On Tue, 21 Jul 2020, lance.lmw...@gmail.com wrote:
On Tue, Jul 21, 2020 at 11:07:29AM +0200, Marton Balint wrote:On Tue, 21 Jul 2020, lance.lmw...@gmail.com wrote: > On Mon, Jul 20, 2020 at 11:04:38PM +0200, Marton Balint wrote: > > 50/60 fps timecode is using the field bit (which is the same as the phase > > correction bit) to signal the least significant bit of a 50/60 fps timecode. > > See SMPTE ST 12-1:2014 section 12.1.> > > > Let's add support for this by using the recently added av_timecode_get_smpte> > function which handles this properly.> > > > This change affects DV and MXF encoder, MXF has no fate for 50/60fps content,> > DV does, therefore the changes. It also affects decklink indev.> > > > MediaInfo (a recent version) confirms that half-frame timecode must be> > inserted. (although MediaInfo does not seem to check the field flag). > > MXFInspect confirms valid timecode insertion to the System Item of MXF files.> > > > Signed-off-by: Marton Balint <c...@passwd.hu>> > --- > > libavutil/timecode.c | 15 +-------------- > > libavutil/timecode.h | 7 +++---- > > tests/ref/vsynth/vsynth1-dv-hd | 2 +- > > tests/ref/vsynth/vsynth2-dv-hd | 2 +- > > tests/ref/vsynth/vsynth3-dv-hd | 2 +- > > tests/ref/vsynth/vsynth_lena-dv-hd | 2 +- > > 6 files changed, 8 insertions(+), 22 deletions(-)> > > > diff --git a/libavutil/timecode.c b/libavutil/timecode.c> > index cca53d73c4..cb916970ef 100644 > > --- a/libavutil/timecode.c > > +++ b/libavutil/timecode.c > > @@ -65,20 +65,7 @@ uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum) > > ss = framenum / fps % 60; > > mm = framenum / (fps*60) % 60; > > hh = framenum / (fps*3600) % 24; > > - return 0 << 31 | // color frame flag (0: unsync mode, 1: sync mode) > > - drop << 30 | // drop frame flag (0: non drop, 1: drop) > > - (ff / 10) << 28 | // tens of frames > > - (ff % 10) << 24 | // units of frames > > - 0 << 23 | // PC (NTSC) or BGF0 (PAL) > > - (ss / 10) << 20 | // tens of seconds > > - (ss % 10) << 16 | // units of seconds > > - 0 << 15 | // BGF0 (NTSC) or BGF2 (PAL) > > - (mm / 10) << 12 | // tens of minutes > > - (mm % 10) << 8 | // units of minutes > > - 0 << 7 | // BGF2 (NTSC) or PC (PAL) > > - 0 << 6 | // BGF1 > > - (hh / 10) << 4 | // tens of hours > > - (hh % 10); // units of hours > > + return av_timecode_get_smpte(tc->rate, drop, hh, mm, ss, ff);> > av_timecode_get_smpte() is used by the h264/hevc, and the specs reserved more bits for ff, so in case it's> > 30fps, so av_timecode_get_smpte() will divide ff by 2 to get frame pair. But for SMPTE ST 12 specs, the > ff reserved 2 bits for tens, so for > 30fps, it's supported by frame pair and ff > is divide by 2 already by the spec, so you'll get unexpected results if divide > by 2 again(four frame pair if test) I don't understand what you want to say. av_timecode_get_smpte_from_framenum is a function for which the number of frames (as a single integer) is passed. Clearly the number of frames as a single integer is not divided by anything, so there cannot be double division when av_timecode_get_smpte_from_framenum() calls av_timecode_get_smpte().For example, when I'm print out the tc from timecode->GetString(&decklink_tc) in decklink_dec.cpp for fps = 50, the tc will be: 00:00:00:00 00:00:00:00 -> repeat TC for frame pair 00:00:00:01 00:00:00:01 -> repeat .... 00:00:00:24 00:00:00:24 -> repeat, 50 frame now 00:00:00:00 00:00:00:00 -> repeat
That's because your input is containing the wrong timecode, as I suggested in the other thread.
If the av_timecode_get_smpte_from_framenum(), the ff will be divided by 2 after change, you'll get below: 00:00:00:00 00:00:00:00 00:00:00:00 00:00:00:00 00:00:00:01 00:00:00:01 00:00:00:01 00:00:00:01 .... 00:00:00:12 00:00:00:12 00:00:00:12 00:00:00:12 -> 50 frame now, repeat 4 times 00:00:00:00 00:00:00:00 00:00:00:00 00:00:00:00
And this is because av_timecode_make_smpte_tc_string does not handle 50fps timecodes properly.
