[Ffmpeg-devel] Audio and Video Frame Start/End Time
Thu Oct 6 17:51:52 CEST 2005
I have moved on to the next level of this application. Basically, it
uses ffmpeg to read an MPEG2 stream, and pass the decoded audio and
video to the Helix Producer SDK. This works, but I'm having some
problems obtaining timing information.
The Helix SDK requires a start time and end time (in milliseconds) for
each "sample" provided. So, for example, I decode the audio, use the
pkt.pts, and calculate the audio "end time" based on channels & sample rate.
The video, however, is posing a problem. Since (as I read in an earlier
thread) that the AVPacket.pts value is not necessarily valid, I need to
calculate the video timing myself.
My question is whether each frame decoded represents one frame of video
at the input frame rate. In other words, if I keep a count of the number
of frames decoded, and calculate the start and end times based on the
frame rate, is this the correct method? Have others found this same problem?
Should I be calculating the audio timing the same way?
Should the timings start at zero?
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