Fixed issue417.

Originally committed as revision 13405 to svn://svn.ffmpeg.org/ffmpeg/trunk

This is more efficient as in practice the check is redundant most of the
time. Callers which do not know if enough data is available have to check
it with av_fifo_size(). Doing the check in *read() means the caller has
no choice to skip the check when its known to be redundant.
Also the return value was never documented in a public header so
changing it should not break the API. Besides this fixes the case where
read() failed on a 100% full fifo.

Originally committed as revision 13404 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13403 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13402 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13401 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13400 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13399 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13398 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13397 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13396 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13395 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13394 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13393 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13392 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13391 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13390 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13389 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13388 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13387 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13386 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13385 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13384 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13383 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13382 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13381 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13380 to svn://svn.ffmpeg.org/ffmpeg/trunk

Patch by Jeremy Kolb.

Originally committed as revision 13379 to svn://svn.ffmpeg.org/ffmpeg/trunk

Fixes issue323.

Originally committed as revision 13378 to svn://svn.ffmpeg.org/ffmpeg/trunk

Fixes issue371.

Originally committed as revision 13377 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13376 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13375 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13374 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13373 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13372 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13371 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13370 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13369 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13368 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13367 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13366 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13365 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13364 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13363 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13362 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 13361 to svn://svn.ffmpeg.org/ffmpeg/trunk

Commited in SoC by Vitor Sessak on 2008-05-24 17:20:09

Originally committed as revision 13360 to svn://svn.ffmpeg.org/ffmpeg/trunk

Commited in SoC by Vitor Sessak on 2008-05-24 17:18:03

Originally committed as revision 13359 to svn://svn.ffmpeg.org/ffmpeg/trunk

Commited in SoC by Vitor Sessak on 2008-05-24 17:17:19

Originally committed as revision 13358 to svn://svn.ffmpeg.org/ffmpeg/trunk

Commited in SoC by Vitor Sessak on 2008-05-24 17:15:18

Originally committed as revision 13357 to svn://svn.ffmpeg.org/ffmpeg/trunk

Commited in SoC by Vitor Sessak on 2008-05-24 17:01:01

Originally committed as revision 13356 to svn://svn.ffmpeg.org/ffmpeg/trunk