diff options
| author | Carl Hetherington <cth@carlh.net> | 2020-08-02 22:24:05 +0200 |
|---|---|---|
| committer | Carl Hetherington <cth@carlh.net> | 2020-08-02 22:24:05 +0200 |
| commit | af680761cf7c3e97660e8e55c68f42e90b026bf9 (patch) | |
| tree | 3245845f36c214023e936fce104c49b91168685c /src/lib/ffmpeg_content.cc | |
| parent | a0545f58b3e90d3c09fa376900eafd6f8fb531cb (diff) | |
Detect soft 2:3 pulldown (telecine) files and decode them at 23.976.
DVD rips from NTSC DVDs are sometimes (always?) encoded using
soft 2:3 pulldown. The video frames are actually 23.976 but
FFmpeg detects them as 29.97. With the current approach of the video
decoder ignoring most PTSs and assuming a constant frame rate
it is vital that the file contains the number of frames per second
that the detected frame rate predicts.
This fixes large sync errors with NTSC DVD rips (#1790).
Diffstat (limited to 'src/lib/ffmpeg_content.cc')
| -rw-r--r-- | src/lib/ffmpeg_content.cc | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/lib/ffmpeg_content.cc b/src/lib/ffmpeg_content.cc index f3c0d01cb..1fb95535f 100644 --- a/src/lib/ffmpeg_content.cc +++ b/src/lib/ffmpeg_content.cc @@ -337,6 +337,14 @@ FFmpegContent::examine (shared_ptr<const Film> film, shared_ptr<Job> job) set_default_colour_conversion (); } + if (examiner->has_video() && examiner->pulldown() && video_frame_rate() && fabs(*video_frame_rate() - 29.97) < 0.001) { + /* FFmpeg has detected this file as 29.97 and the examiner thinks it is using "soft" 2:3 pulldown (telecine). + * This means we can treat it as a 23.976fps file. + */ + set_video_frame_rate (24000.0 / 1001); + video->set_length (video->length() * 24.0 / 30); + } + #ifdef DCPOMATIC_VARIANT_SWAROOP _id = examiner->id (); #endif |