[FFmpeg-devel] [PATCH 2/3] ffplay: remove early frame drop functionality

Michael Niedermayer michaelni at gmx.at
Mon Oct 10 22:43:12 CEST 2011

On Mon, Oct 10, 2011 at 08:59:09PM +0200, Marton Balint wrote:
> The current impementation of early frame drops (dropping frames before adding
> them to the picture queue) has multiple problems:
> Even after gettin A-V sync, the frame droping continues until
> VideoState->skip_frames reaches 1, which can take a lot of time causing useless
> additional frame drops and bad AV-sync. This issue can be easily triggered with
> for example changing the audio stream.
> Also video_refresh currenly does not handle early skipped frames in every case,
> for example if we skip a frame, then the last frame duration calculation will
> compute the duration of the sum of the skipped frame and the duration of the
> frame before that, and in compute_target_delay we may multiply this unusually
> big delay.

The current early frame drop code has 2 reasons for its existence.
if the filtering is very timeconsuming and cannot be performed
in realtime AV sync is not possible with droping after the filtering.

and when realtime display of all frames is not possibly it is better
to drop a consistent and evenly distributed pattern of frames instead
of a inconsistent one like for example droping several consecutive
frames and then not droping several in a row

do you see an alternative to droping it ?

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20111010/82950765/attachment.asc>

More information about the ffmpeg-devel mailing list