Fix lack of video rotation in some cases (#2971).

[dcpomatic.git] / src / lib / ffmpeg_examiner.cc

diff --git a/src/lib/ffmpeg_examiner.cc b/src/lib/ffmpeg_examiner.cc
index 46f4f236e889515eca0254da7f7195be74efb5bb..787198e4a477417570880bfdfe11bc8322ccf017 100644 (file)
--- a/src/lib/ffmpeg_examiner.cc
+++ b/src/lib/ffmpeg_examiner.cc
@@ -182,7 +182,6 @@ FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c, shared_ptr<Jo
                auto stream = _format_context->streams[*_video_stream];
                auto rotate_tag = av_dict_get (stream->metadata, "rotate", 0, 0);
                uint8_t* displaymatrix = av_stream_get_side_data (stream, AV_PKT_DATA_DISPLAYMATRIX, 0);
-               _rotation = 0;
 
                if (rotate_tag && *rotate_tag->value && strcmp(rotate_tag->value, "0")) {
                        char *tail;
@@ -305,7 +304,7 @@ FFmpegExaminer::video_frame_rate () const
 }
 
 
-dcp::Size
+optional<dcp::Size>
 FFmpegExaminer::video_size () const
 {
        return dcp::Size (video_codec_context()->width, video_codec_context()->height);
@@ -383,6 +382,19 @@ FFmpegExaminer::bits_per_pixel () const
 }
 
 
+bool
+FFmpegExaminer::has_alpha() const
+{
+       if (video_codec_context()->pix_fmt == -1) {
+               return false;
+       }
+
+       auto const d = av_pix_fmt_desc_get(video_codec_context()->pix_fmt);
+       DCPOMATIC_ASSERT(d);
+       return d->flags & AV_PIX_FMT_FLAG_ALPHA;
+}
+
+
 bool
 FFmpegExaminer::yuv () const
 {