[FFmpeg-devel] [PATCH v3 1/2] API: add AV_PKT_DATA_S12M_TIMECODE to AVPacketSideDataType
Andreas Rheinhardt
andreas.rheinhardt at gmail.com
Tue Jun 30 02:54:06 EEST 2020
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_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.
>>>>
>>>>> +{
>>>>> + 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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