avio_skip(pb, 8);
av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
avio_skip(pb, 8);
av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);