[FFmpeg-devel] [PATCH v3 1/2] API: add AV_PKT_DATA_S12M_TIMECODE to AVPacketSideDataType
lance.lmwang at gmail.com
lance.lmwang at gmail.com
Tue Jun 30 04:30:29 EEST 2020
On Tue, Jun 30, 2020 at 01:54:06AM +0200, Andreas Rheinhardt wrote:
> lance.lmwang at gmail.com:
> > On Mon, Jun 29, 2020 at 06:18:23PM +0200, Andreas Rheinhardt wrote:
> >> lance.lmwang at gmail.com:
> >>> On Mon, Jun 29, 2020 at 05:35:58PM +0200, Andreas Rheinhardt wrote:
> >>>> lance.lmwang at gmail.com:
> >>>>> From: Limin Wang <lance.lmwang at gmail.com>
> >>>>>
> >>>>> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> >>>>> ---
> >>>>> doc/APIchanges | 3 +++
> >>>>> libavcodec/avpacket.c | 1 +
> >>>>> libavcodec/decode.c | 1 +
> >>>>> libavcodec/packet.h | 6 ++++++
> >>>>> libavcodec/version.h | 2 +-
> >>>>> libavformat/dump.c | 21 +++++++++++++++++++++
> >>>>> 6 files changed, 33 insertions(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/doc/APIchanges b/doc/APIchanges
> >>>>> index 1d6cc36..7cad7fa 100644
> >>>>> --- a/doc/APIchanges
> >>>>> +++ b/doc/APIchanges
> >>>>> @@ -15,6 +15,9 @@ libavutil: 2017-10-21
> >>>>>
> >>>>> API changes, most recent first:
> >>>>>
> >>>>> +2020-06-xx - xxxxxxxxxx - lavc 58.94.100 - packet.h
> >>>>> + Add AV_PKT_DATA_S12M_TIMECODE.
> >>>>> +
> >>>>> 2020-06-12 - b09fb030c1 - lavu 56.55.100 - pixdesc.h
> >>>>> Add AV_PIX_FMT_X2RGB10.
> >>>>>
> >>>>> diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
> >>>>> index dce26cb..24e2a74 100644
> >>>>> --- a/libavcodec/avpacket.c
> >>>>> +++ b/libavcodec/avpacket.c
> >>>>> @@ -400,6 +400,7 @@ const char *av_packet_side_data_name(enum AVPacketSideDataType type)
> >>>>> case AV_PKT_DATA_PRFT: return "Producer Reference Time";
> >>>>> case AV_PKT_DATA_ICC_PROFILE: return "ICC Profile";
> >>>>> case AV_PKT_DATA_DOVI_CONF: return "DOVI configuration record";
> >>>>> + case AV_PKT_DATA_S12M_TIMECODE: return "SMPTE ST 12-1:2014 timecode";
> >>>>> }
> >>>>> return NULL;
> >>>>> }
> >>>>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
> >>>>> index de9c079..f2244fc 100644
> >>>>> --- a/libavcodec/decode.c
> >>>>> +++ b/libavcodec/decode.c
> >>>>> @@ -1699,6 +1699,7 @@ int ff_decode_frame_props(AVCodecContext *avctx, AVFrame *frame)
> >>>>> { AV_PKT_DATA_CONTENT_LIGHT_LEVEL, AV_FRAME_DATA_CONTENT_LIGHT_LEVEL },
> >>>>> { AV_PKT_DATA_A53_CC, AV_FRAME_DATA_A53_CC },
> >>>>> { AV_PKT_DATA_ICC_PROFILE, AV_FRAME_DATA_ICC_PROFILE },
> >>>>> + { AV_PKT_DATA_S12M_TIMECODE, AV_FRAME_DATA_S12M_TIMECODE },
> >>>>> };
> >>>>>
> >>>>> if (pkt) {
> >>>>> diff --git a/libavcodec/packet.h b/libavcodec/packet.h
> >>>>> index 96f237f..d84aaaa 100644
> >>>>> --- a/libavcodec/packet.h
> >>>>> +++ b/libavcodec/packet.h
> >>>>> @@ -283,6 +283,12 @@ enum AVPacketSideDataType {
> >>>>> AV_PKT_DATA_DOVI_CONF,
> >>>>>
> >>>>> /**
> >>>>> + * Timecode which conforms to SMPTE ST 12-1:2014. The data is an array of 4 uint32_t
> >>>>> + * where the first uint32_t describes how many (1-3) of the other timecodes are used.
> >>>>> + */
> >>>>
> >>>> You should move the doc to timecode.h first in a separate patch and then
> >>>> reference the documentation here.
> >>>
> >>> I'm not native English, so it's difficult for me to describe the format of timecode in comments clearly.
> >>> As it's defined in SMPTE ST 12-1:2014, so I think it's enough as it says conforms to SMPTE ST 12-1:2014
> >>> at beginning.
> >>>
> >>
> >> Could you please point me to the part of SMPTE ST 12-1:2014 that
> >> describes the format that we use here? Because AFAIK SMPTE ST 12-1:2014
> >> just defines what fields a SMPTE ST 12-1 message has (and what
> >> semantics), but leaves the rest (the actual framing) to other standards:
> >>
> >> "The actual transport of the codewords for digital systems varies
> >> significantly from the transport methods defined for analog systems, and
> >> is defined in the associated document, SMPTE ST 12-2."
