}
SourceFrame const N = _film->dcp_trim_start() + _film->dcp_length().get();
- DCPFrameRate const dfr = dcp_frame_rate (_film->frames_per_second ());
+ DCPFrameRate const dfr (_film->frames_per_second ());
+
+ int const inc = dfr.skip ? 2 : 1;
- for (SourceFrame i = _film->dcp_trim_start(); i < N; i += dfr.skip) {
+ for (SourceFrame i = _film->dcp_trim_start(); i < N; i += inc) {
string const j2k_file = _encode_opt->frame_out_path (i, false);
string const hash_file = _encode_opt->hash_out_path (i, false);
* @param out Required size of output, in pixels (including any padding).
* @param s Scaler to use.
* @param p Number of pixels of padding either side of the image.
- * @param f Index of the frame within the Film.
- * @param fps Frames per second of the Film.
+ * @param f Index of the frame within the Film's source.
+ * @param fps Frames per second of the Film's source.
* @param pp FFmpeg post-processing string to use.
* @param clut Colour look-up table to use (see Config::colour_lut_index ())
* @param bw J2K bandwidth to use (see Config::j2k_bandwidth ())
, _subtitle_scale (subtitle_scale)
, _scaler (s)
, _frame (f)
- , _frames_per_second (dcp_frame_rate(fps).frames_per_second)
+ , _frames_per_second (DCPFrameRate(fps).frames_per_second)
, _post_process (pp)
, _colour_lut (clut)
, _j2k_bandwidth (bw)
void
Encoder::process_video (shared_ptr<Image> image, bool same, boost::shared_ptr<Subtitle> sub)
{
- if (_opt->video_skip != 0 && (_video_frame % _opt->video_skip) != 0) {
+ if (_opt->video_skip && (_video_frame % 2)) {
++_video_frame;
return;
}
if (dcp_length ()) {
oe->video_range = make_pair (dcp_trim_start(), dcp_trim_start() + dcp_length().get());
if (audio_stream()) {
+ DCPFrameRate dfr (frames_per_second ());
oe->audio_range = make_pair (
video_frames_to_audio_frames (
oe->video_range.get().first,
dcp_audio_sample_rate (audio_stream()->sample_rate()),
- dcp_frame_rate (frames_per_second()).frames_per_second
+ dfr.frames_per_second
),
video_frames_to_audio_frames (
oe->video_range.get().second,
dcp_audio_sample_rate (audio_stream()->sample_rate()),
- dcp_frame_rate (frames_per_second()).frames_per_second
+ dfr.frames_per_second
)
);
}
}
- oe->video_skip = dcp_frame_rate (frames_per_second()).skip;
+ oe->video_skip = DCPFrameRate (frames_per_second()).skip;
shared_ptr<DecodeOptions> od (new DecodeOptions);
od->decode_subtitles = with_subtitles ();
/* Resample to a DCI-approved sample rate */
double t = dcp_audio_sample_rate (audio_stream()->sample_rate());
- DCPFrameRate dfr = dcp_frame_rate (frames_per_second ());
+ DCPFrameRate dfr (frames_per_second ());
/* Compensate for the fact that video will be rounded to the
nearest integer number of frames per second.
*/
+
+ int const mult = dfr.skip ? 2 : 1;
if (dfr.run_fast) {
- t *= _frames_per_second * dfr.skip / dfr.frames_per_second;
+ t *= _frames_per_second * mult / dfr.frames_per_second;
}
return rint (t);
string
MakeDCPJob::j2c_path (int f, int offset) const
{
- SourceFrame const s = ((f + offset) * dcp_frame_rate(_film->frames_per_second()).skip) + _film->dcp_trim_start();
+ DCPFrameRate dfr (_film->frames_per_second());
+ int const mult = dfr.skip ? 2 : 1;
+ SourceFrame const s = ((f + offset) * mult) + _film->dcp_trim_start();
return _opt->frame_out_path (s, false);
}
/* Remove any old DCP */
boost::filesystem::remove_all (dcp_path);
- DCPFrameRate const dfr = dcp_frame_rate (_film->frames_per_second ());
+ DCPFrameRate const dfr (_film->frames_per_second ());
int frames = 0;
switch (_film->content_type ()) {
case VIDEO:
/* Source frames -> DCP frames */
- frames = _film->dcp_length().get() / dfr.skip;
+ frames = _film->dcp_length().get();
+ if (dfr.skip) {
+ frames /= 2;
+ }
break;
case STILL:
frames = _film->still_duration() * 24;
EncodeOptions (std::string f, std::string e, std::string m)
: padding (0)
- , video_skip (0)
+ , video_skip (false)
, _frame_out_path (f)
, _frame_out_extension (e)
, _multichannel_audio_out_path (m)
/** Range of audio frames to decode (in the DCP's sampling rate) */
boost::optional<std::pair<int64_t, int64_t> > audio_range;
- /** Skip frames such that we don't decode any frame where (index % decode_video_skip) != 0; e.g.
