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LTC Slave: improve fps detection

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and fix a few minor typos in the related doc

git-svn-id: svn://localhost/ardour2/branches/3.0@13338 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Robin Gareus 2012-10-25 17:07:59 +00:00
parent acb795980b
commit 8cff3d0e60
2 changed files with 56 additions and 5 deletions
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3
libs/ardour/ardour/slave.h
View File

@ -352,6 +352,7 @@ public:
void parse_ltc(const jack_nframes_t, const jack_default_audio_sample_t * const, const framecnt_t);
void process_ltc(framepos_t const);
void init_engine_dll (framepos_t, int32_t);
bool detect_discontinuity(LTCFrameExt *, int, bool);
bool detect_ltc_fps(int, bool);
void reset();
@ -362,6 +363,8 @@ public:
LTCDecoder * decoder;
double frames_per_ltc_frame;
Timecode::Time timecode;
LTCFrameExt prev_frame;
bool fps_detected;
framecnt_t monotonic_cnt;
framecnt_t last_timestamp;

56
libs/ardour/ltc_slave.cc
View File

@ -52,10 +52,11 @@ LTC_Slave::LTC_Slave (Session& s)
delayedlocked = 10;
monotonic_cnt = 0;
ltc_timecode = timecode_60; // track changes of LTC timecode
a3e_timecode = timecode_60; // track canges of Ardour's timecode
ltc_timecode = timecode_60; // track changes of LTC fps
a3e_timecode = timecode_60; // track changes of Ardour's fps
printed_timecode_warning = false;
ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
memset(&prev_frame, 0, sizeof(LTCFrameExt));
decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
reset();
@ -97,6 +98,7 @@ LTC_Slave::reset()
transport_direction = 0;
ltc_speed = 0;
engine_dll_initstate = 0;
fps_detected=false;
}
void
@ -106,7 +108,7 @@ LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_samp
unsigned char sound[8192];
if (nframes > 8192) {
/* TODO warn once or wrap, loop conversion below
* does A3 support > 8192 spp anyway?
* does jack/A3 support > 8192 spp anyway?
*/
return;
}
@ -119,6 +121,45 @@ LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_samp
return;
}
bool
LTC_Slave::detect_discontinuity(LTCFrameExt *frame, int fps, bool fuzzy) {
bool discontinuity_detected = false;
if (fuzzy && (
(frame->reverse && prev_frame.ltc.frame_units == 0)
||(!frame->reverse && frame->ltc.frame_units == 0)
))
{
memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
return false;
}
if (frame->reverse) {
ltc_frame_decrement(&prev_frame.ltc, fps , 0);
} else {
ltc_frame_increment(&prev_frame.ltc, fps , 0);
}
LTCFrame *a = &prev_frame.ltc;
LTCFrame *b = &frame->ltc;
if ( a->frame_units != b->frame_units
|| a->frame_tens != b->frame_tens
|| a->dfbit != b->dfbit
|| a->secs_units != b->secs_units
|| a->secs_tens != b->secs_tens
|| a->mins_units != b->mins_units
|| a->mins_tens != b->mins_tens
|| a->hours_units != b->hours_units
|| a->hours_tens != b->hours_tens
)
{
discontinuity_detected = true;
}
memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
return discontinuity_detected;
}
bool
LTC_Slave::detect_ltc_fps(int frameno, bool df)
{
@ -170,7 +211,7 @@ LTC_Slave::detect_ltc_fps(int frameno, bool df)
did_reset_tc_format = true;
}
if (cur_timecode != tc_format) {
warning << string_compose(_("Session framerate adjusted from %1 TO: LTC's %2."),
warning << string_compose(_("Session framerate adjusted from %1 to LTC's %2."),
Timecode::timecode_format_name(cur_timecode),
Timecode::timecode_format_name(tc_format))
<< endmsg;
@ -207,9 +248,16 @@ LTC_Slave::process_ltc(framepos_t const now)
timecode.subframes = 0;
/* set timecode.rate and timecode.drop: */
if (detect_discontinuity(&frame, ceil(timecode.rate), !fps_detected)) {
ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
fps_detected=false;
}
if (detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
reset();
last_timestamp = 0;
fps_detected=true;
}
#if 0 // Devel/Debug