Regards, Marton
I'm not sure whether it's clear to explain my meaning.Regards, Marton> > > > } > > > > uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff)> > diff --git a/libavutil/timecode.h b/libavutil/timecode.h > > index 5801330921..e54b116e93 100644 > > --- a/libavutil/timecode.h > > +++ b/libavutil/timecode.h > > @@ -66,11 +66,11 @@ int av_timecode_adjust_ntsc_framenum2(int framenum, int fps); > > * the format description as follows: > > * bits 0-5: hours, in BCD(6bits) > > * bits 6: BGF1 > > - * bits 7: BGF2 (NTSC) or PC (PAL) > > + * bits 7: BGF2 (NTSC) or FIELD (PAL) > > * bits 8-14: minutes, in BCD(7bits) > > * bits 15: BGF0 (NTSC) or BGF2 (PAL) > > * bits 16-22: seconds, in BCD(7bits) > > - * bits 23: PC (NTSC) or BGF0 (PAL) > > + * bits 23: FIELD (NTSC) or BGF0 (PAL) > > * bits 24-29: frames, in BCD(6bits) > > * bits 30: drop frame flag (0: non drop, 1: drop) > > * bits 31: color frame flag (0: unsync mode, 1: sync mode) > > @@ -78,8 +78,7 @@ int av_timecode_adjust_ntsc_framenum2(int framenum, int fps); > > * @note Frame number adjustment is automatically done in case of drop timecode, > > * you do NOT have to call av_timecode_adjust_ntsc_framenum2(). > > * @note The frame number is relative to tc->start. > > - * @note Color frame (CF), binary group flags (BGF) and biphase mark polarity > > - * correction (PC) bits are set to zero. > > + * @note Color frame (CF) and binary group flags (BGF) bits are set to zero. > > */ > > uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum);> > > > diff --git a/tests/ref/vsynth/vsynth1-dv-hd b/tests/ref/vsynth/vsynth1-dv-hd> > index e22f28c704..a93ce50ec0 100644 > > --- a/tests/ref/vsynth/vsynth1-dv-hd > > +++ b/tests/ref/vsynth/vsynth1-dv-hd > > @@ -1,4 +1,4 @@ > > -77f146c73a24495495c649f1e0d26fee *tests/data/fate/vsynth1-dv-hd.dv > > +ce9f887af2391edbfcb21675962db54c *tests/data/fate/vsynth1-dv-hd.dv > > 14400000 tests/data/fate/vsynth1-dv-hd.dv > > 34b78cf725346c7f819c9d6209b8299a *tests/data/fate/vsynth1-dv-hd.out.rawvideo > > stddev: 4.30 PSNR: 35.45 MAXDIFF: 74 bytes: 7603200/ 7603200 > > diff --git a/tests/ref/vsynth/vsynth2-dv-hd b/tests/ref/vsynth/vsynth2-dv-hd > > index 5c4ed86fe7..9552c31948 100644 > > --- a/tests/ref/vsynth/vsynth2-dv-hd > > +++ b/tests/ref/vsynth/vsynth2-dv-hd > > @@ -1,4 +1,4 @@ > > -168f80951daf5eeefacac33fd06db87d *tests/data/fate/vsynth2-dv-hd.dv > > +c152c7c3f9ef8f404b4bb7a388b947be *tests/data/fate/vsynth2-dv-hd.dv > > 14400000 tests/data/fate/vsynth2-dv-hd.dv > > 15dbe911532aca81c67bdd2846419027 *tests/data/fate/vsynth2-dv-hd.out.rawvideo > > stddev: 1.75 PSNR: 43.26 MAXDIFF: 34 bytes: 7603200/ 7603200 > > diff --git a/tests/ref/vsynth/vsynth3-dv-hd b/tests/ref/vsynth/vsynth3-dv-hd > > index ed94d08155..d0420d6f07 100644 > > --- a/tests/ref/vsynth/vsynth3-dv-hd > > +++ b/tests/ref/vsynth/vsynth3-dv-hd > > @@ -1,4 +1,4 @@ > > -1211b843d8dde81c583023e15beff35a *tests/data/fate/vsynth3-dv-hd.dv > > +973b0856d1d94793bd6e8951284e642d *tests/data/fate/vsynth3-dv-hd.dv > > 14400000 tests/data/fate/vsynth3-dv-hd.dv > > a038ad7c3c09f776304ef7accdea9c74 *tests/data/fate/vsynth3-dv-hd.out.rawvideo > > stddev: 0.00 PSNR:999.99 MAXDIFF: 0 bytes: 86700/ 86700 > > diff --git a/tests/ref/vsynth/vsynth_lena-dv-hd b/tests/ref/vsynth/vsynth_lena-dv-hd > > index 6764f03c35..8b87da40ba 100644 > > --- a/tests/ref/vsynth/vsynth_lena-dv-hd > > +++ b/tests/ref/vsynth/vsynth_lena-dv-hd > > @@ -1,4 +1,4 @@ > > -fa8df53531f9e58f90bc9a33e5c78ca8 *tests/data/fate/vsynth_lena-dv-hd.dv > > +30652b3740a32fa8bcee3b06a66b1dd2 *tests/data/fate/vsynth_lena-dv-hd.dv > > 14400000 tests/data/fate/vsynth_lena-dv-hd.dv > > 4db4175c80ea1f16b7ec303611b8873a *tests/data/fate/vsynth_lena-dv-hd.out.rawvideo > > stddev: 1.49 PSNR: 44.66 MAXDIFF: 27 bytes: 7603200/ 7603200> > -- > > 2.26.2 > > > > _______________________________________________> > ffmpeg-devel mailing list > > ffmpeg-devel@ffmpeg.org > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel> > > > To unsubscribe, visit link above, or email> > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".> > -- > Thanks,> Limin Wang > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel> > To unsubscribe, visit link above, or email> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".-- Thanks, Limin Wang _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
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