vsrc_buffer: add sample_aspect_ratio fields to arguments.

This fixes aspect handling in ffmpeg.

This is based on a patch by Baptiste.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:   2011-04-18
 
 API changes, most recent first:
 
+2011-04-xx - xxxxxx - lavfi 2.2.0 - vsrc_buffer
+  Add sample_aspect_ratio fields to vsrc_buffer arguments
+
 2011-04-21 - 94f7451 - lavc 53.1.0 - avcodec.h
   Add CODEC_CAP_SLICE_THREADS for codecs supporting sliced threading.
 

doc/filters.texi

@@ -1190,7 +1190,7 @@ This source is mainly intended for a programmatic use, in particular
 through the interface defined in @file{libavfilter/vsrc_buffer.h}.
 
 It accepts the following parameters:
-@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}
+@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}
 
 All the parameters need to be explicitely defined.
 
@@ -1209,15 +1209,20 @@ name.
 @item timebase_num, timebase_den
 Specify numerator and denomitor of the timebase assumed by the
 timestamps of the buffered frames.
+
+@item sample_aspect_ratio.num, sample_aspect_ratio.den
+Specify numerator and denominator of the sample aspect ratio assumed
+by the video frames.
 @end table
 
 For example:
 @example
-buffer=320:240:yuv410p:1:24
+buffer=320:240:yuv410p:1:24:1:1
 @end example
 
 will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p" and assuming 1/24 as the timestamps timebase.
+with format "yuv410p", assuming 1/24 as the timestamps timebase and
+square pixels (1:1 sample aspect ratio).
 Since the pixel format with name "yuv410p" corresponds to the number 6
 (check the enum PixelFormat definition in @file{libavutil/pixfmt.h}),
 this example corresponds to:

ffmpeg.c

@@ -344,13 +344,21 @@ static int configure_filters(AVInputStream *ist, AVOutputStream *ost)
     AVCodecContext *codec = ost->st->codec;
     AVCodecContext *icodec = ist->st->codec;
     FFSinkContext ffsink_ctx = { .pix_fmt = codec->pix_fmt };
+    AVRational sample_aspect_ratio;
     char args[255];
     int ret;
 
     graph = avfilter_graph_alloc();
 
-    snprintf(args, 255, "%d:%d:%d:%d:%d", ist->st->codec->width,
-             ist->st->codec->height, ist->st->codec->pix_fmt, 1, AV_TIME_BASE);
+    if (ist->st->sample_aspect_ratio.num){
+        sample_aspect_ratio = ist->st->sample_aspect_ratio;
+    }else
+        sample_aspect_ratio = ist->st->codec->sample_aspect_ratio;
+
+    snprintf(args, 255, "%d:%d:%d:%d:%d:%d:%d", ist->st->codec->width,
+             ist->st->codec->height, ist->st->codec->pix_fmt, 1, AV_TIME_BASE,
+             sample_aspect_ratio.num, sample_aspect_ratio.den);
+
     ret = avfilter_graph_create_filter(&ist->input_video_filter, avfilter_get_by_name("buffer"),
                                        "src", args, NULL, graph);
     if (ret < 0)
@@ -404,6 +412,8 @@ static int configure_filters(AVInputStream *ist, AVOutputStream *ost)
 
     codec->width  = ist->output_video_filter->inputs[0]->w;
     codec->height = ist->output_video_filter->inputs[0]->h;
+    codec->sample_aspect_ratio = ost->st->sample_aspect_ratio =
+        ist->output_video_filter->inputs[0]->sample_aspect_ratio;
 
     return 0;
 }
@@ -2784,6 +2794,10 @@ static void opt_frame_aspect_ratio(const char *arg)
         ffmpeg_exit(1);
     }
     frame_aspect_ratio = ar;
+
+    x = vfilters ? strlen(vfilters) : 0;
+    vfilters = av_realloc(vfilters, x+100);
+    snprintf(vfilters+x, x+100, "%csetdar=%f\n", x?',':' ', ar);
 }
 
 static int opt_metadata(const char *opt, const char *arg)

libavfilter/avfilter.h

@@ -26,7 +26,7 @@
 #include "libavutil/samplefmt.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  2
-#define LIBAVFILTER_VERSION_MINOR  1
+#define LIBAVFILTER_VERSION_MINOR  2
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vsrc_buffer.c

@@ -68,8 +68,10 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
     int n = 0;
 
     if (!args ||
-        (n = sscanf(args, "%d:%d:%127[^:]:%d:%d", &c->w, &c->h, pix_fmt_str, &c->time_base.num, &c->time_base.den)) != 5) {
-        av_log(ctx, AV_LOG_ERROR, "Expected 5 arguments, but only %d found in '%s'\n", n, args);
+        (n = sscanf(args, "%d:%d:%127[^:]:%d:%d:%d:%d", &c->w, &c->h, pix_fmt_str,
+                    &c->time_base.num, &c->time_base.den,
+                    &c->pixel_aspect.num, &c->pixel_aspect.den)) != 7) {
+        av_log(ctx, AV_LOG_ERROR, "Expected 7 arguments, but only %d found in '%s'\n", n, args);
         return AVERROR(EINVAL);
     }
     if ((c->pix_fmt = av_get_pix_fmt(pix_fmt_str)) == PIX_FMT_NONE) {
@@ -100,6 +102,7 @@ static int config_props(AVFilterLink *link)
 
     link->w = c->w;
     link->h = c->h;
+    link->sample_aspect_ratio = c->pixel_aspect;
     link->time_base = c->time_base;
 
     return 0;