[FFmpeg-devel] [PATCH v2 3/3] avdevice/decklink: addition of absolute wallclock option for pts source

[Marton Balint]

On Wed, 10 Jan 2018, vdixit at akamai.com wrote:

> From: Vishwanath Dixit <vdixit at akamai.com>
>
> ---
> doc/indevs.texi                 | 6 ++++--
> libavdevice/decklink_common_c.h | 1 +
> libavdevice/decklink_dec.cpp    | 4 ++++
> libavdevice/decklink_dec_c.c    | 1 +
> 4 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/doc/indevs.texi b/doc/indevs.texi
> index 36aef49..0bc8e6a 100644
> --- a/doc/indevs.texi
> +++ b/doc/indevs.texi
> @@ -298,11 +298,13 @@ Sets the audio input source. Must be @samp{unset}, @samp{embedded},
> 
> @item video_pts
> Sets the video packet timestamp source. Must be @samp{video}, @samp{audio},
> - at samp{reference} or @samp{wallclock}. Defaults to @samp{video}.
> + at samp{reference}, @samp{wallclock} or @samp{abs_wallclock}.
> +Defaults to @samp{video}.
> 
> @item audio_pts
> Sets the audio packet timestamp source. Must be @samp{video}, @samp{audio},
> - at samp{reference} or @samp{wallclock}. Defaults to @samp{audio}.
> + at samp{reference}, @samp{wallclock} or @samp{abs_wallclock}.
> +Defaults to @samp{audio}.
> 
> @item draw_bars
> If set to @samp{true}, color bars are drawn in the event of a signal loss.
> diff --git a/libavdevice/decklink_common_c.h b/libavdevice/decklink_common_c.h
> index 18097e2..08e9f9b 100644
> --- a/libavdevice/decklink_common_c.h
> +++ b/libavdevice/decklink_common_c.h
> @@ -28,6 +28,7 @@ typedef enum DecklinkPtsSource {
>     PTS_SRC_VIDEO     = 2,
>     PTS_SRC_REFERENCE = 3,
>     PTS_SRC_WALLCLOCK = 4,
> +    PTS_SRC_ABS_WALLCLOCK = 5,
>     PTS_SRC_NB
> } DecklinkPtsSource;
> 
> diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
> index 1fd40ca..c6eea43 100644
> --- a/libavdevice/decklink_dec.cpp
> +++ b/libavdevice/decklink_dec.cpp
> @@ -607,6 +607,8 @@ static int64_t get_pkt_pts(IDeckLinkVideoInputFrame *videoFrame,
>                 res = videoFrame->GetHardwareReferenceTimestamp(time_base.den, &bmd_pts, &bmd_duration);
>             break;
>         case PTS_SRC_WALLCLOCK:
> +            /* fall through */
> +        case PTS_SRC_ABS_WALLCLOCK:
>         {
>             /* MSVC does not support compound literals like AV_TIME_BASE_Q
>              * in C++ code (compiler error C4576) */
> @@ -652,6 +654,8 @@ HRESULT decklink_input_callback::VideoInputFrameArrived(
>     ctx->frameCount++;
>     if (ctx->audio_pts_source == PTS_SRC_WALLCLOCK || ctx->video_pts_source == PTS_SRC_WALLCLOCK)
>         wallclock = av_gettime_relative();
> +    else if (ctx->audio_pts_source == PTS_SRC_ABS_WALLCLOCK || ctx->video_pts_source == PTS_SRC_ABS_WALLCLOCK)
> +        wallclock = av_gettime();

This logic is not entirely correct, the user may request abs_wallclock as 
video pts source, and wallclock as audio... So this "if" should be on its 
own assigning a different variable, (e.g. abs_wallclock) and 
you need to pass that to get_pkt_pts as well.

>
>     // Handle Video Frame
>     if (videoFrame) {
> diff --git a/libavdevice/decklink_dec_c.c b/libavdevice/decklink_dec_c.c
> index d52dde5..00fb3af 100644
> --- a/libavdevice/decklink_dec_c.c
> +++ b/libavdevice/decklink_dec_c.c
> @@ -70,6 +70,7 @@ static const AVOption options[] = {
>     { "video",         NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_VIDEO    }, 0, 0, DEC, "pts_source"},
>     { "reference",     NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_REFERENCE}, 0, 0, DEC, "pts_source"},
>     { "wallclock",     NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_WALLCLOCK}, 0, 0, DEC, "pts_source"},
> +    { "abs_wallclock", NULL,                                          0,  AV_OPT_TYPE_CONST, { .i64 = PTS_SRC_ABS_WALLCLOCK}, 0, 0, DEC, "pts_source"},
>     { "draw_bars",     "draw bars on signal loss" , OFFSET(draw_bars),    AV_OPT_TYPE_BOOL,  { .i64 = 1}, 0, 1, DEC },
>     { "queue_size",    "input queue buffer size",   OFFSET(queue_size),   AV_OPT_TYPE_INT64, { .i64 = (1024 * 1024 * 1024)}, 0, INT64_MAX, DEC },
>     { "audio_depth",   "audio bitdepth (16 or 32)", OFFSET(audio_depth),  AV_OPT_TYPE_INT,   { .i64 = 16}, 16, 32, DEC },

Regards,
Marton