[FFmpeg-devel] h264 ts without timing and analyze duration

Michael Niedermayer michaelni
Wed Dec 10 22:03:45 CET 2008

On Wed, Dec 10, 2008 at 01:49:57PM -0500, Matthew Eaton wrote:
> When processing an h264 (ts) stream without timing info (sps
> timing_info_present_flag = 0), analyzeduration/max_analyze_duration is
> not used in av_find_stream_info().

There is no h264 in mpeg-ts/ps without some kind of timing, we do lack
a parser extracting it, a fix for this is welcome

> As a result, the analyze loop aborts when MAX_READ_SIZE is reached.
> This takes much longer than the maximum analyze duration (about 20
> seconds on a 2 megabit stream).
> Attached is a patch that uses dts to estimate the elapsed duration
> when the packet duration is unknown. It's less than optimal, but fps
> has not been calculated/estimated at that point in the function.

this could cause problems in respect to timestamp discontinuities,
that is a discontinuity could cause an early exit of this loop

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct awnser.
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