[FFmpeg-devel] [PATCH 03/12] Retreive width and height from video stream!

[Traian Coza]

---
 fftools/ffmpeg.c           | 29 ++++++++++++++++++++++++++---
 libavfilter/vf_subtitles.c |  9 ++++-----
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index dea2aec2ce..a74800bb68 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -2325,7 +2325,7 @@ fail:
     return err < 0 ? err : ret;
 }
 
-void render_avsub_ass(InputStream *, AVSubtitle *);
+void render_avsub_ass(InputStream *, AVSubtitle *, int, int);
 
 static void print_subtitle(AVSubtitle sub)
 {
@@ -2423,7 +2423,7 @@ static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output,
 
     ist->frames_decoded++;
 
-    int rendered = 0;
+    int rendered = 0;       // Variable for text to bitmap support
     for (i = 0; i < nb_output_streams; i++) {
         OutputStream *ost = output_streams[i];
 
@@ -2431,10 +2431,33 @@ static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output,
             || ost->enc->type != AVMEDIA_TYPE_SUBTITLE)
             continue;
 
+        // Support text to bitmap
         if (avcodec_descriptor_get(ost->enc_ctx->codec_id)->props & AV_CODEC_PROP_BITMAP_SUB)
             if (avcodec_descriptor_get(ist->dec_ctx->codec_id)->props & AV_CODEC_PROP_TEXT_SUB)
                 if (!rendered) {
-                    render_avsub_ass(ist, &subtitle);
+                    // Try to get a height and width from a video
+                    int width = 0, height = 0;
+                    // Try output streams
+                    for (int j = 0; j < nb_output_streams; j++)
+                        if (output_streams[j]->enc_ctx->codec_type == AVMEDIA_TYPE_VIDEO)
+                        {
+                            width = output_streams[j]->enc_ctx->width;
+                            height = output_streams[j]->enc_ctx->height;
+                            break;
+                        }
+                    if (width == 0)
+                        // Try input streams
+                        for (int j = 0; j < nb_input_streams; j++)
+                            if (input_streams[j]->dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO)
+                            {
+                                width = input_streams[j]->dec_ctx->width;
+                                height = input_streams[j]->dec_ctx->height;
+                                break;
+                            }
+                    if (width == 0) {
+                        // TODO Error: Cannot render without a video stream
+                    }
+                    render_avsub_ass(ist, &subtitle, width, height);
                     for (int r = 0; r < subtitle.num_rects; r++)
                         subtitle.rects[r]->type = SUBTITLE_BITMAP;
                     rendered = 1;
diff --git a/libavfilter/vf_subtitles.c b/libavfilter/vf_subtitles.c
index 16f9c3fff6..7226911f6c 100644
--- a/libavfilter/vf_subtitles.c
+++ b/libavfilter/vf_subtitles.c
@@ -223,16 +223,15 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
 
 #define ALPHA_THRESHOLD 0b10000000
 
-void render_avsub_ass(InputStream *, AVSubtitle *);
-void render_avsub_ass(InputStream *ist, AVSubtitle *sub)
+void render_avsub_ass(InputStream *, AVSubtitle *, int, int);
+void render_avsub_ass(InputStream *ist, AVSubtitle *sub, int frame_width, int frame_height)
 {
     ASS_Library *library = ass_library_init();
     ass_set_extract_fonts(library, 1);
     ASS_Renderer *renderer = ass_renderer_init(library);
-    int w = 1920, h = 1080;
-    ass_set_frame_size(renderer, w, h);
+    ass_set_frame_size(renderer, frame_width, frame_height);
     ass_set_pixel_aspect(renderer, 1);
-    ass_set_storage_size(renderer, w, h);
+    ass_set_storage_size(renderer, frame_width, frame_height);
     ass_set_shaper(renderer, 0);
     ass_set_fonts(renderer, NULL, NULL, 1, NULL, 1);
 
-- 
2.34.1