The dshow plugin ignores timestamps for video frames provided by the DirectShow
device, instead using wallclock time, apparently because the implementer of
this code had a device that provided unreliable timestamps. Me (and others)
would like to use the device's timestamps. The new use_video_device_timestamps
option for dshow device enables them to do so. Since the majority of video
devices out there probably provide fine timestamps, this patch sets the default
to using the device timestamps, which means best fidelity timestamps are used
by default. Using the new option, the user can switch this off and revert to
the old behavior, so a fall back remains available in case the device provides
broken timestamps.
Closes: #8620
Signed-off-by: Diederick Niehorster <dcni...@gmail.com>
---
libavdevice/dshow.c | 1 +
libavdevice/dshow_capture.h | 1 +
libavdevice/dshow_pin.c | 15 ++++++++-------
3 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/libavdevice/dshow.c b/libavdevice/dshow.c
index 8d0a6fcc09..2e9f9ddf3f 100644
--- a/libavdevice/dshow.c
+++ b/libavdevice/dshow.c
@@ -1317,6 +1317,7 @@ static const AVOption options[] = {
{ "audio_device_save", "save audio capture filter device (and properties)
to file", OFFSET(audio_filter_save_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0,
0, DEC },
{ "video_device_load", "load video capture filter device (and properties)
from file", OFFSET(video_filter_load_file), AV_OPT_TYPE_STRING, {.str = NULL},
0, 0, DEC },
{ "video_device_save", "save video capture filter device (and properties)
to file", OFFSET(video_filter_save_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0,
0, DEC },
+ { "use_video_device_timestamps", "use device instead of wallclock
timestamps for video frames", OFFSET(use_video_device_timestamps),
AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, DEC },
{ NULL },
};
diff --git a/libavdevice/dshow_capture.h b/libavdevice/dshow_capture.h
index 06ded2ba96..5a2691518c 100644
--- a/libavdevice/dshow_capture.h
+++ b/libavdevice/dshow_capture.h
@@ -312,6 +312,7 @@ struct dshow_ctx {
char *audio_filter_save_file;
char *video_filter_load_file;
char *video_filter_save_file;
+ int use_video_device_timestamps;
IBaseFilter *device_filter[2];
IPin *device_pin[2];
diff --git a/libavdevice/dshow_pin.c b/libavdevice/dshow_pin.c
index 3dae405e65..ab0ead8041 100644
--- a/libavdevice/dshow_pin.c
+++ b/libavdevice/dshow_pin.c
@@ -309,12 +309,16 @@ long ff_dshow_meminputpin_Receive(DShowMemInputPin *this,
IMediaSample *sample)
if (!sample)
return E_POINTER;
+ priv_data = pin->filter->priv_data;
+ s = priv_data;
+ ctx = s->priv_data;
+
IMediaSample_GetTime(sample, &orig_curtime, &dummy);
orig_curtime += pin->filter->start_time;
IReferenceClock_GetTime(clock, &graphtime);
- if (devtype == VideoDevice) {
- /* PTS from video devices is unreliable. */
- IReferenceClock_GetTime(clock, &curtime);
+ if (devtype == VideoDevice && !ctx->use_video_device_timestamps) {
+ /* PTS from video devices is unreliable. */
+ IReferenceClock_GetTime(clock, &curtime);
} else {
IMediaSample_GetTime(sample, &curtime, &dummy);
if(curtime > 400000000000000000LL) {
@@ -322,7 +326,7 @@ long ff_dshow_meminputpin_Receive(DShowMemInputPin *this,
IMediaSample *sample)
like 437650244077016960 which FFmpeg doesn't like.
TODO figure out math. For now just drop them. */
av_log(NULL, AV_LOG_DEBUG,
- "dshow dropping initial (or ending) audio frame with odd PTS
too high %"PRId64"\n", curtime);
+ "dshow dropping initial (or ending) frame with odd PTS too
high %"PRId64"\n", curtime);
return S_OK;
}
curtime += pin->filter->start_time;
@@ -330,9 +334,6 @@ long ff_dshow_meminputpin_Receive(DShowMemInputPin *this,
IMediaSample *sample)
buf_size = IMediaSample_GetActualDataLength(sample);
IMediaSample_GetPointer(sample, &buf);
- priv_data = pin->filter->priv_data;
- s = priv_data;
- ctx = s->priv_data;
index = pin->filter->stream_index;
av_log(NULL, AV_LOG_VERBOSE, "dshow passing through packet of type %s size
%8d "
--
2.28.0.windows.1
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