c++ - IMediaSample Time and MediaTime -
what primary difference between settime , setmediatime?
right in directshow livesource calculate time this
reference_time rtstart = m_rtlastsampletime; m_rtlastsampletime += pvih->avgtimeperframe; pms->settime(&rtstart, &m_rtlastsampletime); pms->setsyncpoint(true); pms->setdiscontinuity(rtstart <= 1);
this doesn't work encoders.
i've noticed source work these encoders set mediatime , seem jump up.
optionally, filter can specify media time sample. in video stream, media time represents frame number. in audio stream, media time represents sample number in packet. example, if each packet contains 1 second of 44.1 kilohertz (khz) audio, first packet has media start time of 0 , media stop time of 44100. in seekable stream, media time relative start time of stream. example, suppose seek 2 seconds start of 15-fps video stream. first media sample after seek has time stamp of 0 media time of 30.
renderer , mux filters can use media time determine whether frames or samples have been dropped, checking gaps. however, filters not required set media time. set media time on sample, call imediasample::setmediatime method.
i don't think used anywhere. settime
, on contrary, important.
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