ffmdec: handle wrapped file in ffm_seek

This commit is contained in:
Yan Jing 2011-09-08 20:09:40 +02:00 committed by Michael Niedermayer
parent 6337de9252
commit 59810f8388
1 changed files with 16 additions and 2 deletions

View File

@ -461,11 +461,25 @@ static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, in
av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
/* find the position using linear interpolation (better than
dichotomy in typical cases) */
if (ffm->write_index < ffm->file_size) {
if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
pos_min = FFM_PACKET_SIZE;
pos_max = ffm->write_index - FFM_PACKET_SIZE;
} else {
pos_min = ffm->write_index;
pos_max = ffm->file_size - FFM_PACKET_SIZE;
}
} else {
pos_min = FFM_PACKET_SIZE;
pos_max = ffm->file_size - FFM_PACKET_SIZE;
}
while (pos_min <= pos_max) {
pts_min = get_dts(s, pos_min);
pts_max = get_dts(s, pos_max);
if (pts_min > wanted_pts || pts_max < wanted_pts) {
pos = pts_min > wanted_pts ? pos_min : pos_max;
goto found;
}
/* linear interpolation */
pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
(double)(pts_max - pts_min);