-$(CONFIG_NEGATE_FILTER)     += vf_negate.o
-------------- next part --------------
Index: libavfilter/avfilter.c
===================================================================
--- libavfilter/avfilter.c	(revision 19868)
+++ libavfilter/avfilter.c	(working copy)
@@ -218,7 +218,7 @@ void avfilter_start_frame(AVFilterLink *link, AVFi
                 link_dpad(link).min_perms, link_dpad(link).rej_perms);
         */
 
-        link->cur_pic = avfilter_default_get_video_buffer(link, dst->min_perms);
+        link->cur_pic = avfilter_get_video_buffer(link, dst->min_perms);
         link->srcpic = picref;
         link->cur_pic->pts = link->srcpic->pts;
         link->cur_pic->pixel_aspect = link->srcpic->pixel_aspect;



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