Add AVFilterPicRef.pos field and make libavfilter propagate stream

byte position information, as stored in the pkt.pos, through the
filterchain.

Note that the pos field is added *non* at the end of the
AVFilterPicRef struct, thus breaking ABI compatibility, which is
allowed as the API is still considered non-stable.

Originally committed as revision 22506 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfilter.c

@@ -171,11 +171,12 @@ int avfilter_config_links(AVFilterContext *filter)
 static void dprintf_picref(void *ctx, AVFilterPicRef *picref, int end)
 {
     dprintf(ctx,
-            "picref[%p data[%p, %p, %p, %p] linesize[%d, %d, %d, %d] pts:%"PRId64" a:%d/%d s:%dx%d]%s",
+            "picref[%p data[%p, %p, %p, %p] linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64" a:%d/%d s:%dx%d]%s",
             picref,
             picref->data    [0], picref->data    [1], picref->data    [2], picref->data    [3],
             picref->linesize[0], picref->linesize[1], picref->linesize[2], picref->linesize[3],
-            picref->pts, picref->pixel_aspect.num, picref->pixel_aspect.den, picref->w, picref->h,
+            picref->pts, picref->pos,
+            picref->pixel_aspect.num, picref->pixel_aspect.den, picref->w, picref->h,
             end ? "\n" : "");
 }
 
@@ -263,6 +264,7 @@ void avfilter_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
         link->cur_pic = avfilter_default_get_video_buffer(link, dst->min_perms, link->w, link->h);
         link->srcpic = picref;
         link->cur_pic->pts = link->srcpic->pts;
+        link->cur_pic->pos = link->srcpic->pos;
         link->cur_pic->pixel_aspect = link->srcpic->pixel_aspect;
     }
     else

libavfilter/avfilter.h

@@ -105,6 +105,7 @@ typedef struct AVFilterPicRef
     int h;                      ///< image height
 
     int64_t pts;                ///< presentation timestamp in units of 1/AV_TIME_BASE
+    int64_t pos;                ///< byte position in stream, -1 if unknown
 
     AVRational pixel_aspect;    ///< pixel aspect ratio
 

libavfilter/defaults.c

@@ -74,6 +74,7 @@ void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
     if(out) {
         out->outpic      = avfilter_get_video_buffer(out, AV_PERM_WRITE, out->w, out->h);
         out->outpic->pts = picref->pts;
+        out->outpic->pos = picref->pos;
         out->outpic->pixel_aspect = picref->pixel_aspect;
         avfilter_start_frame(out, avfilter_ref_pic(out->outpic, ~0));
     }