ffmpeg: fix aspect ratio setting

This is done by adding a setsar filter at the beginning of the
configured filterchain.

This implementation is more robust, since does not modify the
filterchain description (which was creating potential syntax errors),
but directly modifies the filterchain structure.

This also changes the ffmpeg -aspect behavior, as following filters in
the filterchain can change the DAR/SAR set by the inserted setsar
filter.

Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>

1 files changed, 10 insertions, 12 deletions

diff --git a/ffmpeg.c b/ffmpeg.c
index dc8e1b7512..cb23581ca4 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -149,7 +149,6 @@ static int nb_streamid_map = 0;
 static int frame_width  = 0;
 static int frame_height = 0;
 static float frame_aspect_ratio = 0;
-static int frame_aspect_ratio_override = 0;
 static enum PixelFormat frame_pix_fmt = PIX_FMT_NONE;
 static int frame_bits_per_raw_sample = 0;
 static enum AVSampleFormat audio_sample_fmt = AV_SAMPLE_FMT_NONE;
@@ -397,6 +396,16 @@ static int configure_filters(AVInputStream *ist, AVOutputStream *ost)
             return ret;
         last_filter = filter;
     }
+    if (av_cmp_q(codec->sample_aspect_ratio, icodec->sample_aspect_ratio)) {
+        snprintf(args, 255, "%d:%d",
+                 codec->sample_aspect_ratio.num, codec->sample_aspect_ratio.den);
+        if ((ret = avfilter_graph_create_filter(&filter, avfilter_get_by_name("setsar"),
+                                                NULL, args, NULL, ost->graph)) < 0)
+            return ret;
+        if ((ret = avfilter_link(last_filter, 0, filter, 0)) < 0)
+            return ret;
+        last_filter = filter;
+    }
 
     snprintf(args, sizeof(args), "flags=0x%X", (int)av_get_int(sws_opts, "sws_flags", NULL));
     ost->graph->scale_sws_opts = av_strdup(args);
@@ -2894,7 +2903,6 @@ static void opt_frame_aspect_ratio(const char *arg)
         ffmpeg_exit(1);
     }
     frame_aspect_ratio = ar;
-    frame_aspect_ratio_override = 1;
 }
 
 static int opt_metadata(const char *opt, const char *arg)
@@ -3335,7 +3343,6 @@ static void opt_input_file(const char *filename)
             else
                 frame_aspect_ratio=av_q2d(dec->sample_aspect_ratio);
             frame_aspect_ratio *= (float) dec->width / dec->height;
-            frame_aspect_ratio_override = 0;
             frame_pix_fmt = dec->pix_fmt;
             rfps      = ic->streams[i]->r_frame_rate.num;
             rfps_base = ic->streams[i]->r_frame_rate.den;
@@ -3440,7 +3447,6 @@ static void new_video_stream(AVFormatContext *oc, int file_idx)
     AVCodecContext *video_enc;
     enum CodecID codec_id = CODEC_ID_NONE;
     AVCodec *codec= NULL;
-    int i;
 
     st = av_new_stream(oc, oc->nb_streams < nb_streamid_map ? streamid_map[oc->nb_streams] : 0);
     if (!st) {
@@ -3461,14 +3467,6 @@ static void new_video_stream(AVFormatContext *oc, int file_idx)
             codec = avcodec_find_encoder(codec_id);
         }
 #if CONFIG_AVFILTER
-        if(frame_aspect_ratio_override){
-            i = vfilters ? strlen(vfilters) : 0;
-            vfilters = av_realloc(vfilters, i+100);
-            snprintf(vfilters+i, 100, "%csetdar=%f\n", i?',':' ', frame_aspect_ratio);
-            frame_aspect_ratio=0;
-            frame_aspect_ratio_override=0;
-        }
-
         ost->avfilter= vfilters;
         vfilters= NULL;
 #endif