- int64_t const t = static_cast<int64_t>(f) / (av_q2d (_format_context->streams[_video_stream]->time_base) * frames_per_second());
- int const r = av_seek_frame (_format_context, _video_stream, t, 0);
+ /* This AVSEEK_FLAG_BACKWARD in do_seek is a bit of a hack; without it, if we ask for a seek to the same place as last time
+ (used when we change decoder parameters and want to re-fetch the frame) we end up going forwards rather than
+ staying in the same place.
+ */
+ return do_seek (last_source_time(), true);
+}
+
+bool
+FFmpegDecoder::do_seek (double p, bool backwards)
+{
+ int64_t const vt = p / av_q2d (_format_context->streams[_video_stream]->time_base);
+
+ int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
+