- * 1 for every frame, 2 for every other frame, etc.
- */
- SourceFrame video_skip;
+ /** true to skip every other frame */
+ SourceFrame video_skip;
private:
/** Path of the directory to write video frames to */
return s.str ();
}
-/** @param fps Arbitrary frames-per-second value.
- * @return DCPFrameRate for this frames-per-second.
- */
-DCPFrameRate
-dcp_frame_rate (float fps)
-{
- DCPFrameRate dfr;
-
- dfr.run_fast = (fps != rint (fps));
- dfr.frames_per_second = rint (fps);
- dfr.skip = 1;
-
- /* XXX: somewhat arbitrary */
- if (fps == 50) {
- dfr.frames_per_second = 25;
- dfr.skip = 2;
+static bool about_equal (float a, float b)
+{
+ /* A film of F seconds at f FPS will be Ff frames;
+ Consider some delta FPS d, so if we run the same
+ film at (f + d) FPS it will last F(f + d) seconds.
+
+ Hence the difference in length over the length of the film will
+ be F(f + d) - Ff frames
+ = Ff + Fd - Ff frames
+ = Fd frames
+ = Fd/f seconds
+
+ So if we accept a difference of 1 frame, ie 1/f seconds, we can
+ say that
+
+ 1/f = Fd/f
+ ie 1 = Fd
+ ie d = 1/F
+
+ So for a 3hr film, ie F = 3 * 60 * 60 = 10800, the acceptable
+ FPS error is 1/F ~= 0.0001 ~= 10-e4
+ */
+
+ return (fabs (a - b) < 1e-4);
+}
+
+/** @param fps Arbitrary source frames-per-second value */
+DCPFrameRate::DCPFrameRate (float fps)
+ : frames_per_second (rint (fps))
+ , skip (false)
+ , repeat (false)
+ , run_fast (false)
+{
+ if (about_equal (fps, 50)) {
+ /* XXX: not sure about this; just run at 50?
+ Ring Peter Jackson.
+ */
+ frames_per_second = 25;
+ skip = true;
+ } else if (fps >= (27.5 / 2) && fps <= (32.5 / 2)) {
+ frames_per_second = 30;
+ repeat = true;
+ } else if (fps >= (24.5 / 2) && fps <= (27.5 / 2)) {
+ frames_per_second = 25;
+ repeat = true;
+ } else if (fps >= (20 / 2) && fps <= (24.5 / 2)) {
+ frames_per_second = 24;
+ repeat = true;
}
-
- return dfr;
}
/** @param An arbitrary sampling rate.
struct DCPFrameRate
{
+ DCPFrameRate (float);
+
/** frames per second for the DCP */
int frames_per_second;
- /** Skip every `skip' frames. e.g. if this is 1, we skip nothing;
- * if it's 2, we skip every other frame.
- */
- int skip;
+ /** true to skip every other frame */
+ bool skip;
+ /** true to repeat every frame once */
+ bool repeat;
/** true if this DCP will run its video faster than the source
- * (e.g. if the source is 29.97fps and we will run the DCP at 30fps)
+ * without taking into account `skip' and `repeat'.
+ * (i.e. run_fast will be true if
+ * source is 29.97fps, DCP is 30fps
+ * source is 14.50fps, DCP is 30fps
+ * but not if
+ * source is 15.00fps, DCP is 30fps
+ * source is 12.50fps, DCP is 25fps)
*/
bool run_fast;
};
extern std::string crop_string (Position, Size);
extern int dcp_audio_sample_rate (int);
-extern DCPFrameRate dcp_frame_rate (float);
extern int dcp_audio_channels (int);
extern std::string colour_lut_index_to_name (int index);
extern int stride_round_up (int, int const *, int);
projects / dcpomatic.git / commitdiff