Closes #164: Allow jumping back in time to lower HLS segments

src/ffmpeg_transcoder.cc

@@ -5535,7 +5535,8 @@ int FFmpeg_Transcoder::start_new_segment()
         // No check if m_segment_duration == 0, values <= 0 not accepted
         // Cast is OK here, the result will always be small enough for an int32.
         uint32_t min_seek_segments = static_cast<uint32_t>(params.m_min_seek_time_diff / params.m_segment_duration);
-        if (min_seek_segments && next_segment + min_seek_segments >= segment_no)
+
+        if (min_seek_segments && segment_no >= next_segment && segment_no <= next_segment + min_seek_segments)
         {
             Logging::info(virtname(), "Discarding seek request to HLS segment no. %1, less than %2 seconds (%3 segments) away.", segment_no, params.m_min_seek_time_diff / AV_TIME_BASE, min_seek_segments);
             continue;