> >>
> >> E.g. RTP uses a different framing (see RFC 5484); obviously every
> >> framing method used for transport must prescribe endianness of not
> >> depend upon endianness; yet our method does. (Isn't this actually a
> >> problem for fate-tests because framecrc calculates checksums for side date?)
> >
> > So the transport format is using SMPTE ST 12-2? I'm not sure about it. It's
> > better to say which standard are using in comments, it's not private format.
> > Now I'm just using the timecode.[ch], so it's difficult to give comments for
> > its format. For HEVC timecode, it's use little endianness.
> >
>
> No, av_timecode_get_smpte seems to use a custom format, not SMPTE ST
> 12-2. That's why it is so important to actually document it.
av_timecode_get_smpte() is coming from h264_slice. In fact, I have plan to remove the
duplicate code with av_timecode_get_smpte_from_framenum().
So the real format which is refer by the orignal author is av_timecode_get_smpte_from_framenum()
To keep things going, I can add more format description for av_timecode_get_smpte_from_framenum()
by the code. Please correct it if it's not OK. Now the format is used by local
system only, that's why the byte order isn't considered I think.
>
> >>
> >>>>
> >>>>> + AV_PKT_DATA_S12M_TIMECODE,
> >>>>> +
> >>>>> + /**
> >>>>> * The number of side data types.
> >>>>> * This is not part of the public API/ABI in the sense that it may
> >>>>> * change when new side data types are added.
> >>>>> diff --git a/libavcodec/version.h b/libavcodec/version.h
> >>>>> index 0359302..482cc6d 100644
> >>>>> --- a/libavcodec/version.h
> >>>>> +++ b/libavcodec/version.h
> >>>>> @@ -28,7 +28,7 @@
> >>>>> #include "libavutil/version.h"
> >>>>>
> >>>>> #define LIBAVCODEC_VERSION_MAJOR 58
> >>>>> -#define LIBAVCODEC_VERSION_MINOR 93
> >>>>> +#define LIBAVCODEC_VERSION_MINOR 94
> >>>>> #define LIBAVCODEC_VERSION_MICRO 100
> >>>>>
> >>>>> #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
> >>>>> diff --git a/libavformat/dump.c b/libavformat/dump.c
> >>>>> index 117c681..0f64c4f 100644
> >>>>> --- a/libavformat/dump.c
> >>>>> +++ b/libavformat/dump.c
> >>>>> @@ -34,6 +34,7 @@
> >>>>> #include "libavutil/replaygain.h"
> >>>>> #include "libavutil/spherical.h"
> >>>>> #include "libavutil/stereo3d.h"
> >>>>> +#include "libavutil/timecode.h"
> >>>>>
> >>>>> #include "avformat.h"
> >>>>>
> >>>>> @@ -402,6 +403,22 @@ static void dump_dovi_conf(void *ctx, AVPacketSideData* sd)
> >>>>> dovi->dv_bl_signal_compatibility_id);
> >>>>> }
> >>>>>
> >>>>> +static void dump_s12m_timecode(void *ctx, AVPacketSideData* sd)
> >>>>
> >>>> * belongs to the variable, not the type.
OK, got it
> >>>>
> >>>>> +{
> >>>>> + uint32_t *tc = (uint32_t*)sd->data;
> >>>>> +
> >>>>> + if ((sd->size != sizeof(uint32_t) * 4) || (tc[0] > 3)) {
> >>>>> + av_log(ctx, AV_LOG_ERROR, "invalid data\n");
> >>>>> + return;
> >>>>> + }
> >>>>> +
> >>>>> + for (int j = 1; j <= tc[0]; j++) {
> >>>>> + char tcbuf[AV_TIMECODE_STR_SIZE];
> >>>>> + av_timecode_make_smpte_tc_string(tcbuf, tc[j], 0);
> >>>>> + av_log(ctx, AV_LOG_INFO, "timecode - %s%s", tcbuf, j != tc[0] ? ", " : "");
> >>>>> + }
> >>>>> +}
> >>>>> +
> >>>>> static void dump_sidedata(void *ctx, AVStream *st, const char *indent)
> >>>>> {
> >>>>> int i;
> >>>>> @@ -468,6 +485,10 @@ static void dump_sidedata(void *ctx, AVStream *st, const char *indent)
> >>>>> av_log(ctx, AV_LOG_INFO, "DOVI configuration record: ");
> >>>>> dump_dovi_conf(ctx, &sd);
> >>>>> break;
> >>>>> + case AV_PKT_DATA_S12M_TIMECODE:
> >>>>> + av_log(ctx, AV_LOG_INFO, "SMPTE ST 12-1:2014: ");
> >>>>> + dump_s12m_timecode(ctx, &sd);
> >>>>> + break;
> >>>>> default:
> >>>>> av_log(ctx, AV_LOG_INFO,
> >>>>> "unknown side data type %d (%d bytes)", sd.type, sd.size);
> >>>>>
> >>>>
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>
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--
Thanks,
Limin Wang
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