[MPlayer-dev-eng] [Patch] Even better seeking in ogg ;-)

[Moritz Bunkus]

Hi,

File 1 (Band of Brothers, the one I uploaded the sample from), without
-forceidx:

- (1) Seeking forward can get stuck, e.g. i am at 2:20, and seeking
forward does not work with +10 nor with +60. With +600 it does work. In
fact, seeking with +60 or +10 toggles between two key frames at 2:04 and
2:20.

- (2) Seeking forward near the very end of the file will not seek to a
key frame. libavcodec will complain about the first frame it gets not
being a key frame, and the picture has its typical 'first frame is not a
keyframe' problem. This happens with the +600, not with the +10, though.

- Seeking backwards seems to work fine, though.

File 1, with -forceidx:

- Seeking is generally fine. The problem with being stuck at 2:20 does
not appear. (2) from above still happens, though.

- I get this funny message: 'Invalid granulepos 1651666806 at start'
Well, checking with ogminfo shows that there is no such granulepos for
the packets that contain data. Maybe it is for one of the header/comment
packets, but you mustn't use those for the syncpoints anyway. I guess
this is why you said...

> Your file starts with invalid granulepos. I made the scanner jump over
> the first if it is larger than the second.

Knowing how I'v written the ogmtools I am VERY sure that for any given
stream the granulepos values never decrease inbetween.


File 2 (Dazed and Confused, uploading a sample at the moment:
http://www.bunkus.org/dazed-short.ogm), without -forceidx:

- (1) Right at the beginning I cannot seek +10, it always drops me to
0:00 again. Seeking +60 works.

- (2) Around 0:40 I cannot seek backward to 0:00 with -10. It will drop
me to 0:19, hitting -10 again will drop me to 0:40 again. Seeking -60
will drop me to 0:00 as expected. This is a minor issue, IMHO.

Same file, with -forceidx:

- (1) At 1:36 seeking +10 drops me back to 1:36. Seeking +60 works. Same
at 2:32.
- (2) Same 'first frame is not a key frame' issue as with file 1.


Summary:

Seeking backwards usually works a lot better than without your
patch. Seeking forward, however, is really broken. Seeking forward
should ALWAYS be possible.

The crashes are gone, though.

Mosu

-- 
If Darl McBride was in charge, he'd probably make marriage
unconstitutional too, since clearly it de-emphasizes the commercial
nature of normal human interaction, and probably is a major impediment
to the commercial growth of prostitution. - Linus Torvalds
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/attachments/20040229/dea1d3c6/attachment.pgp>