[FFmpeg-devel] [PATCH 1/4] avutil: support 50 and 60 frame rates in timecode api
Michael Niedermayer
michaelni at gmx.at
Fri Jul 27 13:48:08 CEST 2012
On Wed, Jul 25, 2012 at 01:53:46AM +0200, Michael Niedermayer wrote:
> On Wed, May 30, 2012 at 08:27:19PM +0200, Matthieu Bouron wrote:
> > On Sun, May 27, 2012 at 2:21 PM, Matthieu Bouron
> > <matthieu.bouron at gmail.com> wrote:
> > > ---
> > > Hi there,
> > >
> > > This patch introduce support for 50/60 frame rates and a new function
> > > av_timecode_adjust_ntsc_framenum2 to handle both 29.97 and 59.94 cases.
> > >
> > > Note: the original formula comes from:
> > > http://www.andrewduncan.ws/Timecodes/Timecodes.html
> > >
> > > Regards,
> > > Matthieu
> > > ---
> > > libavcodec/mpeg12enc.c | 2 +-
> > > libavutil/avutil.h | 3 +++
> > > libavutil/timecode.c | 28 +++++++++++++++++++++++++---
> > > libavutil/timecode.h | 13 ++++++++++++-
> > > 4 files changed, 41 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c
> > > index 169f155..b045c74 100644
> > > --- a/libavcodec/mpeg12enc.c
> > > +++ b/libavcodec/mpeg12enc.c
> > > @@ -300,7 +300,7 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
> > > s->gop_picture_number = s->current_picture_ptr->f.coded_picture_number;
> > > av_assert0(s->drop_frame_timecode == !!(s->tc.flags & AV_TIMECODE_FLAG_DROPFRAME));
> > > if (s->drop_frame_timecode)
> > > - time_code = av_timecode_adjust_ntsc_framenum(time_code);
> > > + time_code = av_timecode_adjust_ntsc_framenum2(time_code, fps);
> > > put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
> > > put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
> > > put_bits(&s->pb, 1, 1);
> > > diff --git a/libavutil/avutil.h b/libavutil/avutil.h
> > > index acef213..c1c228c 100644
> > > --- a/libavutil/avutil.h
> > > +++ b/libavutil/avutil.h
> > > @@ -193,6 +193,9 @@
> > > #ifndef FF_API_OLD_AVOPTIONS
> > > #define FF_API_OLD_AVOPTIONS (LIBAVUTIL_VERSION_MAJOR < 52)
> > > #endif
> > > +#ifndef FF_API_OLD_TC_ADJUST_FRAMENUM
> > > +#define FF_API_OLD_TC_ADJUST_FRAMENUM (LIBAVUTIL_VERSION_MAJOR < 52)
> > > +#endif
> > >
> > > /**
> > > * @}
> > > diff --git a/libavutil/timecode.c b/libavutil/timecode.c
> > > index ad3f7fa..dcb93cb 100644
> > > --- a/libavutil/timecode.c
> > > +++ b/libavutil/timecode.c
> > > @@ -31,6 +31,7 @@
> > > #include "log.h"
> > > #include "error.h"
> > >
> > > +#ifdef FF_API_OLD_TC_ADJUST_FRAMENUM
> > > int av_timecode_adjust_ntsc_framenum(int framenum)
> > > {
> > > /* only works for NTSC 29.97 */
> > > @@ -39,6 +40,25 @@ int av_timecode_adjust_ntsc_framenum(int framenum)
> > > //if (m < 2) m += 2; /* not needed since -2,-1 / 1798 in C returns 0 */
> > > return framenum + 18 * d + 2 * ((m - 2) / 1798);
> > > }
> > > +#endif
> > > +
> > > +int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
> > > +{
> > > + /* only works for NTSC 29.97 and 59.94 */
> > > + int drop_frames = 0;
> > > + int d = framenum / 17982;
> > > + int m = framenum % 17982;
> > > +
> > > + if (fps == 30)
> > > + drop_frames = 2;
> > > + else if (fps == 60)
> > > + drop_frames = 4;
> > > + else
> > > + return framenum;
> > > +
> > > + //if (m < 2) m += 2; /* not needed since -2,-1 / 1798 in C returns 0 */
> > > + return framenum + 9 * drop_frames * d + drop_frames * ((m - 2) / 1798);
> > > +}
> > >
> > > uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
> > > {
> > > @@ -48,7 +68,7 @@ uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
> > >
> > > framenum += tc->start;
> > > if (drop)
> > > - framenum = av_timecode_adjust_ntsc_framenum(framenum);
> > > + framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps);
> > > ff = framenum % fps;
> > > ss = framenum / fps % 60;
> > > mm = framenum / (fps*60) % 60;
> > > @@ -77,7 +97,7 @@ char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
> > >
> > > framenum += tc->start;
> > > if (drop)
> > > - framenum = av_timecode_adjust_ntsc_framenum(framenum);
> > > + framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps);
> > > if (framenum < 0) {
> > > framenum = -framenum;
> > > neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE;
> > > @@ -139,7 +159,9 @@ static int check_timecode(void *log_ctx, AVTimecode *tc)
> > > switch (tc->fps) {
> > > case 24:
> > > case 25:
> > > - case 30: return 0;
> > > + case 30:
> > > + case 50:
> > > + case 60: return 0;
> > >
> > > default:
> > > av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate not supported\n");
> > > diff --git a/libavutil/timecode.h b/libavutil/timecode.h
> > > index 41e56d6..525f2a9 100644
> > > --- a/libavutil/timecode.h
> > > +++ b/libavutil/timecode.h
> > > @@ -57,8 +57,19 @@ typedef struct {
> > > * @param framenum frame number to adjust
> > > * @return adjusted frame number
> > > * @warning adjustment is only valid in NTSC 29.97
> > > + * @deprecated use av_timecode_adjust_ntsc_framenum2 instead
> > > */
> > > -int av_timecode_adjust_ntsc_framenum(int framenum);
> > > +attribute_deprecated int av_timecode_adjust_ntsc_framenum(int framenum);
> > > +
> > > +/**
> > > + * Adjust frame number for NTSC drop frame time code.
> > > + *
> > > + * @param framenum frame number to adjust
> > > + * @param fps frame per second, 30 or 60
> > > + * @return adjusted frame number
> > > + * @warning adjustment is only valid in NTSC 29.97 and 59.94
> > > + */
> > > +int av_timecode_adjust_ntsc_framenum2(int framenum, int fps);
> > >
> > > /**
> > > * Convert frame number to SMPTE 12M binary representation.
> > > --
> > > 1.7.10
> > >
> >
> > ping
>
> i will apply this in the next few days if there are no comments/review
> from anyone else
applied
thanks
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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